[PATCH 6.13] btrfs: ioctl: error on fixed buffer flag for io-uring cmd

[PATCH 6.13] btrfs: ioctl: error on fixed buffer flag for io-uring cmd

[Sidong Yang]

Currently, the io-uring fixed buffer cmd flag is silently dismissed,
even though it does not work. This patch returns an error when the flag
is set, making it clear that operation is not supported.

Fixes: 34310c442e17 ("btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)")
Cc: stable@vger.kernel.org
Signed-off-by: Sidong Yang <sidong.yang@furiosa.ai>
---
 fs/btrfs/ioctl.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4d9305fa37a8..98d99f2f7926 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4906,6 +4906,12 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue
 		ret = -EPERM;
 		goto out_acct;
 	}
+
+	if (cmd->flags & IORING_URING_CMD_FIXED) {
+		ret = -EOPNOTSUPP;
+		goto out_acct;
+	}
+
 	file = cmd->file;
 	inode = BTRFS_I(file->f_inode);
 	fs_info = inode->root->fs_info;
-- 
2.43.0

Re: [PATCH 6.13] btrfs: ioctl: error on fixed buffer flag for io-uring cmd

[kernel test robot]

Hi,

Thanks for your patch.

FYI: kernel test robot notices the stable kernel rule is not satisfied.

The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-3

Rule: The upstream commit ID must be specified with a separate line above the commit text.
Subject: [PATCH 6.13] btrfs: ioctl: error on fixed buffer flag for io-uring cmd
Link: https://lore.kernel.org/stable/20250326160351.612359-1-sidong.yang%40furiosa.ai

Please ignore this mail if the patch is not relevant for upstream.

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 6.13] btrfs: ioctl: error on fixed buffer flag for io-uring cmd

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
⚠️ Could not find matching upstream commit

No upstream commit was identified. Using temporary commit for testing.

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.13.y       |  Success    |  Success   |