nfs_lock.c revision 138430
175631Salfred/*- 275631Salfred * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved. 375631Salfred * 475631Salfred * Redistribution and use in source and binary forms, with or without 575631Salfred * modification, are permitted provided that the following conditions 675631Salfred * are met: 775631Salfred * 1. Redistributions of source code must retain the above copyright 875631Salfred * notice, this list of conditions and the following disclaimer. 975631Salfred * 2. Redistributions in binary form must reproduce the above copyright 1075631Salfred * notice, this list of conditions and the following disclaimer in the 1175631Salfred * documentation and/or other materials provided with the distribution. 1275631Salfred * 3. Berkeley Software Design Inc's name may not be used to endorse or 1375631Salfred * promote products derived from this software without specific prior 1475631Salfred * written permission. 1575631Salfred * 1675631Salfred * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 1775631Salfred * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1875631Salfred * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1975631Salfred * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 2075631Salfred * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2175631Salfred * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2275631Salfred * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2375631Salfred * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2475631Salfred * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2575631Salfred * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2675631Salfred * SUCH DAMAGE. 2775631Salfred * 2875631Salfred * from BSDI nfs_lock.c,v 2.4 1998/12/14 23:49:56 jch Exp 2975631Salfred */ 3075631Salfred 3183651Speter#include <sys/cdefs.h> 3283651Speter__FBSDID("$FreeBSD: head/sys/nfsclient/nfs_lock.c 138430 2004-12-06 08:31:32Z phk $"); 3383651Speter 3475631Salfred#include <sys/param.h> 3575631Salfred#include <sys/systm.h> 36138430Sphk#include <sys/conf.h> 3775631Salfred#include <sys/fcntl.h> 3876166Smarkm#include <sys/kernel.h> /* for hz */ 39114216Skan#include <sys/limits.h> 4076166Smarkm#include <sys/lock.h> 4175631Salfred#include <sys/malloc.h> 4276166Smarkm#include <sys/lockf.h> /* for hz */ /* Must come after sys/malloc.h */ 4375631Salfred#include <sys/mbuf.h> 4475631Salfred#include <sys/mount.h> 4575631Salfred#include <sys/namei.h> 4675631Salfred#include <sys/proc.h> 4776166Smarkm#include <sys/resourcevar.h> 4875631Salfred#include <sys/socket.h> 4976166Smarkm#include <sys/socket.h> 5075631Salfred#include <sys/unistd.h> 5175631Salfred#include <sys/vnode.h> 5275631Salfred 5375631Salfred#include <net/if.h> 5475631Salfred 55122698Salfred#include <rpc/rpcclnt.h> 56122698Salfred 5775631Salfred#include <nfs/rpcv2.h> 5875631Salfred#include <nfs/nfsproto.h> 5983651Speter#include <nfsclient/nfs.h> 6083651Speter#include <nfsclient/nfsmount.h> 6183651Speter#include <nfsclient/nfsnode.h> 6283651Speter#include <nfsclient/nfs_lock.h> 6383651Speter#include <nfsclient/nlminfo.h> 6475631Salfred 65138430SphkMALLOC_DEFINE(M_NFSLOCK, "NFS lock", "NFS lock request"); 66138430Sphk 67138430Sphkstatic int nfslockdans(struct thread *td, struct lockd_ans *ansp); 6875631Salfred/* 69138430Sphk * -------------------------------------------------------------------- 70138430Sphk * A miniature device driver which the userland uses to talk to us. 71138430Sphk * 72138430Sphk */ 73138430Sphk 74138430Sphkstatic struct cdev *nfslock_dev; 75138430Sphkstatic struct mtx nfslock_mtx; 76138430Sphkstatic int nfslock_isopen; 77138430Sphkstatic TAILQ_HEAD(,__lock_msg) nfslock_list; 78138430Sphk 79138430Sphkstatic int 80138430Sphknfslock_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 