* [PATCH v3 01/17] f2fs: extend folio state for large folio write path
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
@ 2026-10-09 16:12 ` Nanzhe Zhao
2026-10-09 16:12 ` [PATCH v3 02/17] f2fs: carry subpage offset and count in write IO Nanzhe Zhao
` (15 subsequent siblings)
16 siblings, 0 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:12 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
Large folio write path needs a subpage status bitmap and write
pages pending counter, while keeping compatible with f2fs private
flags.
Move struct f2fs_folio_state to f2fs.h, add private_flags and
subpage state bitmap, and change PAGE_PRIVATE functions to be
compatible with f2fs_folio_state. Allocate f2fs_folio_state via kzalloc
instead of kmem_cache, since the state size depends on the folio order.
Note: Now if a path wants to use f2fs_folio_state, it must call
`folio_has_ffs` instead of `folio_test_large`` to make check.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 52 ++++++++++++++++++++-----------------
fs/f2fs/f2fs.h | 70 +++++++++++++++++++++++++++++++++++++-------------
2 files changed, 80 insertions(+), 42 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 6d4ba5e77906..6c12f58d4f9f 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -32,15 +32,9 @@
static struct kmem_cache *bio_post_read_ctx_cache;
static struct kmem_cache *bio_entry_slab;
-static struct kmem_cache *ffs_entry_slab;
static mempool_t *bio_post_read_ctx_pool;
static struct bio_set f2fs_bioset;
-struct f2fs_folio_state {
- spinlock_t state_lock;
- unsigned int read_pages_pending;
-};
-
#define F2FS_BIO_POOL_SIZE NR_CURSEG_TYPE
int __init f2fs_init_bioset(void)
@@ -2704,17 +2698,31 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
}
#endif
-static struct f2fs_folio_state *ffs_find_or_alloc(struct folio *folio)
+struct f2fs_folio_state *f2fs_ffs_find_or_alloc(struct folio *folio)
{
- struct f2fs_folio_state *ffs = folio->private;
+ struct f2fs_folio_state *ffs;
+ unsigned int nr_subpages = folio_nr_pages(folio);
+ unsigned long private = (unsigned long)folio->private;
- if (ffs)
- return ffs;
+ f2fs_bug_on(F2FS_F_SB(folio), !folio_test_large(folio));
+ f2fs_bug_on(F2FS_F_SB(folio),
+ test_bit(PAGE_PRIVATE_NOT_POINTER, &private));
- ffs = f2fs_kmem_cache_alloc(ffs_entry_slab,
- GFP_NOIO | __GFP_ZERO, true, NULL);
+ if (f2fs_folio_has_ffs(folio))
+ return (struct f2fs_folio_state *)folio->private;
+
+ ffs = f2fs_kmalloc(F2FS_F_SB(folio),
+ struct_size(ffs, state, BITS_TO_LONGS(2 * nr_subpages)),
+ GFP_NOFS | __GFP_ZERO);
+ if (!ffs)
+ return NULL;
spin_lock_init(&ffs->state_lock);
+ if (folio_test_uptodate(folio))
+ bitmap_set(ffs->state, 0, nr_subpages);
+ if (folio_test_dirty(folio))
+ bitmap_set(ffs->state, nr_subpages, nr_subpages);
+
folio_attach_private(folio, ffs);
return ffs;
}
@@ -2723,7 +2731,7 @@ static void ffs_detach_free(struct folio *folio)
{
struct f2fs_folio_state *ffs;
- if (!folio_test_large(folio)) {
+ if (!f2fs_folio_has_ffs(folio)) {
folio_detach_private(folio);
return;
}
@@ -2733,7 +2741,8 @@ static void ffs_detach_free(struct folio *folio)
return;
WARN_ON_ONCE(ffs->read_pages_pending != 0);
- kmem_cache_free(ffs_entry_slab, ffs);
+ WARN_ON_ONCE(atomic_read(&ffs->write_pages_pending));
+ kfree(ffs);
}
static int f2fs_read_data_large_folio(struct inode *inode,
@@ -2822,7 +2831,11 @@ static int f2fs_read_data_large_folio(struct inode *inode,
* to prevent from premature folio_end_read() call on folio
*/
if (folio_test_large(folio)) {
- ffs = ffs_find_or_alloc(folio);
+ ffs = f2fs_ffs_find_or_alloc(folio);
+ if (!ffs) {
+ ret = -ENOMEM;
+ goto err_out;
+ }
/* set the bitmap to wait */
spin_lock_irq(&ffs->state_lock);
@@ -4733,21 +4746,12 @@ int __init f2fs_init_bio_entry_cache(void)
if (!bio_entry_slab)
return -ENOMEM;
- ffs_entry_slab = f2fs_kmem_cache_create("f2fs_ffs_slab",
- sizeof(struct f2fs_folio_state));
-
- if (!ffs_entry_slab) {
- kmem_cache_destroy(bio_entry_slab);
- return -ENOMEM;
- }
-
return 0;
}
void f2fs_destroy_bio_entry_cache(void)
{
kmem_cache_destroy(bio_entry_slab);
- kmem_cache_destroy(ffs_entry_slab);
}
static int f2fs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 089a62c054ea..270b1d556e45 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1621,6 +1621,18 @@ static inline void f2fs_clear_bit(unsigned int nr, char *addr);
* Layout B: lowest bit should be 0
* page.private is a wrapped pointer.
*/
+
+struct f2fs_folio_state {
+ spinlock_t state_lock;
+ unsigned int read_pages_pending;
+ atomic_t write_pages_pending;
+ unsigned long private_flags;
+ /* state[0..nr_subpages - 1] tracks uptodate subpages.
+ * state[nr_subpages..2 * nr_subpages - 1] tracks dirty subpages.
+ */
+ unsigned long state[];
+};
+
enum {
PAGE_PRIVATE_NOT_POINTER, /* private contains non-pointer data */
PAGE_PRIVATE_ONGOING_MIGRATION, /* data page which is on-going migrating */
@@ -1629,6 +1641,13 @@ enum {
PAGE_PRIVATE_MAX
};
+static inline bool f2fs_folio_has_ffs(const struct folio *folio)
+{
+ unsigned long private = (unsigned long)folio->private;
+
+ return folio_test_large(folio) && private;
+}
+
/* For compression */
enum compress_algorithm_type {
COMPRESS_LZO,
@@ -2756,13 +2775,35 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
return -ENOSPC;
}
+static inline unsigned long f2fs_folio_get_private_flags(const struct folio *folio)
+{
+ unsigned long private = (unsigned long)folio->private;
+
+ if (f2fs_folio_has_ffs(folio)) {
+ struct f2fs_folio_state *ffs = (struct f2fs_folio_state *)private;
+
+ return READ_ONCE(ffs->private_flags);
+ }
+
+ if (test_bit(PAGE_PRIVATE_NOT_POINTER, &private))
+ return private;
+
+ return 0;
+}
+
+static inline unsigned long *f2fs_folio_flags_addr(struct folio *folio)
+{
+ if (f2fs_folio_has_ffs(folio))
+ return &((struct f2fs_folio_state *)folio->private)->private_flags;
+
+ return (unsigned long *)&folio->private;
+}
+
#define PAGE_PRIVATE_GET_FUNC(name, flagname) \
static inline bool folio_test_f2fs_##name(const struct folio *folio) \
{ \
- unsigned long priv = (unsigned long)folio->private; \
- unsigned long v = (1UL << PAGE_PRIVATE_NOT_POINTER) | \
- (1UL << PAGE_PRIVATE_##flagname); \
- return (priv & v) == v; \
+ return f2fs_folio_get_private_flags(folio) & \
+ (1UL << PAGE_PRIVATE_##flagname); \
} \
static inline bool page_private_##name(struct page *page) \
{ \
@@ -2774,14 +2815,10 @@ static inline bool page_private_##name(struct page *page) \
#define PAGE_PRIVATE_SET_FUNC(name, flagname) \
static inline void folio_set_f2fs_##name(struct folio *folio) \
{ \
- unsigned long v = (1UL << PAGE_PRIVATE_NOT_POINTER) | \
- (1UL << PAGE_PRIVATE_##flagname); \
if (!folio->private) \
- folio_attach_private(folio, (void *)v); \
- else { \
- v |= (unsigned long)folio->private; \
- folio->private = (void *)v; \
- } \
+ folio_attach_private(folio, \
+ (void *)BIT(PAGE_PRIVATE_NOT_POINTER)); \
+ set_bit(PAGE_PRIVATE_##flagname, f2fs_folio_flags_addr(folio)); \
} \
static inline void set_page_private_##name(struct page *page) \
{ \
@@ -2794,13 +2831,10 @@ static inline void set_page_private_##name(struct page *page) \
#define PAGE_PRIVATE_CLEAR_FUNC(name, flagname) \
static inline void folio_clear_f2fs_##name(struct folio *folio) \
{ \
- unsigned long v = (unsigned long)folio->private; \
- \
- v &= ~(1UL << PAGE_PRIVATE_##flagname); \
- if (v == (1UL << PAGE_PRIVATE_NOT_POINTER)) \
+ clear_bit(PAGE_PRIVATE_##flagname, \
+ f2fs_folio_flags_addr(folio)); \
+ if (folio->private == (void *)BIT(PAGE_PRIVATE_NOT_POINTER)) \
folio_detach_private(folio); \
- else \
- folio->private = (void *)v; \
} \
static inline void clear_page_private_##name(struct page *page) \
{ \
@@ -2823,7 +2857,7 @@ PAGE_PRIVATE_CLEAR_FUNC(atomic, ATOMIC_WRITE);
static inline unsigned long folio_get_f2fs_data(struct folio *folio)
{
- unsigned long data = (unsigned long)folio->private;
+ unsigned long data = f2fs_folio_get_private_flags(folio);
if (!test_bit(PAGE_PRIVATE_NOT_POINTER, &data))
return 0;
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* [PATCH v3 02/17] f2fs: carry subpage offset and count in write IO
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
2026-10-09 16:12 ` [PATCH v3 01/17] f2fs: extend folio state for large folio write path Nanzhe Zhao
@ 2026-10-09 16:12 ` Nanzhe Zhao
2026-10-09 16:12 ` [PATCH v3 03/17] f2fs: support regular file buffered writes on large folios Nanzhe Zhao
` (14 subsequent siblings)
16 siblings, 0 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:12 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
Large folio write paths need to submit I/O for a range inside a
folio instead of always submitting the whole folio from offset zero.
Add folio_offset and folio_blkcnt to f2fs_io_info to describe the
block offset inside the folio and the number of contiguous blocks
covered by the I/O.
Apply the new fields to the bio submit paths that need the subpage
offset or contiguous block count.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/checkpoint.c | 2 ++
fs/f2fs/compress.c | 1 +
fs/f2fs/data.c | 63 +++++++++++++++++++++++++++++++-------------
fs/f2fs/f2fs.h | 11 ++++++++
fs/f2fs/gc.c | 2 ++
fs/f2fs/inline.c | 1 +
fs/f2fs/segment.c | 3 ++-
7 files changed, 63 insertions(+), 20 deletions(-)
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 7b89bb838946..81c1c2de936f 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -264,6 +264,7 @@ static struct f2fs_cached_block *__get_meta_cache(struct f2fs_sb_info *sbi,
.op_flags = REQ_META | REQ_PRIO,
.old_blkaddr = index,
.new_blkaddr = index,
+ .folio_blkcnt = 1,
.encrypted_page = NULL,
.is_por = !is_meta ? 1 : 0,
.is_cache = 1,
@@ -462,6 +463,7 @@ int f2fs_ra_meta_caches(struct f2fs_sb_info *sbi, block_t start,
.type = META,
.op = REQ_OP_READ,
.op_flags = sync ? (REQ_META | REQ_PRIO) : REQ_RAHEAD,
+ .folio_blkcnt = 1,
.encrypted_page = NULL,
.in_list = 0,
.is_por = (type == META_POR) ? 1 : 0,
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 747141c79900..c0e39f580993 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1282,6 +1282,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
.op_flags = wbc_to_write_flags(wbc),
.old_blkaddr = NEW_ADDR,
.page = NULL,
+ .folio_blkcnt = 1,
.encrypted_page = NULL,
.compressed_page = NULL,
.io_type = io_type,
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 6c12f58d4f9f..6b8bee06a4f3 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -850,6 +850,9 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
struct folio *fio_folio = fio->folio;
struct folio *data_folio = fio->encrypted_page ?
page_folio(fio->encrypted_page) : fio_folio;
+ pgoff_t fio_lblk = F2FS_FIO_LBLK(fio);
+ size_t bio_offset = F2FS_FIO_BIO_OFFSET(fio);
+ size_t bio_len = F2FS_FIO_BIO_SIZE(fio);
if (!f2fs_is_valid_blkaddr(fio->sbi, fio->new_blkaddr,
fio->is_por ? META_POR : (__is_meta_io(fio) ?
@@ -862,11 +865,11 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
bio = __bio_alloc(fio, 1);
f2fs_set_bio_crypt_ctx(bio, fio_folio->mapping->host,
- fio_folio->index, fio, GFP_NOIO);
- bio_add_folio_nofail(bio, data_folio, folio_size(data_folio), 0);
+ fio_lblk, fio, GFP_NOIO);
+ bio_add_folio_nofail(bio, data_folio, bio_len, bio_offset);
if (fio->io_wbc && !is_read_io(fio->op))
- wbc_account_cgroup_owner(fio->io_wbc, fio_folio, PAGE_SIZE);
+ wbc_account_cgroup_owner(fio->io_wbc, fio_folio, bio_len);
inc_cache_count(fio->sbi, is_read_io(fio->op) ?
F2FS_RD_DATA : WB_DATA_TYPE(fio->folio, false));
@@ -913,7 +916,8 @@ static bool io_is_mergeable(struct f2fs_sb_info *sbi, struct bio *bio,
}
static void add_bio_entry(struct f2fs_sb_info *sbi, struct bio *bio,
- struct folio *folio, enum temp_type temp)
+ struct folio *folio, size_t len, size_t offset,
+ enum temp_type temp)
{
struct f2fs_bio_info *io = sbi->write_io[DATA] + temp;
struct bio_entry *be;
@@ -922,7 +926,7 @@ static void add_bio_entry(struct f2fs_sb_info *sbi, struct bio *bio,
be->bio = bio;
bio_get(bio);
- bio_add_folio_nofail(bio, folio, folio_size(folio), 0);
+ bio_add_folio_nofail(bio, folio, len, offset);
f2fs_down_write(&io->bio_list_lock);
list_add_tail(&be->list, &io->bio_list);
@@ -939,6 +943,9 @@ static int add_ipu_page(struct f2fs_io_info *fio, struct bio **bio,
struct folio *folio)
{
struct folio *fio_folio = fio->folio;
+ pgoff_t fio_lblk = F2FS_FIO_LBLK(fio);
+ size_t bio_offset = F2FS_FIO_BIO_OFFSET(fio);
+ size_t bio_len = F2FS_FIO_BIO_SIZE(fio);
struct f2fs_sb_info *sbi = fio->sbi;
enum temp_type temp;
bool found = false;
@@ -961,8 +968,8 @@ static int add_ipu_page(struct f2fs_io_info *fio, struct bio **bio,
fio->new_blkaddr));
if (f2fs_crypt_mergeable_bio(*bio,
fio_folio->mapping->host,
- fio_folio->index, fio) &&
- bio_add_folio(*bio, folio, folio_size(folio), 0)) {
+ fio_lblk, fio) &&
+ bio_add_folio(*bio, folio, bio_len, bio_offset)) {
ret = 0;
break;
}
@@ -1076,6 +1083,10 @@ int f2fs_merge_page_bio(struct f2fs_io_info *fio)
struct folio *data_folio = fio->encrypted_page ?
page_folio(fio->encrypted_page) : fio->folio;
struct folio *folio = fio->folio;
+ pgoff_t fio_lblk = F2FS_FIO_LBLK(fio);
+ unsigned int fio_cnt = F2FS_FIO_BLKCNT(fio);
+ size_t bio_offset = F2FS_FIO_BIO_OFFSET(fio);
+ size_t bio_len = F2FS_FIO_BIO_SIZE(fio);
if (!f2fs_is_valid_blkaddr(fio->sbi, fio->new_blkaddr,
__is_meta_io(fio) ? META_GENERIC : DATA_GENERIC))
@@ -1090,9 +1101,10 @@ int f2fs_merge_page_bio(struct f2fs_io_info *fio)
if (!bio) {
bio = __bio_alloc(fio, BIO_MAX_VECS);
f2fs_set_bio_crypt_ctx(bio, folio->mapping->host,
- folio->index, fio, GFP_NOIO);
+ fio_lblk, fio, GFP_NOIO);
- add_bio_entry(fio->sbi, bio, data_folio, fio->temp);
+ add_bio_entry(fio->sbi, bio, data_folio, bio_len,
+ bio_offset, fio->temp);
} else {
if (add_ipu_page(fio, &bio, data_folio))
goto alloc_new;
@@ -1103,7 +1115,7 @@ int f2fs_merge_page_bio(struct f2fs_io_info *fio)
inc_cache_count(fio->sbi, WB_DATA_TYPE(folio, false));
- *fio->last_block = fio->new_blkaddr;
+ *fio->last_block = fio->new_blkaddr + fio_cnt - 1;
*fio->bio = bio;
return 0;
@@ -1166,6 +1178,10 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
struct folio *bio_folio;
struct f2fs_lock_context lc;
enum count_type type;
+ pgoff_t fio_lblk;
+ unsigned int fio_cnt;
+ size_t bio_offset;
+ size_t bio_len;
f2fs_bug_on(sbi, is_read_io(fio->op));
@@ -1198,33 +1214,39 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
/* set submitted = true as a return value */
fio->submitted = 1;
+ fio_lblk = F2FS_FIO_LBLK(fio);
+ fio_cnt = F2FS_FIO_BLKCNT(fio);
+
type = WB_DATA_TYPE(bio_folio, fio->compressed_page);
- inc_cache_count(sbi, type);
+ for (unsigned int i = 0; i < fio_cnt; i++)
+ inc_cache_count(sbi, type);
if (io->bio &&
(!io_is_mergeable(sbi, io->bio, io, fio, io->last_block_in_bio,
fio->new_blkaddr) ||
!f2fs_crypt_mergeable_bio(io->bio, fio_inode(fio),
- bio_folio->index, fio)))
+ fio_lblk, fio)))
__submit_merged_bio(io);
alloc_new:
if (io->bio == NULL) {
io->bio = __bio_alloc(fio, BIO_MAX_VECS);
f2fs_set_bio_crypt_ctx(io->bio, fio_inode(fio),
- bio_folio->index, fio, GFP_NOIO);
+ fio_lblk, fio, GFP_NOIO);
io->fio = *fio;
}
- if (!bio_add_folio(io->bio, bio_folio, folio_size(bio_folio), 0)) {
+ bio_offset = F2FS_FIO_BIO_OFFSET(fio);
+ bio_len = F2FS_FIO_BIO_SIZE(fio);
+
+ if (!bio_add_folio(io->bio, bio_folio, bio_len, bio_offset)) {
__submit_merged_bio(io);
goto alloc_new;
}
if (fio->io_wbc)
- wbc_account_cgroup_owner(fio->io_wbc, fio->folio,
- folio_size(fio->folio));
+ wbc_account_cgroup_owner(fio->io_wbc, fio->folio, bio_len);
- io->last_block_in_bio = fio->new_blkaddr;
+ io->last_block_in_bio = fio->new_blkaddr + fio_cnt - 1;
trace_f2fs_submit_folio_write(fio->folio, fio);
#ifdef CONFIG_BLK_DEV_ZONED
@@ -3200,7 +3222,8 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio)
set_new_dnode(&dn, inode, NULL, NULL, 0);
if (need_inplace_update(fio) &&
- f2fs_lookup_read_extent_cache_block(inode, folio->index,
+ f2fs_lookup_read_extent_cache_block(inode,
+ F2FS_FIO_LBLK(fio),
&fio->old_blkaddr)) {
if (!f2fs_is_valid_blkaddr(fio->sbi, fio->old_blkaddr,
DATA_GENERIC_ENHANCE))
@@ -3219,7 +3242,8 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio)
if (fio->need_lock == LOCK_REQ && !f2fs_trylock_op(fio->sbi, &lc))
return -EAGAIN;
- err = f2fs_get_dnode_of_data(&dn, folio->index, LOOKUP_NODE);
+ err = f2fs_get_dnode_of_data(&dn, F2FS_FIO_LBLK(fio),
+ LOOKUP_NODE);
if (err)
goto out;
@@ -3322,6 +3346,7 @@ int f2fs_write_single_data_page(struct folio *folio, int *submitted,
.op_flags = wbc_to_write_flags(wbc),
.old_blkaddr = NULL_ADDR,
.folio = folio,
+ .folio_blkcnt = 1,
.encrypted_page = NULL,
.submitted = 0,
.compr_blocks = compr_blocks,
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 270b1d556e45..20b7de55b2bf 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1350,6 +1350,8 @@ struct f2fs_io_info {
blk_opf_t op_flags; /* req_flag_bits */
block_t new_blkaddr; /* new block address to be written */
block_t old_blkaddr; /* old block address before Cow */
+ pgoff_t folio_offset; /* offset in large folio */
+ unsigned int folio_blkcnt; /* block count in large folio */
union {
struct page *page; /* page to be written */
struct folio *folio;
@@ -1372,6 +1374,15 @@ struct f2fs_io_info {
sector_t *last_block; /* last block number in bio */
};
+#define F2FS_FIO_LBLK(fio) \
+ (((fio)->folio)->index + (fio)->folio_offset)
+#define F2FS_FIO_BLKCNT(fio) \
+ ((fio)->folio_blkcnt)
+#define F2FS_FIO_BIO_OFFSET(fio) \
+ ((fio)->folio_offset << PAGE_SHIFT)
+#define F2FS_FIO_BIO_SIZE(fio) \
+ F2FS_BLK_TO_BYTES((fio)->sbi, F2FS_FIO_BLKCNT(fio))
+
struct bio_entry {
struct bio *bio;
struct list_head list;
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 926e6976bc22..89e50f871b75 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1228,6 +1228,7 @@ static int ra_data_block(struct inode *inode, pgoff_t index)
.temp = COLD,
.op = REQ_OP_READ,
.op_flags = 0,
+ .folio_blkcnt = 1,
.encrypted_page = NULL,
.in_list = 0,
.is_cache = 1,
@@ -1338,6 +1339,7 @@ static int move_data_block(struct inode *inode, block_t bidx,
.temp = COLD,
.op = REQ_OP_READ,
.op_flags = 0,
+ .folio_blkcnt = 1,
.encrypted_page = NULL,
.in_list = 0,
.is_cache = 1,
diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index 273b6428c9f9..ab7537ff7ebd 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -151,6 +151,7 @@ int f2fs_convert_inline_folio(struct dnode_of_data *dn, struct folio *folio)
.op = REQ_OP_WRITE,
.op_flags = REQ_SYNC | REQ_PRIO,
.folio = folio,
+ .folio_blkcnt = 1,
.encrypted_page = NULL,
.io_type = FS_DATA_IO,
};
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 794e0d99fc7c..e4b59d990ec6 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3873,7 +3873,8 @@ static int __get_segment_type_6(struct f2fs_io_info *fio)
if (file_is_cold(inode) || f2fs_need_compress_data(inode))
return CURSEG_COLD_DATA;
- type = __get_age_segment_type(inode, fio->folio->index);
+ type = __get_age_segment_type(inode,
+ F2FS_FIO_LBLK(fio));
if (type != NO_CHECK_TYPE)
return type;
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* [PATCH v3 03/17] f2fs: support regular file buffered writes on large folios
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
2026-10-09 16:12 ` [PATCH v3 01/17] f2fs: extend folio state for large folio write path Nanzhe Zhao
2026-10-09 16:12 ` [PATCH v3 02/17] f2fs: carry subpage offset and count in write IO Nanzhe Zhao
@ 2026-10-09 16:12 ` Nanzhe Zhao
2026-10-09 18:34 ` [f2fs-dev] " Daeho Jeong
2026-10-12 3:01 ` Chao Yu
2026-10-09 16:12 ` [PATCH v3 04/17] f2fs: support atomic file large folios buffered write Nanzhe Zhao
` (13 subsequent siblings)
16 siblings, 2 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:12 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
To avoid the complexity of unlocking a large folio in write_begin,
preallocate partial blocks for inodes that can use large folios.
During write_begin, read only the partial head and tail 4K subpages
that need read-before-write, and skip read I/O for the full middle
subpages covered by the write.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 369 +++++++++++++++++++++++++++++++++++++++++++++++--
fs/f2fs/f2fs.h | 1 +
fs/f2fs/file.c | 17 ++-
3 files changed, 370 insertions(+), 17 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 6b8bee06a4f3..af2bb02e301f 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -93,6 +93,20 @@ struct bio_post_read_ctx {
block_t fs_blkaddr;
};
+static bool __ffs_mark_subrange_uptodate(struct folio *folio,
+ struct f2fs_folio_state *ffs, size_t offset, size_t len)
+{
+ unsigned int nr_subpages = folio_nr_pages(folio);
+ unsigned int start, end;
+
+ start = offset >> PAGE_SHIFT;
+ end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ end = min(end, nr_subpages);
+
+ bitmap_set(ffs->state, start, end - start);
+ return bitmap_full(ffs->state, nr_subpages);
+}
+
/*
* Update and unlock a bio's pages, and free the bio.
*
@@ -107,6 +121,23 @@ struct bio_post_read_ctx {
* called (i.e., I/O error or decryption error, but *not* verity error), and
* release the bio's reference to the decompress_io_ctx of the page's cluster.
*/
+/*
+ * Update read_pages_pending.
+ */
+static inline void f2fs_update_read_folio_pending(struct folio *folio, int nr)
+{
+ struct f2fs_folio_state *ffs;
+ unsigned long flags;
+
+ if (!f2fs_folio_has_ffs(folio))
+ return;
+
+ ffs = (struct f2fs_folio_state *)folio->private;
+ spin_lock_irqsave(&ffs->state_lock, flags);
+ ffs->read_pages_pending += nr;
+ spin_unlock_irqrestore(&ffs->state_lock, flags);
+}
+
static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
{
struct folio_iter fi;
@@ -128,7 +159,8 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
}
if (folio_test_large(folio)) {
- struct f2fs_folio_state *ffs = folio->private;
+ struct f2fs_folio_state *ffs =
+ (struct f2fs_folio_state *)folio->private;
spin_lock_irqsave(&ffs->state_lock, flags);
ffs->read_pages_pending -= nr_pages;
@@ -1430,6 +1462,36 @@ static void f2fs_submit_page_read(struct inode *inode, struct fsverity_info *vi,
f2fs_submit_read_bio(sbi, bio, DATA);
}
+/*
+ * Synchronously read a single 4K subpage by reusing f2fs_submit_page_read()
+ * so that iostat, trace, blk-crypto and post-read handling are all preserved.
+ * The caller must have already allocated ffs for the folio.
