diff options
Diffstat (limited to 'sbin/hastd/rangelock.c')
-rw-r--r-- | sbin/hastd/rangelock.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/sbin/hastd/rangelock.c b/sbin/hastd/rangelock.c new file mode 100644 index 0000000..02247d6 --- /dev/null +++ b/sbin/hastd/rangelock.c @@ -0,0 +1,137 @@ +/*- + * Copyright (c) 2010 The FreeBSD Foundation + * All rights reserved. + * + * This software was developed by Pawel Jakub Dawidek under sponsorship from + * the FreeBSD Foundation. + * + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/queue.h> + +#include <assert.h> +#include <stdbool.h> +#include <stdlib.h> +#include <unistd.h> + +#include "rangelock.h" + +#define RANGELOCKS_MAGIC 0x94310c +struct rangelocks { + int rls_magic; /* Magic value. */ + TAILQ_HEAD(, rlock) rls_locks; /* List of locked ranges. */ +}; + +struct rlock { + off_t rl_start; + off_t rl_end; + TAILQ_ENTRY(rlock) rl_next; +}; + +int +rangelock_init(struct rangelocks **rlsp) +{ + struct rangelocks *rls; + + assert(rlsp != NULL); + + rls = malloc(sizeof(*rls)); + if (rls == NULL) + return (-1); + + TAILQ_INIT(&rls->rls_locks); + + rls->rls_magic = RANGELOCKS_MAGIC; + *rlsp = rls; + + return (0); +} + +void +rangelock_free(struct rangelocks *rls) +{ + struct rlock *rl; + + assert(rls->rls_magic == RANGELOCKS_MAGIC); + + rls->rls_magic = 0; + + while ((rl = TAILQ_FIRST(&rls->rls_locks)) != NULL) { + TAILQ_REMOVE(&rls->rls_locks, rl, rl_next); + free(rl); + } + free(rls); +} + +int +rangelock_add(struct rangelocks *rls, off_t offset, off_t length) +{ + struct rlock *rl; + + assert(rls->rls_magic == RANGELOCKS_MAGIC); + + rl = malloc(sizeof(*rl)); + if (rl == NULL) + return (-1); + rl->rl_start = offset; + rl->rl_end = offset + length; + TAILQ_INSERT_TAIL(&rls->rls_locks, rl, rl_next); + return (0); +} + +void +rangelock_del(struct rangelocks *rls, off_t offset, off_t length) +{ + struct rlock *rl; + + assert(rls->rls_magic == RANGELOCKS_MAGIC); + + TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) { + if (rl->rl_start == offset && rl->rl_end == offset + length) + break; + } + assert(rl != NULL); + TAILQ_REMOVE(&rls->rls_locks, rl, rl_next); + free(rl); +} + +bool +rangelock_islocked(struct rangelocks *rls, off_t offset, off_t length) +{ + struct rlock *rl; + + assert(rls->rls_magic == RANGELOCKS_MAGIC); + + TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) { + if (rl->rl_start >= offset && rl->rl_start < offset + length) + break; + else if (rl->rl_end > offset && rl->rl_end <= offset + length) + break; + else if (rl->rl_start < offset && rl->rl_end > offset + length) + break; + } + return (rl != NULL); +} |