diff options
Diffstat (limited to 'sys/nfs/nfs_lock.c')
| -rw-r--r-- | sys/nfs/nfs_lock.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/sys/nfs/nfs_lock.c b/sys/nfs/nfs_lock.c new file mode 100644 index 0000000..aaac361 --- /dev/null +++ b/sys/nfs/nfs_lock.c @@ -0,0 +1,269 @@ +/*- + * 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 + * $FreeBSD$ + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/fcntl.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/mount.h> +#include <sys/namei.h> +#include <sys/proc.h> +#include <sys/socket.h> +#include <sys/unistd.h> +#include <sys/vnode.h> +#include <sys/resourcevar.h> +#include <sys/kernel.h> /* for hz */ +#include <sys/lockf.h> /* for hz */ + +#include <net/if.h> + +#include <nfs/rpcv2.h> +#include <nfs/nfsproto.h> +#include <nfs/nfs.h> +#include <nfs/nfsmount.h> +#include <nfs/nfsnode.h> +#include <nfs/nfs_lock.h> +#include <nfs/nlminfo.h> + +#define NFSOWNER_1ST_LEVEL_START 1 /* initial entries */ +#define NFSOWNER_2ND_LEVEL 256 /* some power of 2 */ + +#define NFSOWNER(tbl, i) \ + (tbl)[(i) / NFSOWNER_2ND_LEVEL][(i) % NFSOWNER_2ND_LEVEL] + +/* + * 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(ap) + struct vop_advlock_args /* { + struct vnode *a_vp; + caddr_t a_id; + int a_op; + struct flock *a_fl; + int a_flags; + } */ *ap; +{ + LOCKD_MSG msg; + struct nameidata nd; + struct proc *p; + uid_t saved_uid; + struct vnode *vp, *wvp; + int error, error1; + struct flock *fl; + int fmode, ioflg; + + p = curproc; + 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. Note that we should be returning + * EOVERFLOW in some cases, but we don't have it. + */ + if (fl->l_start < 0 || fl->l_len < 0 || + ((fl->l_len != 0 && + (fl->l_start + fl->l_len - 1) < 0))) + return (EINVAL); + + /* + * 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_LOCKF, M_WAITOK | M_ZERO); + p->p_nlminfo->pid_start = p->p_stats->p_start; + } + 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; + /* + * XXX -- I think this is wrong for anything other AF_INET. + */ + msg.lm_addr = *(VFSTONFS(vp->v_mount)->nm_nam); + 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); + msg.lm_cred = *(p->p_ucred); + + /* + * Open the lock fifo. If for any reason we don't find the fifo, it + * means that the lock daemon isn't running. Translate any missing + * file error message for the user, otherwise the application will + * complain that the user's file is missing, which isn't the case. + * Note that we use proc0's cred, so the fifo is opened as root. + */ + NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, _PATH_LCKFIFO, p); + + /* + * XXX Hack to temporarily allow this process (regardless of it's creds) + * to open the fifo we need to write to. vn_open() really should + * take a ucred (and once it does, this code should be fixed to use + * proc0's ucred. + */ + saved_uid = p->p_ucred->cr_uid; + p->p_ucred->cr_uid = 0; /* temporarly run the vn_open as root */ + + fmode = FFLAGS(O_WRONLY); + error = vn_open(&nd, &fmode, 0); + p->p_ucred->cr_uid = saved_uid; + if (error != 0) { + return (error == ENOENT ? EOPNOTSUPP : error); + } + wvp = nd.ni_vp; + VOP_UNLOCK(wvp, 0, p); /* vn_open leaves it locked */ + + + ioflg = IO_UNIT; + for (;;) { + VOP_LEASE(wvp, p, proc0.p_ucred, LEASE_WRITE); + + error = vn_rdwr(UIO_WRITE, wvp, (caddr_t)&msg, sizeof(msg), 0, + UIO_SYSSPACE, ioflg, proc0.p_ucred, NULL, p); + + if (error && (((ioflg & IO_NDELAY) == 0) || error != EAGAIN)) { + break; + } + /* + * If we're locking a file, wait for an answer. Unlocks succeed + * immediately. + */ + if (fl->l_type == F_UNLCK) + /* + * XXX this isn't exactly correct. The client side + * needs to continue sending it's unlock until + * it gets a responce back. + */ + break; + + /* + * 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. + */ + if ((error = tsleep((void *)p->p_nlminfo, + PCATCH | PUSER, "lockd", 20*hz)) != 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; + } + + if ((error1 = vn_close(wvp, FWRITE, proc0.p_ucred, p)) && error == 0) + return (error1); + + return (error); +} + +/* + * nfslockdans -- + * NFS advisory byte-level locks answer from the lock daemon. + */ +int +nfslockdans(p, ansp) + struct proc *p; + struct lockd_ans *ansp; +{ + 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 + */ + if ((error = suser(p)) != 0 && p->p_cred->p_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 ((p = 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 (p->p_nlminfo == NULL || + ((ansp->la_msg_ident.msg_seq != -1) && + (timevalcmp(&p->p_nlminfo->pid_start, + &ansp->la_msg_ident.pid_start, !=) || + p->p_nlminfo->msg_seq != ansp->la_msg_ident.msg_seq))) + return (EPIPE); + + p->p_nlminfo->retcode = ansp->la_errno; + p->p_nlminfo->set_getlk_pid = ansp->la_set_getlk_pid; + p->p_nlminfo->getlk_pid = ansp->la_getlk_pid; + + (void)wakeup((void *)p->p_nlminfo); + + return (0); +} |