+ */
+static int f2fs_submit_page_read_sync(struct inode *inode, struct folio *folio,
+ pgoff_t index, block_t blkaddr)
+{
+ struct f2fs_folio_state *ffs =
+ (struct f2fs_folio_state *)folio->private;
+
+ /* Add bias so end_io does not call folio_end_read(). */
+ f2fs_update_read_folio_pending(folio, 1);
+
+ f2fs_submit_page_read(inode, NULL, folio, index, blkaddr,
+ REQ_OP_READ, false);
+
+ /* Wait until all bios have completed (pending drops back to our bias). */
+ while (READ_ONCE(ffs->read_pages_pending) != 1)
+ f2fs_io_schedule_timeout(DEFAULT_SCHEDULE_TIMEOUT);
+
+ /* Remove the bias. */
+ f2fs_update_read_folio_pending(folio, -1);
+
+ if (!f2fs_ffs_test_blk_uptodate(folio, index))
+ return -EIO;
+
+ return 0;
+}
+
static void __set_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
{
__le32 *addr = get_dnode_addr(dn->inode, dn->node_entry);
@@ -2767,6 +2829,110 @@ static void ffs_detach_free(struct folio *folio)
kfree(ffs);
}
+bool f2fs_ffs_test_blk_uptodate(const struct folio *folio, pgoff_t index)
+{
+ struct f2fs_folio_state *ffs;
+ unsigned int idx;
+
+ f2fs_bug_on(F2FS_F_SB(folio), !folio_contains(folio, index));
+
+ if (folio_test_uptodate(folio))
+ return true;
+
+ if (!f2fs_folio_has_ffs(folio))
+ return false;
+
+ ffs = (struct f2fs_folio_state *)folio->private;
+ idx = index - folio->index;
+ return test_bit(idx, ffs->state);
+}
+
+static void f2fs_ffs_mark_subrange_uptodate(struct folio *folio, size_t offset,
+ size_t len)
+{
+ struct f2fs_folio_state *ffs;
+ unsigned long flags;
+ bool mark_uptodate = false;
+
+ f2fs_bug_on(F2FS_F_SB(folio), offset + len > folio_size(folio));
+
+ if (!f2fs_folio_has_ffs(folio)) {
+ folio_mark_uptodate(folio);
+ return;
+ }
+
+ ffs = (struct f2fs_folio_state *)folio->private;
+ spin_lock_irqsave(&ffs->state_lock, flags);
+ mark_uptodate = __ffs_mark_subrange_uptodate(folio, ffs, offset, len) &&
+ !ffs->read_pages_pending;
+ spin_unlock_irqrestore(&ffs->state_lock, flags);
+ if (mark_uptodate)
+ folio_mark_uptodate(folio);
+}
+
+static unsigned int __ffs_mark_subrange_dirty(struct folio *folio,
+ struct f2fs_folio_state *ffs, size_t offset, size_t len)
+{
+ unsigned int nr_subpages = folio_nr_pages(folio);
+ unsigned int start, end, before;
+
+ start = offset >> PAGE_SHIFT;
+ end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ end = min(end, nr_subpages);
+
+ before = bitmap_weight(ffs->state, 2 * nr_subpages);
+ bitmap_set(ffs->state, nr_subpages + start, end - start);
+ return bitmap_weight(ffs->state, 2 * nr_subpages) - before;
+}
+
+static void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
+ size_t offset, size_t len)
+{
+ struct f2fs_folio_state *ffs;
+ unsigned long flags;
+
+ f2fs_bug_on(F2FS_F_SB(folio), offset + len > folio_size(folio));
+
+ if (!f2fs_folio_has_ffs(folio))
+ return;
+
+ ffs = (struct f2fs_folio_state *)folio->private;
+
+ spin_lock_irqsave(&ffs->state_lock, flags);
+ __ffs_mark_subrange_dirty(folio, ffs, offset, len);
+ spin_unlock_irqrestore(&ffs->state_lock, flags);
+}
+
+static bool find_next_valid_block(const struct folio *folio,
+ size_t orig_off, size_t *need_off,
+ size_t len)
+{
+ size_t start = orig_off;
+ size_t end = start + len;
+ size_t head, tail;
+ pgoff_t index;
+
+ if (start & (PAGE_SIZE - 1)) {
+ head = round_down(start, PAGE_SIZE);
+ index = folio->index + (head >> PAGE_SHIFT);
+ if (!f2fs_ffs_test_blk_uptodate(folio, index)) {
+ *need_off = head;
+ return true;
+ }
+ }
+
+ if (end & (PAGE_SIZE - 1)) {
+ tail = round_down(end, PAGE_SIZE);
+ index = folio->index + (tail >> PAGE_SHIFT);
+ if (!f2fs_ffs_test_blk_uptodate(folio, index)) {
+ *need_off = tail;
+ return true;
+ }
+ }
+
+ return false;
+}
+
static int f2fs_read_data_large_folio(struct inode *inode,
struct fsverity_info *vi,
struct readahead_control *rac, struct folio *folio)
@@ -4128,6 +4294,135 @@ static int prepare_atomic_write_begin(struct f2fs_sb_info *sbi,
return 0;
}
+/*
+ * Drop the folio lock when a node was changed, then balance the
+ * filesystem and reacquire the lock.
+ *
+ * Return: true if the folio became unusable while unlocked (being
+ * truncated), false if the folio is still usable.
+ */
+static bool f2fs_folio_may_unlock_balance_fs(struct folio *folio,
+ struct address_space *mapping, bool node_changed)
+{
+ struct inode *inode = folio->mapping->host;
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ unsigned int orig_order;
+
+ if (!node_changed || IS_NOQUOTA(inode) ||
+ !has_not_enough_free_secs(sbi, 0, 0))
+ return false;
+
+ orig_order = folio_order(folio);
+ folio_unlock(folio);
+ f2fs_balance_fs(sbi, true);
+ folio_lock(folio);
+
+ if (folio->mapping != mapping)
+ return true;
+
+ if (folio_order(folio) != orig_order)
+ return true;
+
+ return false;
+}
+
+static int prepare_large_folio_write_begin(struct inode *inode,
+ struct folio *folio, loff_t pos,
+ unsigned int len)
+{
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ struct f2fs_folio_state *ffs;
+ size_t ori_off = offset_in_folio(folio, pos);
+ size_t need_off = ori_off;
+ int err = 0;
+
+ /*
+ * when the write did not come through f2fs_write_iter, we preallocate all
+ * blocks in the write range here.
+ */
+ if (!is_inode_flag_set(inode, FI_PREALLOCATED_ALL) &&
+ !IS_DEVICE_ALIASING(inode)) {
+ pgoff_t first = F2FS_BYTES_TO_BLK(sbi, pos);
+ pgoff_t last = F2FS_BLK_ALIGN(sbi, pos + len);
+ pgoff_t idx;
+
+ for (idx = first; idx < last; idx++) {
+ block_t blkaddr = NULL_ADDR;
+ bool node_changed = false;
+
+ err = __reserve_data_block(inode, idx, &blkaddr,
+ &node_changed);
+ if (err)
+ return err;
+ if (f2fs_folio_may_unlock_balance_fs(folio, folio->mapping,
+ node_changed))
+ return -EAGAIN;
+ }
+ }
+
+ ffs = f2fs_ffs_find_or_alloc(folio);
+ if (!ffs)
+ return -ENOMEM;
+
+ /* Skip read if the folio is already fully uptodate or the write
+ * covers the entire folio.
+ */
+ if (folio_test_uptodate(folio) || len == folio_size(folio))
+ return 0;
+
+ if (!f2fs_verity_in_progress(inode) &&
+ !(pos & (PAGE_SIZE - 1)) && (pos + len) >= i_size_read(inode)) {
+ size_t zoff = ori_off + len;
+
+ if (zoff < folio_size(folio))
+ folio_zero_segment(folio, zoff, folio_size(folio));
+ return 0;
+ }
+
+ /* Inline data must have been converted before reaching here. */
+ f2fs_bug_on(sbi, f2fs_has_inline_data(inode));
+
+ while (find_next_valid_block(folio, ori_off,
+ &need_off, len)) {
+ struct dnode_of_data dn;
+ pgoff_t index = folio->index + (need_off >> PAGE_SHIFT);
+ block_t blkaddr;
+
+ if (!f2fs_lookup_read_extent_cache_block(inode, index,
+ &blkaddr)) {
+ if (IS_DEVICE_ALIASING(inode))
+ return -ENODATA;
+
+ set_new_dnode(&dn, inode, NULL, NULL, 0);
+ err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
+ if (err)
+ return err;
+ blkaddr = dn.data_blkaddr;
+ f2fs_put_dnode(&dn);
+
+ if (blkaddr == NEW_ADDR) {
+ size_t off = offset_in_folio(folio,
+ index << PAGE_SHIFT);
+
+ folio_zero_segment(folio, off, off + PAGE_SIZE);
+ f2fs_ffs_mark_subrange_uptodate(folio, off,
+ PAGE_SIZE);
+ continue;
+ }
+
+ if (!f2fs_is_valid_blkaddr(sbi, blkaddr,
+ DATA_GENERIC_ENHANCE_READ))
+ return -EFSCORRUPTED;
+ }
+
+ err = f2fs_submit_page_read_sync(inode, folio, index, blkaddr);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
static int f2fs_write_begin(const struct kiocb *iocb,
struct address_space *mapping,
loff_t pos, unsigned len, struct folio **foliop,
@@ -4139,6 +4434,8 @@ static int f2fs_write_begin(const struct kiocb *iocb,
pgoff_t index = pos >> PAGE_SHIFT;
bool need_balance = false;
block_t blkaddr = NULL_ADDR;
+ fgf_t fgp = FGP_LOCK | FGP_WRITE | FGP_CREAT;
+ unsigned int blen;
int err = 0;
trace_f2fs_write_begin(inode, pos, len);
@@ -4186,9 +4483,15 @@ static int f2fs_write_begin(const struct kiocb *iocb,
* Do not use FGP_STABLE to avoid deadlock.
* Will wait that below with our IO control.
*/
- folio = f2fs_filemap_get_folio(mapping, index,
- FGP_LOCK | FGP_WRITE | FGP_CREAT,
- mapping_gfp_mask(mapping));
+ /*
+ * Inline data is carried in the first subpage. Keep the index #0
+ * folio order-0 so that the existing inline read/convert paths
+ * (prepare_write_begin()) still apply; large folios are used from
+ * the second folio on.
+ */
+ fgp |= fgf_set_order(f2fs_has_inline_data(inode) ? PAGE_SIZE : len);
+ folio = f2fs_filemap_get_folio(mapping, index, fgp,
+ mapping_gfp_mask(mapping));
if (IS_ERR(folio)) {
err = PTR_ERR(folio);
goto fail;
@@ -4198,11 +4501,15 @@ static int f2fs_write_begin(const struct kiocb *iocb,
*foliop = folio;
+ /* Clamp the write length to the folio size. */
+ blen = min_t(unsigned int, len,
+ folio_size(folio) - offset_in_folio(folio, pos));
+
if (f2fs_is_atomic_file(inode))
err = prepare_atomic_write_begin(sbi, folio, pos, len,
&blkaddr, &need_balance);
- else
- err = prepare_write_begin(sbi, folio, pos, len,
+ else if (!folio_test_large(folio))
+ err = prepare_write_begin(sbi, folio, pos, blen,
&blkaddr, &need_balance);
if (err)
goto put_folio;
@@ -4222,7 +4529,19 @@ static int f2fs_write_begin(const struct kiocb *iocb,
f2fs_folio_wait_writeback(folio, false, true);
- if (len == folio_size(folio) || folio_test_uptodate(folio))
+ if (folio_test_large(folio)) {
+ err = prepare_large_folio_write_begin(inode,
+ folio, pos, blen);
+ if (!err)
+ return 0;
+ if (err == -EAGAIN) {
+ f2fs_folio_put(folio, true);
+ goto repeat;
+ }
+ goto put_folio;
+ }
+
+ if (blen == folio_size(folio) || folio_test_uptodate(folio))
return 0;
if (!(pos & (PAGE_SIZE - 1)) && (pos + len) >= i_size_read(inode) &&
@@ -4282,15 +4601,20 @@ static int f2fs_write_end(const struct kiocb *iocb,
trace_f2fs_write_end(inode, pos, len, copied);
/*
- * This should be come from len == PAGE_SIZE, and we expect copied
- * should be PAGE_SIZE. Otherwise, we treat it with zero copied and
- * let generic_perform_write() try to copy data again through copied=0.
+ * If a short copy happens on a folio that isn't uptodate, we treat
+ * it with zero copied and let generic_perform_write() try to copy
+ * data again through copied=0.
*/
if (!folio_test_uptodate(folio)) {
- if (unlikely(copied != len))
+ if (unlikely(copied != len)) {
copied = 0;
- else
+ } else if (folio_test_large(folio)) {
+ f2fs_ffs_mark_subrange_uptodate(folio,
+ offset_in_folio(folio, pos), len);
+ } else {
+ /* This should be come from len == PAGE_SIZE */
folio_mark_uptodate(folio);
+ }
}
#ifdef CONFIG_F2FS_FS_COMPRESSION
@@ -4309,6 +4633,9 @@ static int f2fs_write_end(const struct kiocb *iocb,
if (!copied)
goto unlock_out;
+ if (folio_test_large(folio))
+ f2fs_ffs_mark_subrange_dirty(folio, offset_in_folio(folio, pos),
+ copied);
folio_mark_dirty(folio);
if (f2fs_is_atomic_file(inode))
@@ -4365,8 +4692,22 @@ static bool f2fs_dirty_data_folio(struct address_space *mapping,
trace_f2fs_set_page_dirty(folio, DATA);
- if (!folio_test_uptodate(folio))
- folio_mark_uptodate(folio);
+ if (!folio_test_uptodate(folio)) {
+ bool uptodate = true;
+
+ if (f2fs_folio_has_ffs(folio)) {
+ struct f2fs_folio_state *ffs =
+ (struct f2fs_folio_state *)folio->private;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ffs->state_lock, flags);
+ uptodate = bitmap_full(ffs->state, folio_nr_pages(folio)) &&
+ !ffs->read_pages_pending;
+ spin_unlock_irqrestore(&ffs->state_lock, flags);
+ }
+ if (uptodate)
+ folio_mark_uptodate(folio);
+ }
BUG_ON(folio_test_swapcache(folio));
if (filemap_dirty_folio(mapping, folio)) {
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 20b7de55b2bf..e14275f98fe7 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4450,6 +4450,7 @@ int f2fs_write_single_data_page(struct folio *folio, int *submitted,
struct writeback_control *wbc,
enum iostat_type io_type,
int compr_blocks, bool allow_balance);
+bool f2fs_ffs_test_blk_uptodate(const struct folio *folio, pgoff_t index);
void f2fs_write_failed(struct inode *inode, loff_t to);
void f2fs_invalidate_folio(struct folio *folio, size_t offset, size_t length);
bool f2fs_release_folio(struct folio *folio, gfp_t wait);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ef4d218e694b..aade9a04d8f3 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -5408,9 +5408,20 @@ static int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *iter,
return ret;
}
- /* Do not preallocate blocks that will be written partially in 4KB. */
- map.m_lblk = F2FS_BLK_ALIGN(sbi, pos);
- map.m_len = F2FS_BYTES_TO_BLK(sbi, pos + count);
+ if (!dio && mapping_large_folio_support(inode->i_mapping)) {
+ /*
+ * Preallocate all blocks touched by a large-folio buffered write so
+ * the regular write_begin path does not need to unlock the folio for
+ * f2fs_balance_fs(). Rechecking large-folio state after unlock is
+ * unreliable since partial truncation can split the folio.
+ */
+ map.m_lblk = F2FS_BYTES_TO_BLK(sbi, pos);
+ map.m_len = F2FS_BLK_ALIGN(sbi, pos + count);
+ } else {
+ /* Do not preallocate blocks that will be written partially in 4KB. */
+ map.m_lblk = F2FS_BLK_ALIGN(sbi, pos);
+ map.m_len = F2FS_BYTES_TO_BLK(sbi, pos + count);
+ }
if (map.m_len > map.m_lblk)
map.m_len -= map.m_lblk;
else
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [f2fs-dev] [PATCH v3 03/17] f2fs: support regular file buffered writes on large folios
2026-10-09 16:12 ` [PATCH v3 03/17] f2fs: support regular file buffered writes on large folios Nanzhe Zhao
@ 2026-10-09 18:34 ` Daeho Jeong
2026-10-10 10:02 ` Nanzhe Zhao
2026-10-12 3:01 ` Chao Yu
1 sibling, 1 reply; 29+ messages in thread
From: Daeho Jeong @ 2026-10-09 18:34 UTC (permalink / raw)
To: Nanzhe Zhao
Cc: linux-f2fs-devel, Jaegeuk Kim, Chao Yu, Barry Song, Juan Yescas,
Daeho Jeong, Dev Jain, David Hildenbrand, linux-kernel, Bo Zhang,
Kalesh Singh, Nanzhe Zhao, Pengfei Li, Ryan Roberts
On Fri, Oct 9, 2026 at 9:15 AM Nanzhe Zhao via Linux-f2fs-devel
<linux-f2fs-devel@lists.sourceforge.net> wrote:
>
> To avoid the complexity of unlocking a large folio in write_begin,
> preallocate partial blocks for inodes that can use large folios.
> During write_begin, read only the partial head and tail 4K subpages
> that need read-before-write, and skip read I/O for the full middle
> subpages covered by the write.
>
> Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
> ---
> fs/f2fs/data.c | 369 +++++++++++++++++++++++++++++++++++++++++++++++--
> fs/f2fs/f2fs.h | 1 +
> fs/f2fs/file.c | 17 ++-
> 3 files changed, 370 insertions(+), 17 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 6b8bee06a4f3..af2bb02e301f 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -93,6 +93,20 @@ struct bio_post_read_ctx {
> block_t fs_blkaddr;
> };
>
> +static bool __ffs_mark_subrange_uptodate(struct folio *folio,
> + struct f2fs_folio_state *ffs, size_t offset, size_t len)
> +{
> + unsigned int nr_subpages = folio_nr_pages(folio);
> + unsigned int start, end;
> +
> + start = offset >> PAGE_SHIFT;
> + end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
> + end = min(end, nr_subpages);
> +
> + bitmap_set(ffs->state, start, end - start);
> + return bitmap_full(ffs->state, nr_subpages);
> +}
> +
> /*
> * Update and unlock a bio's pages, and free the bio.
> *
> @@ -107,6 +121,23 @@ struct bio_post_read_ctx {
> * called (i.e., I/O error or decryption error, but *not* verity error), and
> * release the bio's reference to the decompress_io_ctx of the page's cluster.
> */
> +/*
> + * Update read_pages_pending.
> + */
> +static inline void f2fs_update_read_folio_pending(struct folio *folio, int nr)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned long flags;
> +
> + if (!f2fs_folio_has_ffs(folio))
> + return;
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> + spin_lock_irqsave(&ffs->state_lock, flags);
> + ffs->read_pages_pending += nr;
> + spin_unlock_irqrestore(&ffs->state_lock, flags);
> +}
> +
> static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
> {
> struct folio_iter fi;
> @@ -128,7 +159,8 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
> }
>
> if (folio_test_large(folio)) {
> - struct f2fs_folio_state *ffs = folio->private;
> + struct f2fs_folio_state *ffs =
> + (struct f2fs_folio_state *)folio->private;
>
> spin_lock_irqsave(&ffs->state_lock, flags);
> ffs->read_pages_pending -= nr_pages;
> @@ -1430,6 +1462,36 @@ static void f2fs_submit_page_read(struct inode *inode, struct fsverity_info *vi,
> f2fs_submit_read_bio(sbi, bio, DATA);
> }
>
> +/*
> + * Synchronously read a single 4K subpage by reusing f2fs_submit_page_read()
> + * so that iostat, trace, blk-crypto and post-read handling are all preserved.
> + * The caller must have already allocated ffs for the folio.
> + */
> +static int f2fs_submit_page_read_sync(struct inode *inode, struct folio *folio,
> + pgoff_t index, block_t blkaddr)
> +{
> + struct f2fs_folio_state *ffs =
> + (struct f2fs_folio_state *)folio->private;
> +
> + /* Add bias so end_io does not call folio_end_read(). */
> + f2fs_update_read_folio_pending(folio, 1);
> +
> + f2fs_submit_page_read(inode, NULL, folio, index, blkaddr,
> + REQ_OP_READ, false);
> +
> + /* Wait until all bios have completed (pending drops back to our bias). */
> + while (READ_ONCE(ffs->read_pages_pending) != 1)
> + f2fs_io_schedule_timeout(DEFAULT_SCHEDULE_TIMEOUT);
> +
> + /* Remove the bias. */
> + f2fs_update_read_folio_pending(folio, -1);
> +
> + if (!f2fs_ffs_test_blk_uptodate(folio, index))
> + return -EIO;
> +
> + return 0;
> +}
> +
> static void __set_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
> {
> __le32 *addr = get_dnode_addr(dn->inode, dn->node_entry);
> @@ -2767,6 +2829,110 @@ static void ffs_detach_free(struct folio *folio)
> kfree(ffs);
> }
>
> +bool f2fs_ffs_test_blk_uptodate(const struct folio *folio, pgoff_t index)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned int idx;
> +
> + f2fs_bug_on(F2FS_F_SB(folio), !folio_contains(folio, index));
> +
> + if (folio_test_uptodate(folio))
> + return true;
> +
> + if (!f2fs_folio_has_ffs(folio))
> + return false;
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> + idx = index - folio->index;
> + return test_bit(idx, ffs->state);
> +}
> +
> +static void f2fs_ffs_mark_subrange_uptodate(struct folio *folio, size_t offset,
> + size_t len)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned long flags;
> + bool mark_uptodate = false;
> +
> + f2fs_bug_on(F2FS_F_SB(folio), offset + len > folio_size(folio));
> +
> + if (!f2fs_folio_has_ffs(folio)) {
> + folio_mark_uptodate(folio);
> + return;
> + }
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> + spin_lock_irqsave(&ffs->state_lock, flags);
> + mark_uptodate = __ffs_mark_subrange_uptodate(folio, ffs, offset, len) &&
> + !ffs->read_pages_pending;
> + spin_unlock_irqrestore(&ffs->state_lock, flags);
> + if (mark_uptodate)
> + folio_mark_uptodate(folio);
> +}
> +
> +static unsigned int __ffs_mark_subrange_dirty(struct folio *folio,
> + struct f2fs_folio_state *ffs, size_t offset, size_t len)
> +{
> + unsigned int nr_subpages = folio_nr_pages(folio);
> + unsigned int start, end, before;
> +
> + start = offset >> PAGE_SHIFT;
> + end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
> + end = min(end, nr_subpages);
> +
> + before = bitmap_weight(ffs->state, 2 * nr_subpages);
> + bitmap_set(ffs->state, nr_subpages + start, end - start);
> + return bitmap_weight(ffs->state, 2 * nr_subpages) - before;
> +}
> +
> +static void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
> + size_t offset, size_t len)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned long flags;
> +
> + f2fs_bug_on(F2FS_F_SB(folio), offset + len > folio_size(folio));
> +
> + if (!f2fs_folio_has_ffs(folio))
> + return;
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> +
> + spin_lock_irqsave(&ffs->state_lock, flags);
> + __ffs_mark_subrange_dirty(folio, ffs, offset, len);
> + spin_unlock_irqrestore(&ffs->state_lock, flags);
> +}
> +
> +static bool find_next_valid_block(const struct folio *folio,
> + size_t orig_off, size_t *need_off,
> + size_t len)
> +{
> + size_t start = orig_off;
> + size_t end = start + len;
> + size_t head, tail;
> + pgoff_t index;
> +
> + if (start & (PAGE_SIZE - 1)) {
> + head = round_down(start, PAGE_SIZE);
> + index = folio->index + (head >> PAGE_SHIFT);
> + if (!f2fs_ffs_test_blk_uptodate(folio, index)) {
> + *need_off = head;
> + return true;
> + }
> + }
> +
> + if (end & (PAGE_SIZE - 1)) {
> + tail = round_down(end, PAGE_SIZE);
> + index = folio->index + (tail >> PAGE_SHIFT);
> + if (!f2fs_ffs_test_blk_uptodate(folio, index)) {
> + *need_off = tail;
> + return true;
> + }
> + }
> +
> + return false;
> +}
> +
> static int f2fs_read_data_large_folio(struct inode *inode,
> struct fsverity_info *vi,
> struct readahead_control *rac, struct folio *folio)
> @@ -4128,6 +4294,135 @@ static int prepare_atomic_write_begin(struct f2fs_sb_info *sbi,
> return 0;
> }
>
> +/*
> + * Drop the folio lock when a node was changed, then balance the
> + * filesystem and reacquire the lock.
> + *
> + * Return: true if the folio became unusable while unlocked (being
> + * truncated), false if the folio is still usable.
> + */
> +static bool f2fs_folio_may_unlock_balance_fs(struct folio *folio,
> + struct address_space *mapping, bool node_changed)
> +{
> + struct inode *inode = folio->mapping->host;
> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> + unsigned int orig_order;
> +
> + if (!node_changed || IS_NOQUOTA(inode) ||
> + !has_not_enough_free_secs(sbi, 0, 0))
> + return false;
> +
> + orig_order = folio_order(folio);
> + folio_unlock(folio);
> + f2fs_balance_fs(sbi, true);
> + folio_lock(folio);
Hi Nanzhe,
Thanks for reworking this. One thing about where it is called.
In f2fs_write_begin(), the order-0 path balances before
f2fs_folio_wait_writeback(), but prepare_large_folio_write_begin() and
prepare_large_folio_atomic_write_begin() (04/17) are called after it,
so their f2fs_folio_may_unlock_balance_fs() calls unlock the folio
after the wait. If the folio already has dirty blocks, writeback can
start on it while it is unlocked, and nothing waits again after
folio_lock(), so the new data can be copied into a folio under
writeback.
Maybe f2fs_folio_may_unlock_balance_fs() could call
f2fs_folio_wait_writeback() after relocking?
Thanks,
Daeho
> +
> + if (folio->mapping != mapping)
> + return true;
> +
> + if (folio_order(folio) != orig_order)
> + return true;
> +
> + return false;
> +}
> +
> +static int prepare_large_folio_write_begin(struct inode *inode,
> + struct folio *folio, loff_t pos,
> + unsigned int len)
> +{
> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> + struct f2fs_folio_state *ffs;
> + size_t ori_off = offset_in_folio(folio, pos);
> + size_t need_off = ori_off;
> + int err = 0;
> +
> + /*
> + * when the write did not come through f2fs_write_iter, we preallocate all
> + * blocks in the write range here.
> + */
> + if (!is_inode_flag_set(inode, FI_PREALLOCATED_ALL) &&
> + !IS_DEVICE_ALIASING(inode)) {
> + pgoff_t first = F2FS_BYTES_TO_BLK(sbi, pos);
> + pgoff_t last = F2FS_BLK_ALIGN(sbi, pos + len);
> + pgoff_t idx;
> +
> + for (idx = first; idx < last; idx++) {
> + block_t blkaddr = NULL_ADDR;
> + bool node_changed = false;
> +
> + err = __reserve_data_block(inode, idx, &blkaddr,
> + &node_changed);
> + if (err)
> + return err;
> + if (f2fs_folio_may_unlock_balance_fs(folio, folio->mapping,
> + node_changed))
> + return -EAGAIN;
> + }
> + }
> +
> + ffs = f2fs_ffs_find_or_alloc(folio);
> + if (!ffs)
> + return -ENOMEM;
> +
> + /* Skip read if the folio is already fully uptodate or the write
> + * covers the entire folio.
> + */
> + if (folio_test_uptodate(folio) || len == folio_size(folio))
> + return 0;
> +
> + if (!f2fs_verity_in_progress(inode) &&
> + !(pos & (PAGE_SIZE - 1)) && (pos + len) >= i_size_read(inode)) {
> + size_t zoff = ori_off + len;
> +
> + if (zoff < folio_size(folio))
> + folio_zero_segment(folio, zoff, folio_size(folio));
> + return 0;
> + }
> +
> + /* Inline data must have been converted before reaching here. */
> + f2fs_bug_on(sbi, f2fs_has_inline_data(inode));
> +
> + while (find_next_valid_block(folio, ori_off,
> + &need_off, len)) {
> + struct dnode_of_data dn;
> + pgoff_t index = folio->index + (need_off >> PAGE_SHIFT);
> + block_t blkaddr;
> +
> + if (!f2fs_lookup_read_extent_cache_block(inode, index,
> + &blkaddr)) {
> + if (IS_DEVICE_ALIASING(inode))
> + return -ENODATA;
> +
> + set_new_dnode(&dn, inode, NULL, NULL, 0);
> + err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
> + if (err)
> + return err;
> + blkaddr = dn.data_blkaddr;
> + f2fs_put_dnode(&dn);
> +
> + if (blkaddr == NEW_ADDR) {
> + size_t off = offset_in_folio(folio,
> + index << PAGE_SHIFT);
> +
> + folio_zero_segment(folio, off, off + PAGE_SIZE);
> + f2fs_ffs_mark_subrange_uptodate(folio, off,
> + PAGE_SIZE);
> + continue;
> + }
> +
> + if (!f2fs_is_valid_blkaddr(sbi, blkaddr,
> + DATA_GENERIC_ENHANCE_READ))
> + return -EFSCORRUPTED;
> + }
> +
> + err = f2fs_submit_page_read_sync(inode, folio, index, blkaddr);
> + if (err)
> + return err;
> + }
> +
> + return 0;
> +}
> +
> static int f2fs_write_begin(const struct kiocb *iocb,
> struct address_space *mapping,
> loff_t pos, unsigned len, struct folio **foliop,
> @@ -4139,6 +4434,8 @@ static int f2fs_write_begin(const struct kiocb *iocb,
> pgoff_t index = pos >> PAGE_SHIFT;
> bool need_balance = false;
> block_t blkaddr = NULL_ADDR;
> + fgf_t fgp = FGP_LOCK | FGP_WRITE | FGP_CREAT;
> + unsigned int blen;
> int err = 0;
>
> trace_f2fs_write_begin(inode, pos, len);
> @@ -4186,9 +4483,15 @@ static int f2fs_write_begin(const struct kiocb *iocb,
> * Do not use FGP_STABLE to avoid deadlock.
> * Will wait that below with our IO control.
> */
> - folio = f2fs_filemap_get_folio(mapping, index,
> - FGP_LOCK | FGP_WRITE | FGP_CREAT,
> - mapping_gfp_mask(mapping));
> + /*
> + * Inline data is carried in the first subpage. Keep the index #0
> + * folio order-0 so that the existing inline read/convert paths
> + * (prepare_write_begin()) still apply; large folios are used from
> + * the second folio on.
