diff options
author | Rick Macklem <rmacklem@FreeBSD.org> | 2010-07-24 22:11:11 +0000 |
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committer | Rick Macklem <rmacklem@FreeBSD.org> | 2010-07-24 22:11:11 +0000 |
commit | f92bbff2481ab999e7fec098d7c232779df7aa73 (patch) | |
tree | 4eec6454349918ebb035552eba42b0ef1fd7eaa6 /sys/nfs/nfs_lock.c | |
parent | 7f5b7f232394ad7a4e815fe755279eece957d22e (diff) | |
download | src-f92bbff2481ab999e7fec098d7c232779df7aa73.tar.gz src-f92bbff2481ab999e7fec098d7c232779df7aa73.zip |
Move sys/nfsclient/nfs_lock.c into sys/nfs and build it as a separate
module that can be used by both the regular and experimental nfs
clients. This fixes the problem reported by jh@ where /dev/nfslock
would be registered twice when both nfs clients were used.
I also defined the size of the lm_fh field to be the correct value,
as it should be the maximum size of an NFSv3 file handle.
Reviewed by: jh
MFC after: 2 weeks
Notes
Notes:
svn path=/head/; revision=210455
Diffstat (limited to 'sys/nfs/nfs_lock.c')
-rw-r--r-- | sys/nfs/nfs_lock.c | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/sys/nfs/nfs_lock.c b/sys/nfs/nfs_lock.c new file mode 100644 index 000000000000..89ad65422433 --- /dev/null +++ b/sys/nfs/nfs_lock.c @@ -0,0 +1,396 @@ +/*- + * 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/priv.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 <nfs/nfsproto.h> +#include <nfs/nfs_lock.h> +#include <nfsclient/nfs.h> +#include <nfsclient/nfsmount.h> +#include <nfsclient/nfsnode.h> +#include <nfsclient/nlminfo.h> + +extern void (*nlminfo_release_p)(struct proc *p); + +MALLOC_DEFINE(M_NFSLOCK, "nfsclient_lock", "NFS lock request"); +MALLOC_DEFINE(M_NLMINFO, "nfsclient_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; + + error = priv_check(td, PRIV_NFS_LOCKD); + if (error) + return (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. + * + * The vnode shall be (shared) locked on the entry, it is + * unconditionally unlocked after. + */ +int +nfs_dolock(struct vop_advlock_args *ap) +{ + LOCKD_MSG msg; + struct thread *td; + struct vnode *vp; + int error; + struct flock *fl; + struct proc *p; + + td = curthread; + p = td->td_proc; + + vp = ap->a_vp; + fl = ap->a_fl; + + ASSERT_VOP_LOCKED(vp, "nfs_dolock"); + + 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); + VOP_UNLOCK(vp, 0); + + /* + * 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; + + mtx_lock(&Giant); + /* + * if there is no nfsowner table yet, allocate one. + */ + if (p->p_nlminfo == NULL) { + p->p_nlminfo = malloc(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; + cru2x(td->td_ucred, &msg.lm_cred); + + for (;;) { + error = nfslock_send(&msg); + if (error) + goto out; + + /* Unlocks succeed immediately. */ + if (fl->l_type == F_UNLCK) + goto out; + + /* + * Retry after 20 seconds if we haven't gotten a response 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. + */ + continue; + } + + break; + } + + if (msg.lm_getlk && p->p_nlminfo->retcode == 0) { + if (p->p_nlminfo->set_getlk_pid) { + fl->l_sysid = 0; /* XXX */ + fl->l_pid = p->p_nlminfo->getlk_pid; + } else { + fl->l_type = F_UNLCK; + } + } + error = p->p_nlminfo->retcode; + break; + } + out: + mtx_unlock(&Giant); + 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; + + /* 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; +} |