[PATCH v2] nvmet-file: fix nvmet_file_flush() always returning an error

[PATCH v2] nvmet-file: fix nvmet_file_flush() always returning an error

[Logan Gunthorpe]

Presently, nvmet_file_flush() always returns a call to
errno_to_nvme_status() but that helper doesn't take into account the
case when errno=0. So nvmet_file_flush() always returns an error code.

All other callers of errno_to_nvme_status() check for success before
calling it.

To fix this, ensure errno_to_nvme_status() returns success if the
errno is zero. This should prevent future mistakes like this from
happening.

Fixes: c6aa3542e010 ("nvmet: add error log support for file backend")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
 drivers/nvme/target/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 7734a6acff85..e1f03cfc6675 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -43,6 +43,9 @@ inline u16 errno_to_nvme_status(struct nvmet_req *req, int errno)
 	u16 status;
 
 	switch (errno) {
+	case 0:
+		status = NVME_SC_SUCCESS;
+		break;
 	case -ENOSPC:
 		req->error_loc = offsetof(struct nvme_rw_command, length);
 		status = NVME_SC_CAP_EXCEEDED | NVME_SC_DNR;
-- 
2.20.1

Re: [PATCH v2] nvmet-file: fix nvmet_file_flush() always returning an error

[Sagi Grimberg]

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

Re: [PATCH v2] nvmet-file: fix nvmet_file_flush() always returning an error

[Chaitanya Kulkarni]

On 07/15/2019 03:17 PM, Logan Gunthorpe wrote:
> Presently, nvmet_file_flush() always returns a call to
> errno_to_nvme_status() but that helper doesn't take into account the
> case when errno=0. So nvmet_file_flush() always returns an error code.
>
> All other callers of errno_to_nvme_status() check for success before
> calling it.
>
> To fix this, ensure errno_to_nvme_status() returns success if the
> errno is zero. This should prevent future mistakes like this from
> happening.
>
> Fixes: c6aa3542e010 ("nvmet: add error log support for file backend")
> Signed-off-by: Logan Gunthorpe<logang@deltatee.com>
> Cc: Chaitanya Kulkarni<chaitanya.kulkarni@wdc.com>

Thanks for the fix Logan, errno_to_nvme_status() needs to be only called 
in the case of error. Clearly bad example of calling function withing 
function.

Looks good to me.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>