From owner-dev-commits-src-all@freebsd.org Fri Apr 23 22:28:51 2021 Return-Path: Delivered-To: dev-commits-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id AFDF55E0DE7; Fri, 23 Apr 2021 22:28:51 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4FRpq74T5fz3PYQ; Fri, 23 Apr 2021 22:28:51 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 7D4EF15233; Fri, 23 Apr 2021 22:28:51 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 13NMSpbC007604; Fri, 23 Apr 2021 22:28:51 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 13NMSpI6007603; Fri, 23 Apr 2021 22:28:51 GMT (envelope-from git) Date: Fri, 23 Apr 2021 22:28:51 GMT Message-Id: <202104232228.13NMSpI6007603@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Rick Macklem Subject: git: 4281bfec3628 - main - nfsd: fix session slot handling for failed callbacks MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: rmacklem X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 4281bfec36285e2212f41568459c077bf4dbd91c Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Apr 2021 22:28:51 -0000 The branch main has been updated by rmacklem: URL: https://cgit.FreeBSD.org/src/commit/?id=4281bfec36285e2212f41568459c077bf4dbd91c commit 4281bfec36285e2212f41568459c077bf4dbd91c Author: Rick Macklem AuthorDate: 2021-04-23 22:24:47 +0000 Commit: Rick Macklem CommitDate: 2021-04-23 22:24:47 +0000 nfsd: fix session slot handling for failed callbacks When the NFSv4.1/4.2 server does a callback to a client on the back channel, it will use a session slot in the back channel session. If the back channel has failed, the callback will fail and, without this patch, the session slot will not be released. As more callbacks are attempted, all session slots can become busy and then the nfsd thread gets stuck waiting for a back channel session slot. This patch frees the session slot upon callback failure to avoid this problem. Without this patch, the problem can be avoided by leaving delegations disabled in the NFS server. MFC after: 2 weeks --- sys/fs/nfsserver/nfs_nfsdstate.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/sys/fs/nfsserver/nfs_nfsdstate.c b/sys/fs/nfsserver/nfs_nfsdstate.c index 60647ab288d8..430f09844b83 100644 --- a/sys/fs/nfsserver/nfs_nfsdstate.c +++ b/sys/fs/nfsserver/nfs_nfsdstate.c @@ -166,7 +166,8 @@ static int nfsrv_docallback(struct nfsclient *clp, int procnum, nfsv4stateid_t *stateidp, int trunc, fhandle_t *fhp, struct nfsvattr *nap, nfsattrbit_t *attrbitp, int laytype, NFSPROC_T *p); static int nfsrv_cbcallargs(struct nfsrv_descript *nd, struct nfsclient *clp, - uint32_t callback, int op, const char *optag, struct nfsdsession **sepp); + uint32_t callback, int op, const char *optag, struct nfsdsession **sepp, + int *slotposp); static u_int32_t nfsrv_nextclientindex(void); static u_int32_t nfsrv_nextstateindex(struct nfsclient *clp); static void nfsrv_markstable(struct nfsclient *clp); @@ -201,7 +202,7 @@ static void nfsrv_unlocklf(struct nfslockfile *lfp); static struct nfsdsession *nfsrv_findsession(uint8_t *sessionid); static int nfsrv_freesession(struct nfsdsession *sep, uint8_t *sessionid); static int nfsv4_setcbsequence(struct nfsrv_descript *nd, struct nfsclient *clp, - int dont_replycache, struct nfsdsession **sepp); + int dont_replycache, struct nfsdsession **sepp, int *slotposp); static int nfsv4_getcbsession(struct nfsclient *clp, struct nfsdsession **sepp); static int nfsrv_addlayout(struct nfsrv_descript *nd, struct nfslayout **lypp, nfsv4stateid_t *stateidp, char *layp, int *layoutlenp, NFSPROC_T *p); @@ -4434,7 +4435,7 @@ nfsrv_docallback(struct nfsclient *clp, int procnum, nfsv4stateid_t *stateidp, u_int32_t *tl; struct nfsrv_descript *nd; struct ucred *cred; - int error = 0; + int error = 0, slotpos; u_int32_t