| Message ID | 1366636451-2151-1-git-send-email-jbacik@fusionio.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Apr 22, 2013 at 09:14:11AM -0400, Josef Bacik wrote: > 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, There are various call paths that lead to __btrfs_map_block, via btrfs_map_block (and btrfs_map_bio). Lots of the retval checks are still marked with /* ENOMEM */ so it does not seem that all the paths were verified to be safe wrt EIO. After a quick skim I think that most of the callsites are doing proper error handling (and some of them continue to BUG_ON(ret < 0)) namely after the btrfs_map_bio handling that Stefan did. Remains to make sure that btrfs_map_block are also ok, sofar I don't see major problems right now. As you're extending the set of return values please remove all the ENOMEM comments like btrfs_map_bio(): 5278 ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio, 5279 mirror_num, &raid_map); 5280 if (ret) /* -ENOMEM */ so comments and code match. david -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 76ded9e..c8a315d 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -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;
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: Martin Steigerwald <Martin@lichtvoll.de> Signed-off-by: Josef Bacik <jbacik@fusionio.com> --- fs/btrfs/volumes.c | 10 ++++++++-- 1 files changed, 8 insertions(+), 2 deletions(-)