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-rw-r--r--sys/kern/kern_lockf.c846
1 files changed, 846 insertions, 0 deletions
diff --git a/sys/kern/kern_lockf.c b/sys/kern/kern_lockf.c
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--- /dev/null
+++ b/sys/kern/kern_lockf.c
@@ -0,0 +1,846 @@
+/*
+ * Copyright (c) 1982, 1986, 1989, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Scooter Morris at Genentech Inc.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 THE REGENTS OR CONTRIBUTORS 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.
+ *
+ * @(#)ufs_lockf.c 8.3 (Berkeley) 1/6/94
+ * $FreeBSD$
+ */
+
+#include "opt_debug_lockf.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/proc.h>
+#include <sys/unistd.h>
+#include <sys/vnode.h>
+#include <sys/malloc.h>
+#include <sys/fcntl.h>
+#include <sys/lockf.h>
+
+#include <machine/limits.h>
+
+/*
+ * This variable controls the maximum number of processes that will
+ * be checked in doing deadlock detection.
+ */
+static int maxlockdepth = MAXDEPTH;
+
+#ifdef LOCKF_DEBUG
+#include <sys/kernel.h>
+#include <sys/sysctl.h>
+
+#include <ufs/ufs/quota.h>
+#include <ufs/ufs/inode.h>
+
+
+static int lockf_debug = 0;
+SYSCTL_INT(_debug, OID_AUTO, lockf_debug, CTLFLAG_RW, &lockf_debug, 0, "");
+#endif
+
+MALLOC_DEFINE(M_LOCKF, "lockf", "Byte-range locking structures");
+
+#define NOLOCKF (struct lockf *)0
+#define SELF 0x1
+#define OTHERS 0x2
+static int lf_clearlock(struct lockf *);
+static int lf_findoverlap(struct lockf *,
+ struct lockf *, int, struct lockf ***, struct lockf **);
+static struct lockf *
+ lf_getblock(struct lockf *);
+static int lf_getlock(struct lockf *, struct flock *);
+static int lf_setlock(struct lockf *);
+static void lf_split(struct lockf *, struct lockf *);
+static void lf_wakelock(struct lockf *);
+
+/*
+ * Advisory record locking support
+ */
+int
+lf_advlock(ap, head, size)
+ struct vop_advlock_args /* {
+ struct vnode *a_vp;
+ caddr_t a_id;
+ int a_op;
+ struct flock *a_fl;
+ int a_flags;
+ } */ *ap;
+ struct lockf **head;
+ u_quad_t size;
+{
+ register struct flock *fl = ap->a_fl;
+ register struct lockf *lock;
+ off_t start, end, oadd;
+ int error;
+
+ /*
+ * Convert the flock structure into a start and end.
+ */
+ switch (fl->l_whence) {
+
+ case SEEK_SET:
+ case SEEK_CUR:
+ /*
+ * Caller is responsible for adding any necessary offset
+ * when SEEK_CUR is used.
+ */
+ start = fl->l_start;
+ break;
+
+ case SEEK_END:
+ if (size > OFF_MAX ||
+ (fl->l_start > 0 && size > OFF_MAX - fl->l_start))
+ return (EOVERFLOW);
+ start = size + fl->l_start;
+ break;
+
+ default:
+ return (EINVAL);
+ }
+ if (start < 0)
+ return (EINVAL);
+ if (fl->l_len < 0) {
+ if (start == 0)
+ return (EINVAL);
+ end = start - 1;
+ start += fl->l_len;
+ if (start < 0)
+ return (EINVAL);
+ } else if (fl->l_len == 0)
+ end = -1;
+ else {
+ oadd = fl->l_len - 1;
+ if (oadd > OFF_MAX - start)
+ return (EOVERFLOW);
+ end = start + oadd;
+ }
+ /*
+ * Avoid the common case of unlocking when inode has no locks.
