[linux-2.6-block.git] / init / do_mounts.c

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include <linux/fd.h>
#include <linux/tty.h>
#include <linux/suspend.h>
#include <linux/root_dev.h>
#include <linux/security.h>
#include <linux/delay.h>
#include <linux/mount.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/initrd.h>
#include <linux/async.h>
#include <linux/fs_struct.h>
#include <linux/slab.h>
#include <linux/ramfs.h>
#include <linux/shmem_fs.h>
#include <linux/ktime.h>

#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/nfs_mount.h>
#include <linux/raid/detect.h>
#include <uapi/linux/mount.h>

#include "do_mounts.h"

int root_mountflags = MS_RDONLY | MS_SILENT;
static char __initdata saved_root_name[64];
static int root_wait;

dev_t ROOT_DEV;

static int __init load_ramdisk(char *str)
{
	pr_warn("ignoring the deprecated load_ramdisk= option\n");
	return 1;
}
__setup("load_ramdisk=", load_ramdisk);

static int __init readonly(char *str)
{
	if (*str)
		return 0;
	root_mountflags |= MS_RDONLY;
	return 1;
}

static int __init readwrite(char *str)
{
	if (*str)
		return 0;
	root_mountflags &= ~MS_RDONLY;
	return 1;
}

__setup("ro", readonly);
__setup("rw", readwrite);

static int __init root_dev_setup(char *line)
{
	strscpy(saved_root_name, line, sizeof(saved_root_name));
	return 1;
}

__setup("root=", root_dev_setup);

static int __init rootwait_setup(char *str)
{
	if (*str)
		return 0;
	root_wait = -1;
	return 1;
}

__setup("rootwait", rootwait_setup);

static int __init rootwait_timeout_setup(char *str)
{
	int sec;

	if (kstrtoint(str, 0, &sec) || sec < 0) {
		pr_warn("ignoring invalid rootwait value\n");
		goto ignore;
	}

	if (check_mul_overflow(sec, MSEC_PER_SEC, &root_wait)) {
		pr_warn("ignoring excessive rootwait value\n");
		goto ignore;
	}

	return 1;

ignore:
	/* Fallback to indefinite wait */
	root_wait = -1;

	return 1;
}

__setup("rootwait=", rootwait_timeout_setup);

static char * __initdata root_mount_data;
static int __init root_data_setup(char *str)
{
	root_mount_data = str;
	return 1;
}

static char * __initdata root_fs_names;
static int __init fs_names_setup(char *str)
{
	root_fs_names = str;
	return 1;
}

static unsigned int __initdata root_delay;
static int __init root_delay_setup(char *str)
{
	root_delay = simple_strtoul(str, NULL, 0);
	return 1;
}

__setup("rootflags=", root_data_setup);
__setup("rootfstype=", fs_names_setup);
__setup("rootdelay=", root_delay_setup);

/* This can return zero length strings. Caller should check */
static int __init split_fs_names(char *page, size_t size)
{
	int count = 1;
	char *p = page;

	strscpy(p, root_fs_names, size);
	while (*p++) {
		if (p[-1] == ',') {
			p[-1] = '\0';
			count++;
		}
	}

	return count;
}

static int __init do_mount_root(const char *name, const char *fs,
				 const int flags, const void *data)
{
	struct super_block *s;
	struct page *p = NULL;
	char *data_page = NULL;
	int ret;

	if (data) {
		/* init_mount() requires a full page as fifth argument */
		p = alloc_page(GFP_KERNEL);
		if (!p)
			return -ENOMEM;
		data_page = page_address(p);
		strscpy_pad(data_page, data, PAGE_SIZE);
	}

	ret = init_mount(name, "/root", fs, flags, data_page);
	if (ret)
		goto out;

	init_chdir("/root");
	s = current->fs->pwd.dentry->d_sb;
	ROOT_DEV = s->s_dev;
	printk(KERN_INFO
	       "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
	       s->s_type->name,
	       sb_rdonly(s) ? " readonly" : "",
	       MAJOR(ROOT_DEV), MINOR(ROOT_DEV));

out:
	if (p)
		put_page(p);
	return ret;
}

void __init mount_root_generic(char *name, char *pretty_name, int flags)
{
	struct page *page = alloc_page(GFP_KERNEL);
	char *fs_names = page_address(page);
	char *p;
	char b[BDEVNAME_SIZE];
	int num_fs, i;

	scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)",
		  MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
	if (root_fs_names)
		num_fs = split_fs_names(fs_names, PAGE_SIZE);
	else
		num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
retry:
	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) {
		int err;

		if (!*p)
			continue;
		err = do_mount_root(name, p, flags, root_mount_data);
		switch (err) {
			case 0:
				goto out;
			case -EACCES:
			case -EINVAL:
#ifdef CONFIG_BLOCK
				init_flush_fput();
#endif
				continue;
		}
	        /*
		 * Allow the user to distinguish between failed sys_open
		 * and bad superblock on root device.
		 * and give them a list of the available devices
		 */
		printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
				pretty_name, b, err);
		printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
		printk_all_partitions();

		if (root_fs_names)
			num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
		if (!num_fs)
			pr_err("Can't find any bdev filesystem to be used for mount!\n");
		else {
			pr_err("List of all bdev filesystems:\n");
			for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
				pr_err(" %s", p);
			pr_err("\n");
		}

		panic("VFS: Unable to mount root fs on %s", b);
	}
	if (!(flags & SB_RDONLY)) {
		flags |= SB_RDONLY;
		goto retry;
	}

	printk("List of all partitions:\n");
	printk_all_partitions();
	printk("No filesystem could mount root, tried: ");
	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
		printk(" %s", p);
	printk("\n");
	panic("VFS: Unable to mount root fs on \"%s\" or %s", pretty_name, b);
out:
	put_page(page);
}
 
#ifdef CONFIG_ROOT_NFS

#define NFSROOT_TIMEOUT_MIN	5
#define NFSROOT_TIMEOUT_MAX	30
#define NFSROOT_RETRY_MAX	5

static void __init mount_nfs_root(void)
{
	char *root_dev, *root_data;
	unsigned int timeout;
	int try;

	if (nfs_root_data(&root_dev, &root_data))
		goto fail;

	/*
	 * The server or network may not be ready, so try several
	 * times.  Stop after a few tries in case the client wants
	 * to fall back to other boot methods.
	 */
	timeout = NFSROOT_TIMEOUT_MIN;
	for (try = 1; ; try++) {
		if (!do_mount_root(root_dev, "nfs", root_mountflags, root_data))
			return;
		if (try > NFSROOT_RETRY_MAX)
			break;

		/* Wait, in case the server refused us immediately */
		ssleep(timeout);
		timeout <<= 1;
		if (timeout > NFSROOT_TIMEOUT_MAX)
			timeout = NFSROOT_TIMEOUT_MAX;
	}
fail:
	pr_err("VFS: Unable to mount root fs via NFS.\n");
}
#else
static inline void mount_nfs_root(void)
{
}
#endif /* CONFIG_ROOT_NFS */

#ifdef CONFIG_CIFS_ROOT

#define CIFSROOT_TIMEOUT_MIN	5
#define CIFSROOT_TIMEOUT_MAX	30
#define CIFSROOT_RETRY_MAX	5

static void __init mount_cifs_root(void)
{
	char *root_dev, *root_data;
	unsigned int timeout;
	int try;

	if (cifs_root_data(&root_dev, &root_data))
		goto fail;

	timeout = CIFSROOT_TIMEOUT_MIN;
	for (try = 1; ; try++) {
		if (!do_mount_root(root_dev, "cifs", root_mountflags,
				   root_data))
			return;
		if (try > CIFSROOT_RETRY_MAX)
			break;

		ssleep(timeout);
		timeout <<= 1;
		if (timeout > CIFSROOT_TIMEOUT_MAX)
			timeout = CIFSROOT_TIMEOUT_MAX;
	}
fail:
	pr_err("VFS: Unable to mount root fs via SMB.\n");
}
#else
static inline void mount_cifs_root(void)
{
}
#endif /* CONFIG_CIFS_ROOT */

static bool __init fs_is_nodev(char *fstype)
{
	struct file_system_type *fs = get_fs_type(fstype);
	bool ret = false;

	if (fs) {
		ret = !(fs->fs_flags & FS_REQUIRES_DEV);
		put_filesystem(fs);
	}

	return ret;
}

static int __init mount_nodev_root(char *root_device_name)
{
	char *fs_names, *fstype;
	int err = -EINVAL;
	int num_fs, i;

