From fbf48bb0b197e6894a04c714728c952af7153bf3 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@suse.com>
Date: Wed, 3 Mar 2021 18:41:51 +0800
Patch-mainline: v5.12-rc4
Git-commit: fbf48bb0b197e6894a04c714728c952af7153bf3
References: bsc#1185549
Subject: [PATCH 1/2] btrfs: track qgroup released data in own variable in
insert_prealloc_file_extent
There is a piece of weird code in insert_prealloc_file_extent(), which
looks like:
ret = btrfs_qgroup_release_data(inode, file_offset, len);
if (ret < 0)
return ERR_PTR(ret);
if (trans) {
ret = insert_reserved_file_extent(trans, inode,
file_offset, &stack_fi,
true, ret);
...
}
extent_info.is_new_extent = true;
extent_info.qgroup_reserved = ret;
...
Note how the variable @ret is abused here, and if anyone is adding code
just after btrfs_qgroup_release_data() call, it's super easy to
overwrite the @ret and cause tons of qgroup related bugs.
Fix such abuse by introducing new variable @qgroup_released, so that we
won't reuse the existing variable @ret.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
fs/btrfs/inode.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10476,6 +10476,7 @@ static struct btrfs_trans_handle *insert
struct btrfs_path *path;
u64 start = ins->objectid;
u64 len = ins->offset;
+ int qgroup_released;
int ret;
memset(&stack_fi, 0, sizeof(stack_fi));
@@ -10488,13 +10489,14 @@ static struct btrfs_trans_handle *insert
btrfs_set_stack_file_extent_compression(&stack_fi, BTRFS_COMPRESS_NONE);
/* Encryption and other encoding is reserved and all 0 */
- ret = btrfs_qgroup_release_data(inode, file_offset, len);
- if (ret < 0)
- return ERR_PTR(ret);
+ qgroup_released = btrfs_qgroup_release_data(inode, file_offset, len);
+ if (qgroup_released < 0)
+ return ERR_PTR(qgroup_released);
if (trans) {
ret = insert_reserved_file_extent(trans, inode,
- file_offset, &stack_fi, ret);
+ file_offset, &stack_fi,
+ qgroup_released);
if (ret)
return ERR_PTR(ret);
return trans;
@@ -10507,7 +10509,7 @@ static struct btrfs_trans_handle *insert
extent_info.file_offset = file_offset;
extent_info.extent_buf = (char *)&stack_fi;
extent_info.is_new_extent = true;
- extent_info.qgroup_reserved = ret;
+ extent_info.qgroup_reserved = qgroup_released;
extent_info.insertions = 0;
path = btrfs_alloc_path();