/*- * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Berkeley Software Design Inc's name may not be used to endorse or * promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from BSDI nfs_lock.c,v 2.4 1998/12/14 23:49:56 jch Exp */ #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); #include <sys/param.h> #include <sys/systm.h> #include <sys/conf.h> #include <sys/fcntl.h> #include <sys/kernel.h> /* for hz */ #include <sys/limits.h> #include <sys/lock.h> #include <sys/malloc.h> #include <sys/lockf.h> /* for hz */ /* Must come after sys/malloc.h */ #include <sys/mbuf.h> #include <sys/mount.h> #include <sys/namei.h> #include <sys/proc.h> #include <sys/resourcevar.h> #include <sys/socket.h> #include <sys/socket.h> #include <sys/unistd.h> #include <sys/vnode.h> #include <net/if.h> #include <rpc/rpcclnt.h> #include <nfs/rpcv2.h> #include <nfs/nfsproto.h> #include <nfsclient/nfs.h> #include <nfsclient/nfsmount.h> #include <nfsclient/nfsnode.h> #include <nfsclient/nfs_lock.h> #include <nfsclient/nlminfo.h> extern void (*nlminfo_release_p)(struct proc *p); MALLOC_DEFINE(M_NFSLOCK, "NFS lock", "NFS lock request"); MALLOC_DEFINE(M_NLMINFO, "nlminfo", "NFS lock process structure"); static int nfslockdans(struct thread *td, struct lockd_ans *ansp); static void nlminfo_release(struct proc *p); /* * -------------------------------------------------------------------- * A miniature device driver which the userland uses to talk to us. * */ static struct cdev *nfslock_dev; static struct mtx nfslock_mtx; static int nfslock_isopen; static TAILQ_HEAD(,__lock_msg) nfslock_list; static int nfslock_open(struct cdev *dev, int oflags, int devtype, struct thread *td) { int error; mtx_lock(&nfslock_mtx); if (!nfslock_isopen) { error = 0; nfslock_isopen = 1; } else { error = EOPNOTSUPP; } mtx_unlock(&nfslock_mtx); return (error); } static int nfslock_close(struct cdev *dev, int fflag, int devtype, struct thread *td) { struct __lock_msg *lm; mtx_lock(&nfslock_mtx); nfslock_isopen = 0; while (!TAILQ_EMPTY(&nfslock_list)) { lm = TAILQ_FIRST(&nfslock_list); /* XXX: answer request */ TAILQ_REMOVE(&nfslock_list, lm, lm_link); free(lm, M_NFSLOCK); } mtx_unlock(&nfslock_mtx); return (0); } static int nfslock_read(struct cdev *dev, struct uio *uio, int ioflag) { int error; struct __lock_msg *lm; if (uio->uio_resid != sizeof *lm) return (EOPNOTSUPP); lm = NULL; error = 0; mtx_lock(&nfslock_mtx); while (TAILQ_EMPTY(&nfslock_list)) { error = msleep(&nfslock_list, &nfslock_mtx, PSOCK | PCATCH, "nfslockd", 0); if (error) break; } if (!error) { lm = TAILQ_FIRST(&nfslock_list); TAILQ_REMOVE(&nfslock_list, lm, lm_link); } mtx_unlock(&nfslock_mtx); if (!error) { error = uiomove(lm, sizeof *lm, uio); free(lm, M_NFSLOCK); } return (error); } static int nfslock_write(struct cdev *dev, struct uio *uio, int ioflag) { struct lockd_ans la; int error; if (uio->uio_resid != sizeof la) return (EOPNOTSUPP); error = uiomove(&la, sizeof la, uio); if (!error) error = nfslockdans(curthread, &la); return (error); } static int nfslock_send(struct __lock_msg *lm) { struct __lock_msg *lm2; int error; error = 0; lm2 = malloc(sizeof *lm2, M_NFSLOCK, M_WAITOK); mtx_lock(&nfslock_mtx); if (nfslock_isopen) { memcpy(lm2, lm, sizeof *lm2); TAILQ_INSERT_TAIL(&nfslock_list, lm2, lm_link); wakeup(&nfslock_list); } else { error = EOPNOTSUPP; } mtx_unlock(&nfslock_mtx); if (error) free(lm2, M_NFSLOCK); return (error); } static struct cdevsw nfslock_cdevsw = { .d_version = D_VERSION, .d_open = nfslock_open, .d_close = nfslock_close, .d_read = nfslock_read, .d_write = nfslock_write, .d_name = "nfslock" }; static int nfslock_modevent(module_t mod __unused, int type, void *data __unused) { switch (type) { case MOD_LOAD: if (bootverbose) printf("nfslock: pseudo-device\n"); mtx_init(&nfslock_mtx, "nfslock", NULL, MTX_DEF); TAILQ_INIT(&nfslock_list); nlminfo_release_p = nlminfo_release; nfslock_dev = make_dev(&nfslock_cdevsw, 0, UID_ROOT, GID_KMEM, 0600, _PATH_NFSLCKDEV); return (0); default: return (EOPNOTSUPP); } } DEV_MODULE(nfslock, nfslock_modevent, NULL); MODULE_VERSION(nfslock, 1); /* * XXX * We have to let the process know if the call succeeded. I'm using an extra * field in the p_nlminfo field in the proc structure, as it is already for * lockd stuff. */ /* * nfs_advlock -- * NFS advisory byte-level