From 424e67025cabb09ffa3110de5cd3558d937ee58d Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 2 Sep 2019 13:02:56 -0400 Subject: [PATCH] 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 Signed-off-by: Lance Shelton Signed-off-by: J. Bruce Fields --- fs/nfsd/netns.h | 4 ++++ fs/nfsd/nfs3xdr.c | 13 +++++++++---- fs/nfsd/nfs4proc.c | 14 ++++---------- fs/nfsd/nfsctl.c | 1 + fs/nfsd/nfssvc.c | 31 ++++++++++++++++++++++++++++++- 5 files changed, 48 insertions(+), 15 deletions(-) diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index bdfe5bcb3dcd0..9a4ef815fb8c1 100644 --- 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 fcf31822c74c0..86e5658651f10 100644 --- 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 cb51893ec1cd5..4e3e77b764115 100644 --- 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 3cf4f6aa48d60..33cbe2e5d937a 100644 --- 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 b944553c69276..3caaf5675259f 100644 --- 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; } -- 2.39.5