* [PATCH] f2fs: support resizable tail section and unify pinned allocation
@ 2026-08-24 19:14 Daeho Jeong
2026-08-25 3:16 ` [f2fs-dev] " Chao Yu
0 siblings, 1 reply; 2+ messages in thread
From: Daeho Jeong @ 2026-08-24 19:14 UTC (permalink / raw)
To: linux-kernel, linux-f2fs-devel, kernel-team; +Cc: Daeho Jeong, Sunmin Jeong
From: Daeho Jeong <daehojeong@google.com>
Currently, zoned block devices restrict pinned file allocations to
conventional zones at the beginning of the storage (before
first_seq_zone_segno), triggering range GC when conventional space is
exhausted.
On regular block devices, when preparing for future online filesystem
resizing (e.g. partition shrinking), pinned files must not be allocated
in the tail area that will be truncated, as pinned files cannot be
relocated by GC. Specifying the resizable tail area size (in sections)
allows uniform mount configuration across devices of different storage
capacities.
To support this, introduce a unified `pinned_area_max_secno` boundary
abstraction in `f2fs_sb_info`:
1. Add `-o resizable_tail_secno=%u` mount option to specify the number
of sections at the tail of the filesystem reserved for resizing.
2. In `f2fs_fill_super()`, initialize `sbi->pinned_area_max_secno` as:
min(MAIN_SECS(sbi) - resizable_tail_sec, zoned_max_sec).
3. In `get_new_segment()`, restrict segment allocation for pinned files
(`pinning == true`) to `0 .. sbi->pinned_area_max_secno - 1`. If no
free section is available in the pinned area, return -EAGAIN.
4. In `f2fs_allocate_pinning_section()`, unify the range GC trigger to
run `f2fs_gc_range()` up to `sbi->pinned_area_max_secno` whenever
`sbi->pinned_area_max_secno < MAIN_SECS(sbi)` and allocation
returns -EAGAIN.
5. Expose `/sys/fs/f2fs/<dev>/pinned_area_max_secno` as a read-only
sysfs node.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Sunmin Jeong <s_min.jeong@samsung.com>
---
Documentation/ABI/testing/sysfs-fs-f2fs | 7 +++++
Documentation/filesystems/f2fs.rst | 8 +++++-
fs/f2fs/f2fs.h | 2 ++
fs/f2fs/segment.c | 33 ++++++++++++-----------
fs/f2fs/segment.h | 1 +
fs/f2fs/super.c | 36 +++++++++++++++++++++++++
fs/f2fs/sysfs.c | 2 ++
7 files changed, 72 insertions(+), 17 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 85194e4c7f01..0cebc89799dd 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -1013,3 +1013,10 @@ Description: Every time a write operation completes f2fs_write_end_io() is
the maximum size of a write bio that is completed in atomic
(atc) context. The default value for this attribute is UINT_MAX
which means that this functionality is disabled by default.
+
+What: /sys/fs/f2fs/<disk>/pinned_area_max_secno
+Date: August 2026
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: This is a read-only entry to show the upper bound section number
+ for pinned files. Pinned files will only be allocated within
+ sections 0 to pinned_area_max_secno - 1.
diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index 1a5fd4afe609..a3c3b6948734 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -417,7 +417,13 @@ lookup_mode=%s Control the directory lookup behavior for casefolded
auto F2FS determines the mode based on the
on-disk `SB_ENC_NO_COMPAT_FALLBACK_FL`
flag.
- ================== ========================================
+resizable_tail_secno=%u Control the number of sections at the tail of the
+ filesystem reserved for online resizing. Pinned files
+ will only be allocated within sections 0 to
+ (MAIN_SECS - resizable_tail_secno) - 1. If set to 0
+ (default), there is no tail restriction unless running
+ on a zoned block device where conventional zones are
+ used.
