638 lines
14 KiB
C
638 lines
14 KiB
C
/*
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* Many of the syscalls used in this file expect some of the arguments
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* to be __user pointers not __kernel pointers. To limit the sparse
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* noise, turn off sparse checking for this file.
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*/
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#ifdef __CHECKER__
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#undef __CHECKER__
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#warning "Sparse checking disabled for this file"
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#endif
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#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/genhd.h>
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#include <linux/mount.h>
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/initrd.h>
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#include <linux/async.h>
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#include <linux/fs_struct.h>
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#include <linux/slab.h>
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#include <linux/ramfs.h>
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#include <linux/shmem_fs.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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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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static char * __initdata root_device_name;
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static char __initdata saved_root_name[64];
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static int root_wait;
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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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#ifdef CONFIG_BLOCK
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struct uuidcmp {
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const char *uuid;
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int len;
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};
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/**
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* match_dev_by_uuid - callback for finding a partition using its uuid
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* @dev: device passed in by the caller
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* @data: opaque pointer to the desired struct uuidcmp to match
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*
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* Returns 1 if the device matches, and 0 otherwise.
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*/
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static int match_dev_by_uuid(struct device *dev, const void *data)
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{
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const struct uuidcmp *cmp = data;
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struct hd_struct *part = dev_to_part(dev);
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if (!part->info)
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goto no_match;
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if (strncasecmp(cmp->uuid, part->info->uuid, cmp->len))
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goto no_match;
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return 1;
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no_match:
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return 0;
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}
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/**
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* devt_from_partuuid - looks up the dev_t of a partition by its UUID
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* @uuid: char array containing ascii UUID
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*
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* The function will return the first partition which contains a matching
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* UUID value in its partition_meta_info struct. This does not search
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* by filesystem UUIDs.
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*
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* If @uuid is followed by a "/PARTNROFF=%d", then the number will be
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* extracted and used as an offset from the partition identified by the UUID.
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*
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* Returns the matching dev_t on success or 0 on failure.
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*/
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static dev_t devt_from_partuuid(const char *uuid_str)
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{
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dev_t res = 0;
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struct uuidcmp cmp;
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struct device *dev = NULL;
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struct gendisk *disk;
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struct hd_struct *part;
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int offset = 0;
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bool clear_root_wait = false;
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char *slash;
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cmp.uuid = uuid_str;
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slash = strchr(uuid_str, '/');
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/* Check for optional partition number offset attributes. */
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if (slash) {
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char c = 0;
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/* Explicitly fail on poor PARTUUID syntax. */
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if (sscanf(slash + 1,
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"PARTNROFF=%d%c", &offset, &c) != 1) {
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clear_root_wait = true;
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goto done;
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}
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cmp.len = slash - uuid_str;
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} else {
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cmp.len = strlen(uuid_str);
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}
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if (!cmp.len) {
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clear_root_wait = true;
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goto done;
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}
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dev = class_find_device(&block_class, NULL, &cmp,
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&match_dev_by_uuid);
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if (!dev)
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goto done;
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res = dev->devt;
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/* Attempt to find the partition by offset. */
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if (!offset)
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goto no_offset;
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res = 0;
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disk = part_to_disk(dev_to_part(dev));
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part = disk_get_part(disk, dev_to_part(dev)->partno + offset);
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if (part) {
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res = part_devt(part);
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put_device(part_to_dev(part));
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}
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no_offset:
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put_device(dev);
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done:
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if (clear_root_wait) {
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pr_err("VFS: PARTUUID= is invalid.\n"
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"Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
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if (root_wait)
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pr_err("Disabling rootwait; root= is invalid.\n");
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root_wait = 0;
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}
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return res;
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}
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#endif
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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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* 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
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* unique id of a partition if the partition table provides it.
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* The UUID may be either an EFI/GPT UUID, or refer to an MSDOS
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* partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero-
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* filled hex representation of the 32-bit "NT disk signature", and PP
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* is a zero-filled hex representation of the 1-based partition number.
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* 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
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* a partition with a known unique id.
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* 8) <major>:<minor> major and minor number of the device separated by
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* a colon.
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*
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* If name doesn't have fall into the categories above, we return (0,0).
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* block_class is used to check if something is a disk name. If the disk
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* name contains slashes, the device name has them replaced with
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* bangs.
