This is a note to let you know that I've just added the patch titled ext4: convert BUG_ON's to WARN_ON's in mballoc.c to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ext4-convert-bug_on-s-to-warn_on-s-in-mballoc.c.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 55382d41c1c4d401934192310000fc86249c8149 Author: Theodore Ts'o <tytso@xxxxxxx> Date: Mon Apr 13 23:33:05 2020 -0400 ext4: convert BUG_ON's to WARN_ON's in mballoc.c [ Upstream commit 907ea529fc4c3296701d2bfc8b831dd2a8121a34 ] If the in-core buddy bitmap gets corrupted (or out of sync with the block bitmap), issue a WARN_ON and try to recover. In most cases this involves skipping trying to allocate out of a particular block group. We can end up declaring the file system corrupted, which is fair, since the file system probably should be checked before we proceed any further. Link: https://lore.kernel.org/r/20200414035649.293164-1-tytso@xxxxxxx Google-Bug-Id: 34811296 Google-Bug-Id: 34639169 Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index c76ffc259d197..e1782b2e2e2dd 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1936,7 +1936,8 @@ void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac, int free; free = e4b->bd_info->bb_free; - BUG_ON(free <= 0); + if (WARN_ON(free <= 0)) + return; i = e4b->bd_info->bb_first_free; @@ -1959,7 +1960,8 @@ void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac, } mb_find_extent(e4b, i, ac->ac_g_ex.fe_len, &ex); - BUG_ON(ex.fe_len <= 0); + if (WARN_ON(ex.fe_len <= 0)) + break; if (free < ex.fe_len) { ext4_grp_locked_error(sb, e4b->bd_group, 0, 0, "%d free clusters as per "