| /* |
| * Many of the syscalls used in this file expect some of the arguments |
| * to be __user pointers not __kernel pointers. To limit the sparse |
| * noise, turn off sparse checking for this file. |
| */ |
| #ifdef __CHECKER__ |
| #undef __CHECKER__ |
| #warning "Sparse checking disabled for this file" |
| #endif |
| |
| #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/genhd.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 "do_mounts.h" |
| |
| int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */ |
| |
| 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) |
| { |
| rd_doload = simple_strtol(str,NULL,0) & 3; |
| 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) |
| { |
| const struct uuidcmp *cmp = data; |
| struct hd_struct *part = dev_to_part(dev); |
| |
| if (!part->info) |
| goto no_match; |
| |
| if (strncasecmp(cmp->uuid, part->info->uuid, cmp->len)) |
| goto no_match; |
| |
| return 1; |
| no_match: |
| return 0; |
| } |
| |
| |
| /** |
| * 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) |
| { |
| dev_t res = 0; |
| struct uuidcmp cmp; |
| struct device *dev = NULL; |
| struct gendisk *disk; |
| struct hd_struct *part; |
| int offset = 0; |
| bool clear_root_wait = false; |
| 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) { |
| clear_root_wait = true; |
| goto done; |
| } |
| cmp.len = slash - uuid_str; |
| } else { |
| cmp.len = strlen(uuid_str); |
| } |
| |
| if (!cmp.len) { |
| clear_root_wait = true; |
| goto done; |
| } |
| |
| dev = class_find_device(&block_class, NULL, &cmp, |
| &match_dev_by_uuid); |
| if (!dev) |
| goto done; |
| |
| res = dev->devt; |
| |
| /* Attempt to find the partition by offset. */ |
| if (!offset) |
| goto no_offset; |
| |
| res = 0; |
| disk = part_to_disk(dev_to_part(dev)); |
| part = disk_get_part(disk, dev_to_part(dev)->partno + offset); |
| if (part) { |
| res = part_devt(part); |
| put_device(part_to_dev(part)); |
| } |
| |
| no_offset: |
| put_device(dev); |
| done: |
| if (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 res; |
| } |
| #endif |
| |
| /* |
| * 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. |
| * |
| * 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) |
| { |
| char s[32]; |
| char *p; |
| dev_t res = 0; |
| int part; |
| |
| #ifdef CONFIG_BLOCK |
| if (strncmp(name, "PARTUUID=", 9) == 0) { |
| name += 9; |
| res = devt_from_partuuid(name); |
| if (!res) |
| goto fail; |
| goto done; |
| } |
| #endif |
| |
| if (strncmp(name, "/dev/", 5) != 0) { |
| unsigned maj, min, offset; |
| char dummy; |
| |
| if ((sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2) || |
| (sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3)) { |
| res = MKDEV(maj, min); |
| if (maj != MAJOR(res) || min != MINOR(res)) |
| goto fail; |
| } else { |
| res = new_decode_dev(simple_strtoul(name, &p, 16)); |
| if (*p) |
| goto fail; |
| } |
| goto done; |
| } |
| |
| name += 5; |
| res = Root_NFS; |
| if (strcmp(name, "nfs") == 0) |
| goto done; |
| res = Root_RAM0; |
| if (strcmp(name, "ram") == 0) |
| goto done; |
| |
| if (strlen(name) > 31) |
| goto fail; |
| strcpy(s, name); |
| for (p = s; *p; p++) |
| if (*p == '/') |
| *p = '!'; |
| res = blk_lookup_devt(s, 0); |
| if (res) |
| goto done; |
| |
| /* |
| * try non-existent, but valid partition, which may only exist |
| * after revalidating the disk, like partitioned md devices |
| */ |
| while (p > s && isdigit(p[-1])) |
| p--; |
| if (p == s || !*p || *p == '0') |
| goto fail; |
| |
| /* try disk name without <part number> */ |
| part = simple_strtoul(p, NULL, 10); |
| *p = '\0'; |
| res = blk_lookup_devt(s, part); |
| if (res) |
| goto done; |
| |
| /* try disk name without p<part number> */ |
