Re: [SMBDIRECT][PATCH] missing rc checks while waiting for SMB3 over RDMA events

From: Steve French
Date: Tue Jun 22 2021 - 13:09:46 EST


patch updated with Tom's suggestions - let me know if I have missed anything.


On Tue, Jun 22, 2021 at 10:18 AM Tom Talpey <tom@xxxxxxxxxx> wrote:
>
> On 6/21/2021 5:32 PM, Steve French wrote:
> > There were two places where we weren't checking for error
> > (e.g. ERESTARTSYS) while waiting for rdma resolution.
> >
> > Addresses-Coverity: 1462165 ("Unchecked return value")
> > Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
> >
> > diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
> > index 10dfe5006792..ae07732f750f 100644
> > --- a/fs/cifs/smbdirect.c
> > +++ b/fs/cifs/smbdirect.c
> > @@ -572,8 +572,11 @@ static struct rdma_cm_id *smbd_create_id(
> > log_rdma_event(ERR, "rdma_resolve_addr() failed %i\n", rc);
> > goto out;
> > }
> > - wait_for_completion_interruptible_timeout(
> > + rc = wait_for_completion_interruptible_timeout(
> > &info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT));
> > + /* -ERESTARTSYS, returned when interrupted, is the only rc mentioned */
>
> Suggest the same comment text as the one below, this one seems uncertain.
>
> > + if (rc < 0)
> > + goto out;
> > rc = info->ri_rc;
> > if (rc) {
> > log_rdma_event(ERR, "rdma_resolve_addr() completed %i\n", rc);
> > @@ -586,8 +589,10 @@ static struct rdma_cm_id *smbd_create_id(
> > log_rdma_event(ERR, "rdma_resolve_route() failed %i\n", rc);
> > goto out;
> > }
> > - wait_for_completion_interruptible_timeout(
> > + rc = wait_for_completion_interruptible_timeout(
> > &info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT));
> > + if (rc < 0) /* e.g. if interrupted and returns -ERESTARTSYS */
>
> delete "and"?
>
> > + goto out
>
> Missing a semicolon. ^^^
>
> > rc = info->ri_rc;
> > if (rc) {
> > log_rdma_event(ERR, "rdma_resolve_route() completed %i\n", rc);
> >
> >
>
> One meta-comment. There's no message logged for these ERESTARTSYS cases.
> That might be confusing in the log, if they lead to failure.
>
> Reviewed-By: Tom Talpey <tom@xxxxxxxxxx>
>
> Tom.



--
Thanks,

Steve
From 0555b221528e9cb11f5766dcdee19c809187e42e Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Mon, 21 Jun 2021 16:25:20 -0500
Subject: [PATCH] smbdirect: missing rc checks while waiting for rdma events

There were two places where we weren't checking for error
(e.g. ERESTARTSYS) while waiting for rdma resolution.

Addresses-Coverity: 1462165 ("Unchecked return value")
Reviewed-by: Tom Talpey <tom@xxxxxxxxxx>
Reviewed-by: Long Li <longli@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/cifs/smbdirect.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index 10dfe5006792..31ef64eb7fbb 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -572,8 +572,13 @@ static struct rdma_cm_id *smbd_create_id(
log_rdma_event(ERR, "rdma_resolve_addr() failed %i\n", rc);
goto out;
}
- wait_for_completion_interruptible_timeout(
+ rc = wait_for_completion_interruptible_timeout(
&info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT));
+ /* e.g. if interrupted returns -ERESTARTSYS */
+ if (rc < 0) {
+ log_rdma_event(ERR, "rdma_resolve_addr timeout rc: %i\n", rc);
+ goto out;
+ }
rc = info->ri_rc;
if (rc) {
log_rdma_event(ERR, "rdma_resolve_addr() completed %i\n", rc);
@@ -586,8 +591,13 @@ static struct rdma_cm_id *smbd_create_id(
log_rdma_event(ERR, "rdma_resolve_route() failed %i\n", rc);
goto out;
}
- wait_for_completion_interruptible_timeout(
+ rc = wait_for_completion_interruptible_timeout(
&info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT));
+ /* e.g. if interrupted returns -ERESTARTSYS */
+ if (rc < 0) {
+ log_rdma_event(ERR, "rdma_resolve_addr timeout rc: %i\n", rc);
+ goto out;
+ }
rc = info->ri_rc;
if (rc) {
log_rdma_event(ERR, "rdma_resolve_route() completed %i\n", rc);
--
2.30.2