> + */
> + fgp |= fgf_set_order(f2fs_has_inline_data(inode) ? PAGE_SIZE : len);
> + folio = f2fs_filemap_get_folio(mapping, index, fgp,
> + mapping_gfp_mask(mapping));
> if (IS_ERR(folio)) {
> err = PTR_ERR(folio);
> goto fail;
> @@ -4198,11 +4501,15 @@ static int f2fs_write_begin(const struct kiocb *iocb,
>
> *foliop = folio;
>
> + /* Clamp the write length to the folio size. */
> + blen = min_t(unsigned int, len,
> + folio_size(folio) - offset_in_folio(folio, pos));
> +
> if (f2fs_is_atomic_file(inode))
> err = prepare_atomic_write_begin(sbi, folio, pos, len,
> &blkaddr, &need_balance);
> - else
> - err = prepare_write_begin(sbi, folio, pos, len,
> + else if (!folio_test_large(folio))
> + err = prepare_write_begin(sbi, folio, pos, blen,
> &blkaddr, &need_balance);
> if (err)
> goto put_folio;
> @@ -4222,7 +4529,19 @@ static int f2fs_write_begin(const struct kiocb *iocb,
>
> f2fs_folio_wait_writeback(folio, false, true);
>
> - if (len == folio_size(folio) || folio_test_uptodate(folio))
> + if (folio_test_large(folio)) {
> + err = prepare_large_folio_write_begin(inode,
> + folio, pos, blen);
> + if (!err)
> + return 0;
> + if (err == -EAGAIN) {
> + f2fs_folio_put(folio, true);
> + goto repeat;
> + }
> + goto put_folio;
> + }
> +
> + if (blen == folio_size(folio) || folio_test_uptodate(folio))
> return 0;
>
> if (!(pos & (PAGE_SIZE - 1)) && (pos + len) >= i_size_read(inode) &&
> @@ -4282,15 +4601,20 @@ static int f2fs_write_end(const struct kiocb *iocb,
> trace_f2fs_write_end(inode, pos, len, copied);
>
> /*
> - * This should be come from len == PAGE_SIZE, and we expect copied
> - * should be PAGE_SIZE. Otherwise, we treat it with zero copied and
> - * let generic_perform_write() try to copy data again through copied=0.
> + * If a short copy happens on a folio that isn't uptodate, we treat
> + * it with zero copied and let generic_perform_write() try to copy
> + * data again through copied=0.
> */
> if (!folio_test_uptodate(folio)) {
> - if (unlikely(copied != len))
> + if (unlikely(copied != len)) {
> copied = 0;
> - else
> + } else if (folio_test_large(folio)) {
> + f2fs_ffs_mark_subrange_uptodate(folio,
> + offset_in_folio(folio, pos), len);
> + } else {
> + /* This should be come from len == PAGE_SIZE */
> folio_mark_uptodate(folio);
> + }
> }
>
> #ifdef CONFIG_F2FS_FS_COMPRESSION
> @@ -4309,6 +4633,9 @@ static int f2fs_write_end(const struct kiocb *iocb,
> if (!copied)
> goto unlock_out;
>
> + if (folio_test_large(folio))
> + f2fs_ffs_mark_subrange_dirty(folio, offset_in_folio(folio, pos),
> + copied);
> folio_mark_dirty(folio);
>
> if (f2fs_is_atomic_file(inode))
> @@ -4365,8 +4692,22 @@ static bool f2fs_dirty_data_folio(struct address_space *mapping,
>
> trace_f2fs_set_page_dirty(folio, DATA);
>
> - if (!folio_test_uptodate(folio))
> - folio_mark_uptodate(folio);
> + if (!folio_test_uptodate(folio)) {
> + bool uptodate = true;
> +
> + if (f2fs_folio_has_ffs(folio)) {
> + struct f2fs_folio_state *ffs =
> + (struct f2fs_folio_state *)folio->private;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&ffs->state_lock, flags);
> + uptodate = bitmap_full(ffs->state, folio_nr_pages(folio)) &&
> + !ffs->read_pages_pending;
> + spin_unlock_irqrestore(&ffs->state_lock, flags);
> + }
> + if (uptodate)
> + folio_mark_uptodate(folio);
> + }
> BUG_ON(folio_test_swapcache(folio));
>
> if (filemap_dirty_folio(mapping, folio)) {
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 20b7de55b2bf..e14275f98fe7 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -4450,6 +4450,7 @@ int f2fs_write_single_data_page(struct folio *folio, int *submitted,
> struct writeback_control *wbc,
> enum iostat_type io_type,
> int compr_blocks, bool allow_balance);
> +bool f2fs_ffs_test_blk_uptodate(const struct folio *folio, pgoff_t index);
> void f2fs_write_failed(struct inode *inode, loff_t to);
> void f2fs_invalidate_folio(struct folio *folio, size_t offset, size_t length);
> bool f2fs_release_folio(struct folio *folio, gfp_t wait);
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index ef4d218e694b..aade9a04d8f3 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -5408,9 +5408,20 @@ static int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *iter,
> return ret;
> }
>
> - /* Do not preallocate blocks that will be written partially in 4KB. */
> - map.m_lblk = F2FS_BLK_ALIGN(sbi, pos);
> - map.m_len = F2FS_BYTES_TO_BLK(sbi, pos + count);
> + if (!dio && mapping_large_folio_support(inode->i_mapping)) {
> + /*
> + * Preallocate all blocks touched by a large-folio buffered write so
> + * the regular write_begin path does not need to unlock the folio for
> + * f2fs_balance_fs(). Rechecking large-folio state after unlock is
> + * unreliable since partial truncation can split the folio.
> + */
> + map.m_lblk = F2FS_BYTES_TO_BLK(sbi, pos);
> + map.m_len = F2FS_BLK_ALIGN(sbi, pos + count);
> + } else {
> + /* Do not preallocate blocks that will be written partially in 4KB. */
> + map.m_lblk = F2FS_BLK_ALIGN(sbi, pos);
> + map.m_len = F2FS_BYTES_TO_BLK(sbi, pos + count);
> + }
> if (map.m_len > map.m_lblk)
> map.m_len -= map.m_lblk;
> else
> --
> 2.43.0
>
>
>
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [f2fs-dev] [PATCH v3 03/17] f2fs: support regular file buffered writes on large folios
2026-10-09 18:34 ` [f2fs-dev] " Daeho Jeong
@ 2026-10-10 10:02 ` Nanzhe Zhao
0 siblings, 0 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-10 10:02 UTC (permalink / raw)
To: daeho43
Cc: chao, David.Hildenbrand, Dev.Jain, Ryan.Roberts, baohua,
daehojeong, jaegeuk, jyescas, kaleshsingh, linux-f2fs-devel,
linux-kernel, lipengfei28, nzzhao, zhangbo56, zhaonanzhe
Thanks for pointing out!
I choosed the design to let prepare_large_folio_write_begin() and
prepare_large_folio_atomic_write_begin() complete the read IO internally
to keep the code easy to implement, so I have to call them after the
f2fs_folio_wait_writeback() in f2fs_write_begin().
I'm going to add the writeback wait after re-locking the folio in
f2fs_folio_may_unlock_balance_fs(). For order-0, one more f2fs_folio_wait_writeback
probably doesn't matter much, right?
Thanks,
Nanzhe
^ permalink raw reply [flat|nested] 29+ messages in thread
* Re: [PATCH v3 03/17] f2fs: support regular file buffered writes on large folios
2026-10-09 16:12 ` [PATCH v3 03/17] f2fs: support regular file buffered writes on large folios Nanzhe Zhao
2026-10-09 18:34 ` [f2fs-dev] " Daeho Jeong
@ 2026-10-12 3:01 ` Chao Yu
1 sibling, 0 replies; 29+ messages in thread
From: Chao Yu @ 2026-10-12 3:01 UTC (permalink / raw)
To: Nanzhe Zhao, linux-f2fs-devel, Jaegeuk Kim
Cc: chao, Daeho Jeong, Barry Song, Juan Yescas, Dev Jain,
linux-kernel, David Hildenbrand, Bo Zhang, Kalesh Singh,
Nanzhe Zhao, Pengfei Li, Ryan Roberts
On 10/10/26 00:12, Nanzhe Zhao wrote:
> +/*
> + * Drop the folio lock when a node was changed, then balance the
> + * filesystem and reacquire the lock.
> + *
> + * Return: true if the folio became unusable while unlocked (being
> + * truncated), false if the folio is still usable.
> + */
> +static bool f2fs_folio_may_unlock_balance_fs(struct folio *folio,
f2fs_balance_fs_folio_locked() ?
> @@ -4198,11 +4501,15 @@ static int f2fs_write_begin(const struct kiocb *iocb,
>
> *foliop = folio;
>
> + /* Clamp the write length to the folio size. */
> + blen = min_t(unsigned int, len,
> + folio_size(folio) - offset_in_folio(folio, pos));
> +
> if (f2fs_is_atomic_file(inode))
> err = prepare_atomic_write_begin(sbi, folio, pos, len,
> &blkaddr, &need_balance);
> - else
> - err = prepare_write_begin(sbi, folio, pos, len,
> + else if (!folio_test_large(folio))
> + err = prepare_write_begin(sbi, folio, pos, blen,
> &blkaddr, &need_balance);
> if (err)
> goto put_folio;
> @@ -4222,7 +4529,19 @@ static int f2fs_write_begin(const struct kiocb *iocb,
>
> f2fs_folio_wait_writeback(folio, false, true);
>
> - if (len == folio_size(folio) || folio_test_uptodate(folio))
> + if (folio_test_large(folio)) {
> + err = prepare_large_folio_write_begin(inode,
> + folio, pos, blen);
Is it possible that we can relocate prepare_large_folio_write_begin() after
else if (!folio_test_large(folio))
err = prepare_write_begin(sbi, folio, pos, blen,
&blkaddr, &need_balance);
else
err = prepare_large_folio_write_begin(...);
Thanks,
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v3 04/17] f2fs: support atomic file large folios buffered write
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (2 preceding siblings ...)
2026-10-09 16:12 ` [PATCH v3 03/17] f2fs: support regular file buffered writes on large folios Nanzhe Zhao
@ 2026-10-09 16:12 ` Nanzhe Zhao
2026-10-12 3:06 ` Chao Yu
2026-10-09 16:12 ` [PATCH v3 05/17] f2fs: support large folio writeback Nanzhe Zhao
` (12 subsequent siblings)
16 siblings, 1 reply; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:12 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
ioctl can convert an inode with large folio support into an atomic
file. Support large folio buffered writes for atomic files as well.
Add a large folio atomic write_begin helper that reserves COW mappings
for the write range. For partial head and tail subpages, read the
existing data from either the COW inode or the original inode before
marking the subpage uptodate.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 86 +++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 68 insertions(+), 18 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index af2bb02e301f..315506e394ed 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -4246,18 +4246,16 @@ static int __reserve_data_block(struct inode *inode, pgoff_t index,
}
static int prepare_atomic_write_begin(struct f2fs_sb_info *sbi,
- struct folio *folio, loff_t pos, unsigned int len,
+ struct inode *inode, pgoff_t index,
block_t *blk_addr, bool *node_changed)
{
- struct inode *inode = folio->mapping->host;
struct inode *cow_inode = F2FS_I(inode)->cow_inode;
- pgoff_t index = folio->index;
int err = 0;
block_t ori_blk_addr = NULL_ADDR;
bool cow_has_reserved_block = false;
- /* If pos is beyond the end of file, reserve a new block in COW inode */
- if ((pos & PAGE_MASK) >= i_size_read(inode))
+ /* If index is beyond the end of file, reserve a new block in COW inode */
+ if ((index << PAGE_SHIFT) >= i_size_read(inode))
goto reserve_block;
/* Look for the block in COW inode first */
@@ -4423,6 +4421,61 @@ static int prepare_large_folio_write_begin(struct inode *inode,
return 0;
}
+static int prepare_large_folio_atomic_write_begin(struct inode *inode,
+ struct address_space *mapping, struct folio *folio, loff_t pos,
+ unsigned int len)
+{
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ size_t ori_off = offset_in_folio(folio, pos);
+ pgoff_t start, end, index;
+ int err = 0;
+
+ len = min_t(unsigned int, len, folio_size(folio) - ori_off);
+
+ if (!f2fs_ffs_find_or_alloc(folio))
+ return -ENOMEM;
+
+ /* Inline data must have been converted before reaching here. */
+ f2fs_bug_on(sbi, f2fs_has_inline_data(inode));
+
+ start = folio->index + (ori_off >> PAGE_SHIFT);
+ end = folio->index + ((ori_off + len - 1) >> PAGE_SHIFT);
+
+ for (index = start; index <= end; index++) {
+ block_t blkaddr = NULL_ADDR;
+ bool node_changed = false;
+ size_t off = (index - folio->index) << PAGE_SHIFT;
+
+ err = prepare_atomic_write_begin(sbi, inode, index,
+ &blkaddr, &node_changed);
+ if (err)
+ return err;
+
+ if (f2fs_ffs_test_blk_uptodate(folio, index))
+ goto balance;
+
+ if (blkaddr == NEW_ADDR) {
+ folio_zero_segment(folio, off, off + PAGE_SIZE);
+ f2fs_ffs_mark_subrange_uptodate(folio, off, PAGE_SIZE);
+ goto balance;
+ }
+
+ if (!f2fs_is_valid_blkaddr(sbi, blkaddr,
+ DATA_GENERIC_ENHANCE_READ))
+ return -EFSCORRUPTED;
+
+ err = f2fs_submit_page_read_sync(inode, folio, index,
+ blkaddr);
+ if (err)
+ return err;
+balance:
+ if (f2fs_folio_may_unlock_balance_fs(folio, mapping, node_changed))
+ return -EAGAIN;
+ }
+
+ return 0;
+}
+
static int f2fs_write_begin(const struct kiocb *iocb,
struct address_space *mapping,
loff_t pos, unsigned len, struct folio **foliop,
@@ -4505,8 +4558,8 @@ static int f2fs_write_begin(const struct kiocb *iocb,
blen = min_t(unsigned int, len,
folio_size(folio) - offset_in_folio(folio, pos));
- if (f2fs_is_atomic_file(inode))
- err = prepare_atomic_write_begin(sbi, folio, pos, len,
+ if (f2fs_is_atomic_file(inode) && !folio_test_large(folio))
+ err = prepare_atomic_write_begin(sbi, inode, folio->index,
&blkaddr, &need_balance);
else if (!folio_test_large(folio))
err = prepare_write_begin(sbi, folio, pos, blen,
@@ -4514,23 +4567,20 @@ static int f2fs_write_begin(const struct kiocb *iocb,
if (err)
goto put_folio;
- if (need_balance && !IS_NOQUOTA(inode) &&
- has_not_enough_free_secs(sbi, 0, 0)) {
+ if (f2fs_folio_may_unlock_balance_fs(folio, mapping, need_balance)) {
folio_unlock(folio);
- f2fs_balance_fs(sbi, true);
- folio_lock(folio);
- if (folio->mapping != mapping) {
- /* The folio got truncated from under us */
- folio_unlock(folio);
- folio_put(folio);
- goto repeat;
- }
+ folio_put(folio);
+ goto repeat;
}
f2fs_folio_wait_writeback(folio, false, true);
if (folio_test_large(folio)) {
- err = prepare_large_folio_write_begin(inode,
+ if (f2fs_is_atomic_file(inode))
+ err = prepare_large_folio_atomic_write_begin(inode,
+ mapping, folio, pos, len);
+ else
+ err = prepare_large_folio_write_begin(inode,
folio, pos, blen);
if (!err)
return 0;
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v3 04/17] f2fs: support atomic file large folios buffered write
2026-10-09 16:12 ` [PATCH v3 04/17] f2fs: support atomic file large folios buffered write Nanzhe Zhao
@ 2026-10-12 3:06 ` Chao Yu
0 siblings, 0 replies; 29+ messages in thread
From: Chao Yu @ 2026-10-12 3:06 UTC (permalink / raw)
To: Nanzhe Zhao, linux-f2fs-devel, Jaegeuk Kim
Cc: chao, Daeho Jeong, Barry Song, Juan Yescas, Dev Jain,
linux-kernel, David Hildenbrand, Bo Zhang, Kalesh Singh,
Nanzhe Zhao, Pengfei Li, Ryan Roberts
On 10/10/26 00:12, Nanzhe Zhao wrote:
> + /* If index is beyond the end of file, reserve a new block in COW inode */
> + if ((index << PAGE_SHIFT) >= i_size_read(inode))
Can you please check all "xxx << PAGE_SHIFT" statements in patchset to see if there
is overflow issue?
> + if (f2fs_folio_may_unlock_balance_fs(folio, mapping, need_balance)) {
> folio_unlock(folio);
> - f2fs_balance_fs(sbi, true);
> - folio_lock(folio);
> - if (folio->mapping != mapping) {
> - /* The folio got truncated from under us */
> - folio_unlock(folio);
> - folio_put(folio);
> - goto repeat;
> - }
> + folio_put(folio);
Then we can call f2fs_folio_put(, true) to clean up the codes?
> if (folio_test_large(folio)) {
> - err = prepare_large_folio_write_begin(inode,
> + if (f2fs_is_atomic_file(inode))
> + err = prepare_large_folio_atomic_write_begin(inode,
> + mapping, folio, pos, len);
> + else
> + err = prepare_large_folio_write_begin(inode,
> folio, pos, blen);
Same question as it in 03/17, can we relocate?
Thanks,
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v3 05/17] f2fs: support large folio writeback
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (3 preceding siblings ...)
2026-10-09 16:12 ` [PATCH v3 04/17] f2fs: support atomic file large folios buffered write Nanzhe Zhao
@ 2026-10-09 16:12 ` Nanzhe Zhao
2026-10-12 4:36 ` Chao Yu
2026-10-09 16:12 ` [PATCH v3 06/17] f2fs: account large folio dirty data at block granularity Nanzhe Zhao
` (11 subsequent siblings)
16 siblings, 1 reply; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:12 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
Large folio can contain multiple dirty ranges.
Add a folio-based writeback path for large-folio mapping files
and keep the legacy f2fs_write_cache_pages() path unchanged for
non large-folio mapping files.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 427 ++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 422 insertions(+), 5 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 315506e394ed..da388ed9cccc 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -334,7 +334,9 @@ static void f2fs_write_end_bio(struct bio *bio)
bio_for_each_folio_all(fi, bio) {
struct folio *folio = fi.folio;
+ unsigned int nr_pages = fi.length >> PAGE_SHIFT;
enum count_type type;
+ bool finished = true;
#ifdef CONFIG_F2FS_FS_COMPRESSION
if (f2fs_is_compressed_page(folio)) {
@@ -353,7 +355,16 @@ static void f2fs_write_end_bio(struct bio *bio)
}
}
- dec_cache_count(sbi, type);
+ if (f2fs_folio_has_ffs(folio)) {
+ struct f2fs_folio_state *ffs =
+ (struct f2fs_folio_state *)folio->private;
+
+ finished = atomic_sub_and_test(nr_pages,
+ &ffs->write_pages_pending);
+ }
+
+ while (nr_pages--)
+ dec_cache_count(sbi, type);
/*
* we should access sbi before folio_end_writeback() to
@@ -363,8 +374,10 @@ static void f2fs_write_end_bio(struct bio *bio)
wq_has_sleeper(&sbi->cp_wait))
wake_up(&sbi->cp_wait);
- folio_clear_f2fs_gcing(folio);
- folio_end_writeback(folio);
+ if (finished) {
+ folio_clear_f2fs_gcing(folio);
+ folio_end_writeback(folio);
+ }
}
bio_put(bio);
@@ -2885,7 +2898,7 @@ static unsigned int __ffs_mark_subrange_dirty(struct folio *folio,
return bitmap_weight(ffs->state, 2 * nr_subpages) - before;
}
-static void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
+void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
size_t offset, size_t len)
{
struct f2fs_folio_state *ffs;
@@ -2903,6 +2916,99 @@ static void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
spin_unlock_irqrestore(&ffs->state_lock, flags);
}
+static bool __ffs_clear_subrange_dirty(struct folio *folio,
+ struct f2fs_folio_state *ffs, size_t offset, size_t len)
+{
+ unsigned int nr_subpages = folio_nr_pages(folio);
+ unsigned int start, end;
+
+ start = offset >> PAGE_SHIFT;
+ end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ end = min(end, nr_subpages);
+
+ bitmap_clear(ffs->state, nr_subpages + start, end - start);
+ return find_next_bit(ffs->state, 2 * nr_subpages, nr_subpages) <
+ 2 * nr_subpages;
+}
+
+/**
+ * f2fs_ffs_clear_subrange_dirty_and_test - clear dirty bits and test remaining
+ * @folio: the large folio
+ * @offset: start byte offset within the folio
+ * @len: byte length of the subrange
+ *
+ * Clear the dirty bits of the 4K subpages covered by [offset, offset + len),
+ * and return whether the folio still has any dirty subpage left.
+ */
+bool f2fs_ffs_clear_subrange_dirty_and_test(struct folio *folio, size_t offset,
+ size_t len)
+{
+ struct f2fs_folio_state *ffs;
+ unsigned long flags;
+ bool dirty;
+
+ if (!f2fs_folio_has_ffs(folio))
+ return false;
+
+ ffs = (struct f2fs_folio_state *)folio->private;
+ spin_lock_irqsave(&ffs->state_lock, flags);
+ dirty = __ffs_clear_subrange_dirty(folio, ffs, offset, len);
+ spin_unlock_irqrestore(&ffs->state_lock, flags);
+
+ return dirty;
+}
+
+static unsigned int ffs_next_dirty_subpage(struct f2fs_folio_state *ffs,
+ const struct folio *folio, unsigned int start,
+ unsigned int end)
+{
+ unsigned int nr_subpages = folio_nr_pages(folio);
+
+ return find_next_bit(ffs->state, nr_subpages + end + 1,
+ nr_subpages + start) - nr_subpages;
+}
+
+static unsigned int ffs_next_clean_subpage(struct f2fs_folio_state *ffs,
+ const struct folio *folio, unsigned int start,
+ unsigned int end)
+{
+ unsigned int nr_subpages = folio_nr_pages(folio);
+
+ return find_next_zero_bit(ffs->state, nr_subpages + end + 1,
+ nr_subpages + start) - nr_subpages;
+}
+
+static unsigned int ffs_find_dirty_range(struct folio *folio,
+ u64 *range_start, u64 range_end)
+{
+ struct f2fs_folio_state *ffs;
+ unsigned int start, end, nr_pages;
+
+ if (*range_start >= range_end)
+ return 0;
+
+ if (!f2fs_folio_has_ffs(folio))
+ return range_end - *range_start;
+
+ ffs = (struct f2fs_folio_state *)folio->private;
+ start = offset_in_folio(folio, *range_start) >> PAGE_SHIFT;
+ end = DIV_ROUND_UP(min_not_zero(offset_in_folio(folio, range_end),
+ folio_size(folio)), PAGE_SIZE) - 1;
+
+ start = ffs_next_dirty_subpage(ffs, folio, start, end);
+ if (start > end)
+ return 0;
+
+ if (start == end)
+ nr_pages = 1;
+ else
+ nr_pages = ffs_next_clean_subpage(ffs, folio,
+ start + 1, end) - start;
+
+ *range_start = folio_pos(folio) + ((u64)start << PAGE_SHIFT);
+ return (u64)nr_pages << PAGE_SHIFT;
+}
+
static bool find_next_valid_block(const struct folio *folio,
size_t orig_off, size_t *need_off,
size_t len)
@@ -3486,6 +3592,143 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio)
return err;
}
+static int f2fs_write_folio_dirty_range(struct folio *folio, int *submitted,
+ struct writeback_control *wbc,
+ enum iostat_type io_type,
+ u64 *pos, u64 len)
+{
+ struct inode *inode = folio->mapping->host;
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ bool atomic_commit = f2fs_is_atomic_file(inode) &&
+ folio_test_f2fs_atomic(folio);
+ struct inode *dn_inode = atomic_commit ?
+ F2FS_I(inode)->cow_inode : inode;
+ struct f2fs_folio_state *ffs = NULL;
+ u64 folio_start = folio_pos(folio);
+ pgoff_t start_idx = (*pos - folio_start) >> PAGE_SHIFT;
+ pgoff_t end_idx = (*pos - folio_start + len - 1) >> PAGE_SHIFT;
+ int err = 0;
+
+ for (pgoff_t i = start_idx; i <= end_idx && !err; i++) {
+ struct dnode_of_data dn;
+ struct node_info ni;
+ pgoff_t data_idx = folio->index + i;
+ bool ipu_force = false;
+ bool dn_held = false;
+ bool submitted_blk = false;
+ struct f2fs_io_info fio = {
+ .sbi = sbi,
+ .ino = inode->i_ino,
+ .type = DATA,
+ .op = REQ_OP_WRITE,
+ .op_flags = wbc_to_write_flags(wbc),
+ .old_blkaddr = NULL_ADDR,
+ .folio = folio,
+ .folio_offset = i,
+ .folio_blkcnt = 1,
+ .encrypted_page = NULL,
+ .submitted = 0,
+ .need_lock = LOCK_DONE,
+ .meta_gc = f2fs_meta_inode_gc_required(inode) ? 1 : 0,
+ .io_type = io_type,
+ .io_wbc = wbc,
+ };
+
+ if (f2fs_folio_has_ffs(folio)) {
+ ffs = (struct f2fs_folio_state *)folio->private;
+ atomic_inc(&ffs->write_pages_pending);
+ }
+
+ set_new_dnode(&dn, dn_inode, NULL, NULL, 0);
+
+ if (need_inplace_update(&fio) &&
+ f2fs_lookup_read_extent_cache_block(inode, data_idx,
+ &fio.old_blkaddr)) {
+ if (!f2fs_is_valid_blkaddr(sbi, fio.old_blkaddr,
+ DATA_GENERIC_ENHANCE)) {
+ err = -EFSCORRUPTED;
+ goto block_done;
+ }
+ ipu_force = true;
+ goto got_it;
+ }
+
+ err = f2fs_get_dnode_of_data(&dn, data_idx, LOOKUP_NODE);
+
+ if (err)
+ goto block_done;
+ dn_held = true;
+
+ fio.old_blkaddr = dn.data_blkaddr;
+
+got_it:
+ if (__is_valid_data_blkaddr(fio.old_blkaddr) &&
+ !f2fs_is_valid_blkaddr(sbi, fio.old_blkaddr,
+ DATA_GENERIC_ENHANCE)) {
+ err = -EFSCORRUPTED;
+ goto block_done;
+ }
+
+ if (fio.meta_gc)
+ f2fs_wait_on_block_writeback(inode, fio.old_blkaddr);
+
+ if (ipu_force ||
+ (__is_valid_data_blkaddr(fio.old_blkaddr) &&
+ need_inplace_update(&fio))) {
+ f2fs_put_dnode(&dn);
+ dn_held = false;
+ err = f2fs_inplace_write_data(&fio);
+ trace_f2fs_do_write_data_page(folio, IPU);
+ if (err)
+ goto block_done;
+
+ if (submitted)
+ (*submitted)++;
+ submitted_blk = true;
+ set_inode_flag(inode, FI_UPDATE_WRITE);
+ goto block_done;
+ }
+
+ err = f2fs_get_node_info(sbi, dn.nid, &ni, false);
+ if (err)
+ goto block_done;
+
+ fio.version = ni.version;
+
+ f2fs_outplace_write_data(&dn, &fio);
+ /*
+ * The outplace write path failed to submit this block.
+ */
+ if (!fio.submitted)
+ goto block_done;
+ if (submitted)
+ (*submitted)++;
+ submitted_blk = true;
+ set_inode_flag(inode, FI_APPEND_WRITE);
+ trace_f2fs_do_write_data_page(folio, OPU);
+block_done:
+ if (dn_held)
+ f2fs_put_dnode(&dn);
+ /*
+ * If this block was not submitted, roll back its
+ * write pages pending.
