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![Florin Malita](/assets/img/avatar_default.png)
The ROOT_DEV comment is no longer accurate, it now seems to be initialized in init/do_mounts.c. Signed-off-by: Florin Malita <fmalita@gmail.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
428 lines
9 KiB
C
428 lines
9 KiB
C
#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/ctype.h>
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#include <linux/fd.h>
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#include <linux/tty.h>
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#include <linux/suspend.h>
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#include <linux/root_dev.h>
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#include <linux/security.h>
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#include <linux/delay.h>
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#include <linux/mount.h>
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#include <linux/nfs_fs.h>
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#include <linux/nfs_fs_sb.h>
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#include <linux/nfs_mount.h>
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#include "do_mounts.h"
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extern int get_filesystem_list(char * buf);
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int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
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int root_mountflags = MS_RDONLY | MS_SILENT;
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char * __initdata root_device_name;
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static char __initdata saved_root_name[64];
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dev_t ROOT_DEV;
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static int __init load_ramdisk(char *str)
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{
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rd_doload = simple_strtol(str,NULL,0) & 3;
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return 1;
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}
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__setup("load_ramdisk=", load_ramdisk);
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static int __init readonly(char *str)
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{
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if (*str)
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return 0;
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root_mountflags |= MS_RDONLY;
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return 1;
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}
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static int __init readwrite(char *str)
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{
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if (*str)
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return 0;
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root_mountflags &= ~MS_RDONLY;
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return 1;
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}
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__setup("ro", readonly);
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__setup("rw", readwrite);
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static dev_t try_name(char *name, int part)
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{
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char path[64];
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char buf[32];
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int range;
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dev_t res;
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char *s;
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int len;
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int fd;
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unsigned int maj, min;
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/* read device number from .../dev */
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sprintf(path, "/sys/block/%s/dev", name);
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fd = sys_open(path, 0, 0);
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if (fd < 0)
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goto fail;
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len = sys_read(fd, buf, 32);
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sys_close(fd);
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if (len <= 0 || len == 32 || buf[len - 1] != '\n')
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goto fail;
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buf[len - 1] = '\0';
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if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
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/*
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* Try the %u:%u format -- see print_dev_t()
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*/
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res = MKDEV(maj, min);
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if (maj != MAJOR(res) || min != MINOR(res))
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goto fail;
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} else {
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/*
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* Nope. Try old-style "0321"
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*/
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res = new_decode_dev(simple_strtoul(buf, &s, 16));
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if (*s)
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goto fail;
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}
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/* if it's there and we are not looking for a partition - that's it */
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if (!part)
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return res;
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/* otherwise read range from .../range */
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sprintf(path, "/sys/block/%s/range", name);
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fd = sys_open(path, 0, 0);
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if (fd < 0)
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goto fail;
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len = sys_read(fd, buf, 32);
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sys_close(fd);
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if (len <= 0 || len == 32 || buf[len - 1] != '\n')
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goto fail;
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buf[len - 1] = '\0';
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range = simple_strtoul(buf, &s, 10);
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if (*s)
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goto fail;
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/* if partition is within range - we got it */
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if (part < range)
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return res + part;
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fail:
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return 0;
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}
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/*
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* Convert a name into device number. We accept the following variants:
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*
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* 1) device number in hexadecimal represents itself
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* 2) /dev/nfs represents Root_NFS (0xff)
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* 3) /dev/<disk_name> represents the device number of disk
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* 4) /dev/<disk_name><decimal> represents the device number
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* of partition - device number of disk plus the partition number
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* 5) /dev/<disk_name>p<decimal> - same as the above, that form is
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* used when disk name of partitioned disk ends on a digit.
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*
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* If name doesn't have fall into the categories above, we return 0.
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* Sysfs is used to check if something is a disk name - it has
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* all known disks under bus/block/devices. If the disk name
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* contains slashes, name of sysfs node has them replaced with
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* bangs. try_name() does the actual checks, assuming that sysfs
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* is mounted on rootfs /sys.
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*/
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dev_t name_to_dev_t(char *name)
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{
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char s[32];
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char *p;
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dev_t res = 0;
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int part;
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#ifdef CONFIG_SYSFS
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int mkdir_err = sys_mkdir("/sys", 0700);
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if (sys_mount("sysfs", "/sys", "sysfs", 0, NULL) < 0)
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goto out;
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#endif
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if (strncmp(name, "/dev/", 5) != 0) {
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unsigned maj, min;
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if (sscanf(name, "%u:%u", &maj, &min) == 2) {
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res = MKDEV(maj, min);
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if (maj != MAJOR(res) || min != MINOR(res))
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goto fail;
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} else {
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res = new_decode_dev(simple_strtoul(name, &p, 16));
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if (*p)
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goto fail;
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}
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goto done;
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}
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name += 5;
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res = Root_NFS;
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if (strcmp(name, "nfs") == 0)
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goto done;
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res = Root_RAM0;
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if (strcmp(name, "ram") == 0)
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goto done;
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if (strlen(name) > 31)
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goto fail;
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strcpy(s, name);
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for (p = s; *p; p++)
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if (*p == '/')
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*p = '!';
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res = try_name(s, 0);
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if (res)
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goto done;
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while (p > s && isdigit(p[-1]))
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p--;
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if (p == s || !*p || *p == '0')
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goto fail;
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part = simple_strtoul(p, NULL, 10);
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*p = '\0';
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res = try_name(s, part);
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if (res)
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goto done;
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if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
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goto fail;
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p[-1] = '\0';
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res = try_name(s, part);
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done:
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#ifdef CONFIG_SYSFS
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sys_umount("/sys", 0);
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out:
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if (!mkdir_err)
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sys_rmdir("/sys");
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#endif
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return res;
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fail:
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res = 0;
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goto done;
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}
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static int __init root_dev_setup(char *line)
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{
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strlcpy(saved_root_name, line, sizeof(saved_root_name));
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return 1;
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}
