[PATCH 1/2] f2fs: show precise # of blocks that user/root can use

[PATCH 1/2] f2fs: show precise # of blocks that user/root can use

[Jaegeuk Kim]

Let's show precise # of blocks that user/root can use through bavail and bfree
respectively.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/super.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 0a820ba55b10..4c1c99cf54ef 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1005,9 +1005,9 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_bsize = sbi->blocksize;
 
 	buf->f_blocks = total_count - start_count;
-	buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;
-	buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
+	buf->f_bfree = user_block_count - valid_user_blocks(sbi) -
 						sbi->current_reserved_blocks;
+	buf->f_bavail = buf->f_bfree;
 
 	avail_node_count = sbi->total_node_count - sbi->nquota_files -
 						F2FS_RESERVED_NODE_NUM;
-- 
2.15.0.531.g2ccb3012c9-goog

[PATCH 2/2] f2fs: add reserved blocks for root user

[Jaegeuk Kim]

This patch allows root to reserve some blocks via mount option.

"-o reserve_root=N" means N x 4KB-sized blocks for root only.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/f2fs.h  | 26 ++++++++++++++++++++++----
 fs/f2fs/super.c | 29 ++++++++++++++++++++++++++---
 fs/f2fs/sysfs.c |  3 ++-
 3 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 369607b1e776..fb98b51f7376 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -95,6 +95,7 @@ extern char *fault_name[FAULT_MAX];
 #define F2FS_MOUNT_PRJQUOTA		0x00200000
 #define F2FS_MOUNT_QUOTA		0x00400000
 #define F2FS_MOUNT_INLINE_XATTR_SIZE	0x00800000
+#define F2FS_MOUNT_RESERVE_ROOT		0x01000000
 
 #define clear_opt(sbi, option)	((sbi)->mount_opt.opt &= ~F2FS_MOUNT_##option)
 #define set_opt(sbi, option)	((sbi)->mount_opt.opt |= F2FS_MOUNT_##option)
@@ -1109,6 +1110,7 @@ struct f2fs_sb_info {
 	block_t last_valid_block_count;		/* for recovery */
 	block_t reserved_blocks;		/* configurable reserved blocks */
 	block_t current_reserved_blocks;	/* current reserved blocks */
+	block_t root_reserved_blocks;		/* root reserved blocks */
 
 	unsigned int nquota_files;		/* # of quota sysfile */
 
@@ -1561,6 +1563,12 @@ static inline bool f2fs_has_xattr_block(unsigned int ofs)
 	return ofs == XATTR_NODE_OFFSET;
 }
 
+static inline block_t reserve_root_limit(struct f2fs_sb_info *sbi)
+{
+	/* limit is 0.2% */
+	return (sbi->user_block_count << 1) / 1000;
+}
+
 static inline void f2fs_i_blocks_write(struct inode *, block_t, bool, bool);
 static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
 				 struct inode *inode, blkcnt_t *count)
@@ -1590,11 +1598,17 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
 	sbi->total_valid_block_count += (block_t)(*count);
 	avail_user_block_count = sbi->user_block_count -
 					sbi->current_reserved_blocks;
+
+	if (!(test_opt(sbi, RESERVE_ROOT) && capable(CAP_SYS_RESOURCE)))
+		avail_user_block_count -= sbi->root_reserved_blocks;
+
 	if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {
 		diff = sbi->total_valid_block_count - avail_user_block_count;
+		if (diff > *count)
+			diff = *count;
 		*count -= diff;
 		release = diff;
-		sbi->total_valid_block_count = avail_user_block_count;
+		sbi->total_valid_block_count -= diff;
 		if (!*count) {
 			spin_unlock(&sbi->stat_lock);
 			percpu_counter_sub(&sbi->alloc_valid_block_count, diff);
@@ -1783,9 +1797,13 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi,
 
 	spin_lock(&sbi->stat_lock);
 
