[thirdparty/linux.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);
		/* zero-pad. init_mount() will make sure it's terminated */
		strncpy(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);
c60166f0	162	/* zero-pad. init_mount() will make sure it's terminated */
7de7de7c LT	163	strncpy(data_page, data, PAGE_SIZE);
7de7de7c LT	164	}
cccaa5e3	165
c60166f0	166	ret = init_mount(name, "/root", fs, flags, data_page);
cccaa5e3 DB	167	if (ret)
cccaa5e3 DB	168	goto out;
1da177e4	169
db63f1e3	170	init_chdir("/root");
d8c9584e AV	171	s = current->fs->pwd.dentry->d_sb;
d8c9584e AV	172	ROOT_DEV = s->s_dev;
80cdc6da MSB	173	printk(KERN_INFO
80cdc6da MSB	174	"VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
d8c9584e	175	s->s_type->name,
bc98a42c	176	sb_rdonly(s) ? " readonly" : "",
d8c9584e	177	MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
cccaa5e3 DB	178
cccaa5e3 DB	179	out:
7de7de7c LT	180	if (p)
7de7de7c LT	181	put_page(p);
cccaa5e3	182	return ret;
1da177e4 LT	183	}
1da177e4 LT	184
c8643c72	185	void __init mount_root_generic(char name, char pretty_name, int flags)
1da177e4	186	{
75f296d9	187	struct page *page = alloc_page(GFP_KERNEL);
a608ca21	188	char *fs_names = page_address(page);
1da177e4 LT	189	char *p;
1da177e4 LT	190	char b[BDEVNAME_SIZE];
6e7c1770	191	int num_fs, i;
1da177e4	192
ea3edd4d CH	193	scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)",
ea3edd4d CH	194	MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
e24d12b7	195	if (root_fs_names)
26e293f7	196	num_fs = split_fs_names(fs_names, PAGE_SIZE);
e24d12b7	197	else
6e7c1770	198	num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
1da177e4	199	retry:
6e7c1770	200	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) {
b51593c4 VG	201	int err;
	202
	203	if (!*p)
	204	continue;
	205	err = do_mount_root(name, p, flags, root_mount_data);
1da177e4 LT	206	switch (err) {
	207	case 0:
	208	goto out;
	209	case -EACCES:
1da177e4	210	case -EINVAL:
386dc41c CB	211	#ifdef CONFIG_BLOCK
	212	init_flush_fput();
	213	#endif
1da177e4 LT	214	continue;
	215	}
	216	/*
	217	* Allow the user to distinguish between failed sys_open
	218	* and bad superblock on root device.
dd2a345f	219	* and give them a list of the available devices
1da177e4	220	*/
0e0cb892	221	printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
c8643c72	222	pretty_name, b, err);
dd2a345f	223	printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
dd2a345f	224	printk_all_partitions();
6aee6723 AC	225
	226	if (root_fs_names)
	227	num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
	228	if (!num_fs)
	229	pr_err("Can't find any bdev filesystem to be used for mount!\n");
	230	else {
	231	pr_err("List of all bdev filesystems:\n");
	232	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
	233	pr_err(" %s", p);
	234	pr_err("\n");
	235	}
	236
1da177e4 LT	237	panic("VFS: Unable to mount root fs on %s", b);
1da177e4 LT	238	}
e462ec50 DH	239	if (!(flags & SB_RDONLY)) {
e462ec50 DH	240	flags \|= SB_RDONLY;
10975933 MS	241	goto retry;
10975933 MS	242	}
be6e028b	243
dd2a345f DG	244	printk("List of all partitions:\n");
dd2a345f DG	245	printk_all_partitions();
be6e028b	246	printk("No filesystem could mount root, tried: ");
6e7c1770	247	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
be6e028b AW	248	printk(" %s", p);
be6e028b AW	249	printk("\n");
84d2b696	250	panic("VFS: Unable to mount root fs on \"%s\" or %s", pretty_name, b);
1da177e4	251	out:
a608ca21	252	put_page(page);
1da177e4 LT	253	}
	254
	255	#ifdef CONFIG_ROOT_NFS
43717c7d CL	256
	257	#define NFSROOT_TIMEOUT_MIN 5
	258	#define NFSROOT_TIMEOUT_MAX 30
	259	#define NFSROOT_RETRY_MAX 5
	260
a6a41d39	261	static void __init mount_nfs_root(void)
1da177e4	262	{
56463e50	263	char root_dev, root_data;
43717c7d	264	unsigned int timeout;
a6a41d39	265	int try;
1da177e4	266
a6a41d39 CH	267	if (nfs_root_data(&root_dev, &root_data))
a6a41d39 CH	268	goto fail;
43717c7d CL	269
	270	/*
	271	* The server or network may not be ready, so try several
	272	* times. Stop after a few tries in case the client wants
	273	* to fall back to other boot methods.
