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

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

[Logan Gunthorpe]

errno_to_nvme_status() doesn't take into account the case
when errno=0, all other use cases only call it if there is actually
an error.

Presently, nvmet_file_flush() always returns a call to
errno_to_nvme_status() so, even if it is successful, it will
return NVME_SC_INTERNAL.

This bug was found while trying to get the existing blktests to pass.

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/io-cmd-file.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
index 05453f5d1448..fec17c66b8cd 100644
--- a/drivers/nvme/target/io-cmd-file.c
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -261,7 +261,13 @@ static void nvmet_file_execute_rw(struct nvmet_req *req)
 
 u16 nvmet_file_flush(struct nvmet_req *req)
 {
-	return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1));
+	int ret;
+
+	ret = vfs_fsync(req->ns->file, 1);
+	if (ret)
+		return errno_to_nvme_status(req, ret);
+
+	return NVME_SC_SUCCESS;
 }
 
 static void nvmet_file_flush_work(struct work_struct *w)
-- 
2.20.1

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

[Sagi Grimberg]

Looks good,

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

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

[Christoph Hellwig]

On Fri, Jul 12, 2019 at 04:42:07PM -0600, Logan Gunthorpe wrote:
> errno_to_nvme_status() doesn't take into account the case
> when errno=0, all other use cases only call it if there is actually
> an error.

Might it make more sense to handle 0 in errno_to_nvme_status to avoid
future problems like this one as well?  That would also match the
similar blk_to_nvme_status function better.

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

[Logan Gunthorpe]

On 2019-07-13 1:26 a.m., Christoph Hellwig wrote:
> On Fri, Jul 12, 2019 at 04:42:07PM -0600, Logan Gunthorpe wrote:
>> errno_to_nvme_status() doesn't take into account the case
>> when errno=0, all other use cases only call it if there is actually
>> an error.
> 
> Might it make more sense to handle 0 in errno_to_nvme_status to avoid
> future problems like this one as well?  That would also match the
> similar blk_to_nvme_status function better.

Sure, I'll send a v2 with that approach next week.

I had assumed that it was done this way for performance reasons so I
followed the way it was done in the other call sites.

Logan