nfsd: Support the server resetting the boot verifier

Add support to allow the server to reset the boot verifier in order to
force clients to resend I/O after a timeout failure.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index bdfe5bcb3dcd0430a6a33f0738a41be75eb157dc..9a4ef815fb8c1a29cc5ba046b3ce170707aefd11 100644 (file)
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -104,6 +104,7 @@ struct nfsd_net {
 
        /* Time of server startup */
        struct timespec64 nfssvc_boot;
+       seqlock_t boot_lock;
 
        /*
         * Max number of connections this nfsd container will allow. Defaults
@@ -179,4 +180,7 @@ struct nfsd_net {
 extern void nfsd_netns_free_versions(struct nfsd_net *nn);
 
 extern unsigned int nfsd_net_id;
+
+void nfsd_copy_boot_verifier(__be32 verf[2], struct nfsd_net *nn);
+void nfsd_reset_boot_verifier(struct nfsd_net *nn);
 #endif /* __NFSD_NETNS_H__ */

diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index fcf31822c74c0b6e04616e45fbe915eacd9fc3ac..86e5658651f1066e359949571deb0c8ee9eb0a77 100644 (file)
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -27,6 +27,7 @@ static u32    nfs3_ftypes[] = {
        NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
 };
 
+
 /*
  * XDR functions for basic NFS types
  */
@@ -751,14 +752,16 @@ nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p)
 {
        struct nfsd3_writeres *resp = rqstp->rq_resp;
        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+       __be32 verf[2];
 
        p = encode_wcc_data(rqstp, p, &resp->fh);
        if (resp->status == 0) {
                *p++ = htonl(resp->count);
                *p++ = htonl(resp->committed);
                /* unique identifier, y2038 overflow can be ignored */
-               *p++ = htonl((u32)nn->nfssvc_boot.tv_sec);
-               *p++ = htonl(nn->nfssvc_boot.tv_nsec);
+               nfsd_copy_boot_verifier(verf, nn);
+               *p++ = verf[0];
+               *p++ = verf[1];
        }
        return xdr_ressize_check(rqstp, p);
 }
@@ -1125,13 +1128,15 @@ nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p)
 {
        struct nfsd3_commitres *resp = rqstp->rq_resp;
        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+       __be32 verf[2];
 
        p = encode_wcc_data(rqstp, p, &resp->fh);
        /* Write verifier */
        if (resp->status == 0) {
                /* unique identifier, y2038 overflow can be ignored */
-               *p++ = htonl((u32)nn->nfssvc_boot.tv_sec);
-               *p++ = htonl(nn->nfssvc_boot.tv_nsec);
+               nfsd_copy_boot_verifier(verf, nn);
+               *p++ = verf[0];
+               *p++ = verf[1];
        }
        return xdr_ressize_check(rqstp, p);
 }

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index cb51893ec1cd515c37b2bee16a87262a27345436..4e3e77b7641157ea6425535319500eb87dd7546b 100644 (file)
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -568,17 +568,11 @@ nfsd4_access(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 
 static void gen_boot_verifier(nfs4_verifier *verifier, struct net *net)
 {
-       __be32 verf[2];
-       struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+       __be32 *verf = (__be32 *)verifier->data;
 
-       /*
-        * This is opaque to client, so no need to byte-swap. Use
-        * __force to keep sparse happy. y2038 time_t overflow is
-        * irrelevant in this usage.
-        */
-       verf[0] = (__force __be32)nn->nfssvc_boot.tv_sec;
-       verf[1] = (__force __be32)nn->nfssvc_boot.tv_nsec;
-       memcpy(verifier->data, verf, sizeof(verifier->data));
+       BUILD_BUG_ON(2*sizeof(*verf) != sizeof(verifier->data));
+
+       nfsd_copy_boot_verifier(verf, net_generic(net, nfsd_net_id));
 }
 
 static __be32

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 3cf4f6aa48d605499b9b8b766084a50661e7d3a8..33cbe2e5d937aafb4492ac4b2535140d0e1969f1 100644 (file)
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1477,6 +1477,7 @@ static __net_init int nfsd_init_net(struct net *net)
 
        atomic_set(&nn->ntf_refcnt, 0);
        init_waitqueue_head(&nn->ntf_wq);
+       seqlock_init(&nn->boot_lock);
 
        mnt =  vfs_kern_mount(&nfsd_fs_type, SB_KERNMOUNT, "nfsd", NULL);
        if (IS_ERR(mnt)) {

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index b944553c69276aabe9c8b17d58a86b5266a7446e..3caaf5675259fa6cc64758cc5cd8cca7d1306353 100644 (file)
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -344,6 +344,35 @@ static bool nfsd_needs_lockd(struct nfsd_net *nn)
        return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST);
 }
 
+void nfsd_copy_boot_verifier(__be32 verf[2], struct nfsd_net *nn)
+{
+       int seq = 0;
+
+       do {
+               read_seqbegin_or_lock(&nn->boot_lock, &seq);
+               /*
+                * This is opaque to client, so no need to byte-swap. Use
+                * __force to keep sparse happy. y2038 time_t overflow is
+                * irrelevant in this usage
+                */
+               verf[0] = (__force __be32)nn->nfssvc_boot.tv_sec;
+               verf[1] = (__force __be32)nn->nfssvc_boot.tv_nsec;
+       } while (need_seqretry(&nn->boot_lock, seq));
+       done_seqretry(&nn->boot_lock, seq);
+}
+
+void nfsd_reset_boot_verifier_locked(struct nfsd_net *nn)
+{
+       ktime_get_real_ts64(&nn->nfssvc_boot);
+}
+
+void nfsd_reset_boot_verifier(struct nfsd_net *nn)
+{
+       write_seqlock(&nn->boot_lock);
+       nfsd_reset_boot_verifier_locked(nn);
+       write_sequnlock(&nn->boot_lock);
+}
+
 static int nfsd_startup_net(int nrservs, struct net *net, const struct cred *cred)
 {
        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
@@ -596,7 +625,7 @@ int nfsd_create_serv(struct net *net)
 #endif
        }
        atomic_inc(&nn->ntf_refcnt);
-       ktime_get_real_ts64(&nn->nfssvc_boot); /* record boot time */
+       nfsd_reset_boot_verifier(nn);
        return 0;
 }