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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-21 19:53:59 +08:00
linux-next/init/do_mounts.c
Christoph Hellwig 322cbb50de block: remove genhd.h
There is no good reason to keep genhd.h separate from the main blkdev.h
header that includes it.  So fold the contents of genhd.h into blkdev.h
and remove genhd.h entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220124093913.742411-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02 07:49:59 -07:00

672 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include <linux/fd.h>
#include <linux/tty.h>
#include <linux/suspend.h>
#include <linux/root_dev.h>
#include <linux/security.h>
#include <linux/delay.h>
#include <linux/mount.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/initrd.h>
#include <linux/async.h>
#include <linux/fs_struct.h>
#include <linux/slab.h>
#include <linux/ramfs.h>
#include <linux/shmem_fs.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/nfs_mount.h>
#include <linux/raid/detect.h>
#include <uapi/linux/mount.h>
#include "do_mounts.h"
int root_mountflags = MS_RDONLY | MS_SILENT;
static char * __initdata root_device_name;
static char __initdata saved_root_name[64];
static int root_wait;
dev_t ROOT_DEV;
static int __init load_ramdisk(char *str)
{
pr_warn("ignoring the deprecated load_ramdisk= option\n");
return 1;
}
__setup("load_ramdisk=", load_ramdisk);
static int __init readonly(char *str)
{
if (*str)
return 0;
root_mountflags |= MS_RDONLY;
return 1;
}
static int __init readwrite(char *str)
{
if (*str)
return 0;
root_mountflags &= ~MS_RDONLY;
return 1;
}
__setup("ro", readonly);
__setup("rw", readwrite);
#ifdef CONFIG_BLOCK
struct uuidcmp {
const char *uuid;
int len;
};
/**
* match_dev_by_uuid - callback for finding a partition using its uuid
* @dev: device passed in by the caller
* @data: opaque pointer to the desired struct uuidcmp to match
*
* Returns 1 if the device matches, and 0 otherwise.
*/
static int match_dev_by_uuid(struct device *dev, const void *data)
{
struct block_device *bdev = dev_to_bdev(dev);
const struct uuidcmp *cmp = data;
if (!bdev->bd_meta_info ||
strncasecmp(cmp->uuid, bdev->bd_meta_info->uuid, cmp->len))
return 0;
return 1;
}
/**
* devt_from_partuuid - looks up the dev_t of a partition by its UUID
* @uuid_str: char array containing ascii UUID
*
* The function will return the first partition which contains a matching
* UUID value in its partition_meta_info struct. This does not search
* by filesystem UUIDs.
*
* If @uuid_str is followed by a "/PARTNROFF=%d", then the number will be
* extracted and used as an offset from the partition identified by the UUID.
*
* Returns the matching dev_t on success or 0 on failure.
*/
static dev_t devt_from_partuuid(const char *uuid_str)
{
struct uuidcmp cmp;
struct device *dev = NULL;
dev_t devt = 0;
int offset = 0;
char *slash;
cmp.uuid = uuid_str;
slash = strchr(uuid_str, '/');
/* Check for optional partition number offset attributes. */
if (slash) {
char c = 0;
/* Explicitly fail on poor PARTUUID syntax. */
if (sscanf(slash + 1, "PARTNROFF=%d%c", &offset, &c) != 1)
goto clear_root_wait;
cmp.len = slash - uuid_str;
} else {
cmp.len = strlen(uuid_str);
}
if (!cmp.len)
goto clear_root_wait;
dev = class_find_device(&block_class, NULL, &cmp, &match_dev_by_uuid);
if (!dev)
return 0;
if (offset) {
/*
* Attempt to find the requested partition by adding an offset
* to the partition number found by UUID.
*/
devt = part_devt(dev_to_disk(dev),
dev_to_bdev(dev)->bd_partno + offset);
} else {
devt = dev->devt;
}
put_device(dev);
return devt;
clear_root_wait:
pr_err("VFS: PARTUUID= is invalid.\n"
"Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
if (root_wait)
pr_err("Disabling rootwait; root= is invalid.\n");
root_wait = 0;
return 0;
}
/**
* match_dev_by_label - callback for finding a partition using its label
* @dev: device passed in by the caller
* @data: opaque pointer to the label to match
*
* Returns 1 if the device matches, and 0 otherwise.
