v4.19.13 snapshot.
diff --git a/init/do_mounts.c b/init/do_mounts.c
new file mode 100644
index 0000000..e1c9afa
--- /dev/null
+++ b/init/do_mounts.c
@@ -0,0 +1,637 @@
+#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 = ksys_mount(name, "/root", fs, flags, data);
+ if (err)
+ return err;
+
+ ksys_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 = ksys_open("/dev/root", O_RDWR | O_NDELAY, 0);
+ if (fd >= 0) {
+ ksys_ioctl(fd, FDEJECT, 0);
+ ksys_close(fd);
+ }
+ printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
+ fd = ksys_open("/dev/console", O_RDWR, 0);
+ if (fd >= 0) {
+ ksys_ioctl(fd, TCGETS, (long)&termios);
+ termios.c_lflag &= ~ICANON;
+ ksys_ioctl(fd, TCSETSF, (long)&termios);
+ ksys_read(fd, &c, 1);
+ termios.c_lflag |= ICANON;
+ ksys_ioctl(fd, TCSETSF, (long)&termios);
+ ksys_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();
+
+ 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");
+ ksys_mount(".", "/", NULL, MS_MOVE, NULL);
+ ksys_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;
+}