[PATCH AUTOSEL 5.15 02/11] btrfs: raid56: properly handle the error when unable to find the missing stripe

[PATCH AUTOSEL 5.15 02/11] btrfs: raid56: properly handle the error when unable to find the missing stripe

[Sasha Levin]

From: Qu Wenruo <wqu@suse.com>

[ Upstream commit f15fb2cd979a07fbfc666e2f04b8b30ec9233b2a ]

In raid56_alloc_missing_rbio(), if we can not determine where the
missing device is inside the full stripe, we just BUG_ON().

This is not necessary especially the only caller inside scrub.c is
already properly checking the return value, and will treat it as a
memory allocation failure.

Fix the error handling by:

- Add an extra warning for the reason
  Although personally speaking it may be better to be an ASSERT().

- Properly free the allocated rbio

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/raid56.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 3157a26ddf7e..5b27c289139a 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -2728,8 +2728,10 @@ raid56_alloc_missing_rbio(struct btrfs_fs_info *fs_info, struct bio *bio,
 
 	rbio->faila = find_logical_bio_stripe(rbio, bio);
 	if (rbio->faila == -1) {
-		BUG();
-		kfree(rbio);
+		btrfs_warn_rl(fs_info,
+	"can not determine the failed stripe number for full stripe %llu",
+			      bioc->raid_map[0]);
+		__free_raid_bio(rbio);
 		return NULL;
 	}
 
-- 
2.35.1

[PATCH AUTOSEL 5.15 09/11] btrfs: remove pointless and double ulist frees in error paths of qgroup tests

[Sasha Levin]

From: Filipe Manana <fdmanana@suse.com>

[ Upstream commit d0ea17aec12ea0f7b9d2ed727d8ef8169d1e7699 ]

Several places in the qgroup self tests follow the pattern of freeing the
ulist pointer they passed to btrfs_find_all_roots() if the call to that
function returned an error. That is pointless because that function always
frees the ulist in case it returns an error.

Also In some places like at test_multiple_refs(), after a call to
btrfs_qgroup_account_extent() we also leave "old_roots" and "new_roots"
pointing to ulists that were freed, because btrfs_qgroup_account_extent()
has freed those ulists, and if after that the next call to
btrfs_find_all_roots() fails, we call ulist_free() on the "old_roots"
ulist again, resulting in a double free.

So remove those calls to reduce the code size and avoid double ulist
free in case of an error.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/tests/qgroup-tests.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c
index 19ba7d5b7d8f..a8c6637fe337 100644
--- a/fs/btrfs/tests/qgroup-tests.c
+++ b/fs/btrfs/tests/qgroup-tests.c
@@ -225,7 +225,6 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 	 */
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots, false);
 	if (ret) {
-		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
 		return ret;
 	}
@@ -238,7 +237,6 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
-		ulist_free(new_roots);
 		test_err("couldn't find old roots: %d", ret);
 		return ret;
 	}
@@ -250,17 +248,18 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 		return ret;
 	}
 
+	/* btrfs_qgroup_account_extent() always frees the ulists passed to it. */
+	old_roots = NULL;
+	new_roots = NULL;
+
 	if (btrfs_verify_qgroup_counts(fs_info, BTRFS_FS_TREE_OBJECTID,
 				nodesize, nodesize)) {
 		test_err("qgroup counts didn't match expected values");
 		return -EINVAL;
 	}
-	old_roots = NULL;
-	new_roots = NULL;
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots, false);
 	if (ret) {
-		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
 		return ret;
 	}
@@ -272,7 +271,6 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
-		ulist_free(new_roots);
 		test_err("couldn't find old roots: %d", ret);
 		return ret;
 	}
@@ -322,7 +320,6 @@ static int test_multiple_refs(struct btrfs_root *root,
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots, false);
 	if (ret) {
-		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
 		return ret;
 	}
@@ -335,7 +332,6 @@ static int test_multiple_refs(struct btrfs_root *root,
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
-		ulist_free(new_roots);
 		test_err("couldn't find old roots: %d", ret);
 		return ret;
 	}
@@ -355,7 +351,6 @@ static int test_multiple_refs(struct btrfs_root *root,
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots, false);
 	if (ret) {
-		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
 		return ret;
 	}
@@ -368,7 +363,6 @@ static int test_multiple_refs(struct btrfs_root *root,
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
-		ulist_free(new_roots);
 		test_err("couldn't find old roots: %d", ret);
 		return ret;
 	}
@@ -394,7 +388,6 @@ static int test_multiple_refs(struct btrfs_root *root,
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots, false);
 	if (ret) {
-		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
 		return ret;
 	}
@@ -407,7 +400,6 @@ static int test_multiple_refs(struct btrfs_root *root,
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots, false);
 	if (ret) {
 		ulist_free(old_roots);
-		ulist_free(new_roots);
 		test_err("couldn't find old roots: %d", ret);
 		return ret;
 	}
-- 
2.35.1