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);
73 * match_dev_by_uuid - callback for finding a partition using its uuid
74 * @dev: device passed in by the caller
75 * @data: opaque pointer to a 36 byte char array with a UUID
77 * Returns 1 if the device matches, and 0 otherwise.
79 static int match_dev_by_uuid(struct device *dev, void *data)
82 struct hd_struct *part = dev_to_part(dev);
87 if (memcmp(uuid, part->info->uuid, sizeof(part->info->uuid)))
97 * devt_from_partuuid - looks up the dev_t of a partition by its UUID
98 * @uuid: min 36 byte char array containing a hex ascii UUID
100 * The function will return the first partition which contains a matching
101 * UUID value in its partition_meta_info struct. This does not search
102 * by filesystem UUIDs.
104 * If @uuid is followed by a "/PARTNROFF=%d", then the number will be
105 * extracted and used as an offset from the partition identified by the UUID.
107 * Returns the matching dev_t on success or 0 on failure.
109 static dev_t devt_from_partuuid(char *uuid_str)
112 struct device *dev = NULL;
114 struct gendisk *disk;
115 struct hd_struct *part;
118 if (strlen(uuid_str) < 36)
121 /* Check for optional partition number offset attributes. */
124 /* Explicitly fail on poor PARTUUID syntax. */
125 if (sscanf(&uuid_str[36],
126 "/PARTNROFF=%d%c", &offset, &c) != 1) {
127 printk(KERN_ERR "VFS: PARTUUID= is invalid.\n"
128 "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
131 "Disabling rootwait; root= is invalid.\n");
137 /* Pack the requested UUID in the expected format. */
138 part_pack_uuid(uuid_str, uuid);
140 dev = class_find_device(&block_class, NULL, uuid, &match_dev_by_uuid);
146 /* Attempt to find the partition by offset. */
151 disk = part_to_disk(dev_to_part(dev));
152 part = disk_get_part(disk, dev_to_part(dev)->partno + offset);
154 res = part_devt(part);
155 put_device(part_to_dev(part));
166 * Convert a name into device number. We accept the following variants:
168 * 1) device number in hexadecimal represents itself
169 * 2) /dev/nfs represents Root_NFS (0xff)
170 * 3) /dev/<disk_name> represents the device number of disk
171 * 4) /dev/<disk_name><decimal> represents the device number
172 * of partition - device number of disk plus the partition number
173 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is
174 * used when disk name of partitioned disk ends on a digit.
175 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
176 * unique id of a partition if the partition table provides it.
177 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
178 * a partition with a known unique id.
180 * If name doesn't have fall into the categories above, we return (0,0).
181 * block_class is used to check if something is a disk name. If the disk
182 * name contains slashes, the device name has them replaced with
186 dev_t name_to_dev_t(char *name)
194 if (strncmp(name, "PARTUUID=", 9) == 0) {
196 res = devt_from_partuuid(name);
203 if (strncmp(name, "/dev/", 5) != 0) {
206 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
207 res = MKDEV(maj, min);
208 if (maj != MAJOR(res) || min != MINOR(res))
211 res = new_decode_dev(simple_strtoul(name, &p, 16));
220 if (strcmp(name, "nfs") == 0)
223 if (strcmp(name, "ram") == 0)
226 if (strlen(name) > 31)
232 res = blk_lookup_devt(s, 0);
237 * try non-existent, but valid partition, which may only exist
238 * after revalidating the disk, like partitioned md devices
240 while (p > s && isdigit(p[-1]))
242 if (p == s || !*p || *p == '0')
245 /* try disk name without <part number> */
246 part = simple_strtoul(p, NULL, 10);
248 res = blk_lookup_devt(s, part);
252 /* try disk name without p<part number> */
253 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
256 res = blk_lookup_devt(s, part);
266 static int __init root_dev_setup(char *line)
268 strlcpy(saved_root_name, line, sizeof(saved_root_name));
272 __setup("root=", root_dev_setup);
274 static int __init rootwait_setup(char *str)
282 __setup("rootwait", rootwait_setup);
284 static char * __initdata root_mount_data;
285 static int __init root_data_setup(char *str)
287 root_mount_data = str;
291 static char * __initdata root_fs_names;
292 static int __init fs_names_setup(char *str)
298 static unsigned int __initdata root_delay;
299 static int __init root_delay_setup(char *str)
301 root_delay = simple_strtoul(str, NULL, 0);
305 __setup("rootflags=", root_data_setup);
306 __setup("rootfstype=", fs_names_setup);
307 __setup("rootdelay=", root_delay_setup);
309 static void __init get_fs_names(char *page)
314 strcpy(page, root_fs_names);
320 int len = get_filesystem_list(page);
324 for (p = page-1; p; p = next) {
325 next = strchr(++p, '\n');
328 while ((*s++ = *p++) != '\n')
336 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
338 struct super_block *s;
339 int err = sys_mount(name, "/root", fs, flags, data);
344 s = current->fs->pwd.dentry->d_sb;
347 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
349 s->s_flags & MS_RDONLY ? " readonly" : "",
350 MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
354 void __init mount_block_root(char *name, int flags)
356 struct page *page = alloc_page(GFP_KERNEL |
357 __GFP_NOTRACK_FALSE_POSITIVE);
358 char *fs_names = page_address(page);
361 char b[BDEVNAME_SIZE];
363 const char *b = name;
366 get_fs_names(fs_names);
368 for (p = fs_names; *p; p += strlen(p)+1) {
369 int err = do_mount_root(name, p, flags, root_mount_data);
380 * Allow the user to distinguish between failed sys_open
381 * and bad superblock on root device.
