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Commit 9bb91873 authored by Josef Bacik's avatar Josef Bacik
Browse files

Btrfs: deal with bad mappings in btrfs_map_block 



Martin Steigerwald reported a BUG_ON() in btrfs_map_block where we didn't find
a chunk for a particular block we were trying to map.  This happened because the
block was bogus.  We shouldn't be BUG_ON()'ing in this case, just print a
message and return an error.  This came from reada_add_block and it appears to
deal with an error fine so we should be good there.  Thanks,

Reported-by: default avatarMartin Steigerwald <Martin@lichtvoll.de>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
parent d4c7ca86

fs/btrfs/volumes.c

+8 −2
Original line number Diff line number Diff line
@@ -4406,10 +4406,16 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, 
		btrfs_crit(fs_info, "unable to find logical %llu len %llu",

			(unsigned long long)logical,

			(unsigned long long)*length);

		BUG();

		return -EINVAL;

	}



	if (em->start > logical || em->start + em->len < logical) {

		btrfs_crit(fs_info, "found a bad mapping, wanted %Lu, "

			   "found %Lu-%Lu\n", logical, em->start,

			   em->start + em->len);

		return -EINVAL;

	}



	BUG_ON(em->start > logical || em->start + em->len < logical);

	map = (struct map_lookup *)em->bdev;

	offset = logical - em->start;