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-rw-r--r--drivers/md/md-autodetect.c282
1 files changed, 282 insertions, 0 deletions
diff --git a/drivers/md/md-autodetect.c b/drivers/md/md-autodetect.c
new file mode 100644
index 000000000..91836e6de
--- /dev/null
+++ b/drivers/md/md-autodetect.c
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/mount.h>
+#include <linux/major.h>
+#include <linux/delay.h>
+#include <linux/init_syscalls.h>
+#include <linux/raid/detect.h>
+#include <linux/raid/md_u.h>
+#include <linux/raid/md_p.h>
+#include "md.h"
+
+/*
+ * When md (and any require personalities) are compiled into the kernel
+ * (not a module), arrays can be assembles are boot time using with AUTODETECT
+ * where specially marked partitions are registered with md_autodetect_dev(),
+ * and with MD_BOOT where devices to be collected are given on the boot line
+ * with md=.....
+ * The code for that is here.
+ */
+
+#ifdef CONFIG_MD_AUTODETECT
+static int __initdata raid_noautodetect;
+#else
+static int __initdata raid_noautodetect=1;
+#endif
+static int __initdata raid_autopart;
+
+static struct md_setup_args {
+ int minor;
+ int partitioned;
+ int level;
+ int chunk;
+ char *device_names;
+} md_setup_args[256] __initdata;
+
+static int md_setup_ents __initdata;
+
+/*
+ * Parse the command-line parameters given our kernel, but do not
+ * actually try to invoke the MD device now; that is handled by
+ * md_setup_drive after the low-level disk drivers have initialised.
+ *
+ * 27/11/1999: Fixed to work correctly with the 2.3 kernel (which
+ * assigns the task of parsing integer arguments to the
+ * invoked program now). Added ability to initialise all
+ * the MD devices (by specifying multiple "md=" lines)
+ * instead of just one. -- KTK
+ * 18May2000: Added support for persistent-superblock arrays:
+ * md=n,0,factor,fault,device-list uses RAID0 for device n
+ * md=n,-1,factor,fault,device-list uses LINEAR for device n
+ * md=n,device-list reads a RAID superblock from the devices
+ * elements in device-list are read by name_to_kdev_t so can be
+ * a hex number or something like /dev/hda1 /dev/sdb
+ * 2001-06-03: Dave Cinege <dcinege@psychosis.com>
+ * Shifted name_to_kdev_t() and related operations to md_set_drive()
+ * for later execution. Rewrote section to make devfs compatible.
+ */
+static int __init md_setup(char *str)
+{
+ int minor, level, factor, fault, partitioned = 0;
+ char *pername = "";
+ char *str1;
+ int ent;
+
+ if (*str == 'd') {
+ partitioned = 1;
+ str++;
+ }
+ if (get_option(&str, &minor) != 2) { /* MD Number */
+ printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
+ return 0;
+ }
+ str1 = str;
+ for (ent=0 ; ent< md_setup_ents ; ent++)
+ if (md_setup_args[ent].minor == minor &&
+ md_setup_args[ent].partitioned == partitioned) {
+ printk(KERN_WARNING "md: md=%s%d, Specified more than once. "
+ "Replacing previous definition.\n", partitioned?"d":"", minor);
+ break;
+ }
+ if (ent >= ARRAY_SIZE(md_setup_args)) {
+ printk(KERN_WARNING "md: md=%s%d - too many md initialisations\n", partitioned?"d":"", minor);
+ return 0;
+ }
+ if (ent >= md_setup_ents)
+ md_setup_ents++;
+ switch (get_option(&str, &level)) { /* RAID level */
+ case 2: /* could be 0 or -1.. */
+ if (level == 0 || level == LEVEL_LINEAR) {
+ if (get_option(&str, &factor) != 2 || /* Chunk Size */
+ get_option(&str, &fault) != 2) {
+ printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
+ return 0;
+ }
+ md_setup_args[ent].level = level;
+ md_setup_args[ent].chunk = 1 << (factor+12);
+ if (level == LEVEL_LINEAR)
+ pername = "linear";
+ else
+ pername = "raid0";
+ break;
+ }
+ fallthrough;
+ case 1: /* the first device is numeric */
+ str = str1;
+ fallthrough;
+ case 0:
+ md_setup_args[ent].level = LEVEL_NONE;
+ pername="super-block";
+ }
+
+ printk(KERN_INFO "md: Will configure md%d (%s) from %s, below.\n",
