1 #include <linux/module.h>
2 #include <linux/sched.h>
3 #include <linux/ctype.h>
6 #include <linux/suspend.h>
7 #include <linux/root_dev.h>
8 #include <linux/security.h>
9 #include <linux/delay.h>
10 #include <linux/genhd.h>
11 #include <linux/mount.h>
12 #include <linux/device.h>
13 #include <linux/init.h>
15 #include <linux/initrd.h>
16 #include <linux/async.h>
17 #include <linux/fs_struct.h>
18 #include <linux/slab.h>
20 #include <linux/nfs_fs.h>
21 #include <linux/nfs_fs_sb.h>
22 #include <linux/nfs_mount.h>
24 #include "do_mounts.h"
26 int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
28 int root_mountflags = MS_RDONLY | MS_SILENT;
29 static char * __initdata root_device_name;
30 static char __initdata saved_root_name[64];
31 static int __initdata root_wait;
35 static int __init load_ramdisk(char *str)
37 rd_doload = simple_strtol(str,NULL,0) & 3;
40 __setup("load_ramdisk=", load_ramdisk);
42 static int __init readonly(char *str)
46 root_mountflags |= MS_RDONLY;
50 static int __init readwrite(char *str)
54 root_mountflags &= ~MS_RDONLY;
58 __setup("ro", readonly);
59 __setup("rw", readwrite);
63 * match_dev_by_uuid - callback for finding a partition using its uuid
64 * @dev: device passed in by the caller
65 * @data: opaque pointer to a 36 byte char array with a UUID
67 * Returns 1 if the device matches, and 0 otherwise.
69 static int match_dev_by_uuid(struct device *dev, void *data)
72 struct hd_struct *part = dev_to_part(dev);
77 if (memcmp(uuid, part->info->uuid, sizeof(part->info->uuid)))
87 * devt_from_partuuid - looks up the dev_t of a partition by its UUID
88 * @uuid: 36 byte char array containing a hex ascii UUID
90 * The function will return the first partition which contains a matching
91 * UUID value in its partition_meta_info struct. This does not search
92 * by filesystem UUIDs.
94 * Returns the matching dev_t on success or 0 on failure.
96 static dev_t devt_from_partuuid(char *uuid_str)
99 struct device *dev = NULL;
102 /* Pack the requested UUID in the expected format. */
103 part_pack_uuid(uuid_str, uuid);
105 dev = class_find_device(&block_class, NULL, uuid, &match_dev_by_uuid);
118 * Convert a name into device number. We accept the following variants:
120 * 1) device number in hexadecimal represents itself
121 * 2) /dev/nfs represents Root_NFS (0xff)
122 * 3) /dev/<disk_name> represents the device number of disk
123 * 4) /dev/<disk_name><decimal> represents the device number
124 * of partition - device number of disk plus the partition number
125 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is
126 * used when disk name of partitioned disk ends on a digit.
127 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
128 * unique id of a partition if the partition table provides it.
130 * If name doesn't have fall into the categories above, we return (0,0).
131 * block_class is used to check if something is a disk name. If the disk
132 * name contains slashes, the device name has them replaced with
136 dev_t name_to_dev_t(char *name)
144 if (strncmp(name, "PARTUUID=", 9) == 0) {
146 if (strlen(name) != 36)
148 res = devt_from_partuuid(name);
155 if (strncmp(name, "/dev/", 5) != 0) {
158 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
159 res = MKDEV(maj, min);
160 if (maj != MAJOR(res) || min != MINOR(res))
163 res = new_decode_dev(simple_strtoul(name, &p, 16));
172 if (strcmp(name, "nfs") == 0)
175 if (strcmp(name, "ram") == 0)
178 if (strlen(name) > 31)
184 res = blk_lookup_devt(s, 0);
189 * try non-existent, but valid partition, which may only exist
190 * after revalidating the disk, like partitioned md devices
192 while (p > s && isdigit(p[-1]))
194 if (p == s || !*p || *p == '0')
197 /* try disk name without <part number> */
198 part = simple_strtoul(p, NULL, 10);
200 res = blk_lookup_devt(s, part);
204 /* try disk name without p<part number> */
205 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
208 res = blk_lookup_devt(s, part);
218 static int __init root_dev_setup(char *line)
220 strlcpy(saved_root_name, line, sizeof(saved_root_name));
224 __setup("root=", root_dev_setup);
226 static int __init rootwait_setup(char *str)
234 __setup("rootwait", rootwait_setup);
236 static char * __initdata root_mount_data;
237 static int __init root_data_setup(char *str)
239 root_mount_data = str;
243 static char * __initdata root_fs_names;
244 static int __init fs_names_setup(char *str)
250 static unsigned int __initdata root_delay;
251 static int __init root_delay_setup(char *str)
253 root_delay = simple_strtoul(str, NULL, 0);
257 __setup("rootflags=", root_data_setup);
258 __setup("rootfstype=", fs_names_setup);
259 __setup("rootdelay=", root_delay_setup);
261 static void __init get_fs_names(char *page)
266 strcpy(page, root_fs_names);
272 int len = get_filesystem_list(page);
276 for (p = page-1; p; p = next) {
277 next = strchr(++p, '\n');
280 while ((*s++ = *p++) != '\n')
288 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
290 int err = sys_mount(name, "/root", fs, flags, data);
294 sys_chdir((const char __user __force *)"/root");
295 ROOT_DEV = current->fs->pwd.mnt->mnt_sb->s_dev;
297 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
298 current->fs->pwd.mnt->mnt_sb->s_type->name,
299 current->fs->pwd.mnt->mnt_sb->s_flags & MS_RDONLY ?
