2 * Many of the syscalls used in this file expect some of the arguments
3 * to be __user pointers not __kernel pointers. To limit the sparse
4 * noise, turn off sparse checking for this file.
8 #warning "Sparse checking disabled for this file"
11 #include <linux/module.h>
12 #include <linux/sched.h>
13 #include <linux/ctype.h>
15 #include <linux/tty.h>
16 #include <linux/suspend.h>
17 #include <linux/root_dev.h>
18 #include <linux/security.h>
19 #include <linux/delay.h>
20 #include <linux/genhd.h>
21 #include <linux/mount.h>
22 #include <linux/device.h>
23 #include <linux/init.h>
25 #include <linux/initrd.h>
26 #include <linux/async.h>
27 #include <linux/fs_struct.h>
28 #include <linux/slab.h>
30 #include <linux/nfs_fs.h>
31 #include <linux/nfs_fs_sb.h>
32 #include <linux/nfs_mount.h>
34 #include "do_mounts.h"
36 int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
38 int root_mountflags = MS_RDONLY | MS_SILENT;
39 static char * __initdata root_device_name;
40 static char __initdata saved_root_name[64];
45 static int __init load_ramdisk(char *str)
47 rd_doload = simple_strtol(str,NULL,0) & 3;
50 __setup("load_ramdisk=", load_ramdisk);
52 static int __init readonly(char *str)
56 root_mountflags |= MS_RDONLY;
60 static int __init readwrite(char *str)
64 root_mountflags &= ~MS_RDONLY;
68 __setup("ro", readonly);
69 __setup("rw", readwrite);
78 * match_dev_by_uuid - callback for finding a partition using its uuid
79 * @dev: device passed in by the caller
80 * @data: opaque pointer to the desired struct uuidcmp to match
82 * Returns 1 if the device matches, and 0 otherwise.
84 static int match_dev_by_uuid(struct device *dev, void *data)
86 struct uuidcmp *cmp = data;
87 struct hd_struct *part = dev_to_part(dev);
92 if (strncasecmp(cmp->uuid, part->info->uuid, cmp->len))
102 * devt_from_partuuid - looks up the dev_t of a partition by its UUID
103 * @uuid: char array containing ascii UUID
105 * The function will return the first partition which contains a matching
106 * UUID value in its partition_meta_info struct. This does not search
107 * by filesystem UUIDs.
109 * If @uuid is followed by a "/PARTNROFF=%d", then the number will be
110 * extracted and used as an offset from the partition identified by the UUID.
112 * Returns the matching dev_t on success or 0 on failure.
114 static dev_t devt_from_partuuid(const char *uuid_str)
118 struct device *dev = NULL;
119 struct gendisk *disk;
120 struct hd_struct *part;
122 bool clear_root_wait = false;
127 slash = strchr(uuid_str, '/');
128 /* Check for optional partition number offset attributes. */
131 /* Explicitly fail on poor PARTUUID syntax. */
132 if (sscanf(slash + 1,
133 "PARTNROFF=%d%c", &offset, &c) != 1) {
134 clear_root_wait = true;
137 cmp.len = slash - uuid_str;
139 cmp.len = strlen(uuid_str);
143 clear_root_wait = true;
147 dev = class_find_device(&block_class, NULL, &cmp,
154 /* Attempt to find the partition by offset. */
159 disk = part_to_disk(dev_to_part(dev));
160 part = disk_get_part(disk, dev_to_part(dev)->partno + offset);
162 res = part_devt(part);
163 put_device(part_to_dev(part));
169 if (clear_root_wait) {
170 pr_err("VFS: PARTUUID= is invalid.\n"
171 "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
173 pr_err("Disabling rootwait; root= is invalid.\n");
181 * Convert a name into device number. We accept the following variants:
183 * 1) device number in hexadecimal represents itself
184 * 2) /dev/nfs represents Root_NFS (0xff)
185 * 3) /dev/<disk_name> represents the device number of disk
186 * 4) /dev/<disk_name><decimal> represents the device number
187 * of partition - device number of disk plus the partition number
188 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is
189 * used when disk name of partitioned disk ends on a digit.
190 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
191 * unique id of a partition if the partition table provides it.
192 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
193 * a partition with a known unique id.
195 * If name doesn't have fall into the categories above, we return (0,0).
