nfs_lock.c revision 151695
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 151695 2005-10-26 07:18:37Z glebius $"); 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 65151695Sglebiusextern void (*nlminfo_release_p)(struct proc *p); 66151695Sglebius 67138430SphkMALLOC_DEFINE(M_NFSLOCK, "NFS lock", "NFS lock request"); 68151695SglebiusMALLOC_DEFINE(M_NLMINFO, "nlminfo", "NFS lock process structure"); 69138430Sphk 70138430Sphkstatic int nfslockdans(struct thread *td, struct lockd_ans *ansp); 71151695Sglebiusstatic void nlminfo_release(struct proc *p); 7275631Salfred/* 73138430Sphk * -------------------------------------------------------------------- 74138430Sphk * A miniature device driver which the userland uses to talk to us. 75138430Sphk * 76138430Sphk */ 77138430Sphk 78138430Sphkstatic struct cdev *nfslock_dev; 79138430Sphkstatic struct mtx nfslock_mtx; 80138430Sphkstatic int nfslock_isopen; 81138430Sphkstatic TAILQ_HEAD(,__lock_msg) nfslock_list; 82138430Sphk 83138430Sphkstatic int 84138430Sphknfslock_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 85138430Sphk{ 86138430Sphk int error; 87138430Sphk 88138430Sphk mtx_lock(&nfslock_mtx); 89138430Sphk if (!nfslock_isopen) { 90138430Sphk error = 0; 91138430Sphk nfslock_isopen = 1; 92138430Sphk } else { 93138430Sphk error = EOPNOTSUPP; 94138430Sphk } 95138430Sphk mtx_unlock(&nfslock_mtx); 96138430Sphk 97138430Sphk return (error); 98138430Sphk} 99138430Sphk 100138430Sphkstatic int 101138430Sphknfslock_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 102138430Sphk{ 103138430Sphk struct __lock_msg *lm; 104138430Sphk 105138430Sphk mtx_lock(&nfslock_mtx); 106138430Sphk nfslock_isopen = 0; 107138430Sphk while (!TAILQ_EMPTY(&nfslock_list)) { 108138430Sphk lm = TAILQ_FIRST(&nfslock_list); 109138430Sphk /* XXX: answer request */ 110138430Sphk TAILQ_REMOVE(&nfslock_list, lm, lm_link); 111138430Sphk free(lm, M_NFSLOCK); 112138430Sphk } 113138430Sphk mtx_unlock(&nfslock_mtx); 114138430Sphk return (0); 115138430Sphk} 116138430Sphk 117138430Sphkstatic int 118138430Sphknfslock_read(struct cdev *dev, struct uio *uio, int ioflag) 119138430Sphk{ 120138430Sphk int error; 121138430Sphk struct __lock_msg *lm; 122138430Sphk 123138430Sphk if (uio->uio_resid != sizeof *lm) 124138430Sphk return (EOPNOTSUPP); 125138430Sphk lm = NULL; 126138430Sphk error = 0; 127138430Sphk mtx_lock(&nfslock_mtx); 128138430Sphk while (TAILQ_EMPTY(&nfslock_list)) { 129138430Sphk error = msleep(&nfslock_list, &nfslock_mtx, PSOCK | PCATCH, 130138430Sphk "nfslockd", 0); 131138430Sphk if (error) 132138430Sphk break; 133138430Sphk } 134138430Sphk if (!error) { 135138430Sphk lm = TAILQ_FIRST(&nfslock_list); 136138430Sphk TAILQ_REMOVE(&nfslock_list, lm, lm_link); 137138430Sphk } 138138430Sphk mtx_unlock(&nfslock_mtx); 139138430Sphk if (!error) { 140138430Sphk error = uiomove(lm, sizeof *lm, uio); 141138430Sphk free(lm, M_NFSLOCK); 142138430Sphk } 143138430Sphk return (error); 144138430Sphk} 145138430Sphk 146138430Sphkstatic int 147138430Sphknfslock_write(struct cdev *dev, struct uio *uio, int ioflag) 148138430Sphk{ 149138430Sphk struct lockd_ans la; 150138430Sphk int error; 151138430Sphk 152138430Sphk if (uio->uio_resid != sizeof la) 153138430Sphk return (EOPNOTSUPP); 154138430Sphk error = uiomove(&la, sizeof la, uio); 155138430Sphk if (!error) 156138430Sphk error = nfslockdans(curthread, &la); 157138430Sphk return (error); 158138430Sphk} 159138430Sphk 160138430Sphkstatic int 161138430Sphknfslock_send(struct __lock_msg *lm) 162138430Sphk{ 163138430Sphk struct __lock_msg *lm2; 164138430Sphk int error; 165138430Sphk 166138430Sphk error = 0; 167138430Sphk lm2 = malloc(sizeof *lm2, M_NFSLOCK, M_WAITOK); 168138430Sphk mtx_lock(&nfslock_mtx); 169138430Sphk if (nfslock_isopen) { 170138430Sphk memcpy(lm2, lm, sizeof *lm2); 171138430Sphk TAILQ_INSERT_TAIL(&nfslock_list, lm2, lm_link); 172138430Sphk wakeup(&nfslock_list); 173138430Sphk } else { 174138430Sphk error = EOPNOTSUPP; 175138430Sphk } 176138430Sphk mtx_unlock(&nfslock_mtx); 177138430Sphk if (error) 178138430Sphk free(lm2, M_NFSLOCK); 179138430Sphk return (error); 180138430Sphk} 181138430Sphk 182138430Sphkstatic struct cdevsw nfslock_cdevsw = { 183138430Sphk .d_version = D_VERSION, 184138430Sphk .d_open = nfslock_open, 185138430Sphk .d_close = nfslock_close, 186138430Sphk .d_read = nfslock_read, 187138430Sphk .d_write = nfslock_write, 188138430Sphk .d_name = "nfslock" 189138430Sphk}; 190138430Sphk 191138430Sphkstatic int 192138430Sphknfslock_modevent(module_t mod __unused, int type, void *data __unused) 193138430Sphk{ 194138430Sphk 195138430Sphk switch (type) { 196138430Sphk case MOD_LOAD: 197138430Sphk if (bootverbose) 198138430Sphk printf("nfslock: pseudo-device\n"); 199138430Sphk mtx_init(&nfslock_mtx, "nfslock", NULL, MTX_DEF); 200138430Sphk TAILQ_INIT(&nfslock_list); 201151695Sglebius nlminfo_release_p = nlminfo_release; 202138430Sphk nfslock_dev = make_dev(&nfslock_cdevsw, 0, 203138430Sphk UID_ROOT, GID_KMEM, 0600, _PATH_NFSLCKDEV); 204138430Sphk return (0); 205138430Sphk default: 206138430Sphk return (EOPNOTSUPP); 207138430Sphk } 208138430Sphk} 209138430Sphk 210138430SphkDEV_MODULE(nfslock, nfslock_modevent, NULL); 211138430SphkMODULE_VERSION(nfslock, 1); 212138430Sphk 213138430Sphk 214138430Sphk/* 21575631Salfred * XXX 21675631Salfred * We have to let the process know if the call succeeded. I'm using an extra 21783651Speter * field in the p_nlminfo field in the proc structure, as it is already for 21875631Salfred * lockd stuff. 21975631Salfred */ 22075631Salfred 22175631Salfred/* 22275631Salfred * nfs_advlock -- 22375631Salfred * NFS advisory byte-level locks. 22475631Salfred */ 22575631Salfredint 22683651Speternfs_dolock(struct vop_advlock_args *ap) 22775631Salfred{ 22875631Salfred LOCKD_MSG msg; 22983366Sjulian struct thread *td; 230138430Sphk struct vnode *vp; 231138430Sphk int error; 23275631Salfred struct flock *fl; 233138430Sphk int ioflg; 23483366Sjulian struct proc *p; 23575631Salfred 23683366Sjulian td = curthread; 23783366Sjulian p = td->td_proc; 23883366Sjulian 23975631Salfred vp = ap->a_vp; 24075631Salfred fl = ap->a_fl; 24175631Salfred 24275631Salfred /* 24375631Salfred * the NLM protocol doesn't allow the server to return an error 24482174Sache * on ranges, so we do it. 24575631Salfred */ 24682194Sache if (fl->l_whence != SEEK_END) { 24782213Sache if ((fl->l_whence != SEEK_CUR && fl->l_whence != SEEK_SET) || 24882204Sache fl->l_start < 0 || 24982204Sache (fl->l_len < 0 && 25082204Sache (fl->l_start == 0 || fl->l_start + fl->l_len < 0))) 25182194Sache return (EINVAL); 25282204Sache if (fl->l_len > 0 && 25382204Sache (fl->l_len - 1 > OFF_MAX - fl->l_start)) 25482194Sache return (EOVERFLOW); 25582194Sache } 25675631Salfred 25775631Salfred /* 25875631Salfred * Fill in the information structure. 