	fs_names = (void *)__get_free_page(GFP_KERNEL);
	if (!fs_names)
		return -EINVAL;
	num_fs = split_fs_names(fs_names, PAGE_SIZE);

	for (i = 0, fstype = fs_names; i < num_fs;
	     i++, fstype += strlen(fstype) + 1) {
		if (!*fstype)
			continue;
		if (!fs_is_nodev(fstype))
			continue;
		err = do_mount_root(root_device_name, fstype, root_mountflags,
				    root_mount_data);
		if (!err)
			break;
	}

	free_page((unsigned long)fs_names);
	return err;
}

#ifdef CONFIG_BLOCK
static void __init mount_block_root(char *root_device_name)
{
	int err = create_dev("/dev/root", ROOT_DEV);

	if (err < 0)
		pr_emerg("Failed to create /dev/root: %d\n", err);
	mount_root_generic("/dev/root", root_device_name, root_mountflags);
}
#else
static inline void mount_block_root(char *root_device_name)
{
}
#endif /* CONFIG_BLOCK */

void __init mount_root(char *root_device_name)
{
	switch (ROOT_DEV) {
	case Root_NFS:
		mount_nfs_root();
		break;
	case Root_CIFS:
		mount_cifs_root();
		break;
	case Root_Generic:
		mount_root_generic(root_device_name, root_device_name,
				   root_mountflags);
		break;
	case 0:
		if (root_device_name && root_fs_names &&
		    mount_nodev_root(root_device_name) == 0)
			break;
		fallthrough;
	default:
		mount_block_root(root_device_name);
		break;
	}
}

/* wait for any asynchronous scanning to complete */
static void __init wait_for_root(char *root_device_name)
{
	ktime_t end;

	if (ROOT_DEV != 0)
		return;

	pr_info("Waiting for root device %s...\n", root_device_name);

	end = ktime_add_ms(ktime_get_raw(), root_wait);

	while (!driver_probe_done() ||
	       early_lookup_bdev(root_device_name, &ROOT_DEV) < 0) {
		msleep(5);
		if (root_wait > 0 && ktime_after(ktime_get_raw(), end))
			break;
	}

	async_synchronize_full();

}

static dev_t __init parse_root_device(char *root_device_name)
{
	int error;
	dev_t dev;

	if (!strncmp(root_device_name, "mtd", 3) ||
	    !strncmp(root_device_name, "ubi", 3))
		return Root_Generic;
	if (strcmp(root_device_name, "/dev/nfs") == 0)
		return Root_NFS;
	if (strcmp(root_device_name, "/dev/cifs") == 0)
		return Root_CIFS;
	if (strcmp(root_device_name, "/dev/ram") == 0)
		return Root_RAM0;

	error = early_lookup_bdev(root_device_name, &dev);
	if (error) {
		if (error == -EINVAL && root_wait) {
			pr_err("Disabling rootwait; root= is invalid.\n");
			root_wait = 0;
		}
		return 0;
	}
	return dev;
}

/*
 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
 */
void __init prepare_namespace(void)
{
	if (root_delay) {
		printk(KERN_INFO "Waiting %d sec before mounting root device...\n",
		       root_delay);
		ssleep(root_delay);
	}

	/*
	 * wait for the known devices to complete their probing
	 *
	 * Note: this is a potential source of long boot delays.
	 * For example, it is not atypical to wait 5 seconds here
	 * for the touchpad of a laptop to initialize.
	 */
	wait_for_device_probe();

	md_run_setup();

	if (saved_root_name[0])
		ROOT_DEV = parse_root_device(saved_root_name);

	if (initrd_load(saved_root_name))
		goto out;

	if (root_wait)
		wait_for_root(saved_root_name);
	mount_root(saved_root_name);
out:
	devtmpfs_mount();
	init_mount(".", "/", NULL, MS_MOVE, NULL);
	init_chroot(".");
}

static bool is_tmpfs;
static int rootfs_init_fs_context(struct fs_context *fc)
{
	if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
		return shmem_init_fs_context(fc);

	return ramfs_init_fs_context(fc);
}

struct file_system_type rootfs_fs_type = {
	.name		= "rootfs",
	.init_fs_context = rootfs_init_fs_context,
	.kill_sb	= kill_litter_super,
};