======================== ============================================================
Debugfs Entries
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index b0a9c14de595..16720f1f0a9c 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -255,6 +255,7 @@ struct f2fs_mount_info {
block_t unusable_cap; /* Amount of space allowed to be
* unusable when disabling checkpoint
*/
+ unsigned int resizable_tail_secno; /* number of resizable tail sections */
/* For compression */
unsigned char compress_algorithm; /* algorithm type */
@@ -2005,6 +2006,7 @@ struct f2fs_sb_info {
spinlock_t dev_lock; /* protect dirty_device */
bool aligned_blksize; /* all devices has the same logical blksize */
unsigned int first_seq_zone_segno; /* first segno in sequential zone */
+ unsigned int pinned_area_max_secno; /* upper bound section for pinned files */
unsigned int bggc_io_aware; /* For adjust the BG_GC priority when pending IO */
unsigned int allocate_section_hint; /* the boundary position between devices */
unsigned int allocate_section_policy; /* determine the section writing priority */
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 56decf9c691c..ed6f2947210b 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2877,6 +2877,7 @@ static int get_new_segment(struct f2fs_sb_info *sbi,
unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
unsigned int alloc_policy = sbi->allocate_section_policy;
unsigned int alloc_hint = sbi->allocate_section_hint;
+ unsigned int max_secno = MAIN_SECS(sbi);
bool init = true;
bool looped = false;
int i, devi;
@@ -2908,7 +2909,7 @@ static int get_new_segment(struct f2fs_sb_info *sbi,
*/
if (f2fs_sb_has_blkzoned(sbi)) {
/* Prioritize writing to conventional zones */
- if (sbi->blkzone_alloc_policy == BLKZONE_ALLOC_PRIOR_CONV || pinning)
+ if (sbi->blkzone_alloc_policy == BLKZONE_ALLOC_PRIOR_CONV)
segno = 0;
else
segno = max(sbi->first_seq_zone_segno, *newseg);
@@ -2924,19 +2925,24 @@ static int get_new_segment(struct f2fs_sb_info *sbi,
alloc_hint > MAIN_SECS(sbi))
alloc_hint = MAIN_SECS(sbi);
- if (alloc_policy == ALLOCATE_FORWARD_FROM_HINT &&
- hint < alloc_hint)
+ if (pinning) {
+ max_secno = sbi->pinned_area_max_secno;
+ hint = 0;
+ } else if (alloc_policy == ALLOCATE_FORWARD_FROM_HINT &&
+ hint < alloc_hint) {
hint = alloc_hint;
- else if (alloc_policy == ALLOCATE_FORWARD_WITHIN_HINT &&
- hint >= alloc_hint)
+ } else if (alloc_policy == ALLOCATE_FORWARD_WITHIN_HINT &&
+ hint >= alloc_hint) {
hint = 0;
+ }
find_other_zone:
- secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
+ secno = find_next_zero_bit(free_i->free_secmap, max_secno, hint);
- if (secno >= MAIN_SECS(sbi)) {
+ if (secno >= max_secno) {
if (looped) {
- ret = -ENOSPC;
+ ret = (pinning && has_pinned_area(sbi)) ?