+ */
+ if (*head == (struct lockf *)0) {
+ if (ap->a_op != F_SETLK) {
+ fl->l_type = F_UNLCK;
+ return (0);
+ }
+ }
+ /*
+ * Create the lockf structure
+ */
+ MALLOC(lock, struct lockf *, sizeof *lock, M_LOCKF, M_WAITOK);
+ lock->lf_start = start;
+ lock->lf_end = end;
+ lock->lf_id = ap->a_id;
+ /*
+ * XXX The problem is that VTOI is ufs specific, so it will
+ * break LOCKF_DEBUG for all other FS's other than UFS because
+ * it casts the vnode->data ptr to struct inode *.
+ */
+/* lock->lf_inode = VTOI(ap->a_vp); */
+ lock->lf_inode = (struct inode *)0;
+ lock->lf_type = fl->l_type;
+ lock->lf_head = head;
+ lock->lf_next = (struct lockf *)0;
+ TAILQ_INIT(&lock->lf_blkhd);
+ lock->lf_flags = ap->a_flags;
+ /*
+ * Do the requested operation.
+ */
+ switch(ap->a_op) {
+ case F_SETLK:
+ return (lf_setlock(lock));
+
+ case F_UNLCK:
+ error = lf_clearlock(lock);
+ FREE(lock, M_LOCKF);
+ return (error);
+
+ case F_GETLK:
+ error = lf_getlock(lock, fl);
+ FREE(lock, M_LOCKF);
+ return (error);
+
+ default:
+ free(lock, M_LOCKF);
+ return (EINVAL);
+ }
+ /* NOTREACHED */
+}
+
+/*
+ * Set a byte-range lock.
+ */
+static int
+lf_setlock(lock)
+ register struct lockf *lock;
+{
+ register struct lockf *block;
+ struct lockf **head = lock->lf_head;
+ struct lockf **prev, *overlap, *ltmp;
+ static char lockstr[] = "lockf";
+ int ovcase, priority, needtolink, error;
+
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 1)
+ lf_print("lf_setlock", lock);
+#endif /* LOCKF_DEBUG */
+
+ /*
+ * Set the priority
+ */
+ priority = PLOCK;
+ if (lock->lf_type == F_WRLCK)
+ priority += 4;
+ priority |= PCATCH;
+ /*
+ * Scan lock list for this file looking for locks that would block us.
+ */
+ while ((block = lf_getblock(lock))) {
+ /*
+ * Free the structure and return if nonblocking.
+ */
+ if ((lock->lf_flags & F_WAIT) == 0) {
+ FREE(lock, M_LOCKF);
+ return (EAGAIN);
+ }
+ /*
+ * We are blocked. Since flock style locks cover
+ * the whole file, there is no chance for deadlock.
+ * For byte-range locks we must check for deadlock.
+ *
+ * Deadlock detection is done by looking through the
+ * wait channels to see if there are any cycles that
+ * involve us. MAXDEPTH is set just to make sure we
+ * do not go off into neverland.
+ */
+ if ((lock->lf_flags & F_POSIX) &&
+ (block->lf_flags & F_POSIX)) {
+ register struct proc *wproc;
+ struct thread *td;
+ register struct lockf *waitblock;
+ int i = 0;
+
+ /* The block is waiting on something */
+ /* XXXKSE this is not complete under threads */
+ wproc = (struct proc *)block->lf_id;
+ mtx_lock_spin(&sched_lock);
+ FOREACH_THREAD_IN_PROC(wproc, td) {
+ while (td->td_wchan &&
+ (td->td_wmesg == lockstr) &&
+ (i++ < maxlockdepth)) {
+ waitblock = (struct lockf *)td->td_wchan;
+ /* Get the owner of the blocking lock */
+ waitblock = waitblock->lf_next;
+ if ((waitblock->lf_flags & F_POSIX) == 0)
+ break;
+ wproc = (struct proc *)waitblock->lf_id;
+ if (wproc == (struct proc *)lock->lf_id) {
+ mtx_unlock_spin(&sched_lock);
+ free(lock, M_LOCKF);
+ return (EDEADLK);
+ }
+ }
+ }
+ mtx_unlock_spin(&sched_lock);
+ }
+ /*
+ * For flock type locks, we must first remove
+ * any shared locks that we hold before we sleep
+ * waiting for an exclusive lock.
