[PATCH v2] f2fs: avoid setting SBI_NEED_FSCK on transient resize failure

[Daeho Jeong <daeho43@gmail.com>]

From: Daeho Jeong <daehojeong@google.com>

When free_segment_range() fails in f2fs_resize_fs(), no on-disk
superblock or filesystem metadata has been modified yet, and
free_segment_range() safely restores all in-memory counters before
returning.

However, the current error recovery path unconditionally sets the
SBI_NEED_FSCK flag and prints a scary error message on any error,
forcing an unnecessary and time-consuming fsck.f2fs repair on the
subsequent mount/reboot.

Fix this by separating the error recovery path with a dedicated
recover_user_blocks label to bypass setting SBI_NEED_FSCK on
free_segment_range() failures.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Sunmin Jeong <s_min.jeong@samsung.com>
---
v2: separate error recovery path to bypass SBI_NEED_FSCK on
    free_segment_range() failure and add f2fs_bug_on() in recover_out.
---
 fs/f2fs/gc.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index c4da2f31805b..3215630c353d 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -2440,7 +2440,7 @@ int f2fs_resize_fs(struct file *filp, __u64 block_count)
 	set_sbi_flag(sbi, SBI_IS_RESIZEFS);
 	err = free_segment_range(sbi, secs, false);
 	if (err)
-		goto recover_out;
+		goto recover_user_blocks;
 
 	update_sb_metadata(sbi, -secs);
 
@@ -2462,11 +2462,14 @@ int f2fs_resize_fs(struct file *filp, __u64 block_count)
 		f2fs_commit_super(sbi, false);
 	}
 recover_out:
-	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
 	if (err) {
+		f2fs_bug_on(sbi, err == -EAGAIN);
 		set_sbi_flag(sbi, SBI_NEED_FSCK);
 		f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
-
+	}
+recover_user_blocks:
+	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
+	if (err) {
 		spin_lock(&sbi->stat_lock);
 		sbi->user_block_count += shrunk_blocks;
 		spin_unlock(&sbi->stat_lock);
-- 
2.55.0.737.g08866a6d13-goog