[PATCH v2] io_uring: Change res2 parameter type in io_uring_cmd_done

[PATCH v2] io_uring: Change res2 parameter type in io_uring_cmd_done

[Bernd Schubert]

Change the type of the res2 parameter in io_uring_cmd_done from ssize_t
to u64. This aligns the parameter type with io_req_set_cqe32_extra,
which expects u64 arguments.
The change eliminates potential issues on 32-bit architectures where
ssize_t might be 32-bit.

Only user of passing res2 is drivers/nvme/host/ioctl.c and it actually
passes u64.

Fixes: ee692a21e9bf ("fs,io_uring: add infrastructure for uring-cmd")
Cc: stable@vger.kernel.org
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Tested-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Li Zetao <lizetao1@huawei.com>
Signed-off-by: Bernd Schubert <bschubert@ddn.com>
---
Changes in v2:
- As suggested by Li Zetao, also update the type with CONFIG_IO_URING=n
- Link to v1: https://lore.kernel.org/r/20241202-io_uring_cmd_done-res2-as-u64-v1-1-74f33388c3d8@ddn.com
---
 include/linux/io_uring/cmd.h | 4 ++--
 io_uring/uring_cmd.c         | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h
index 578a3fdf5c719cf45fd4b6f9c894204d6b4f946c..0d5448c0b86cdde2e9764842adebafa1f8f49e61 100644
--- a/include/linux/io_uring/cmd.h
+++ b/include/linux/io_uring/cmd.h
@@ -43,7 +43,7 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
  * Note: the caller should never hard code @issue_flags and is only allowed
  * to pass the mask provided by the core io_uring code.
  */
-void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, ssize_t res2,
+void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, u64 res2,
 			unsigned issue_flags);
 
 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
@@ -67,7 +67,7 @@ static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 	return -EOPNOTSUPP;
 }
 static inline void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret,
-		ssize_t ret2, unsigned issue_flags)
+		u64 ret2, unsigned issue_flags)
 {
 }
 static inline void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index d9fb2143f56ff5d13483687fa949c293f9b8dbef..af842e9b4eb975ba56aaeaaa0c2e207a7732beba 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -151,7 +151,7 @@ static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
  * Called by consumers of io_uring_cmd, if they originally returned
  * -EIOCBQUEUED upon receiving the command.
  */
-void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2,
+void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, u64 res2,
 		       unsigned issue_flags)
 {
 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);

---
base-commit: 7af08b57bcb9ebf78675c50069c54125c0a8b795
change-id: 20241202-io_uring_cmd_done-res2-as-u64-217a4e47b93f

Best regards,
-- 
Bernd Schubert <bschubert@ddn.com>

Re: [PATCH v2] io_uring: Change res2 parameter type in io_uring_cmd_done

[Pavel Begunkov]

On 12/3/24 10:31, Bernd Schubert wrote:
> Change the type of the res2 parameter in io_uring_cmd_done from ssize_t
> to u64. This aligns the parameter type with io_req_set_cqe32_extra,
> which expects u64 arguments.
> The change eliminates potential issues on 32-bit architectures where
> ssize_t might be 32-bit.
> 
> Only user of passing res2 is drivers/nvme/host/ioctl.c and it actually
> passes u64.

LGTM. We can also convert all parameters to match the ABI, i.e.
io_uring_cqe::res is s32, "ssize_t ret" is just truncated.

-- 
Pavel Begunkov

Re: [PATCH v2] io_uring: Change res2 parameter type in io_uring_cmd_done

[Jens Axboe]

On Tue, 03 Dec 2024 11:31:05 +0100, Bernd Schubert wrote:
> Change the type of the res2 parameter in io_uring_cmd_done from ssize_t
> to u64. This aligns the parameter type with io_req_set_cqe32_extra,
> which expects u64 arguments.
> The change eliminates potential issues on 32-bit architectures where
> ssize_t might be 32-bit.
> 
> Only user of passing res2 is drivers/nvme/host/ioctl.c and it actually
> passes u64.
> 
> [...]

Applied, thanks!

[1/1] io_uring: Change res2 parameter type in io_uring_cmd_done
      (no commit info)

Best regards,
-- 
Jens Axboe