svn commit: r213365 - in head/sys: conf kern
Marcel Moolenaar
marcel at FreeBSD.org
Sat Oct 2 19:44:13 UTC 2010
Author: marcel
Date: Sat Oct 2 19:44:13 2010
New Revision: 213365
URL: http://svn.freebsd.org/changeset/base/213365
Log:
Split the root mount logic from the (generic) mount code and move
it (the root mount code) into a new file called vfs_mountroot.c
The split is almost trivial, as the code is almost perfectly
non-intertwined. The only adjustment needed was to move the UMA
zone allocation out of vfs_mountroot() [in vfs_mountroot.c] and
into vfs_mount.c, where it had to be done as a SYSINIT [see
vfs_mount_init()].
There are no functional changes with this commit.
Added:
head/sys/kern/vfs_mountroot.c (contents, props changed)
Modified:
head/sys/conf/files
head/sys/kern/vfs_mount.c
Modified: head/sys/conf/files
==============================================================================
--- head/sys/conf/files Sat Oct 2 18:53:12 2010 (r213364)
+++ head/sys/conf/files Sat Oct 2 19:44:13 2010 (r213365)
@@ -2264,6 +2264,7 @@ kern/vfs_hash.c standard
kern/vfs_init.c standard
kern/vfs_lookup.c standard
kern/vfs_mount.c standard
+kern/vfs_mountroot.c standard
kern/vfs_subr.c standard
kern/vfs_syscalls.c standard
kern/vfs_vnops.c standard
Modified: head/sys/kern/vfs_mount.c
==============================================================================
--- head/sys/kern/vfs_mount.c Sat Oct 2 18:53:12 2010 (r213364)
+++ head/sys/kern/vfs_mount.c Sat Oct 2 19:44:13 2010 (r213365)
@@ -67,16 +67,10 @@ __FBSDID("$FreeBSD$");
#include <security/audit/audit.h>
#include <security/mac/mac_framework.h>
-#include "opt_rootdevname.h"
-
-#define ROOTNAME "root_device"
#define VFS_MOUNTARG_SIZE_MAX (1024 * 64)
-static void set_rootvnode(void);
static int vfs_domount(struct thread *td, const char *fstype,
char *fspath, int fsflags, void *fsdata);
-static int vfs_mountroot_ask(void);
-static int vfs_mountroot_try(const char *mountfrom, const char *options);
static void free_mntarg(struct mntarg *ma);
static int usermount = 0;
@@ -95,31 +89,6 @@ struct mtx mountlist_mtx;
MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF);
/*
- * The vnode of the system's root (/ in the filesystem, without chroot
- * active.)
- */
-struct vnode *rootvnode;
-
-/*
- * The root filesystem is detailed in the kernel environment variable
- * vfs.root.mountfrom, which is expected to be in the general format
- *
- * <vfsname>:[<path>][ <vfsname>:[<path>] ...]
- * vfsname := the name of a VFS known to the kernel and capable
- * of being mounted as root
- * path := disk device name or other data used by the filesystem
- * to locate its physical store
- *
- * If the environment variable vfs.root.mountfrom is a space separated list,
- * each list element is tried in turn and the root filesystem will be mounted
- * from the first one that suceeds.
- *
- * The environment variable vfs.root.mountfrom.options is a comma delimited
- * set of string mount options. These mount options must be parseable
- * by nmount() in the kernel.
- */
-
-/*
* Global opts, taken by all filesystems
*/
static const char *global_opts[] = {
@@ -133,21 +102,35 @@ static const char *global_opts[] = {
NULL
};
-/*
- * The root specifiers we will try if RB_CDROM is specified.