25975631Salfred */ 26075631Salfred msg.lm_version = LOCKD_MSG_VERSION; 26175631Salfred msg.lm_msg_ident.pid = p->p_pid; 26275631Salfred /* 26375631Salfred * if there is no nfsowner table yet, allocate one. 26475631Salfred */ 26575631Salfred if (p->p_nlminfo == NULL) { 26675631Salfred MALLOC(p->p_nlminfo, struct nlminfo *, 267151695Sglebius sizeof(struct nlminfo), M_NLMINFO, M_WAITOK | M_ZERO); 26875631Salfred p->p_nlminfo->pid_start = p->p_stats->p_start; 269114434Sdes timevaladd(&p->p_nlminfo->pid_start, &boottime); 27075631Salfred } 27175631Salfred msg.lm_msg_ident.pid_start = p->p_nlminfo->pid_start; 27275631Salfred msg.lm_msg_ident.msg_seq = ++(p->p_nlminfo->msg_seq); 27375631Salfred 27475631Salfred msg.lm_fl = *fl; 27575631Salfred msg.lm_wait = ap->a_flags & F_WAIT; 27675631Salfred msg.lm_getlk = ap->a_op == F_GETLK; 277100134Salfred bcopy(VFSTONFS(vp->v_mount)->nm_nam, &msg.lm_addr, 278100134Salfred min(sizeof msg.lm_addr, VFSTONFS(vp->v_mount)->nm_nam->sa_len)); 27975631Salfred msg.lm_fh_len = NFS_ISV3(vp) ? VTONFS(vp)->n_fhsize : NFSX_V2FH; 28075631Salfred bcopy(VTONFS(vp)->n_fhp, msg.lm_fh, msg.lm_fh_len); 28175631Salfred msg.lm_nfsv3 = NFS_ISV3(vp); 282101947Salfred cru2x(td->td_ucred, &msg.lm_cred); 28375631Salfred 28475631Salfred for (;;) { 285138430Sphk error = nfslock_send(&msg); 286138430Sphk if (error) 287138430Sphk return (error); 28875631Salfred 289138430Sphk /* Unlocks succeed immediately. */ 29075631Salfred if (fl->l_type == F_UNLCK) 291138430Sphk return (error); 29275631Salfred 29375631Salfred /* 29475631Salfred * retry after 20 seconds if we haven't gotten a responce yet. 29575631Salfred * This number was picked out of thin air... but is longer 29675631Salfred * then even a reasonably loaded system should take (at least 29783651Speter * on a local network). XXX Probably should use a back-off 29875631Salfred * scheme. 299116185Srwatson * 300116185Srwatson * XXX: No PCATCH here since we currently have no useful 301116185Srwatson * way to signal to the userland rpc.lockd that the request 302116185Srwatson * has been aborted. Once the rpc.lockd implementation 303116185Srwatson * can handle aborts, and we report them properly, 304116185Srwatson * PCATCH can be put back. In the mean time, if we did 305116185Srwatson * permit aborting, the lock attempt would "get lost" 306116185Srwatson * and the lock would get stuck in the locked state. 