nfs_lock.c revision 100134
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 100134 2002-07-15 19:40:23Z alfred $"); 3383651Speter 3475631Salfred#include <sys/param.h> 3575631Salfred#include <sys/systm.h> 3675631Salfred#include <sys/fcntl.h> 3776166Smarkm#include <sys/kernel.h> /* for hz */ 3876166Smarkm#include <sys/lock.h> 3975631Salfred#include <sys/malloc.h> 4076166Smarkm#include <sys/lockf.h> /* for hz */ /* Must come after sys/malloc.h */ 4175631Salfred#include <sys/mbuf.h> 4275631Salfred#include <sys/mount.h> 4375631Salfred#include <sys/namei.h> 4475631Salfred#include <sys/proc.h> 4576166Smarkm#include <sys/resourcevar.h> 4675631Salfred#include <sys/socket.h> 4776166Smarkm#include <sys/socket.h> 4875631Salfred#include <sys/unistd.h> 4975631Salfred#include <sys/vnode.h> 5075631Salfred 5182190Sache#include <machine/limits.h> 5282190Sache 5375631Salfred#include <net/if.h> 5475631Salfred 5575631Salfred#include <nfs/rpcv2.h> 5675631Salfred#include <nfs/nfsproto.h> 5783651Speter#include <nfsclient/nfs.h> 5883651Speter#include <nfsclient/nfsmount.h> 5983651Speter#include <nfsclient/nfsnode.h> 6083651Speter#include <nfsclient/nfs_lock.h> 6183651Speter#include <nfsclient/nlminfo.h> 6275631Salfred 6375631Salfred#define NFSOWNER_1ST_LEVEL_START 1 /* initial entries */ 6475631Salfred#define NFSOWNER_2ND_LEVEL 256 /* some power of 2 */ 6575631Salfred 6675631Salfred#define NFSOWNER(tbl, i) \ 6775631Salfred (tbl)[(i) / NFSOWNER_2ND_LEVEL][(i) % NFSOWNER_2ND_LEVEL] 6875631Salfred 6975631Salfred/* 7075631Salfred * XXX 7175631Salfred * We have to let the process know if the call succeeded. I'm using an extra 7283651Speter * field in the p_nlminfo field in the proc structure, as it is already for 7375631Salfred * lockd stuff. 7475631Salfred */ 7575631Salfred 7675631Salfred/* 7775631Salfred * nfs_advlock -- 7875631Salfred * NFS advisory byte-level locks. 7975631Salfred */ 8075631Salfredint 8183651Speternfs_dolock(struct vop_advlock_args *ap) 8275631Salfred{ 8375631Salfred LOCKD_MSG msg; 8475631Salfred struct nameidata nd; 8583366Sjulian struct thread *td; 8675631Salfred struct vnode *vp, *wvp; 8775631Salfred int error, error1; 8875631Salfred struct flock *fl; 8975631Salfred int fmode, ioflg; 9083366Sjulian struct proc *p; 9175631Salfred 9283366Sjulian td = curthread; 9383366Sjulian p = td->td_proc; 9483366Sjulian 9575631Salfred vp = ap->a_vp; 9675631Salfred fl = ap->a_fl; 9775631Salfred 9875631Salfred /* 9975631Salfred * the NLM protocol doesn't allow the server to return an error 10082174Sache * on ranges, so we do it. 10175631Salfred */ 10282194Sache if (fl->l_whence != SEEK_END) { 10382213Sache if ((fl->l_whence != SEEK_CUR && fl->l_whence != SEEK_SET) || 10482204Sache fl->l_start < 0 || 10582204Sache (fl->l_len < 0 && 10682204Sache (fl->l_start == 0 || fl->l_start + fl->l_len < 0))) 10782194Sache return (EINVAL); 10882204Sache if (fl->l_len > 0 && 10982204Sache (fl->l_len - 1 > OFF_MAX - fl->l_start)) 11082194Sache return (EOVERFLOW); 11182194Sache } 11275631Salfred 11375631Salfred /* 11475631Salfred * Fill in the information structure. 