| if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') |
| goto fail; |
| p[-1] = '\0'; |
| res = blk_lookup_devt(s, part); |
| if (res) |
| goto done; |
| |
| fail: |
| return 0; |
| done: |
| return res; |
| } |
| 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); |
| |
| static void __init get_fs_names(char *page) |
| { |
| char *s = page; |
| |
| if (root_fs_names) { |
| strcpy(page, root_fs_names); |
| while (*s++) { |
| if (s[-1] == ',') |
| s[-1] = '\0'; |
| } |
| } else { |
| int len = get_filesystem_list(page); |
| char *p, *next; |
| |
| page[len] = '\0'; |
| for (p = page-1; p; p = next) { |
| next = strchr(++p, '\n'); |
| if (*p++ != '\t') |
| continue; |
| while ((*s++ = *p++) != '\n') |
| ; |
| s[-1] = '\0'; |
| } |
| } |
| *s = '\0'; |
| } |
| |
| static int __init do_mount_root(char *name, char *fs, int flags, void *data) |
| { |
| struct super_block *s; |
| int err = sys_mount(name, "/root", fs, flags, data); |
| if (err) |
| return err; |
| |
| sys_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)); |
| return 0; |
| } |
| |
| void __init mount_block_root(char *name, int flags) |
| { |
| struct page *page = alloc_page(GFP_KERNEL); |
| char *fs_names = page_address(page); |
| char *p; |
| #ifdef CONFIG_BLOCK |
| char b[BDEVNAME_SIZE]; |
| #else |
| const char *b = name; |
| #endif |
| |
| get_fs_names(fs_names); |
| retry: |
| for (p = fs_names; *p; p += strlen(p)+1) { |
| int 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 |
| */ |
| #ifdef CONFIG_BLOCK |
| __bdevname(ROOT_DEV, b); |
| #endif |
| 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(); |
| #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT |
| printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify " |
| "explicit textual name for \"root=\" boot option.\n"); |
| #endif |
| 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 (p = fs_names; *p; p += strlen(p)+1) |
| printk(" %s", p); |
| printk("\n"); |
| #ifdef CONFIG_BLOCK |
| __bdevname(ROOT_DEV, b); |
| #endif |
| 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 |
| |
| #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD) |
| void __init change_floppy(char *fmt, ...) |
| { |
| struct termios termios; |
| char buf[80]; |
| char c; |
| int fd; |
| va_list args; |
| va_start(args, fmt); |
| vsprintf(buf, fmt, args); |
| va_end(args); |
| fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0); |
| if (fd >= 0) { |
| sys_ioctl(fd, FDEJECT, 0); |
| sys_close(fd); |
| } |
| printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf); |
| fd = sys_open("/dev/console", O_RDWR, 0); |
| if (fd >= 0) { |
| sys_ioctl(fd, TCGETS, (long)&termios); |
| termios.c_lflag &= ~ICANON; |
| sys_ioctl(fd, TCSETSF, (long)&termios); |
| sys_read(fd, &c, 1); |
| termios.c_lflag |= ICANON; |
| sys_ioctl(fd, TCSETSF, (long)&termios); |
| sys_close(fd); |
| } |
| } |
| #endif |
| |
| void __init mount_root(void) |
| { |
| #ifdef CONFIG_ROOT_NFS |
| if (ROOT_DEV == Root_NFS) { |
| if (mount_nfs_root()) |
| return; |
| |
| printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n"); |
| ROOT_DEV = Root_FD0; |
| } |
| #endif |
| #ifdef CONFIG_BLK_DEV_FD |
| if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) { |
| /* rd_doload is 2 for a dual initrd/ramload setup */ |
| if (rd_doload==2) { |
| if (rd_load_disk(1)) { |
| ROOT_DEV = Root_RAM1; |
| root_device_name = NULL; |
| } |
| } else |
| change_floppy("root floppy"); |
| } |
| #endif |
| #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) |
| { |
| int is_floppy; |
| |
| 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(); |
| dm_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(); |
| } |
| |
| 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; |
| } |