196 * block_class is used to check if something is a disk name. If the disk
197 * name contains slashes, the device name has them replaced with
201 dev_t name_to_dev_t(char *name)
209 if (strncmp(name, "PARTUUID=", 9) == 0) {
211 res = devt_from_partuuid(name);
218 if (strncmp(name, "/dev/", 5) != 0) {
221 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
222 res = MKDEV(maj, min);
223 if (maj != MAJOR(res) || min != MINOR(res))
226 res = new_decode_dev(simple_strtoul(name, &p, 16));
235 if (strcmp(name, "nfs") == 0)
238 if (strcmp(name, "ram") == 0)
241 if (strlen(name) > 31)
247 res = blk_lookup_devt(s, 0);
252 * try non-existent, but valid partition, which may only exist
253 * after revalidating the disk, like partitioned md devices
255 while (p > s && isdigit(p[-1]))
257 if (p == s || !*p || *p == '0')
260 /* try disk name without <part number> */
261 part = simple_strtoul(p, NULL, 10);
263 res = blk_lookup_devt(s, part);
267 /* try disk name without p<part number> */
268 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
271 res = blk_lookup_devt(s, part);
281 static int __init root_dev_setup(char *line)
283 strlcpy(saved_root_name, line, sizeof(saved_root_name));
287 __setup("root=", root_dev_setup);
289 static int __init rootwait_setup(char *str)
297 __setup("rootwait", rootwait_setup);
299 static char * __initdata root_mount_data;
300 static int __init root_data_setup(char *str)
302 root_mount_data = str;
306 static char * __initdata root_fs_names;
307 static int __init fs_names_setup(char *str)
313 static unsigned int __initdata root_delay;
314 static int __init root_delay_setup(char *str)
316 root_delay = simple_strtoul(str, NULL, 0);
320 __setup("rootflags=", root_data_setup);
321 __setup("rootfstype=", fs_names_setup);
322 __setup("rootdelay=", root_delay_setup);
324 static void __init get_fs_names(char *page)
329 strcpy(page, root_fs_names);
335 int len = get_filesystem_list(page);
339 for (p = page-1; p; p = next) {
340 next = strchr(++p, '\n');
343 while ((*s++ = *p++) != '\n')
351 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
353 struct super_block *s;
354 int err = sys_mount(name, "/root", fs, flags, data);
359 s = current->fs->pwd.dentry->d_sb;
362 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
364 s->s_flags & MS_RDONLY ? " readonly" : "",
365 MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
369 void __init mount_block_root(char *name, int flags)
371 struct page *page = alloc_page(GFP_KERNEL |
372 __GFP_NOTRACK_FALSE_POSITIVE);
373 char *fs_names = page_address(page);
376 char b[BDEVNAME_SIZE];
378 const char *b = name;
381 get_fs_names(fs_names);
383 for (p = fs_names; *p; p += strlen(p)+1) {
384 int err = do_mount_root(name, p, flags, root_mount_data);
395 * Allow the user to distinguish between failed sys_open
396 * and bad superblock on root device.
397 * and give them a list of the available devices
400 __bdevname(ROOT_DEV, b);
402 printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
403 root_device_name, b, err);
404 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
406 printk_all_partitions();
407 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
408 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
409 "explicit textual name for \"root=\" boot option.\n");
411 panic("VFS: Unable to mount root fs on %s", b);
414 printk("List of all partitions:\n");
415 printk_all_partitions();
416 printk("No filesystem could mount root, tried: ");
417 for (p = fs_names; *p; p += strlen(p)+1)
421 __bdevname(ROOT_DEV, b);
423 panic("VFS: Unable to mount root fs on %s", b);
428 #ifdef CONFIG_ROOT_NFS
430 #define NFSROOT_TIMEOUT_MIN 5
431 #define NFSROOT_TIMEOUT_MAX 30
432 #define NFSROOT_RETRY_MAX 5
434 static int __init mount_nfs_root(void)
436 char *root_dev, *root_data;
437 unsigned int timeout;
440 err = nfs_root_data(&root_dev, &root_data);
445 * The server or network may not be ready, so try several
446 * times. Stop after a few tries in case the client wants
447 * to fall back to other boot methods.
449 timeout = NFSROOT_TIMEOUT_MIN;
450 for (try = 1; ; try++) {
451 err = do_mount_root(root_dev, "nfs",
452 root_mountflags, root_data);
455 if (try > NFSROOT_RETRY_MAX)
458 /* Wait, in case the server refused us immediately */
461 if (timeout > NFSROOT_TIMEOUT_MAX)
462 timeout = NFSROOT_TIMEOUT_MAX;
468 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
469 void __init change_floppy(char *fmt, ...)
471 struct termios termios;
477 vsprintf(buf, fmt, args);
479 fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
481 sys_ioctl(fd, FDEJECT, 0);
484 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
485 fd = sys_open("/dev/console", O_RDWR, 0);
487 sys_ioctl(fd, TCGETS, (long)&termios);
488 termios.c_lflag &= ~ICANON;
489 sys_ioctl(fd, TCSETSF, (long)&termios);
491 termios.c_lflag |= ICANON;
492 sys_ioctl(fd, TCSETSF, (long)&termios);
498 void __init mount_root(void)
500 #ifdef CONFIG_ROOT_NFS
501 if (ROOT_DEV == Root_NFS) {
502 if (mount_nfs_root())
505 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
509 #ifdef CONFIG_BLK_DEV_FD
510 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
511 /* rd_doload is 2 for a dual initrd/ramload setup */
513 if (rd_load_disk(1)) {
514 ROOT_DEV = Root_RAM1;
515 root_device_name = NULL;
518 change_floppy("root floppy");
522 create_dev("/dev/root", ROOT_DEV);
523 mount_block_root("/dev/root", root_mountflags);
528 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
530 void __init prepare_namespace(void)
535 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
541 * wait for the known devices to complete their probing
543 * Note: this is a potential source of long boot delays.
544 * For example, it is not atypical to wait 5 seconds here
545 * for the touchpad of a laptop to initialize.
547 wait_for_device_probe();
551 if (saved_root_name[0]) {
552 root_device_name = saved_root_name;
553 if (!strncmp(root_device_name, "mtd", 3) ||
554 !strncmp(root_device_name, "ubi", 3)) {
555 mount_block_root(root_device_name, root_mountflags);
558 ROOT_DEV = name_to_dev_t(root_device_name);
559 if (strncmp(root_device_name, "/dev/", 5) == 0)
560 root_device_name += 5;
566 /* wait for any asynchronous scanning to complete */
567 if ((ROOT_DEV == 0) && root_wait) {
568 printk(KERN_INFO "Waiting for root device %s...\n",
570 while (driver_probe_done() != 0 ||
571 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
573 async_synchronize_full();
576 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
578 if (is_floppy && rd_doload && rd_load_disk(0))
579 ROOT_DEV = Root_RAM0;
583 devtmpfs_mount("dev");
584 sys_mount(".", "/", NULL, MS_MOVE, NULL);