Btrfs: fail to mount if we have problems reading the block groups

We don't actually check the return value of btrfs_read_block_groups, so we can
possibly succeed to mount, but then fail to say read the superblock xattr for
selinux which will cause the vfs code to deactivate the super.

This is a problem because in find_free_extent we just assume that we
will find the right space_info for the allocation we want.  But if we
failed to read the block groups, we won't have setup any space_info's,
and we'll hit a NULL pointer deref in find_free_extent.

This patch fixes that problem by checking the return value of
btrfs_read_block_groups, and failing out properly.  I've also added a
check in find_free_extent so if for some reason we don't find an
appropriate space_info, we just return -ENOSPC.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Josef Bacik
2010-03-19 20:49:55 +00:00
committed by Chris Mason
parent 6cf8bfbf5e
commit 1b1d1f6625
2 changed files with 12 additions and 4 deletions

View File

@ -4170,6 +4170,10 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans,
ins->offset = 0;
space_info = __find_space_info(root->fs_info, data);
if (!space_info) {
printk(KERN_ERR "No space info for %d\n", data);
return -ENOSPC;
}
if (orig_root->ref_cows || empty_size)
allowed_chunk_alloc = 1;
@ -7372,7 +7376,6 @@ static int find_first_block_group(struct btrfs_root *root,
}
path->slots[0]++;
}
ret = -ENOENT;
out:
return ret;
}