- */
-static char *cdrom_rootdevnames[] = {
- "cd9660:cd0",
- "cd9660:acd0",
- NULL
-};
+static int
+mount_init(void *mem, int size, int flags)
+{
+ struct mount *mp;
-/* legacy find-root code */
-char *rootdevnames[2] = {NULL, NULL};
-#ifndef ROOTDEVNAME
-# define ROOTDEVNAME NULL
-#endif
-static const char *ctrootdevname = ROOTDEVNAME;
+ mp = (struct mount *)mem;
+ mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
+ lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0);
+ return (0);
+}
+
+static void
+mount_fini(void *mem, int size)
+{
+ struct mount *mp;
+
+ mp = (struct mount *)mem;
+ lockdestroy(&mp->mnt_explock);
+ mtx_destroy(&mp->mnt_mtx);
+}
+
+static void
+vfs_mount_init(void *dummy __unused)
+{
+
+ mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), NULL,
+ NULL, mount_init, mount_fini, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
+}
+SYSINIT(vfs_mount, SI_SUB_VFS, SI_ORDER_ANY, vfs_mount_init, NULL);
/*
* ---------------------------------------------------------------------
@@ -452,27 +435,6 @@ vfs_rel(struct mount *mp)
MNT_IUNLOCK(mp);
}
-static int
-mount_init(void *mem, int size, int flags)
-{
- struct mount *mp;
-
- mp = (struct mount *)mem;
- mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
- lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0);
- return (0);
-}
-
-static void
-mount_fini(void *mem, int size)
-{
- struct mount *mp;
-
- mp = (struct mount *)mem;
- lockdestroy(&mp->mnt_explock);
- mtx_destroy(&mp->mnt_mtx);
-}
-
/*
* Allocate and initialize the mount point struct.
*/
@@ -1384,281 +1346,6 @@ dounmount(mp, flags, td)
}
/*
- * ---------------------------------------------------------------------
- * Mounting of root filesystem
- *
- */
-
-struct root_hold_token {
- const char *who;
- LIST_ENTRY(root_hold_token) list;
-};
-
-static LIST_HEAD(, root_hold_token) root_holds =
- LIST_HEAD_INITIALIZER(root_holds);
-
-static int root_mount_complete;
-
-/*
- * Hold root mount.
- */
-struct root_hold_token *
-root_mount_hold(const char *identifier)
-{
- struct root_hold_token *h;
-
- if (root_mounted())
- return (NULL);
-
- h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
- h->who = identifier;
- mtx_lock(&mountlist_mtx);
- LIST_INSERT_HEAD(&root_holds, h, list);
- mtx_unlock(&mountlist_mtx);
- return (h);
-}
-
-/*
- * Release root mount.
- */
-void
-root_mount_rel(struct root_hold_token *h)
-{
-
- if (h == NULL)
- return;
- mtx_lock(&mountlist_mtx);
- LIST_REMOVE(h, list);
- wakeup(&root_holds);
- mtx_unlock(&mountlist_mtx);
- free(h, M_DEVBUF);
-}
-
-/*
- * Wait for all subsystems to release root mount.
- */
-static void
-root_mount_prepare(void)
-{
- struct root_hold_token *h;
- struct timeval lastfail;
- int curfail = 0;
-
- for (;;) {
- DROP_GIANT();
- g_waitidle();
- PICKUP_GIANT();
- mtx_lock(&mountlist_mtx);
- if (LIST_EMPTY(&root_holds)) {
- mtx_unlock(&mountlist_mtx);
- break;
- }
- if (ppsratecheck(&lastfail, &curfail, 1)) {
- printf("Root mount waiting for:");
- LIST_FOREACH(h, &root_holds, list)
- printf(" %s", h->who);
- printf("\n");
- }
- msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold",
- hz);
- }
-}
-
-/*
- * Root was mounted, share the good news.
- */
-static void
-root_mount_done(void)
-{
-
- /* Keep prison0's root in sync with the global rootvnode. */
- mtx_lock(&prison0.pr_mtx);
- prison0.pr_root = rootvnode;
- vref(prison0.pr_root);
- mtx_unlock(&prison0.pr_mtx);
- /*
- * Use a mutex to prevent the wakeup being missed and waiting for
- * an extra 1 second sleep.
- */
- mtx_lock(&mountlist_mtx);
- root_mount_complete = 1;
- wakeup(&root_mount_complete);
- mtx_unlock(&mountlist_mtx);
-}
-
-/*
- * Return true if root is already mounted.
- */
-int
-root_mounted(void)
-{
-
- /* No mutex is acquired here because int stores are atomic. */
- return (root_mount_complete);
-}
-
-/*
- * Wait until root is mounted.
