diff options
Diffstat (limited to 'sys/fs/devfs/devfs_dir.c')
| -rw-r--r-- | sys/fs/devfs/devfs_dir.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/sys/fs/devfs/devfs_dir.c b/sys/fs/devfs/devfs_dir.c new file mode 100644 index 000000000000..c497e5542588 --- /dev/null +++ b/sys/fs/devfs/devfs_dir.c @@ -0,0 +1,175 @@ +/*- + * Copyright (c) 2010 Jaakko Heinonen <jh@FreeBSD.org> + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. + * + * $FreeBSD$ + */ + +#include <sys/param.h> +#include <sys/conf.h> +#include <sys/types.h> +#include <sys/kernel.h> +#include <sys/libkern.h> +#include <sys/lock.h> +#include <sys/malloc.h> +#include <sys/mutex.h> +#include <sys/queue.h> +#include <sys/systm.h> +#include <sys/sx.h> + +#include <fs/devfs/devfs.h> +#include <fs/devfs/devfs_int.h> + +struct dirlistent { + char *dir; + int refcnt; + LIST_ENTRY(dirlistent) link; +}; + +static LIST_HEAD(, dirlistent) devfs_dirlist = + LIST_HEAD_INITIALIZER(devfs_dirlist); + +static MALLOC_DEFINE(M_DEVFS4, "DEVFS4", "DEVFS directory list"); + +static struct mtx dirlist_mtx; +MTX_SYSINIT(dirlist_mtx, &dirlist_mtx, "devfs dirlist lock", MTX_DEF); + +/* Returns 1 if the path is in the directory list. */ +int +devfs_dir_find(const char *path) +{ + struct dirlistent *dle; + + mtx_lock(&dirlist_mtx); + LIST_FOREACH(dle, &devfs_dirlist, link) { + if (devfs_pathpath(dle->dir, path) != 0) { + mtx_unlock(&dirlist_mtx); + return (1); + } + } + mtx_unlock(&dirlist_mtx); + + return (0); +} + +static struct dirlistent * +devfs_dir_findent_locked(const char *dir) +{ + struct dirlistent *dle; + + mtx_assert(&dirlist_mtx, MA_OWNED); + + LIST_FOREACH(dle, &devfs_dirlist, link) { + if (strcmp(dir, dle->dir) == 0) + return (dle); + } + + return (NULL); +} + +static void +devfs_dir_ref(const char *dir) +{ + struct dirlistent *dle, *dle_new; + + if (*dir == '\0') + return; + + dle_new = malloc(sizeof(*dle), M_DEVFS4, M_WAITOK); + dle_new->dir = strdup(dir, M_DEVFS4); + dle_new->refcnt = 1; + + mtx_lock(&dirlist_mtx); + dle = devfs_dir_findent_locked(dir); + if (dle != NULL) { + dle->refcnt++; + mtx_unlock(&dirlist_mtx); + free(dle_new->dir, M_DEVFS4); + free(dle_new, M_DEVFS4); + return; + } + LIST_INSERT_HEAD(&devfs_dirlist, dle_new, link); + mtx_unlock(&dirlist_mtx); +} + +void +devfs_dir_ref_de(struct devfs_mount *dm, struct devfs_dirent *de) +{ + char dirname[SPECNAMELEN + 1], *namep; + + namep = devfs_fqpn(dirname, dm, de, NULL); + KASSERT(namep != NULL, ("devfs_ref_dir_de: NULL namep")); + + devfs_dir_ref(namep); +} + +static void +devfs_dir_unref(const char *dir) +{ + struct dirlistent *dle; + + if (*dir == '\0') + return; + + mtx_lock(&dirlist_mtx); + dle = devfs_dir_findent_locked(dir); + KASSERT(dle != NULL, ("devfs_dir_unref: dir %s not referenced", dir)); + dle->refcnt--; + KASSERT(dle->refcnt >= 0, ("devfs_dir_unref: negative refcnt")); + if (dle->refcnt == 0) { + LIST_REMOVE(dle, link); + mtx_unlock(&dirlist_mtx); + free(dle->dir, M_DEVFS4); + free(dle, M_DEVFS4); + } else + mtx_unlock(&dirlist_mtx); +} + +void +devfs_dir_unref_de(struct devfs_mount *dm, struct devfs_dirent *de) +{ + char dirname[SPECNAMELEN + 1], *namep; + + namep = devfs_fqpn(dirname, dm, de, NULL); + KASSERT(namep != NULL, ("devfs_unref_dir_de: NULL namep")); + + devfs_dir_unref(namep); +} + +/* Returns 1 if the path p1 contains the path p2. */ +int +devfs_pathpath(const char *p1, const char *p2) +{ + + for (;;p1++, p2++) { + if (*p1 != *p2) { + if (*p1 == '/' && *p2 == '\0') + return (1); + else + return (0); + } else if (*p1 == '\0') + return (1); + } + /* NOTREACHED */ +} |