nfsd: Handle EOPENSTALE correctly in the filecache

[ Upstream commit d59b3515ab021e010fdc58a8f445ea62dd2f7f4c ]

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>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230911183027.11372-1-trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index ee9c923..07bf219 100644 (file)
--- 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 @@ retry:
 
        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 @@ wait_for_construction:
                        goto construction_err;
                }
                open_retry = false;
+               fh_put(fhp);
                goto retry;
        }
        this_cpu_inc(nfsd_file_cache_hits);
@@ -1074,7 +1074,6 @@ out:
                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 @@ open_file:
                        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 02f5fca..b24462e 100644 (file)
--- 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 @@ retry:
  * @may_flags: internal permission flags
  * @filp: OUT: open "struct file *"
  *
- * Returns an nfsstat value in network byte order.
+ * Returns zero on success, or a negative errno value.
  */
-__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 a6890ea..e3c2959 100644 (file)
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -104,8 +104,8 @@ __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, struct file **);
+int            nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp,
+                                  int may_flags, struct file **filp);
 __be32         nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
                                struct file *file, loff_t offset,
                                unsigned long *count,