+ */
+ if ((lock->lf_flags & F_FLOCK) &&
+ lock->lf_type == F_WRLCK) {
+ lock->lf_type = F_UNLCK;
+ (void) lf_clearlock(lock);
+ lock->lf_type = F_WRLCK;
+ }
+ /*
+ * Add our lock to the blocked list and sleep until we're free.
+ * Remember who blocked us (for deadlock detection).
+ */
+ lock->lf_next = block;
+ TAILQ_INSERT_TAIL(&block->lf_blkhd, lock, lf_block);
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 1) {
+ lf_print("lf_setlock: blocking on", block);
+ lf_printlist("lf_setlock", block);
+ }
+#endif /* LOCKF_DEBUG */
+ error = tsleep(lock, priority, lockstr, 0);
+ /*
+ * We may have been awakened by a signal and/or by a
+ * debugger continuing us (in which cases we must remove
+ * ourselves from the blocked list) and/or by another
+ * process releasing a lock (in which case we have
+ * already been removed from the blocked list and our
+ * lf_next field set to NOLOCKF).
+ */
+ if (lock->lf_next) {
+ TAILQ_REMOVE(&lock->lf_next->lf_blkhd, lock, lf_block);
+ lock->lf_next = NOLOCKF;
+ }
+ if (error) {
+ free(lock, M_LOCKF);
+ return (error);
+ }
+ }
+ /*
+ * No blocks!! Add the lock. Note that we will
+ * downgrade or upgrade any overlapping locks this
+ * process already owns.
+ *
+ * Skip over locks owned by other processes.
+ * Handle any locks that overlap and are owned by ourselves.
+ */
+ prev = head;
+ block = *head;
+ needtolink = 1;
+ for (;;) {
+ ovcase = lf_findoverlap(block, lock, SELF, &prev, &overlap);
+ if (ovcase)
+ block = overlap->lf_next;
+ /*
+ * Six cases:
+ * 0) no overlap
+ * 1) overlap == lock
+ * 2) overlap contains lock
+ * 3) lock contains overlap
+ * 4) overlap starts before lock
+ * 5) overlap ends after lock
+ */
+ switch (ovcase) {
+ case 0: /* no overlap */
+ if (needtolink) {
+ *prev = lock;
+ lock->lf_next = overlap;
+ }
+ break;
+
+ case 1: /* overlap == lock */
+ /*
+ * If downgrading lock, others may be
+ * able to acquire it.
+ */
+ if (lock->lf_type == F_RDLCK &&
+ overlap->lf_type == F_WRLCK)
+ lf_wakelock(overlap);
+ overlap->lf_type = lock->lf_type;
+ FREE(lock, M_LOCKF);
+ lock = overlap; /* for debug output below */
+ break;
+
+ case 2: /* overlap contains lock */
+ /*
+ * Check for common starting point and different types.
+ */
+ if (overlap->lf_type == lock->lf_type) {
+ free(lock, M_LOCKF);
+ lock = overlap; /* for debug output below */
+ break;
+ }
+ if (overlap->lf_start == lock->lf_start) {
+ *prev = lock;
+ lock->lf_next = overlap;
+ overlap->lf_start = lock->lf_end + 1;
+ } else
+ lf_split(overlap, lock);
+ lf_wakelock(overlap);
+ break;
+
+ case 3: /* lock contains overlap */
+ /*
+ * If downgrading lock, others may be able to
+ * acquire it, otherwise take the list.