void __init init_rootfs(void)
{
	if (IS_ENABLED(CONFIG_TMPFS)) {
		if (!saved_root_name[0] && !root_fs_names)
			is_tmpfs = true;
		else if (root_fs_names && !!strstr(root_fs_names, "tmpfs"))
			is_tmpfs = true;
	}
}
Commit	Line	Data
457c8996	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	#include <linux/module.h>
	3	#include <linux/sched.h>
	4	#include <linux/ctype.h>
	5	#include <linux/fd.h>
	6	#include <linux/tty.h>
	7	#include <linux/suspend.h>
	8	#include <linux/root_dev.h>
	9	#include <linux/security.h>
	10	#include <linux/delay.h>
d53d9f16	11	#include <linux/mount.h>
d779249e	12	#include <linux/device.h>
46595390	13	#include <linux/init.h>
011e3fcd	14	#include <linux/fs.h>
82c8253a	15	#include <linux/initrd.h>
22a9d645	16	#include <linux/async.h>
5ad4e53b	17	#include <linux/fs_struct.h>
5a0e3ad6	18	#include <linux/slab.h>
57f150a5	19	#include <linux/ramfs.h>
16203a7a	20	#include <linux/shmem_fs.h>
45071e1c	21	#include <linux/ktime.h>
1da177e4 LT	22
	23	#include <linux/nfs_fs.h>
	24	#include <linux/nfs_fs_sb.h>
	25	#include <linux/nfs_mount.h>
4f5b246b	26	#include <linux/raid/detect.h>
e262e32d	27	#include <uapi/linux/mount.h>
1da177e4 LT	28
	29	#include "do_mounts.h"
	30
9b04c997	31	int root_mountflags = MS_RDONLY \| MS_SILENT;
1da177e4	32	static char __initdata saved_root_name[64];
79975f13	33	static int root_wait;
1da177e4	34
1da177e4 LT	35	dev_t ROOT_DEV;
1da177e4 LT	36
1da177e4 LT	37	static int __init load_ramdisk(char *str)
1da177e4 LT	38	{
c8376994	39	pr_warn("ignoring the deprecated load_ramdisk= option\n");
1da177e4 LT	40	return 1;
	41	}
	42	__setup("load_ramdisk=", load_ramdisk);
	43
	44	static int __init readonly(char *str)
	45	{
	46	if (*str)
	47	return 0;
	48	root_mountflags \|= MS_RDONLY;
	49	return 1;
	50	}
	51
	52	static int __init readwrite(char *str)
	53	{
	54	if (*str)
	55	return 0;
	56	root_mountflags &= ~MS_RDONLY;
	57	return 1;
	58	}
	59
	60	__setup("ro", readonly);
	61	__setup("rw", readwrite);
	62
1da177e4 LT	63	static int __init root_dev_setup(char *line)
1da177e4 LT	64	{
a1d3a6d9	65	strscpy(saved_root_name, line, sizeof(saved_root_name));
1da177e4 LT	66	return 1;
	67	}
	68
	69	__setup("root=", root_dev_setup);
	70
cc1ed754 PO	71	static int __init rootwait_setup(char *str)
	72	{
	73	if (*str)
	74	return 0;
45071e1c	75	root_wait = -1;
cc1ed754 PO	76	return 1;
	77	}
	78
	79	__setup("rootwait", rootwait_setup);
	80
45071e1c LP	81	static int __init rootwait_timeout_setup(char *str)
	82	{
	83	int sec;
	84
	85	if (kstrtoint(str, 0, &sec) \|\| sec < 0) {
	86	pr_warn("ignoring invalid rootwait value\n");
	87	goto ignore;
	88	}
	89
	90	if (check_mul_overflow(sec, MSEC_PER_SEC, &root_wait)) {
	91	pr_warn("ignoring excessive rootwait value\n");
	92	goto ignore;
	93	}
	94
	95	return 1;
	96
	97	ignore:
	98	/* Fallback to indefinite wait */
	99	root_wait = -1;
	100
	101	return 1;
	102	}
	103
	104	__setup("rootwait=", rootwait_timeout_setup);
	105
1da177e4 LT	106	static char * __initdata root_mount_data;
	107	static int __init root_data_setup(char *str)
	108	{
	109	root_mount_data = str;
	110	return 1;
	111	}
	112
	113	static char * __initdata root_fs_names;
	114	static int __init fs_names_setup(char *str)