-	valid_block_count = sbi->total_valid_block_count + 1;
-	if (unlikely(valid_block_count + sbi->current_reserved_blocks >
-						sbi->user_block_count)) {
+	valid_block_count = sbi->total_valid_block_count +
+					sbi->current_reserved_blocks + 1;
+
+	if (!(test_opt(sbi, RESERVE_ROOT) && capable(CAP_SYS_RESOURCE)))
+		valid_block_count += sbi->root_reserved_blocks;
+
+	if (unlikely(valid_block_count > sbi->user_block_count)) {
 		spin_unlock(&sbi->stat_lock);
 		goto enospc;
 	}
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 4c1c99cf54ef..56b3caeec1ea 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -107,6 +107,7 @@ enum {
 	Opt_noextent_cache,
 	Opt_noinline_data,
 	Opt_data_flush,
+	Opt_reserve_root,
 	Opt_mode,
 	Opt_io_size_bits,
 	Opt_fault_injection,
@@ -157,6 +158,7 @@ static match_table_t f2fs_tokens = {
 	{Opt_noextent_cache, "noextent_cache"},
 	{Opt_noinline_data, "noinline_data"},
 	{Opt_data_flush, "data_flush"},
+	{Opt_reserve_root, "reserve_root=%u"},
 	{Opt_mode, "mode=%s"},
 	{Opt_io_size_bits, "io_bits=%u"},
 	{Opt_fault_injection, "fault_injection=%u"},
@@ -488,6 +490,18 @@ static int parse_options(struct super_block *sb, char *options)
 		case Opt_data_flush:
 			set_opt(sbi, DATA_FLUSH);
 			break;
+		case Opt_reserve_root:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+			if (test_opt(sbi, RESERVE_ROOT)) {
+				f2fs_msg(sb, KERN_INFO,
+					"Preserve previous reserve_root=%u",
+					sbi->root_reserved_blocks);
+			} else {
+				sbi->root_reserved_blocks = arg;
+				set_opt(sbi, RESERVE_ROOT);
+			}
+			break;
 		case Opt_mode:
 			name = match_strdup(&args[0]);
 
@@ -994,20 +1008,19 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	struct super_block *sb = dentry->d_sb;
 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
-	block_t total_count, user_block_count, start_count, ovp_count;
+	block_t total_count, user_block_count, start_count;
 	u64 avail_node_count;
 
 	total_count = le64_to_cpu(sbi->raw_super->block_count);
 	user_block_count = sbi->user_block_count;
 	start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
-	ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
 	buf->f_type = F2FS_SUPER_MAGIC;
 	buf->f_bsize = sbi->blocksize;
 
 	buf->f_blocks = total_count - start_count;
 	buf->f_bfree = user_block_count - valid_user_blocks(sbi) -
 						sbi->current_reserved_blocks;
-	buf->f_bavail = buf->f_bfree;
+	buf->f_bavail = buf->f_bfree - sbi->root_reserved_blocks;
 
 	avail_node_count = sbi->total_node_count - sbi->nquota_files -
 						F2FS_RESERVED_NODE_NUM;
@@ -1136,6 +1149,9 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 	else if (test_opt(sbi, LFS))
 		seq_puts(seq, "lfs");
 	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
+	if (test_opt(sbi, RESERVE_ROOT))
+		seq_printf(seq, ",reserve_root=%u",
+				sbi->root_reserved_blocks);
 	if (F2FS_IO_SIZE_BITS(sbi))
 		seq_printf(seq, ",io_size=%uKB", F2FS_IO_SIZE_KB(sbi));
 #ifdef CONFIG_F2FS_FAULT_INJECTION
@@ -2571,6 +2587,13 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	sbi->reserved_blocks = 0;
 	sbi->current_reserved_blocks = 0;
 