+ */
+ if (lock->lf_type == F_RDLCK &&
+ overlap->lf_type == F_WRLCK) {
+ lf_wakelock(overlap);
+ } else {
+ while (!TAILQ_EMPTY(&overlap->lf_blkhd)) {
+ ltmp = TAILQ_FIRST(&overlap->lf_blkhd);
+ TAILQ_REMOVE(&overlap->lf_blkhd, ltmp,
+ lf_block);
+ TAILQ_INSERT_TAIL(&lock->lf_blkhd,
+ ltmp, lf_block);
+ ltmp->lf_next = lock;
+ }
+ }
+ /*
+ * Add the new lock if necessary and delete the overlap.
+ */
+ if (needtolink) {
+ *prev = lock;
+ lock->lf_next = overlap->lf_next;
+ prev = &lock->lf_next;
+ needtolink = 0;
+ } else
+ *prev = overlap->lf_next;
+ free(overlap, M_LOCKF);
+ continue;
+
+ case 4: /* overlap starts before lock */
+ /*
+ * Add lock after overlap on the list.
+ */
+ lock->lf_next = overlap->lf_next;
+ overlap->lf_next = lock;
+ overlap->lf_end = lock->lf_start - 1;
+ prev = &lock->lf_next;
+ lf_wakelock(overlap);
+ needtolink = 0;
+ continue;
+
+ case 5: /* overlap ends after lock */
+ /*
+ * Add the new lock before overlap.
+ */
+ if (needtolink) {
+ *prev = lock;
+ lock->lf_next = overlap;
+ }
+ overlap->lf_start = lock->lf_end + 1;
+ lf_wakelock(overlap);
+ break;
+ }
+ break;
+ }
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 1) {
+ lf_print("lf_setlock: got the lock", lock);
+ lf_printlist("lf_setlock", lock);
+ }
+#endif /* LOCKF_DEBUG */
+ return (0);
+}
+
+/*
+ * Remove a byte-range lock on an inode.
+ *
+ * Generally, find the lock (or an overlap to that lock)
+ * and remove it (or shrink it), then wakeup anyone we can.
+ */
+static int
+lf_clearlock(unlock)
+ register struct lockf *unlock;
+{
+ struct lockf **head = unlock->lf_head;
+ register struct lockf *lf = *head;
+ struct lockf *overlap, **prev;
+ int ovcase;
+
+ if (lf == NOLOCKF)
+ return (0);
+#ifdef LOCKF_DEBUG
+ if (unlock->lf_type != F_UNLCK)
+ panic("lf_clearlock: bad type");
+ if (lockf_debug & 1)
+ lf_print("lf_clearlock", unlock);
+#endif /* LOCKF_DEBUG */
+ prev = head;
+ while ((ovcase = lf_findoverlap(lf, unlock, SELF, &prev, &overlap))) {
+ /*
+ * Wakeup the list of locks to be retried.
+ */
+ lf_wakelock(overlap);
+
+ switch (ovcase) {
+
+ case 1: /* overlap == lock */
+ *prev = overlap->lf_next;
+ FREE(overlap, M_LOCKF);
+ break;
+
+ case 2: /* overlap contains lock: split it */
+ if (overlap->lf_start == unlock->lf_start) {
+ overlap->lf_start = unlock->lf_end + 1;
+ break;
+ }
+ lf_split(overlap, unlock);
+ overlap->lf_next = unlock->lf_next;
+ break;
+
+ case 3: /* lock contains overlap */
+ *prev = overlap->lf_next;
+ lf = overlap->lf_next;
+ free(overlap, M_LOCKF);
+ continue;
+
+ case 4: /* overlap starts before lock */
+ overlap->lf_end = unlock->lf_start - 1;
+ prev = &overlap->lf_next;
+ lf = overlap->lf_next;
+ continue;
+
+ case 5: /* overlap ends after lock */
+ overlap->lf_start = unlock->lf_end + 1;
+ break;
+ }
+ break;
+ }
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 1)
+ lf_printlist("lf_clearlock", unlock);
+#endif /* LOCKF_DEBUG */
+ return (0);
+}
+
+/*
+ * Check whether there is a blocking lock,
+ * and if so return its process identifier.