	115	{
	116	root_fs_names = str;
	117	return 1;
	118	}
	119
	120	static unsigned int __initdata root_delay;
	121	static int __init root_delay_setup(char *str)
	122	{
	123	root_delay = simple_strtoul(str, NULL, 0);
	124	return 1;
	125	}
	126
	127	__setup("rootflags=", root_data_setup);
	128	__setup("rootfstype=", fs_names_setup);
	129	__setup("rootdelay=", root_delay_setup);
	130
b51593c4	131	/* This can return zero length strings. Caller should check */
26e293f7	132	static int __init split_fs_names(char *page, size_t size)
1da177e4	133	{
b51593c4	134	int count = 1;
6e7c1770	135	char *p = page;
1da177e4	136
a1d3a6d9	137	strscpy(p, root_fs_names, size);
6e7c1770	138	while (*p++) {
b51593c4	139	if (p[-1] == ',') {
6e7c1770	140	p[-1] = '\0';
b51593c4 VG	141	count++;
b51593c4 VG	142	}
1da177e4	143	}
e24d12b7	144
6e7c1770	145	return count;
1da177e4 LT	146	}
1da177e4 LT	147
cccaa5e3 DB	148	static int __init do_mount_root(const char name, const char fs,
cccaa5e3 DB	149	const int flags, const void *data)
1da177e4	150	{
d8c9584e	151	struct super_block *s;
7de7de7c LT	152	struct page *p = NULL;
7de7de7c LT	153	char *data_page = NULL;
cccaa5e3 DB	154	int ret;
cccaa5e3 DB	155
7de7de7c	156	if (data) {
c60166f0	157	/* init_mount() requires a full page as fifth argument */
7de7de7c LT	158	p = alloc_page(GFP_KERNEL);
	159	if (!p)
	160	return -ENOMEM;
	161	data_page = page_address(p);
07f8230b	162	strscpy_pad(data_page, data, PAGE_SIZE);
7de7de7c	163	}
cccaa5e3	164
c60166f0	165	ret = init_mount(name, "/root", fs, flags, data_page);
cccaa5e3 DB	166	if (ret)
cccaa5e3 DB	167	goto out;
1da177e4	168
db63f1e3	169	init_chdir("/root");
d8c9584e AV	170	s = current->fs->pwd.dentry->d_sb;
d8c9584e AV	171	ROOT_DEV = s->s_dev;
80cdc6da MSB	172	printk(KERN_INFO
80cdc6da MSB	173	"VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
d8c9584e	174	s->s_type->name,
bc98a42c	175	sb_rdonly(s) ? " readonly" : "",
d8c9584e	176	MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
cccaa5e3 DB	177
cccaa5e3 DB	178	out:
7de7de7c LT	179	if (p)
7de7de7c LT	180	put_page(p);
cccaa5e3	181	return ret;
1da177e4 LT	182	}
1da177e4 LT	183
c8643c72	184	void __init mount_root_generic(char name, char pretty_name, int flags)
1da177e4	185	{
75f296d9	186	struct page *page = alloc_page(GFP_KERNEL);
a608ca21	187	char *fs_names = page_address(page);
1da177e4 LT	188	char *p;
1da177e4 LT	189	char b[BDEVNAME_SIZE];
6e7c1770	190	int num_fs, i;
1da177e4	191
ea3edd4d CH	192	scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)",
ea3edd4d CH	193	MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
e24d12b7	194	if (root_fs_names)
26e293f7	195	num_fs = split_fs_names(fs_names, PAGE_SIZE);
e24d12b7	196	else
6e7c1770	197	num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
1da177e4	198	retry:
6e7c1770	199	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) {
b51593c4 VG	200	int err;
	201
	202	if (!*p)
	203	continue;
	204	err = do_mount_root(name, p, flags, root_mount_data);
1da177e4 LT	205	switch (err) {
	206	case 0:
	207	goto out;
	208	case -EACCES:
1da177e4	209	case -EINVAL:
386dc41c CB	210	#ifdef CONFIG_BLOCK
	211	init_flush_fput();
	212	#endif
1da177e4 LT	213	continue;