+	if (test_opt(sbi, RESERVE_ROOT) &&
+		sbi->root_reserved_blocks > reserve_root_limit(sbi)) {
+		sbi->root_reserved_blocks = reserve_root_limit(sbi);
+		f2fs_msg(sb, KERN_INFO,
+			"Reduce reserved blocks for root = %u",
+				sbi->root_reserved_blocks);
+	}
 	for (i = 0; i < NR_INODE_TYPE; i++) {
 		INIT_LIST_HEAD(&sbi->inode_list[i]);
 		spin_lock_init(&sbi->inode_lock[i]);
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 7e15cbc5b8e1..41887e6ec1b3 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -162,7 +162,8 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
 #endif
 	if (a->struct_type == RESERVED_BLOCKS) {
 		spin_lock(&sbi->stat_lock);
-		if (t > (unsigned long)sbi->user_block_count) {
+		if (t > (unsigned long)(sbi->user_block_count -
+					sbi->root_reserved_blocks)) {
 			spin_unlock(&sbi->stat_lock);
 			return -EINVAL;
 		}
-- 
2.15.0.531.g2ccb3012c9-goog

Re: [PATCH 2/2 v2] f2fs: add reserved blocks for root user

[Jaegeuk Kim]

This patch allows root to reserve some blocks via mount option.

"-o reserve_root=N" means N x 4KB-sized blocks for root only.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---

Change log from v1:
 - handle remount case to limit reserve_root=%u

 fs/f2fs/f2fs.h  | 20 ++++++++++++++++----
 fs/f2fs/super.c | 34 +++++++++++++++++++++++++++++++++-
 fs/f2fs/sysfs.c |  3 ++-
 3 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a52de99a34b9..4d255aac49bb 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -95,6 +95,7 @@ extern char *fault_name[FAULT_MAX];
 #define F2FS_MOUNT_PRJQUOTA		0x00200000
 #define F2FS_MOUNT_QUOTA		0x00400000
 #define F2FS_MOUNT_INLINE_XATTR_SIZE	0x00800000
+#define F2FS_MOUNT_RESERVE_ROOT		0x01000000
 
 #define clear_opt(sbi, option)	((sbi)->mount_opt.opt &= ~F2FS_MOUNT_##option)
 #define set_opt(sbi, option)	((sbi)->mount_opt.opt |= F2FS_MOUNT_##option)
@@ -1109,6 +1110,7 @@ struct f2fs_sb_info {
 	block_t last_valid_block_count;		/* for recovery */
 	block_t reserved_blocks;		/* configurable reserved blocks */
 	block_t current_reserved_blocks;	/* current reserved blocks */
+	block_t root_reserved_blocks;		/* root reserved blocks */
 
 	unsigned int nquota_files;		/* # of quota sysfile */
 
@@ -1590,11 +1592,17 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
 	sbi->total_valid_block_count += (block_t)(*count);
 	avail_user_block_count = sbi->user_block_count -
 					sbi->current_reserved_blocks;
+
+	if (!(test_opt(sbi, RESERVE_ROOT) && capable(CAP_SYS_RESOURCE)))
+		avail_user_block_count -= sbi->root_reserved_blocks;
+
 	if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {
 		diff = sbi->total_valid_block_count - avail_user_block_count;
+		if (diff > *count)
+			diff = *count;
 		*count -= diff;
 		release = diff;
-		sbi->total_valid_block_count = avail_user_block_count;
+		sbi->total_valid_block_count -= diff;
 		if (!*count) {
 			spin_unlock(&sbi->stat_lock);
 			percpu_counter_sub(&sbi->alloc_valid_block_count, diff);
@@ -1783,9 +1791,13 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi,
 
 	spin_lock(&sbi->stat_lock);
 
