Commit 1b1d1f66 authored by Josef Bacik's avatar Josef Bacik Committed by Chris Mason
Browse files

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: default avatarJosef Bacik <>
Signed-off-by: default avatarChris Mason <>
parent 6cf8bfbf
......@@ -1922,7 +1922,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
csum_root->track_dirty = 1;
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 @@ struct btrfs_root *open_ctree(struct super_block *sb,
fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
if (IS_ERR(fs_info->cleaner_kthread))
goto fail_csum_root;
goto fail_block_groups;
fs_info->transaction_kthread = kthread_run(transaction_kthread,
......@@ -2020,7 +2024,8 @@ fail_cleaner:
......@@ -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,
ret = -ENOENT;
return ret;
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