+ */
+ if (!submitted_blk && ffs)
+ atomic_dec(&ffs->write_pages_pending);
+ if (!err) {
+ *pos = (data_idx + 1) << PAGE_SHIFT;
+ spin_lock(&F2FS_I(inode)->i_size_lock);
+ if (F2FS_I(inode)->last_disk_size < *pos)
+ F2FS_I(inode)->last_disk_size = *pos;
+ spin_unlock(&F2FS_I(inode)->i_size_lock);
+ } else {
+ file_set_keep_isize(inode);
+ }
+ }
+
+ return err;
+}
+
int f2fs_write_single_data_page(struct folio *folio, int *submitted,
struct bio **bio,
sector_t *last_block,
@@ -3935,6 +4178,176 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
return ret;
}
+static int f2fs_write_cache_folios(struct address_space *mapping,
+ struct writeback_control *wbc,
+ enum iostat_type io_type)
+{
+ struct folio *folio = NULL;
+ struct inode *inode = mapping->host;
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ struct f2fs_lock_context lc;
+ u64 pos = 0;
+ u64 end_pos = 0;
+ u32 r_len = 0;
+ int err = 0;
+ int submitted = 0;
+ int nwritten = 0;
+ bool op_locked = false;
+ bool next = false;
+ bool retry = false;
+
+ if (get_dirty_pages(inode) <= SM_I(sbi)->min_hot_blocks)
+ set_inode_flag(inode, FI_HOT_DATA);
+ else
+ clear_inode_flag(inode, FI_HOT_DATA);
+
+ while ((folio = writeback_iter(mapping, wbc, folio, &err))) {
+ struct f2fs_folio_state *ffs = NULL;
+ u64 isize;
+ size_t poff;
+ pgoff_t end_index;
+ bool verity_in_progress;
+ int folio_submitted = 0;
+ bool bias_added = false;
+
+ submitted = 0;
+ next = true;
+ retry = false;
+
+ if (err) {
+ folio_redirty_for_writepage(wbc, folio);
+ goto retry_out;
+ }
+
+ if (atomic_read(&sbi->wb_sync_req[DATA]) &&
+ wbc->sync_mode == WB_SYNC_NONE) {
+ folio_redirty_for_writepage(wbc, folio);
+ next = false;
+ goto retry_out;
+ }
+retry:
+ pos = folio_pos(folio);
+ end_pos = pos + folio_size(folio);
+ isize = i_size_read(inode);
+ verity_in_progress = f2fs_verity_in_progress(inode);
+ poff = 0;
+ end_index = 0;
+
+ if (retry) {
+
+ if (unlikely(folio->mapping != mapping))
+ goto retry_out;
+
+ if (!folio_test_dirty(folio))
+ goto retry_out;
+
+ if (folio_test_writeback(folio)) {
+ if (wbc->sync_mode == WB_SYNC_NONE)
+ goto retry_out;
+ f2fs_folio_wait_writeback(folio, true, true);
+ }
+
+ if (!folio_clear_dirty_for_io(folio))
+ goto retry_out;
+ }
+
+ /* To avoid dealing with the complexity for one subrange is in bio
+ * while we trylock_op failed before writing another subrange.
+ * Try to lock_op before any subrange write for the folio.
+ */
+ if (!op_locked) {
+ if (!f2fs_trylock_op(sbi, &lc)) {
+ folio_redirty_for_writepage(wbc, folio);
+ err = 0;
+ if (wbc->sync_mode != WB_SYNC_ALL)
+ goto retry_out;
+
+ retry = true;
+ folio_unlock(folio);
+ f2fs_io_schedule_timeout(DEFAULT_SCHEDULE_TIMEOUT);
+ folio_lock(folio);
+ goto retry;
+ }
+ op_locked = true;
+ }
+
+ if (!verity_in_progress) {
+ poff = offset_in_folio(folio, isize);
+ end_index = isize >> PAGE_SHIFT;
+
+ if (folio->index > end_index ||
+ (folio->index == end_index && poff == 0))
+ goto out;
+
+ if (end_pos > isize) {
+ folio_zero_segment(folio, poff, folio_size(folio));
+ end_pos = isize;
+ }
+ }
+
+ folio_start_writeback(folio);
+
+ if (!bias_added && f2fs_folio_has_ffs(folio)) {
+ ffs = (struct f2fs_folio_state *)folio->private;
+ WARN_ON_ONCE(atomic_read(&ffs->write_pages_pending) != 0);
+ atomic_inc(&ffs->write_pages_pending);
+ bias_added = true;
+ }
+
+ while ((r_len = ffs_find_dirty_range(folio, &pos, end_pos))) {
+ err = f2fs_write_folio_dirty_range(folio, &submitted,
+ wbc, io_type, &pos, r_len);
+ folio_submitted += submitted;
+ if (err)
+ goto out;
+
+ nwritten += submitted;
+ }
+
+ if (!err && folio_submitted &&
+ f2fs_is_atomic_file(inode) &&
+ folio_test_f2fs_atomic(folio))
+ folio_clear_f2fs_atomic(folio);
+
+out:
+ /*
+ * Clear the dirty state of the subranges that were written back.
+ * If some subranges are still dirty (e.g. the folio was only
+ * partially written back), the folio must stay dirty so that
+ * the remaining subranges are written back later.
+ */
+ if (f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
+ (err ? pos : end_pos) - folio_pos(folio)))
+ folio_redirty_for_writepage(wbc, folio);
+ else
+ inode_dec_dirty_pages(inode);
+
+ if (bias_added) {
+ if (atomic_dec_and_test(&ffs->write_pages_pending))
+ folio_end_writeback(folio);
+ } else if (!folio_submitted && folio_test_writeback(folio)) {
+ folio_end_writeback(folio);
+ }
+
+retry_out:
+ folio_unlock(folio);
+
+ if (op_locked) {
+ f2fs_unlock_op(sbi, &lc);
+ op_locked = false;
+ }
+
+ if (!next)
+ wbc->nr_to_write = 0;
+ }
+
+ if (nwritten)
+ f2fs_submit_merged_write_cond(F2FS_M_SB(mapping), mapping->host,
+ NULL);
+
+ return err;
+}
+
static inline bool __should_serialize_io(struct inode *inode,
struct writeback_control *wbc)
{
@@ -4029,7 +4442,11 @@ static int __f2fs_write_data_pages(struct address_space *mapping,
account_writeback(inode, true);
blk_start_plug(&plug);
- ret = f2fs_write_cache_pages(mapping, wbc, io_type);
+ if (mapping_large_folio_support(inode->i_mapping) &&
+ !f2fs_has_inline_data(inode))
+ ret = f2fs_write_cache_folios(mapping, wbc, io_type);
+ else
+ ret = f2fs_write_cache_pages(mapping, wbc, io_type);
blk_finish_plug(&plug);
account_writeback(inode, false);
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v3 05/17] f2fs: support large folio writeback
2026-10-09 16:12 ` [PATCH v3 05/17] f2fs: support large folio writeback Nanzhe Zhao
@ 2026-10-12 4:36 ` Chao Yu
0 siblings, 0 replies; 29+ messages in thread
From: Chao Yu @ 2026-10-12 4:36 UTC (permalink / raw)
To: Nanzhe Zhao, linux-f2fs-devel, Jaegeuk Kim
Cc: chao, Daeho Jeong, Barry Song, Juan Yescas, Dev Jain,
linux-kernel, David Hildenbrand, Bo Zhang, Kalesh Singh,
Nanzhe Zhao, Pengfei Li, Ryan Roberts
On 10/10/26 00:12, Nanzhe Zhao wrote:
> Large folio can contain multiple dirty ranges.
> Add a folio-based writeback path for large-folio mapping files
> and keep the legacy f2fs_write_cache_pages() path unchanged for
> non large-folio mapping files.
>
> Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
> ---
> fs/f2fs/data.c | 427 ++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 422 insertions(+), 5 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 315506e394ed..da388ed9cccc 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -334,7 +334,9 @@ static void f2fs_write_end_bio(struct bio *bio)
>
> bio_for_each_folio_all(fi, bio) {
> struct folio *folio = fi.folio;
> + unsigned int nr_pages = fi.length >> PAGE_SHIFT;
> enum count_type type;
> + bool finished = true;
>
> #ifdef CONFIG_F2FS_FS_COMPRESSION
> if (f2fs_is_compressed_page(folio)) {
> @@ -353,7 +355,16 @@ static void f2fs_write_end_bio(struct bio *bio)
> }
> }
>
> - dec_cache_count(sbi, type);
> + if (f2fs_folio_has_ffs(folio)) {
> + struct f2fs_folio_state *ffs =
> + (struct f2fs_folio_state *)folio->private;
> +
> + finished = atomic_sub_and_test(nr_pages,
> + &ffs->write_pages_pending);
> + }
> +
> + while (nr_pages--)
> + dec_cache_count(sbi, type);
>
> /*
> * we should access sbi before folio_end_writeback() to
> @@ -363,8 +374,10 @@ static void f2fs_write_end_bio(struct bio *bio)
> wq_has_sleeper(&sbi->cp_wait))
> wake_up(&sbi->cp_wait);
>
> - folio_clear_f2fs_gcing(folio);
> - folio_end_writeback(folio);
> + if (finished) {
> + folio_clear_f2fs_gcing(folio);
> + folio_end_writeback(folio);
> + }
> }
>
> bio_put(bio);
> @@ -2885,7 +2898,7 @@ static unsigned int __ffs_mark_subrange_dirty(struct folio *folio,
> return bitmap_weight(ffs->state, 2 * nr_subpages) - before;
> }
>
> -static void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
> +void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
> size_t offset, size_t len)
> {
> struct f2fs_folio_state *ffs;
> @@ -2903,6 +2916,99 @@ static void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
> spin_unlock_irqrestore(&ffs->state_lock, flags);
> }
>
> +static bool __ffs_clear_subrange_dirty(struct folio *folio,
> + struct f2fs_folio_state *ffs, size_t offset, size_t len)
> +{
> + unsigned int nr_subpages = folio_nr_pages(folio);
> + unsigned int start, end;
> +
> + start = offset >> PAGE_SHIFT;
> + end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
> + end = min(end, nr_subpages);
> +
> + bitmap_clear(ffs->state, nr_subpages + start, end - start);
> + return find_next_bit(ffs->state, 2 * nr_subpages, nr_subpages) <
> + 2 * nr_subpages;
> +}
> +
> +/**
> + * f2fs_ffs_clear_subrange_dirty_and_test - clear dirty bits and test remaining
> + * @folio: the large folio
> + * @offset: start byte offset within the folio
> + * @len: byte length of the subrange
> + *
> + * Clear the dirty bits of the 4K subpages covered by [offset, offset + len),
> + * and return whether the folio still has any dirty subpage left.
> + */
> +bool f2fs_ffs_clear_subrange_dirty_and_test(struct folio *folio, size_t offset,
> + size_t len)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned long flags;
> + bool dirty;
> +
> + if (!f2fs_folio_has_ffs(folio))
> + return false;
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> + spin_lock_irqsave(&ffs->state_lock, flags);
> + dirty = __ffs_clear_subrange_dirty(folio, ffs, offset, len);
> + spin_unlock_irqrestore(&ffs->state_lock, flags);
> +
> + return dirty;
> +}
> +
> +static unsigned int ffs_next_dirty_subpage(struct f2fs_folio_state *ffs,
> + const struct folio *folio, unsigned int start,
> + unsigned int end)
> +{
> + unsigned int nr_subpages = folio_nr_pages(folio);
> +
> + return find_next_bit(ffs->state, nr_subpages + end + 1,
> + nr_subpages + start) - nr_subpages;
> +}
> +
> +static unsigned int ffs_next_clean_subpage(struct f2fs_folio_state *ffs,
> + const struct folio *folio, unsigned int start,
> + unsigned int end)
> +{
> + unsigned int nr_subpages = folio_nr_pages(folio);
> +
> + return find_next_zero_bit(ffs->state, nr_subpages + end + 1,
> + nr_subpages + start) - nr_subpages;
> +}
> +
> +static unsigned int ffs_find_dirty_range(struct folio *folio,
> + u64 *range_start, u64 range_end)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned int start, end, nr_pages;
> +
> + if (*range_start >= range_end)
> + return 0;
> +
> + if (!f2fs_folio_has_ffs(folio))
> + return range_end - *range_start;
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> + start = offset_in_folio(folio, *range_start) >> PAGE_SHIFT;
> + end = DIV_ROUND_UP(min_not_zero(offset_in_folio(folio, range_end),
> + folio_size(folio)), PAGE_SIZE) - 1;
> +
> + start = ffs_next_dirty_subpage(ffs, folio, start, end);
> + if (start > end)
> + return 0;
> +
> + if (start == end)
> + nr_pages = 1;
> + else
> + nr_pages = ffs_next_clean_subpage(ffs, folio,
> + start + 1, end) - start;
> +
> + *range_start = folio_pos(folio) + ((u64)start << PAGE_SHIFT);
> + return (u64)nr_pages << PAGE_SHIFT;
> +}
> +
> static bool find_next_valid_block(const struct folio *folio,
> size_t orig_off, size_t *need_off,
> size_t len)
> @@ -3486,6 +3592,143 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio)
> return err;
> }
>
> +static int f2fs_write_folio_dirty_range(struct folio *folio, int *submitted,
> + struct writeback_control *wbc,
> + enum iostat_type io_type,
> + u64 *pos, u64 len)
> +{
> + struct inode *inode = folio->mapping->host;
> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> + bool atomic_commit = f2fs_is_atomic_file(inode) &&
> + folio_test_f2fs_atomic(folio);
> + struct inode *dn_inode = atomic_commit ?
> + F2FS_I(inode)->cow_inode : inode;
> + struct f2fs_folio_state *ffs = NULL;
> + u64 folio_start = folio_pos(folio);
> + pgoff_t start_idx = (*pos - folio_start) >> PAGE_SHIFT;
> + pgoff_t end_idx = (*pos - folio_start + len - 1) >> PAGE_SHIFT;
> + int err = 0;
> +
> + for (pgoff_t i = start_idx; i <= end_idx && !err; i++) {
> + struct dnode_of_data dn;
> + struct node_info ni;
> + pgoff_t data_idx = folio->index + i;
> + bool ipu_force = false;
> + bool dn_held = false;
> + bool submitted_blk = false;
> + struct f2fs_io_info fio = {
> + .sbi = sbi,
> + .ino = inode->i_ino,
> + .type = DATA,
> + .op = REQ_OP_WRITE,
> + .op_flags = wbc_to_write_flags(wbc),
> + .old_blkaddr = NULL_ADDR,
> + .folio = folio,
> + .folio_offset = i,
> + .folio_blkcnt = 1,
> + .encrypted_page = NULL,
> + .submitted = 0,
> + .need_lock = LOCK_DONE,
> + .meta_gc = f2fs_meta_inode_gc_required(inode) ? 1 : 0,
> + .io_type = io_type,
> + .io_wbc = wbc,
> + };
> +
> + if (f2fs_folio_has_ffs(folio)) {
> + ffs = (struct f2fs_folio_state *)folio->private;
> + atomic_inc(&ffs->write_pages_pending);
> + }
> +
> + set_new_dnode(&dn, dn_inode, NULL, NULL, 0);
> +
> + if (need_inplace_update(&fio) &&
> + f2fs_lookup_read_extent_cache_block(inode, data_idx,
> + &fio.old_blkaddr)) {
> + if (!f2fs_is_valid_blkaddr(sbi, fio.old_blkaddr,
> + DATA_GENERIC_ENHANCE)) {
> + err = -EFSCORRUPTED;
> + goto block_done;
> + }
> + ipu_force = true;
> + goto got_it;
> + }
> +
> + err = f2fs_get_dnode_of_data(&dn, data_idx, LOOKUP_NODE);
> +
Unneeded blank line.
> + if (err)
> + goto block_done;
> + dn_held = true;
> +
> + fio.old_blkaddr = dn.data_blkaddr;
> +
> +got_it:
> + if (__is_valid_data_blkaddr(fio.old_blkaddr) &&
> + !f2fs_is_valid_blkaddr(sbi, fio.old_blkaddr,
> + DATA_GENERIC_ENHANCE)) {
> + err = -EFSCORRUPTED;
> + goto block_done;
> + }
> +
> + if (fio.meta_gc)
> + f2fs_wait_on_block_writeback(inode, fio.old_blkaddr);
> +
> + if (ipu_force ||
> + (__is_valid_data_blkaddr(fio.old_blkaddr) &&
> + need_inplace_update(&fio))) {
> + f2fs_put_dnode(&dn);
> + dn_held = false;
> + err = f2fs_inplace_write_data(&fio);
> + trace_f2fs_do_write_data_page(folio, IPU);
> + if (err)
> + goto block_done;
> +
> + if (submitted)
> + (*submitted)++;
> + submitted_blk = true;
> + set_inode_flag(inode, FI_UPDATE_WRITE);
> + goto block_done;
> + }
> +
> + err = f2fs_get_node_info(sbi, dn.nid, &ni, false);
> + if (err)
> + goto block_done;
> +
> + fio.version = ni.version;
> +
> + f2fs_outplace_write_data(&dn, &fio);
> + /*
> + * The outplace write path failed to submit this block.
> + */
> + if (!fio.submitted)
> + goto block_done;
> + if (submitted)
> + (*submitted)++;
> + submitted_blk = true;
> + set_inode_flag(inode, FI_APPEND_WRITE);
> + trace_f2fs_do_write_data_page(folio, OPU);
> +block_done:
> + if (dn_held)
> + f2fs_put_dnode(&dn);
> + /*
> + * If this block was not submitted, roll back its
> + * write pages pending.
> + */
> + if (!submitted_blk && ffs)
> + atomic_dec(&ffs->write_pages_pending);
> + if (!err) {
> + *pos = (data_idx + 1) << PAGE_SHIFT;
> + spin_lock(&F2FS_I(inode)->i_size_lock);
> + if (F2FS_I(inode)->last_disk_size < *pos)
> + F2FS_I(inode)->last_disk_size = *pos;
> + spin_unlock(&F2FS_I(inode)->i_size_lock);
> + } else {
> + file_set_keep_isize(inode);
> + }
> + }
> +
> + return err;
> +}
> +
> int f2fs_write_single_data_page(struct folio *folio, int *submitted,
> struct bio **bio,
> sector_t *last_block,
> @@ -3935,6 +4178,176 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> return ret;
> }
>
> +static int f2fs_write_cache_folios(struct address_space *mapping,
> + struct writeback_control *wbc,
> + enum iostat_type io_type)
> +{
> + struct folio *folio = NULL;
> + struct inode *inode = mapping->host;
> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> + struct f2fs_lock_context lc;
> + u64 pos = 0;
> + u64 end_pos = 0;
> + u32 r_len = 0;
> + int err = 0;
> + int submitted = 0;
> + int nwritten = 0;
> + bool op_locked = false;
> + bool next = false;
> + bool retry = false;
> +
> + if (get_dirty_pages(inode) <= SM_I(sbi)->min_hot_blocks)
> + set_inode_flag(inode, FI_HOT_DATA);
> + else
> + clear_inode_flag(inode, FI_HOT_DATA);
> +
> + while ((folio = writeback_iter(mapping, wbc, folio, &err))) {
> + struct f2fs_folio_state *ffs = NULL;
> + u64 isize;
> + size_t poff;
> + pgoff_t end_index;
> + bool verity_in_progress;
> + int folio_submitted = 0;
> + bool bias_added = false;
> +
> + submitted = 0;
> + next = true;
> + retry = false;
> +
> + if (err) {
> + folio_redirty_for_writepage(wbc, folio);
> + goto retry_out;
> + }
> +
> + if (atomic_read(&sbi->wb_sync_req[DATA]) &&
> + wbc->sync_mode == WB_SYNC_NONE) {
> + folio_redirty_for_writepage(wbc, folio);
> + next = false;
> + goto retry_out;
> + }
> +retry:
> + pos = folio_pos(folio);
> + end_pos = pos + folio_size(folio);
> + isize = i_size_read(inode);
> + verity_in_progress = f2fs_verity_in_progress(inode);
> + poff = 0;
> + end_index = 0;
> +
> + if (retry) {
> +
> + if (unlikely(folio->mapping != mapping))
> + goto retry_out;
> +
> + if (!folio_test_dirty(folio))
> + goto retry_out;
> +
> + if (folio_test_writeback(folio)) {
> + if (wbc->sync_mode == WB_SYNC_NONE)
> + goto retry_out;
> + f2fs_folio_wait_writeback(folio, true, true);
> + }
> +
> + if (!folio_clear_dirty_for_io(folio))
> + goto retry_out;
> + }
> +
> + /* To avoid dealing with the complexity for one subrange is in bio
> + * while we trylock_op failed before writing another subrange.
> + * Try to lock_op before any subrange write for the folio.
> + */
> + if (!op_locked) {
> + if (!f2fs_trylock_op(sbi, &lc)) {
> + folio_redirty_for_writepage(wbc, folio);
> + err = 0;
> + if (wbc->sync_mode != WB_SYNC_ALL)
> + goto retry_out;
> +
> + retry = true;
> + folio_unlock(folio);
> + f2fs_io_schedule_timeout(DEFAULT_SCHEDULE_TIMEOUT);
> + folio_lock(folio);
> + goto retry;
> + }
> + op_locked = true;
> + }
> +
> + if (!verity_in_progress) {
> + poff = offset_in_folio(folio, isize);
> + end_index = isize >> PAGE_SHIFT;
> +
> + if (folio->index > end_index ||
> + (folio->index == end_index && poff == 0))
> + goto out;
> +
> + if (end_pos > isize) {
> + folio_zero_segment(folio, poff, folio_size(folio));
> + end_pos = isize;
> + }
> + }
> +
> + folio_start_writeback(folio);
> +
> + if (!bias_added && f2fs_folio_has_ffs(folio)) {
> + ffs = (struct f2fs_folio_state *)folio->private;
> + WARN_ON_ONCE(atomic_read(&ffs->write_pages_pending) != 0);
> + atomic_inc(&ffs->write_pages_pending);
> + bias_added = true;
> + }
> +
> + while ((r_len = ffs_find_dirty_range(folio, &pos, end_pos))) {
> + err = f2fs_write_folio_dirty_range(folio, &submitted,
> + wbc, io_type, &pos, r_len);
> + folio_submitted += submitted;
> + if (err)
> + goto out;
> +
> + nwritten += submitted;
Do we need to update nwritten before goto out? in case if there is partial
blocks were cached in bio and err is valid, otherwise we may missed to call
f2fs_submit_merged_write_cond() below.
> + }
> +
> + if (!err && folio_submitted &&
No need to check err because in above loop it will jump to out if
err is valid?
> + f2fs_is_atomic_file(inode) &&
> + folio_test_f2fs_atomic(folio))
> + folio_clear_f2fs_atomic(folio);
> +
> +out:
> + /*
> + * Clear the dirty state of the subranges that were written back.
> + * If some subranges are still dirty (e.g. the folio was only
> + * partially written back), the folio must stay dirty so that
> + * the remaining subranges are written back later.
> + */
> + if (f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
> + (err ? pos : end_pos) - folio_pos(folio)))
> + folio_redirty_for_writepage(wbc, folio);
> + else
> + inode_dec_dirty_pages(inode);
> +
> + if (bias_added) {
> + if (atomic_dec_and_test(&ffs->write_pages_pending))
> + folio_end_writeback(folio);
> + } else if (!folio_submitted && folio_test_writeback(folio)) {
> + folio_end_writeback(folio);
> + }
> +
> +retry_out:
> + folio_unlock(folio);
> +
> + if (op_locked) {
> + f2fs_unlock_op(sbi, &lc);
> + op_locked = false;
> + }
It's trivial though, how about reordering f2fs_unlock_op and folio_unlock?
folio_lock -> f2fs_trylock_op -> .. -> f2fs_unlock_op -> folio_unlock
> +
> + if (!next)
The only case we set next is
if (atomic_read(&sbi->wb_sync_req[DATA]) &&
wbc->sync_mode == WB_SYNC_NONE) {
folio_redirty_for_writepage(wbc, folio);
next = false;
goto retry_out;
}
Can we handle below logic in above branch?
> + wbc->nr_to_write = 0;
struct writeback_control {
/* public fields that can be set and/or consumed by the caller: */
long nr_to_write; /* Write this many pages, and decrement
this for each page written */
long pages_skipped; /* Pages which were not written */
we should decrease nr_to_write only after we have writebacked page, so
shouldn't we increase pages_skipped instead for this case?
Thanks,
> + }
> +
> + if (nwritten)
> + f2fs_submit_merged_write_cond(F2FS_M_SB(mapping), mapping->host,
> + NULL);
> +
> + return err;
> +}
> +
> static inline bool __should_serialize_io(struct inode *inode,
> struct writeback_control *wbc)
> {
> @@ -4029,7 +4442,11 @@ static int __f2fs_write_data_pages(struct address_space *mapping,
> account_writeback(inode, true);
>
> blk_start_plug(&plug);
> - ret = f2fs_write_cache_pages(mapping, wbc, io_type);
> + if (mapping_large_folio_support(inode->i_mapping) &&
> + !f2fs_has_inline_data(inode))
> + ret = f2fs_write_cache_folios(mapping, wbc, io_type);
> + else
> + ret = f2fs_write_cache_pages(mapping, wbc, io_type);
> blk_finish_plug(&plug);
>
> account_writeback(inode, false);
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v3 06/17] f2fs: account large folio dirty data at block granularity
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (4 preceding siblings ...)
2026-10-09 16:12 ` [PATCH v3 05/17] f2fs: support large folio writeback Nanzhe Zhao
@ 2026-10-09 16:12 ` Nanzhe Zhao
2026-10-12 6:54 ` Chao Yu
2026-10-09 16:12 ` [PATCH v3 07/17] f2fs: remove mappedtodisk flag usage in mmap write path Nanzhe Zhao
` (10 subsequent siblings)
16 siblings, 1 reply; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:12 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
Originally inode->dirty_pages was accounted once per folio, but f2fs
needs the counter to be accounted in blocks.
This introduces batch dirty page add/sub accounting; for a large folio
the changed dirty page count is computed from the dirty bitmap bit
changes.
Found by f2fs/006 (lfs + checkpoint=disable) and generic/363.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/checkpoint.c | 38 ++++++++++++++++++++++----
fs/f2fs/data.c | 24 ++++++++++++----
fs/f2fs/f2fs.h | 65 ++++++++++++++++++++++++++++++++++----------
3 files changed, 101 insertions(+), 26 deletions(-)
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 81c1c2de936f..49075c840c61 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1316,20 +1316,46 @@ static void __remove_dirty_inode(struct inode *inode, enum inode_type type)
stat_dec_dirty_inode(F2FS_I_SB(inode), type);
}
-void f2fs_update_dirty_folio(struct inode *inode, struct folio *folio)
+/*
+ * Account @nr dirty pages (negative when dirtiness is cleared) for @inode.
+ */
+void f2fs_account_dirty_pages(struct inode *inode, int nr)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
enum inode_type type = S_ISDIR(inode->i_mode) ? DIR_INODE : FILE_INODE;
- if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode) &&
- !S_ISLNK(inode->i_mode))
+ if (!nr)
return;
spin_lock(&sbi->inode_lock[type]);
- if (type != FILE_INODE || test_opt(sbi, DATA_FLUSH))
- __add_dirty_inode(inode, type);
- inode_inc_dirty_pages(inode);
+ if (nr > 0) {
+ if (type != FILE_INODE || test_opt(sbi, DATA_FLUSH))
+ __add_dirty_inode(inode, type);
+ inode_inc_dirty_pages_nr(inode, nr);
+ } else {
+ inode_dec_dirty_pages_nr(inode, -nr);
+ __remove_dirty_inode(inode, type);
+ }
spin_unlock(&sbi->inode_lock[type]);
+}
+
+void f2fs_update_dirty_folio(struct inode *inode, struct folio *folio)
+{
+ if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode) &&
+ !S_ISLNK(inode->i_mode))
+ return;
+
+ /*
+ * Large folios have a subpage dirty bitmap, so defer their dirty accounting
+ * to the f2fs_ffs_*subrange_dirty*() helpers. This avoids nesting
+ * ffs->state_lock with the inode dirty list lock.
+ */
+ if (f2fs_folio_has_ffs(folio)) {
+ folio_set_f2fs_reference(folio);
+ return;
+ }
+
+ f2fs_account_dirty_pages(inode, 1);
folio_set_f2fs_reference(folio);
}
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index da388ed9cccc..d45fbe0db161 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2902,6 +2902,7 @@ void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
size_t offset, size_t len)
{
struct f2fs_folio_state *ffs;
+ unsigned int set;
unsigned long flags;
f2fs_bug_on(F2FS_F_SB(folio), offset + len > folio_size(folio));
@@ -2912,21 +2913,27 @@ void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
ffs = (struct f2fs_folio_state *)folio->private;
spin_lock_irqsave(&ffs->state_lock, flags);
- __ffs_mark_subrange_dirty(folio, ffs, offset, len);
+ set = __ffs_mark_subrange_dirty(folio, ffs, offset, len);
spin_unlock_irqrestore(&ffs->state_lock, flags);
+
+ if (set)
+ f2fs_account_dirty_pages(folio->mapping->host, set);
}
static bool __ffs_clear_subrange_dirty(struct folio *folio,
- struct f2fs_folio_state *ffs, size_t offset, size_t len)
+ struct f2fs_folio_state *ffs, size_t offset, size_t len,
+ unsigned int *cleared)
{
unsigned int nr_subpages = folio_nr_pages(folio);
- unsigned int start, end;
+ unsigned int start, end, before;
start = offset >> PAGE_SHIFT;
end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
end = min(end, nr_subpages);
+ before = bitmap_weight(ffs->state, 2 * nr_subpages);
bitmap_clear(ffs->state, nr_subpages + start, end - start);
+ *cleared = before - bitmap_weight(ffs->state, 2 * nr_subpages);
return find_next_bit(ffs->state, 2 * nr_subpages, nr_subpages) <
2 * nr_subpages;
}
@@ -2938,13 +2945,15 @@ static bool __ffs_clear_subrange_dirty(struct folio *folio,
* @len: byte length of the subrange
*
* Clear the dirty bits of the 4K subpages covered by [offset, offset + len),
- * and return whether the folio still has any dirty subpage left.
+ * account the cleared subpages against the inode dirty counters, and return
+ * whether the folio still has any dirty subpage left.
