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From: Jeff Layton <jlayton@kernel.org>
To: trondmy@gmail.com, Chuck Lever <chuck.lever@oracle.com>
Cc: linux-nfs@vger.kernel.org
Subject: Re: [PATCH] nfsd: Handle EOPENSTALE correctly in the filecache
Date: Tue, 12 Sep 2023 06:44:40 -0400	[thread overview]
Message-ID: <eefec1ba89a5b70de5a0964e3d321a22ac86ab2d.camel@kernel.org> (raw)
In-Reply-To: <20230911183027.11372-1-trond.myklebust@hammerspace.com>

On Mon, 2023-09-11 at 14:30 -0400, trondmy@gmail.com wrote:
> From: Trond Myklebust <trond.myklebust@hammerspace.com>
> 
> The nfsd_open code handles EOPENSTALE correctly, by retrying the call to
> fh_verify() and __nfsd_open(). However the filecache just drops the
> error on the floor, and immediately returns nfserr_stale to the caller.
> 
> This patch ensures that we propagate the EOPENSTALE code back to
> nfsd_file_do_acquire, and that we handle it correctly.
> 
> Fixes: 65294c1f2c5e ("nfsd: add a new struct file caching facility to nfsd")
> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
> ---
>  fs/nfsd/filecache.c | 27 +++++++++++++++++++--------
>  fs/nfsd/vfs.c       | 28 +++++++++++++---------------
>  fs/nfsd/vfs.h       |  2 +-
>  3 files changed, 33 insertions(+), 24 deletions(-)
> 
> diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
> index ee9c923192e0..07bf219f9ae4 100644
> --- a/fs/nfsd/filecache.c
> +++ b/fs/nfsd/filecache.c
> @@ -989,22 +989,21 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  	unsigned char need = may_flags & NFSD_FILE_MAY_MASK;
>  	struct net *net = SVC_NET(rqstp);
>  	struct nfsd_file *new, *nf;
> -	const struct cred *cred;
> +	bool stale_retry = true;
>  	bool open_retry = true;
>  	struct inode *inode;
>  	__be32 status;
>  	int ret;
>  
> +retry:
>  	status = fh_verify(rqstp, fhp, S_IFREG,
>  				may_flags|NFSD_MAY_OWNER_OVERRIDE);
>  	if (status != nfs_ok)
>  		return status;
>  	inode = d_inode(fhp->fh_dentry);
> -	cred = get_current_cred();
>  
> -retry:
>  	rcu_read_lock();
> -	nf = nfsd_file_lookup_locked(net, cred, inode, need, want_gc);
> +	nf = nfsd_file_lookup_locked(net, current_cred(), inode, need, want_gc);
>  	rcu_read_unlock();
>  
>  	if (nf) {
> @@ -1026,7 +1025,7 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  
>  	rcu_read_lock();
>  	spin_lock(&inode->i_lock);
> -	nf = nfsd_file_lookup_locked(net, cred, inode, need, want_gc);
> +	nf = nfsd_file_lookup_locked(net, current_cred(), inode, need, want_gc);
>  	if (unlikely(nf)) {
>  		spin_unlock(&inode->i_lock);
>  		rcu_read_unlock();
> @@ -1058,6 +1057,7 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  			goto construction_err;
>  		}
>  		open_retry = false;
> +		fh_put(fhp);
>  		goto retry;
>  	}
>  	this_cpu_inc(nfsd_file_cache_hits);
> @@ -1074,7 +1074,6 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  		nfsd_file_check_write_error(nf);
>  		*pnf = nf;
>  	}
> -	put_cred(cred);
>  	trace_nfsd_file_acquire(rqstp, inode, may_flags, nf, status);
>  	return status;
>  
> @@ -1088,8 +1087,20 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  			status = nfs_ok;
>  			trace_nfsd_file_opened(nf, status);
>  		} else {
> -			status = nfsd_open_verified(rqstp, fhp, may_flags,
> -						    &nf->nf_file);
> +			ret = nfsd_open_verified(rqstp, fhp, may_flags,
> +						 &nf->nf_file);
> +			if (ret == -EOPENSTALE && stale_retry) {
> +				stale_retry = false;
> +				nfsd_file_unhash(nf);
> +				clear_and_wake_up_bit(NFSD_FILE_PENDING,
> +						      &nf->nf_flags);
> +				if (refcount_dec_and_test(&nf->nf_ref))
> +					nfsd_file_free(nf);
> +				nf = NULL;
> +				fh_put(fhp);
> +				goto retry;
> +			}
> +			status = nfserrno(ret);
>  			trace_nfsd_file_open(nf, status);
>  		}
>  	} else
> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> index 2c9074ab2315..98fa4fd0556d 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -823,7 +823,7 @@ int nfsd_open_break_lease(struct inode *inode, int access)