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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_BLOCK
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if (strncmp(name, "PARTUUID=", 9) == 0) {
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name += 9;
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res = devt_from_partuuid(name);
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if (!res)
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goto fail;
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goto done;
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}
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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 = blk_lookup_devt(s, 0);
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if (res)
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goto done;
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/*
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* try non-existent, but valid partition, which may only exist
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* after revalidating the disk, like partitioned md devices
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*/
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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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/* try disk name without <part number> */
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part = simple_strtoul(p, NULL, 10);
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*p = '\0';
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res = blk_lookup_devt(s, part);
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if (res)
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goto done;
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/* try disk name without p<part number> */
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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 = blk_lookup_devt(s, part);
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if (res)
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goto done;
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fail:
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return 0;
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done:
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return res;
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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 int __init rootwait_setup(char *str)
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{
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if (*str)
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return 0;
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root_wait = 1;
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return 1;
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}
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__setup("rootwait", rootwait_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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struct super_block *s;
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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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s = current->fs->pwd.dentry->d_sb;
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ROOT_DEV = s->s_dev;
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printk(KERN_INFO
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"VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
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s->s_type->name,
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s->s_flags & MS_RDONLY ? " readonly" : "",
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MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
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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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struct page *page = alloc_page(GFP_KERNEL |
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__GFP_NOTRACK_FALSE_POSITIVE);
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char *fs_names = page_address(page);
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char *p;
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#ifdef CONFIG_BLOCK
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char b[BDEVNAME_SIZE];
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#else
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const char *b = name;
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#endif
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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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* and give them a list of the available devices
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*/
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#ifdef CONFIG_BLOCK
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__bdevname(ROOT_DEV, b);
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#endif
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printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
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root_device_name, b, err);
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printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
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printk_all_partitions();
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#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
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printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
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"explicit textual name for \"root=\" boot option.\n");
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#endif
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panic("VFS: Unable to mount root fs on %s", b);
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}
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printk("List of all partitions:\n");
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printk_all_partitions();
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printk("No filesystem could mount root, tried: ");
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for (p = fs_names; *p; p += strlen(p)+1)
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printk(" %s", p);
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printk("\n");
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#ifdef CONFIG_BLOCK
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__bdevname(ROOT_DEV, b);
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#endif
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panic("VFS: Unable to mount root fs on %s", b);
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out:
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put_page(page);
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}
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#ifdef CONFIG_ROOT_NFS
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#define NFSROOT_TIMEOUT_MIN 5
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#define NFSROOT_TIMEOUT_MAX 30
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#define NFSROOT_RETRY_MAX 5
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static int __init mount_nfs_root(void)
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{
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char *root_dev, *root_data;
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unsigned int timeout;
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int try, err;
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err = nfs_root_data(&root_dev, &root_data);
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if (err != 0)
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return 0;
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/*
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* The server or network may not be ready, so try several
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* times. Stop after a few tries in case the client wants
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* to fall back to other boot methods.
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*/
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timeout = NFSROOT_TIMEOUT_MIN;
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for (try = 1; ; try++) {
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err = do_mount_root(root_dev, "nfs",
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root_mountflags, root_data);
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if (err == 0)
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return 1;
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if (try > NFSROOT_RETRY_MAX)
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break;
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/* Wait, in case the server refused us immediately */
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ssleep(timeout);
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timeout <<= 1;
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if (timeout > NFSROOT_TIMEOUT_MAX)
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timeout = NFSROOT_TIMEOUT_MAX;
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}
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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 (ROOT_DEV == Root_NFS) {
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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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#ifdef CONFIG_BLOCK
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create_dev("/dev/root", ROOT_DEV);
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mount_block_root("/dev/root", root_mountflags);
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#endif
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}
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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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|
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if (root_delay) {
|
|
printk(KERN_INFO "Waiting %d sec before mounting root device...\n",
|
|
root_delay);
|
|
ssleep(root_delay);
|
|
}
|
|
|
|
/*
|
|
* wait for the known devices to complete their probing
|
|
*
|
|
* Note: this is a potential source of long boot delays.
|
|
* For example, it is not atypical to wait 5 seconds here
|
|
* for the touchpad of a laptop to initialize.
|
|
*/
|
|
wait_for_device_probe();
|
|
|
|
md_run_setup();
|
|
|
|
if (saved_root_name[0]) {
|
|
root_device_name = saved_root_name;
|
|
if (!strncmp(root_device_name, "mtd", 3) ||
|
|
!strncmp(root_device_name, "ubi", 3)) {
|
|
mount_block_root(root_device_name, root_mountflags);
|
|
goto out;
|
|
}
|
|
ROOT_DEV = name_to_dev_t(root_device_name);
|
|
if (strncmp(root_device_name, "/dev/", 5) == 0)
|
|
root_device_name += 5;
|
|
}
|
|
|
|
if (initrd_load())
|
|
goto out;
|
|
|
|
/* wait for any asynchronous scanning to complete */
|
|
if ((ROOT_DEV == 0) && root_wait) {
|
|
printk(KERN_INFO "Waiting for root device %s...\n",
|
|
saved_root_name);
|
|
while (driver_probe_done() != 0 ||
|
|
(ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
|
|
msleep(100);
|
|
async_synchronize_full();
|
|
}
|
|
|
|
is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
|
|
|
|
if (is_floppy && rd_doload && rd_load_disk(0))
|
|
ROOT_DEV = Root_RAM0;
|
|
|
|
mount_root();
|
|
out:
|
|
devtmpfs_mount("dev");
|
|
sys_mount(".", "/", NULL, MS_MOVE, NULL);
|
|
sys_chroot(".");
|
|
}
|
|
|
|
static bool is_tmpfs;
|
|
static struct dentry *rootfs_mount(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name, void *data)
|
|
{
|
|
static unsigned long once;
|
|
void *fill = ramfs_fill_super;
|
|
|
|
if (test_and_set_bit(0, &once))
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
|
|
fill = shmem_fill_super;
|
|
|
|
return mount_nodev(fs_type, flags, data, fill);
|
|
}
|
|
|
|
static struct file_system_type rootfs_fs_type = {
|
|
.name = "rootfs",
|
|
.mount = rootfs_mount,
|
|
.kill_sb = kill_litter_super,
|
|
};
|
|
|
|
int __init init_rootfs(void)
|
|
{
|
|
int err = register_filesystem(&rootfs_fs_type);
|
|
|
|
if (err)
|
|
return err;
|
|
|
|
if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
|
|
(!root_fs_names || strstr(root_fs_names, "tmpfs"))) {
|
|
err = shmem_init();
|
|
is_tmpfs = true;
|
|
} else {
|
|
err = init_ramfs_fs();
|
|
}
|
|
|
|
if (err)
|
|
unregister_filesystem(&rootfs_fs_type);
|
|
|
|
return err;
|
|
}
|