NetBSD-5.0.2/sys/ufs/mfs/mfs_vfsops.c
/* $NetBSD: mfs_vfsops.c,v 1.98 2008/06/28 01:34:05 rumble Exp $ */
/*
* Copyright (c) 1989, 1990, 1993, 1994
* The Regents of the University of California. 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 the University 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 REGENTS 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 REGENTS 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.
*
* @(#)mfs_vfsops.c 8.11 (Berkeley) 6/19/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: mfs_vfsops.c,v 1.98 2008/06/28 01:34:05 rumble Exp $");
#if defined(_KERNEL_OPT)
#include "opt_compat_netbsd.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/bufq.h>
#include <sys/mount.h>
#include <sys/signalvar.h>
#include <sys/vnode.h>
#include <sys/kmem.h>
#include <sys/module.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/specfs/specdev.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>
#include <ufs/mfs/mfsnode.h>
#include <ufs/mfs/mfs_extern.h>
MODULE(MODULE_CLASS_VFS, mfs, NULL);
void * mfs_rootbase; /* address of mini-root in kernel virtual memory */
u_long mfs_rootsize; /* size of mini-root in bytes */
kmutex_t mfs_lock; /* global lock */
static int mfs_minor; /* used for building internal dev_t */
static int mfs_initcnt;
extern int (**mfs_vnodeop_p)(void *);
static struct sysctllog *mfs_sysctl_log;
/*
* mfs vfs operations.
*/
extern const struct vnodeopv_desc mfs_vnodeop_opv_desc;
const struct vnodeopv_desc * const mfs_vnodeopv_descs[] = {
&mfs_vnodeop_opv_desc,
NULL,
};
struct vfsops mfs_vfsops = {
MOUNT_MFS,
sizeof (struct mfs_args),
mfs_mount,
mfs_start,
ffs_unmount,
ufs_root,
ufs_quotactl,
mfs_statvfs,
ffs_sync,
ffs_vget,
ffs_fhtovp,
ffs_vptofh,
mfs_init,
mfs_reinit,
mfs_done,
NULL,
(int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp,
vfs_stdextattrctl,
(void *)eopnotsupp, /* vfs_suspendctl */
genfs_renamelock_enter,
genfs_renamelock_exit,
(void *)eopnotsupp,
mfs_vnodeopv_descs,
0,
{ NULL, NULL },
};
static int
mfs_modcmd(modcmd_t cmd, void *arg)
{
int error;
switch (cmd) {
case MODULE_CMD_INIT:
error = vfs_attach(&mfs_vfsops);
if (error != 0)
break;
sysctl_createv(&mfs_sysctl_log, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "vfs", NULL,
NULL, 0, NULL, 0,
CTL_VFS, CTL_EOL);
sysctl_createv(&mfs_sysctl_log, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_ALIAS,
CTLTYPE_NODE, "mfs",
SYSCTL_DESCR("Memory based file system"),
NULL, 1, NULL, 0,
CTL_VFS, 3, CTL_EOL);
/*
* XXX the "1" and the "3" above could be dynamic, thereby
* eliminating one more instance of the "number to vfs"
* mapping problem, but they are in order as taken from
* sys/mount.h
*/
break;
case MODULE_CMD_FINI:
error = vfs_detach(&mfs_vfsops);
if (error != 0)
break;
sysctl_teardown(&mfs_sysctl_log);
break;
default:
error = ENOTTY;
break;
}
return (error);
}
/*
* Memory based filesystem initialization.
*/
void
mfs_init(void)
{
if (mfs_initcnt++ == 0) {
mutex_init(&mfs_lock, MUTEX_DEFAULT, IPL_NONE);
ffs_init();
}
}
void
mfs_reinit(void)
{
ffs_reinit();
}
void
mfs_done(void)
{
if (--mfs_initcnt == 0) {
ffs_done();
mutex_destroy(&mfs_lock);
}
}
/*
* Called by main() when mfs is going to be mounted as root.