+ -EAGAIN : -ENOSPC;
f2fs_bug_on(sbi, !pinning);
goto out_unlock;
}
@@ -3001,12 +3007,6 @@ static int get_new_segment(struct f2fs_sb_info *sbi,
goto out_unlock;
}
- /* no free section in conventional device or conventional zone */
- if (new_sec && pinning &&
- f2fs_is_sequential_zone_area(sbi, START_BLOCK(sbi, segno))) {
- ret = -EAGAIN;
- goto out_unlock;
- }
__set_inuse(sbi, segno);
*newseg = segno;
out_unlock:
@@ -3472,8 +3472,9 @@ int f2fs_allocate_pinning_section(struct f2fs_sb_info *sbi)
err = f2fs_allocate_new_section(sbi, CURSEG_COLD_DATA_PINNED, false);
f2fs_unlock_op(sbi, &lc);
- if (f2fs_sb_has_blkzoned(sbi) && err == -EAGAIN && gc_required) {
- err = f2fs_gc_range(sbi, 0, sbi->first_seq_zone_segno - 1,
+ if (has_pinned_area(sbi) && err == -EAGAIN && gc_required) {
+ err = f2fs_gc_range(sbi, 0,
+ sbi->pinned_area_max_secno * SEGS_PER_SEC(sbi) - 1,
true, ZONED_PIN_SEC_REQUIRED_COUNT, true);
if (err)
return err;
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index db1079169a23..1dd8a2fa929d 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -43,6 +43,7 @@ static inline void sanity_check_seg_type(struct f2fs_sb_info *sbi,
#define MAIN_SEGS(sbi) (SM_I(sbi)->main_segments)
#define MAIN_SECS(sbi) ((sbi)->total_sections)
+#define has_pinned_area(sbi) ((sbi)->pinned_area_max_secno < MAIN_SECS(sbi))
#define TOTAL_SEGS(sbi) \
(SM_I(sbi) ? SM_I(sbi)->segment_count : \
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 3bdb0f891c35..c1e315282ec6 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -235,6 +235,7 @@ enum {
Opt_jqfmt,
Opt_checkpoint,
Opt_lookup_mode,
+ Opt_resizable_tail_secno,
Opt_err,
};
@@ -366,6 +367,7 @@ static const struct fs_parameter_spec f2fs_param_specs[] = {
fsparam_flag("age_extent_cache", Opt_age_extent_cache),
fsparam_enum("errors", Opt_errors, f2fs_param_errors),
fsparam_enum("lookup_mode", Opt_lookup_mode, f2fs_param_lookup_mode),
+ fsparam_u32("resizable_tail_secno", Opt_resizable_tail_secno),
{}
};
@@ -551,6 +553,17 @@ static inline void adjust_unusable_cap_perc(struct f2fs_sb_info *sbi)
F2FS_OPTION(sbi).unusable_cap_perc);
}
+static inline void adjust_pinned_area_boundary(struct f2fs_sb_info *sbi)
+{
+ sbi->pinned_area_max_secno = MAIN_SECS(sbi);
+ if (f2fs_sb_has_blkzoned(sbi) && sbi->first_seq_zone_segno != NULL_SEGNO)
+ sbi->pinned_area_max_secno = min(sbi->pinned_area_max_secno,
+ GET_SEC_FROM_SEG(sbi, sbi->first_seq_zone_segno));
+ if (F2FS_OPTION(sbi).resizable_tail_secno)
+ sbi->pinned_area_max_secno = min(sbi->pinned_area_max_secno,
+ MAIN_SECS(sbi) - F2FS_OPTION(sbi).resizable_tail_secno);
+}
+
static void init_once(void *foo)
{
struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
@@ -1235,6 +1248,9 @@ static int f2fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
F2FS_CTX_INFO(ctx).lookup_mode = result.uint_32;
ctx->spec_mask |= F2FS_SPEC_lookup_mode;
break;
+ case Opt_resizable_tail_secno:
+ F2FS_CTX_INFO(ctx).resizable_tail_secno = result.uint_32;
+ break;
}
return 0;
}
@@ -1771,6 +1787,12 @@ static void f2fs_apply_options(struct fs_context *fc, struct super_block *sb)
static int f2fs_sanity_check_options(struct f2fs_sb_info *sbi, bool remount)
{
+ if (remount &&
+ F2FS_OPTION(sbi).resizable_tail_secno >= MAIN_SECS(sbi)) {
+ f2fs_err(sbi, "Option resizable_tail_secno is larger than or equal to total sections (%u >= %u)",