+ */
+static int
+lf_getlock(lock, fl)
+ register struct lockf *lock;
+ register struct flock *fl;
+{
+ register struct lockf *block;
+
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 1)
+ lf_print("lf_getlock", lock);
+#endif /* LOCKF_DEBUG */
+
+ if ((block = lf_getblock(lock))) {
+ fl->l_type = block->lf_type;
+ fl->l_whence = SEEK_SET;
+ fl->l_start = block->lf_start;
+ if (block->lf_end == -1)
+ fl->l_len = 0;
+ else
+ fl->l_len = block->lf_end - block->lf_start + 1;
+ if (block->lf_flags & F_POSIX)
+ fl->l_pid = ((struct proc *)(block->lf_id))->p_pid;
+ else
+ fl->l_pid = -1;
+ } else {
+ fl->l_type = F_UNLCK;
+ }
+ return (0);
+}
+
+/*
+ * Walk the list of locks for an inode and
+ * return the first blocking lock.
+ */
+static struct lockf *
+lf_getblock(lock)
+ register struct lockf *lock;
+{
+ struct lockf **prev, *overlap, *lf = *(lock->lf_head);
+ int ovcase;
+
+ prev = lock->lf_head;
+ while ((ovcase = lf_findoverlap(lf, lock, OTHERS, &prev, &overlap))) {
+ /*
+ * We've found an overlap, see if it blocks us
+ */
+ if ((lock->lf_type == F_WRLCK || overlap->lf_type == F_WRLCK))
+ return (overlap);
+ /*
+ * Nope, point to the next one on the list and
+ * see if it blocks us
+ */
+ lf = overlap->lf_next;
+ }
+ return (NOLOCKF);
+}
+
+/*
+ * Walk the list of locks for an inode to
+ * find an overlapping lock (if any).
+ *
+ * NOTE: this returns only the FIRST overlapping lock. There
+ * may be more than one.
+ */
+static int
+lf_findoverlap(lf, lock, type, prev, overlap)
+ register struct lockf *lf;
+ struct lockf *lock;
+ int type;
+ struct lockf ***prev;
+ struct lockf **overlap;
+{
+ off_t start, end;
+
+ *overlap = lf;
+ if (lf == NOLOCKF)
+ return (0);
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 2)
+ lf_print("lf_findoverlap: looking for overlap in", lock);
+#endif /* LOCKF_DEBUG */
+ start = lock->lf_start;
+ end = lock->lf_end;
+ while (lf != NOLOCKF) {
+ if (((type & SELF) && lf->lf_id != lock->lf_id) ||
+ ((type & OTHERS) && lf->lf_id == lock->lf_id)) {
+ *prev = &lf->lf_next;
+ *overlap = lf = lf->lf_next;
+ continue;
+ }
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 2)
+ lf_print("\tchecking", lf);
+#endif /* LOCKF_DEBUG */
+ /*
+ * OK, check for overlap
+ *
+ * Six cases:
+ * 0) no overlap
+ * 1) overlap == lock
+ * 2) overlap contains lock
+ * 3) lock contains overlap
+ * 4) overlap starts before lock
+ * 5) overlap ends after lock
+ */
+ if ((lf->lf_end != -1 && start > lf->lf_end) ||
+ (end != -1 && lf->lf_start > end)) {
+ /* Case 0 */
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 2)
+ printf("no overlap\n");
+#endif /* LOCKF_DEBUG */
+ if ((type & SELF) && end != -1 && lf->lf_start > end)
+ return (0);
+ *prev = &lf->lf_next;
+ *overlap = lf = lf->lf_next;
+ continue;
+ }
+ if ((lf->lf_start == start) && (lf->lf_end == end)) {
+ /* Case 1 */