- */
-void
-root_mount_wait(void)
-{
-
- /*
- * Panic on an obvious deadlock - the function can't be called from
- * a thread which is doing the whole SYSINIT stuff.
- */
- KASSERT(curthread->td_proc->p_pid != 0,
- ("root_mount_wait: cannot be called from the swapper thread"));
- mtx_lock(&mountlist_mtx);
- while (!root_mount_complete) {
- msleep(&root_mount_complete, &mountlist_mtx, PZERO, "rootwait",
- hz);
- }
- mtx_unlock(&mountlist_mtx);
-}
-
-static void
-set_rootvnode()
-{
- struct proc *p;
-
- if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
- panic("Cannot find root vnode");
-
- VOP_UNLOCK(rootvnode, 0);
-
- p = curthread->td_proc;
- FILEDESC_XLOCK(p->p_fd);
-
- if (p->p_fd->fd_cdir != NULL)
- vrele(p->p_fd->fd_cdir);
- p->p_fd->fd_cdir = rootvnode;
- VREF(rootvnode);
-
- if (p->p_fd->fd_rdir != NULL)
- vrele(p->p_fd->fd_rdir);
- p->p_fd->fd_rdir = rootvnode;
- VREF(rootvnode);
-
- FILEDESC_XUNLOCK(p->p_fd);
-
- EVENTHANDLER_INVOKE(mountroot);
-}
-
-/*
- * Mount /devfs as our root filesystem, but do not put it on the mountlist
- * yet. Create a /dev -> / symlink so that absolute pathnames will lookup.
- */
-
-static void
-devfs_first(void)
-{
- struct thread *td = curthread;
- struct vfsoptlist *opts;
- struct vfsconf *vfsp;
- struct mount *mp = NULL;
- int error;
-
- vfsp = vfs_byname("devfs");
- KASSERT(vfsp != NULL, ("Could not find devfs by name"));
- if (vfsp == NULL)
- return;
-
- mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
-
- error = VFS_MOUNT(mp);
- KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
- if (error)
- return;
-
- opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
- TAILQ_INIT(opts);
- mp->mnt_opt = opts;
-
- mtx_lock(&mountlist_mtx);
- TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
- mtx_unlock(&mountlist_mtx);
-
- set_rootvnode();
-
- error = kern_symlink(td, "/", "dev", UIO_SYSSPACE);
- if (error)
- printf("kern_symlink /dev -> / returns %d\n", error);
-}
-
-/*
- * Surgically move our devfs to be mounted on /dev.
- */
-
-static void
-devfs_fixup(struct thread *td)
-{
- struct nameidata nd;
- struct vnode *vp, *dvp;
- struct mount *mp;
- int error;
-
- /* Remove our devfs mount from the mountlist and purge the cache */
- mtx_lock(&mountlist_mtx);
- mp = TAILQ_FIRST(&mountlist);
- TAILQ_REMOVE(&mountlist, mp, mnt_list);
- mtx_unlock(&mountlist_mtx);
- cache_purgevfs(mp);
-
- VFS_ROOT(mp, LK_EXCLUSIVE, &dvp);
- VI_LOCK(dvp);
- dvp->v_iflag &= ~VI_MOUNT;
- VI_UNLOCK(dvp);
- dvp->v_mountedhere = NULL;
-
- /* Set up the real rootvnode, and purge the cache */
- TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL;
- set_rootvnode();
- cache_purgevfs(rootvnode->v_mount);
-
- NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
- error = namei(&nd);
- if (error) {
- printf("Lookup of /dev for devfs, error: %d\n", error);
- vput(dvp);
- vfs_unbusy(mp);
- return;
- }
- NDFREE(&nd, NDF_ONLY_PNBUF);
- vp = nd.ni_vp;
- if (vp->v_type != VDIR) {
- printf("/dev is not a directory\n");
- vput(dvp);
- vput(vp);
- vfs_unbusy(mp);
- return;
- }
- error = vinvalbuf(vp, V_SAVE, 0, 0);
- if (error) {
- printf("vinvalbuf() of /dev failed, error: %d\n", error);
- vput(dvp);
- vput(vp);
- vfs_unbusy(mp);
- return;
- }
- cache_purge(vp);
- mp->mnt_vnodecovered = vp;
- vp->v_mountedhere = mp;
- mtx_lock(&mountlist_mtx);
- TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
- mtx_unlock(&mountlist_mtx);
- VOP_UNLOCK(vp, 0);
- vput(dvp);
- vfs_unbusy(mp);
-
- /* Unlink the no longer needed /dev/dev -> / symlink */
- error = kern_unlink(td, "/dev/dev", UIO_SYSSPACE);
- if (error)
- printf("kern_unlink of /dev/dev failed, error: %d\n", error);
-}
-
-/*
* Report errors during filesystem mounting.