-	valid_block_count = sbi->total_valid_block_count + 1;
-	if (unlikely(valid_block_count + sbi->current_reserved_blocks >
-						sbi->user_block_count)) {
+	valid_block_count = sbi->total_valid_block_count +
+					sbi->current_reserved_blocks + 1;
+
+	if (!(test_opt(sbi, RESERVE_ROOT) && capable(CAP_SYS_RESOURCE)))
+		valid_block_count += sbi->root_reserved_blocks;
+
+	if (unlikely(valid_block_count > sbi->user_block_count)) {
 		spin_unlock(&sbi->stat_lock);
 		goto enospc;
 	}
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index f1300cda6bfd..f828a3ea3c9a 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -107,6 +107,7 @@ enum {
 	Opt_noextent_cache,
 	Opt_noinline_data,
 	Opt_data_flush,
+	Opt_reserve_root,
 	Opt_mode,
 	Opt_io_size_bits,
 	Opt_fault_injection,
@@ -157,6 +158,7 @@ static match_table_t f2fs_tokens = {
 	{Opt_noextent_cache, "noextent_cache"},
 	{Opt_noinline_data, "noinline_data"},
 	{Opt_data_flush, "data_flush"},
+	{Opt_reserve_root, "reserve_root=%u"},
 	{Opt_mode, "mode=%s"},
 	{Opt_io_size_bits, "io_bits=%u"},
 	{Opt_fault_injection, "fault_injection=%u"},
@@ -191,6 +193,19 @@ void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
 	va_end(args);
 }
 
+static inline void limit_reserve_root(struct f2fs_sb_info *sbi)
+{
+	block_t limit = (sbi->user_block_count << 1) / 1000;
+
+	/* limit is 0.2% */
+	if (test_opt(sbi, RESERVE_ROOT) && sbi->root_reserved_blocks > limit) {
+		sbi->root_reserved_blocks = limit;
+		f2fs_msg(sbi->sb, KERN_INFO,
+			"Reduce reserved blocks for root = %u",
+				sbi->root_reserved_blocks);
+	}
+}
+
 static void init_once(void *foo)
 {
 	struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
@@ -488,6 +503,18 @@ static int parse_options(struct super_block *sb, char *options)
 		case Opt_data_flush:
 			set_opt(sbi, DATA_FLUSH);
 			break;
+		case Opt_reserve_root:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+			if (test_opt(sbi, RESERVE_ROOT)) {
+				f2fs_msg(sb, KERN_INFO,
+					"Preserve previous reserve_root=%u",
+					sbi->root_reserved_blocks);
+			} else {
+				sbi->root_reserved_blocks = arg;
+				set_opt(sbi, RESERVE_ROOT);
+			}
+			break;
 		case Opt_mode:
 			name = match_strdup(&args[0]);
 
@@ -1006,7 +1033,7 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_blocks = total_count - start_count;
 	buf->f_bfree = user_block_count - valid_user_blocks(sbi) -
 						sbi->current_reserved_blocks;
-	buf->f_bavail = buf->f_bfree;
+	buf->f_bavail = buf->f_bfree - sbi->root_reserved_blocks;
 
 	avail_node_count = sbi->total_node_count - sbi->nquota_files -
 						F2FS_RESERVED_NODE_NUM;
@@ -1135,6 +1162,9 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 	else if (test_opt(sbi, LFS))
 		seq_puts(seq, "lfs");
 	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
+	if (test_opt(sbi, RESERVE_ROOT))
+		seq_printf(seq, ",reserve_root=%u",
+				sbi->root_reserved_blocks);
 	if (F2FS_IO_SIZE_BITS(sbi))
 		seq_printf(seq, ",io_size=%uKB", F2FS_IO_SIZE_KB(sbi));
 #ifdef CONFIG_F2FS_FAULT_INJECTION
@@ -1333,6 +1363,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 		(test_opt(sbi, POSIX_ACL) ? SB_POSIXACL : 0);
 
+	limit_reserve_root(sbi);
 	return 0;
 restore_gc:
 	if (need_restart_gc) {
@@ -2569,6 +2600,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	sbi->last_valid_block_count = sbi->total_valid_block_count;
 	sbi->reserved_blocks = 0;
 	sbi->current_reserved_blocks = 0;
+	limit_reserve_root(sbi);
 
 	for (i = 0; i < NR_INODE_TYPE; i++) {
 		INIT_LIST_HEAD(&sbi->inode_list[i]);
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 7e15cbc5b8e1..41887e6ec1b3 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -162,7 +162,8 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
 #endif
 	if (a->struct_type == RESERVED_BLOCKS) {
 		spin_lock(&sbi->stat_lock);
-		if (t > (unsigned long)sbi->user_block_count) {
+		if (t > (unsigned long)(sbi->user_block_count -
+					sbi->root_reserved_blocks)) {
 			spin_unlock(&sbi->stat_lock);
 			return -EINVAL;
 		}
-- 
2.15.0.531.g2ccb3012c9-goog