+ F2FS_OPTION(sbi).resizable_tail_secno, MAIN_SECS(sbi));
+ return -EINVAL;
+ }
if (f2fs_sb_has_device_alias(sbi) &&
!test_opt(sbi, READ_EXTENT_CACHE)) {
f2fs_err(sbi, "device aliasing requires extent cache");
@@ -2544,6 +2566,10 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
else if (F2FS_OPTION(sbi).lookup_mode == LOOKUP_AUTO)
seq_show_option(seq, "lookup_mode", "auto");
+ if (F2FS_OPTION(sbi).resizable_tail_secno)
+ seq_printf(seq, ",resizable_tail_secno=%u",
+ F2FS_OPTION(sbi).resizable_tail_secno);
+
return 0;
}
@@ -2586,6 +2612,7 @@ static void default_options(struct f2fs_sb_info *sbi, bool remount)
F2FS_OPTION(sbi).bggc_mode = BGGC_MODE_ON;
F2FS_OPTION(sbi).memory_mode = MEMORY_MODE_NORMAL;
F2FS_OPTION(sbi).errors = MOUNT_ERRORS_CONTINUE;
+ F2FS_OPTION(sbi).resizable_tail_secno = 0;
set_opt(sbi, INLINE_XATTR);
set_opt(sbi, INLINE_DATA);
@@ -3045,6 +3072,7 @@ static int __f2fs_remount(struct fs_context *fc, struct super_block *sb)
sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
(test_opt(sbi, POSIX_ACL) ? SB_POSIXACL : 0);
+ adjust_pinned_area_boundary(sbi);
limit_reserve_root(sbi);
fc->sb_flags = (flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
@@ -5287,6 +5315,14 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc)
/* get segno of first zoned block device */
sbi->first_seq_zone_segno = get_first_seq_zone_segno(sbi);
+ if (F2FS_OPTION(sbi).resizable_tail_secno >= MAIN_SECS(sbi)) {
+ f2fs_err(sbi, "Option resizable_tail_secno is larger than or equal to total sections (%u >= %u)",
+ F2FS_OPTION(sbi).resizable_tail_secno, MAIN_SECS(sbi));
+ err = -EINVAL;
+ goto free_nm;
+ }
+ adjust_pinned_area_boundary(sbi);
+
sbi->reserved_pin_section = f2fs_sb_has_blkzoned(sbi) ?
ZONED_PIN_SEC_REQUIRED_COUNT :
GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi));
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 3201e2185fea..811e350a1430 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -1313,6 +1313,7 @@ F2FS_SBI_GENERAL_RW_ATTR(blkzone_alloc_policy);
#endif
F2FS_SBI_GENERAL_RW_ATTR(carve_out);
F2FS_SBI_GENERAL_RW_ATTR(reserved_pin_section);
+F2FS_SBI_GENERAL_RO_ATTR(pinned_area_max_secno);
F2FS_SBI_GENERAL_RW_ATTR(bggc_io_aware);
F2FS_SBI_GENERAL_RW_ATTR(max_lock_elapsed_time);
F2FS_SBI_GENERAL_RW_ATTR(lock_duration_priority);
@@ -1525,6 +1526,7 @@ static struct attribute *f2fs_attrs[] = {
ATTR_LIST(max_read_extent_count),
ATTR_LIST(carve_out),
ATTR_LIST(reserved_pin_section),
+ ATTR_LIST(pinned_area_max_secno),
ATTR_LIST(allocate_section_hint),
ATTR_LIST(allocate_section_policy),
ATTR_LIST(max_lock_elapsed_time),
--
2.55.0.860.g4b6b3295ed-goog
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [f2fs-dev] [PATCH] f2fs: support resizable tail section and unify pinned allocation
2026-08-24 19:14 [PATCH] f2fs: support resizable tail section and unify pinned allocation Daeho Jeong
@ 2026-08-25 3:16 ` Chao Yu
0 siblings, 0 replies; 2+ messages in thread
From: Chao Yu @ 2026-08-25 3:16 UTC (permalink / raw)
To: Daeho Jeong, linux-kernel, linux-f2fs-devel, kernel-team
Cc: chao, Daeho Jeong
On 8/25/26 03:14, Daeho Jeong wrote:
> From: Daeho Jeong <daehojeong@google.com>
>
> Currently, zoned block devices restrict pinned file allocations to
> conventional zones at the beginning of the storage (before
> first_seq_zone_segno), triggering range GC when conventional space is
> exhausted.
