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 * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS
193 * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero-
194 * filled hex representation of the 32-bit "NT disk signature", and PP
195 * is a zero-filled hex representation of the 1-based partition number.
196 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
197 * a partition with a known unique id.
199 * If name doesn't have fall into the categories above, we return (0,0).
200 * block_class is used to check if something is a disk name. If the disk
201 * name contains slashes, the device name has them replaced with
205 dev_t name_to_dev_t(char *name)
213 if (strncmp(name, "PARTUUID=", 9) == 0) {
215 res = devt_from_partuuid(name);
222 if (strncmp(name, "/dev/", 5) != 0) {
225 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
226 res = MKDEV(maj, min);
227 if (maj != MAJOR(res) || min != MINOR(res))
230 res = new_decode_dev(simple_strtoul(name, &p, 16));
239 if (strcmp(name, "nfs") == 0)
242 if (strcmp(name, "ram") == 0)
245 if (strlen(name) > 31)
251 res = blk_lookup_devt(s, 0);
256 * try non-existent, but valid partition, which may only exist
257 * after revalidating the disk, like partitioned md devices
259 while (p > s && isdigit(p[-1]))
261 if (p == s || !*p || *p == '0')
264 /* try disk name without <part number> */
265 part = simple_strtoul(p, NULL, 10);
267 res = blk_lookup_devt(s, part);
271 /* try disk name without p<part number> */
272 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
275 res = blk_lookup_devt(s, part);
285 static int __init root_dev_setup(char *line)
287 strlcpy(saved_root_name, line, sizeof(saved_root_name));
291 __setup("root=", root_dev_setup);
293 static int __init rootwait_setup(char *str)
301 __setup("rootwait", rootwait_setup);
303 static char * __initdata root_mount_data;
304 static int __init root_data_setup(char *str)
306 root_mount_data = str;
310 static char * __initdata root_fs_names;
311 static int __init fs_names_setup(char *str)
317 static unsigned int __initdata root_delay;
318 static int __init root_delay_setup(char *str)
320 root_delay = simple_strtoul(str, NULL, 0);
324 __setup("rootflags=", root_data_setup);
325 __setup("rootfstype=", fs_names_setup);
326 __setup("rootdelay=", root_delay_setup);
328 static void __init get_fs_names(char *page)
333 strcpy(page, root_fs_names);
339 int len = get_filesystem_list(page);
343 for (p = page-1; p; p = next) {
344 next = strchr(++p, '\n');
347 while ((*s++ = *p++) != '\n')
355 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
357 struct super_block *s;
358 int err = sys_mount(name, "/root", fs, flags, data);
363 s = current->fs->pwd.dentry->d_sb;
366 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
368 s->s_flags & MS_RDONLY ? " readonly" : "",
369 MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
373 void __init mount_block_root(char *name, int flags)
375 struct page *page = alloc_page(GFP_KERNEL |
376 __GFP_NOTRACK_FALSE_POSITIVE);
377 char *fs_names = page_address(page);
380 char b[BDEVNAME_SIZE];
382 const char *b = name;
385 get_fs_names(fs_names);
387 for (p = fs_names; *p; p += strlen(p)+1) {
388 int err = do_mount_root(name, p, flags, root_mount_data);
399 * Allow the user to distinguish between failed sys_open
400 * and bad superblock on root device.
401 * and give them a list of the available devices
404 __bdevname(ROOT_DEV, b);
406 printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
407 root_device_name, b, err);
408 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
410 printk_all_partitions();
411 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
412 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
413 "explicit textual name for \"root=\" boot option.\n");
415 panic("VFS: Unable to mount root fs on %s", b);
418 printk("List of all partitions:\n");
419 printk_all_partitions();
420 printk("No filesystem could mount root, tried: ");
421 for (p = fs_names; *p; p += strlen(p)+1)
425 __bdevname(ROOT_DEV, b);
427 panic("VFS: Unable to mount root fs on %s", b);
432 #ifdef CONFIG_ROOT_NFS
434 #define NFSROOT_TIMEOUT_MIN 5
435 #define NFSROOT_TIMEOUT_MAX 30
436 #define NFSROOT_RETRY_MAX 5
438 static int __init mount_nfs_root(void)
440 char *root_dev, *root_data;
441 unsigned int timeout;
444 err = nfs_root_data(&root_dev, &root_data);
449 * The server or network may not be ready, so try several
450 * times. Stop after a few tries in case the client wants
451 * to fall back to other boot methods.
453 timeout = NFSROOT_TIMEOUT_MIN;
454 for (try = 1; ; try++) {
455 err = do_mount_root(root_dev, "nfs",
456 root_mountflags, root_data);
459 if (try > NFSROOT_RETRY_MAX)
462 /* Wait, in case the server refused us immediately */
465 if (timeout > NFSROOT_TIMEOUT_MAX)
466 timeout = NFSROOT_TIMEOUT_MAX;
472 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
473 void __init change_floppy(char *fmt, ...)
475 struct termios termios;
481 vsprintf(buf, fmt, args);
483 fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
485 sys_ioctl(fd, FDEJECT, 0);
488 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
489 fd = sys_open("/dev/console", O_RDWR, 0);
491 sys_ioctl(fd, TCGETS, (long)&termios);
492 termios.c_lflag &= ~ICANON;
493 sys_ioctl(fd, TCSETSF, (long)&termios);
495 termios.c_lflag |= ICANON;
496 sys_ioctl(fd, TCSETSF, (long)&termios);
502 void __init mount_root(void)
504 #ifdef CONFIG_ROOT_NFS
505 if (ROOT_DEV == Root_NFS) {
506 if (mount_nfs_root())
509 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
513 #ifdef CONFIG_BLK_DEV_FD
514 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
515 /* rd_doload is 2 for a dual initrd/ramload setup */
517 if (rd_load_disk(1)) {
518 ROOT_DEV = Root_RAM1;
519 root_device_name = NULL;
522 change_floppy("root floppy");
526 create_dev("/dev/root", ROOT_DEV);
527 mount_block_root("/dev/root", root_mountflags);
532 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
534 void __init prepare_namespace(void)
539 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
545 * wait for the known devices to complete their probing
547 * Note: this is a potential source of long boot delays.
548 * For example, it is not atypical to wait 5 seconds here
549 * for the touchpad of a laptop to initialize.
551 wait_for_device_probe();
555 if (saved_root_name[0]) {
556 root_device_name = saved_root_name;
557 if (!strncmp(root_device_name, "mtd", 3) ||
558 !strncmp(root_device_name, "ubi", 3)) {
559 mount_block_root(root_device_name, root_mountflags);
562 ROOT_DEV = name_to_dev_t(root_device_name);
563 if (strncmp(root_device_name, "/dev/", 5) == 0)
564 root_device_name += 5;
570 /* wait for any asynchronous scanning to complete */
571 if ((ROOT_DEV == 0) && root_wait) {
572 printk(KERN_INFO "Waiting for root device %s...\n",
574 while (driver_probe_done() != 0 ||
575 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
577 async_synchronize_full();
580 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
582 if (is_floppy && rd_doload && rd_load_disk(0))
583 ROOT_DEV = Root_RAM0;
587 devtmpfs_mount("dev");
588 sys_mount(".", "/", NULL, MS_MOVE, NULL);