Re: [f2fs-dev] [PATCH 2/2 v2] f2fs: add reserved blocks for root user

[Chao Yu]

On 2018/1/4 14:51, Jaegeuk Kim wrote:
> This patch allows root to reserve some blocks via mount option.
> 
> "-o reserve_root=N" means N x 4KB-sized blocks for root only.
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,

Re: [PATCH 2/2 v3] f2fs: add reserved blocks for root user

[Jaegeuk Kim]

This patch allows root to reserve some blocks via mount option.

"-o reserve_root=N" means N x 4KB-sized blocks for root only.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---

Change log from v2:
 - fix overflow in statfs

 fs/f2fs/f2fs.h  | 20 ++++++++++++++++----
 fs/f2fs/super.c | 37 ++++++++++++++++++++++++++++++++++++-
 fs/f2fs/sysfs.c |  3 ++-
 3 files changed, 54 insertions(+), 6 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a52de99a34b9..4d255aac49bb 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -95,6 +95,7 @@ extern char *fault_name[FAULT_MAX];
 #define F2FS_MOUNT_PRJQUOTA		0x00200000
 #define F2FS_MOUNT_QUOTA		0x00400000
 #define F2FS_MOUNT_INLINE_XATTR_SIZE	0x00800000
+#define F2FS_MOUNT_RESERVE_ROOT		0x01000000
 
 #define clear_opt(sbi, option)	((sbi)->mount_opt.opt &= ~F2FS_MOUNT_##option)
 #define set_opt(sbi, option)	((sbi)->mount_opt.opt |= F2FS_MOUNT_##option)
@@ -1109,6 +1110,7 @@ struct f2fs_sb_info {
 	block_t last_valid_block_count;		/* for recovery */
 	block_t reserved_blocks;		/* configurable reserved blocks */
 	block_t current_reserved_blocks;	/* current reserved blocks */
+	block_t root_reserved_blocks;		/* root reserved blocks */
 
 	unsigned int nquota_files;		/* # of quota sysfile */
 
@@ -1590,11 +1592,17 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
 	sbi->total_valid_block_count += (block_t)(*count);
 	avail_user_block_count = sbi->user_block_count -
 					sbi->current_reserved_blocks;
+
+	if (!(test_opt(sbi, RESERVE_ROOT) && capable(CAP_SYS_RESOURCE)))
+		avail_user_block_count -= sbi->root_reserved_blocks;
+
 	if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {
 		diff = sbi->total_valid_block_count - avail_user_block_count;
+		if (diff > *count)
+			diff = *count;
 		*count -= diff;
 		release = diff;
-		sbi->total_valid_block_count = avail_user_block_count;
+		sbi->total_valid_block_count -= diff;
 		if (!*count) {
 			spin_unlock(&sbi->stat_lock);
 			percpu_counter_sub(&sbi->alloc_valid_block_count, diff);
@@ -1783,9 +1791,13 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi,
 
 	spin_lock(&sbi->stat_lock);
 