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__setup("root=", root_dev_setup);
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static char * __initdata root_mount_data;
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static int __init root_data_setup(char *str)
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{
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root_mount_data = str;
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return 1;
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}
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static char * __initdata root_fs_names;
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static int __init fs_names_setup(char *str)
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{
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root_fs_names = str;
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return 1;
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}
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static unsigned int __initdata root_delay;
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static int __init root_delay_setup(char *str)
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{
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root_delay = simple_strtoul(str, NULL, 0);
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return 1;
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}
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__setup("rootflags=", root_data_setup);
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__setup("rootfstype=", fs_names_setup);
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__setup("rootdelay=", root_delay_setup);
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static void __init get_fs_names(char *page)
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{
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char *s = page;
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if (root_fs_names) {
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strcpy(page, root_fs_names);
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while (*s++) {
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if (s[-1] == ',')
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s[-1] = '\0';
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}
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} else {
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int len = get_filesystem_list(page);
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char *p, *next;
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page[len] = '\0';
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for (p = page-1; p; p = next) {
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next = strchr(++p, '\n');
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if (*p++ != '\t')
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continue;
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while ((*s++ = *p++) != '\n')
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;
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s[-1] = '\0';
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}
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}
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*s = '\0';
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}
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static int __init do_mount_root(char *name, char *fs, int flags, void *data)
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{
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int err = sys_mount(name, "/root", fs, flags, data);
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if (err)
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return err;
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sys_chdir("/root");
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ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
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printk("VFS: Mounted root (%s filesystem)%s.\n",
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current->fs->pwdmnt->mnt_sb->s_type->name,
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current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
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" readonly" : "");
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return 0;
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}
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void __init mount_block_root(char *name, int flags)
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{
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char *fs_names = __getname();
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char *p;
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char b[BDEVNAME_SIZE];
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get_fs_names(fs_names);
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retry:
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for (p = fs_names; *p; p += strlen(p)+1) {
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int err = do_mount_root(name, p, flags, root_mount_data);
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switch (err) {
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case 0:
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goto out;
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case -EACCES:
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flags |= MS_RDONLY;
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goto retry;
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case -EINVAL:
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continue;
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}
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/*
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* Allow the user to distinguish between failed sys_open
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* and bad superblock on root device.
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*/
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__bdevname(ROOT_DEV, b);
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printk("VFS: Cannot open root device \"%s\" or %s\n",
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root_device_name, b);
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printk("Please append a correct \"root=\" boot option\n");
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panic("VFS: Unable to mount root fs on %s", b);
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}
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panic("VFS: Unable to mount root fs on %s", __bdevname(ROOT_DEV, b));
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out:
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putname(fs_names);
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}
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#ifdef CONFIG_ROOT_NFS
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static int __init mount_nfs_root(void)
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{
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void *data = nfs_root_data();
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create_dev("/dev/root", ROOT_DEV, NULL);
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if (data &&
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do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
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return 1;
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return 0;
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}
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#endif
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#if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
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void __init change_floppy(char *fmt, ...)
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{
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struct termios termios;
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char buf[80];
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char c;
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int fd;
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va_list args;
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va_start(args, fmt);
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vsprintf(buf, fmt, args);
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va_end(args);
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fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
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if (fd >= 0) {
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sys_ioctl(fd, FDEJECT, 0);
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sys_close(fd);
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}
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printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
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fd = sys_open("/dev/console", O_RDWR, 0);
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if (fd >= 0) {
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sys_ioctl(fd, TCGETS, (long)&termios);
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termios.c_lflag &= ~ICANON;
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sys_ioctl(fd, TCSETSF, (long)&termios);
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sys_read(fd, &c, 1);
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termios.c_lflag |= ICANON;
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sys_ioctl(fd, TCSETSF, (long)&termios);
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sys_close(fd);
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}
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}
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#endif
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void __init mount_root(void)
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{
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#ifdef CONFIG_ROOT_NFS
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if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
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if (mount_nfs_root())
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return;
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printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
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ROOT_DEV = Root_FD0;
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}
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#endif
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#ifdef CONFIG_BLK_DEV_FD
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if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
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/* rd_doload is 2 for a dual initrd/ramload setup */
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if (rd_doload==2) {
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if (rd_load_disk(1)) {
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ROOT_DEV = Root_RAM1;
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root_device_name = NULL;
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}
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} else
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change_floppy("root floppy");
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}
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#endif
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create_dev("/dev/root", ROOT_DEV, root_device_name);
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mount_block_root("/dev/root", root_mountflags);
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}
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/*
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* Prepare the namespace - decide what/where to mount, load ramdisks, etc.
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*/
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void __init prepare_namespace(void)
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{
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int is_floppy;
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mount_devfs();
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if (root_delay) {
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printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
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root_delay);
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ssleep(root_delay);
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}
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md_run_setup();
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if (saved_root_name[0]) {
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root_device_name = saved_root_name;
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ROOT_DEV = name_to_dev_t(root_device_name);
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if (strncmp(root_device_name, "/dev/", 5) == 0)
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root_device_name += 5;
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}
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is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
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if (initrd_load())
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goto out;
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if (is_floppy && rd_doload && rd_load_disk(0))
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ROOT_DEV = Root_RAM0;
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mount_root();
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out:
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umount_devfs("/dev");
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sys_mount(".", "/", NULL, MS_MOVE, NULL);
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sys_chroot(".");
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security_sb_post_mountroot();
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mount_devfs_fs ();
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}
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