>
> On regular block devices, when preparing for future online filesystem
> resizing (e.g. partition shrinking), pinned files must not be allocated
> in the tail area that will be truncated, as pinned files cannot be
> relocated by GC. Specifying the resizable tail area size (in sections)
> allows uniform mount configuration across devices of different storage
> capacities.
>
> To support this, introduce a unified `pinned_area_max_secno` boundary
> abstraction in `f2fs_sb_info`:
> 1. Add `-o resizable_tail_secno=%u` mount option to specify the number
> of sections at the tail of the filesystem reserved for resizing.
> 2. In `f2fs_fill_super()`, initialize `sbi->pinned_area_max_secno` as:
> min(MAIN_SECS(sbi) - resizable_tail_sec, zoned_max_sec).
> 3. In `get_new_segment()`, restrict segment allocation for pinned files
> (`pinning == true`) to `0 .. sbi->pinned_area_max_secno - 1`. If no
> free section is available in the pinned area, return -EAGAIN.
> 4. In `f2fs_allocate_pinning_section()`, unify the range GC trigger to
> run `f2fs_gc_range()` up to `sbi->pinned_area_max_secno` whenever
> `sbi->pinned_area_max_secno < MAIN_SECS(sbi)` and allocation
> returns -EAGAIN.
> 5. Expose `/sys/fs/f2fs/<dev>/pinned_area_max_secno` as a read-only
> sysfs node.
>
> Signed-off-by: Daeho Jeong <daehojeong@google.com>
> Signed-off-by: Sunmin Jeong <s_min.jeong@samsung.com>
> ---
> Documentation/ABI/testing/sysfs-fs-f2fs | 7 +++++
> Documentation/filesystems/f2fs.rst | 8 +++++-
> fs/f2fs/f2fs.h | 2 ++
> fs/f2fs/segment.c | 33 ++++++++++++-----------
> fs/f2fs/segment.h | 1 +
> fs/f2fs/super.c | 36 +++++++++++++++++++++++++
> fs/f2fs/sysfs.c | 2 ++
> 7 files changed, 72 insertions(+), 17 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
> index 85194e4c7f01..0cebc89799dd 100644
> --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> @@ -1013,3 +1013,10 @@ Description: Every time a write operation completes f2fs_write_end_io() is
> the maximum size of a write bio that is completed in atomic
> (atc) context. The default value for this attribute is UINT_MAX
> which means that this functionality is disabled by default.
> +
> +What: /sys/fs/f2fs/<disk>/pinned_area_max_secno
> +Date: August 2026
> +Contact: "Daeho Jeong" <daehojeong@google.com>
> +Description: This is a read-only entry to show the upper bound section number
> + for pinned files. Pinned files will only be allocated within
> + sections 0 to pinned_area_max_secno - 1.
> diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> index 1a5fd4afe609..a3c3b6948734 100644
> --- a/Documentation/filesystems/f2fs.rst
> +++ b/Documentation/filesystems/f2fs.rst
> @@ -417,7 +417,13 @@ lookup_mode=%s Control the directory lookup behavior for casefolded
> auto F2FS determines the mode based on the
> on-disk `SB_ENC_NO_COMPAT_FALLBACK_FL`
> flag.
> - ================== ========================================
> +resizable_tail_secno=%u Control the number of sections at the tail of the
> + filesystem reserved for online resizing. Pinned files
> + will only be allocated within sections 0 to
> + (MAIN_SECS - resizable_tail_secno) - 1. If set to 0
> + (default), there is no tail restriction unless running
> + on a zoned block device where conventional zones are
> + used.