	214	}
	215	/*
	216	* Allow the user to distinguish between failed sys_open
	217	* and bad superblock on root device.
dd2a345f	218	* and give them a list of the available devices
1da177e4	219	*/
0e0cb892	220	printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
c8643c72	221	pretty_name, b, err);
dd2a345f	222	printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
dd2a345f	223	printk_all_partitions();
6aee6723 AC	224
	225	if (root_fs_names)
	226	num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
	227	if (!num_fs)
	228	pr_err("Can't find any bdev filesystem to be used for mount!\n");
	229	else {
	230	pr_err("List of all bdev filesystems:\n");
	231	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
	232	pr_err(" %s", p);
	233	pr_err("\n");
	234	}
	235
1da177e4 LT	236	panic("VFS: Unable to mount root fs on %s", b);
1da177e4 LT	237	}
e462ec50 DH	238	if (!(flags & SB_RDONLY)) {
e462ec50 DH	239	flags \|= SB_RDONLY;
10975933 MS	240	goto retry;
10975933 MS	241	}
be6e028b	242
dd2a345f DG	243	printk("List of all partitions:\n");
dd2a345f DG	244	printk_all_partitions();
be6e028b	245	printk("No filesystem could mount root, tried: ");
6e7c1770	246	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
be6e028b AW	247	printk(" %s", p);
be6e028b AW	248	printk("\n");
84d2b696	249	panic("VFS: Unable to mount root fs on \"%s\" or %s", pretty_name, b);
1da177e4	250	out:
a608ca21	251	put_page(page);
1da177e4 LT	252	}
	253
	254	#ifdef CONFIG_ROOT_NFS
43717c7d CL	255
	256	#define NFSROOT_TIMEOUT_MIN 5
	257	#define NFSROOT_TIMEOUT_MAX 30
	258	#define NFSROOT_RETRY_MAX 5
	259
a6a41d39	260	static void __init mount_nfs_root(void)
1da177e4	261	{
56463e50	262	char root_dev, root_data;
43717c7d	263	unsigned int timeout;
a6a41d39	264	int try;
1da177e4	265
a6a41d39 CH	266	if (nfs_root_data(&root_dev, &root_data))
a6a41d39 CH	267	goto fail;
43717c7d CL	268
	269	/*
	270	* The server or network may not be ready, so try several
	271	* times. Stop after a few tries in case the client wants
	272	* to fall back to other boot methods.
	273	*/
	274	timeout = NFSROOT_TIMEOUT_MIN;
	275	for (try = 1; ; try++) {
a6a41d39 CH	276	if (!do_mount_root(root_dev, "nfs", root_mountflags, root_data))
a6a41d39 CH	277	return;
43717c7d CL	278	if (try > NFSROOT_RETRY_MAX)
	279	break;
	280
	281	/* Wait, in case the server refused us immediately */
	282	ssleep(timeout);
	283	timeout <<= 1;
	284	if (timeout > NFSROOT_TIMEOUT_MAX)
	285	timeout = NFSROOT_TIMEOUT_MAX;
	286	}
a6a41d39 CH	287	fail:
a6a41d39 CH	288	pr_err("VFS: Unable to mount root fs via NFS.\n");
1da177e4	289	}
a6a41d39 CH	290	#else
	291	static inline void mount_nfs_root(void)
	292	{
1da177e4	293	}
a6a41d39	294	#endif /* CONFIG_ROOT_NFS */
1da177e4	295
8902dd52 PAS	296	#ifdef CONFIG_CIFS_ROOT
8902dd52 PAS	297
8902dd52 PAS	298	#define CIFSROOT_TIMEOUT_MIN 5
	299	#define CIFSROOT_TIMEOUT_MAX 30
	300	#define CIFSROOT_RETRY_MAX 5
	301
a6a41d39	302	static void __init mount_cifs_root(void)
8902dd52 PAS	303	{
	304	char root_dev, root_data;
	305	unsigned int timeout;
a6a41d39	306	int try;
8902dd52	307
a6a41d39 CH	308	if (cifs_root_data(&root_dev, &root_data))
a6a41d39 CH	309	goto fail;
8902dd52 PAS	310