30775631Salfred */ 308115415Srwatson error = tsleep(p->p_nlminfo, PUSER, "lockd", 20*hz); 309107104Salfred if (error != 0) { 31075631Salfred if (error == EWOULDBLOCK) { 31175631Salfred /* 31275631Salfred * We timed out, so we rewrite the request 31375631Salfred * to the fifo, but only if it isn't already 31475631Salfred * full. 31575631Salfred */ 31675631Salfred ioflg |= IO_NDELAY; 31775631Salfred continue; 31875631Salfred } 31975631Salfred 32075631Salfred break; 32175631Salfred } 32275631Salfred 32375631Salfred if (msg.lm_getlk && p->p_nlminfo->retcode == 0) { 32475631Salfred if (p->p_nlminfo->set_getlk_pid) { 32575631Salfred fl->l_pid = p->p_nlminfo->getlk_pid; 32675631Salfred } else { 32775631Salfred fl->l_type = F_UNLCK; 32875631Salfred } 32975631Salfred } 33075631Salfred error = p->p_nlminfo->retcode; 33175631Salfred break; 33275631Salfred } 33375631Salfred 334138430Sphk return (error); 33575631Salfred} 33675631Salfred 33775631Salfred/* 33875631Salfred * nfslockdans -- 33975631Salfred * NFS advisory byte-level locks answer from the lock daemon. 34075631Salfred */ 341138430Sphkstatic int 34286363Srwatsonnfslockdans(struct thread *td, struct lockd_ans *ansp) 34375631Salfred{ 34486363Srwatson struct proc *targetp; 34575631Salfred int error; 34675631Salfred 34775631Salfred /* Let root, or someone who once was root (lockd generally 34883651Speter * switches to the daemon uid once it is done setting up) make 34977183Srwatson * this call. 35077183Srwatson * 35177183Srwatson * XXX This authorization check is probably not right. 35275631Salfred */ 35393593Sjhb if ((error = suser(td)) != 0 && 35491406Sjhb td->td_ucred->cr_svuid != 0) 35575631Salfred return (error); 35675631Salfred 35775631Salfred /* the version should match, or we're out of sync */ 35875631Salfred if (ansp->la_vers != LOCKD_ANS_VERSION) 35975631Salfred return (EINVAL); 36075631Salfred 36175631Salfred /* Find the process, set its return errno and wake it up. */ 36286363Srwatson if ((targetp = pfind(ansp->la_msg_ident.pid)) == NULL) 36375631Salfred return (ESRCH); 36475631Salfred 36583651Speter /* verify the pid hasn't been reused (if we can), and it isn't waiting 36675631Salfred * for an answer from a more recent request. We return an EPIPE if 36775631Salfred * the match fails, because we've already used ESRCH above, and this 36875631Salfred * is sort of like writing on a pipe after the reader has closed it. 36975631Salfred */ 37086363Srwatson if (targetp->p_nlminfo == NULL || 37175631Salfred ((ansp->la_msg_ident.msg_seq != -1) && 37286363Srwatson (timevalcmp(&targetp->p_nlminfo->pid_start, 37375631Salfred &ansp->la_msg_ident.pid_start, !=) || 37486363Srwatson targetp->p_nlminfo->msg_seq != ansp->la_msg_ident.msg_seq))) { 37586363Srwatson PROC_UNLOCK(targetp); 37675631Salfred return (EPIPE); 37777563Sjake } 37875631Salfred 37986363Srwatson targetp->p_nlminfo->retcode = ansp->la_errno; 38086363Srwatson targetp->p_nlminfo->set_getlk_pid = ansp->la_set_getlk_pid; 38186363Srwatson targetp->p_nlminfo->getlk_pid = ansp->la_getlk_pid; 38275631Salfred 383107104Salfred wakeup(targetp->p_nlminfo); 38475631Salfred 38586363Srwatson PROC_UNLOCK(targetp); 38675631Salfred return (0); 38775631Salfred} 388138430Sphk 389151695Sglebius/* 390151695Sglebius * Free nlminfo attached to process. 391151695Sglebius */ 392151695Sglebiusvoid 393151695Sglebiusnlminfo_release(struct proc *p) 394151695Sglebius{ 395151695Sglebius free(p->p_nlminfo, M_NLMINFO); 396151695Sglebius p->p_nlminfo = NULL; 397151695Sglebius} 398