> ======================== ============================================================
>
> Debugfs Entries
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index b0a9c14de595..16720f1f0a9c 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -255,6 +255,7 @@ struct f2fs_mount_info {
> block_t unusable_cap; /* Amount of space allowed to be
> * unusable when disabling checkpoint
> */
> + unsigned int resizable_tail_secno; /* number of resizable tail sections */
>
> /* For compression */
> unsigned char compress_algorithm; /* algorithm type */
> @@ -2005,6 +2006,7 @@ struct f2fs_sb_info {
> spinlock_t dev_lock; /* protect dirty_device */
> bool aligned_blksize; /* all devices has the same logical blksize */
> unsigned int first_seq_zone_segno; /* first segno in sequential zone */
> + unsigned int pinned_area_max_secno; /* upper bound section for pinned files */
> unsigned int bggc_io_aware; /* For adjust the BG_GC priority when pending IO */
> unsigned int allocate_section_hint; /* the boundary position between devices */
> unsigned int allocate_section_policy; /* determine the section writing priority */
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 56decf9c691c..ed6f2947210b 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -2877,6 +2877,7 @@ static int get_new_segment(struct f2fs_sb_info *sbi,
> unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
> unsigned int alloc_policy = sbi->allocate_section_policy;
> unsigned int alloc_hint = sbi->allocate_section_hint;
> + unsigned int max_secno = MAIN_SECS(sbi);
> bool init = true;
> bool looped = false;
> int i, devi;
> @@ -2908,7 +2909,7 @@ static int get_new_segment(struct f2fs_sb_info *sbi,
> */
> if (f2fs_sb_has_blkzoned(sbi)) {
> /* Prioritize writing to conventional zones */
> - if (sbi->blkzone_alloc_policy == BLKZONE_ALLOC_PRIOR_CONV || pinning)
> + if (sbi->blkzone_alloc_policy == BLKZONE_ALLOC_PRIOR_CONV)
> segno = 0;
> else
> segno = max(sbi->first_seq_zone_segno, *newseg);
> @@ -2924,19 +2925,24 @@ static int get_new_segment(struct f2fs_sb_info *sbi,
> alloc_hint > MAIN_SECS(sbi))
> alloc_hint = MAIN_SECS(sbi);
>
> - if (alloc_policy == ALLOCATE_FORWARD_FROM_HINT &&
> - hint < alloc_hint)
> + if (pinning) {
> + max_secno = sbi->pinned_area_max_secno;
> + hint = 0;
> + } else if (alloc_policy == ALLOCATE_FORWARD_FROM_HINT &&
> + hint < alloc_hint) {
> hint = alloc_hint;
> - else if (alloc_policy == ALLOCATE_FORWARD_WITHIN_HINT &&
> - hint >= alloc_hint)
> + } else if (alloc_policy == ALLOCATE_FORWARD_WITHIN_HINT &&
> + hint >= alloc_hint) {
> hint = 0;
> + }
>
> find_other_zone:
> - secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
> + secno = find_next_zero_bit(free_i->free_secmap, max_secno, hint);
>
> - if (secno >= MAIN_SECS(sbi)) {
> + if (secno >= max_secno) {
> if (looped) {
> - ret = -ENOSPC;
> + ret = (pinning && has_pinned_area(sbi)) ?
> + -EAGAIN : -ENOSPC;
> f2fs_bug_on(sbi, !pinning);
> goto out_unlock;
> }
> @@ -3001,12 +3007,6 @@ static int get_new_segment(struct f2fs_sb_info *sbi,
> goto out_unlock;
> }
>
> - /* no free section in conventional device or conventional zone */
> - if (new_sec && pinning &&
> - f2fs_is_sequential_zone_area(sbi, START_BLOCK(sbi, segno))) {
> - ret = -EAGAIN;
> - goto out_unlock;
> - }
> __set_inuse(sbi, segno);
> *newseg = segno;
> out_unlock:
> @@ -3472,8 +3472,9 @@ int f2fs_allocate_pinning_section(struct f2fs_sb_info *sbi)
> err = f2fs_allocate_new_section(sbi, CURSEG_COLD_DATA_PINNED, false);
> f2fs_unlock_op(sbi, &lc);
>
> - if (f2fs_sb_has_blkzoned(sbi) && err == -EAGAIN && gc_required) {
> - err = f2fs_gc_range(sbi, 0, sbi->first_seq_zone_segno - 1,
> + if (has_pinned_area(sbi) && err == -EAGAIN && gc_required) {
> + err = f2fs_gc_range(sbi, 0,
> + sbi->pinned_area_max_secno * SEGS_PER_SEC(sbi) - 1,
> true, ZONED_PIN_SEC_REQUIRED_COUNT, true);
> if (err)
> return err;
> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
> index db1079169a23..1dd8a2fa929d 100644
> --- a/fs/f2fs/segment.h
> +++ b/fs/f2fs/segment.h
> @@ -43,6 +43,7 @@ static inline void sanity_check_seg_type(struct f2fs_sb_info *sbi,
>
> #define MAIN_SEGS(sbi) (SM_I(sbi)->main_segments)
> #define MAIN_SECS(sbi) ((sbi)->total_sections)
> +#define has_pinned_area(sbi) ((sbi)->pinned_area_max_secno < MAIN_SECS(sbi))
Looks more like has_unpinned_area(sbi), since we assign pinned_area_max_secno
w/ MAIN_SECS(sbi) by default, and will decrease it only if there is conv sections
or valid resizable_tail_secno.