+ minor, pername, str);
+ md_setup_args[ent].device_names = str;
+ md_setup_args[ent].partitioned = partitioned;
+ md_setup_args[ent].minor = minor;
+
+ return 1;
+}
+
+static void __init md_setup_drive(struct md_setup_args *args)
+{
+ char *devname = args->device_names;
+ dev_t devices[MD_SB_DISKS + 1], mdev;
+ struct mdu_array_info_s ainfo = { };
+ struct mddev *mddev;
+ int err = 0, i;
+ char name[16];
+
+ if (args->partitioned) {
+ mdev = MKDEV(mdp_major, args->minor << MdpMinorShift);
+ sprintf(name, "md_d%d", args->minor);
+ } else {
+ mdev = MKDEV(MD_MAJOR, args->minor);
+ sprintf(name, "md%d", args->minor);
+ }
+
+ for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
+ struct kstat stat;
+ char *p;
+ char comp_name[64];
+ dev_t dev;
+
+ p = strchr(devname, ',');
+ if (p)
+ *p++ = 0;
+
+ dev = name_to_dev_t(devname);
+ if (strncmp(devname, "/dev/", 5) == 0)
+ devname += 5;
+ snprintf(comp_name, 63, "/dev/%s", devname);
+ if (init_stat(comp_name, &stat, 0) == 0 && S_ISBLK(stat.mode))
+ dev = new_decode_dev(stat.rdev);
+ if (!dev) {
+ pr_warn("md: Unknown device name: %s\n", devname);
+ break;
+ }
+
+ devices[i] = dev;
+ devname = p;
+ }
+ devices[i] = 0;
+
+ if (!i)
+ return;
+
+ pr_info("md: Loading %s: %s\n", name, args->device_names);
+
+ mddev = md_alloc(mdev, name);
+ if (IS_ERR(mddev)) {
+ pr_err("md: md_alloc failed - cannot start array %s\n", name);
+ return;
+ }
+
+ err = mddev_lock(mddev);
+ if (err) {
+ pr_err("md: failed to lock array %s\n", name);
+ goto out_mddev_put;
+ }
+
+ if (!list_empty(&mddev->disks) || mddev->raid_disks) {
+ pr_warn("md: Ignoring %s, already autodetected. (Use raid=noautodetect)\n",
+ name);
+ goto out_unlock;
+ }
+
+ if (args->level != LEVEL_NONE) {
+ /* non-persistent */
+ ainfo.level = args->level;
+ ainfo.md_minor = args->minor;
+ ainfo.not_persistent = 1;
+ ainfo.state = (1 << MD_SB_CLEAN);
+ ainfo.chunk_size = args->chunk;
+ while (devices[ainfo.raid_disks])
+ ainfo.raid_disks++;
+ }
+
+ err = md_set_array_info(mddev, &ainfo);
+
+ for (i = 0; i <= MD_SB_DISKS && devices[i]; i++) {
+ struct mdu_disk_info_s dinfo = {
+ .major = MAJOR(devices[i]),
+ .minor = MINOR(devices[i]),
+ };
+
+ if (args->level != LEVEL_NONE) {
+ dinfo.number = i;
+ dinfo.raid_disk = i;
+ dinfo.state =
+ (1 << MD_DISK_ACTIVE) | (1 << MD_DISK_SYNC);
+ }
+
+ md_add_new_disk(mddev, &dinfo);
+ }
+
+ if (!err)
+ err = do_md_run(mddev);
+ if (err)
+ pr_warn("md: starting %s failed\n", name);
+out_unlock:
+ mddev_unlock(mddev);
+out_mddev_put:
+ mddev_put(mddev);
+}
+
+static int __init raid_setup(char *str)
+{
+ int len, pos;
+
+ len = strlen(str) + 1;
+ pos = 0;
+
+ while (pos < len) {
+ char *comma = strchr(str+pos, ',');
+ int wlen;
+ if (comma)
+ wlen = (comma-str)-pos;
+ else wlen = (len-1)-pos;
+
+ if (!strncmp(str, "noautodetect", wlen))
+ raid_noautodetect = 1;
+ if (!strncmp(str, "autodetect", wlen))
+ raid_noautodetect = 0;
+ if (strncmp(str, "partitionable", wlen)==0)
+ raid_autopart = 1;
+ if (strncmp(str, "part", wlen)==0)
+ raid_autopart = 1;
+ pos += wlen+1;
+ }
+ return 1;
+}
+
+__setup("raid=", raid_setup);
+__setup("md=", md_setup);
+
+static void __init autodetect_raid(void)
+{
+ /*
+ * Since we don't want to detect and use half a raid array, we need to
+ * wait for the known devices to complete their probing
+ */
+ printk(KERN_INFO "md: Waiting for all devices to be available before autodetect\n");
+ printk(KERN_INFO "md: If you don't use raid, use raid=noautodetect\n");
+
+ wait_for_device_probe();
+ md_autostart_arrays(raid_autopart);
+}
+
+void __init md_run_setup(void)
+{
+ int ent;
+
+ if (raid_noautodetect)
+ printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n");
+ else
+ autodetect_raid();
+
+ for (ent = 0; ent < md_setup_ents; ent++)
+ md_setup_drive(&md_setup_args[ent]);
+}
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