freebsd-skq/sys/ufs/mfs/mfs_vfsops.c
msmith 219fe6842a Make MFS work with the new root filesystem search process.
In order to achieve this, root filesystem mount is moved from
SI_ORDER_FIRST to SI_ORDER_SECOND in the SI_SUB_MOUNT_ROOT sysinit
group.  Now, modules which wish to usurp the default root mount
can use SI_ORDER_FIRST.

A compiled-in or preloaded MFS filesystem will become the root
filesystem unless the vfs.root.mountfrom environment variable refers
to a valid bootable device.  This will normally only be the case when
the kernel and MFS image have been loaded from a disk which has a
valid /etc/fstab file.  In this case, the variable should be manually
overridden in the loader, or the kernel booted with -a.  In either
case "mfs:" should be supplied as the new value.

Also fix a typo in one DFLTROOT case that would not have compiled.
1999-11-03 11:02:47 +00:00

521 lines
13 KiB
C

/*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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
* $FreeBSD$
*/
#include "opt_mfs.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/mount.h>
#include <sys/signalvar.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/linker.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>
MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part");
#ifdef MFS_ROOT
static caddr_t mfs_rootbase; /* address of mini-root in kernel virtual memory */
static u_long mfs_rootsize; /* size of mini-root in bytes */
#endif
static int mfs_minor; /* used for building internal dev_t */
extern vop_t **mfs_vnodeop_p;
static int mfs_mount __P((struct mount *mp,
char *path, caddr_t data, struct nameidata *ndp,
struct proc *p));
static int mfs_start __P((struct mount *mp, int flags, struct proc *p));
static int mfs_statfs __P((struct mount *mp, struct statfs *sbp,
struct proc *p));
static int mfs_init __P((struct vfsconf *));
static void mfs_takeroot __P((void *));
static struct cdevsw mfs_cdevsw = {
/* open */ noopen,
/* close */ noclose,
/* read */ physread,
/* write */ physwrite,
/* ioctl */ noioctl,
/* poll */ nopoll,
/* mmap */ nommap,
/* strategy */ nostrategy,
/* name */ "MFS",
/* maj */ 253,
/* dump */ nodump,
/* psize */ nopsize,
/* flags */ D_DISK,
/* bmaj */ 253,
};
/*
* mfs vfs operations.
*/
static struct vfsops mfs_vfsops = {
mfs_mount,
mfs_start,
ffs_unmount,
ufs_root,
ufs_quotactl,
mfs_statfs,
ffs_sync,
ffs_vget,
ffs_fhtovp,
ufs_check_export,
ffs_vptofh,
mfs_init,
};
VFS_SET(mfs_vfsops, mfs, 0);
#ifdef MFS_ROOT
#ifdef MFS_ROOT_SIZE
/* Image was already written into mfs_root */
static u_char mfs_root[MFS_ROOT_SIZE*1024] = "MFS Filesystem goes here";
static u_char end_mfs_root[] __unused = "MFS Filesystem had better STOP here";
#endif
u_char *
mfs_getimage(void)
{
#ifdef MFS_ROOT_SIZE
/* Get it from compiled-in code */
return mfs_root;
#else
caddr_t p;
vm_offset_t *q;
p = preload_search_by_type("mfs_root");
if (!p)
return NULL;
q = (vm_offset_t *)preload_search_info(p, MODINFO_ADDR);
if (!q)
return NULL;
return (u_char *)*q;
#endif
}
#endif /* MFS_ROOT */
/*
* mfs_mount
*
* Called when mounting local physical media
*
* PARAMETERS:
* mountroot
* mp mount point structure
* path NULL (flag for root mount!!!)
* data <unused>
* ndp <unused>
* p process (user credentials check [statfs])
*
* mount
* mp mount point structure
* path path to mount point
* data pointer to argument struct in user space
* ndp mount point namei() return (used for
* credentials on reload), reused to look
* up block device.
* p process (user credentials check)
*
* RETURNS: 0 Success
* !0 error number (errno.h)
*
* LOCK STATE:
*
* ENTRY
* mount point is locked
* EXIT
* mount point is locked
*
* NOTES:
* A NULL path can be used for a flag since the mount
* system call will fail with EFAULT in copyinstr in
* namei() if it is a genuine NULL from the user.
