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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /init/do_mounts.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'init/do_mounts.c')
-rw-r--r--init/do_mounts.c674
1 files changed, 674 insertions, 0 deletions
diff --git a/init/do_mounts.c b/init/do_mounts.c
new file mode 100644
index 000000000..2d705b9c8
--- /dev/null
+++ b/init/do_mounts.c
@@ -0,0 +1,674 @@
+// 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)
+{
+ strscpy(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;
+
+ strscpy(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)) {
+ if (!saved_root_name[0] && !root_fs_names)
+ is_tmpfs = true;
+ else if (root_fs_names && !!strstr(root_fs_names, "tmpfs"))
+ is_tmpfs = true;
+ }
+}