81138430Sphk{ 82138430Sphk int error; 83138430Sphk 84138430Sphk mtx_lock(&nfslock_mtx); 85138430Sphk if (!nfslock_isopen) { 86138430Sphk error = 0; 87138430Sphk nfslock_isopen = 1; 88138430Sphk } else { 89138430Sphk error = EOPNOTSUPP; 90138430Sphk } 91138430Sphk mtx_unlock(&nfslock_mtx); 92138430Sphk 93138430Sphk return (error); 94138430Sphk} 95138430Sphk 96138430Sphkstatic int 97138430Sphknfslock_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 98138430Sphk{ 99138430Sphk struct __lock_msg *lm; 100138430Sphk 101138430Sphk mtx_lock(&nfslock_mtx); 102138430Sphk nfslock_isopen = 0; 103138430Sphk while (!TAILQ_EMPTY(&nfslock_list)) { 104138430Sphk lm = TAILQ_FIRST(&nfslock_list); 105138430Sphk /* XXX: answer request */ 106138430Sphk TAILQ_REMOVE(&nfslock_list, lm, lm_link); 107138430Sphk free(lm, M_NFSLOCK); 108138430Sphk } 109138430Sphk mtx_unlock(&nfslock_mtx); 110138430Sphk return (0); 111138430Sphk} 112138430Sphk 113138430Sphkstatic int 114138430Sphknfslock_read(struct cdev *dev, struct uio *uio, int ioflag) 115138430Sphk{ 116138430Sphk int error; 117138430Sphk struct __lock_msg *lm; 118138430Sphk 119138430Sphk if (uio->uio_resid != sizeof *lm) 120138430Sphk return (EOPNOTSUPP); 121138430Sphk lm = NULL; 122138430Sphk error = 0; 123138430Sphk mtx_lock(&nfslock_mtx); 124138430Sphk while (TAILQ_EMPTY(&nfslock_list)) { 125138430Sphk error = msleep(&nfslock_list, &nfslock_mtx, PSOCK | PCATCH, 126138430Sphk "nfslockd", 0); 127138430Sphk if (error) 128138430Sphk break; 129138430Sphk } 130138430Sphk if (!error) { 131138430Sphk lm = TAILQ_FIRST(&nfslock_list); 132138430Sphk TAILQ_REMOVE(&nfslock_list, lm, lm_link); 133138430Sphk } 134138430Sphk mtx_unlock(&nfslock_mtx); 135138430Sphk if (!error) { 136138430Sphk error = uiomove(lm, sizeof *lm, uio); 137138430Sphk free(lm, M_NFSLOCK); 138138430Sphk } 139138430Sphk return (error); 140138430Sphk} 141138430Sphk 142138430Sphkstatic int 143138430Sphknfslock_write(struct cdev *dev, struct uio *uio, int ioflag) 144138430Sphk{ 145138430Sphk struct lockd_ans la; 146138430Sphk int error; 147138430Sphk 148138430Sphk if (uio->uio_resid != sizeof la) 149138430Sphk return (EOPNOTSUPP); 150138430Sphk error = uiomove(&la, sizeof la, uio); 151138430Sphk if (!error) 152138430Sphk error = nfslockdans(curthread, &la); 153138430Sphk return (error); 154138430Sphk} 155138430Sphk 156138430Sphkstatic int 157138430Sphknfslock_send(struct __lock_msg *lm) 158138430Sphk{ 159138430Sphk struct __lock_msg *lm2; 160138430Sphk int error; 161138430Sphk 162138430Sphk error = 0; 163138430Sphk lm2 = malloc(sizeof *lm2, M_NFSLOCK, M_WAITOK); 164138430Sphk mtx_lock(&nfslock_mtx); 165138430Sphk if (nfslock_isopen) { 166138430Sphk memcpy(lm2, lm, sizeof *lm2); 167138430Sphk TAILQ_INSERT_TAIL(&nfslock_list, lm2, lm_link); 168138430Sphk wakeup(&nfslock_list); 169138430Sphk } else { 170138430Sphk error = EOPNOTSUPP; 171138430Sphk } 172138430Sphk mtx_unlock(&nfslock_mtx); 173138430Sphk if (error) 174138430Sphk free(lm2, M_NFSLOCK); 175138430Sphk return (error); 176138430Sphk} 177138430Sphk 178138430Sphkstatic struct cdevsw nfslock_cdevsw = { 179138430Sphk .d_version = D_VERSION, 180138430Sphk .d_open = nfslock_open, 181138430Sphk .d_close = nfslock_close, 182138430Sphk .d_read = nfslock_read, 183138430Sphk .d_write = nfslock_write, 184138430Sphk .d_name = "nfslock" 185138430Sphk}; 186138430Sphk 187138430Sphkstatic int 188138430Sphknfslock_modevent(module_t mod __unused, int type, void *data __unused) 189138430Sphk{ 190138430Sphk 191138430Sphk switch (type) { 192138430Sphk case MOD_LOAD: 193138430Sphk if (bootverbose) 194138430Sphk printf("nfslock: pseudo-device\n"); 195138430Sphk mtx_init(&nfslock_mtx, "nfslock", NULL, MTX_DEF); 196138430Sphk TAILQ_INIT(&nfslock_list); 