*/
void
@@ -1695,288 +1382,6 @@ vfs_opterror(struct vfsoptlist *opts, co
}
/*
- * Find and mount the root filesystem
- */
-void
-vfs_mountroot(void)
-{
- char *cp, *cpt, *options, *tmpdev;
- int error, i, asked = 0;
-
- options = NULL;
-
- root_mount_prepare();
-
- mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount),
- NULL, NULL, mount_init, mount_fini,
- UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
- devfs_first();
-
- /*
- * We are booted with instructions to prompt for the root filesystem.
- */
- if (boothowto & RB_ASKNAME) {
- if (!vfs_mountroot_ask())
- goto mounted;
- asked = 1;
- }
-
- options = getenv("vfs.root.mountfrom.options");
-
- /*
- * The root filesystem information is compiled in, and we are
- * booted with instructions to use it.
- */
- if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) {
- if (!vfs_mountroot_try(ctrootdevname, options))
- goto mounted;
- ctrootdevname = NULL;
- }
-
- /*
- * We've been given the generic "use CDROM as root" flag. This is
- * necessary because one media may be used in many different
- * devices, so we need to search for them.
- */
- if (boothowto & RB_CDROM) {
- for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
- if (!vfs_mountroot_try(cdrom_rootdevnames[i], options))
- goto mounted;
- }
- }
-
- /*
- * Try to use the value read by the loader from /etc/fstab, or
- * supplied via some other means. This is the preferred
- * mechanism.
- */
- cp = getenv("vfs.root.mountfrom");
- if (cp != NULL) {
- cpt = cp;
- while ((tmpdev = strsep(&cpt, " \t")) != NULL) {
- error = vfs_mountroot_try(tmpdev, options);
- if (error == 0) {
- freeenv(cp);
- goto mounted;
- }
- }
- freeenv(cp);
- }
-
- /*
- * Try values that may have been computed by code during boot
- */
- if (!vfs_mountroot_try(rootdevnames[0], options))
- goto mounted;
- if (!vfs_mountroot_try(rootdevnames[1], options))
- goto mounted;
-
- /*
- * If we (still) have a compiled-in default, try it.
- */
- if (ctrootdevname != NULL)
- if (!vfs_mountroot_try(ctrootdevname, options))
- goto mounted;
- /*
- * Everything so far has failed, prompt on the console if we haven't
- * already tried that.
- */
- if (!asked)
- if (!vfs_mountroot_ask())
- goto mounted;
-
- panic("Root mount failed, startup aborted.");
-
-mounted:
- root_mount_done();
- freeenv(options);
-}
-
-static struct mntarg *
-parse_mountroot_options(struct mntarg *ma, const char *options)
-{
- char *p;
- char *name, *name_arg;
- char *val, *val_arg;
- char *opts;
-
- if (options == NULL || options[0] == '\0')
- return (ma);
-
- p = opts = strdup(options, M_MOUNT);
- if (opts == NULL) {
- return (ma);
- }
-
- while((name = strsep(&p, ",")) != NULL) {
- if (name[0] == '\0')
- break;
-
- val = strchr(name, '=');
- if (val != NULL) {
- *val = '\0';
- ++val;
- }
- if( strcmp(name, "rw") == 0 ||
- strcmp(name, "noro") == 0) {
- /*
- * The first time we mount the root file system,
- * we need to mount 'ro', so We need to ignore
- * 'rw' and 'noro' mount options.
