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
);
62 * match_dev_by_uuid - callback for finding a partition using its uuid
63 * @dev: device passed in by the caller
64 * @data: opaque pointer to a 36 byte char array with a UUID
66 * Returns 1 if the device matches, and 0 otherwise.
68 static int __init
match_dev_by_uuid(struct device
*dev
, void *data
)
71 struct hd_struct
*part
= dev_to_part(dev
);
76 if (memcmp(uuid
, part
->info
->uuid
, sizeof(part
->info
->uuid
)))
86 * devt_from_partuuid - looks up the dev_t of a partition by its UUID
87 * @uuid: 36 byte char array containing a hex ascii UUID
89 * The function will return the first partition which contains a matching
90 * UUID value in its partition_meta_info struct. This does not search
91 * by filesystem UUIDs.
93 * Returns the matching dev_t on success or 0 on failure.
95 static dev_t __init
devt_from_partuuid(char *uuid_str
)
98 struct device
*dev
= NULL
;
101 /* Pack the requested UUID in the expected format. */
102 part_pack_uuid(uuid_str
, uuid
);
104 dev
= class_find_device(&block_class
, NULL
, uuid
, &match_dev_by_uuid
);
116 * Convert a name into device number. We accept the following variants:
118 * 1) device number in hexadecimal represents itself
119 * 2) /dev/nfs represents Root_NFS (0xff)
120 * 3) /dev/<disk_name> represents the device number of disk
121 * 4) /dev/<disk_name><decimal> represents the device number
122 * of partition - device number of disk plus the partition number
123 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is
124 * used when disk name of partitioned disk ends on a digit.
125 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
126 * unique id of a partition if the partition table provides it.
128 * If name doesn't have fall into the categories above, we return (0,0).
129 * block_class is used to check if something is a disk name. If the disk
130 * name contains slashes, the device name has them replaced with
134 dev_t
name_to_dev_t(char *name
)
141 if (strncmp(name
, "PARTUUID=", 9) == 0) {
143 if (strlen(name
) != 36)
145 res
= devt_from_partuuid(name
);
151 if (strncmp(name
, "/dev/", 5) != 0) {
154 if (sscanf(name
, "%u:%u", &maj
, &min
) == 2) {
155 res
= MKDEV(maj
, min
);
156 if (maj
!= MAJOR(res
) || min
!= MINOR(res
))
159 res
= new_decode_dev(simple_strtoul(name
, &p
, 16));
168 if (strcmp(name
, "nfs") == 0)
171 if (strcmp(name
, "ram") == 0)
174 if (strlen(name
) > 31)
180 res
= blk_lookup_devt(s
, 0);
185 * try non-existant, but valid partition, which may only exist
186 * after revalidating the disk, like partitioned md devices
188 while (p
> s
&& isdigit(p
[-1]))
190 if (p
== s
|| !*p
|| *p
== '0')
193 /* try disk name without <part number> */
194 part
= simple_strtoul(p
, NULL
, 10);
196 res
= blk_lookup_devt(s
, part
);
200 /* try disk name without p<part number> */
201 if (p
< s
+ 2 || !isdigit(p
[-2]) || p
[-1] != 'p')
204 res
= blk_lookup_devt(s
, part
);
214 static int __init
root_dev_setup(char *line
)
216 strlcpy(saved_root_name
, line
, sizeof(saved_root_name
));
220 __setup("root=", root_dev_setup
);
222 static int __init
rootwait_setup(char *str
)
230 __setup("rootwait", rootwait_setup
);
232 static char * __initdata root_mount_data
;
233 static int __init
root_data_setup(char *str
)
235 root_mount_data
= str
;
239 static char * __initdata root_fs_names
;
240 static int __init
fs_names_setup(char *str
)
246 static unsigned int __initdata root_delay
;
247 static int __init
root_delay_setup(char *str
)
249 root_delay
= simple_strtoul(str
, NULL
, 0);
253 __setup("rootflags=", root_data_setup
);
254 __setup("rootfstype=", fs_names_setup
);
255 __setup("rootdelay=", root_delay_setup
);
257 static void __init
get_fs_names(char *page
)
262 strcpy(page
, root_fs_names
);
268 int len
= get_filesystem_list(page
);
272 for (p
= page
-1; p
; p
= next
) {
273 next
= strchr(++p
, '\n');
276 while ((*s
++ = *p
++) != '\n')
284 static int __init
do_mount_root(char *name
, char *fs
, int flags
, void *data
)
286 int err
= sys_mount(name
, "/root", fs
, flags
, data
);
291 ROOT_DEV
= current
->fs
->pwd
.mnt
->mnt_sb
->s_dev
;
292 printk("VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
293 current
->fs
->pwd
.mnt
->mnt_sb
->s_type
->name
,
294 current
->fs
->pwd
.mnt
->mnt_sb
->s_flags
& MS_RDONLY
?