*/
static int match_dev_by_label(struct device *dev, const void *data)
{
struct block_device *bdev = dev_to_bdev(dev);
const char *label = data;
if (!bdev->bd_meta_info || strcmp(label, bdev->bd_meta_info->volname))
return 0;
return 1;
}
static dev_t devt_from_partlabel(const char *label)
{
struct device *dev;
dev_t devt = 0;
dev = class_find_device(&block_class, NULL, label, &match_dev_by_label);
if (dev) {
devt = dev->devt;
put_device(dev);
}
return devt;
}
static dev_t devt_from_devname(const char *name)
{
dev_t devt = 0;
int part;
char s[32];
char *p;
if (strlen(name) > 31)
return 0;
strcpy(s, name);
for (p = s; *p; p++) {
if (*p == '/')
*p = '!';
}
devt = blk_lookup_devt(s, 0);
if (devt)
return devt;
/*
* Try non-existent, but valid partition, which may only exist after
* opening the device, like partitioned md devices.
*/
while (p > s && isdigit(p[-1]))
p--;
if (p == s || !*p || *p == '0')
return 0;
/* try disk name without <part number> */
part = simple_strtoul(p, NULL, 10);
*p = '\0';
devt = blk_lookup_devt(s, part);
if (devt)
return devt;
/* try disk name without p<part number> */
if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
return 0;
p[-1] = '\0';
return blk_lookup_devt(s, part);
}
#endif /* CONFIG_BLOCK */
static dev_t devt_from_devnum(const char *name)
{
unsigned maj, min, offset;
dev_t devt = 0;
char *p, dummy;
if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3) {
devt = MKDEV(maj, min);
if (maj != MAJOR(devt) || min != MINOR(devt))
return 0;
} else {
devt = new_decode_dev(simple_strtoul(name, &p, 16));
if (*p)
return 0;
}
return devt;
}
/*
* Convert a name into device number. We accept the following variants:
*
* 1) <hex_major><hex_minor> device number in hexadecimal represents itself
* no leading 0x, for example b302.
* 2) /dev/nfs represents Root_NFS (0xff)
* 3) /dev/<disk_name> represents the device number of disk
* 4) /dev/<disk_name><decimal> represents the device number
* of partition - device number of disk plus the partition number
* 5) /dev/<disk_name>p<decimal> - same as the above, that form is
* used when disk name of partitioned disk ends on a digit.
* 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
* unique id of a partition if the partition table provides it.
* The UUID may be either an EFI/GPT UUID, or refer to an MSDOS
* partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero-
* filled hex representation of the 32-bit "NT disk signature", and PP
* is a zero-filled hex representation of the 1-based partition number.
* 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
* a partition with a known unique id.
* 8) <major>:<minor> major and minor number of the device separated by
* a colon.
* 9) PARTLABEL=<name> with name being the GPT partition label.
* MSDOS partitions do not support labels!
* 10) /dev/cifs represents Root_CIFS (0xfe)
*
* If name doesn't have fall into the categories above, we return (0,0).
* block_class is used to check if something is a disk name. If the disk
* name contains slashes, the device name has them replaced with
* bangs.