*/
int
mfs_mountroot(void)
{
struct fs *fs;
struct mount *mp;
struct lwp *l = curlwp; /* XXX */
struct ufsmount *ump;
struct mfsnode *mfsp;
int error = 0;
if ((error = vfs_rootmountalloc(MOUNT_MFS, "mfs_root", &mp))) {
vrele(rootvp);
return (error);
}
mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP);
rootvp->v_data = mfsp;
rootvp->v_op = mfs_vnodeop_p;
rootvp->v_tag = VT_MFS;
mfsp->mfs_baseoff = mfs_rootbase;
mfsp->mfs_size = mfs_rootsize;
mfsp->mfs_vnode = rootvp;
mfsp->mfs_proc = NULL; /* indicate kernel space */
mfsp->mfs_shutdown = 0;
cv_init(&mfsp->mfs_cv, "mfs");
mfsp->mfs_refcnt = 1;
bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0);
if ((error = ffs_mountfs(rootvp, mp, l)) != 0) {
vfs_unbusy(mp, false, NULL);
bufq_free(mfsp->mfs_buflist);
vfs_destroy(mp);
kmem_free(mfsp, sizeof(*mfsp));
return (error);
}
mutex_enter(&mountlist_lock);
CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
mutex_exit(&mountlist_lock);
mp->mnt_vnodecovered = NULLVP;
ump = VFSTOUFS(mp);
fs = ump->um_fs;
(void) copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0);
(void)ffs_statvfs(mp, &mp->mnt_stat);
vfs_unbusy(mp, false, NULL);
return (0);
}
/*
* This is called early in boot to set the base address and size
* of the mini-root.
*/
int
mfs_initminiroot(void *base)
{
struct fs *fs = (struct fs *)((char *)base + SBLOCK_UFS1);
/* check for valid super block */
if (fs->fs_magic != FS_UFS1_MAGIC || fs->fs_bsize > MAXBSIZE ||
fs->fs_bsize < sizeof(struct fs))
return (0);
mountroot = mfs_mountroot;
mfs_rootbase = base;
mfs_rootsize = fs->fs_fsize * fs->fs_size;
rootdev = makedev(255, mfs_minor);
mfs_minor++;
return (mfs_rootsize);
}
/*
* VFS Operations.
*
* mount system call
*/
/* ARGSUSED */
int
mfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
{
struct lwp *l = curlwp;
struct vnode *devvp;
struct mfs_args *args = data;
struct ufsmount *ump;
struct fs *fs;
struct mfsnode *mfsp;
struct proc *p;
int flags, error = 0;
if (*data_len < sizeof *args)
return EINVAL;
p = l->l_proc;
if (mp->mnt_flag & MNT_GETARGS) {
struct vnode *vp;
ump = VFSTOUFS(mp);
if (ump == NULL)
return EIO;
vp = ump->um_devvp;
if (vp == NULL)
return EIO;
mfsp = VTOMFS(vp);
if (mfsp == NULL)
return EIO;
args->fspec = NULL;
args->base = mfsp->mfs_baseoff;
args->size = mfsp->mfs_size;
*data_len = sizeof *args;
return 0;
}
/*
* XXX turn off async to avoid hangs when writing lots of data.
* the problem is that MFS needs to allocate pages to clean pages,
* so if we wait until the last minute to clean pages then there
* may not be any pages available to do the cleaning.
* ... and since the default partially-synchronous mode turns out
* to not be sufficient under heavy load, make it full synchronous.
*/
mp->mnt_flag &= ~MNT_ASYNC;
mp->mnt_flag |= MNT_SYNCHRONOUS;
/*
* If updating, check whether changing from read-only to
* read/write; if there is no device name, that's all we do.