197138430Sphk nfslock_dev = make_dev(&nfslock_cdevsw, 0, 198138430Sphk UID_ROOT, GID_KMEM, 0600, _PATH_NFSLCKDEV); 199138430Sphk return (0); 200138430Sphk default: 201138430Sphk return (EOPNOTSUPP); 202138430Sphk } 203138430Sphk} 204138430Sphk 205138430SphkDEV_MODULE(nfslock, nfslock_modevent, NULL); 206138430SphkMODULE_VERSION(nfslock, 1); 207138430Sphk 208138430Sphk 209138430Sphk/* 21075631Salfred * XXX 21175631Salfred * We have to let the process know if the call succeeded. I'm using an extra 21283651Speter * field in the p_nlminfo field in the proc structure, as it is already for 21375631Salfred * lockd stuff. 21475631Salfred */ 21575631Salfred 21675631Salfred/* 21775631Salfred * nfs_advlock -- 21875631Salfred * NFS advisory byte-level locks. 21975631Salfred */ 22075631Salfredint 22183651Speternfs_dolock(struct vop_advlock_args *ap) 22275631Salfred{ 22375631Salfred LOCKD_MSG msg; 22483366Sjulian struct thread *td; 225138430Sphk struct vnode *vp; 226138430Sphk int error; 22775631Salfred struct flock *fl; 228138430Sphk int ioflg; 22983366Sjulian struct proc *p; 23075631Salfred 23183366Sjulian td = curthread; 23283366Sjulian p = td->td_proc; 23383366Sjulian 23475631Salfred vp = ap->a_vp; 23575631Salfred fl = ap->a_fl; 23675631Salfred 23775631Salfred /* 23875631Salfred * the NLM protocol doesn't allow the server to return an error 23982174Sache * on ranges, so we do it. 24075631Salfred */ 24182194Sache if (fl->l_whence != SEEK_END) { 24282213Sache if ((fl->l_whence != SEEK_CUR && fl->l_whence != SEEK_SET) || 24382204Sache fl->l_start < 0 || 24482204Sache (fl->l_len < 0 && 24582204Sache (fl->l_start == 0 || fl->l_start + fl->l_len < 0))) 24682194Sache return (EINVAL); 24782204Sache if (fl->l_len > 0 && 24882204Sache (fl->l_len - 1 > OFF_MAX - fl->l_start)) 24982194Sache return (EOVERFLOW); 25082194Sache } 25175631Salfred 25275631Salfred /* 25375631Salfred * Fill in the information structure. 25475631Salfred */ 25575631Salfred msg.lm_version = LOCKD_MSG_VERSION; 25675631Salfred msg.lm_msg_ident.pid = p->p_pid; 25775631Salfred /* 25875631Salfred * if there is no nfsowner table yet, allocate one. 25975631Salfred */ 26075631Salfred if (p->p_nlminfo == NULL) { 26175631Salfred MALLOC(p->p_nlminfo, struct nlminfo *, 262111119Simp sizeof(struct nlminfo), M_LOCKF, M_WAITOK | M_ZERO); 26375631Salfred p->p_nlminfo->pid_start = p->p_stats->p_start; 264114434Sdes timevaladd(&p->p_nlminfo->pid_start, &boottime); 26575631Salfred } 26675631Salfred msg.lm_msg_ident.pid_start = p->p_nlminfo->pid_start; 26775631Salfred msg.lm_msg_ident.msg_seq = ++(p->p_nlminfo->msg_seq); 26875631Salfred 26975631Salfred msg.lm_fl = *fl; 27075631Salfred msg.lm_wait = ap->a_flags & F_WAIT; 27175631Salfred msg.lm_getlk = ap->a_op == F_GETLK; 272100134Salfred bcopy(VFSTONFS(vp->v_mount)->nm_nam, &msg.lm_addr, 273100134Salfred min(sizeof msg.lm_addr, VFSTONFS(vp->v_mount)->nm_nam->sa_len)); 27475631Salfred msg.lm_fh_len = NFS_ISV3(vp) ? VTONFS(vp)->n_fhsize : NFSX_V2FH; 27575631Salfred bcopy(VTONFS(vp)->n_fhp, msg.lm_fh, msg.lm_fh_len); 27675631Salfred msg.lm_nfsv3 = NFS_ISV3(vp); 277101947Salfred cru2x(td->td_ucred, &msg.lm_cred); 27875631Salfred 27975631Salfred for (;;) { 280138430Sphk error = nfslock_send(&msg); 281138430Sphk if (error) 282138430Sphk return (error); 28375631Salfred 284138430Sphk /* Unlocks succeed immediately. */ 28575631Salfred if (fl->l_type == F_UNLCK) 286138430Sphk return (error); 28775631Salfred 28875631Salfred /* 28975631Salfred * retry after 20 seconds if we haven't gotten a responce yet. 29075631Salfred * This number was picked out of thin air... but is longer 29175631Salfred * then even a reasonably loaded system should take (at least 29283651Speter * on a local network). XXX Probably should use a back-off 29375631Salfred * scheme. 