- */
- continue;
- }
- name_arg = strdup(name, M_MOUNT);
- val_arg = NULL;
- if (val != NULL)
- val_arg = strdup(val, M_MOUNT);
-
- ma = mount_arg(ma, name_arg, val_arg,
- (val_arg != NULL ? -1 : 0));
- }
- free(opts, M_MOUNT);
- return (ma);
-}
-
-/*
- * Mount (mountfrom) as the root filesystem.
- */
-static int
-vfs_mountroot_try(const char *mountfrom, const char *options)
-{
- struct mount *mp;
- struct mntarg *ma;
- char *vfsname, *path;
- time_t timebase;
- int error;
- char patt[32];
- char errmsg[255];
-
- vfsname = NULL;
- path = NULL;
- mp = NULL;
- ma = NULL;
- error = EINVAL;
- bzero(errmsg, sizeof(errmsg));
-
- if (mountfrom == NULL)
- return (error); /* don't complain */
- printf("Trying to mount root from %s\n", mountfrom);
-
- /* parse vfs name and path */
- vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
- path = malloc(MNAMELEN, M_MOUNT, M_WAITOK);
- vfsname[0] = path[0] = 0;
- sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
- if (sscanf(mountfrom, patt, vfsname, path) < 1)
- goto out;
-
- if (path[0] == '\0')
- strcpy(path, ROOTNAME);
-
- ma = mount_arg(ma, "fstype", vfsname, -1);
- ma = mount_arg(ma, "fspath", "/", -1);
- ma = mount_arg(ma, "from", path, -1);
- ma = mount_arg(ma, "errmsg", errmsg, sizeof(errmsg));
- ma = mount_arg(ma, "ro", NULL, 0);
- ma = parse_mountroot_options(ma, options);
- error = kernel_mount(ma, MNT_ROOTFS);
-
- if (error == 0) {
- /*
- * We mount devfs prior to mounting the / FS, so the first
- * entry will typically be devfs.
- */
- mp = TAILQ_FIRST(&mountlist);
- KASSERT(mp != NULL, ("%s: mountlist is empty", __func__));
-
- /*
- * Iterate over all currently mounted file systems and use
- * the time stamp found to check and/or initialize the RTC.
- * Typically devfs has no time stamp and the only other FS
- * is the actual / FS.
- * Call inittodr() only once and pass it the largest of the
- * timestamps we encounter.
- */
- timebase = 0;
- do {
- if (mp->mnt_time > timebase)
- timebase = mp->mnt_time;
- mp = TAILQ_NEXT(mp, mnt_list);
- } while (mp != NULL);
- inittodr(timebase);
-
- devfs_fixup(curthread);
- }
-
- if (error != 0 ) {
- printf("ROOT MOUNT ERROR: %s\n", errmsg);
- printf("If you have invalid mount options, reboot, and ");
- printf("first try the following from\n");
- printf("the loader prompt:\n\n");
- printf(" set vfs.root.mountfrom.options=rw\n\n");
- printf("and then remove invalid mount options from ");
- printf("/etc/fstab.\n\n");
- }
-out:
- free(path, M_MOUNT);
- free(vfsname, M_MOUNT);
- return (error);
-}
-
-/*
- * ---------------------------------------------------------------------
- * Interactive root filesystem selection code.
- */
-
-static int
-vfs_mountroot_ask(void)
-{
- char name[128];
- char *mountfrom;
- char *options;
-
- for(;;) {
- printf("Loader variables:\n");
- printf("vfs.root.mountfrom=");
- mountfrom = getenv("vfs.root.mountfrom");
- if (mountfrom != NULL) {
- printf("%s", mountfrom);
- }
- printf("\n");
- printf("vfs.root.mountfrom.options=");
- options = getenv("vfs.root.mountfrom.options");
- if (options != NULL) {
- printf("%s", options);
- }
- printf("\n");
- freeenv(mountfrom);
- freeenv(options);
- printf("\nManual root filesystem specification:\n");
- printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n");
- printf(" eg. zfs:tank\n");
- printf(" eg. ufs:/dev/da0s1a\n");
- printf(" eg. cd9660:/dev/acd0\n");
- printf(" This is equivalent to: ");
- printf("mount -t cd9660 /dev/acd0 /\n");
- printf("\n");
- printf(" ? List valid disk boot devices\n");
- printf(" <empty line> Abort manual input\n");
- printf("\nmountroot> ");
- gets(name, sizeof(name), 1);
- if (name[0] == '\0')
- return (1);
- if (name[0] == '?') {
- printf("\nList of GEOM managed disk devices:\n ");
- g_dev_print();
- continue;
- }
- if (!vfs_mountroot_try(name, NULL))
- return (0);
- }
-}
-
-/*
* ---------------------------------------------------------------------
* Functions for querying mount options/arguments from filesystems.
