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>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 11d0ad3..5ae1c0f 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1922,7 +1922,11 @@
csum_root->track_dirty = 1;
- btrfs_read_block_groups(extent_root);
+ ret = btrfs_read_block_groups(extent_root);
+ if (ret) {
+ printk(KERN_ERR "Failed to read block groups: %d\n", ret);
+ goto fail_block_groups;
+ }
fs_info->generation = generation;
fs_info->last_trans_committed = generation;
@@ -1932,7 +1936,7 @@
fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
"btrfs-cleaner");
if (IS_ERR(fs_info->cleaner_kthread))
- goto fail_csum_root;
+ goto fail_block_groups;
fs_info->transaction_kthread = kthread_run(transaction_kthread,
tree_root,
@@ -2020,7 +2024,8 @@
filemap_write_and_wait(fs_info->btree_inode->i_mapping);
invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
-fail_csum_root:
+fail_block_groups:
+ btrfs_free_block_groups(fs_info);
free_extent_buffer(csum_root->node);
free_extent_buffer(csum_root->commit_root);
fail_dev_root:
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 503a18e..4c91035 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4170,6 +4170,10 @@
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 @@
}
path->slots[0]++;
}
- ret = -ENOENT;
out:
return ret;
}