*/
if (mp->mnt_flag & MNT_UPDATE) {
ump = VFSTOUFS(mp);
fs = ump->um_fs;
if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
flags = WRITECLOSE;
if (mp->mnt_flag & MNT_FORCE)
flags |= FORCECLOSE;
error = ffs_flushfiles(mp, flags, l);
if (error)
return (error);
}
if (fs->fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR))
fs->fs_ronly = 0;
if (args->fspec == NULL)
return EINVAL;
return (0);
}
error = getnewvnode(VT_MFS, (struct mount *)0, mfs_vnodeop_p, &devvp);
if (error)
return (error);
devvp->v_vflag |= VV_MPSAFE;
devvp->v_type = VBLK;
spec_node_init(devvp, makedev(255, mfs_minor));
mfs_minor++;
mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP);
devvp->v_data = mfsp;
mfsp->mfs_baseoff = args->base;
mfsp->mfs_size = args->size;
mfsp->mfs_vnode = devvp;
mfsp->mfs_proc = p;
mfsp->mfs_shutdown = 0;
cv_init(&mfsp->mfs_cv, "mfsidl");
mfsp->mfs_refcnt = 1;
bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0);
if ((error = ffs_mountfs(devvp, mp, l)) != 0) {
mfsp->mfs_shutdown = 1;
vrele(devvp);
return (error);
}
ump = VFSTOUFS(mp);
fs = ump->um_fs;
error = set_statvfs_info(path, UIO_USERSPACE, args->fspec,
UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l);
if (error)
return error;
(void)strncpy(fs->fs_fsmnt, mp->mnt_stat.f_mntonname,
sizeof(fs->fs_fsmnt));
fs->fs_fsmnt[sizeof(fs->fs_fsmnt) - 1] = '\0';
/* XXX: cleanup on error */
return 0;
}
/*
* Used to grab the process and keep it in the kernel to service
* memory filesystem I/O requests.
*
* Loop servicing I/O requests.
* Copy the requested data into or out of the memory filesystem
* address space.
*/
/* ARGSUSED */
int
mfs_start(struct mount *mp, int flags)
{
struct vnode *vp;
struct mfsnode *mfsp;
struct proc *p;
struct buf *bp;
void *base;
int sleepreturn = 0, refcnt, error;
ksiginfoq_t kq;
/*
* Ensure that file system is still mounted when getting mfsnode.
* Add a reference to the mfsnode to prevent it disappearing in
* this routine.
*/
if ((error = vfs_busy(mp, NULL)) != 0)
return error;
vp = VFSTOUFS(mp)->um_devvp;
mfsp = VTOMFS(vp);
mutex_enter(&mfs_lock);
mfsp->mfs_refcnt++;
mutex_exit(&mfs_lock);
vfs_unbusy(mp, false, NULL);
base = mfsp->mfs_baseoff;
mutex_enter(&mfs_lock);
while (mfsp->mfs_shutdown != 1) {
while ((bp = BUFQ_GET(mfsp->mfs_buflist)) != NULL) {
mutex_exit(&mfs_lock);
mfs_doio(bp, base);
mutex_enter(&mfs_lock);
}
/*
* If a non-ignored signal is received, try to unmount.
* If that fails, or the filesystem is already in the
* process of being unmounted, clear the signal (it has been
* "processed"), otherwise we will loop here, as tsleep
* will always return EINTR/ERESTART.
*/
if (sleepreturn != 0) {
mutex_exit(&mfs_lock);
if (dounmount(mp, 0, curlwp) != 0) {
p = curproc;
ksiginfo_queue_init(&kq);
mutex_enter(p->p_lock);
sigclearall(p, NULL, &kq);
mutex_exit(p->p_lock);
ksiginfo_queue_drain(&kq);
}
sleepreturn = 0;
mutex_enter(&mfs_lock);
continue;
}
sleepreturn = cv_wait_sig(&mfsp->mfs_cv, &mfs_lock);
}
KASSERT(BUFQ_PEEK(mfsp->mfs_buflist) == NULL);
refcnt = --mfsp->mfs_refcnt;
mutex_exit(&mfs_lock);
if (refcnt == 0) {
bufq_free(mfsp->mfs_buflist);
cv_destroy(&mfsp->mfs_cv);
kmem_free(mfsp, sizeof(*mfsp));
}
return (sleepreturn);
}
/*
* Get file system statistics.
*/
int
mfs_statvfs(struct mount *mp, struct statvfs *sbp)
{
int error;
error = ffs_statvfs(mp, sbp);
if (error)
return error;
(void)strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name,
sizeof(sbp->f_fstypename));
sbp->f_fstypename[sizeof(sbp->f_fstypename) - 1] = '\0';
return 0;
}