[PATCH 5.4 031/434] btrfs: return error pointer from alloc_test_extent_buffer

From: Greg Kroah-Hartman
Date: Sun Dec 29 2019 - 12:46:19 EST


From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit b6293c821ea8fa2a631a2112cd86cd435effeb8b upstream.

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@xxxxxxxxxxxxxxx # 4.4+
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/btrfs/extent_io.c | 6 ++++--
fs/btrfs/tests/free-space-tree-tests.c | 4 ++--
fs/btrfs/tests/qgroup-tests.c | 4 ++--
3 files changed, 8 insertions(+), 6 deletions(-)

--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -5066,12 +5066,14 @@ struct extent_buffer *alloc_test_extent_
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);
--- a/fs/btrfs/tests/free-space-tree-tests.c
+++ b/fs/btrfs/tests/free-space-tree-tests.c
@@ -463,9 +463,9 @@ static int run_test(test_func_t test_fun
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_std_err(TEST_ALLOC_EXTENT_BUFFER);
- ret = -ENOMEM;
+ ret = PTR_ERR(root->node);
goto out;
}
btrfs_set_header_level(root->node, 0);
--- a/fs/btrfs/tests/qgroup-tests.c
+++ b/fs/btrfs/tests/qgroup-tests.c
@@ -484,9 +484,9 @@ int btrfs_test_qgroups(u32 sectorsize, u
* *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);