From 8d03c7a0c550e7ab24cadcef5e66656bfadec8b9 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Sat, 14 Mar 2009 11:51:46 -0400 Subject: [PATCH] ext4: fix bogus BUG_ONs in in mballoc code Thiemo Nagel reported that: # dd if=/dev/zero of=image.ext4 bs=1M count=2 # mkfs.ext4 -v -F -b 1024 -m 0 -g 512 -G 4 -I 128 -N 1 \ -O large_file,dir_index,flex_bg,extent,sparse_super image.ext4 # mount -o loop image.ext4 mnt/ # dd if=/dev/zero of=mnt/file oopsed, with a BUG_ON in ext4_mb_normalize_request because size == EXT4_BLOCKS_PER_GROUP It appears to me (esp. after talking to Andreas) that the BUG_ON is bogus; a request of exactly EXT4_BLOCKS_PER_GROUP should be allowed, though larger sizes do indicate a problem. Fix that an another (apparently rare) codepath with a similar check. Reported-by: Thiemo Nagel Signed-off-by: Eric Sandeen Signed-off-by: "Theodore Ts'o" --- fs/ext4/mballoc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 4415beeb0b62..41f4348b62f5 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1447,7 +1447,7 @@ static void ext4_mb_measure_extent(struct ext4_allocation_context *ac, struct ext4_free_extent *gex = &ac->ac_g_ex; BUG_ON(ex->fe_len <= 0); - BUG_ON(ex->fe_len >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); + BUG_ON(ex->fe_len > EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); BUG_ON(ex->fe_start >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); BUG_ON(ac->ac_status != AC_STATUS_CONTINUE); @@ -3292,7 +3292,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac, } BUG_ON(start + size <= ac->ac_o_ex.fe_logical && start > ac->ac_o_ex.fe_logical); - BUG_ON(size <= 0 || size >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); + BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); /* now prepare goal request */ -- GitLab