>
> #define TOTAL_SEGS(sbi) \
> (SM_I(sbi) ? SM_I(sbi)->segment_count : \
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 3bdb0f891c35..c1e315282ec6 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -235,6 +235,7 @@ enum {
> Opt_jqfmt,
> Opt_checkpoint,
> Opt_lookup_mode,
> + Opt_resizable_tail_secno,
> Opt_err,
> };
>
> @@ -366,6 +367,7 @@ static const struct fs_parameter_spec f2fs_param_specs[] = {
> fsparam_flag("age_extent_cache", Opt_age_extent_cache),
> fsparam_enum("errors", Opt_errors, f2fs_param_errors),
> fsparam_enum("lookup_mode", Opt_lookup_mode, f2fs_param_lookup_mode),
> + fsparam_u32("resizable_tail_secno", Opt_resizable_tail_secno),
> {}
> };
>
> @@ -551,6 +553,17 @@ static inline void adjust_unusable_cap_perc(struct f2fs_sb_info *sbi)
> F2FS_OPTION(sbi).unusable_cap_perc);
> }
>
> +static inline void adjust_pinned_area_boundary(struct f2fs_sb_info *sbi)
> +{
> + sbi->pinned_area_max_secno = MAIN_SECS(sbi);
> + if (f2fs_sb_has_blkzoned(sbi) && sbi->first_seq_zone_segno != NULL_SEGNO)
> + sbi->pinned_area_max_secno = min(sbi->pinned_area_max_secno,
> + GET_SEC_FROM_SEG(sbi, sbi->first_seq_zone_segno));
> + if (F2FS_OPTION(sbi).resizable_tail_secno)
> + sbi->pinned_area_max_secno = min(sbi->pinned_area_max_secno,
> + MAIN_SECS(sbi) - F2FS_OPTION(sbi).resizable_tail_secno);
> +}
> +
> static void init_once(void *foo)
> {
> struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
> @@ -1235,6 +1248,9 @@ static int f2fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
> F2FS_CTX_INFO(ctx).lookup_mode = result.uint_32;
> ctx->spec_mask |= F2FS_SPEC_lookup_mode;
> break;
> + case Opt_resizable_tail_secno:
> + F2FS_CTX_INFO(ctx).resizable_tail_secno = result.uint_32;
> + break;
> }
> return 0;
> }
> @@ -1771,6 +1787,12 @@ static void f2fs_apply_options(struct fs_context *fc, struct super_block *sb)
>
> static int f2fs_sanity_check_options(struct f2fs_sb_info *sbi, bool remount)
> {
> + if (remount &&
> + F2FS_OPTION(sbi).resizable_tail_secno >= MAIN_SECS(sbi)) {
> + f2fs_err(sbi, "Option resizable_tail_secno is larger than or equal to total sections (%u >= %u)",
> + F2FS_OPTION(sbi).resizable_tail_secno, MAIN_SECS(sbi));
> + return -EINVAL;
> + }
> if (f2fs_sb_has_device_alias(sbi) &&
> !test_opt(sbi, READ_EXTENT_CACHE)) {
> f2fs_err(sbi, "device aliasing requires extent cache");
> @@ -2544,6 +2566,10 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> else if (F2FS_OPTION(sbi).lookup_mode == LOOKUP_AUTO)
> seq_show_option(seq, "lookup_mode", "auto");
>
> + if (F2FS_OPTION(sbi).resizable_tail_secno)
> + seq_printf(seq, ",resizable_tail_secno=%u",
