btrfs: return error pointer from alloc_test_extent_buffer

[ Upstream commit b6293c821ea8fa2a631a2112cd86cd435effeb8b ]

Callers of alloc_test_extent_buffer have not correctly interpreted the
return value as error pointer, as alloc_test_extent_buffer should behave
as alloc_extent_buffer. The self-tests were unaffected but
btrfs_find_create_tree_block could call both functions and that would
cause problems up in the call chain.

Fixes: faa2dbf004e8 ("Btrfs: add sanity tests for new qgroup accounting code")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 88fc5a0..fed4439 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4888,12 +4888,14 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
                return eb;
        eb = alloc_dummy_extent_buffer(fs_info, start);
        if (!eb)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
        eb->fs_info = fs_info;
 again:
        ret = radix_tree_preload(GFP_NOFS);
-       if (ret)
+       if (ret) {
+               exists = ERR_PTR(ret);
                goto free_eb;
+       }
        spin_lock(&fs_info->buffer_lock);
        ret = radix_tree_insert(&fs_info->buffer_radix,
                                start >> PAGE_SHIFT, eb);

diff --git a/fs/btrfs/tests/free-space-tree-tests.c b/fs/btrfs/tests/free-space-tree-tests.c
index 89346da..de8fef9 100644 (file)
--- a/fs/btrfs/tests/free-space-tree-tests.c
+++ b/fs/btrfs/tests/free-space-tree-tests.c
@@ -462,9 +462,9 @@ static int run_test(test_func_t test_func, int bitmaps, u32 sectorsize,
        root->fs_info->tree_root = root;
 
        root->node = alloc_test_extent_buffer(root->fs_info, nodesize);
-       if (!root->node) {
+       if (IS_ERR(root->node)) {
                test_err("couldn't allocate dummy buffer");
-               ret = -ENOMEM;
+               ret = PTR_ERR(root->node);
                goto out;
        }
        btrfs_set_header_level(root->node, 0);

diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c
index 412b910..d07dd26 100644 (file)
--- a/fs/btrfs/tests/qgroup-tests.c
+++ b/fs/btrfs/tests/qgroup-tests.c
@@ -484,9 +484,9 @@ int btrfs_test_qgroups(u32 sectorsize, u32 nodesize)
         * *cough*backref walking code*cough*
         */
        root->node = alloc_test_extent_buffer(root->fs_info, nodesize);
-       if (!root->node) {
+       if (IS_ERR(root->node)) {
                test_err("couldn't allocate dummy buffer");
-               ret = -ENOMEM;
+               ret = PTR_ERR(root->node);
                goto out;
        }
        btrfs_set_header_level(root->node, 0);