-	valid_block_count = sbi->total_valid_block_count + 1;
-	if (unlikely(valid_block_count + sbi->current_reserved_blocks >
-						sbi->user_block_count)) {
+	valid_block_count = sbi->total_valid_block_count +
+					sbi->current_reserved_blocks + 1;
+
+	if (!(test_opt(sbi, RESERVE_ROOT) && capable(CAP_SYS_RESOURCE)))
+		valid_block_count += sbi->root_reserved_blocks;
+
+	if (unlikely(valid_block_count > sbi->user_block_count)) {
 		spin_unlock(&sbi->stat_lock);
 		goto enospc;
 	}
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index f1300cda6bfd..4904d1644052 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -107,6 +107,7 @@ enum {
 	Opt_noextent_cache,
 	Opt_noinline_data,
 	Opt_data_flush,
+	Opt_reserve_root,
 	Opt_mode,
 	Opt_io_size_bits,
 	Opt_fault_injection,
@@ -157,6 +158,7 @@ static match_table_t f2fs_tokens = {
 	{Opt_noextent_cache, "noextent_cache"},
 	{Opt_noinline_data, "noinline_data"},
 	{Opt_data_flush, "data_flush"},
+	{Opt_reserve_root, "reserve_root=%u"},
 	{Opt_mode, "mode=%s"},
 	{Opt_io_size_bits, "io_bits=%u"},
 	{Opt_fault_injection, "fault_injection=%u"},
@@ -191,6 +193,19 @@ void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
 	va_end(args);
 }
 
+static inline void limit_reserve_root(struct f2fs_sb_info *sbi)
+{
+	block_t limit = (sbi->user_block_count << 1) / 1000;
+
+	/* limit is 0.2% */
+	if (test_opt(sbi, RESERVE_ROOT) && sbi->root_reserved_blocks > limit) {
+		sbi->root_reserved_blocks = limit;
+		f2fs_msg(sbi->sb, KERN_INFO,
+			"Reduce reserved blocks for root = %u",
+				sbi->root_reserved_blocks);
+	}
+}
+
 static void init_once(void *foo)
 {
 	struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
@@ -488,6 +503,18 @@ static int parse_options(struct super_block *sb, char *options)
 		case Opt_data_flush:
 			set_opt(sbi, DATA_FLUSH);
 			break;
+		case Opt_reserve_root:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+			if (test_opt(sbi, RESERVE_ROOT)) {
+				f2fs_msg(sb, KERN_INFO,
+					"Preserve previous reserve_root=%u",
+					sbi->root_reserved_blocks);
+			} else {
+				sbi->root_reserved_blocks = arg;
+				set_opt(sbi, RESERVE_ROOT);
+			}
+			break;
 		case Opt_mode:
 			name = match_strdup(&args[0]);
 
@@ -1006,7 +1033,10 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_blocks = total_count - start_count;
 	buf->f_bfree = user_block_count - valid_user_blocks(sbi) -
 						sbi->current_reserved_blocks;
-	buf->f_bavail = buf->f_bfree;
+	if (buf->f_bfree > sbi->root_reserved_blocks)
+		buf->f_bavail = buf->f_bfree - sbi->root_reserved_blocks;
+	else
+		buf->f_bavail = 0;
 
 	avail_node_count = sbi->total_node_count - sbi->nquota_files -
 						F2FS_RESERVED_NODE_NUM;
@@ -1135,6 +1165,9 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 	else if (test_opt(sbi, LFS))
 		seq_puts(seq, "lfs");
 	seq_printf(seq, ",active_logs=%u", sbi->active_logs);
+	if (test_opt(sbi, RESERVE_ROOT))
+		seq_printf(seq, ",reserve_root=%u",
+				sbi->root_reserved_blocks);
 	if (F2FS_IO_SIZE_BITS(sbi))
 		seq_printf(seq, ",io_size=%uKB", F2FS_IO_SIZE_KB(sbi));
 #ifdef CONFIG_F2FS_FAULT_INJECTION
@@ -1333,6 +1366,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 		(test_opt(sbi, POSIX_ACL) ? SB_POSIXACL : 0);
 
