2022-11-12 20:08:17

by Chuck Lever III

Subject: [PATCH] NFSD: Fix trace_nfsd_fh_verify_err() crasher

Now that the nfsd_fh_verify_err() tracepoint is always called on
error, it needs to handle cases where the filehandle is not yet
fully formed.

Fixes: 93c128e709ae ("nfsd: ensure we always call fh_verify_error tracepoint")
Signed-off-by: Chuck Lever <[email protected]>
---
fs/nfsd/trace.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index ef01ecd3eec6..331a33a8f1f8 100644
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -254,7 +254,10 @@ TRACE_EVENT_CONDITION(nfsd_fh_verify_err,
rqstp->rq_xprt->xpt_remotelen);
__entry->xid = be32_to_cpu(rqstp->rq_xid);
__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
- __entry->inode = d_inode(fhp->fh_dentry);
+ if (fhp->fh_dentry)
+ __entry->inode = d_inode(fhp->fh_dentry);
+ else
+ __entry->inode = NULL;
__entry->type = type;
__entry->access = access;
__entry->error = be32_to_cpu(error);

2022-11-14 11:38:31

by Jeff Layton

Subject: Re: [PATCH] NFSD: Fix trace_nfsd_fh_verify_err() crasher

On Sat, 2022-11-12 at 15:06 -0500, Chuck Lever wrote:
> Now that the nfsd_fh_verify_err() tracepoint is always called on
> error, it needs to handle cases where the filehandle is not yet
> fully formed.
>
> Fixes: 93c128e709ae ("nfsd: ensure we always call fh_verify_error tracepoint")
> Signed-off-by: Chuck Lever <[email protected]>
> ---
> fs/nfsd/trace.h | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
> index ef01ecd3eec6..331a33a8f1f8 100644
> --- a/fs/nfsd/trace.h
> +++ b/fs/nfsd/trace.h
> @@ -254,7 +254,10 @@ TRACE_EVENT_CONDITION(nfsd_fh_verify_err,
> rqstp->rq_xprt->xpt_remotelen);
> __entry->xid = be32_to_cpu(rqstp->rq_xid);
> __entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
> - __entry->inode = d_inode(fhp->fh_dentry);
> + if (fhp->fh_dentry)
> + __entry->inode = d_inode(fhp->fh_dentry);
> + else
> + __entry->inode = NULL;
> __entry->type = type;
> __entry->access = access;
> __entry->error = be32_to_cpu(error);
>

Doh!

Reviewed-by: Jeff Layton <[email protected]>