*/
dev_t name_to_dev_t(const char *name)
{
if (strcmp(name, "/dev/nfs") == 0)
return Root_NFS;
if (strcmp(name, "/dev/cifs") == 0)
return Root_CIFS;
if (strcmp(name, "/dev/ram") == 0)
return Root_RAM0;
#ifdef CONFIG_BLOCK
if (strncmp(name, "PARTUUID=", 9) == 0)
return devt_from_partuuid(name + 9);
if (strncmp(name, "PARTLABEL=", 10) == 0)
return devt_from_partlabel(name + 10);
if (strncmp(name, "/dev/", 5) == 0)
return devt_from_devname(name + 5);
#endif
return devt_from_devnum(name);
}
EXPORT_SYMBOL_GPL(name_to_dev_t);
static int __init root_dev_setup(char *line)
{
strlcpy(saved_root_name, line, sizeof(saved_root_name));
return 1;
}
__setup("root=", root_dev_setup);
static int __init rootwait_setup(char *str)
{
if (*str)
return 0;
root_wait = 1;
return 1;
}
__setup("rootwait", rootwait_setup);
static char * __initdata root_mount_data;
static int __init root_data_setup(char *str)
{
root_mount_data = str;
return 1;
}
static char * __initdata root_fs_names;
static int __init fs_names_setup(char *str)
{
root_fs_names = str;
return 1;
}
static unsigned int __initdata root_delay;
static int __init root_delay_setup(char *str)
{
root_delay = simple_strtoul(str, NULL, 0);
return 1;
}
__setup("rootflags=", root_data_setup);
__setup("rootfstype=", fs_names_setup);
__setup("rootdelay=", root_delay_setup);
/* This can return zero length strings. Caller should check */
static int __init split_fs_names(char *page, size_t size, char *names)
{
int count = 1;
char *p = page;
strlcpy(p, root_fs_names, size);
while (*p++) {
if (p[-1] == ',') {
p[-1] = '\0';
count++;
}
}
return count;
}
static int __init do_mount_root(const char *name, const char *fs,
const int flags, const void *data)
{
struct super_block *s;
struct page *p = NULL;
char *data_page = NULL;
int ret;
if (data) {
/* init_mount() requires a full page as fifth argument */
p = alloc_page(GFP_KERNEL);
if (!p)
return -ENOMEM;
data_page = page_address(p);
/* zero-pad. init_mount() will make sure it's terminated */
strncpy(data_page, data, PAGE_SIZE);
}
ret = init_mount(name, "/root", fs, flags, data_page);
if (ret)
goto out;
init_chdir("/root");
s = current->fs->pwd.dentry->d_sb;
ROOT_DEV = s->s_dev;
printk(KERN_INFO
"VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
s->s_type->name,
sb_rdonly(s) ? " readonly" : "",
MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
out:
if (p)
put_page(p);
return ret;
}
void __init mount_block_root(char *name, int flags)
{
struct page *page = alloc_page(GFP_KERNEL);
char *fs_names = page_address(page);
char *p;
char b[BDEVNAME_SIZE];
int num_fs, i;
scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)",
MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
if (root_fs_names)
num_fs = split_fs_names(fs_names, PAGE_SIZE, root_fs_names);
else
num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
retry:
for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) {
int err;
if (!*p)
continue;
err = do_mount_root(name, p, flags, root_mount_data);
switch (err) {
case 0:
goto out;
case -EACCES:
case -EINVAL:
continue;
}
/*
* Allow the user to distinguish between failed sys_open
* and bad superblock on root device.
* and give them a list of the available devices
*/
printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
root_device_name, b, err);
printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
printk_all_partitions();
panic("VFS: Unable to mount root fs on %s", b);
}
if (!(flags & SB_RDONLY)) {
flags |= SB_RDONLY;
goto retry;
}
printk("List of all partitions:\n");
printk_all_partitions();
printk("No filesystem could mount root, tried: ");
for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
printk(" %s", p);
printk("\n");
panic("VFS: Unable to mount root fs on %s", b);
out:
put_page(page);
}
#ifdef CONFIG_ROOT_NFS
#define NFSROOT_TIMEOUT_MIN 5
#define NFSROOT_TIMEOUT_MAX 30
#define NFSROOT_RETRY_MAX 5
static int __init mount_nfs_root(void)
{
char *root_dev, *root_data;
unsigned int timeout;
int try, err;
err = nfs_root_data(&root_dev, &root_data);
if (err != 0)
return 0;
/*
* The server or network may not be ready, so try several
* times. Stop after a few tries in case the client wants
* to fall back to other boot methods.