*/
/* ARGSUSED */
static int
mfs_mount(mp, path, data, ndp, p)
register struct mount *mp;
char *path;
caddr_t data;
struct nameidata *ndp;
struct proc *p;
{
struct vnode *devvp;
struct mfs_args args;
struct ufsmount *ump;
struct fs *fs;
#ifdef MFS_ROOT
u_char *base;
#endif
struct mfsnode *mfsp;
size_t size;
int flags, err;
dev_t dev;
/*
* Use NULL path to flag a root mount
*/
if( path == NULL) {
/*
***
* Mounting root file system
***
*/
#ifdef MFS_ROOT
/* Get it from preload area */
base = mfs_getimage();
if (!base)
panic("No mfs_root image loaded; can't continue!");
fs = (struct fs *)(base + SBOFF);
/* check for valid super block */
if (fs->fs_magic != FS_MAGIC || fs->fs_bsize > MAXBSIZE ||
fs->fs_bsize < sizeof(struct fs)) {
panic("MFS image is invalid!!");
}
mfs_rootbase = base;
mfs_rootsize = fs->fs_fsize * fs->fs_size;
/* remake rootdev, since vfs_mountroot will have it wrong */
rootdev = make_dev(&mfs_cdevsw, mfs_minor,
0, 0, 0, "MFS%d", mfs_minor);
rootdev->si_bsize_phys = DEV_BSIZE;
rootdev->si_iosize_max = DFLTPHYS;
mfs_minor++;
if ((err = bdevvp(rootdev, &rootvp))) {
printf("mfs_mount: can't find rootvp\n");
return (err);
}
/*
* FS specific handling
*/
MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK);
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_pid = p->p_pid;
mfsp->mfs_active = 1;
bufq_init(&mfsp->buf_queue);
/* MFS wants to be read/write */
mp->mnt_flag &= ~MNT_RDONLY;
/*
* Attempt mount
*/
if( (err = ffs_mountfs(rootvp, mp, p, M_MFSNODE)) != 0 ) {
/* fs specific cleanup (if any)*/
rootvp->v_data = NULL;
FREE(mfsp, M_MFSNODE);
goto error_1;
}
goto dostatfs; /* success*/
#else /* !MFS_ROOT */
/* you loose */
panic("mfs_mount: mount MFS as root: not configured!");
#endif /* MFS_ROOT */
}
/*
***
* Mounting non-root file system or updating a file system
***
*/
/* copy in user arguments*/
if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0)
goto error_1;
/*
* 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) {
/*
********************
* 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;
err = ffs_flushfiles(mp, flags, p);
if (err)
goto error_1;
}
if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR))
fs->fs_ronly = 0;
/* if not updating name...*/
if (args.fspec == 0) {
/*
* Process export requests. Jumping to "success"
* will return the vfs_export() error code.
*/
err = vfs_export(mp, &ump->um_export, &args.export);
goto success;
}
/* XXX MFS does not support name updating*/
goto success;
}
/*
* Do the MALLOC before the getnewvnode since doing so afterward
* might cause a bogus v_data pointer to get dereferenced
* elsewhere if MALLOC should block.
*/
MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK);
err = getnewvnode(VT_MFS, (struct mount *)0, mfs_vnodeop_p, &devvp);
if (err) {
FREE(mfsp, M_MFSNODE);
goto error_1;
}
devvp->v_type = VBLK;
dev = make_dev(&mfs_cdevsw, mfs_minor, 0, 0, 0, "MFS%d", mfs_minor);
/* It is not clear that these will get initialized otherwise */
dev->si_bsize_phys = DEV_BSIZE;
dev->si_iosize_max = DFLTPHYS;
addaliasu(devvp, makeudev(253, mfs_minor++));
devvp->v_data = mfsp;
mfsp->mfs_baseoff = args.base;
mfsp->mfs_size = args.size;
mfsp->mfs_vnode = devvp;
mfsp->mfs_pid = p->p_pid;
mfsp->mfs_active = 1;
bufq_init(&mfsp->buf_queue);
/*
* Since this is a new mount, we want the names for
* the device and the mount point copied in. If an
* error occurs, the mountpoint is discarded by the
* upper level code.