295 " readonly" : "", MAJOR(ROOT_DEV
), MINOR(ROOT_DEV
));
299 void __init
mount_block_root(char *name
, int flags
)
301 char *fs_names
= __getname_gfp(GFP_KERNEL
302 | __GFP_NOTRACK_FALSE_POSITIVE
);
305 char b
[BDEVNAME_SIZE
];
307 const char *b
= name
;
310 get_fs_names(fs_names
);
312 for (p
= fs_names
; *p
; p
+= strlen(p
)+1) {
313 int err
= do_mount_root(name
, p
, flags
, root_mount_data
);
324 * Allow the user to distinguish between failed sys_open
325 * and bad superblock on root device.
326 * and give them a list of the available devices
329 __bdevname(ROOT_DEV
, b
);
331 printk("VFS: Cannot open root device \"%s\" or %s\n",
332 root_device_name
, b
);
333 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
335 printk_all_partitions();
336 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
337 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
338 "explicit textual name for \"root=\" boot option.\n");
340 panic("VFS: Unable to mount root fs on %s", b
);
343 printk("List of all partitions:\n");
344 printk_all_partitions();
345 printk("No filesystem could mount root, tried: ");
346 for (p
= fs_names
; *p
; p
+= strlen(p
)+1)
350 __bdevname(ROOT_DEV
, b
);
352 panic("VFS: Unable to mount root fs on %s", b
);
357 #ifdef CONFIG_ROOT_NFS
358 static int __init
mount_nfs_root(void)
360 void *data
= nfs_root_data();
362 create_dev("/dev/root", ROOT_DEV
);
364 do_mount_root("/dev/root", "nfs", root_mountflags
, data
) == 0)
370 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
371 void __init
change_floppy(char *fmt
, ...)
373 struct termios termios
;
379 vsprintf(buf
, fmt
, args
);
381 fd
= sys_open("/dev/root", O_RDWR
| O_NDELAY
, 0);
383 sys_ioctl(fd
, FDEJECT
, 0);
386 printk(KERN_NOTICE
"VFS: Insert %s and press ENTER\n", buf
);
387 fd
= sys_open("/dev/console", O_RDWR
, 0);
389 sys_ioctl(fd
, TCGETS
, (long)&termios
);
390 termios
.c_lflag
&= ~ICANON
;
391 sys_ioctl(fd
, TCSETSF
, (long)&termios
);
393 termios
.c_lflag
|= ICANON
;
394 sys_ioctl(fd
, TCSETSF
, (long)&termios
);
400 void __init
mount_root(void)
402 #ifdef CONFIG_ROOT_NFS
403 if (MAJOR(ROOT_DEV
) == UNNAMED_MAJOR
) {
404 if (mount_nfs_root())
407 printk(KERN_ERR
"VFS: Unable to mount root fs via NFS, trying floppy.\n");
411 #ifdef CONFIG_BLK_DEV_FD
412 if (MAJOR(ROOT_DEV
) == FLOPPY_MAJOR
) {
413 /* rd_doload is 2 for a dual initrd/ramload setup */
415 if (rd_load_disk(1)) {
416 ROOT_DEV
= Root_RAM1
;
417 root_device_name
= NULL
;
420 change_floppy("root floppy");
424 create_dev("/dev/root", ROOT_DEV
);
425 mount_block_root("/dev/root", root_mountflags
);
430 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
432 void __init
prepare_namespace(void)
437 printk(KERN_INFO
"Waiting %dsec before mounting root device...\n",
443 * wait for the known devices to complete their probing
445 * Note: this is a potential source of long boot delays.
446 * For example, it is not atypical to wait 5 seconds here
447 * for the touchpad of a laptop to initialize.
449 wait_for_device_probe();
453 if (saved_root_name
[0]) {
454 root_device_name
= saved_root_name
;
455 if (!strncmp(root_device_name
, "mtd", 3) ||
456 !strncmp(root_device_name
, "ubi", 3)) {
457 mount_block_root(root_device_name
, root_mountflags
);
460 ROOT_DEV
= name_to_dev_t(root_device_name
);
461 if (strncmp(root_device_name
, "/dev/", 5) == 0)
462 root_device_name
+= 5;
468 /* wait for any asynchronous scanning to complete */
469 if ((ROOT_DEV
== 0) && root_wait
) {
470 printk(KERN_INFO
"Waiting for root device %s...\n",
472 while (driver_probe_done() != 0 ||
473 (ROOT_DEV
= name_to_dev_t(saved_root_name
)) == 0)
475 async_synchronize_full();
478 is_floppy
= MAJOR(ROOT_DEV
) == FLOPPY_MAJOR
;
480 if (is_floppy
&& rd_doload
&& rd_load_disk(0))
481 ROOT_DEV
= Root_RAM0
;
485 devtmpfs_mount("dev");
486 sys_mount(".", "/", NULL
, MS_MOVE
, NULL
);