From: Theodore Ts'o <tytso@xxxxxxx> [ 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> --- fs/ext4/mballoc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index c18668e3135e8..ac13de1a7e420 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1944,7 +1944,8 @@ 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; @@ -1965,7 +1966,8 @@ 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 " -- 2.20.1
