diff options
Diffstat (limited to 'sys/kern/vfs_mount.c')
| -rw-r--r-- | sys/kern/vfs_mount.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c new file mode 100644 index 0000000..d733a3f --- /dev/null +++ b/sys/kern/vfs_mount.c @@ -0,0 +1,116 @@ +/* + * 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 <os/mount.h> +#include <os/vfs.h> +#include <lib/stdbool.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 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; + } + + mp = kalloc(sizeof(*mp)); + if (mp == NULL) { + return -ENOMEM; + } + + mp->fip = fip; + error = vnode_init(&mp->vp, VDIR); + if (error < 0) { + kfree(mp); + return error; + } + + /* + * TODO: We'd need to do a namei() here, add by-path + */ + spinlock_acquire(&mount_lock, false); + TAILQ_INSERT_TAIL(&mountlist, mp, link); + spinlock_release(&mount_lock, false); + return 0; +} |