>   * and additional flags.
>   * N.B. After this call fhp needs an fh_put
>   */
> -static __be32
> +static int
>  __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
>  			int may_flags, struct file **filp)
>  {
> @@ -831,14 +831,12 @@ __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
>  	struct inode	*inode;
>  	struct file	*file;
>  	int		flags = O_RDONLY|O_LARGEFILE;
> -	__be32		err;
> -	int		host_err = 0;
> +	int		host_err = -EPERM;
>  
>  	path.mnt = fhp->fh_export->ex_path.mnt;
>  	path.dentry = fhp->fh_dentry;
>  	inode = d_inode(path.dentry);
>  
> -	err = nfserr_perm;
>  	if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
>  		goto out;
>  
> @@ -847,7 +845,7 @@ __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
>  
>  	host_err = nfsd_open_break_lease(inode, may_flags);
>  	if (host_err) /* NOMEM or WOULDBLOCK */
> -		goto out_nfserr;
> +		goto out;
>  
>  	if (may_flags & NFSD_MAY_WRITE) {
>  		if (may_flags & NFSD_MAY_READ)
> @@ -859,13 +857,13 @@ __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
>  	file = dentry_open(&path, flags, current_cred());
>  	if (IS_ERR(file)) {
>  		host_err = PTR_ERR(file);
> -		goto out_nfserr;
> +		goto out;
>  	}
>  
>  	host_err = ima_file_check(file, may_flags);
>  	if (host_err) {
>  		fput(file);
> -		goto out_nfserr;
> +		goto out;
>  	}
>  
>  	if (may_flags & NFSD_MAY_64BIT_COOKIE)
> @@ -874,10 +872,8 @@ __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
>  		file->f_mode |= FMODE_32BITHASH;
>  
>  	*filp = file;
> -out_nfserr:
> -	err = nfserrno(host_err);
>  out:
> -	return err;
> +	return host_err;
>  }
>  
>  __be32
> @@ -885,6 +881,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
>  		int may_flags, struct file **filp)
>  {
>  	__be32 err;
> +	int host_err;
>  	bool retried = false;
>  
>  	validate_process_creds();
> @@ -904,12 +901,13 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
>  retry:
>  	err = fh_verify(rqstp, fhp, type, may_flags);
>  	if (!err) {
> -		err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
> -		if (err == nfserr_stale && !retried) {
> +		host_err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
> +		if (host_err == -EOPENSTALE && !retried) {
>  			retried = true;
>  			fh_put(fhp);
>  			goto retry;
>  		}
> +		err = nfserrno(host_err);
>  	}
>  	validate_process_creds();
>  	return err;
> @@ -922,13 +920,13 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
>   * @may_flags: internal permission flags
>   * @filp: OUT: open "struct file *"
>   *
> - * Returns an nfsstat value in network byte order.
> + * Returns a posix error.
>   */
> -__be32
> +int
>  nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, int may_flags,
>  		   struct file **filp)
>  {
> -	__be32 err;
> +	int err;
>  
>  	validate_process_creds();
>  	err = __nfsd_open(rqstp, fhp, S_IFREG, may_flags, filp);
> diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
> index a6890ea7b765..e4b7207ef2e0 100644
> --- a/fs/nfsd/vfs.h
> +++ b/fs/nfsd/vfs.h
> @@ -104,7 +104,7 @@ __be32		nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  int 		nfsd_open_break_lease(struct inode *, int);
>  __be32		nfsd_open(struct svc_rqst *, struct svc_fh *, umode_t,
>  				int, struct file **);
> -__be32		nfsd_open_verified(struct svc_rqst *, struct svc_fh *,
> +int		nfsd_open_verified(struct svc_rqst *, struct svc_fh *,
>  				int, struct file **);
>  __be32		nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  				struct file *file, loff_t offset,

Looks reasonable.

Reviewed-by: Jeff Layton <jlayton@kernel.org>

  parent reply	other threads:[~2023-09-12 10:45 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-11 18:30 [PATCH] nfsd: Handle EOPENSTALE correctly in the filecache trondmy
2023-09-11 22:26 ` Chuck Lever
2023-09-12  0:58   ` Trond Myklebust
2023-09-12 10:44 ` Jeff Layton [this message]
2023-09-12 13:18   ` Chuck Lever

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