	311	timeout = CIFSROOT_TIMEOUT_MIN;
	312	for (try = 1; ; try++) {
a6a41d39 CH	313	if (!do_mount_root(root_dev, "cifs", root_mountflags,
	314	root_data))
	315	return;
8902dd52 PAS	316	if (try > CIFSROOT_RETRY_MAX)
	317	break;
	318
	319	ssleep(timeout);
	320	timeout <<= 1;
	321	if (timeout > CIFSROOT_TIMEOUT_MAX)
	322	timeout = CIFSROOT_TIMEOUT_MAX;
	323	}
a6a41d39 CH	324	fail:
a6a41d39 CH	325	pr_err("VFS: Unable to mount root fs via SMB.\n");
8902dd52	326	}
a6a41d39 CH	327	#else
	328	static inline void mount_cifs_root(void)
	329	{
	330	}
	331	#endif /* CONFIG_CIFS_ROOT */
8902dd52	332
f9259be6 CH	333	static bool __init fs_is_nodev(char *fstype)
	334	{
	335	struct file_system_type *fs = get_fs_type(fstype);
	336	bool ret = false;
	337
	338	if (fs) {
	339	ret = !(fs->fs_flags & FS_REQUIRES_DEV);
	340	put_filesystem(fs);
	341	}
	342
	343	return ret;
	344	}
	345
c8643c72	346	static int __init mount_nodev_root(char *root_device_name)
f9259be6 CH	347	{
	348	char fs_names, fstype;
	349	int err = -EINVAL;
6e7c1770	350	int num_fs, i;
f9259be6 CH	351
	352	fs_names = (void *)__get_free_page(GFP_KERNEL);
	353	if (!fs_names)
	354	return -EINVAL;
26e293f7	355	num_fs = split_fs_names(fs_names, PAGE_SIZE);
f9259be6	356
6e7c1770 CH	357	for (i = 0, fstype = fs_names; i < num_fs;
6e7c1770 CH	358	i++, fstype += strlen(fstype) + 1) {
b51593c4 VG	359	if (!*fstype)
b51593c4 VG	360	continue;
f9259be6 CH	361	if (!fs_is_nodev(fstype))
	362	continue;
	363	err = do_mount_root(root_device_name, fstype, root_mountflags,
	364	root_mount_data);
	365	if (!err)
	366	break;
f9259be6 CH	367	}
	368
	369	free_page((unsigned long)fs_names);
	370	return err;
	371	}
	372
9361401e	373	#ifdef CONFIG_BLOCK
c8643c72	374	static void __init mount_block_root(char *root_device_name)
1da177e4	375	{
a6a41d39 CH	376	int err = create_dev("/dev/root", ROOT_DEV);
	377
	378	if (err < 0)
	379	pr_emerg("Failed to create /dev/root: %d\n", err);
c8643c72	380	mount_root_generic("/dev/root", root_device_name, root_mountflags);
a6a41d39 CH	381	}
a6a41d39 CH	382	#else
c8643c72	383	static inline void mount_block_root(char *root_device_name)
a6a41d39 CH	384	{
	385	}
	386	#endif /* CONFIG_BLOCK */
c69e3c3a	387
c8643c72	388	void __init mount_root(char *root_device_name)
a6a41d39 CH	389	{
	390	switch (ROOT_DEV) {
	391	case Root_NFS:
	392	mount_nfs_root();
	393	break;
	394	case Root_CIFS:
	395	mount_cifs_root();
	396	break;
07d63cbb CH	397	case Root_Generic:
	398	mount_root_generic(root_device_name, root_device_name,
	399	root_mountflags);
	400	break;
a6a41d39	401	case 0:
c8643c72 CH	402	if (root_device_name && root_fs_names &&
c8643c72 CH	403	mount_nodev_root(root_device_name) == 0)
a6a41d39 CH	404	break;
	405	fallthrough;
	406	default:
c8643c72	407	mount_block_root(root_device_name);
a6a41d39	408	break;
1da177e4	409	}
1da177e4 LT	410	}
1da177e4 LT	411
3701c600 CH	412	/* wait for any asynchronous scanning to complete */
	413	static void __init wait_for_root(char *root_device_name)
	414	{
45071e1c LP	415	ktime_t end;
45071e1c LP	416
3701c600	417	if (ROOT_DEV != 0)
c8376994	418	return;
c69e3c3a	419
3701c600 CH	420	pr_info("Waiting for root device %s...\n", root_device_name);
3701c600 CH	421