300 " readonly" : "", MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
304 void __init mount_block_root(char *name, int flags)
306 char *fs_names = __getname_gfp(GFP_KERNEL
307 | __GFP_NOTRACK_FALSE_POSITIVE);
310 char b[BDEVNAME_SIZE];
312 const char *b = name;
315 get_fs_names(fs_names);
317 for (p = fs_names; *p; p += strlen(p)+1) {
318 int err = do_mount_root(name, p, flags, root_mount_data);
329 * Allow the user to distinguish between failed sys_open
330 * and bad superblock on root device.
331 * and give them a list of the available devices
334 __bdevname(ROOT_DEV, b);
336 printk("VFS: Cannot open root device \"%s\" or %s\n",
337 root_device_name, b);
338 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
340 printk_all_partitions();
341 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
342 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
343 "explicit textual name for \"root=\" boot option.\n");
345 panic("VFS: Unable to mount root fs on %s", b);
348 printk("List of all partitions:\n");
349 printk_all_partitions();
350 printk("No filesystem could mount root, tried: ");
351 for (p = fs_names; *p; p += strlen(p)+1)
355 __bdevname(ROOT_DEV, b);
357 panic("VFS: Unable to mount root fs on %s", b);
362 #ifdef CONFIG_ROOT_NFS
364 #define NFSROOT_TIMEOUT_MIN 5
365 #define NFSROOT_TIMEOUT_MAX 30
366 #define NFSROOT_RETRY_MAX 5
368 static int __init mount_nfs_root(void)
370 char *root_dev, *root_data;
371 unsigned int timeout;
374 err = nfs_root_data(&root_dev, &root_data);
379 * The server or network may not be ready, so try several
380 * times. Stop after a few tries in case the client wants
381 * to fall back to other boot methods.
383 timeout = NFSROOT_TIMEOUT_MIN;
384 for (try = 1; ; try++) {
385 err = do_mount_root(root_dev, "nfs",
386 root_mountflags, root_data);
389 if (try > NFSROOT_RETRY_MAX)
392 /* Wait, in case the server refused us immediately */
395 if (timeout > NFSROOT_TIMEOUT_MAX)
396 timeout = NFSROOT_TIMEOUT_MAX;
402 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
403 void __init change_floppy(char *fmt, ...)
405 struct termios termios;
411 vsprintf(buf, fmt, args);
413 fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
415 sys_ioctl(fd, FDEJECT, 0);
418 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
419 fd = sys_open("/dev/console", O_RDWR, 0);
421 sys_ioctl(fd, TCGETS, (long)&termios);
422 termios.c_lflag &= ~ICANON;
423 sys_ioctl(fd, TCSETSF, (long)&termios);
425 termios.c_lflag |= ICANON;
426 sys_ioctl(fd, TCSETSF, (long)&termios);
432 void __init mount_root(void)
434 #ifdef CONFIG_ROOT_NFS
435 if (ROOT_DEV == Root_NFS) {
436 if (mount_nfs_root())
439 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
443 #ifdef CONFIG_BLK_DEV_FD
444 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
445 /* rd_doload is 2 for a dual initrd/ramload setup */
447 if (rd_load_disk(1)) {
448 ROOT_DEV = Root_RAM1;
449 root_device_name = NULL;
452 change_floppy("root floppy");
456 create_dev("/dev/root", ROOT_DEV);
457 mount_block_root("/dev/root", root_mountflags);
462 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
464 void __init prepare_namespace(void)
469 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
475 * wait for the known devices to complete their probing
477 * Note: this is a potential source of long boot delays.
478 * For example, it is not atypical to wait 5 seconds here
479 * for the touchpad of a laptop to initialize.
481 wait_for_device_probe();
485 if (saved_root_name[0]) {
486 root_device_name = saved_root_name;
487 if (!strncmp(root_device_name, "mtd", 3) ||
488 !strncmp(root_device_name, "ubi", 3)) {
489 mount_block_root(root_device_name, root_mountflags);
492 ROOT_DEV = name_to_dev_t(root_device_name);
493 if (strncmp(root_device_name, "/dev/", 5) == 0)
494 root_device_name += 5;
500 /* wait for any asynchronous scanning to complete */
501 if ((ROOT_DEV == 0) && root_wait) {
502 printk(KERN_INFO "Waiting for root device %s...\n",
504 while (driver_probe_done() != 0 ||
505 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
507 async_synchronize_full();
510 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
512 if (is_floppy && rd_doload && rd_load_disk(0))
513 ROOT_DEV = Root_RAM0;
517 devtmpfs_mount("dev");
518 sys_mount(".", "/", NULL, MS_MOVE, NULL);
519 sys_chroot((const char __user __force *)".");