f2fs: support soft block reservation
It supports to extend reserved_blocks sysfs interface to be soft
threshold, which allows user configure it exceeding current available
user space. This patch also introduces a new sysfs interface called
current_reserved_blocks, which shows the current blocks that have
already been reserved.
Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 13a96b8..5ed40fb 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1082,6 +1082,7 @@ struct f2fs_sb_info {
block_t discard_blks; /* discard command candidats */
block_t last_valid_block_count; /* for recovery */
block_t reserved_blocks; /* configurable reserved blocks */
+ block_t current_reserved_blocks; /* current reserved blocks */
u32 s_next_generation; /* for NFS support */
@@ -1557,7 +1558,8 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
spin_lock(&sbi->stat_lock);
sbi->total_valid_block_count += (block_t)(*count);
- avail_user_block_count = sbi->user_block_count - sbi->reserved_blocks;
+ avail_user_block_count = sbi->user_block_count -
+ sbi->current_reserved_blocks;
if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {
diff = sbi->total_valid_block_count - avail_user_block_count;
*count -= diff;
@@ -1591,6 +1593,10 @@ static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
f2fs_bug_on(sbi, sbi->total_valid_block_count < (block_t) count);
f2fs_bug_on(sbi, inode->i_blocks < sectors);
sbi->total_valid_block_count -= (block_t)count;
+ if (sbi->reserved_blocks &&
+ sbi->current_reserved_blocks < sbi->reserved_blocks)
+ sbi->current_reserved_blocks = min(sbi->reserved_blocks,
+ sbi->current_reserved_blocks + count);
spin_unlock(&sbi->stat_lock);
f2fs_i_blocks_write(inode, count, false, true);
}
@@ -1737,7 +1743,7 @@ 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->reserved_blocks >
+ if (unlikely(valid_block_count + sbi->current_reserved_blocks >
sbi->user_block_count)) {
spin_unlock(&sbi->stat_lock);
goto enospc;
@@ -1780,6 +1786,9 @@ static inline void dec_valid_node_count(struct f2fs_sb_info *sbi,
sbi->total_valid_node_count--;
sbi->total_valid_block_count--;
+ if (sbi->reserved_blocks &&
+ sbi->current_reserved_blocks < sbi->reserved_blocks)
+ sbi->current_reserved_blocks++;
spin_unlock(&sbi->stat_lock);