*/
Added: head/sys/kern/vfs_mountroot.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/sys/kern/vfs_mountroot.c Sat Oct 2 19:44:13 2010 (r213365)
@@ -0,0 +1,626 @@
+/*-
+ * Copyright (c) 1999-2004 Poul-Henning Kamp
+ * Copyright (c) 1999 Michael Smith
+ * Copyright (c) 1989, 1993
+ * The Regents of the University of California. All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * 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.
+ * 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 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/conf.h>
+#include <sys/fcntl.h>
+#include <sys/jail.h>
+#include <sys/kernel.h>
+#include <sys/libkern.h>
+#include <sys/malloc.h>
+#include <sys/mount.h>
+#include <sys/mutex.h>
+#include <sys/namei.h>
+#include <sys/priv.h>
+#include <sys/proc.h>
+#include <sys/filedesc.h>
+#include <sys/reboot.h>
+#include <sys/syscallsubr.h>
+#include <sys/sysproto.h>
+#include <sys/sx.h>
+#include <sys/sysctl.h>
+#include <sys/sysent.h>
+#include <sys/systm.h>
+#include <sys/vnode.h>
+#include <vm/uma.h>
+
+#include <geom/geom.h>
+
+#include <machine/stdarg.h>
+
+#include "opt_rootdevname.h"
+
+#define ROOTNAME "root_device"
+
+static int vfs_mountroot_ask(void);
+static int vfs_mountroot_try(const char *mountfrom, const char *options);
+
+/*
+ * The vnode of the system's root (/ in the filesystem, without chroot
+ * active.)
+ */
+struct vnode *rootvnode;
+
+/*
+ * The root filesystem is detailed in the kernel environment variable
+ * vfs.root.mountfrom, which is expected to be in the general format
+ *
+ * <vfsname>:[<path>][ <vfsname>:[<path>] ...]
+ * vfsname := the name of a VFS known to the kernel and capable
+ * of being mounted as root
+ * path := disk device name or other data used by the filesystem
+ * to locate its physical store
+ *
+ * If the environment variable vfs.root.mountfrom is a space separated list,
+ * each list element is tried in turn and the root filesystem will be mounted
+ * from the first one that suceeds.
+ *
+ * The environment variable vfs.root.mountfrom.options is a comma delimited
+ * set of string mount options. These mount options must be parseable
+ * by nmount() in the kernel.
+ */
+
+/*
+ * The root specifiers we will try if RB_CDROM is specified.
+ */
+static char *cdrom_rootdevnames[] = {
+ "cd9660:cd0",
+ "cd9660:acd0",
+ NULL
+};
+
+/* legacy find-root code */
+char *rootdevnames[2] = {NULL, NULL};
+#ifndef ROOTDEVNAME
+# define ROOTDEVNAME NULL
+#endif
+static const char *ctrootdevname = ROOTDEVNAME;
+
+struct root_hold_token {
+ const char *who;
+ LIST_ENTRY(root_hold_token) list;
+};
+
+static LIST_HEAD(, root_hold_token) root_holds =
+ LIST_HEAD_INITIALIZER(root_holds);
+
+static int root_mount_complete;
+
+struct root_hold_token *
+root_mount_hold(const char *identifier)
+{
+ struct root_hold_token *h;
+
+ if (root_mounted())
+ return (NULL);
+
+ h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
+ h->who = identifier;
+ mtx_lock(&mountlist_mtx);
+ LIST_INSERT_HEAD(&root_holds, h, list);
+ mtx_unlock(&mountlist_mtx);
+ return (h);
+}
+
+void
+root_mount_rel(struct root_hold_token *h)
+{
+
+ if (h == NULL)
