Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/md/dm-init.c b/drivers/md/dm-init.c
new file mode 100644
index 0000000..b869316
--- /dev/null
+++ b/drivers/md/dm-init.c
@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * dm-init.c
+ * Copyright (C) 2017 The Chromium OS Authors <chromium-os-dev@chromium.org>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/ctype.h>
+#include <linux/device.h>
+#include <linux/device-mapper.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/moduleparam.h>
+
+#define DM_MSG_PREFIX "init"
+#define DM_MAX_DEVICES 256
+#define DM_MAX_TARGETS 256
+#define DM_MAX_STR_SIZE 4096
+
+static char *create;
+
+/*
+ * Format: dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]
+ * Table format: <start_sector> <num_sectors> <target_type> <target_args>
+ *
+ * See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." format
+ * details.
+ */
+
+struct dm_device {
+ struct dm_ioctl dmi;
+ struct dm_target_spec *table[DM_MAX_TARGETS];
+ char *target_args_array[DM_MAX_TARGETS];
+ struct list_head list;
+};
+
+const char * const dm_allowed_targets[] __initconst = {
+ "crypt",
+ "delay",
+ "linear",
+ "snapshot-origin",
+ "striped",
+ "verity",
+};
+
+static int __init dm_verify_target_type(const char *target)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(dm_allowed_targets); i++) {
+ if (!strcmp(dm_allowed_targets[i], target))
+ return 0;
+ }
+ return -EINVAL;
+}
+
+static void __init dm_setup_cleanup(struct list_head *devices)
+{
+ struct dm_device *dev, *tmp;
+ unsigned int i;
+
+ list_for_each_entry_safe(dev, tmp, devices, list) {
+ list_del(&dev->list);
+ for (i = 0; i < dev->dmi.target_count; i++) {
+ kfree(dev->table[i]);
+ kfree(dev->target_args_array[i]);
+ }
+ kfree(dev);
+ }
+}
+
+/**
+ * str_field_delimit - delimit a string based on a separator char.
+ * @str: the pointer to the string to delimit.
+ * @separator: char that delimits the field
+ *
+ * Find a @separator and replace it by '\0'.
+ * Remove leading and trailing spaces.
+ * Return the remainder string after the @separator.
+ */
+static char __init *str_field_delimit(char **str, char separator)
+{
+ char *s;
+
+ /* TODO: add support for escaped characters */
+ *str = skip_spaces(*str);
+ s = strchr(*str, separator);
+ /* Delimit the field and remove trailing spaces */
+ if (s)
+ *s = '\0';
+ *str = strim(*str);
+ return s ? ++s : NULL;
+}
+
+/**
+ * dm_parse_table_entry - parse a table entry
+ * @dev: device to store the parsed information.
+ * @str: the pointer to a string with the format:
+ * <start_sector> <num_sectors> <target_type> <target_args>[, ...]
+ *
+ * Return the remainder string after the table entry, i.e, after the comma which
+ * delimits the entry or NULL if reached the end of the string.
+ */
+static char __init *dm_parse_table_entry(struct dm_device *dev, char *str)
+{
+ const unsigned int n = dev->dmi.target_count - 1;
+ struct dm_target_spec *sp;
+ unsigned int i;
+ /* fields: */
+ char *field[4];
+ char *next;
+
+ field[0] = str;
+ /* Delimit first 3 fields that are separated by space */
+ for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
+ field[i + 1] = str_field_delimit(&field[i], ' ');
+ if (!field[i + 1])
+ return ERR_PTR(-EINVAL);
+ }
+ /* Delimit last field that can be terminated by comma */
+ next = str_field_delimit(&field[i], ',');
+
+ sp = kzalloc(sizeof(*sp), GFP_KERNEL);
+ if (!sp)
+ return ERR_PTR(-ENOMEM);
+ dev->table[n] = sp;
+
+ /* start_sector */
+ if (kstrtoull(field[0], 0, &sp->sector_start))
+ return ERR_PTR(-EINVAL);
+ /* num_sector */
+ if (kstrtoull(field[1], 0, &sp->length))
+ return ERR_PTR(-EINVAL);
+ /* target_type */
+ strscpy(sp->target_type, field[2], sizeof(sp->target_type));
+ if (dm_verify_target_type(sp->target_type)) {
+ DMERR("invalid type \"%s\"", sp->target_type);
+ return ERR_PTR(-EINVAL);
+ }
+ /* target_args */
+ dev->target_args_array[n] = kstrndup(field[3], DM_MAX_STR_SIZE,
+ GFP_KERNEL);
+ if (!dev->target_args_array[n])
+ return ERR_PTR(-ENOMEM);
+
+ return next;
+}
+
+/**
+ * dm_parse_table - parse "dm-mod.create=" table field
+ * @dev: device to store the parsed information.