382 * and give them a list of the available devices
385 __bdevname(ROOT_DEV, b);
387 printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
388 root_device_name, b, err);
389 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
391 printk_all_partitions();
392 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
393 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
394 "explicit textual name for \"root=\" boot option.\n");
396 panic("VFS: Unable to mount root fs on %s", b);
399 printk("List of all partitions:\n");
400 printk_all_partitions();
401 printk("No filesystem could mount root, tried: ");
402 for (p = fs_names; *p; p += strlen(p)+1)
406 __bdevname(ROOT_DEV, b);
408 panic("VFS: Unable to mount root fs on %s", b);
413 #ifdef CONFIG_ROOT_NFS
415 #define NFSROOT_TIMEOUT_MIN 5
416 #define NFSROOT_TIMEOUT_MAX 30
417 #define NFSROOT_RETRY_MAX 5
419 static int __init mount_nfs_root(void)
421 char *root_dev, *root_data;
422 unsigned int timeout;
425 err = nfs_root_data(&root_dev, &root_data);
430 * The server or network may not be ready, so try several
431 * times. Stop after a few tries in case the client wants
432 * to fall back to other boot methods.
434 timeout = NFSROOT_TIMEOUT_MIN;
435 for (try = 1; ; try++) {
436 err = do_mount_root(root_dev, "nfs",
437 root_mountflags, root_data);
440 if (try > NFSROOT_RETRY_MAX)
443 /* Wait, in case the server refused us immediately */
446 if (timeout > NFSROOT_TIMEOUT_MAX)
447 timeout = NFSROOT_TIMEOUT_MAX;
453 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
454 void __init change_floppy(char *fmt, ...)
456 struct termios termios;
462 vsprintf(buf, fmt, args);
464 fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
466 sys_ioctl(fd, FDEJECT, 0);
469 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
470 fd = sys_open("/dev/console", O_RDWR, 0);
472 sys_ioctl(fd, TCGETS, (long)&termios);
473 termios.c_lflag &= ~ICANON;
474 sys_ioctl(fd, TCSETSF, (long)&termios);
476 termios.c_lflag |= ICANON;
477 sys_ioctl(fd, TCSETSF, (long)&termios);
483 void __init mount_root(void)
485 #ifdef CONFIG_ROOT_NFS
486 if (ROOT_DEV == Root_NFS) {
487 if (mount_nfs_root())
490 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
494 #ifdef CONFIG_BLK_DEV_FD
495 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
496 /* rd_doload is 2 for a dual initrd/ramload setup */
498 if (rd_load_disk(1)) {
499 ROOT_DEV = Root_RAM1;
500 root_device_name = NULL;
503 change_floppy("root floppy");
507 create_dev("/dev/root", ROOT_DEV);
508 mount_block_root("/dev/root", root_mountflags);
513 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
515 void __init prepare_namespace(void)
520 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
526 * wait for the known devices to complete their probing
528 * Note: this is a potential source of long boot delays.
529 * For example, it is not atypical to wait 5 seconds here
530 * for the touchpad of a laptop to initialize.
532 wait_for_device_probe();
536 if (saved_root_name[0]) {
537 root_device_name = saved_root_name;
538 if (!strncmp(root_device_name, "mtd", 3) ||
539 !strncmp(root_device_name, "ubi", 3)) {
540 mount_block_root(root_device_name, root_mountflags);
543 ROOT_DEV = name_to_dev_t(root_device_name);
544 if (strncmp(root_device_name, "/dev/", 5) == 0)
545 root_device_name += 5;
551 /* wait for any asynchronous scanning to complete */
552 if ((ROOT_DEV == 0) && root_wait) {
553 printk(KERN_INFO "Waiting for root device %s...\n",
555 while (driver_probe_done() != 0 ||
556 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
558 async_synchronize_full();
561 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
563 if (is_floppy && rd_doload && rd_load_disk(0))
564 ROOT_DEV = Root_RAM0;
568 devtmpfs_mount("dev");
569 sys_mount(".", "/", NULL, MS_MOVE, NULL);