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/*
* Copyright (c) 2025 Ian Marco Moffett and the Osmora Team.
* 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. Neither the name of Hyra 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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/types.h>
#include <sys/errno.h>
#include <sys/param.h>
#include <kern/spinlock.h>
#include <kern/panic.h>
#include <kern/mount.h>
#include <kern/vfs.h>
#include <lib/stdbool.h>
#include <lib/string.h>
#include <vm/kalloc.h>
/*
* We can't quite distribute this lock in a sane way without
* complicating things significantly and thus the practicality
* of such is questionable. Unfortunately, having a global lock
* comes with some performance penalties due to contention. At
* the very least, we can prevent it from bouncing around between
* caches on multicore systems by aligning it to a cacheline boundary.
*/
__cacheline_aligned
static struct spinlock mount_lock;
/* Mount list */
static TAILQ_HEAD(, mount) mountlist;
static bool is_mountlist_init = false;
/*
* Initialize the mountlist
*/
static void
mountlist_init(void)
{
if (is_mountlist_init) {
return;
}
TAILQ_INIT(&mountlist);
if (spinlock_init("mount", &mount_lock) != 0) {
panic("mount: failed to initialize mountlist\n");
}
is_mountlist_init = true;
}
int
mount(struct mount_args *margs)
{
struct fs_info *fip;
struct vfsops *vfsops;
struct mount *mp;
int error;
if (margs == NULL) {
return -EINVAL;
}
if (margs->target == NULL || margs->fstype == NULL) {
return -EINVAL;
}
/* Initialize the mountlist if needed */
if (!is_mountlist_init) {
mountlist_init();
}
error = vfs_byname(margs->fstype, &fip);
if (error != 0) {
return error;
}
vfsops = fip->vfsops;
if (vfsops->mount == NULL) {
return -ENOTSUP;
}
mp = kalloc(sizeof(*mp));
if (mp == NULL) {
return -ENOMEM;
}
mp->fip = fip;
error = vfsops->mount(fip, mp);
if (error < 0) {
kfree(mp);
return error;
}
/*
* TODO: We'd need to do a namei() here, add by-path
*/
spinlock_acquire(&mount_lock, true);
TAILQ_INSERT_TAIL(&mountlist, mp, link);
spinlock_release(&mount_lock, true);
return 0;
}
/*
* XXX: Currently we are looking up entries by the fstype.
* This must be updated to actual name-based lookups
* in future revisions of rv7
*/
int
mount_lookup(const char *name, struct mount **mres)
{
struct fs_info *fip;
struct mount *iter, *mount = NULL;
if (name == NULL || mres == NULL) {
return -EINVAL;
}
spinlock_acquire(&mount_lock, true);
TAILQ_FOREACH(iter, &mountlist, link) {
fip = iter->fip;
if (__likely(*name != *fip->name)) {
continue;
}
if (strcmp(fip->name, name) == 0) {
mount = iter;
break;
}
}
spinlock_release(&mount_lock, true);
if (mount == NULL) {
return -ENOENT;
}
*mres = mount;
return 0;
}
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