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 2)
+ printf("overlap == lock\n");
+#endif /* LOCKF_DEBUG */
+ return (1);
+ }
+ if ((lf->lf_start <= start) &&
+ (end != -1) &&
+ ((lf->lf_end >= end) || (lf->lf_end == -1))) {
+ /* Case 2 */
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 2)
+ printf("overlap contains lock\n");
+#endif /* LOCKF_DEBUG */
+ return (2);
+ }
+ if (start <= lf->lf_start &&
+ (end == -1 ||
+ (lf->lf_end != -1 && end >= lf->lf_end))) {
+ /* Case 3 */
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 2)
+ printf("lock contains overlap\n");
+#endif /* LOCKF_DEBUG */
+ return (3);
+ }
+ if ((lf->lf_start < start) &&
+ ((lf->lf_end >= start) || (lf->lf_end == -1))) {
+ /* Case 4 */
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 2)
+ printf("overlap starts before lock\n");
+#endif /* LOCKF_DEBUG */
+ return (4);
+ }
+ if ((lf->lf_start > start) &&
+ (end != -1) &&
+ ((lf->lf_end > end) || (lf->lf_end == -1))) {
+ /* Case 5 */
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 2)
+ printf("overlap ends after lock\n");
+#endif /* LOCKF_DEBUG */
+ return (5);
+ }
+ panic("lf_findoverlap: default");
+ }
+ return (0);
+}
+
+/*
+ * Split a lock and a contained region into
+ * two or three locks as necessary.
+ */
+static void
+lf_split(lock1, lock2)
+ register struct lockf *lock1;
+ register struct lockf *lock2;
+{
+ register struct lockf *splitlock;
+
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 2) {
+ lf_print("lf_split", lock1);
+ lf_print("splitting from", lock2);
+ }
+#endif /* LOCKF_DEBUG */
+ /*
+ * Check to see if spliting into only two pieces.
+ */
+ if (lock1->lf_start == lock2->lf_start) {
+ lock1->lf_start = lock2->lf_end + 1;
+ lock2->lf_next = lock1;
+ return;
+ }
+ if (lock1->lf_end == lock2->lf_end) {
+ lock1->lf_end = lock2->lf_start - 1;
+ lock2->lf_next = lock1->lf_next;
+ lock1->lf_next = lock2;
+ return;
+ }
+ /*
+ * Make a new lock consisting of the last part of
+ * the encompassing lock
+ */
+ MALLOC(splitlock, struct lockf *, sizeof *splitlock, M_LOCKF, M_WAITOK);
+ bcopy(lock1, splitlock, sizeof *splitlock);
+ splitlock->lf_start = lock2->lf_end + 1;
+ TAILQ_INIT(&splitlock->lf_blkhd);
+ lock1->lf_end = lock2->lf_start - 1;
+ /*
+ * OK, now link it in
+ */
+ splitlock->lf_next = lock1->lf_next;
+ lock2->lf_next = splitlock;
+ lock1->lf_next = lock2;
+}
+
+/*
+ * Wakeup a blocklist
+ */
+static void
+lf_wakelock(listhead)
+ struct lockf *listhead;
+{
+ register struct lockf *wakelock;
+
+ while (!TAILQ_EMPTY(&listhead->lf_blkhd)) {
+ wakelock = TAILQ_FIRST(&listhead->lf_blkhd);
+ TAILQ_REMOVE(&listhead->lf_blkhd, wakelock, lf_block);
+ wakelock->lf_next = NOLOCKF;
+#ifdef LOCKF_DEBUG
+ if (lockf_debug & 2)
+ lf_print("lf_wakelock: awakening", wakelock);
+#endif /* LOCKF_DEBUG */
+ wakeup(wakelock);
+ }
+}
+
+#ifdef LOCKF_DEBUG
+/*
+ * Print out a lock.