+	limit_reserve_root(sbi);
 	return 0;
 restore_gc:
 	if (need_restart_gc) {
@@ -2569,6 +2603,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	sbi->last_valid_block_count = sbi->total_valid_block_count;
 	sbi->reserved_blocks = 0;
 	sbi->current_reserved_blocks = 0;
+	limit_reserve_root(sbi);
 
 	for (i = 0; i < NR_INODE_TYPE; i++) {
 		INIT_LIST_HEAD(&sbi->inode_list[i]);
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 7e15cbc5b8e1..41887e6ec1b3 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -162,7 +162,8 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
 #endif
 	if (a->struct_type == RESERVED_BLOCKS) {
 		spin_lock(&sbi->stat_lock);
-		if (t > (unsigned long)sbi->user_block_count) {
+		if (t > (unsigned long)(sbi->user_block_count -
+					sbi->root_reserved_blocks)) {
 			spin_unlock(&sbi->stat_lock);
 			return -EINVAL;
 		}
-- 
2.15.0.531.g2ccb3012c9-goog

Re: [f2fs-dev] [PATCH 2/2] f2fs: add reserved blocks for root user

[Yunlong Song]

On 2018/1/4 2:58, Jaegeuk Kim wrote:
> @@ -1590,11 +1598,17 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
>   	sbi->total_valid_block_count += (block_t)(*count);
>   	avail_user_block_count = sbi->user_block_count -
>   					sbi->current_reserved_blocks;
> +
> +	if (!(test_opt(sbi, RESERVE_ROOT) && capable(CAP_SYS_RESOURCE)))
> +		avail_user_block_count -= sbi->root_reserved_blocks;

Should better be:

+	if (test_opt(sbi, RESERVE_ROOT) && !capable(CAP_SYS_RESOURCE))
+		avail_user_block_count -= sbi->root_reserved_blocks;

> @@ -1783,9 +1797,13 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi,
>   
>   	spin_lock(&sbi->stat_lock);
>   
> -	valid_block_count = sbi->total_valid_block_count + 1;
> -	if (unlikely(valid_block_count + sbi->current_reserved_blocks >
> -						sbi->user_block_count)) {
> +	valid_block_count = sbi->total_valid_block_count +
> +					sbi->current_reserved_blocks + 1;
> +

> +	if (!(test_opt(sbi, RESERVE_ROOT) && capable(CAP_SYS_RESOURCE)))
> +		valid_block_count += sbi->root_reserved_blocks;
> +
should better be:

+	if (test_opt(sbi, RESERVE_ROOT) && !capable(CAP_SYS_RESOURCE))
+		valid_block_count += sbi->root_reserved_blocks;


> +	if (unlikely(valid_block_count > sbi->user_block_count)) {
>   		spin_unlock(&sbi->stat_lock);
>   		goto enospc;
>   	}
>

-- 
Thanks,
Yunlong Song

Re: [f2fs-dev] [PATCH 1/2] f2fs: show precise # of blocks that user/root can use

[Chao Yu]

On 2018/1/4 2:58, Jaegeuk Kim wrote:
> Let's show precise # of blocks that user/root can use through bavail and bfree
> respectively.
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---
>  fs/f2fs/super.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 0a820ba55b10..4c1c99cf54ef 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -1005,9 +1005,9 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
>  	buf->f_bsize = sbi->blocksize;
>  
>  	buf->f_blocks = total_count - start_count;
> -	buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;

Clean up unused ovp_count in this patch?

Thanks,

> -	buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
> +	buf->f_bfree = user_block_count - valid_user_blocks(sbi) -
>  						sbi->current_reserved_blocks;
> +	buf->f_bavail = buf->f_bfree;
>  
>  	avail_node_count = sbi->total_node_count - sbi->nquota_files -
>  						F2FS_RESERVED_NODE_NUM;
> 

Re: [PATCH 1/2 v2] f2fs: show precise # of blocks that user/root can use

[Jaegeuk Kim]

Let's show precise # of blocks that user/root can use through bavail and bfree
respectively.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---