*/
bool f2fs_ffs_clear_subrange_dirty_and_test(struct folio *folio, size_t offset,
size_t len)
{
struct f2fs_folio_state *ffs;
unsigned long flags;
+ unsigned int cleared = 0;
bool dirty;
if (!f2fs_folio_has_ffs(folio))
@@ -2952,9 +2961,12 @@ bool f2fs_ffs_clear_subrange_dirty_and_test(struct folio *folio, size_t offset,
ffs = (struct f2fs_folio_state *)folio->private;
spin_lock_irqsave(&ffs->state_lock, flags);
- dirty = __ffs_clear_subrange_dirty(folio, ffs, offset, len);
+ dirty = __ffs_clear_subrange_dirty(folio, ffs, offset, len, &cleared);
spin_unlock_irqrestore(&ffs->state_lock, flags);
+ if (cleared)
+ f2fs_account_dirty_pages(folio->mapping->host, -cleared);
+
return dirty;
}
@@ -4319,7 +4331,7 @@ static int f2fs_write_cache_folios(struct address_space *mapping,
if (f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
(err ? pos : end_pos) - folio_pos(folio)))
folio_redirty_for_writepage(wbc, folio);
- else
+ else if (!f2fs_folio_has_ffs(folio))
inode_dec_dirty_pages(inode);
if (bias_added) {
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e14275f98fe7..2cf98f49c876 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2916,9 +2916,10 @@ static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
f2fs_i_blocks_write(inode, count, false, true);
}
-static inline void inc_cache_count(struct f2fs_sb_info *sbi, int count_type)
+static inline void inc_cache_count_nr(struct f2fs_sb_info *sbi,
+ int count_type, int nr)
{
- atomic_inc(&sbi->nr_caches[count_type]);
+ atomic_add(nr, &sbi->nr_caches[count_type]);
if (count_type == F2FS_DIRTY_DENTS ||
count_type == F2FS_DIRTY_NODES ||
@@ -2928,31 +2929,66 @@ static inline void inc_cache_count(struct f2fs_sb_info *sbi, int count_type)
set_sbi_flag(sbi, SBI_IS_DIRTY);
}
-static inline void inode_inc_dirty_pages(struct inode *inode)
+static inline void dec_cache_count_nr(struct f2fs_sb_info *sbi,
+ int count_type, int nr)
{
- atomic_inc(&F2FS_I(inode)->dirty_pages);
- inc_cache_count(F2FS_I_SB(inode), S_ISDIR(inode->i_mode) ?
- F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA);
- if (IS_NOQUOTA(inode))
- inc_cache_count(F2FS_I_SB(inode), F2FS_DIRTY_QDATA);
+ atomic_sub(nr, &sbi->nr_caches[count_type]);
+}
+
+static inline void inc_cache_count(struct f2fs_sb_info *sbi, int count_type)
+{
+ inc_cache_count_nr(sbi, count_type, 1);
}
static inline void dec_cache_count(struct f2fs_sb_info *sbi, int count_type)
{
- atomic_dec(&sbi->nr_caches[count_type]);
+ dec_cache_count_nr(sbi, count_type, 1);
}
-static inline void inode_dec_dirty_pages(struct inode *inode)
+/*
+ * Account @nr dirty pages for @inode; one page is
+ * (PAGE_SIZE >> log_blocksize) filesystem blocks.
+ */
+static inline void inode_inc_dirty_pages_nr(struct inode *inode, int nr)
+{
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ int blocks = nr * (PAGE_SIZE >> sbi->log_blocksize);
+
+ atomic_add(blocks, &F2FS_I(inode)->dirty_pages);
+ if (S_ISDIR(inode->i_mode))
+ inc_cache_count_nr(sbi, F2FS_DIRTY_DENTS, blocks);
+ else
+ inc_cache_count_nr(sbi, F2FS_DIRTY_DATA, blocks);
+ if (IS_NOQUOTA(inode))
+ inc_cache_count_nr(sbi, F2FS_DIRTY_QDATA, blocks);
+}
+
+static inline void inode_dec_dirty_pages_nr(struct inode *inode, int nr)
{
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ int blocks = nr * (PAGE_SIZE >> sbi->log_blocksize);
+
if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode) &&
!S_ISLNK(inode->i_mode))
return;
- atomic_dec(&F2FS_I(inode)->dirty_pages);
- dec_cache_count(F2FS_I_SB(inode), S_ISDIR(inode->i_mode) ?
- F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA);
+ atomic_sub(blocks, &F2FS_I(inode)->dirty_pages);
+ if (S_ISDIR(inode->i_mode))
+ dec_cache_count_nr(sbi, F2FS_DIRTY_DENTS, blocks);
+ else
+ dec_cache_count_nr(sbi, F2FS_DIRTY_DATA, blocks);
if (IS_NOQUOTA(inode))
- dec_cache_count(F2FS_I_SB(inode), F2FS_DIRTY_QDATA);
+ dec_cache_count_nr(sbi, F2FS_DIRTY_QDATA, blocks);
+}
+
+static inline void inode_inc_dirty_pages(struct inode *inode)
+{
+ inode_inc_dirty_pages_nr(inode, 1);
+}
+
+static inline void inode_dec_dirty_pages(struct inode *inode)
+{
+ inode_dec_dirty_pages_nr(inode, 1);
}
static inline void inc_atomic_write_cnt(struct inode *inode)
@@ -4380,6 +4416,7 @@ void f2fs_remove_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino);
int f2fs_recover_orphan_inodes(struct f2fs_sb_info *sbi);
int f2fs_get_valid_checkpoint(struct f2fs_sb_info *sbi);
void f2fs_update_dirty_folio(struct inode *inode, struct folio *folio);
+void f2fs_account_dirty_pages(struct inode *inode, int nr);
void f2fs_remove_dirty_inode(struct inode *inode);
int f2fs_sync_dirty_inodes(struct f2fs_sb_info *sbi, enum inode_type type,
bool from_cp);
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v3 06/17] f2fs: account large folio dirty data at block granularity
2026-10-09 16:12 ` [PATCH v3 06/17] f2fs: account large folio dirty data at block granularity Nanzhe Zhao
@ 2026-10-12 6:54 ` Chao Yu
0 siblings, 0 replies; 29+ messages in thread
From: Chao Yu @ 2026-10-12 6:54 UTC (permalink / raw)
To: Nanzhe Zhao, linux-f2fs-devel, Jaegeuk Kim
Cc: chao, Daeho Jeong, Barry Song, Juan Yescas, Dev Jain,
linux-kernel, David Hildenbrand, Bo Zhang, Kalesh Singh,
Nanzhe Zhao, Pengfei Li, Ryan Roberts
On 10/10/26 00:12, Nanzhe Zhao wrote:
> Originally inode->dirty_pages was accounted once per folio, but f2fs
> needs the counter to be accounted in blocks.
>
> This introduces batch dirty page add/sub accounting; for a large folio
> the changed dirty page count is computed from the dirty bitmap bit
> changes.
>
> Found by f2fs/006 (lfs + checkpoint=disable) and generic/363.
>
> Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
> ---
> fs/f2fs/checkpoint.c | 38 ++++++++++++++++++++++----
> fs/f2fs/data.c | 24 ++++++++++++----
> fs/f2fs/f2fs.h | 65 ++++++++++++++++++++++++++++++++++----------
> 3 files changed, 101 insertions(+), 26 deletions(-)
>
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index 81c1c2de936f..49075c840c61 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -1316,20 +1316,46 @@ static void __remove_dirty_inode(struct inode *inode, enum inode_type type)
> stat_dec_dirty_inode(F2FS_I_SB(inode), type);
> }
>
> -void f2fs_update_dirty_folio(struct inode *inode, struct folio *folio)
> +/*
> + * Account @nr dirty pages (negative when dirtiness is cleared) for @inode.
> + */
> +void f2fs_account_dirty_pages(struct inode *inode, int nr)
How about f2fs_account_dirty_blocks() to match your commit title?
> {
> struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> enum inode_type type = S_ISDIR(inode->i_mode) ? DIR_INODE : FILE_INODE;
>
> - if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode) &&
> - !S_ISLNK(inode->i_mode))
> + if (!nr)
> return;
>
> spin_lock(&sbi->inode_lock[type]);
> - if (type != FILE_INODE || test_opt(sbi, DATA_FLUSH))
> - __add_dirty_inode(inode, type);
> - inode_inc_dirty_pages(inode);
> + if (nr > 0) {
> + if (type != FILE_INODE || test_opt(sbi, DATA_FLUSH))
> + __add_dirty_inode(inode, type);
> + inode_inc_dirty_pages_nr(inode, nr);
> + } else {
> + inode_dec_dirty_pages_nr(inode, -nr);
> + __remove_dirty_inode(inode, type);
> + }
> spin_unlock(&sbi->inode_lock[type]);
> +}
> +
> +void f2fs_update_dirty_folio(struct inode *inode, struct folio *folio)
> +{
> + if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode) &&
> + !S_ISLNK(inode->i_mode))
> + return;
> +
> + /*
> + * Large folios have a subpage dirty bitmap, so defer their dirty accounting
> + * to the f2fs_ffs_*subrange_dirty*() helpers. This avoids nesting
> + * ffs->state_lock with the inode dirty list lock.
> + */
> + if (f2fs_folio_has_ffs(folio)) {
> + folio_set_f2fs_reference(folio);
> + return;
> + }
> +
> + f2fs_account_dirty_pages(inode, 1);
>
> folio_set_f2fs_reference(folio);
> }
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index da388ed9cccc..d45fbe0db161 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -2902,6 +2902,7 @@ void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
> size_t offset, size_t len)
> {
> struct f2fs_folio_state *ffs;
> + unsigned int set;
> unsigned long flags;
>
> f2fs_bug_on(F2FS_F_SB(folio), offset + len > folio_size(folio));
> @@ -2912,21 +2913,27 @@ void f2fs_ffs_mark_subrange_dirty(struct folio *folio,
> ffs = (struct f2fs_folio_state *)folio->private;
>
> spin_lock_irqsave(&ffs->state_lock, flags);
> - __ffs_mark_subrange_dirty(folio, ffs, offset, len);
> + set = __ffs_mark_subrange_dirty(folio, ffs, offset, len);
> spin_unlock_irqrestore(&ffs->state_lock, flags);
> +
> + if (set)
> + f2fs_account_dirty_pages(folio->mapping->host, set);
> }
>
> static bool __ffs_clear_subrange_dirty(struct folio *folio,
> - struct f2fs_folio_state *ffs, size_t offset, size_t len)
> + struct f2fs_folio_state *ffs, size_t offset, size_t len,
> + unsigned int *cleared)
> {
> unsigned int nr_subpages = folio_nr_pages(folio);
> - unsigned int start, end;
> + unsigned int start, end, before;
>
> start = offset >> PAGE_SHIFT;
> end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
> end = min(end, nr_subpages);
>
> + before = bitmap_weight(ffs->state, 2 * nr_subpages);
> bitmap_clear(ffs->state, nr_subpages + start, end - start);
> + *cleared = before - bitmap_weight(ffs->state, 2 * nr_subpages);
> return find_next_bit(ffs->state, 2 * nr_subpages, nr_subpages) <
> 2 * nr_subpages;
> }
> @@ -2938,13 +2945,15 @@ static bool __ffs_clear_subrange_dirty(struct folio *folio,
> * @len: byte length of the subrange
> *
> * Clear the dirty bits of the 4K subpages covered by [offset, offset + len),
> - * and return whether the folio still has any dirty subpage left.
> + * account the cleared subpages against the inode dirty counters, and return
> + * whether the folio still has any dirty subpage left.
> */
> bool f2fs_ffs_clear_subrange_dirty_and_test(struct folio *folio, size_t offset,
> size_t len)
> {
> struct f2fs_folio_state *ffs;
> unsigned long flags;
> + unsigned int cleared = 0;
> bool dirty;
>
> if (!f2fs_folio_has_ffs(folio))
> @@ -2952,9 +2961,12 @@ bool f2fs_ffs_clear_subrange_dirty_and_test(struct folio *folio, size_t offset,
>
> ffs = (struct f2fs_folio_state *)folio->private;
> spin_lock_irqsave(&ffs->state_lock, flags);
> - dirty = __ffs_clear_subrange_dirty(folio, ffs, offset, len);
> + dirty = __ffs_clear_subrange_dirty(folio, ffs, offset, len, &cleared);
> spin_unlock_irqrestore(&ffs->state_lock, flags);
>
> + if (cleared)
> + f2fs_account_dirty_pages(folio->mapping->host, -cleared);
> +
> return dirty;
> }
>
> @@ -4319,7 +4331,7 @@ static int f2fs_write_cache_folios(struct address_space *mapping,
> if (f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
> (err ? pos : end_pos) - folio_pos(folio)))
> folio_redirty_for_writepage(wbc, folio);
> - else
> + else if (!f2fs_folio_has_ffs(folio))
> inode_dec_dirty_pages(inode);
>
> if (bias_added) {
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index e14275f98fe7..2cf98f49c876 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -2916,9 +2916,10 @@ static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
> f2fs_i_blocks_write(inode, count, false, true);
> }
>
> -static inline void inc_cache_count(struct f2fs_sb_info *sbi, int count_type)
> +static inline void inc_cache_count_nr(struct f2fs_sb_info *sbi,
add_cache_counts()
> + int count_type, int nr)
> {
> - atomic_inc(&sbi->nr_caches[count_type]);
> + atomic_add(nr, &sbi->nr_caches[count_type]);
>
> if (count_type == F2FS_DIRTY_DENTS ||
> count_type == F2FS_DIRTY_NODES ||
> @@ -2928,31 +2929,66 @@ static inline void inc_cache_count(struct f2fs_sb_info *sbi, int count_type)
> set_sbi_flag(sbi, SBI_IS_DIRTY);
> }
>
> -static inline void inode_inc_dirty_pages(struct inode *inode)
> +static inline void dec_cache_count_nr(struct f2fs_sb_info *sbi,
sub_cache_counts()
> + int count_type, int nr)
> {
> - atomic_inc(&F2FS_I(inode)->dirty_pages);
> - inc_cache_count(F2FS_I_SB(inode), S_ISDIR(inode->i_mode) ?
> - F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA);
> - if (IS_NOQUOTA(inode))
> - inc_cache_count(F2FS_I_SB(inode), F2FS_DIRTY_QDATA);
> + atomic_sub(nr, &sbi->nr_caches[count_type]);
> +}
> +
> +static inline void inc_cache_count(struct f2fs_sb_info *sbi, int count_type)
> +{
> + inc_cache_count_nr(sbi, count_type, 1);
> }
>
> static inline void dec_cache_count(struct f2fs_sb_info *sbi, int count_type)
> {
> - atomic_dec(&sbi->nr_caches[count_type]);
> + dec_cache_count_nr(sbi, count_type, 1);
> }
>
> -static inline void inode_dec_dirty_pages(struct inode *inode)
> +/*
> + * Account @nr dirty pages for @inode; one page is
> + * (PAGE_SIZE >> log_blocksize) filesystem blocks.
> + */
> +static inline void inode_inc_dirty_pages_nr(struct inode *inode, int nr)
inode_add_dirty_blocks()
> +{
> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> + int blocks = nr * (PAGE_SIZE >> sbi->log_blocksize);
> +
if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode) &&
!S_ISLNK(inode->i_mode))
return;
> + atomic_add(blocks, &F2FS_I(inode)->dirty_pages);
> + if (S_ISDIR(inode->i_mode))
> + inc_cache_count_nr(sbi, F2FS_DIRTY_DENTS, blocks);
> + else
> + inc_cache_count_nr(sbi, F2FS_DIRTY_DATA, blocks);
> + if (IS_NOQUOTA(inode))
> + inc_cache_count_nr(sbi, F2FS_DIRTY_QDATA, blocks);
> +}
> +
> +static inline void inode_dec_dirty_pages_nr(struct inode *inode, int nr)
inode_sub_dirty_blocks()
> {
> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> + int blocks = nr * (PAGE_SIZE >> sbi->log_blocksize);
> +
> if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode) &&
> !S_ISLNK(inode->i_mode))
> return;
>
> - atomic_dec(&F2FS_I(inode)->dirty_pages);
> - dec_cache_count(F2FS_I_SB(inode), S_ISDIR(inode->i_mode) ?
> - F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA);
> + atomic_sub(blocks, &F2FS_I(inode)->dirty_pages);
> + if (S_ISDIR(inode->i_mode))
> + dec_cache_count_nr(sbi, F2FS_DIRTY_DENTS, blocks);
> + else
> + dec_cache_count_nr(sbi, F2FS_DIRTY_DATA, blocks);
> if (IS_NOQUOTA(inode))
> - dec_cache_count(F2FS_I_SB(inode), F2FS_DIRTY_QDATA);
> + dec_cache_count_nr(sbi, F2FS_DIRTY_QDATA, blocks);
> +}
> +
> +static inline void inode_inc_dirty_pages(struct inode *inode)
inode_inc_dirty_block()
> +{
> + inode_inc_dirty_pages_nr(inode, 1);
> +}
> +
> +static inline void inode_dec_dirty_pages(struct inode *inode)
inode_dec_dirty_block()
> +{
> + inode_dec_dirty_pages_nr(inode, 1);
> }
>
> static inline void inc_atomic_write_cnt(struct inode *inode)
> @@ -4380,6 +4416,7 @@ void f2fs_remove_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino);
> int f2fs_recover_orphan_inodes(struct f2fs_sb_info *sbi);
> int f2fs_get_valid_checkpoint(struct f2fs_sb_info *sbi);
> void f2fs_update_dirty_folio(struct inode *inode, struct folio *folio);
> +void f2fs_account_dirty_pages(struct inode *inode, int nr);
> void f2fs_remove_dirty_inode(struct inode *inode);
> int f2fs_sync_dirty_inodes(struct f2fs_sb_info *sbi, enum inode_type type,
> bool from_cp);
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v3 07/17] f2fs: remove mappedtodisk flag usage in mmap write path
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (5 preceding siblings ...)
2026-10-09 16:12 ` [PATCH v3 06/17] f2fs: account large folio dirty data at block granularity Nanzhe Zhao
@ 2026-10-09 16:12 ` Nanzhe Zhao
2026-10-09 16:12 ` [PATCH v3 08/17] f2fs: prepare mmap write faults for large folios Nanzhe Zhao
` (9 subsequent siblings)
16 siblings, 0 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:12 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
PG_mappedtodisk was inherited from the nobh/buffer-head era. However,
f2fs has no buffer heads and the flag is no longer meaningful. The only
user of the flag is the "no holes" shortcut in f2fs_vm_page_mkwrite(),
which makes mmap write faults skip:
- zeroing the post-EOF part of the faulted folio,
- marking the folio dirty (mm dirties shared file mappings after
->page_mkwrite() returns, so this one was not noticeable),
- APP_MAPPED_IO iostat and REQ_TIME updates.
Remove this shortcut in f2fs_vm_page_mkwrite() and stop setting it in
f2fs_read_single_page().
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 1 -
fs/f2fs/file.c | 6 ------
2 files changed, 7 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index d45fbe0db161..59f065eed712 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2572,7 +2572,6 @@ static int f2fs_read_single_page(struct inode *inode, struct fsverity_info *vi,
got_it:
if ((map->m_flags & F2FS_MAP_MAPPED)) {
block_nr = map->m_pblk + block_in_file - map->m_lblk;
- folio_set_mappedtodisk(folio);
if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode), block_nr,
DATA_GENERIC_ENHANCE_READ)) {
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index aade9a04d8f3..e7471949faf2 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -218,12 +218,6 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
/* wait for GCed page writeback via generic cache */
f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
- /*
- * check to see if the page is mapped already (no holes)
- */
- if (folio_test_mappedtodisk(folio))
- goto out_sem;
-
/* page is wholly or partially inside EOF */
if (((loff_t)(folio->index + 1) << PAGE_SHIFT) >
i_size_read(inode)) {
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* [PATCH v3 08/17] f2fs: prepare mmap write faults for large folios
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (6 preceding siblings ...)
2026-10-09 16:12 ` [PATCH v3 07/17] f2fs: remove mappedtodisk flag usage in mmap write path Nanzhe Zhao
@ 2026-10-09 16:12 ` Nanzhe Zhao
2026-10-12 7:04 ` Chao Yu
2026-10-09 16:12 ` [PATCH v3 09/17] f2fs: make GC migration large-folio aware Nanzhe Zhao
` (8 subsequent siblings)
16 siblings, 1 reply; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:12 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
Now write protect `mmap` also need to support large folio,
Change `f2fs_vm_page_mkwrite` to achieve that.
Note it currently marks the whole large folio dirty
to avoid data loss which causes write amplification.
Further optimization is welcome.
The folio_zero_segment() in mkwrite is extended to zero the
post-EOF part of the faulted folio for both order-0 and large
folios, so the f2fs_zero_post_eof_page() call that was added
to cover the removed shortcut is no longer needed.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/f2fs.h | 4 ++
fs/f2fs/file.c | 102 ++++++++++++++++++++++++++++++++-----------------
2 files changed, 71 insertions(+), 35 deletions(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 2cf98f49c876..a78c69b6abb0 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4488,6 +4488,10 @@ int f2fs_write_single_data_page(struct folio *folio, int *submitted,
enum iostat_type io_type,
int compr_blocks, bool allow_balance);
bool f2fs_ffs_test_blk_uptodate(const struct folio *folio, pgoff_t index);
+struct f2fs_folio_state *f2fs_ffs_find_or_alloc(struct folio *folio);
+void f2fs_ffs_mark_subrange_dirty(struct folio *folio, size_t offset, size_t len);
+bool f2fs_ffs_clear_subrange_dirty_and_test(struct folio *folio, size_t offset,
+ size_t len);
void f2fs_write_failed(struct inode *inode, loff_t to);
void f2fs_invalidate_folio(struct folio *folio, size_t offset, size_t length);
bool f2fs_release_folio(struct folio *folio, gfp_t wait);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index e7471949faf2..6eb0c8e05b66 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -118,13 +118,48 @@ static vm_fault_t f2fs_filemap_fault(struct vm_fault *vmf)
return ret;
}
+static int f2fs_get_block_mkwrite(struct inode *inode, struct folio *folio,
+ pgoff_t index, bool need_alloc)
+{
+ struct dnode_of_data dn;
+ int err;
+
+ set_new_dnode(&dn, inode, NULL, NULL, 0);
+ if (need_alloc) {
+ err = f2fs_get_block_locked(&dn, index);
+ } else {
+ err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
+ f2fs_put_dnode(&dn);
+ if (f2fs_is_pinned_file(inode) &&
+ !__is_valid_data_blkaddr(dn.data_blkaddr))
+ err = -EIO;
+ }
+
+ if (err)
+ return err;
+
+ f2fs_folio_wait_writeback(folio, false, true);
+
+ /* wait for GCed page writeback via META_MAPPING */
+ f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
+
+ return 0;
+}
+
static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
{
struct folio *folio = page_folio(vmf->page);
struct inode *inode = file_inode(vmf->vma->vm_file);
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
- struct dnode_of_data dn;
bool need_alloc = !f2fs_is_pinned_file(inode);
+ pgoff_t pidx = folio->index + folio_page_idx(folio, vmf->page);
+ loff_t pos = (loff_t)pidx << PAGE_SHIFT;
+ loff_t isize;
+ loff_t folio_start;
+ loff_t valid_end;
+ size_t dirty_len;
+ size_t subpage_off;
+ pgoff_t i, nr;
int err = 0;
vm_fault_t ret;
@@ -161,7 +196,7 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
#ifdef CONFIG_F2FS_FS_COMPRESSION
if (f2fs_compressed_file(inode)) {
- int ret = f2fs_is_compressed_cluster(inode, folio->index);
+ int ret = f2fs_is_compressed_cluster(inode, pidx);
if (ret < 0) {
err = ret;
@@ -179,66 +214,63 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
f2fs_bug_on(sbi, f2fs_has_inline_data(inode));
- err = f2fs_zero_post_eof_page(inode,
- (folio->index + 1) << PAGE_SHIFT, true, false);
- if (err)
- goto out_pagefault;
-
file_update_time(vmf->vma->vm_file);
filemap_invalidate_lock_shared(inode->i_mapping);
folio_lock(folio);
+ isize = i_size_read(inode);
+ folio_start = folio_pos(folio);
+ subpage_off = offset_in_folio(folio, pos);
+ valid_end = min_t(loff_t, folio_start + folio_size(folio), isize);
+ dirty_len = valid_end - folio_start;
+
if (unlikely(folio->mapping != inode->i_mapping ||
- folio_pos(folio) > i_size_read(inode) ||
- !folio_test_uptodate(folio))) {
+ pos >= isize ||
+ !f2fs_ffs_test_blk_uptodate(folio,
+ folio->index + (subpage_off >> PAGE_SHIFT)))) {
folio_unlock(folio);
err = -EFAULT;
goto out_sem;
}
- set_new_dnode(&dn, inode, NULL, NULL, 0);
- if (need_alloc) {
- /* block allocation */
- err = f2fs_get_block_locked(&dn, folio->index);
- } else {
- err = f2fs_get_dnode_of_data(&dn, folio->index, LOOKUP_NODE);
- f2fs_put_dnode(&dn);
- if (f2fs_is_pinned_file(inode) &&
- !__is_valid_data_blkaddr(dn.data_blkaddr))
- err = -EIO;
- }
+ nr = DIV_ROUND_UP(dirty_len, PAGE_SIZE);
- if (err) {
- folio_unlock(folio);
- goto out_sem;
+ for (i = 0; i < nr; i++) {
+ err = f2fs_get_block_mkwrite(inode, folio, folio->index + i,
+ need_alloc);
+ if (err) {
+ folio_unlock(folio);
+ goto out_sem;
+ }
}
- f2fs_folio_wait_writeback(folio, false, true);
-
- /* wait for GCed page writeback via generic cache */
- f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
-
/* page is wholly or partially inside EOF */
- if (((loff_t)(folio->index + 1) << PAGE_SHIFT) >
- i_size_read(inode)) {
- loff_t offset;
+ if (folio_start + folio_size(folio) > isize) {
+ size_t offset = offset_in_folio(folio, isize);
- offset = i_size_read(inode) & ~PAGE_MASK;
folio_zero_segment(folio, offset, folio_size(folio));
}
+
+ if (folio_test_large(folio)) {
+ if (!f2fs_ffs_find_or_alloc(folio)) {
+ folio_unlock(folio);
+ err = -ENOMEM;
+ goto out_sem;
+ }
+ f2fs_ffs_mark_subrange_dirty(folio, 0, dirty_len);
+ }
folio_mark_dirty(folio);
- f2fs_update_iostat(sbi, inode, APP_MAPPED_IO, F2FS_BLKSIZE(sbi));
+ f2fs_update_iostat(sbi, inode, APP_MAPPED_IO, dirty_len);
f2fs_update_time(sbi, REQ_TIME);
out_sem:
filemap_invalidate_unlock_shared(inode->i_mapping);
-out_pagefault:
sb_end_pagefault(inode->i_sb);
out:
ret = vmf_fs_error(err);
- trace_f2fs_vm_page_mkwrite(inode, folio->index, vmf->vma->vm_flags, ret);
+ trace_f2fs_vm_page_mkwrite(inode, pidx, vmf->vma->vm_flags, ret);
return ret;
}
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v3 08/17] f2fs: prepare mmap write faults for large folios
2026-10-09 16:12 ` [PATCH v3 08/17] f2fs: prepare mmap write faults for large folios Nanzhe Zhao
@ 2026-10-12 7:04 ` Chao Yu
0 siblings, 0 replies; 29+ messages in thread
From: Chao Yu @ 2026-10-12 7:04 UTC (permalink / raw)
To: Nanzhe Zhao, linux-f2fs-devel, Jaegeuk Kim
Cc: chao, Daeho Jeong, Barry Song, Juan Yescas, Dev Jain,
linux-kernel, David Hildenbrand, Bo Zhang, Kalesh Singh,
Nanzhe Zhao, Pengfei Li, Ryan Roberts
On 10/10/26 00:12, Nanzhe Zhao wrote:
> Now write protect `mmap` also need to support large folio,
> Change `f2fs_vm_page_mkwrite` to achieve that.
>
> Note it currently marks the whole large folio dirty
> to avoid data loss which causes write amplification.
> Further optimization is welcome.
>
> The folio_zero_segment() in mkwrite is extended to zero the
> post-EOF part of the faulted folio for both order-0 and large
> folios, so the f2fs_zero_post_eof_page() call that was added
> to cover the removed shortcut is no longer needed.