locks. */ int nfs_dolock(struct vop_advlock_args *ap) { LOCKD_MSG msg; struct thread *td; struct vnode *vp; int error; struct flock *fl; int ioflg; struct proc *p; td = curthread; p = td->td_proc; vp = ap->a_vp; fl = ap->a_fl; /* * the NLM protocol doesn't allow the server to return an error * on ranges, so we do it. */ if (fl->l_whence != SEEK_END) { if ((fl->l_whence != SEEK_CUR && fl->l_whence != SEEK_SET) || fl->l_start < 0 || (fl->l_len < 0 && (fl->l_start == 0 || fl->l_start + fl->l_len < 0))) return (EINVAL); if (fl->l_len > 0 && (fl->l_len - 1 > OFF_MAX - fl->l_start)) return (EOVERFLOW); } /* * Fill in the information structure. */ msg.lm_version = LOCKD_MSG_VERSION; msg.lm_msg_ident.pid = p->p_pid; /* * if there is no nfsowner table yet, allocate one. */ if (p->p_nlminfo == NULL) { MALLOC(p->p_nlminfo, struct nlminfo *, sizeof(struct nlminfo), M_NLMINFO, M_WAITOK | M_ZERO); p->p_nlminfo->pid_start = p->p_stats->p_start; timevaladd(&p->p_nlminfo->pid_start, &boottime); } msg.lm_msg_ident.pid_start = p->p_nlminfo->pid_start; msg.lm_msg_ident.msg_seq = ++(p->p_nlminfo->msg_seq); msg.lm_fl = *fl; msg.lm_wait = ap->a_flags & F_WAIT; msg.lm_getlk = ap->a_op == F_GETLK; bcopy(VFSTONFS(vp->v_mount)->nm_nam, &msg.lm_addr, min(sizeof msg.lm_addr, VFSTONFS(vp->v_mount)->nm_nam->sa_len)); msg.lm_fh_len = NFS_ISV3(vp) ? VTONFS(vp)->n_fhsize : NFSX_V2FH; bcopy(VTONFS(vp)->n_fhp, msg.lm_fh, msg.lm_fh_len); msg.lm_nfsv3 = NFS_ISV3(vp); cru2x(td->td_ucred, &msg.lm_cred); for (;;) { error = nfslock_send(&msg); if (error) return (error); /* Unlocks succeed immediately. */ if (fl->l_type == F_UNLCK) return (error); /* * retry after 20 seconds if we haven't gotten a responce yet. * This number was picked out of thin air... but is longer * then even a reasonably loaded system should take (at least * on a local network). XXX Probably should use a back-off * scheme. * * XXX: No PCATCH here since we currently have no useful * way to signal to the userland rpc.lockd that the request * has been aborted. Once the rpc.lockd implementation * can handle aborts, and we report them properly, * PCATCH can be put back. In the mean time, if we did * permit aborting, the lock attempt would "get lost" * and the lock would get stuck in the locked state. */ error = tsleep(p->p_nlminfo, PUSER, "lockd", 20*hz); if (error != 0) { if (error == EWOULDBLOCK) { /* * We timed out, so we rewrite the request * to the fifo, but only if it isn't already * full. */ ioflg |= IO_NDELAY; continue; } break; } if (msg.lm_getlk && p->p_nlminfo->retcode == 0) { if (p->p_nlminfo->set_getlk_pid) { fl->l_pid = p->p_nlminfo->getlk_pid; } else { fl->l_type = F_UNLCK; } } error = p->p_nlminfo->retcode; break; } return (error); } /* * nfslockdans -- * NFS advisory byte-level locks answer from the lock daemon. */ static int nfslockdans(struct thread *td, struct lockd_ans *ansp) { struct proc *targetp; int error; /* Let root, or someone who once was root (lockd generally * switches to the daemon uid once it is done setting up) make * this call. * * XXX This authorization check is probably not right. */ if ((error = suser(td)) != 0 && td->td_ucred->cr_svuid != 0) return (error); /* the version should match, or we're out of sync */ if (ansp->la_vers != LOCKD_ANS_VERSION) return (EINVAL); /* Find the process, set its return errno and wake it up. */ if ((targetp = pfind(ansp->la_msg_ident.pid)) == NULL) return (ESRCH); /* verify the pid hasn't been reused (if we can), and it isn't waiting * for an answer from a more recent request. We return an EPIPE if * the match fails, because we've already used ESRCH above, and this * is sort of like writing on a pipe after the reader has closed it. */ if (targetp->p_nlminfo == NULL || ((ansp->la_msg_ident.msg_seq != -1) && (timevalcmp(&targetp->p_nlminfo->pid_start, &ansp->la_msg_ident.pid_start, !=) || targetp->p_nlminfo->msg_seq != ansp->la_msg_ident.msg_seq))) { PROC_UNLOCK(targetp); return (EPIPE); } targetp->p_nlminfo->retcode = ansp->la_errno; targetp->p_nlminfo->set_getlk_pid = ansp->la_set_getlk_pid; targetp->p_nlminfo->getlk_pid = ansp->la_getlk_pid; wakeup(targetp->p_nlminfo); PROC_UNLOCK(targetp); return (0); } /* * Free nlminfo attached to process. */ void nlminfo_release(struct proc *p) { free(p->p_nlminfo, M_NLMINFO); p->p_nlminfo = NULL; }