	274	*/
	275	timeout = NFSROOT_TIMEOUT_MIN;
	276	for (try = 1; ; try++) {
a6a41d39 CH	277	if (!do_mount_root(root_dev, "nfs", root_mountflags, root_data))
a6a41d39 CH	278	return;
43717c7d CL	279	if (try > NFSROOT_RETRY_MAX)
	280	break;
	281
	282	/* Wait, in case the server refused us immediately */
	283	ssleep(timeout);
	284	timeout <<= 1;
	285	if (timeout > NFSROOT_TIMEOUT_MAX)
	286	timeout = NFSROOT_TIMEOUT_MAX;
	287	}
a6a41d39 CH	288	fail:
a6a41d39 CH	289	pr_err("VFS: Unable to mount root fs via NFS.\n");
1da177e4	290	}
a6a41d39 CH	291	#else
	292	static inline void mount_nfs_root(void)
	293	{
1da177e4	294	}
a6a41d39	295	#endif /* CONFIG_ROOT_NFS */
1da177e4	296
8902dd52 PAS	297	#ifdef CONFIG_CIFS_ROOT
8902dd52 PAS	298
8902dd52 PAS	299	#define CIFSROOT_TIMEOUT_MIN 5
	300	#define CIFSROOT_TIMEOUT_MAX 30
	301	#define CIFSROOT_RETRY_MAX 5
	302
a6a41d39	303	static void __init mount_cifs_root(void)
8902dd52 PAS	304	{
	305	char root_dev, root_data;
	306	unsigned int timeout;
a6a41d39	307	int try;
8902dd52	308
a6a41d39 CH	309	if (cifs_root_data(&root_dev, &root_data))
a6a41d39 CH	310	goto fail;
8902dd52 PAS	311
	312	timeout = CIFSROOT_TIMEOUT_MIN;
	313	for (try = 1; ; try++) {
a6a41d39 CH	314	if (!do_mount_root(root_dev, "cifs", root_mountflags,
	315	root_data))
	316	return;
8902dd52 PAS	317	if (try > CIFSROOT_RETRY_MAX)
	318	break;
	319
	320	ssleep(timeout);
	321	timeout <<= 1;
	322	if (timeout > CIFSROOT_TIMEOUT_MAX)
	323	timeout = CIFSROOT_TIMEOUT_MAX;
	324	}
a6a41d39 CH	325	fail:
a6a41d39 CH	326	pr_err("VFS: Unable to mount root fs via SMB.\n");
8902dd52	327	}
a6a41d39 CH	328	#else
	329	static inline void mount_cifs_root(void)
	330	{
	331	}
	332	#endif /* CONFIG_CIFS_ROOT */
8902dd52	333
f9259be6 CH	334	static bool __init fs_is_nodev(char *fstype)
	335	{
	336	struct file_system_type *fs = get_fs_type(fstype);
	337	bool ret = false;
	338
	339	if (fs) {
	340	ret = !(fs->fs_flags & FS_REQUIRES_DEV);
	341	put_filesystem(fs);
	342	}
	343
	344	return ret;
	345	}
	346
c8643c72	347	static int __init mount_nodev_root(char *root_device_name)
f9259be6 CH	348	{
	349	char fs_names, fstype;
	350	int err = -EINVAL;
6e7c1770	351	int num_fs, i;
f9259be6 CH	352
	353	fs_names = (void *)__get_free_page(GFP_KERNEL);
	354	if (!fs_names)
	355	return -EINVAL;
26e293f7	356	num_fs = split_fs_names(fs_names, PAGE_SIZE);
f9259be6	357
6e7c1770 CH	358	for (i = 0, fstype = fs_names; i < num_fs;
6e7c1770 CH	359	i++, fstype += strlen(fstype) + 1) {
b51593c4 VG	360	if (!*fstype)
b51593c4 VG	361	continue;
f9259be6 CH	362	if (!fs_is_nodev(fstype))
	363	continue;
	364	err = do_mount_root(root_device_name, fstype, root_mountflags,
	365	root_mount_data);
	366	if (!err)
	367	break;
f9259be6 CH	368	}
	369
	370	free_page((unsigned long)fs_names);
	371	return err;
	372	}
	373
9361401e	374	#ifdef CONFIG_BLOCK
c8643c72	375	static void __init mount_block_root(char *root_device_name)
1da177e4	376	{
a6a41d39 CH	377	int err = create_dev("/dev/root", ROOT_DEV);
	378
	379	if (err < 0)
	380	pr_emerg("Failed to create /dev/root: %d\n", err);
c8643c72	381	mount_root_generic("/dev/root", root_device_name, root_mountflags);
a6a41d39 CH	382	}
a6a41d39 CH	383	#else
c8643c72	384	static inline void mount_block_root(char *root_device_name)
a6a41d39 CH	385	{
	386	}
	387	#endif /* CONFIG_BLOCK */
c69e3c3a	388
c8643c72	389	void __init mount_root(char *root_device_name)
a6a41d39 CH	390	{
	391	switch (ROOT_DEV) {
	392	case Root_NFS:
	393	mount_nfs_root();
	394	break;
	395	case Root_CIFS:
	396	mount_cifs_root();
	397	break;
07d63cbb CH	398	case Root_Generic:
	399	mount_root_generic(root_device_name, root_device_name,
	400	root_mountflags);
	401	break;
a6a41d39	402	case 0:
c8643c72 CH	403	if (root_device_name && root_fs_names &&