>
> Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
> ---
> fs/f2fs/f2fs.h | 4 ++
> fs/f2fs/file.c | 102 ++++++++++++++++++++++++++++++++-----------------
> 2 files changed, 71 insertions(+), 35 deletions(-)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 2cf98f49c876..a78c69b6abb0 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -4488,6 +4488,10 @@ int f2fs_write_single_data_page(struct folio *folio, int *submitted,
> enum iostat_type io_type,
> int compr_blocks, bool allow_balance);
> bool f2fs_ffs_test_blk_uptodate(const struct folio *folio, pgoff_t index);
> +struct f2fs_folio_state *f2fs_ffs_find_or_alloc(struct folio *folio);
> +void f2fs_ffs_mark_subrange_dirty(struct folio *folio, size_t offset, size_t len);
> +bool f2fs_ffs_clear_subrange_dirty_and_test(struct folio *folio, size_t offset,
> + size_t len);
> void f2fs_write_failed(struct inode *inode, loff_t to);
> void f2fs_invalidate_folio(struct folio *folio, size_t offset, size_t length);
> bool f2fs_release_folio(struct folio *folio, gfp_t wait);
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index e7471949faf2..6eb0c8e05b66 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -118,13 +118,48 @@ static vm_fault_t f2fs_filemap_fault(struct vm_fault *vmf)
> return ret;
> }
>
> +static int f2fs_get_block_mkwrite(struct inode *inode, struct folio *folio,
> + pgoff_t index, bool need_alloc)
> +{
> + struct dnode_of_data dn;
> + int err;
> +
> + set_new_dnode(&dn, inode, NULL, NULL, 0);
> + if (need_alloc) {
> + err = f2fs_get_block_locked(&dn, index);
> + } else {
> + err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
> + f2fs_put_dnode(&dn);
> + if (f2fs_is_pinned_file(inode) &&
> + !__is_valid_data_blkaddr(dn.data_blkaddr))
> + err = -EIO;
> + }
> +
> + if (err)
> + return err;
> +
> + f2fs_folio_wait_writeback(folio, false, true);
> +
> + /* wait for GCed page writeback via META_MAPPING */
> + f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
> +
> + return 0;
> +}
> +
> static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
> {
> struct folio *folio = page_folio(vmf->page);
> struct inode *inode = file_inode(vmf->vma->vm_file);
> struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> - struct dnode_of_data dn;
> bool need_alloc = !f2fs_is_pinned_file(inode);
> + pgoff_t pidx = folio->index + folio_page_idx(folio, vmf->page);
> + loff_t pos = (loff_t)pidx << PAGE_SHIFT;
> + loff_t isize;
> + loff_t folio_start;
> + loff_t valid_end;
> + size_t dirty_len;
> + size_t subpage_off;
> + pgoff_t i, nr;
> int err = 0;
> vm_fault_t ret;
>
> @@ -161,7 +196,7 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
>
> #ifdef CONFIG_F2FS_FS_COMPRESSION
> if (f2fs_compressed_file(inode)) {
> - int ret = f2fs_is_compressed_cluster(inode, folio->index);
> + int ret = f2fs_is_compressed_cluster(inode, pidx);
>
> if (ret < 0) {
> err = ret;
> @@ -179,66 +214,63 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
>
> f2fs_bug_on(sbi, f2fs_has_inline_data(inode));
>
> - err = f2fs_zero_post_eof_page(inode,
> - (folio->index + 1) << PAGE_SHIFT, true, false);
> - if (err)
> - goto out_pagefault;
> -
> file_update_time(vmf->vma->vm_file);
> filemap_invalidate_lock_shared(inode->i_mapping);
>
> folio_lock(folio);
> + isize = i_size_read(inode);
> + folio_start = folio_pos(folio);
> + subpage_off = offset_in_folio(folio, pos);
> + valid_end = min_t(loff_t, folio_start + folio_size(folio), isize);
> + dirty_len = valid_end - folio_start;
> +
> if (unlikely(folio->mapping != inode->i_mapping ||
> - folio_pos(folio) > i_size_read(inode) ||
> - !folio_test_uptodate(folio))) {
> + pos >= isize ||
> + !f2fs_ffs_test_blk_uptodate(folio,
> + folio->index + (subpage_off >> PAGE_SHIFT)))) {
> folio_unlock(folio);
> err = -EFAULT;
> goto out_sem;
> }
>
> - set_new_dnode(&dn, inode, NULL, NULL, 0);
> - if (need_alloc) {
> - /* block allocation */
> - err = f2fs_get_block_locked(&dn, folio->index);
> - } else {
> - err = f2fs_get_dnode_of_data(&dn, folio->index, LOOKUP_NODE);
> - f2fs_put_dnode(&dn);
> - if (f2fs_is_pinned_file(inode) &&
> - !__is_valid_data_blkaddr(dn.data_blkaddr))
> - err = -EIO;
> - }
> + nr = DIV_ROUND_UP(dirty_len, PAGE_SIZE);
>
> - if (err) {
> - folio_unlock(folio);
> - goto out_sem;
> + for (i = 0; i < nr; i++) {
> + err = f2fs_get_block_mkwrite(inode, folio, folio->index + i,
> + need_alloc);
> + if (err) {
> + folio_unlock(folio);
> + goto out_sem;
> + }
> }
>
> - f2fs_folio_wait_writeback(folio, false, true);
> -
> - /* wait for GCed page writeback via generic cache */
> - f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
> -
> /* page is wholly or partially inside EOF */
> - if (((loff_t)(folio->index + 1) << PAGE_SHIFT) >
> - i_size_read(inode)) {
> - loff_t offset;
> + if (folio_start + folio_size(folio) > isize) {
> + size_t offset = offset_in_folio(folio, isize);
>
> - offset = i_size_read(inode) & ~PAGE_MASK;
> folio_zero_segment(folio, offset, folio_size(folio));
> }
> +
> + if (folio_test_large(folio)) {
> + if (!f2fs_ffs_find_or_alloc(folio)) {
Can we call f2fs_ffs_find_or_alloc() after f2fs_convert_inline_inode()? I feel
it's so later to fail due to -ENOMEM.
Thanks,
> + folio_unlock(folio);
> + err = -ENOMEM;
> + goto out_sem;
> + }
> + f2fs_ffs_mark_subrange_dirty(folio, 0, dirty_len);
> + }
> folio_mark_dirty(folio);
>
> - f2fs_update_iostat(sbi, inode, APP_MAPPED_IO, F2FS_BLKSIZE(sbi));
> + f2fs_update_iostat(sbi, inode, APP_MAPPED_IO, dirty_len);
> f2fs_update_time(sbi, REQ_TIME);
>
> out_sem:
> filemap_invalidate_unlock_shared(inode->i_mapping);
> -out_pagefault:
> sb_end_pagefault(inode->i_sb);
> out:
> ret = vmf_fs_error(err);
>
> - trace_f2fs_vm_page_mkwrite(inode, folio->index, vmf->vma->vm_flags, ret);
> + trace_f2fs_vm_page_mkwrite(inode, pidx, vmf->vma->vm_flags, ret);
> return ret;
> }
>
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v3 09/17] f2fs: make GC migration large-folio aware
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (7 preceding siblings ...)
2026-10-09 16:12 ` [PATCH v3 08/17] f2fs: prepare mmap write faults for large folios Nanzhe Zhao
@ 2026-10-09 16:12 ` Nanzhe Zhao
2026-10-09 16:12 ` [PATCH v3 10/17] f2fs: optimize small block size large folio read Nanzhe Zhao
` (7 subsequent siblings)
16 siblings, 0 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:12 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
GC can operate on a 4K block that is cached inside a large folio.
The data lookup helpers therefore need to test and update uptodate
state for the addressed subpage instead of rejecting large folios or
treating the whole folio as the target block.
Let f2fs_get_read_data_folio(), f2fs_find_data_folio(), and
f2fs_get_lock_data_folio() to use subpage uptodate state. Submit
single-block reads at the requested folio offset and zero only the
addressed 4K range for NEW_ADDR.
Also update `move_data_page` to mark, clear, and restore dirty
state for the target subpage, and submit write I/O with the subpage
offset recorded in f2fs_io_info.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 73 ++++++++++++++++++++++++++++++-----------------
fs/f2fs/f2fs.h | 1 +
fs/f2fs/gc.c | 36 ++++++++++++++++++++---
fs/f2fs/segment.c | 2 +-
4 files changed, 81 insertions(+), 31 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 59f065eed712..171b6a38e5cc 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1455,19 +1455,26 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode,
/* This can handle encryption stuffs */
static void f2fs_submit_page_read(struct inode *inode, struct fsverity_info *vi,
- struct folio *folio, block_t blkaddr,
- blk_opf_t op_flags, bool for_write)
+ struct folio *folio, pgoff_t index,
+ block_t blkaddr, blk_opf_t op_flags,
+ bool for_write)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct bio *bio;
+ size_t offset = 0;
- bio = f2fs_grab_read_bio(inode, vi, blkaddr, 1, op_flags, folio->index,
+ if (f2fs_folio_has_ffs(folio)) {
+ offset = offset_in_folio(folio, (loff_t)index << PAGE_SHIFT);
+ f2fs_update_read_folio_pending(folio, 1);
+ }
+
+ bio = f2fs_grab_read_bio(inode, vi, blkaddr, 1, op_flags, index,
for_write);
/* wait for GCed page writeback via generic cache */
f2fs_wait_on_block_writeback(inode, blkaddr);
- if (!bio_add_folio(bio, folio, PAGE_SIZE, 0))
+ if (!bio_add_folio(bio, folio, PAGE_SIZE, offset))
f2fs_bug_on(sbi, 1);
inc_cache_count(sbi, F2FS_RD_DATA);
@@ -1609,20 +1616,16 @@ struct folio *f2fs_get_read_data_folio(struct inode *inode, pgoff_t index,
struct dnode_of_data dn;
struct folio *folio;
int err;
-retry:
+
folio = f2fs_grab_cache_folio(mapping, index, for_write);
if (IS_ERR(folio))
return folio;
if (folio_test_large(folio)) {
- pgoff_t folio_index = mapping_align_index(mapping, index);
- unsigned long nr_pages = folio_nr_pages(folio);
-
- f2fs_folio_put(folio, true);
- invalidate_inode_pages2_range(mapping, folio_index,
- folio_index + nr_pages - 1);
- f2fs_schedule_timeout(DEFAULT_SCHEDULE_TIMEOUT);
- goto retry;
+ if (!f2fs_ffs_find_or_alloc(folio)) {
+ err = -ENOMEM;
+ goto put_err;
+ }
}
if (f2fs_lookup_read_extent_cache_block(inode, index,
@@ -1658,7 +1661,7 @@ struct folio *f2fs_get_read_data_folio(struct inode *inode, pgoff_t index,
goto put_err;
}
got_it:
- if (folio_test_uptodate(folio)) {
+ if (f2fs_ffs_test_blk_uptodate(folio, index)) {
folio_unlock(folio);
return folio;
}
@@ -1671,15 +1674,17 @@ struct folio *f2fs_get_read_data_folio(struct inode *inode, pgoff_t index,
* f2fs_init_inode_metadata.
*/
if (dn.data_blkaddr == NEW_ADDR) {
- folio_zero_segment(folio, 0, folio_size(folio));
- if (!folio_test_uptodate(folio))
- folio_mark_uptodate(folio);
+ size_t offset = offset_in_folio(folio,
+ (loff_t)index << PAGE_SHIFT);
+
+ folio_zero_segment(folio, offset, offset + PAGE_SIZE);
+ f2fs_ffs_mark_subrange_uptodate(folio, offset, PAGE_SIZE);
folio_unlock(folio);
return folio;
}
- f2fs_submit_page_read(inode, f2fs_need_verity(inode, folio->index),
- folio, dn.data_blkaddr, op_flags, for_write);
+ f2fs_submit_page_read(inode, f2fs_need_verity(inode, index),
+ folio, index, dn.data_blkaddr, op_flags, for_write);
return folio;
put_err:
@@ -1696,7 +1701,7 @@ struct folio *f2fs_find_data_folio(struct inode *inode, pgoff_t index,
folio = f2fs_filemap_get_folio(mapping, index, FGP_ACCESSED, 0);
if (IS_ERR(folio))
goto read;
- if (folio_test_uptodate(folio))
+ if (f2fs_ffs_test_blk_uptodate(folio, index))
return folio;
f2fs_folio_put(folio, false);
@@ -1705,11 +1710,11 @@ struct folio *f2fs_find_data_folio(struct inode *inode, pgoff_t index,
if (IS_ERR(folio))
return folio;
- if (folio_test_uptodate(folio))
+ if (f2fs_ffs_test_blk_uptodate(folio, index))
return folio;
folio_wait_locked(folio);
- if (unlikely(!folio_test_uptodate(folio))) {
+ if (unlikely(!f2fs_ffs_test_blk_uptodate(folio, index))) {
f2fs_folio_put(folio, false);
return ERR_PTR(-EIO);
}
@@ -1733,7 +1738,8 @@ struct folio *f2fs_get_lock_data_folio(struct inode *inode, pgoff_t index,
/* wait for read completion */
folio_lock(folio);
- if (unlikely(folio->mapping != mapping || !folio_test_uptodate(folio))) {
+ if (unlikely(folio->mapping != mapping ||
+ !f2fs_ffs_test_blk_uptodate(folio, index))) {
f2fs_folio_put(folio, true);
return ERR_PTR(-EIO);
}
@@ -2882,6 +2888,22 @@ static void f2fs_ffs_mark_subrange_uptodate(struct folio *folio, size_t offset,
folio_mark_uptodate(folio);
}
+bool f2fs_ffs_test_blk_dirty(const struct folio *folio, pgoff_t index)
+{
+ struct f2fs_folio_state *ffs;
+ unsigned int idx, nr_subpages;
+
+ f2fs_bug_on(F2FS_F_SB(folio), !folio_contains(folio, index));
+
+ if (!f2fs_folio_has_ffs(folio))
+ return folio_test_dirty(folio);
+
+ ffs = (struct f2fs_folio_state *)folio->private;
+ nr_subpages = folio_nr_pages(folio);
+ idx = index - folio->index;
+ return test_bit(nr_subpages + idx, ffs->state);
+}
+
static unsigned int __ffs_mark_subrange_dirty(struct folio *folio,
struct f2fs_folio_state *ffs, size_t offset, size_t len)
{
@@ -2968,7 +2990,6 @@ bool f2fs_ffs_clear_subrange_dirty_and_test(struct folio *folio, size_t offset,
return dirty;
}
-
static unsigned int ffs_next_dirty_subpage(struct f2fs_folio_state *ffs,
const struct folio *folio, unsigned int start,
unsigned int end)
@@ -3466,7 +3487,7 @@ bool f2fs_should_update_outplace(struct inode *inode, struct f2fs_io_info *fio)
return true;
if (fio) {
- if (page_private_gcing(fio->page))
+ if (folio_test_f2fs_gcing(fio->folio))
return true;
if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
f2fs_is_checkpointed_data(sbi, fio->old_blkaddr)))
@@ -5047,7 +5068,7 @@ static int f2fs_write_begin(const struct kiocb *iocb,
*/
f2fs_submit_page_read(inode,
NULL, /* can't write to fsverity files */
- folio, blkaddr, 0, true);
+ folio, index, blkaddr, 0, true);
folio_lock(folio);
if (unlikely(folio->mapping != mapping)) {
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a78c69b6abb0..a33aae6656d4 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4489,6 +4489,7 @@ int f2fs_write_single_data_page(struct folio *folio, int *submitted,
int compr_blocks, bool allow_balance);
bool f2fs_ffs_test_blk_uptodate(const struct folio *folio, pgoff_t index);
struct f2fs_folio_state *f2fs_ffs_find_or_alloc(struct folio *folio);
+bool f2fs_ffs_test_blk_dirty(const struct folio *folio, pgoff_t index);
void f2fs_ffs_mark_subrange_dirty(struct folio *folio, size_t offset, size_t len);
bool f2fs_ffs_clear_subrange_dirty_and_test(struct folio *folio, size_t offset,
size_t len);
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 89e50f871b75..eeeda15d8747 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1512,12 +1512,19 @@ static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
unsigned int segno, int off)
{
struct folio *folio;
+ size_t foff = 0;
+ bool large = false;
int err = 0;
folio = f2fs_get_lock_data_folio(inode, bidx, true);
if (IS_ERR(folio))
return PTR_ERR(folio);
+ if (f2fs_folio_has_ffs(folio)) {
+ large = true;
+ foff = offset_in_folio(folio, (loff_t)bidx << PAGE_SHIFT);
+ }
+
if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
err = -ENOENT;
goto out;
@@ -1532,6 +1539,8 @@ static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
err = -EAGAIN;
goto out;
}
+ if (large)
+ f2fs_ffs_mark_subrange_dirty(folio, foff, PAGE_SIZE);
folio_mark_dirty(folio);
folio_set_f2fs_gcing(folio);
} else {
@@ -1544,32 +1553,51 @@ static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
.op_flags = REQ_SYNC,
.old_blkaddr = NULL_ADDR,
.folio = folio,
+ .folio_offset = bidx - folio->index,
+ .folio_blkcnt = 1,
.encrypted_page = NULL,
.need_lock = LOCK_REQ,
.io_type = FS_GC_DATA_IO,
};
- bool is_dirty = folio_test_dirty(folio);
+ struct f2fs_folio_state *ffs = NULL;
+ bool is_dirty = f2fs_ffs_test_blk_dirty(folio, bidx);
retry:
f2fs_folio_wait_writeback(folio, true, true);
+ if (large) {
+ ffs = (struct f2fs_folio_state *)folio->private;
+ f2fs_ffs_mark_subrange_dirty(folio, foff, PAGE_SIZE);
+ }
folio_mark_dirty(folio);
if (folio_clear_dirty_for_io(folio)) {
- inode_dec_dirty_pages(inode);
- f2fs_remove_dirty_inode(inode);
+ if (!large) {
+ inode_dec_dirty_pages(inode);
+ f2fs_remove_dirty_inode(inode);
+ } else if (f2fs_ffs_clear_subrange_dirty_and_test(folio,
+ foff, PAGE_SIZE)) {
+ folio_mark_dirty(folio);
+ }
}
+ if (large)
+ atomic_inc(&ffs->write_pages_pending);
folio_set_f2fs_gcing(folio);
err = f2fs_do_write_data_page(&fio);
if (err) {
folio_clear_f2fs_gcing(folio);
+ if (large)
+ atomic_dec(&ffs->write_pages_pending);
if (err == -ENOMEM) {
memalloc_retry_wait(GFP_NOFS);
goto retry;
}
- if (is_dirty)
+ if (is_dirty) {
+ if (large)
+ f2fs_ffs_mark_subrange_dirty(folio, foff, PAGE_SIZE);
folio_mark_dirty(folio);
+ }
}
}
out:
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index e4b59d990ec6..f7079b5b8efd 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3860,7 +3860,7 @@ static int __get_segment_type_6(struct f2fs_io_info *fio)
if (is_inode_flag_set(inode, FI_ALIGNED_WRITE))
return CURSEG_COLD_DATA_PINNED;
- if (page_private_gcing(fio->page)) {
+ if (folio_test_f2fs_gcing(fio->folio)) {
if (fio->sbi->am.atgc_enabled &&
(fio->io_type == FS_DATA_IO) &&
(fio->sbi->gc_mode != GC_URGENT_HIGH) &&
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* [PATCH v3 10/17] f2fs: optimize small block size large folio read
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (8 preceding siblings ...)
2026-10-09 16:12 ` [PATCH v3 09/17] f2fs: make GC migration large-folio aware Nanzhe Zhao
@ 2026-10-09 16:12 ` Nanzhe Zhao
2026-10-12 7:09 ` Chao Yu
2026-10-09 16:28 ` [PATCH v3 11/17] f2fs: support partial uptodate " Nanzhe Zhao
` (6 subsequent siblings)
16 siblings, 1 reply; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:12 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
The original f2fs_read_data_large_folio() implementation has limited
benefit with a 4KB block size, mainly because updating
read_pages_pending greatly increases the number of spinlock
operations.
Use len_blks to batch read_pages_pending and iostat updates for
contiguous mapped blocks.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 48 ++++++++++++++++++++++++++++++++----------------
1 file changed, 32 insertions(+), 16 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 171b6a38e5cc..6f6f5223951d 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -158,7 +158,7 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
continue;
}
- if (folio_test_large(folio)) {
+ if (f2fs_folio_has_ffs(folio)) {
struct f2fs_folio_state *ffs =
(struct f2fs_folio_state *)folio->private;
@@ -3081,7 +3081,7 @@ static int f2fs_read_data_large_folio(struct inode *inode,
pgoff_t index, offset, next_pgofs = 0;
unsigned max_nr_pages = rac ? readahead_count(rac) :
folio_nr_pages(folio);
- unsigned nrpages;
+ unsigned nrpages, len_blks;
struct f2fs_folio_state *ffs;
int ret = 0;
bool folio_in_bio = false;
@@ -3105,11 +3105,16 @@ static int f2fs_read_data_large_folio(struct inode *inode,
folio_in_bio = false;
index = folio->index;
offset = 0;
- ffs = NULL;
nrpages = folio_nr_pages(folio);
- for (; nrpages; nrpages--, max_nr_pages--, index++, offset++) {
+ for (; nrpages;
+ nrpages -= len_blks, max_nr_pages -= len_blks,
+ index += len_blks, offset += len_blks) {
sector_t block_nr;
+ unsigned int i;
+
+ len_blks = 1;
+
/*
* Map blocks using the previous result first.
*/
@@ -3138,13 +3143,23 @@ static int f2fs_read_data_large_folio(struct inode *inode,
got_it:
if ((map.m_flags & F2FS_MAP_MAPPED)) {
block_nr = map.m_pblk + index - map.m_lblk;
- if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode), block_nr,
+
+ len_blks = min_t(unsigned int, nrpages, max_nr_pages);
+ len_blks = min_t(unsigned int, len_blks,
+ (unsigned int)(map.m_lblk + map.m_len - index));
+
+ for (i = 0; i < len_blks; i++) {
+ if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode),
+ block_nr + i,
DATA_GENERIC_ENHANCE_READ)) {
- ret = -EFSCORRUPTED;
- goto err_out;
+ ret = -EFSCORRUPTED;
+ goto err_out;
+ }
}
+
} else {
size_t page_offset = offset << PAGE_SHIFT;
+
folio_zero_range(folio, page_offset, PAGE_SIZE);
if (vi && !fsverity_verify_blocks(vi, folio, PAGE_SIZE, page_offset)) {
ret = -EIO;
@@ -3154,7 +3169,7 @@ static int f2fs_read_data_large_folio(struct inode *inode,
}
/* We must increment read_pages_pending before possible BIOs submitting
- * to prevent from premature folio_end_read() call on folio
+ * to prevent from premature folio_end_read() call on folio.
*/
if (folio_test_large(folio)) {
ffs = f2fs_ffs_find_or_alloc(folio);
@@ -3164,9 +3179,7 @@ static int f2fs_read_data_large_folio(struct inode *inode,
}
/* set the bitmap to wait */
- spin_lock_irq(&ffs->state_lock);
- ffs->read_pages_pending++;
- spin_unlock_irq(&ffs->state_lock);
+ f2fs_update_read_folio_pending(folio, len_blks);
}
/*
@@ -3190,17 +3203,20 @@ static int f2fs_read_data_large_folio(struct inode *inode,
* If the page is under writeback, we need to wait for
* its completion to see the correct decrypted data.
*/
- f2fs_wait_on_block_writeback(inode, block_nr);
+ for (i = 0; i < len_blks; i++)
+ f2fs_wait_on_block_writeback(inode, block_nr + i);
- if (!bio_add_folio(bio, folio, F2FS_BLKSIZE(F2FS_I_SB(inode)),
+ if (!bio_add_folio(bio, folio,
+ len_blks * F2FS_BLKSIZE(F2FS_I_SB(inode)),
offset << PAGE_SHIFT))
goto submit_and_realloc;
folio_in_bio = true;
- inc_cache_count(F2FS_I_SB(inode), F2FS_RD_DATA);
+ for (i = 0; i < len_blks; i++)
+ inc_cache_count(F2FS_I_SB(inode), F2FS_RD_DATA);
f2fs_update_iostat(F2FS_I_SB(inode), NULL, FS_DATA_READ_IO,
- F2FS_BLKSIZE(F2FS_I_SB(inode)));
- last_block_in_bio = block_nr;
+ len_blks * F2FS_BLKSIZE(F2FS_I_SB(inode)));
+ last_block_in_bio = block_nr + len_blks - 1;
}
trace_f2fs_read_folio(folio, DATA);
err_out:
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v3 10/17] f2fs: optimize small block size large folio read
2026-10-09 16:12 ` [PATCH v3 10/17] f2fs: optimize small block size large folio read Nanzhe Zhao
@ 2026-10-12 7:09 ` Chao Yu
0 siblings, 0 replies; 29+ messages in thread
From: Chao Yu @ 2026-10-12 7:09 UTC (permalink / raw)
To: Nanzhe Zhao, linux-f2fs-devel, Jaegeuk Kim
Cc: chao, Daeho Jeong, Barry Song, Juan Yescas, Dev Jain,
linux-kernel, David Hildenbrand, Bo Zhang, Kalesh Singh,
Nanzhe Zhao, Pengfei Li, Ryan Roberts
On 10/10/26 00:12, Nanzhe Zhao wrote:
> The original f2fs_read_data_large_folio() implementation has limited
> benefit with a 4KB block size, mainly because updating
> read_pages_pending greatly increases the number of spinlock
> operations.
>
> Use len_blks to batch read_pages_pending and iostat updates for
> contiguous mapped blocks.
>
> Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
> ---
> fs/f2fs/data.c | 48 ++++++++++++++++++++++++++++++++----------------
> 1 file changed, 32 insertions(+), 16 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 171b6a38e5cc..6f6f5223951d 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -158,7 +158,7 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
> continue;
> }
>
> - if (folio_test_large(folio)) {
> + if (f2fs_folio_has_ffs(folio)) {
> struct f2fs_folio_state *ffs =
> (struct f2fs_folio_state *)folio->private;
>
> @@ -3081,7 +3081,7 @@ static int f2fs_read_data_large_folio(struct inode *inode,
> pgoff_t index, offset, next_pgofs = 0;
> unsigned max_nr_pages = rac ? readahead_count(rac) :
> folio_nr_pages(folio);
> - unsigned nrpages;
> + unsigned nrpages, len_blks;
> struct f2fs_folio_state *ffs;
> int ret = 0;
> bool folio_in_bio = false;
> @@ -3105,11 +3105,16 @@ static int f2fs_read_data_large_folio(struct inode *inode,
> folio_in_bio = false;
> index = folio->index;
> offset = 0;
> - ffs = NULL;
> nrpages = folio_nr_pages(folio);
>
> - for (; nrpages; nrpages--, max_nr_pages--, index++, offset++) {
> + for (; nrpages;
> + nrpages -= len_blks, max_nr_pages -= len_blks,
> + index += len_blks, offset += len_blks) {
> sector_t block_nr;
> + unsigned int i;
> +
> + len_blks = 1;
> +
> /*
> * Map blocks using the previous result first.
> */
> @@ -3138,13 +3143,23 @@ static int f2fs_read_data_large_folio(struct inode *inode,
> got_it:
> if ((map.m_flags & F2FS_MAP_MAPPED)) {
> block_nr = map.m_pblk + index - map.m_lblk;
> - if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode), block_nr,
> +
> + len_blks = min_t(unsigned int, nrpages, max_nr_pages);
> + len_blks = min_t(unsigned int, len_blks,
> + (unsigned int)(map.m_lblk + map.m_len - index));
> +
> + for (i = 0; i < len_blks; i++) {
> + if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode),
> + block_nr + i,
> DATA_GENERIC_ENHANCE_READ)) {
> - ret = -EFSCORRUPTED;
> - goto err_out;
> + ret = -EFSCORRUPTED;
> + goto err_out;
> + }
> }
> +
> } else {
> size_t page_offset = offset << PAGE_SHIFT;
> +
> folio_zero_range(folio, page_offset, PAGE_SIZE);
> if (vi && !fsverity_verify_blocks(vi, folio, PAGE_SIZE, page_offset)) {
> ret = -EIO;
> @@ -3154,7 +3169,7 @@ static int f2fs_read_data_large_folio(struct inode *inode,
> }
>
> /* We must increment read_pages_pending before possible BIOs submitting
> - * to prevent from premature folio_end_read() call on folio
> + * to prevent from premature folio_end_read() call on folio.
It's not worth to change this line only by adding a "."
> */
> if (folio_test_large(folio)) {
> ffs = f2fs_ffs_find_or_alloc(folio);
> @@ -3164,9 +3179,7 @@ static int f2fs_read_data_large_folio(struct inode *inode,
> }
>
> /* set the bitmap to wait */
> - spin_lock_irq(&ffs->state_lock);
> - ffs->read_pages_pending++;
> - spin_unlock_irq(&ffs->state_lock);
> + f2fs_update_read_folio_pending(folio, len_blks);
> }
>
> /*
> @@ -3190,17 +3203,20 @@ static int f2fs_read_data_large_folio(struct inode *inode,
> * If the page is under writeback, we need to wait for
> * its completion to see the correct decrypted data.