Change log from v1:
 - clean up obsolete values

 fs/f2fs/super.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 0a820ba55b10..f1300cda6bfd 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -994,20 +994,19 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	struct super_block *sb = dentry->d_sb;
 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
-	block_t total_count, user_block_count, start_count, ovp_count;
+	block_t total_count, user_block_count, start_count;
 	u64 avail_node_count;
 
 	total_count = le64_to_cpu(sbi->raw_super->block_count);
 	user_block_count = sbi->user_block_count;
 	start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
-	ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
 	buf->f_type = F2FS_SUPER_MAGIC;
 	buf->f_bsize = sbi->blocksize;
 
 	buf->f_blocks = total_count - start_count;
-	buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;
-	buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
+	buf->f_bfree = user_block_count - valid_user_blocks(sbi) -
 						sbi->current_reserved_blocks;
+	buf->f_bavail = buf->f_bfree;
 
 	avail_node_count = sbi->total_node_count - sbi->nquota_files -
 						F2FS_RESERVED_NODE_NUM;
-- 
2.15.0.531.g2ccb3012c9-goog

Re: [f2fs-dev] [PATCH 1/2 v2] f2fs: show precise # of blocks that user/root can use

[Chao Yu]

On 2018/1/4 14:50, Jaegeuk Kim wrote:
> Let's show precise # of blocks that user/root can use through bavail and bfree
> respectively.
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,

Re: [f2fs-dev] [PATCH 1/2] f2fs: show precise # of blocks that user/root can use

[Yunlong Song]

NACK

man statfs shows:

struct statfs {
     ...
     fsblkcnt_t   f_bfree;   /* free blocks in fs */
     fsblkcnt_t   f_bavail;  /* free blocks available to
                                     unprivileged user */
     ...
}

f_bfree is free blocks in fs, so buf->bfree should be

buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;

On 2018/1/4 2:58, Jaegeuk Kim wrote:
> Let's show precise # of blocks that user/root can use through bavail and bfree
> respectively.
>
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---
>   fs/f2fs/super.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 0a820ba55b10..4c1c99cf54ef 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -1005,9 +1005,9 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
>   	buf->f_bsize = sbi->blocksize;
>   
>   	buf->f_blocks = total_count - start_count;
> -	buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;
> -	buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
> +	buf->f_bfree = user_block_count - valid_user_blocks(sbi) -
>   						sbi->current_reserved_blocks;
> +	buf->f_bavail = buf->f_bfree;
>   
>   	avail_node_count = sbi->total_node_count - sbi->nquota_files -
>   						F2FS_RESERVED_NODE_NUM;

-- 
Thanks,
Yunlong Song

Re: [f2fs-dev] [PATCH 1/2] f2fs: show precise # of blocks that user/root can use

[Chao Yu]

On 2018/1/5 15:05, Yunlong Song wrote:
> NACK
> 
> man statfs shows:
> 
> struct statfs {
>      ...
>      fsblkcnt_t   f_bfree;   /* free blocks in fs */
>      fsblkcnt_t   f_bavail;  /* free blocks available to
>                                      unprivileged user */
>      ...
> }
> 
> f_bfree is free blocks in fs, so buf->bfree should be
> 
> buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;

As I checked, some filesystems reserving over-privision space like
btrfs/xfs/ubifs, they will not calculate those space into f_bfree, IMO, we
should follow their behavior to keep compatibility for old applications.

Thanks,

> 
> On 2018/1/4 2:58, Jaegeuk Kim wrote:
>> Let's show precise # of blocks that user/root can use through bavail and bfree
>> respectively.
>>
>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
>> ---
>>   fs/f2fs/super.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>> index 0a820ba55b10..4c1c99cf54ef 100644
>> --- a/fs/f2fs/super.c
>> +++ b/fs/f2fs/super.c
>> @@ -1005,9 +1005,9 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
>>   	buf->f_bsize = sbi->blocksize;
>>   
>>   	buf->f_blocks = total_count - start_count;
>> -	buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;
>> -	buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
>> +	buf->f_bfree = user_block_count - valid_user_blocks(sbi) -
>>   						sbi->current_reserved_blocks;
>> +	buf->f_bavail = buf->f_bfree;
>>   
>>   	avail_node_count = sbi->total_node_count - sbi->nquota_files -
>>   						F2FS_RESERVED_NODE_NUM;
>