+ */
+void
+lf_print(tag, lock)
+ char *tag;
+ register struct lockf *lock;
+{
+
+ printf("%s: lock %p for ", tag, (void *)lock);
+ if (lock->lf_flags & F_POSIX)
+ printf("proc %ld", (long)((struct proc *)lock->lf_id)->p_pid);
+ else
+ printf("id %p", (void *)lock->lf_id);
+ if (lock->lf_inode != (struct inode *)0)
+ /* XXX no %qd in kernel. Truncate. */
+ printf(" in ino %lu on dev <%d, %d>, %s, start %ld, end %ld",
+ (u_long)lock->lf_inode->i_number,
+ major(lock->lf_inode->i_dev),
+ minor(lock->lf_inode->i_dev),
+ lock->lf_type == F_RDLCK ? "shared" :
+ lock->lf_type == F_WRLCK ? "exclusive" :
+ lock->lf_type == F_UNLCK ? "unlock" :
+ "unknown", (long)lock->lf_start, (long)lock->lf_end);
+ else
+ printf(" %s, start %ld, end %ld",
+ lock->lf_type == F_RDLCK ? "shared" :
+ lock->lf_type == F_WRLCK ? "exclusive" :
+ lock->lf_type == F_UNLCK ? "unlock" :
+ "unknown", (long)lock->lf_start, (long)lock->lf_end);
+ if (!TAILQ_EMPTY(&lock->lf_blkhd))
+ printf(" block %p\n", (void *)TAILQ_FIRST(&lock->lf_blkhd));
+ else
+ printf("\n");
+}
+
+void
+lf_printlist(tag, lock)
+ char *tag;
+ struct lockf *lock;
+{
+ register struct lockf *lf, *blk;
+
+ if (lock->lf_inode == (struct inode *)0)
+ return;
+
+ printf("%s: Lock list for ino %lu on dev <%d, %d>:\n",
+ tag, (u_long)lock->lf_inode->i_number,
+ major(lock->lf_inode->i_dev),
+ minor(lock->lf_inode->i_dev));
+ for (lf = lock->lf_inode->i_lockf; lf; lf = lf->lf_next) {
+ printf("\tlock %p for ",(void *)lf);
+ if (lf->lf_flags & F_POSIX)
+ printf("proc %ld",
+ (long)((struct proc *)lf->lf_id)->p_pid);
+ else
+ printf("id %p", (void *)lf->lf_id);
+ /* XXX no %qd in kernel. Truncate. */
+ printf(", %s, start %ld, end %ld",
+ lf->lf_type == F_RDLCK ? "shared" :
+ lf->lf_type == F_WRLCK ? "exclusive" :
+ lf->lf_type == F_UNLCK ? "unlock" :
+ "unknown", (long)lf->lf_start, (long)lf->lf_end);
+ TAILQ_FOREACH(blk, &lf->lf_blkhd, lf_block) {
+ printf("\n\t\tlock request %p for ", (void *)blk);
+ if (blk->lf_flags & F_POSIX)
+ printf("proc %ld",
+ (long)((struct proc *)blk->lf_id)->p_pid);
+ else
+ printf("id %p", (void *)blk->lf_id);
+ /* XXX no %qd in kernel. Truncate. */
+ printf(", %s, start %ld, end %ld",
+ blk->lf_type == F_RDLCK ? "shared" :
+ blk->lf_type == F_WRLCK ? "exclusive" :
+ blk->lf_type == F_UNLCK ? "unlock" :
+ "unknown", (long)blk->lf_start,
+ (long)blk->lf_end);
+ if (!TAILQ_EMPTY(&blk->lf_blkhd))
+ panic("lf_printlist: bad list");
+ }
+ printf("\n");
+ }
+}
+#endif /* LOCKF_DEBUG */
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