45071e1c LP	422	end = ktime_add_ms(ktime_get_raw(), root_wait);
45071e1c LP	423
cf056a43	424	while (!driver_probe_done() \|\|
45071e1c	425	early_lookup_bdev(root_device_name, &ROOT_DEV) < 0) {
3701c600	426	msleep(5);
45071e1c LP	427	if (root_wait > 0 && ktime_after(ktime_get_raw(), end))
	428	break;
	429	}
	430
3701c600 CH	431	async_synchronize_full();
	432
	433	}
	434
07d63cbb CH	435	static dev_t __init parse_root_device(char *root_device_name)
07d63cbb CH	436	{
079caa35	437	int error;
cf056a43 CH	438	dev_t dev;
cf056a43 CH	439
07d63cbb CH	440	if (!strncmp(root_device_name, "mtd", 3) \|\|
	441	!strncmp(root_device_name, "ubi", 3))
	442	return Root_Generic;
c0c1a7dc CH	443	if (strcmp(root_device_name, "/dev/nfs") == 0)
	444	return Root_NFS;
	445	if (strcmp(root_device_name, "/dev/cifs") == 0)
	446	return Root_CIFS;
	447	if (strcmp(root_device_name, "/dev/ram") == 0)
	448	return Root_RAM0;
cf056a43	449
079caa35 CH	450	error = early_lookup_bdev(root_device_name, &dev);
	451	if (error) {
	452	if (error == -EINVAL && root_wait) {
	453	pr_err("Disabling rootwait; root= is invalid.\n");
	454	root_wait = 0;
	455	}
cf056a43	456	return 0;
c69e3c3a	457	}
cf056a43	458	return dev;
1da177e4 LT	459	}
	460
	461	/*
	462	* Prepare the namespace - decide what/where to mount, load ramdisks, etc.
	463	*/
	464	void __init prepare_namespace(void)
	465	{
1da177e4	466	if (root_delay) {
ca75b4d8	467	printk(KERN_INFO "Waiting %d sec before mounting root device...\n",
1da177e4 LT	468	root_delay);
	469	ssleep(root_delay);
	470	}
	471
216773a7 AV	472	/*
	473	* wait for the known devices to complete their probing
	474	*
	475	* Note: this is a potential source of long boot delays.
	476	* For example, it is not atypical to wait 5 seconds here
	477	* for the touchpad of a laptop to initialize.
	478	*/
	479	wait_for_device_probe();
d779249e	480
1da177e4 LT	481	md_run_setup();
1da177e4 LT	482
07d63cbb CH	483	if (saved_root_name[0])
07d63cbb CH	484	ROOT_DEV = parse_root_device(saved_root_name);
1da177e4	485
73231b58	486	if (initrd_load(saved_root_name))
1da177e4 LT	487	goto out;
1da177e4 LT	488
3701c600 CH	489	if (root_wait)
3701c600 CH	490	wait_for_root(saved_root_name);
73231b58	491	mount_root(saved_root_name);
1da177e4	492	out:
5e787dbf	493	devtmpfs_mount();
c60166f0	494	init_mount(".", "/", NULL, MS_MOVE, NULL);
4b7ca501	495	init_chroot(".");
1da177e4	496	}
57f150a5	497
6e19eded	498	static bool is_tmpfs;
f3235626	499	static int rootfs_init_fs_context(struct fs_context *fc)
57f150a5	500	{
6e19eded	501	if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
f3235626	502	return shmem_init_fs_context(fc);
6e19eded	503
f3235626	504	return ramfs_init_fs_context(fc);
57f150a5 RL	505	}
57f150a5 RL	506
fd3e007f	507	struct file_system_type rootfs_fs_type = {
57f150a5	508	.name = "rootfs",
f3235626	509	.init_fs_context = rootfs_init_fs_context,
57f150a5 RL	510	.kill_sb = kill_litter_super,
	511	};
	512
037f11b4	513	void __init init_rootfs(void)
57f150a5	514	{
21528c69 SB	515	if (IS_ENABLED(CONFIG_TMPFS)) {
	516	if (!saved_root_name[0] && !root_fs_names)
	517	is_tmpfs = true;
	518	else if (root_fs_names && !!strstr(root_fs_names, "tmpfs"))
	519	is_tmpfs = true;
	520	}
57f150a5	521	}