146 lines
3.7 KiB
C
146 lines
3.7 KiB
C
/*
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* Copyright (c) 2014
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* The President and Fellows of Harvard College.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <types.h>
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#include <kern/errno.h>
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#include <synch.h>
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#define SEMFS_INLINE
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#include "semfs.h"
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////////////////////////////////////////////////////////////
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// semfs_sem
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/*
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* Constructor for semfs_sem.
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*/
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struct semfs_sem *
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semfs_sem_create(const char *name)
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{
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struct semfs_sem *sem;
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char lockname[32];
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char cvname[32];
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snprintf(lockname, sizeof(lockname), "sem:l.%s", name);
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snprintf(cvname, sizeof(cvname), "sem:%s", name);
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sem = kmalloc(sizeof(*sem));
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if (sem == NULL) {
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goto fail_return;
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}
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sem->sems_lock = lock_create(lockname);
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if (sem->sems_lock == NULL) {
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goto fail_sem;
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}
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sem->sems_cv = cv_create(cvname);
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if (sem->sems_cv == NULL) {
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goto fail_lock;
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}
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sem->sems_count = 0;
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sem->sems_hasvnode = false;
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sem->sems_linked = false;
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return sem;
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fail_lock:
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lock_destroy(sem->sems_lock);
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fail_sem:
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kfree(sem);
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fail_return:
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return NULL;
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}
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/*
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* Destructor for semfs_sem.
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*/
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void
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semfs_sem_destroy(struct semfs_sem *sem)
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{
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cv_destroy(sem->sems_cv);
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lock_destroy(sem->sems_lock);
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kfree(sem);
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}
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/*
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* Helper to insert a semfs_sem into the semaphore table.
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*/
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int
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semfs_sem_insert(struct semfs *semfs, struct semfs_sem *sem, unsigned *ret)
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{
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unsigned i, num;
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KASSERT(lock_do_i_hold(semfs->semfs_tablelock));
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num = semfs_semarray_num(semfs->semfs_sems);
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if (num == SEMFS_ROOTDIR) {
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/* Too many */
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return ENOSPC;
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}
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for (i=0; i<num; i++) {
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if (semfs_semarray_get(semfs->semfs_sems, i) == NULL) {
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semfs_semarray_set(semfs->semfs_sems, i, sem);
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*ret = i;
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return 0;
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}
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}
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return semfs_semarray_add(semfs->semfs_sems, sem, ret);
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}
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////////////////////////////////////////////////////////////
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// semfs_direntry
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/*
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* Constructor for semfs_direntry.
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*/
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struct semfs_direntry *
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semfs_direntry_create(const char *name, unsigned semnum)
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{
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struct semfs_direntry *dent;
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dent = kmalloc(sizeof(*dent));
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if (dent == NULL) {
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return NULL;
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}
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dent->semd_name = kstrdup(name);
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if (dent->semd_name == NULL) {
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kfree(dent);
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return NULL;
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}
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dent->semd_semnum = semnum;
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return dent;
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}
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/*
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* Destructor for semfs_direntry.
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*/
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void
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semfs_direntry_destroy(struct semfs_direntry *dent)
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{
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kfree(dent->semd_name);
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kfree(dent);
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}
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