*/
timeout = NFSROOT_TIMEOUT_MIN;
for (try = 1; ; try++) {
err = do_mount_root(root_dev, "nfs",
root_mountflags, root_data);
if (err == 0)
return 1;
if (try > NFSROOT_RETRY_MAX)
break;
/* Wait, in case the server refused us immediately */
ssleep(timeout);
timeout <<= 1;
if (timeout > NFSROOT_TIMEOUT_MAX)
timeout = NFSROOT_TIMEOUT_MAX;
}
return 0;
}
#endif
#ifdef CONFIG_CIFS_ROOT
extern int cifs_root_data(char **dev, char **opts);
#define CIFSROOT_TIMEOUT_MIN 5
#define CIFSROOT_TIMEOUT_MAX 30
#define CIFSROOT_RETRY_MAX 5
static int __init mount_cifs_root(void)
{
char *root_dev, *root_data;
unsigned int timeout;
int try, err;
err = cifs_root_data(&root_dev, &root_data);
if (err != 0)
return 0;
timeout = CIFSROOT_TIMEOUT_MIN;
for (try = 1; ; try++) {
err = do_mount_root(root_dev, "cifs", root_mountflags,
root_data);
if (err == 0)
return 1;
if (try > CIFSROOT_RETRY_MAX)
break;
ssleep(timeout);
timeout <<= 1;
if (timeout > CIFSROOT_TIMEOUT_MAX)
timeout = CIFSROOT_TIMEOUT_MAX;
}
return 0;
}
#endif
static bool __init fs_is_nodev(char *fstype)
{
struct file_system_type *fs = get_fs_type(fstype);
bool ret = false;
if (fs) {
ret = !(fs->fs_flags & FS_REQUIRES_DEV);
put_filesystem(fs);
}
return ret;
}
static int __init mount_nodev_root(void)
{
char *fs_names, *fstype;
int err = -EINVAL;
int num_fs, i;
fs_names = (void *)__get_free_page(GFP_KERNEL);
if (!fs_names)
return -EINVAL;
num_fs = split_fs_names(fs_names, PAGE_SIZE, root_fs_names);
for (i = 0, fstype = fs_names; i < num_fs;
i++, fstype += strlen(fstype) + 1) {
if (!*fstype)
continue;
if (!fs_is_nodev(fstype))
continue;
err = do_mount_root(root_device_name, fstype, root_mountflags,
root_mount_data);
if (!err)
break;
}
free_page((unsigned long)fs_names);
return err;
}
void __init mount_root(void)
{
#ifdef CONFIG_ROOT_NFS
if (ROOT_DEV == Root_NFS) {
if (!mount_nfs_root())
printk(KERN_ERR "VFS: Unable to mount root fs via NFS.\n");
return;
}
#endif
#ifdef CONFIG_CIFS_ROOT
if (ROOT_DEV == Root_CIFS) {
if (!mount_cifs_root())
printk(KERN_ERR "VFS: Unable to mount root fs via SMB.\n");
return;
}
#endif
if (ROOT_DEV == 0 && root_device_name && root_fs_names) {
if (mount_nodev_root() == 0)
return;
}
#ifdef CONFIG_BLOCK
{
int err = create_dev("/dev/root", ROOT_DEV);
if (err < 0)
pr_emerg("Failed to create /dev/root: %d\n", err);
mount_block_root("/dev/root", root_mountflags);
}
#endif
}
/*
* Prepare the namespace - decide what/where to mount, load ramdisks, etc.
*/
void __init prepare_namespace(void)
{
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(5);
async_synchronize_full();
}
mount_root();
out:
devtmpfs_mount();
init_mount(".", "/", NULL, MS_MOVE, NULL);
init_chroot(".");
}
static bool is_tmpfs;
static int rootfs_init_fs_context(struct fs_context *fc)
{
if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
return shmem_init_fs_context(fc);
return ramfs_init_fs_context(fc);
}
struct file_system_type rootfs_fs_type = {
.name = "rootfs",
.init_fs_context = rootfs_init_fs_context,
.kill_sb = kill_litter_super,
};
void __init init_rootfs(void)
{
if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
(!root_fs_names || strstr(root_fs_names, "tmpfs")))
is_tmpfs = true;
}