+ * @str: the pointer to a string with the format:
+ * <table>[,<table>+]
+ */
+static int __init dm_parse_table(struct dm_device *dev, char *str)
+{
+ char *table_entry = str;
+
+ while (table_entry) {
+ DMDEBUG("parsing table \"%s\"", str);
+ if (++dev->dmi.target_count > DM_MAX_TARGETS) {
+ DMERR("too many targets %u > %d",
+ dev->dmi.target_count, DM_MAX_TARGETS);
+ return -EINVAL;
+ }
+ table_entry = dm_parse_table_entry(dev, table_entry);
+ if (IS_ERR(table_entry)) {
+ DMERR("couldn't parse table");
+ return PTR_ERR(table_entry);
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * dm_parse_device_entry - parse a device entry
+ * @dev: device to store the parsed information.
+ * @str: the pointer to a string with the format:
+ * name,uuid,minor,flags,table[; ...]
+ *
+ * Return the remainder string after the table entry, i.e, after the semi-colon
+ * which delimits the entry or NULL if reached the end of the string.
+ */
+static char __init *dm_parse_device_entry(struct dm_device *dev, char *str)
+{
+ /* There are 5 fields: name,uuid,minor,flags,table; */
+ char *field[5];
+ unsigned int i;
+ char *next;
+
+ field[0] = str;
+ /* Delimit first 4 fields that are separated by comma */
+ for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
+ field[i+1] = str_field_delimit(&field[i], ',');
+ if (!field[i+1])
+ return ERR_PTR(-EINVAL);
+ }
+ /* Delimit last field that can be delimited by semi-colon */
+ next = str_field_delimit(&field[i], ';');
+
+ /* name */
+ strscpy(dev->dmi.name, field[0], sizeof(dev->dmi.name));
+ /* uuid */
+ strscpy(dev->dmi.uuid, field[1], sizeof(dev->dmi.uuid));
+ /* minor */
+ if (strlen(field[2])) {
+ if (kstrtoull(field[2], 0, &dev->dmi.dev))
+ return ERR_PTR(-EINVAL);
+ dev->dmi.flags |= DM_PERSISTENT_DEV_FLAG;
+ }
+ /* flags */
+ if (!strcmp(field[3], "ro"))
+ dev->dmi.flags |= DM_READONLY_FLAG;
+ else if (strcmp(field[3], "rw"))
+ return ERR_PTR(-EINVAL);
+ /* table */
+ if (dm_parse_table(dev, field[4]))
+ return ERR_PTR(-EINVAL);
+
+ return next;
+}
+
+/**
+ * dm_parse_devices - parse "dm-mod.create=" argument
+ * @devices: list of struct dm_device to store the parsed information.
+ * @str: the pointer to a string with the format:
+ * <device>[;<device>+]
+ */
+static int __init dm_parse_devices(struct list_head *devices, char *str)
+{
+ unsigned long ndev = 0;
+ struct dm_device *dev;
+ char *device = str;
+
+ DMDEBUG("parsing \"%s\"", str);
+ while (device) {
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+ list_add_tail(&dev->list, devices);
+
+ if (++ndev > DM_MAX_DEVICES) {
+ DMERR("too many devices %lu > %d",
+ ndev, DM_MAX_DEVICES);
+ return -EINVAL;
+ }
+
+ device = dm_parse_device_entry(dev, device);
+ if (IS_ERR(device)) {
+ DMERR("couldn't parse device");
+ return PTR_ERR(device);
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * dm_init_init - parse "dm-mod.create=" argument and configure drivers
+ */
+static int __init dm_init_init(void)
+{
+ struct dm_device *dev;
+ LIST_HEAD(devices);
+ char *str;
+ int r;
+
+ if (!create)
+ return 0;
+
+ if (strlen(create) >= DM_MAX_STR_SIZE) {
+ DMERR("Argument is too big. Limit is %d", DM_MAX_STR_SIZE);
+ return -EINVAL;
+ }
+ str = kstrndup(create, DM_MAX_STR_SIZE, GFP_KERNEL);
+ if (!str)
+ return -ENOMEM;
+
+ r = dm_parse_devices(&devices, str);
+ if (r)
+ goto out;
+
+ DMINFO("waiting for all devices to be available before creating mapped devices");
+ wait_for_device_probe();
+
+ list_for_each_entry(dev, &devices, list) {
+ if (dm_early_create(&dev->dmi, dev->table,
+ dev->target_args_array))
+ break;
+ }
+out:
+ kfree(str);
+ dm_setup_cleanup(&devices);
+ return r;
+}
+
+late_initcall(dm_init_init);
+
+module_param(create, charp, 0);
+MODULE_PARM_DESC(create, "Create a mapped device in early boot");