f2fs: introduce reserved_blocks in sysfs
In this patch, we add a new sysfs interface, with it, we can control
number of reserved blocks in system which could not be used by user,
it enable f2fs to let user to configure for adjusting over-provision
ratio dynamically instead of changing it by mkfs.
So we can expect it will help to reserve more free space for relieving
GC in both filesystem and flash device.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 3da6fb2..c45bac6 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -691,7 +691,8 @@ 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) + ovp_count;
- buf->f_bavail = user_block_count - valid_user_blocks(sbi);
+ buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
+ sbi->reserved_blocks;
avail_node_count = sbi->total_node_count - F2FS_RESERVED_NODE_NUM;
@@ -1768,6 +1769,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
sbi->total_valid_block_count =
le64_to_cpu(sbi->ckpt->valid_block_count);
sbi->last_valid_block_count = sbi->total_valid_block_count;
+ sbi->reserved_blocks = 0;
for (i = 0; i < NR_INODE_TYPE; i++) {
INIT_LIST_HEAD(&sbi->inode_list[i]);