*/
/* Save "last mounted on" info for mount point (NULL pad)*/
copyinstr( path, /* mount point*/
mp->mnt_stat.f_mntonname, /* save area*/
MNAMELEN - 1, /* max size*/
&size); /* real size*/
bzero( mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
/* Save "mounted from" info for mount point (NULL pad)*/
copyinstr( args.fspec, /* device name*/
mp->mnt_stat.f_mntfromname, /* save area*/
MNAMELEN - 1, /* max size*/
&size); /* real size*/
bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
if ((err = ffs_mountfs(devvp, mp, p, M_MFSNODE)) != 0) {
mfsp->mfs_active = 0;
goto error_2;
}
#ifdef MFS_ROOT
dostatfs:
#endif
/*
* Initialize FS stat information in mount struct; uses both
* mp->mnt_stat.f_mntonname and mp->mnt_stat.f_mntfromname
*
* This code is common to root and non-root mounts
*/
(void) VFS_STATFS(mp, &mp->mnt_stat, p);
goto success;
error_2: /* error with devvp held*/
/* release devvp before failing*/
vrele(devvp);
error_1: /* no state to back out*/
success:
return( err);
}
static int mfs_pri = PWAIT | PCATCH; /* XXX prob. temp */
/*
* 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 */
static int
mfs_start(mp, flags, p)
struct mount *mp;
int flags;
struct proc *p;
{
register struct vnode *vp = VFSTOUFS(mp)->um_devvp;
register struct mfsnode *mfsp = VTOMFS(vp);
register struct buf *bp;
register int gotsig = 0, sig;
/*
* We must prevent the system from trying to swap
* out or kill ( when swap space is low, see vm/pageout.c ) the
* process. A deadlock can occur if the process is swapped out,
* and the system can loop trying to kill the unkillable ( while
* references exist ) MFS process when swap space is low.
*/
PHOLD(curproc);
while (mfsp->mfs_active) {
int s;
s = splbio();
while ((bp = bufq_first(&mfsp->buf_queue)) != NULL) {
bufq_remove(&mfsp->buf_queue, bp);
splx(s);
mfs_doio(bp, mfsp);
wakeup((caddr_t)bp);
s = splbio();
}
splx(s);
/*
* If a non-ignored signal is received, try to unmount.
* If that fails, clear the signal (it has been "processed"),
* otherwise we will loop here, as tsleep will always return
* EINTR/ERESTART.
*/
/*
* Note that dounmount() may fail if work was queued after
* we slept. We have to jump hoops here to make sure that we
* process any buffers after the sleep, before we dounmount()
*/
if (gotsig) {
gotsig = 0;
if (dounmount(mp, 0, p) != 0) {
sig = CURSIG(p);
if (sig)
SIGDELSET(p->p_siglist, sig);
}
}
else if (tsleep((caddr_t)vp, mfs_pri, "mfsidl", 0))
gotsig++; /* try to unmount in next pass */
}
return (0);
}
/*
* Get file system statistics.
*/
static int
mfs_statfs(mp, sbp, p)
struct mount *mp;
struct statfs *sbp;
struct proc *p;
{
int error;
error = ffs_statfs(mp, sbp, p);
sbp->f_type = mp->mnt_vfc->vfc_typenum;
return (error);
}
/*
* Memory based filesystem initialization.
*/
static int
mfs_init(vfsp)
struct vfsconf *vfsp;
{
cdevsw_add(&mfs_cdevsw);
return (0);
}
#ifdef MFS_ROOT
/*
* Just before root is mounted, check to see if we are a candidate
* to supply it. If we have an image available, override the guessed
* defaults.
*/
static void
mfs_takeroot(junk)
void *junk;
{
if (bootverbose)
printf("Considering MFS root f/s...");
if (mfs_getimage()) {
rootdevnames[0] = "mfs:";
printf("preloaded filesystem found.\n");
} else if (bootverbose) {
printf("not found.\n");
}
}
SYSINIT(mfs_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, mfs_takeroot, NULL);
#endif