+ return;
+ mtx_lock(&mountlist_mtx);
+ LIST_REMOVE(h, list);
+ wakeup(&root_holds);
+ mtx_unlock(&mountlist_mtx);
+ free(h, M_DEVBUF);
+}
+
+static void
+root_mount_prepare(void)
+{
+ struct root_hold_token *h;
+ struct timeval lastfail;
+ int curfail = 0;
+
+ for (;;) {
+ DROP_GIANT();
+ g_waitidle();
+ PICKUP_GIANT();
+ mtx_lock(&mountlist_mtx);
+ if (LIST_EMPTY(&root_holds)) {
+ mtx_unlock(&mountlist_mtx);
+ break;
+ }
+ if (ppsratecheck(&lastfail, &curfail, 1)) {
+ printf("Root mount waiting for:");
+ LIST_FOREACH(h, &root_holds, list)
+ printf(" %s", h->who);
+ printf("\n");
+ }
+ msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold",
+ hz);
+ }
+}
+
+static void
+root_mount_done(void)
+{
+
+ /* Keep prison0's root in sync with the global rootvnode. */
+ mtx_lock(&prison0.pr_mtx);
+ prison0.pr_root = rootvnode;
+ vref(prison0.pr_root);
+ mtx_unlock(&prison0.pr_mtx);
+ /*
+ * Use a mutex to prevent the wakeup being missed and waiting for
+ * an extra 1 second sleep.
+ */
+ mtx_lock(&mountlist_mtx);
+ root_mount_complete = 1;
+ wakeup(&root_mount_complete);
+ mtx_unlock(&mountlist_mtx);
+}
+
+int
+root_mounted(void)
+{
+
+ /* No mutex is acquired here because int stores are atomic. */
+ return (root_mount_complete);
+}
+
+void
+root_mount_wait(void)
+{
+
+ /*
+ * Panic on an obvious deadlock - the function can't be called from
+ * a thread which is doing the whole SYSINIT stuff.
+ */
+ KASSERT(curthread->td_proc->p_pid != 0,
+ ("root_mount_wait: cannot be called from the swapper thread"));
+ mtx_lock(&mountlist_mtx);
+ while (!root_mount_complete) {
+ msleep(&root_mount_complete, &mountlist_mtx, PZERO, "rootwait",
+ hz);
+ }
+ mtx_unlock(&mountlist_mtx);
+}
+
+static void
+set_rootvnode(void)
+{
+ struct proc *p;
+
+ if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
+ panic("Cannot find root vnode");
+
+ VOP_UNLOCK(rootvnode, 0);
+
+ p = curthread->td_proc;
+ FILEDESC_XLOCK(p->p_fd);
+
+ if (p->p_fd->fd_cdir != NULL)
+ vrele(p->p_fd->fd_cdir);
+ p->p_fd->fd_cdir = rootvnode;
+ VREF(rootvnode);
+
+ if (p->p_fd->fd_rdir != NULL)
+ vrele(p->p_fd->fd_rdir);
+ p->p_fd->fd_rdir = rootvnode;
+ VREF(rootvnode);
+
+ FILEDESC_XUNLOCK(p->p_fd);
+
+ EVENTHANDLER_INVOKE(mountroot);
+}
+
+static void
+devfs_first(void)
+{
+ struct thread *td = curthread;
+ struct vfsoptlist *opts;
+ struct vfsconf *vfsp;
+ struct mount *mp = NULL;
+ int error;
+
+ vfsp = vfs_byname("devfs");
+ KASSERT(vfsp != NULL, ("Could not find devfs by name"));
+ if (vfsp == NULL)
+ return;
+
+ mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
+
+ error = VFS_MOUNT(mp);
+ KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
+ if (error)
+ return;
+
+ opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
+ TAILQ_INIT(opts);
+ mp->mnt_opt = opts;
+
+ mtx_lock(&mountlist_mtx);
+ TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
+ mtx_unlock(&mountlist_mtx);
+
+ set_rootvnode();
+
+ error = kern_symlink(td, "/", "dev", UIO_SYSSPACE);
+ if (error)
+ printf("kern_symlink /dev -> / returns %d\n", error);
*** DIFF OUTPUT TRUNCATED AT 1000 LINES ***
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