> */
> - f2fs_wait_on_block_writeback(inode, block_nr);
> + for (i = 0; i < len_blks; i++)
> + f2fs_wait_on_block_writeback(inode, block_nr + i);
f2fs_wait_on_block_writeback_range()
>
> - if (!bio_add_folio(bio, folio, F2FS_BLKSIZE(F2FS_I_SB(inode)),
> + if (!bio_add_folio(bio, folio,
> + len_blks * F2FS_BLKSIZE(F2FS_I_SB(inode)),
> offset << PAGE_SHIFT))
> goto submit_and_realloc;
>
> folio_in_bio = true;
> - inc_cache_count(F2FS_I_SB(inode), F2FS_RD_DATA);
> + for (i = 0; i < len_blks; i++)
> + inc_cache_count(F2FS_I_SB(inode), F2FS_RD_DATA);
> f2fs_update_iostat(F2FS_I_SB(inode), NULL, FS_DATA_READ_IO,
> - F2FS_BLKSIZE(F2FS_I_SB(inode)));
> - last_block_in_bio = block_nr;
> + len_blks * F2FS_BLKSIZE(F2FS_I_SB(inode)));
> + last_block_in_bio = block_nr + len_blks - 1;
> }
> trace_f2fs_read_folio(folio, DATA);
> err_out:
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v3 11/17] f2fs: support partial uptodate large folio read
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (9 preceding siblings ...)
2026-10-09 16:12 ` [PATCH v3 10/17] f2fs: optimize small block size large folio read Nanzhe Zhao
@ 2026-10-09 16:28 ` Nanzhe Zhao
2026-10-12 7:18 ` Chao Yu
2026-10-09 16:28 ` [PATCH v3 12/17] f2fs: handle partial truncate of large folio dirty subpages Nanzhe Zhao
` (5 subsequent siblings)
16 siblings, 1 reply; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:28 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
Buffered write can have write bytes smaller than folio
size for cases when folio minimum order is not zero.
This can left partially uptodate folio in page cache.
So we skip uptodate subpage read in read_data_large_folio.
Also mark hole subpage uptodate in uptodate bitmap.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 69 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 6f6f5223951d..21c43019167a 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -148,6 +148,7 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
struct folio *folio = fi.folio;
unsigned nr_pages = fi.length >> PAGE_SHIFT;
bool finished = true;
+ bool uptodate = bio->bi_status == BLK_STS_OK;
if (!folio_test_large(folio) &&
f2fs_is_compressed_page(folio)) {
@@ -163,6 +164,9 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
(struct f2fs_folio_state *)folio->private;
spin_lock_irqsave(&ffs->state_lock, flags);
+ if (bio->bi_status == BLK_STS_OK)
+ uptodate = __ffs_mark_subrange_uptodate(folio, ffs,
+ fi.offset, fi.length);
ffs->read_pages_pending -= nr_pages;
finished = !ffs->read_pages_pending;
spin_unlock_irqrestore(&ffs->state_lock, flags);
@@ -172,7 +176,8 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
dec_cache_count(F2FS_F_SB(folio), F2FS_RD_DATA);
if (finished)
- folio_end_read(folio, bio->bi_status == BLK_STS_OK);
+ folio_end_read(folio,
+ bio->bi_status == BLK_STS_OK && uptodate);
}
if (ctx)
@@ -3071,6 +3076,56 @@ static bool find_next_valid_block(const struct folio *folio,
return false;
}
+static unsigned int ffs_next_uptodate_subpage(struct f2fs_folio_state *ffs,
+ unsigned int start, unsigned int end)
+{
+ return find_next_bit(ffs->state, end + 1, start);
+}
+
+static unsigned int ffs_next_nonuptodate_subpage(struct f2fs_folio_state *ffs,
+ unsigned int start, unsigned int end)
+{
+ return find_next_zero_bit(ffs->state, end + 1, start);
+}
+
+static void f2fs_skip_fully_uptodate_front(struct folio *folio,
+ pgoff_t *index, pgoff_t *offset, unsigned int *nrpages,
+ unsigned int *max_nr_pages)
+{
+ struct f2fs_folio_state *ffs;
+ unsigned int next, skipped;
+
+ if (!f2fs_folio_has_ffs(folio) || !*nrpages)
+ return;
+
+ ffs = (struct f2fs_folio_state *)folio->private;
+ next = ffs_next_nonuptodate_subpage(ffs, *offset,
+ *offset + *nrpages - 1);
+ skipped = next - *offset;
+ if (!skipped)
+ return;
+
+ *index += skipped;
+ *offset += skipped;
+ *nrpages -= skipped;
+ *max_nr_pages -= skipped;
+}
+
+static void f2fs_truncate_read_extent(struct folio *folio, pgoff_t offset,
+ unsigned int *len_blks)
+{
+ struct f2fs_folio_state *ffs;
+ unsigned int next, end;
+
+ if (!f2fs_folio_has_ffs(folio) || *len_blks <= 1)
+ return;
+
+ ffs = (struct f2fs_folio_state *)folio->private;
+ end = offset + *len_blks - 1;
+ next = ffs_next_uptodate_subpage(ffs, offset + 1, end);
+ if (next <= end)
+ *len_blks = next - offset;
+}
static int f2fs_read_data_large_folio(struct inode *inode,
struct fsverity_info *vi,
struct readahead_control *rac, struct folio *folio)
@@ -3115,6 +3170,11 @@ static int f2fs_read_data_large_folio(struct inode *inode,
len_blks = 1;
+ f2fs_skip_fully_uptodate_front(folio, &index, &offset,
+ &nrpages, &max_nr_pages);
+ if (!nrpages)
+ break;
+
/*
* Map blocks using the previous result first.
*/
@@ -3147,6 +3207,7 @@ static int f2fs_read_data_large_folio(struct inode *inode,
len_blks = min_t(unsigned int, nrpages, max_nr_pages);
len_blks = min_t(unsigned int, len_blks,
(unsigned int)(map.m_lblk + map.m_len - index));
+ f2fs_truncate_read_extent(folio, offset, &len_blks);
for (i = 0; i < len_blks; i++) {
if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode),
@@ -3165,6 +3226,13 @@ static int f2fs_read_data_large_folio(struct inode *inode,
ret = -EIO;
goto err_out;
}
+ if (folio_test_large(folio)) {
+ ffs = f2fs_ffs_find_or_alloc(folio);
+ spin_lock_irq(&ffs->state_lock);
+ __ffs_mark_subrange_uptodate(folio, ffs,
+ page_offset, PAGE_SIZE);
+ spin_unlock_irq(&ffs->state_lock);
+ }
continue;
}
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v3 11/17] f2fs: support partial uptodate large folio read
2026-10-09 16:28 ` [PATCH v3 11/17] f2fs: support partial uptodate " Nanzhe Zhao
@ 2026-10-12 7:18 ` Chao Yu
0 siblings, 0 replies; 29+ messages in thread
From: Chao Yu @ 2026-10-12 7:18 UTC (permalink / raw)
To: Nanzhe Zhao, linux-f2fs-devel, Jaegeuk Kim
Cc: chao, Daeho Jeong, Barry Song, Juan Yescas, Dev Jain,
linux-kernel, David Hildenbrand, Bo Zhang, Kalesh Singh,
Nanzhe Zhao, Pengfei Li, Ryan Roberts
On 10/10/26 00:28, Nanzhe Zhao wrote:
> Buffered write can have write bytes smaller than folio
> size for cases when folio minimum order is not zero.
> This can left partially uptodate folio in page cache.
> So we skip uptodate subpage read in read_data_large_folio.
> Also mark hole subpage uptodate in uptodate bitmap.
>
> Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
> ---
> fs/f2fs/data.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 69 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 6f6f5223951d..21c43019167a 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -148,6 +148,7 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
> struct folio *folio = fi.folio;
> unsigned nr_pages = fi.length >> PAGE_SHIFT;
> bool finished = true;
> + bool uptodate = bio->bi_status == BLK_STS_OK;
>
> if (!folio_test_large(folio) &&
> f2fs_is_compressed_page(folio)) {
> @@ -163,6 +164,9 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
> (struct f2fs_folio_state *)folio->private;
>
> spin_lock_irqsave(&ffs->state_lock, flags);
> + if (bio->bi_status == BLK_STS_OK)
> + uptodate = __ffs_mark_subrange_uptodate(folio, ffs,
> + fi.offset, fi.length);
> ffs->read_pages_pending -= nr_pages;
> finished = !ffs->read_pages_pending;
> spin_unlock_irqrestore(&ffs->state_lock, flags);
> @@ -172,7 +176,8 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
> dec_cache_count(F2FS_F_SB(folio), F2FS_RD_DATA);
>
> if (finished)
> - folio_end_read(folio, bio->bi_status == BLK_STS_OK);
> + folio_end_read(folio,
> + bio->bi_status == BLK_STS_OK && uptodate);
Looks weird, can we initial uptodate to true directly? and only update it according
to __ffs_mark_subrange_uptodate(), rather than (bio->bi_status == BLK_STS_OK)?
> }
>
> if (ctx)
> @@ -3071,6 +3076,56 @@ static bool find_next_valid_block(const struct folio *folio,
> return false;
> }
>
> +static unsigned int ffs_next_uptodate_subpage(struct f2fs_folio_state *ffs,
> + unsigned int start, unsigned int end)
> +{
> + return find_next_bit(ffs->state, end + 1, start);
> +}
> +
> +static unsigned int ffs_next_nonuptodate_subpage(struct f2fs_folio_state *ffs,
> + unsigned int start, unsigned int end)
> +{
> + return find_next_zero_bit(ffs->state, end + 1, start);
> +}
> +
> +static void f2fs_skip_fully_uptodate_front(struct folio *folio,
> + pgoff_t *index, pgoff_t *offset, unsigned int *nrpages,
> + unsigned int *max_nr_pages)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned int next, skipped;
> +
> + if (!f2fs_folio_has_ffs(folio) || !*nrpages)
> + return;
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> + next = ffs_next_nonuptodate_subpage(ffs, *offset,
> + *offset + *nrpages - 1);
> + skipped = next - *offset;
> + if (!skipped)
> + return;
> +
> + *index += skipped;
> + *offset += skipped;
> + *nrpages -= skipped;
> + *max_nr_pages -= skipped;
> +}
> +
> +static void f2fs_truncate_read_extent(struct folio *folio, pgoff_t offset,
> + unsigned int *len_blks)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned int next, end;
> +
> + if (!f2fs_folio_has_ffs(folio) || *len_blks <= 1)
> + return;
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> + end = offset + *len_blks - 1;
> + next = ffs_next_uptodate_subpage(ffs, offset + 1, end);
> + if (next <= end)
> + *len_blks = next - offset;
> +}
Blank line.
Thanks,
> static int f2fs_read_data_large_folio(struct inode *inode,
> struct fsverity_info *vi,
> struct readahead_control *rac, struct folio *folio)
> @@ -3115,6 +3170,11 @@ static int f2fs_read_data_large_folio(struct inode *inode,
>
> len_blks = 1;
>
> + f2fs_skip_fully_uptodate_front(folio, &index, &offset,
> + &nrpages, &max_nr_pages);
> + if (!nrpages)
> + break;
> +
> /*
> * Map blocks using the previous result first.
> */
> @@ -3147,6 +3207,7 @@ static int f2fs_read_data_large_folio(struct inode *inode,
> len_blks = min_t(unsigned int, nrpages, max_nr_pages);
> len_blks = min_t(unsigned int, len_blks,
> (unsigned int)(map.m_lblk + map.m_len - index));
> + f2fs_truncate_read_extent(folio, offset, &len_blks);
>
> for (i = 0; i < len_blks; i++) {
> if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode),
> @@ -3165,6 +3226,13 @@ static int f2fs_read_data_large_folio(struct inode *inode,
> ret = -EIO;
> goto err_out;
> }
> + if (folio_test_large(folio)) {
> + ffs = f2fs_ffs_find_or_alloc(folio);
> + spin_lock_irq(&ffs->state_lock);
> + __ffs_mark_subrange_uptodate(folio, ffs,
> + page_offset, PAGE_SIZE);
> + spin_unlock_irq(&ffs->state_lock);
> + }
> continue;
> }
>
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v3 12/17] f2fs: handle partial truncate of large folio dirty subpages
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (10 preceding siblings ...)
2026-10-09 16:28 ` [PATCH v3 11/17] f2fs: support partial uptodate " Nanzhe Zhao
@ 2026-10-09 16:28 ` Nanzhe Zhao
2026-10-09 18:14 ` [f2fs-dev] " Daeho Jeong
2026-10-12 7:27 ` Chao Yu
2026-10-09 16:28 ` [PATCH v3 13/17] f2fs: wait for folio writeback before ffs_detach_free Nanzhe Zhao
` (4 subsequent siblings)
16 siblings, 2 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:28 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
A large folio can be partial truncated and stays in folio mapping, we
need to clear the subrange dirty bits and uptodate bits that the partial
truncate covers. If this partial truncate happens to clear the last
subrange dirty bits, then cancel the whole folio dirty state.
Also add a guard in f2fs_write_single_data_folio() so a large folio
subpage whose disk block was already truncated (NULL_ADDR) is skipped
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 109 insertions(+), 6 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 21c43019167a..138a77044e95 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -329,6 +329,27 @@ static void f2fs_read_end_io(struct bio *bio)
f2fs_verify_and_finish_bio(bio, intask);
}
+static bool f2fs_ffs_has_dirty_subpage(struct folio *folio)
+{
+ struct f2fs_folio_state *ffs;
+ unsigned long flags;
+ unsigned int nr_subpages;
+ bool dirty;
+
+ if (!f2fs_folio_has_ffs(folio))
+ return false;
+
+ ffs = (struct f2fs_folio_state *)folio->private;
+ nr_subpages = folio_nr_pages(folio);
+
+ spin_lock_irqsave(&ffs->state_lock, flags);
+ dirty = find_next_bit(ffs->state, 2 * nr_subpages,
+ nr_subpages) < 2 * nr_subpages;
+ spin_unlock_irqrestore(&ffs->state_lock, flags);
+
+ return dirty;
+}
+
static void f2fs_write_end_bio(struct bio *bio)
{
struct f2fs_sb_info *sbi = bio->bi_private;
@@ -380,7 +401,8 @@ static void f2fs_write_end_bio(struct bio *bio)
wake_up(&sbi->cp_wait);
if (finished) {
- folio_clear_f2fs_gcing(folio);
+ if (!f2fs_ffs_has_dirty_subpage(folio))
+ folio_clear_f2fs_gcing(folio);
folio_end_writeback(folio);
}
}
@@ -2893,6 +2915,29 @@ static void f2fs_ffs_mark_subrange_uptodate(struct folio *folio, size_t offset,
folio_mark_uptodate(folio);
}
+static void ffs_clear_subrange_uptodate(struct folio *folio,
+ size_t offset, size_t len)
+{
+ struct f2fs_folio_state *ffs;
+ unsigned int nr_subpages, start, end;
+ unsigned long flags;
+
+ f2fs_bug_on(F2FS_F_SB(folio), offset + len > folio_size(folio));
+
+ if (!f2fs_folio_has_ffs(folio))
+ return;
+
+ ffs = (struct f2fs_folio_state *)folio->private;
+ nr_subpages = folio_nr_pages(folio);
+ start = offset >> PAGE_SHIFT;
+ end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ end = min(end, nr_subpages);
+
+ spin_lock_irqsave(&ffs->state_lock, flags);
+ bitmap_clear(ffs->state, start, end - start);
+ spin_unlock_irqrestore(&ffs->state_lock, flags);
+}
+
bool f2fs_ffs_test_blk_dirty(const struct folio *folio, pgoff_t index)
{
struct f2fs_folio_state *ffs;
@@ -3771,12 +3816,35 @@ static int f2fs_write_folio_dirty_range(struct folio *folio, int *submitted,
err = f2fs_get_dnode_of_data(&dn, data_idx, LOOKUP_NODE);
+ /*
+ * If a subpage of folio for a cow file is dirtied but not
+ * reserve a cow block, fallback to original inode to lookup
+ * block address
+ */
+ if (atomic_commit && (err == -ENOENT ||
+ (!err && dn.data_blkaddr == NULL_ADDR))) {
+ f2fs_put_dnode(&dn);
+ set_new_dnode(&dn, inode, NULL, NULL, 0);
+ err = f2fs_get_dnode_of_data(&dn, data_idx,
+ LOOKUP_NODE);
+ /* Original inode has no block, handled as truncated below */
+ if (err == -ENOENT)
+ err = 0;
+ }
if (err)
goto block_done;
dn_held = true;
fio.old_blkaddr = dn.data_blkaddr;
+ /* This page is already truncated */
+ if (fio.old_blkaddr == NULL_ADDR) {
+ ffs_clear_subrange_uptodate(folio,
+ (unsigned long long)i << PAGE_SHIFT,
+ PAGE_SIZE);
+ goto block_done;
+ }
+
got_it:
if (__is_valid_data_blkaddr(fio.old_blkaddr) &&
!f2fs_is_valid_blkaddr(sbi, fio.old_blkaddr,
@@ -4325,6 +4393,7 @@ static int f2fs_write_cache_folios(struct address_space *mapping,
bool verity_in_progress;
int folio_submitted = 0;
bool bias_added = false;
+ bool dirty;
submitted = 0;
next = true;
@@ -4432,15 +4501,19 @@ static int f2fs_write_cache_folios(struct address_space *mapping,
* partially written back), the folio must stay dirty so that
* the remaining subranges are written back later.
*/
- if (f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
- (err ? pos : end_pos) - folio_pos(folio)))
+ dirty = f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
+ (err ? pos : end_pos) - folio_pos(folio));
+ if (dirty)
folio_redirty_for_writepage(wbc, folio);
else if (!f2fs_folio_has_ffs(folio))
inode_dec_dirty_pages(inode);
if (bias_added) {
- if (atomic_dec_and_test(&ffs->write_pages_pending))
+ if (atomic_dec_and_test(&ffs->write_pages_pending)) {
+ if (!dirty)
+ folio_clear_f2fs_gcing(folio);
folio_end_writeback(folio);
+ }
} else if (!folio_submitted && folio_test_writeback(folio)) {
folio_end_writeback(folio);
}
@@ -5243,10 +5316,40 @@ void f2fs_invalidate_folio(struct folio *folio, size_t offset, size_t length)
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
- (offset || length != folio_size(folio)))
+ (offset || length != folio_size(folio))) {
+ size_t clear_start = round_up(offset, PAGE_SIZE);
+ size_t clear_end = round_down(offset + length, PAGE_SIZE);
+ size_t clear_length;
+ bool dirty;
+
+ /*
+ * If the truncated range falls within a single subpage, no
+ * subpage state needs to be cleared.
+ */
+ if (clear_start >= clear_end || !f2fs_folio_has_ffs(folio))
+ return;
+
+ clear_length = clear_end - clear_start;
+ dirty = f2fs_ffs_clear_subrange_dirty_and_test(folio,
+ clear_start, clear_length);
+ ffs_clear_subrange_uptodate(folio, clear_start, clear_length);
+
+ /*
+ * If the truncated subrange happens to clear the remaining
+ * dirty bitmap of the whole folio, cancel the folio-level
+ * dirty state.
+ */
+ if (!dirty && folio_test_dirty(folio))
+ folio_cancel_dirty(folio);
+ if (!dirty && !folio_test_writeback(folio))
+ folio_clear_f2fs_gcing(folio);
return;
+ }
- if (folio_test_dirty(folio)) {
+ if (f2fs_folio_has_ffs(folio)) {
+ f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
+ folio_size(folio));
+ } else if (folio_test_dirty(folio)) {
inode_dec_dirty_pages(inode);
f2fs_remove_dirty_inode(inode);
}
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [f2fs-dev] [PATCH v3 12/17] f2fs: handle partial truncate of large folio dirty subpages
2026-10-09 16:28 ` [PATCH v3 12/17] f2fs: handle partial truncate of large folio dirty subpages Nanzhe Zhao
@ 2026-10-09 18:14 ` Daeho Jeong
2026-10-12 7:27 ` Chao Yu
1 sibling, 0 replies; 29+ messages in thread
From: Daeho Jeong @ 2026-10-09 18:14 UTC (permalink / raw)
To: Nanzhe Zhao
Cc: linux-f2fs-devel, Jaegeuk Kim, Chao Yu, Barry Song, Juan Yescas,
Daeho Jeong, Dev Jain, David Hildenbrand, linux-kernel, Bo Zhang,
Kalesh Singh, Nanzhe Zhao, Pengfei Li, Ryan Roberts
On Fri, Oct 9, 2026 at 9:31 AM Nanzhe Zhao via Linux-f2fs-devel
<linux-f2fs-devel@lists.sourceforge.net> wrote:
>
> A large folio can be partial truncated and stays in folio mapping, we
> need to clear the subrange dirty bits and uptodate bits that the partial
> truncate covers. If this partial truncate happens to clear the last
> subrange dirty bits, then cancel the whole folio dirty state.
>
> Also add a guard in f2fs_write_single_data_folio() so a large folio
> subpage whose disk block was already truncated (NULL_ADDR) is skipped
>
> Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
> ---
> fs/f2fs/data.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 109 insertions(+), 6 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 21c43019167a..138a77044e95 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -329,6 +329,27 @@ static void f2fs_read_end_io(struct bio *bio)
> f2fs_verify_and_finish_bio(bio, intask);
> }
>
> +static bool f2fs_ffs_has_dirty_subpage(struct folio *folio)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned long flags;
> + unsigned int nr_subpages;
> + bool dirty;
> +
> + if (!f2fs_folio_has_ffs(folio))
> + return false;
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> + nr_subpages = folio_nr_pages(folio);
> +
> + spin_lock_irqsave(&ffs->state_lock, flags);
> + dirty = find_next_bit(ffs->state, 2 * nr_subpages,
> + nr_subpages) < 2 * nr_subpages;
> + spin_unlock_irqrestore(&ffs->state_lock, flags);
> +
> + return dirty;
> +}
> +
> static void f2fs_write_end_bio(struct bio *bio)
> {
> struct f2fs_sb_info *sbi = bio->bi_private;
> @@ -380,7 +401,8 @@ static void f2fs_write_end_bio(struct bio *bio)
> wake_up(&sbi->cp_wait);
>
> if (finished) {
> - folio_clear_f2fs_gcing(folio);
> + if (!f2fs_ffs_has_dirty_subpage(folio))
> + folio_clear_f2fs_gcing(folio);
> folio_end_writeback(folio);
> }
> }
> @@ -2893,6 +2915,29 @@ static void f2fs_ffs_mark_subrange_uptodate(struct folio *folio, size_t offset,
> folio_mark_uptodate(folio);
> }
>
> +static void ffs_clear_subrange_uptodate(struct folio *folio,
> + size_t offset, size_t len)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned int nr_subpages, start, end;
> + unsigned long flags;
> +
> + f2fs_bug_on(F2FS_F_SB(folio), offset + len > folio_size(folio));
> +
> + if (!f2fs_folio_has_ffs(folio))
> + return;
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> + nr_subpages = folio_nr_pages(folio);
> + start = offset >> PAGE_SHIFT;
> + end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
> + end = min(end, nr_subpages);
> +
> + spin_lock_irqsave(&ffs->state_lock, flags);
> + bitmap_clear(ffs->state, start, end - start);
> + spin_unlock_irqrestore(&ffs->state_lock, flags);
> +}
> +
> bool f2fs_ffs_test_blk_dirty(const struct folio *folio, pgoff_t index)
> {
> struct f2fs_folio_state *ffs;
> @@ -3771,12 +3816,35 @@ static int f2fs_write_folio_dirty_range(struct folio *folio, int *submitted,
>
> err = f2fs_get_dnode_of_data(&dn, data_idx, LOOKUP_NODE);
>
> + /*
> + * If a subpage of folio for a cow file is dirtied but not
> + * reserve a cow block, fallback to original inode to lookup
> + * block address
> + */
> + if (atomic_commit && (err == -ENOENT ||
> + (!err && dn.data_blkaddr == NULL_ADDR))) {
> + f2fs_put_dnode(&dn);
> + set_new_dnode(&dn, inode, NULL, NULL, 0);
> + err = f2fs_get_dnode_of_data(&dn, data_idx,
> + LOOKUP_NODE);
> + /* Original inode has no block, handled as truncated below */
> + if (err == -ENOENT)
> + err = 0;
> + }
> if (err)
> goto block_done;
Hi Nanzhe,
For non-atomic files, -ENOENT from the first f2fs_get_dnode_of_data()
still comes here as an error, so f2fs_write_cache_folios() redirties
the rest of the folio and returns the error.
f2fs_write_single_data_page() does not fail the writeback on -ENOENT.
I asked the same on v2 05/14. Could non-atomic files also handle it
like NULL_ADDR (already truncated)? Something like:
if (err == -ENOENT) {
ffs_clear_subrange_uptodate(folio,
(unsigned long long)i << PAGE_SHIFT,
PAGE_SIZE);
err = 0;
goto block_done;
}
if (err)
goto block_done;
Thanks,
Daeho
> dn_held = true;
>
> fio.old_blkaddr = dn.data_blkaddr;
>
> + /* This page is already truncated */
> + if (fio.old_blkaddr == NULL_ADDR) {
> + ffs_clear_subrange_uptodate(folio,
> + (unsigned long long)i << PAGE_SHIFT,
> + PAGE_SIZE);
> + goto block_done;
> + }
> +
> got_it:
> if (__is_valid_data_blkaddr(fio.old_blkaddr) &&
> !f2fs_is_valid_blkaddr(sbi, fio.old_blkaddr,
> @@ -4325,6 +4393,7 @@ static int f2fs_write_cache_folios(struct address_space *mapping,
> bool verity_in_progress;
> int folio_submitted = 0;
> bool bias_added = false;
> + bool dirty;
>
> submitted = 0;
> next = true;
> @@ -4432,15 +4501,19 @@ static int f2fs_write_cache_folios(struct address_space *mapping,
> * partially written back), the folio must stay dirty so that
> * the remaining subranges are written back later.
> */
> - if (f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
> - (err ? pos : end_pos) - folio_pos(folio)))
> + dirty = f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
> + (err ? pos : end_pos) - folio_pos(folio));
> + if (dirty)
> folio_redirty_for_writepage(wbc, folio);
> else if (!f2fs_folio_has_ffs(folio))
> inode_dec_dirty_pages(inode);
>
> if (bias_added) {
> - if (atomic_dec_and_test(&ffs->write_pages_pending))
> + if (atomic_dec_and_test(&ffs->write_pages_pending)) {
> + if (!dirty)
> + folio_clear_f2fs_gcing(folio);
> folio_end_writeback(folio);
> + }
> } else if (!folio_submitted && folio_test_writeback(folio)) {
> folio_end_writeback(folio);
> }
> @@ -5243,10 +5316,40 @@ void f2fs_invalidate_folio(struct folio *folio, size_t offset, size_t length)
> struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
>
> if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
> - (offset || length != folio_size(folio)))
> + (offset || length != folio_size(folio))) {
> + size_t clear_start = round_up(offset, PAGE_SIZE);
> + size_t clear_end = round_down(offset + length, PAGE_SIZE);
> + size_t clear_length;
> + bool dirty;
> +
> + /*
> + * If the truncated range falls within a single subpage, no
> + * subpage state needs to be cleared.
> + */
> + if (clear_start >= clear_end || !f2fs_folio_has_ffs(folio))
> + return;
> +
> + clear_length = clear_end - clear_start;
> + dirty = f2fs_ffs_clear_subrange_dirty_and_test(folio,
> + clear_start, clear_length);
> + ffs_clear_subrange_uptodate(folio, clear_start, clear_length);
> +
> + /*
> + * If the truncated subrange happens to clear the remaining
> + * dirty bitmap of the whole folio, cancel the folio-level
> + * dirty state.
> + */
> + if (!dirty && folio_test_dirty(folio))
> + folio_cancel_dirty(folio);
> + if (!dirty && !folio_test_writeback(folio))
> + folio_clear_f2fs_gcing(folio);
> return;
> + }
>
> - if (folio_test_dirty(folio)) {
> + if (f2fs_folio_has_ffs(folio)) {
> + f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
> + folio_size(folio));
> + } else if (folio_test_dirty(folio)) {
> inode_dec_dirty_pages(inode);
> f2fs_remove_dirty_inode(inode);
> }
> --
> 2.43.0
>
>
>
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply [flat|nested] 29+ messages in thread* Re: [PATCH v3 12/17] f2fs: handle partial truncate of large folio dirty subpages
2026-10-09 16:28 ` [PATCH v3 12/17] f2fs: handle partial truncate of large folio dirty subpages Nanzhe Zhao
2026-10-09 18:14 ` [f2fs-dev] " Daeho Jeong
@ 2026-10-12 7:27 ` Chao Yu
1 sibling, 0 replies; 29+ messages in thread
From: Chao Yu @ 2026-10-12 7:27 UTC (permalink / raw)
To: Nanzhe Zhao, linux-f2fs-devel, Jaegeuk Kim
Cc: chao, Daeho Jeong, Barry Song, Juan Yescas, Dev Jain,
linux-kernel, David Hildenbrand, Bo Zhang, Kalesh Singh,
Nanzhe Zhao, Pengfei Li, Ryan Roberts
On 10/10/26 00:28, Nanzhe Zhao wrote:
> A large folio can be partial truncated and stays in folio mapping, we
> need to clear the subrange dirty bits and uptodate bits that the partial
> truncate covers. If this partial truncate happens to clear the last
> subrange dirty bits, then cancel the whole folio dirty state.