11575631Salfred */ 11675631Salfred msg.lm_version = LOCKD_MSG_VERSION; 11775631Salfred msg.lm_msg_ident.pid = p->p_pid; 11875631Salfred /* 11975631Salfred * if there is no nfsowner table yet, allocate one. 12075631Salfred */ 12175631Salfred if (p->p_nlminfo == NULL) { 12275631Salfred MALLOC(p->p_nlminfo, struct nlminfo *, 12375631Salfred sizeof(struct nlminfo), M_LOCKF, M_WAITOK | M_ZERO); 12475631Salfred p->p_nlminfo->pid_start = p->p_stats->p_start; 12575631Salfred } 12675631Salfred msg.lm_msg_ident.pid_start = p->p_nlminfo->pid_start; 12775631Salfred msg.lm_msg_ident.msg_seq = ++(p->p_nlminfo->msg_seq); 12875631Salfred 12975631Salfred msg.lm_fl = *fl; 13075631Salfred msg.lm_wait = ap->a_flags & F_WAIT; 13175631Salfred msg.lm_getlk = ap->a_op == F_GETLK; 13275631Salfred /* 13385398Srwatson * XXX: the lm_cred assignment below directly exports a ucred 13485398Srwatson * structure to userland. This is probably wrong, and should at 13585398Srwatson * least be xucred. 13675631Salfred */ 137100134Salfred bcopy(VFSTONFS(vp->v_mount)->nm_nam, &msg.lm_addr, 138100134Salfred min(sizeof msg.lm_addr, VFSTONFS(vp->v_mount)->nm_nam->sa_len)); 13975631Salfred msg.lm_fh_len = NFS_ISV3(vp) ? VTONFS(vp)->n_fhsize : NFSX_V2FH; 14075631Salfred bcopy(VTONFS(vp)->n_fhp, msg.lm_fh, msg.lm_fh_len); 14175631Salfred msg.lm_nfsv3 = NFS_ISV3(vp); 14291406Sjhb msg.lm_cred = *(td->td_ucred); 14375631Salfred 14475631Salfred /* 14575631Salfred * Open the lock fifo. If for any reason we don't find the fifo, it 14675631Salfred * means that the lock daemon isn't running. Translate any missing 14775631Salfred * file error message for the user, otherwise the application will 14875631Salfred * complain that the user's file is missing, which isn't the case. 14975631Salfred * Note that we use proc0's cred, so the fifo is opened as root. 15085370Srwatson * 15185370Srwatson * XXX: Note that this behavior is relative to the root directory 15285370Srwatson * of the current process, and this may result in a variety of 15385370Srwatson * {functional, security} problems in chroot() environments. 15475631Salfred */ 15583366Sjulian NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, _PATH_LCKFIFO, td); 15675631Salfred 15775631Salfred fmode = FFLAGS(O_WRONLY); 15891420Sjhb error = vn_open_cred(&nd, &fmode, 0, thread0.td_ucred); 15975631Salfred if (error != 0) { 16075631Salfred return (error == ENOENT ? EOPNOTSUPP : error); 16175631Salfred } 16275631Salfred wvp = nd.ni_vp; 16383366Sjulian VOP_UNLOCK(wvp, 0, td); /* vn_open leaves it locked */ 16475631Salfred 16575631Salfred 16675631Salfred ioflg = IO_UNIT; 16775631Salfred for (;;) { 16891420Sjhb VOP_LEASE(wvp, td, thread0.td_ucred, LEASE_WRITE); 16975631Salfred 17075631Salfred error = vn_rdwr(UIO_WRITE, wvp, (caddr_t)&msg, sizeof(msg), 0, 17191420Sjhb UIO_SYSSPACE, ioflg, thread0.td_ucred, NULL, td); 17275631Salfred 17375631Salfred if (error && (((ioflg & IO_NDELAY) == 0) || error != EAGAIN)) { 17475631Salfred break; 17575631Salfred } 17675631Salfred /* 17775631Salfred * If we're locking a file, wait for an answer. Unlocks succeed 17875631Salfred * immediately. 17975631Salfred */ 18075631Salfred if (fl->l_type == F_UNLCK) 18175631Salfred /* 18275631Salfred * XXX this isn't exactly correct. The client side 18375631Salfred * needs to continue sending it's unlock until 18475631Salfred * it gets a responce back. 18575631Salfred */ 18675631Salfred break; 18775631Salfred 18875631Salfred /* 18975631Salfred * retry after 20 seconds if we haven't gotten a responce yet. 19075631Salfred * This number was picked out of thin air... but is longer 19175631Salfred * then even a reasonably loaded system should take (at least 19283651Speter * on a local network). XXX Probably should use a back-off 19375631Salfred * scheme. 