From: Theodore Ts'o tytso@mit.edu
[ 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@mit.edu Google-Bug-Id: 34811296 Google-Bug-Id: 34639169 Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Sasha Levin sashal@kernel.org --- 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 71121fcf9e8cc..8dd54a8a03610 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 "