>
> Also add a guard in f2fs_write_single_data_folio() so a large folio
> subpage whose disk block was already truncated (NULL_ADDR) is skipped
>
> Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
> ---
> fs/f2fs/data.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 109 insertions(+), 6 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 21c43019167a..138a77044e95 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -329,6 +329,27 @@ static void f2fs_read_end_io(struct bio *bio)
> f2fs_verify_and_finish_bio(bio, intask);
> }
>
> +static bool f2fs_ffs_has_dirty_subpage(struct folio *folio)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned long flags;
> + unsigned int nr_subpages;
> + bool dirty;
> +
> + if (!f2fs_folio_has_ffs(folio))
> + return false;
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> + nr_subpages = folio_nr_pages(folio);
> +
> + spin_lock_irqsave(&ffs->state_lock, flags);
> + dirty = find_next_bit(ffs->state, 2 * nr_subpages,
> + nr_subpages) < 2 * nr_subpages;
> + spin_unlock_irqrestore(&ffs->state_lock, flags);
> +
> + return dirty;
> +}
> +
> static void f2fs_write_end_bio(struct bio *bio)
> {
> struct f2fs_sb_info *sbi = bio->bi_private;
> @@ -380,7 +401,8 @@ static void f2fs_write_end_bio(struct bio *bio)
> wake_up(&sbi->cp_wait);
>
> if (finished) {
> - folio_clear_f2fs_gcing(folio);
> + if (!f2fs_ffs_has_dirty_subpage(folio))
> + folio_clear_f2fs_gcing(folio);
> folio_end_writeback(folio);
> }
> }
> @@ -2893,6 +2915,29 @@ static void f2fs_ffs_mark_subrange_uptodate(struct folio *folio, size_t offset,
> folio_mark_uptodate(folio);
> }
>
> +static void ffs_clear_subrange_uptodate(struct folio *folio,
> + size_t offset, size_t len)
> +{
> + struct f2fs_folio_state *ffs;
> + unsigned int nr_subpages, start, end;
> + unsigned long flags;
> +
> + f2fs_bug_on(F2FS_F_SB(folio), offset + len > folio_size(folio));
> +
> + if (!f2fs_folio_has_ffs(folio))
> + return;
> +
> + ffs = (struct f2fs_folio_state *)folio->private;
> + nr_subpages = folio_nr_pages(folio);
> + start = offset >> PAGE_SHIFT;
> + end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
> + end = min(end, nr_subpages);
> +
> + spin_lock_irqsave(&ffs->state_lock, flags);
> + bitmap_clear(ffs->state, start, end - start);
> + spin_unlock_irqrestore(&ffs->state_lock, flags);
> +}
> +
> bool f2fs_ffs_test_blk_dirty(const struct folio *folio, pgoff_t index)
> {
> struct f2fs_folio_state *ffs;
> @@ -3771,12 +3816,35 @@ static int f2fs_write_folio_dirty_range(struct folio *folio, int *submitted,
>
> err = f2fs_get_dnode_of_data(&dn, data_idx, LOOKUP_NODE);
>
> + /*
> + * If a subpage of folio for a cow file is dirtied but not
> + * reserve a cow block, fallback to original inode to lookup
> + * block address
writeback vs truncate on atomic file?
> + */
> + if (atomic_commit && (err == -ENOENT ||
> + (!err && dn.data_blkaddr == NULL_ADDR))) {
> + f2fs_put_dnode(&dn);
> + set_new_dnode(&dn, inode, NULL, NULL, 0);
> + err = f2fs_get_dnode_of_data(&dn, data_idx,
> + LOOKUP_NODE);
> + /* Original inode has no block, handled as truncated below */
> + if (err == -ENOENT)
> + err = 0;
> + }
> if (err)
> goto block_done;
> dn_held = true;
>
> fio.old_blkaddr = dn.data_blkaddr;
>
> + /* This page is already truncated */
> + if (fio.old_blkaddr == NULL_ADDR) {
> + ffs_clear_subrange_uptodate(folio,
> + (unsigned long long)i << PAGE_SHIFT,
(loff_t)i << PAGE_SHIFT,
Thanks,
> + PAGE_SIZE);
> + goto block_done;
> + }
> +
> got_it:
> if (__is_valid_data_blkaddr(fio.old_blkaddr) &&
> !f2fs_is_valid_blkaddr(sbi, fio.old_blkaddr,
> @@ -4325,6 +4393,7 @@ static int f2fs_write_cache_folios(struct address_space *mapping,
> bool verity_in_progress;
> int folio_submitted = 0;
> bool bias_added = false;
> + bool dirty;
>
> submitted = 0;
> next = true;
> @@ -4432,15 +4501,19 @@ static int f2fs_write_cache_folios(struct address_space *mapping,
> * partially written back), the folio must stay dirty so that
> * the remaining subranges are written back later.
> */
> - if (f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
> - (err ? pos : end_pos) - folio_pos(folio)))
> + dirty = f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
> + (err ? pos : end_pos) - folio_pos(folio));
> + if (dirty)
> folio_redirty_for_writepage(wbc, folio);
> else if (!f2fs_folio_has_ffs(folio))
> inode_dec_dirty_pages(inode);
>
> if (bias_added) {
> - if (atomic_dec_and_test(&ffs->write_pages_pending))
> + if (atomic_dec_and_test(&ffs->write_pages_pending)) {
> + if (!dirty)
> + folio_clear_f2fs_gcing(folio);
> folio_end_writeback(folio);
> + }
> } else if (!folio_submitted && folio_test_writeback(folio)) {
> folio_end_writeback(folio);
> }
> @@ -5243,10 +5316,40 @@ void f2fs_invalidate_folio(struct folio *folio, size_t offset, size_t length)
> struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
>
> if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
> - (offset || length != folio_size(folio)))
> + (offset || length != folio_size(folio))) {
> + size_t clear_start = round_up(offset, PAGE_SIZE);
> + size_t clear_end = round_down(offset + length, PAGE_SIZE);
> + size_t clear_length;
> + bool dirty;
> +
> + /*
> + * If the truncated range falls within a single subpage, no
> + * subpage state needs to be cleared.
> + */
> + if (clear_start >= clear_end || !f2fs_folio_has_ffs(folio))
> + return;
> +
> + clear_length = clear_end - clear_start;
> + dirty = f2fs_ffs_clear_subrange_dirty_and_test(folio,
> + clear_start, clear_length);
> + ffs_clear_subrange_uptodate(folio, clear_start, clear_length);
> +
> + /*
> + * If the truncated subrange happens to clear the remaining
> + * dirty bitmap of the whole folio, cancel the folio-level
> + * dirty state.
> + */
> + if (!dirty && folio_test_dirty(folio))
> + folio_cancel_dirty(folio);
> + if (!dirty && !folio_test_writeback(folio))
> + folio_clear_f2fs_gcing(folio);
> return;
> + }
>
> - if (folio_test_dirty(folio)) {
> + if (f2fs_folio_has_ffs(folio)) {
> + f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
> + folio_size(folio));
> + } else if (folio_test_dirty(folio)) {
> inode_dec_dirty_pages(inode);
> f2fs_remove_dirty_inode(inode);
> }
^ permalink raw reply [flat|nested] 29+ messages in thread
* [PATCH v3 13/17] f2fs: wait for folio writeback before ffs_detach_free
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (11 preceding siblings ...)
2026-10-09 16:28 ` [PATCH v3 12/17] f2fs: handle partial truncate of large folio dirty subpages Nanzhe Zhao
@ 2026-10-09 16:28 ` Nanzhe Zhao
2026-10-09 16:28 ` [PATCH v3 14/17] f2fs: fix zeroing paths for large folios Nanzhe Zhao
` (3 subsequent siblings)
16 siblings, 0 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:28 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao, kernel test robot
truncate_inode_pages_range() can invalidate a large folio that is still
under writeback, which can result in the following use-after-free:
CPU0 (writeback) CPU1 (truncate)
---- ----
f2fs_write_cache_folios()
folio_start_writeback(folio)
/* submit bios */
retry_out:
folio_unlock(folio)
/* all bios submitted; folio lock released */
truncate_inode_pages_range()
find_lock_entries() /* locks the folio */
truncate_cleanup_folio(folio)
folio_invalidate(folio, 0, folio_size(folio))
-> f2fs_invalidate_folio(folio, 0,
folio_size(folio))
f2fs_write_end_bio(bio)
ffs = folio->private ffs_detach_free(folio)
folio_detach_private(folio)
kfree(ffs)
atomic_sub_and_test(nr_pages,
&ffs->write_pages_pending) <-- use-after-free
Wait for folio writeback in invalidate_folio, then we can free the
folio state without any other remaining user.
Reported-by: kernel test robot <yi1.lai@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202610081027.b13dcf10-lkp@intel.com
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 138a77044e95..19072fe7dbe5 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -5347,6 +5347,14 @@ void f2fs_invalidate_folio(struct folio *folio, size_t offset, size_t length)
}
if (f2fs_folio_has_ffs(folio)) {
+ /*
+ * The folio may still be under writeback with bios in
+ * completion that need to access f2fs_folio_state. Wait
+ * for the writeback to complete before freeing the state,
+ * otherwise it will result in use-after-free.
+ */
+ folio_wait_writeback(folio);
+
f2fs_ffs_clear_subrange_dirty_and_test(folio, 0,
folio_size(folio));
} else if (folio_test_dirty(folio)) {
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* [PATCH v3 14/17] f2fs: fix zeroing paths for large folios
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (12 preceding siblings ...)
2026-10-09 16:28 ` [PATCH v3 13/17] f2fs: wait for folio writeback before ffs_detach_free Nanzhe Zhao
@ 2026-10-09 16:28 ` Nanzhe Zhao
2026-10-09 16:28 ` [PATCH v3 15/17] f2fs: handle block cloning within the same large folio Nanzhe Zhao
` (2 subsequent siblings)
16 siblings, 0 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:28 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
Several f2fs zeroing paths still use PAGE_SIZE based offsets after
a file mapping can contain large folios. This is fine for order-0
folios, but it zeros the wrong range once the target block is not at
offset 0 in a large folio.
Use offset_in_folio() to translate the file block index to the folio
offset before zeroing data in truncate_partial_data_page(), fill_zero(),
and f2fs_get_new_data_folio().
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 16 ++++++++++++----
fs/f2fs/f2fs.h | 1 +
fs/f2fs/file.c | 21 ++++++++++++++++-----
3 files changed, 29 insertions(+), 9 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 19072fe7dbe5..05267ad91453 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1800,6 +1800,12 @@ struct folio *f2fs_get_new_data_folio(struct inode *inode,
return ERR_PTR(-ENOMEM);
}
+ if (folio_test_large(folio) && !f2fs_ffs_find_or_alloc(folio)) {
+ f2fs_folio_put(folio, true);
+ f2fs_put_cache(ientry, true);
+ return ERR_PTR(-ENOMEM);
+ }
+
set_new_dnode(&dn, inode, ientry, NULL, 0);
err = f2fs_reserve_block(&dn, index);
if (err) {
@@ -1813,9 +1819,11 @@ struct folio *f2fs_get_new_data_folio(struct inode *inode,
goto got_it;
if (dn.data_blkaddr == NEW_ADDR) {
- folio_zero_segment(folio, 0, folio_size(folio));
- if (!folio_test_uptodate(folio))
- folio_mark_uptodate(folio);
+ size_t off = offset_in_folio(folio,
+ (loff_t)index << PAGE_SHIFT);
+
+ folio_zero_segment(folio, off, off + PAGE_SIZE);
+ f2fs_ffs_mark_subrange_uptodate(folio, off, PAGE_SIZE);
} else {
f2fs_folio_put(folio, true);
@@ -2892,7 +2900,7 @@ bool f2fs_ffs_test_blk_uptodate(const struct folio *folio, pgoff_t index)
return test_bit(idx, ffs->state);
}
-static void f2fs_ffs_mark_subrange_uptodate(struct folio *folio, size_t offset,
+void f2fs_ffs_mark_subrange_uptodate(struct folio *folio, size_t offset,
size_t len)
{
struct f2fs_folio_state *ffs;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a33aae6656d4..80b716b58cbd 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4476,6 +4476,7 @@ struct folio *f2fs_get_lock_data_folio(struct inode *inode, pgoff_t index,
bool for_write);
struct folio *f2fs_get_new_data_folio(struct inode *inode,
struct f2fs_cached_block *ientry, pgoff_t index, bool new_i_size);
+void f2fs_ffs_mark_subrange_uptodate(struct folio *folio, size_t offset, size_t len);
int f2fs_do_write_data_page(struct f2fs_io_info *fio);
int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int flag);
int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 6eb0c8e05b66..f3c4241feed5 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -822,12 +822,13 @@ void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count)
static int truncate_partial_data_page(struct inode *inode, u64 from,
bool cache_only)
{
- loff_t offset = from & (PAGE_SIZE - 1);
pgoff_t index = from >> PAGE_SHIFT;
struct address_space *mapping = inode->i_mapping;
struct folio *folio;
+ size_t folio_off;
+ size_t blk_end;
- if (!offset && !cache_only)
+ if (!(from & (PAGE_SIZE - 1)) && !cache_only)
return 0;
if (cache_only) {
@@ -845,12 +846,18 @@ static int truncate_partial_data_page(struct inode *inode, u64 from,
return PTR_ERR(folio) == -ENOENT ? 0 : PTR_ERR(folio);
truncate_out:
f2fs_folio_wait_writeback(folio, true, true);
- folio_zero_segment(folio, offset, folio_size(folio));
+ folio_off = offset_in_folio(folio, from);
+ blk_end = min_t(size_t, round_up(folio_off, PAGE_SIZE),
+ folio_size(folio));
+ folio_zero_segment(folio, folio_off, blk_end);
/* An encrypted inode should have a key and truncate the last page. */
f2fs_bug_on(F2FS_I_SB(inode), cache_only && IS_ENCRYPTED(inode));
- if (!cache_only)
+ if (!cache_only) {
+ f2fs_ffs_mark_subrange_dirty(folio, folio_off,
+ blk_end - folio_off);
folio_mark_dirty(folio);
+ }
f2fs_folio_put(folio, true);
return 0;
}
@@ -1318,6 +1325,7 @@ static int fill_zero(struct inode *inode, pgoff_t index,
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct folio *folio;
struct f2fs_lock_context lc;
+ size_t folio_off;
if (!len)
return 0;
@@ -1332,7 +1340,10 @@ static int fill_zero(struct inode *inode, pgoff_t index,
return PTR_ERR(folio);
f2fs_folio_wait_writeback(folio, true, true);
- folio_zero_range(folio, start, len);
+ folio_off = offset_in_folio(folio,
+ (loff_t)index << PAGE_SHIFT) + start;
+ folio_zero_range(folio, folio_off, len);
+ f2fs_ffs_mark_subrange_dirty(folio, folio_off, len);
folio_mark_dirty(folio);
f2fs_folio_put(folio, true);
return 0;
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* [PATCH v3 15/17] f2fs: handle block cloning within the same large folio
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (13 preceding siblings ...)
2026-10-09 16:28 ` [PATCH v3 14/17] f2fs: fix zeroing paths for large folios Nanzhe Zhao
@ 2026-10-09 16:28 ` Nanzhe Zhao
2026-10-09 16:28 ` [PATCH v3 16/17] f2fs: allow large folio support to writeable files Nanzhe Zhao
2026-10-09 16:28 ` [PATCH v3 17/17] f2fs: make compressed files compatible with large folio Nanzhe Zhao
16 siblings, 0 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:28 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
With large folios, the source and destination block in __clone_blkaddrs()
can belong to the same folio during same-inode operations such as
collapse range and insert range.
In that case, locking the source folio and then looking up the
destination folio can try to lock the same folio again. It also copies
from and to offset 0, which is only correct for order-0 folios.
Detect the same-inode, same-folio case before looking up the destination
folio. Then in this case,we reserve the destination block explicitly.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/file.c | 61 +++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 53 insertions(+), 8 deletions(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index f3c4241feed5..766e0e46e77a 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1583,25 +1583,70 @@ static int __clone_blkaddrs(struct inode *src_inode, struct inode *dst_inode,
f2fs_put_dnode(&dn);
} else {
struct folio *fsrc, *fdst;
+ size_t src_off, dst_off;
+ bool same_folio;
fsrc = f2fs_get_lock_data_folio(src_inode,
src + i, true);
if (IS_ERR(fsrc))
return PTR_ERR(fsrc);
- fdst = f2fs_get_new_data_folio(dst_inode, NULL, dst + i,
- true);
- if (IS_ERR(fdst)) {
- f2fs_folio_put(fsrc, true);
- return PTR_ERR(fdst);
+
+ src_off = offset_in_folio(fsrc,
+ (loff_t)(src + i) << PAGE_SHIFT);
+
+ /*
+ * For same-inode operations (collapse/insert), src and
+ * dst may fall within the same large folio. Detect this
+ * to avoid self-deadlock on folio lock.
+ */
+ same_folio = src_inode == dst_inode &&
+ folio_contains(fsrc, dst + i);
+ if (same_folio) {
+ struct dnode_of_data dn;
+
+ /* Reserve block for dst before copying */
+ set_new_dnode(&dn, dst_inode, NULL, NULL, 0);
+ ret = f2fs_reserve_block(&dn, dst + i);
+ if (ret) {
+ f2fs_folio_put(fsrc, true);
+ return ret;
+ }
+ fdst = fsrc;
+ } else {
+ fdst = f2fs_get_new_data_folio(dst_inode, NULL,
+ dst + i, true);
+ if (IS_ERR(fdst)) {
+ f2fs_folio_put(fsrc, true);
+ return PTR_ERR(fdst);
+ }
}
+ dst_off = offset_in_folio(fdst,
+ (loff_t)(dst + i) << PAGE_SHIFT);
f2fs_folio_wait_writeback(fdst, true, true);
-
- memcpy_folio(fdst, 0, fsrc, 0, PAGE_SIZE);
+ memcpy_folio(fdst, dst_off, fsrc, src_off,
+ PAGE_SIZE);
+ if (folio_test_large(fdst)) {
+ if (!f2fs_ffs_find_or_alloc(fdst)) {
+ f2fs_folio_put(fdst, true);
+ if (!same_folio)
+ f2fs_folio_put(fsrc, true);
+ return -ENOMEM;
+ }
+ f2fs_ffs_mark_subrange_uptodate(fdst,
+ dst_off, PAGE_SIZE);
+ f2fs_ffs_mark_subrange_dirty(fdst, dst_off,
+ PAGE_SIZE);
+ }
folio_mark_dirty(fdst);
+ if (same_folio && i_size_read(dst_inode) <
+ ((loff_t)(dst + i + 1) << PAGE_SHIFT))
+ f2fs_i_size_write(dst_inode,
+ ((loff_t)(dst + i + 1) << PAGE_SHIFT));
folio_set_f2fs_gcing(fdst);
f2fs_folio_put(fdst, true);
- f2fs_folio_put(fsrc, true);
+ if (!same_folio)
+ f2fs_folio_put(fsrc, true);
ret = f2fs_truncate_hole(src_inode,
src + i, src + i + 1);
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* [PATCH v3 16/17] f2fs: allow large folio support to writeable files
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (14 preceding siblings ...)
2026-10-09 16:28 ` [PATCH v3 15/17] f2fs: handle block cloning within the same large folio Nanzhe Zhao
@ 2026-10-09 16:28 ` Nanzhe Zhao
2026-10-09 16:28 ` [PATCH v3 17/17] f2fs: make compressed files compatible with large folio Nanzhe Zhao
16 siblings, 0 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:28 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
Now we make all write path support large folios,
so we open permission to let writeable file set
large folio mapping.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
fs/f2fs/data.c | 2 +-
fs/f2fs/f2fs.h | 17 +++++++++++++++++
fs/f2fs/file.c | 16 ----------------
fs/f2fs/inline.c | 6 ++++++
fs/f2fs/inode.c | 4 +---
fs/f2fs/namei.c | 1 +
6 files changed, 26 insertions(+), 20 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 05267ad91453..18f568f55b4c 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3194,7 +3194,7 @@ static int f2fs_read_data_large_folio(struct inode *inode,
int ret = 0;
bool folio_in_bio = false;
- if (!IS_IMMUTABLE(inode) || f2fs_compressed_file(inode)) {
+ if (f2fs_compressed_file(inode)) {
if (folio)
folio_unlock(folio);
return -EOPNOTSUPP;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 80b716b58cbd..37f932ffbd2d 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -5344,6 +5344,23 @@ static inline bool f2fs_quota_file(struct f2fs_sb_info *sbi, nid_t ino)
return false;
}
+static inline void f2fs_mapping_set_large_folio(struct inode *inode)
+{
+ if (!S_ISREG(inode->i_mode) ||
+ f2fs_compressed_file(inode) ||
+ f2fs_quota_file(F2FS_I_SB(inode), inode->i_ino))
+ return;
+
+ /*
+ * Keep the folio order range at 0 as a transitional step; large
+ * folios will be enabled once the whole write path is audited.
+ */
+ if (IS_IMMUTABLE(inode))
+ mapping_set_folio_min_order(inode->i_mapping, 0);
+ else
+ mapping_set_folio_order_range(inode->i_mapping, 0, 0);
+}
+
static inline bool f2fs_block_unit_discard(struct f2fs_sb_info *sbi)
{
return F2FS_OPTION(sbi).discard_unit == DISCARD_UNIT_BLOCK;
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 766e0e46e77a..6160734f6700 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -163,17 +163,6 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
int err = 0;
vm_fault_t ret;
- /*
- * We only support large folio on the read case.
- * Don't make any dirty pages.
- */
- if (unlikely(IS_IMMUTABLE(inode)) ||
- mapping_large_folio_support(inode->i_mapping)) {
- f2fs_err(sbi, "Not expected: immutable: %d large_folio: %d",
- IS_IMMUTABLE(inode),
- mapping_large_folio_support(inode->i_mapping));
- return VM_FAULT_SIGBUS;
- }
if (is_inode_flag_set(inode, FI_COMPRESS_RELEASED)) {
err = -EIO;
@@ -709,9 +698,6 @@ static int f2fs_file_open(struct inode *inode, struct file *filp)
if (!f2fs_is_compress_backend_ready(inode))
return -EOPNOTSUPP;
- if (mapping_large_folio_support(inode->i_mapping) &&
- filp->f_mode & FMODE_WRITE)
- return -EOPNOTSUPP;
err = fsverity_file_open(inode, filp);
if (err)
@@ -1183,8 +1169,6 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
return -EPERM;
if ((attr->ia_valid & ATTR_SIZE)) {
- if (mapping_large_folio_support(inode->i_mapping))
- return -EOPNOTSUPP;
if (IS_DEVICE_ALIASING(inode))
return -EPERM;
if (!f2fs_is_compress_backend_ready(inode))
diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index ab7537ff7ebd..0013c76f7bca 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -239,6 +239,12 @@ int f2fs_convert_inline_inode(struct inode *inode)
if (IS_ERR(folio))
return PTR_ERR(folio);
+ /*
+ * Inline data is only supported in an order-0 index #0 folio; the
+ * inline write and mmap fault paths never request a larger order.
+ */
+ f2fs_bug_on(sbi, folio_test_large(folio));
+
f2fs_lock_op(sbi, &lc);
ientry = f2fs_get_inode_cache(sbi, inode->i_ino);
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 9164a2b5d9f0..f5a4dac98ef2 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -599,9 +599,7 @@ struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
inode->i_op = &f2fs_file_inode_operations;
inode->i_fop = &f2fs_file_operations;
inode->i_mapping->a_ops = &f2fs_dblock_aops;
- if (IS_IMMUTABLE(inode) && !f2fs_compressed_file(inode) &&
- !f2fs_quota_file(sbi, inode->i_ino))
- mapping_set_folio_min_order(inode->i_mapping, 0);
+ f2fs_mapping_set_large_folio(inode);
} else if (S_ISDIR(inode->i_mode)) {
inode->i_op = &f2fs_dir_inode_operations;
inode->i_fop = &f2fs_dir_operations;
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 38fcea8b72bf..6a1ff631393c 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -341,6 +341,7 @@ static struct inode *f2fs_new_inode(struct mnt_idmap *idmap,
f2fs_set_inode_flags(inode);
f2fs_init_extent_tree(inode);
+ f2fs_mapping_set_large_folio(inode);
trace_f2fs_new_inode(inode, 0);
return inode;
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread* [PATCH v3 17/17] f2fs: make compressed files compatible with large folio
2026-10-09 16:12 [PATCH v3 00/17] f2fs: support & optimize large folios for writable files Nanzhe Zhao
` (15 preceding siblings ...)
2026-10-09 16:28 ` [PATCH v3 16/17] f2fs: allow large folio support to writeable files Nanzhe Zhao
@ 2026-10-09 16:28 ` Nanzhe Zhao
16 siblings, 0 replies; 29+ messages in thread
From: Nanzhe Zhao @ 2026-10-09 16:28 UTC (permalink / raw)
To: linux-f2fs-devel, Jaegeuk Kim, Chao Yu
Cc: Daeho Jeong, Barry Song, Juan Yescas, Dev Jain, linux-kernel,
David Hildenbrand, Bo Zhang, Kalesh Singh, Nanzhe Zhao,
Pengfei Li, Ryan Roberts, Nanzhe Zhao
The compression flag is the hint indicates that the inode can be
compressed, when the inode is using large folio, we expected it keeps
using the large folio read/write paths and its data stays uncompressed
on disk until the inode is evicted and re-read
Let f2fs_write_begin() skip the compression overwrite preparation for
such inodes and remove the compressed-file gate in
f2fs_read_data_large_folio() so the data is simply read/written as
regular blocks.
For the same reason, reject F2FS_IOC_COMPRESS_FILE with -EOPNOTSUPP
once the inode mapping is switched to large folios.
Signed-off-by: Nanzhe Zhao <zhaonanzhe@xiaomi.com>
---
Documentation/filesystems/f2fs.rst | 10 ++++++++++
fs/f2fs/compress.c | 2 ++
fs/f2fs/data.c | 9 ++-------
fs/f2fs/file.c | 7 +++++++
4 files changed, 21 insertions(+), 7 deletions(-)
diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index 771216f45207..b4f436ffd9ac 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -941,6 +941,16 @@ Compression implementation
reserved via ioctl(F2FS_IOC_RESERVE_COMPRESS_BLOCKS) or the file size is
truncated to zero.
+- Compression and large folios are not effective at the same time on a file:
+ a compressed inode does not use large folios, while an inode which is
+ using large folios keeps its data uncompressed on disk. If the compression
+ flag is set on an inode that is already using large folios, the flag works
+ as a hint until the inode is evicted: the inode keeps using the large folio
+ read/write paths, f2fs_write_begin() skips the compression overwrite
+ preparation, and ioctl(F2FS_IOC_COMPRESS_FILE) fails with -EOPNOTSUPP.
+ Once the inode is evicted and read back, it uses order-0 folios again and
+ compression is applied as usual.
+
Compress metadata layout::
[Dnode Structure]
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index c0e39f580993..4f006a32a1b2 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -78,6 +78,8 @@ bool f2fs_is_compressed_page(struct folio *folio)
return false;
if (folio_test_f2fs_nonpointer(folio))
return false;
+ if (f2fs_folio_has_ffs(folio))
+ return false;
f2fs_bug_on(F2FS_F_SB(folio),
*((u32 *)folio->private) != F2FS_COMPRESSED_PAGE_MAGIC);
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 18f568f55b4c..680659f60509 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3194,12 +3194,6 @@ static int f2fs_read_data_large_folio(struct inode *inode,
int ret = 0;
bool folio_in_bio = false;
- if (f2fs_compressed_file(inode)) {
- if (folio)
- folio_unlock(folio);
- return -EOPNOTSUPP;
- }
-
map.m_seg_type = NO_CHECK_TYPE;
if (rac)
@@ -5124,7 +5118,8 @@ static int f2fs_write_begin(const struct kiocb *iocb,
}
#ifdef CONFIG_F2FS_FS_COMPRESSION
- if (f2fs_compressed_file(inode)) {
+ if (f2fs_compressed_file(inode) &&
+ !mapping_large_folio_support(inode->i_mapping)) {
int ret;
struct page *page;
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 6160734f6700..56450d154e05 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4999,6 +4999,13 @@ static int f2fs_ioc_compress_file(struct file *filp)
if (!(filp->f_mode & FMODE_WRITE))
return -EBADF;
+ /*
+ * The mapping is already using large folios, where the data is kept
+ * uncompressed, so refuse to start compressing the file.
+ */
+ if (mapping_large_folio_support(inode->i_mapping))
+ return -EOPNOTSUPP;
+
f2fs_balance_fs(sbi, true);
ret = mnt_want_write_file(filp);
--
2.43.0
^ permalink raw reply [flat|nested] 29+ messages in thread