> + F2FS_OPTION(sbi).resizable_tail_secno);
> +
> return 0;
> }
>
> @@ -2586,6 +2612,7 @@ static void default_options(struct f2fs_sb_info *sbi, bool remount)
> F2FS_OPTION(sbi).bggc_mode = BGGC_MODE_ON;
> F2FS_OPTION(sbi).memory_mode = MEMORY_MODE_NORMAL;
> F2FS_OPTION(sbi).errors = MOUNT_ERRORS_CONTINUE;
> + F2FS_OPTION(sbi).resizable_tail_secno = 0;
>
> set_opt(sbi, INLINE_XATTR);
> set_opt(sbi, INLINE_DATA);
> @@ -3045,6 +3072,7 @@ static int __f2fs_remount(struct fs_context *fc, struct super_block *sb)
> sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
> (test_opt(sbi, POSIX_ACL) ? SB_POSIXACL : 0);
>
> + adjust_pinned_area_boundary(sbi);
> limit_reserve_root(sbi);
> fc->sb_flags = (flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
>
> @@ -5287,6 +5315,14 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc)
> /* get segno of first zoned block device */
> sbi->first_seq_zone_segno = get_first_seq_zone_segno(sbi);
>
> + if (F2FS_OPTION(sbi).resizable_tail_secno >= MAIN_SECS(sbi)) {
> + f2fs_err(sbi, "Option resizable_tail_secno is larger than or equal to total sections (%u >= %u)",
> + F2FS_OPTION(sbi).resizable_tail_secno, MAIN_SECS(sbi));
> + err = -EINVAL;
> + goto free_nm;
> + }
How about merging this check into the one in f2fs_sanity_check_options()?
Thanks,
> + adjust_pinned_area_boundary(sbi);
> +
> sbi->reserved_pin_section = f2fs_sb_has_blkzoned(sbi) ?
> ZONED_PIN_SEC_REQUIRED_COUNT :
> GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi));
> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> index 3201e2185fea..811e350a1430 100644
> --- a/fs/f2fs/sysfs.c
> +++ b/fs/f2fs/sysfs.c
> @@ -1313,6 +1313,7 @@ F2FS_SBI_GENERAL_RW_ATTR(blkzone_alloc_policy);
> #endif
> F2FS_SBI_GENERAL_RW_ATTR(carve_out);
> F2FS_SBI_GENERAL_RW_ATTR(reserved_pin_section);
> +F2FS_SBI_GENERAL_RO_ATTR(pinned_area_max_secno);
> F2FS_SBI_GENERAL_RW_ATTR(bggc_io_aware);
> F2FS_SBI_GENERAL_RW_ATTR(max_lock_elapsed_time);
> F2FS_SBI_GENERAL_RW_ATTR(lock_duration_priority);
> @@ -1525,6 +1526,7 @@ static struct attribute *f2fs_attrs[] = {
> ATTR_LIST(max_read_extent_count),
> ATTR_LIST(carve_out),
> ATTR_LIST(reserved_pin_section),
> + ATTR_LIST(pinned_area_max_secno),
> ATTR_LIST(allocate_section_hint),
> ATTR_LIST(allocate_section_policy),
> ATTR_LIST(max_lock_elapsed_time),
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-08-25 3:16 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2026-08-24 19:14 [PATCH] f2fs: support resizable tail section and unify pinned allocation Daeho Jeong
2026-08-25 3:16 ` [f2fs-dev] " Chao Yu
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