callback; struct nfsdsession *sep = NULL; uint64_t tval; @@ -4492,7 +4493,7 @@ nfsrv_docallback(struct nfsclient *clp, int procnum, nfsv4stateid_t *stateidp, if (procnum == NFSV4OP_CBGETATTR) { nd->nd_procnum = NFSV4PROC_CBCOMPOUND; error = nfsrv_cbcallargs(nd, clp, callback, NFSV4OP_CBGETATTR, - "CB Getattr", &sep); + "CB Getattr", &sep, &slotpos); if (error != 0) { m_freem(nd->nd_mreq); goto errout; @@ -4502,7 +4503,7 @@ nfsrv_docallback(struct nfsclient *clp, int procnum, nfsv4stateid_t *stateidp, } else if (procnum == NFSV4OP_CBRECALL) { nd->nd_procnum = NFSV4PROC_CBCOMPOUND; error = nfsrv_cbcallargs(nd, clp, callback, NFSV4OP_CBRECALL, - "CB Recall", &sep); + "CB Recall", &sep, &slotpos); if (error != 0) { m_freem(nd->nd_mreq); goto errout; @@ -4521,7 +4522,7 @@ nfsrv_docallback(struct nfsclient *clp, int procnum, nfsv4stateid_t *stateidp, NFSD_DEBUG(4, "docallback layout recall\n"); nd->nd_procnum = NFSV4PROC_CBCOMPOUND; error = nfsrv_cbcallargs(nd, clp, callback, - NFSV4OP_CBLAYOUTRECALL, "CB Reclayout", &sep); + NFSV4OP_CBLAYOUTRECALL, "CB Reclayout", &sep, &slotpos); NFSD_DEBUG(4, "aft cbcallargs=%d\n", error); if (error != 0) { m_freem(nd->nd_mreq); @@ -4570,6 +4571,8 @@ nfsrv_docallback(struct nfsclient *clp, int procnum, nfsv4stateid_t *stateidp, if (clp->lc_req.nr_client == NULL) { if ((clp->lc_flags & LCL_NFSV41) != 0) { error = ECONNREFUSED; + if (procnum != NFSV4PROC_CBNULL) + nfsv4_freeslot(&sep->sess_cbsess, slotpos); nfsrv_freesession(sep, NULL); } else if (nd->nd_procnum == NFSV4PROC_CBNULL) error = newnfs_connect(NULL, &clp->lc_req, cred, @@ -4601,6 +4604,8 @@ nfsrv_docallback(struct nfsclient *clp, int procnum, nfsv4stateid_t *stateidp, error = ECONNREFUSED; } NFSD_DEBUG(4, "aft newnfs_request=%d\n", error); + if (error != 0 && procnum != NFSV4PROC_CBNULL) + nfsv4_freeslot(&sep->sess_cbsess, slotpos); nfsrv_freesession(sep, NULL); } else error = newnfs_request(nd, NULL, clp, &clp->lc_req, @@ -4663,7 +4668,8 @@ errout: */ static int nfsrv_cbcallargs(struct nfsrv_descript *nd, struct nfsclient *clp, - uint32_t callback, int op, const char *optag, struct nfsdsession **sepp) + uint32_t callback, int op, const char *optag, struct nfsdsession **sepp, + int *slotposp) { uint32_t *tl; int error, len; @@ -4679,7 +4685,7 @@ nfsrv_cbcallargs(struct nfsrv_descript *nd, struct nfsclient *clp, *tl++ = txdr_unsigned(callback); *tl++ = txdr_unsigned(2); *tl = txdr_unsigned(NFSV4OP_CBSEQUENCE); - error = nfsv4_setcbsequence(nd, clp, 1, sepp); + error = nfsv4_setcbsequence(nd, clp, 1, sepp, slotposp); if (error != 0) return (error); NFSM_BUILD(tl, u_int32_t *, NFSX_UNSIGNED); @@ -6599,11 +6605,11 @@ nfsrv_teststateid(struct nfsrv_descript *nd, nfsv4stateid_t *stateidp, */ static int nfsv4_setcbsequence(struct nfsrv_descript *nd, struct nfsclient *clp, - int dont_replycache, struct nfsdsession **sepp) + int dont_replycache, struct nfsdsession **sepp, int *slotposp) { struct nfsdsession *sep; uint32_t *tl, slotseq = 0; - int maxslot, slotpos; + int maxslot; uint8_t sessionid[NFSX_V4SESSIONID]; int error; @@ -6611,7 +6617,7 @@ nfsv4_setcbsequence(struct nfsrv_descript *nd, struct nfsclient *clp, if (error != 0) return (error); sep = *sepp; - (void)nfsv4_sequencelookup(NULL, &sep->sess_cbsess, &slotpos, &maxslot, + (void)nfsv4_sequencelookup(NULL, &sep->sess_cbsess, slotposp, &maxslot, &slotseq, sessionid); KASSERT(maxslot >= 0, ("nfsv4_setcbsequence neg maxslot")); @@ -6621,7 +6627,7 @@ nfsv4_setcbsequence(struct nfsrv_descript *nd, struct nfsclient *clp, tl += NFSX_V4SESSIONID / NFSX_UNSIGNED; nd->nd_slotseq = tl; *tl++ = txdr_unsigned(slotseq); - *tl++ = txdr_unsigned(slotpos); + *tl++ = txdr_unsigned(*slotposp); *tl++ = txdr_unsigned(maxslot); if (dont_replycache == 0) *tl++ = newnfs_true;