19475631Salfred */ 19583651Speter if ((error = tsleep((void *)p->p_nlminfo, 19675631Salfred PCATCH | PUSER, "lockd", 20*hz)) != 0) { 19775631Salfred if (error == EWOULDBLOCK) { 19875631Salfred /* 19975631Salfred * We timed out, so we rewrite the request 20075631Salfred * to the fifo, but only if it isn't already 20175631Salfred * full. 20275631Salfred */ 20375631Salfred ioflg |= IO_NDELAY; 20475631Salfred continue; 20575631Salfred } 20675631Salfred 20775631Salfred break; 20875631Salfred } 20975631Salfred 21075631Salfred if (msg.lm_getlk && p->p_nlminfo->retcode == 0) { 21175631Salfred if (p->p_nlminfo->set_getlk_pid) { 21275631Salfred fl->l_pid = p->p_nlminfo->getlk_pid; 21375631Salfred } else { 21475631Salfred fl->l_type = F_UNLCK; 21575631Salfred } 21675631Salfred } 21775631Salfred error = p->p_nlminfo->retcode; 21875631Salfred break; 21975631Salfred } 22075631Salfred 22191420Sjhb if ((error1 = vn_close(wvp, FWRITE, thread0.td_ucred, td)) && error == 0) 22275631Salfred return (error1); 22375631Salfred 22475631Salfred return (error); 22575631Salfred} 22675631Salfred 22775631Salfred/* 22875631Salfred * nfslockdans -- 22975631Salfred * NFS advisory byte-level locks answer from the lock daemon. 23075631Salfred */ 23175631Salfredint 23286363Srwatsonnfslockdans(struct thread *td, struct lockd_ans *ansp) 23375631Salfred{ 23486363Srwatson struct proc *targetp; 23575631Salfred int error; 23675631Salfred 23775631Salfred /* Let root, or someone who once was root (lockd generally 23883651Speter * switches to the daemon uid once it is done setting up) make 23977183Srwatson * this call. 24077183Srwatson * 24177183Srwatson * XXX This authorization check is probably not right. 24275631Salfred */ 24393593Sjhb if ((error = suser(td)) != 0 && 24491406Sjhb td->td_ucred->cr_svuid != 0) 24575631Salfred return (error); 24675631Salfred 24775631Salfred /* the version should match, or we're out of sync */ 24875631Salfred if (ansp->la_vers != LOCKD_ANS_VERSION) 24975631Salfred return (EINVAL); 25075631Salfred 25175631Salfred /* Find the process, set its return errno and wake it up. */ 25286363Srwatson if ((targetp = pfind(ansp->la_msg_ident.pid)) == NULL) 25375631Salfred return (ESRCH); 25475631Salfred 25583651Speter /* verify the pid hasn't been reused (if we can), and it isn't waiting 25675631Salfred * for an answer from a more recent request. We return an EPIPE if 25775631Salfred * the match fails, because we've already used ESRCH above, and this 25875631Salfred * is sort of like writing on a pipe after the reader has closed it. 25975631Salfred */ 26086363Srwatson if (targetp->p_nlminfo == NULL || 26175631Salfred ((ansp->la_msg_ident.msg_seq != -1) && 26286363Srwatson (timevalcmp(&targetp->p_nlminfo->pid_start, 26375631Salfred &ansp->la_msg_ident.pid_start, !=) || 26486363Srwatson targetp->p_nlminfo->msg_seq != ansp->la_msg_ident.msg_seq))) { 26586363Srwatson PROC_UNLOCK(targetp); 26675631Salfred return (EPIPE); 26777563Sjake } 26875631Salfred 26986363Srwatson targetp->p_nlminfo->retcode = ansp->la_errno; 27086363Srwatson targetp->p_nlminfo->set_getlk_pid = ansp->la_set_getlk_pid; 27186363Srwatson targetp->p_nlminfo->getlk_pid = ansp->la_getlk_pid; 27275631Salfred 27386363Srwatson (void)wakeup((void *)targetp->p_nlminfo); 27475631Salfred 27586363Srwatson PROC_UNLOCK(targetp); 27675631Salfred return (0); 27775631Salfred} 278