Josef Bacik
2010-Mar-19 20:49 UTC
[PATCH] 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. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
---
fs/btrfs/disk-io.c | 11 ++++++++---
fs/btrfs/extent-tree.c | 5 ++++-
2 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index dfe7a95..6632e5c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1921,7 +1921,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
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;
@@ -1931,7 +1935,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
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,
@@ -2019,7 +2023,8 @@ fail_cleaner:
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 1860969..ec84862 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4179,6 +4179,10 @@ 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;
@@ -7378,7 +7382,6 @@ static int find_first_block_group(struct btrfs_root *root,
}
path->slots[0]++;
}
- ret = -ENOENT;
out:
return ret;
}
--
1.6.6
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