c8643c72 CH	404	mount_nodev_root(root_device_name) == 0)
a6a41d39 CH	405	break;
	406	fallthrough;
	407	default:
c8643c72	408	mount_block_root(root_device_name);
a6a41d39	409	break;
1da177e4	410	}
1da177e4 LT	411	}
1da177e4 LT	412
3701c600 CH	413	/* wait for any asynchronous scanning to complete */
	414	static void __init wait_for_root(char *root_device_name)
	415	{
45071e1c LP	416	ktime_t end;
45071e1c LP	417
3701c600	418	if (ROOT_DEV != 0)
c8376994	419	return;
c69e3c3a	420
3701c600 CH	421	pr_info("Waiting for root device %s...\n", root_device_name);
3701c600 CH	422
45071e1c LP	423	end = ktime_add_ms(ktime_get_raw(), root_wait);
45071e1c LP	424
cf056a43	425	while (!driver_probe_done() \|\|
45071e1c	426	early_lookup_bdev(root_device_name, &ROOT_DEV) < 0) {
3701c600	427	msleep(5);
45071e1c LP	428	if (root_wait > 0 && ktime_after(ktime_get_raw(), end))
	429	break;
	430	}
	431
3701c600 CH	432	async_synchronize_full();
	433
	434	}
	435
07d63cbb CH	436	static dev_t __init parse_root_device(char *root_device_name)
07d63cbb CH	437	{
079caa35	438	int error;
cf056a43 CH	439	dev_t dev;
cf056a43 CH	440
07d63cbb CH	441	if (!strncmp(root_device_name, "mtd", 3) \|\|
	442	!strncmp(root_device_name, "ubi", 3))
	443	return Root_Generic;
c0c1a7dc CH	444	if (strcmp(root_device_name, "/dev/nfs") == 0)
	445	return Root_NFS;
	446	if (strcmp(root_device_name, "/dev/cifs") == 0)
	447	return Root_CIFS;
	448	if (strcmp(root_device_name, "/dev/ram") == 0)
	449	return Root_RAM0;
cf056a43	450
079caa35 CH	451	error = early_lookup_bdev(root_device_name, &dev);
	452	if (error) {
	453	if (error == -EINVAL && root_wait) {
	454	pr_err("Disabling rootwait; root= is invalid.\n");
	455	root_wait = 0;
	456	}
cf056a43	457	return 0;
c69e3c3a	458	}
cf056a43	459	return dev;
1da177e4 LT	460	}
	461
	462	/*
	463	* Prepare the namespace - decide what/where to mount, load ramdisks, etc.
	464	*/
	465	void __init prepare_namespace(void)
	466	{
1da177e4	467	if (root_delay) {
ca75b4d8	468	printk(KERN_INFO "Waiting %d sec before mounting root device...\n",
1da177e4 LT	469	root_delay);
	470	ssleep(root_delay);
	471	}
	472
216773a7 AV	473	/*
	474	* wait for the known devices to complete their probing
	475	*
	476	* Note: this is a potential source of long boot delays.
	477	* For example, it is not atypical to wait 5 seconds here
	478	* for the touchpad of a laptop to initialize.
	479	*/
	480	wait_for_device_probe();
d779249e	481
1da177e4 LT	482	md_run_setup();
1da177e4 LT	483
07d63cbb CH	484	if (saved_root_name[0])
07d63cbb CH	485	ROOT_DEV = parse_root_device(saved_root_name);
1da177e4	486
73231b58	487	if (initrd_load(saved_root_name))
1da177e4 LT	488	goto out;
1da177e4 LT	489
3701c600 CH	490	if (root_wait)
3701c600 CH	491	wait_for_root(saved_root_name);
73231b58	492	mount_root(saved_root_name);
1da177e4	493	out:
5e787dbf	494	devtmpfs_mount();
c60166f0	495	init_mount(".", "/", NULL, MS_MOVE, NULL);
4b7ca501	496	init_chroot(".");
1da177e4	497	}
57f150a5	498
6e19eded	499	static bool is_tmpfs;
f3235626	500	static int rootfs_init_fs_context(struct fs_context *fc)
57f150a5	501	{
6e19eded	502	if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
f3235626	503	return shmem_init_fs_context(fc);
6e19eded	504
f3235626	505	return ramfs_init_fs_context(fc);
57f150a5 RL	506	}
57f150a5 RL	507
fd3e007f	508	struct file_system_type rootfs_fs_type = {
57f150a5	509	.name = "rootfs",
f3235626	510	.init_fs_context = rootfs_init_fs_context,
57f150a5 RL	511	.kill_sb = kill_litter_super,
	512	};
	513
037f11b4	514	void __init init_rootfs(void)
57f150a5	515	{
21528c69 SB	516	if (IS_ENABLED(CONFIG_TMPFS)) {
	517	if (!saved_root_name[0] && !root_fs_names)
	518	is_tmpfs = true;
	519	else if (root_fs_names && !!strstr(root_fs_names, "tmpfs"))
	520	is_tmpfs = true;
	521	}
57f150a5	522	}