[RESEND,1/6] nfsd: fix filecache lookup
diff mbox series

Message ID 20200106181808.562969-2-trond.myklebust@hammerspace.com
State New
Headers show
Series
  • Improve performance of containerised knfsd
Related show

Commit Message

Trond Myklebust Jan. 6, 2020, 6:18 p.m. UTC
If the lookup keeps finding a nfsd_file with an unhashed open file,
then retry once only.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfsd/filecache.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

J. Bruce Fields Jan. 21, 2020, 9:28 p.m. UTC | #1
On Mon, Jan 06, 2020 at 01:18:03PM -0500, Trond Myklebust wrote:
> If the lookup keeps finding a nfsd_file with an unhashed open file,
> then retry once only.

So, symptoms are a hang?

Should this be cc: stable, Fixes: 65294c1f2c5e ("nfsd: add a new struct
file caching facility to nfsd") ?

--b.

> 
> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
> ---
>  fs/nfsd/filecache.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
> index 32a9bf22ac08..0a3e5c2aac4b 100644
> --- a/fs/nfsd/filecache.c
> +++ b/fs/nfsd/filecache.c
> @@ -789,6 +789,7 @@ nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  	struct nfsd_file *nf, *new;
>  	struct inode *inode;
>  	unsigned int hashval;
> +	bool retry = true;
>  
>  	/* FIXME: skip this if fh_dentry is already set? */
>  	status = fh_verify(rqstp, fhp, S_IFREG,
> @@ -824,6 +825,11 @@ nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  
>  	/* Did construction of this file fail? */
>  	if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
> +		if (!retry) {
> +			status = nfserr_jukebox;
> +			goto out;
> +		}
> +		retry = false;
>  		nfsd_file_put_noref(nf);
>  		goto retry;
>  	}
> -- 
> 2.24.1
Trond Myklebust Jan. 21, 2020, 11:07 p.m. UTC | #2
On Tue, 2020-01-21 at 16:28 -0500, J. Bruce Fields wrote:
> On Mon, Jan 06, 2020 at 01:18:03PM -0500, Trond Myklebust wrote:
> > If the lookup keeps finding a nfsd_file with an unhashed open file,
> > then retry once only.
> 
> So, symptoms are a hang?
> 
> Should this be cc: stable, Fixes: 65294c1f2c5e ("nfsd: add a new
> struct
> file caching facility to nfsd") ?

I would recommend that we make it a stable fix, yes. We've hit it
internally, and I believe Chuck was hitting it as well.

Patch
diff mbox series

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 32a9bf22ac08..0a3e5c2aac4b 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -789,6 +789,7 @@  nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	struct nfsd_file *nf, *new;
 	struct inode *inode;
 	unsigned int hashval;
+	bool retry = true;
 
 	/* FIXME: skip this if fh_dentry is already set? */
 	status = fh_verify(rqstp, fhp, S_IFREG,
@@ -824,6 +825,11 @@  nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 
 	/* Did construction of this file fail? */
 	if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
+		if (!retry) {
+			status = nfserr_jukebox;
+			goto out;
+		}
+		retry = false;
 		nfsd_file_put_noref(nf);
 		goto retry;
 	}