294116185Srwatson * 295116185Srwatson * XXX: No PCATCH here since we currently have no useful 296116185Srwatson * way to signal to the userland rpc.lockd that the request 297116185Srwatson * has been aborted. Once the rpc.lockd implementation 298116185Srwatson * can handle aborts, and we report them properly, 299116185Srwatson * PCATCH can be put back. In the mean time, if we did 300116185Srwatson * permit aborting, the lock attempt would "get lost" 301116185Srwatson * and the lock would get stuck in the locked state. 30275631Salfred */ 303115415Srwatson error = tsleep(p->p_nlminfo, PUSER, "lockd", 20*hz); 304107104Salfred if (error != 0) { 30575631Salfred if (error == EWOULDBLOCK) { 30675631Salfred /* 30775631Salfred * We timed out, so we rewrite the request 30875631Salfred * to the fifo, but only if it isn't already 30975631Salfred * full. 31075631Salfred */ 31175631Salfred ioflg |= IO_NDELAY; 31275631Salfred continue; 31375631Salfred } 31475631Salfred 31575631Salfred break; 31675631Salfred } 31775631Salfred 31875631Salfred if (msg.lm_getlk && p->p_nlminfo->retcode == 0) { 31975631Salfred if (p->p_nlminfo->set_getlk_pid) { 32075631Salfred fl->l_pid = p->p_nlminfo->getlk_pid; 32175631Salfred } else { 32275631Salfred fl->l_type = F_UNLCK; 32375631Salfred } 32475631Salfred } 32575631Salfred error = p->p_nlminfo->retcode; 32675631Salfred break; 32775631Salfred } 32875631Salfred 329138430Sphk return (error); 33075631Salfred} 33175631Salfred 33275631Salfred/* 33375631Salfred * nfslockdans -- 33475631Salfred * NFS advisory byte-level locks answer from the lock daemon. 33575631Salfred */ 336138430Sphkstatic int 33786363Srwatsonnfslockdans(struct thread *td, struct lockd_ans *ansp) 33875631Salfred{ 33986363Srwatson struct proc *targetp; 34075631Salfred int error; 34175631Salfred 34275631Salfred /* Let root, or someone who once was root (lockd generally 34383651Speter * switches to the daemon uid once it is done setting up) make 34477183Srwatson * this call. 34577183Srwatson * 34677183Srwatson * XXX This authorization check is probably not right. 34775631Salfred */ 34893593Sjhb if ((error = suser(td)) != 0 && 34991406Sjhb td->td_ucred->cr_svuid != 0) 35075631Salfred return (error); 35175631Salfred 35275631Salfred /* the version should match, or we're out of sync */ 35375631Salfred if (ansp->la_vers != LOCKD_ANS_VERSION) 35475631Salfred return (EINVAL); 35575631Salfred 35675631Salfred /* Find the process, set its return errno and wake it up. */ 35786363Srwatson if ((targetp = pfind(ansp->la_msg_ident.pid)) == NULL) 35875631Salfred return (ESRCH); 35975631Salfred 36083651Speter /* verify the pid hasn't been reused (if we can), and it isn't waiting 36175631Salfred * for an answer from a more recent request. We return an EPIPE if 36275631Salfred * the match fails, because we've already used ESRCH above, and this 36375631Salfred * is sort of like writing on a pipe after the reader has closed it. 36475631Salfred */ 36586363Srwatson if (targetp->p_nlminfo == NULL || 36675631Salfred ((ansp->la_msg_ident.msg_seq != -1) && 36786363Srwatson (timevalcmp(&targetp->p_nlminfo->pid_start, 36875631Salfred &ansp->la_msg_ident.pid_start, !=) || 36986363Srwatson targetp->p_nlminfo->msg_seq != ansp->la_msg_ident.msg_seq))) { 37086363Srwatson PROC_UNLOCK(targetp); 37175631Salfred return (EPIPE); 37277563Sjake } 37375631Salfred 37486363Srwatson targetp->p_nlminfo->retcode = ansp->la_errno; 37586363Srwatson targetp->p_nlminfo->set_getlk_pid = ansp->la_set_getlk_pid; 37686363Srwatson targetp->p_nlminfo->getlk_pid = ansp->la_getlk_pid; 37775631Salfred 378107104Salfred wakeup(targetp->p_nlminfo); 37975631Salfred 38086363Srwatson PROC_UNLOCK(targetp); 38175631Salfred return (0); 38275631Salfred} 383138430Sphk 384