md: move the early init autodetect code to drivers/md/

Just like the NFS and CIFS root code this better lives with the
driver it is tightly integrated with.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 315 insertions, 0 deletions

diff --git a/drivers/md/md-autodetect.c b/drivers/md/md-autodetect.c
new file mode 100644
index 000000000000..fe806f7b9759
--- /dev/null
+++ b/drivers/md/md-autodetect.c
@@ -0,0 +1,315 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/syscalls.h>
+#include <linux/mount.h>
+#include <linux/major.h>
+#include <linux/delay.h>
+#include <linux/raid/detect.h>
+#include <linux/raid/md_u.h>
+#include <linux/raid/md_p.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 {
+	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;
+		}
+		/* FALL THROUGH */
+	case 1: /* the first device is numeric */
+		str = str1;
+		/* FALL THROUGH */
+	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 inline int create_dev(char *name, dev_t dev)
+{
+	ksys_unlink(name);
+	return ksys_mknod(name, S_IFBLK|0600, new_encode_dev(dev));
+}
+
+static void __init md_setup_drive(void)
+{
+	int minor, i, ent, partitioned;
+	dev_t dev;
+	dev_t devices[MD_SB_DISKS+1];
+
+	for (ent = 0; ent < md_setup_ents ; ent++) {
+		int fd;
+		int err = 0;
+		char *devname;
+		mdu_disk_info_t dinfo;
+		char name[16];
+
+		minor = md_setup_args[ent].minor;
+		partitioned = md_setup_args[ent].partitioned;
+		devname = md_setup_args[ent].device_names;
+
+		sprintf(name, "/dev/md%s%d", partitioned?"_d":"", minor);
+		if (partitioned)
+			dev = MKDEV(mdp_major, minor << MdpMinorShift);
+		else
+			dev = MKDEV(MD_MAJOR, minor);
+		create_dev(name, dev);
+		for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
+			struct kstat stat;
+			char *p;
+			char comp_name[64];
+
+			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 (vfs_stat(comp_name, &stat) == 0 &&
+			    S_ISBLK(stat.mode))
+				dev = new_decode_dev(stat.rdev);
+			if (!dev) {
+				printk(KERN_WARNING "md: Unknown device name: %s\n", devname);
+				break;
+			}
+
+			devices[i] = dev;
+
+			devname = p;
+		}
+		devices[i] = 0;
+
+		if (!i)
+			continue;
+
+		printk(KERN_INFO "md: Loading md%s%d: %s\n",
+			partitioned ? "_d" : "", minor,
+			md_setup_args[ent].device_names);
+
+		fd = ksys_open(name, 0, 0);
+		if (fd < 0) {
+			printk(KERN_ERR "md: open failed - cannot start "
+					"array %s\n", name);
+			continue;
+		}
+		if (ksys_ioctl(fd, SET_ARRAY_INFO, 0) == -EBUSY) {
+			printk(KERN_WARNING
+			       "md: Ignoring md=%d, already autodetected. (Use raid=noautodetect)\n",
+			       minor);
+			ksys_close(fd);
+			continue;
+		}
+
+		if (md_setup_args[ent].level != LEVEL_NONE) {
+			/* non-persistent */
+			mdu_array_info_t ainfo;
+			ainfo.level = md_setup_args[ent].level;
+			ainfo.size = 0;
+			ainfo.nr_disks =0;
+			ainfo.raid_disks =0;
+			while (devices[ainfo.raid_disks])
+				ainfo.raid_disks++;
+			ainfo.md_minor =minor;
+			ainfo.not_persistent = 1;
+
+			ainfo.state = (1 << MD_SB_CLEAN);
+			ainfo.layout = 0;
+			ainfo.chunk_size = md_setup_args[ent].chunk;
+			err = ksys_ioctl(fd, SET_ARRAY_INFO, (long)&ainfo);
+			for (i = 0; !err && i <= MD_SB_DISKS; i++) {
+				dev = devices[i];
+				if (!dev)
+					break;
+				dinfo.number = i;
+				dinfo.raid_disk = i;
+				dinfo.state = (1<<MD_DISK_ACTIVE)|(1<<MD_DISK_SYNC);
+				dinfo.major = MAJOR(dev);
+				dinfo.minor = MINOR(dev);
+				err = ksys_ioctl(fd, ADD_NEW_DISK,
+						 (long)&dinfo);
+			}
+		} else {
+			/* persistent */
+			for (i = 0; i <= MD_SB_DISKS; i++) {
+				dev = devices[i];
+				if (!dev)
+					break;
+				dinfo.major = MAJOR(dev);
+				dinfo.minor = MINOR(dev);
+				ksys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo);
+			}
+		}
+		if (!err)
+			err = ksys_ioctl(fd, RUN_ARRAY, 0);
+		if (err)
+			printk(KERN_WARNING "md: starting md%d failed\n", minor);
+		else {
+			/* reread the partition table.
+			 * I (neilb) and not sure why this is needed, but I cannot
+			 * boot a kernel with devfs compiled in from partitioned md
+			 * array without it
+			 */
+			ksys_close(fd);
+			fd = ksys_open(name, 0, 0);
+			ksys_ioctl(fd, BLKRRPART, 0);
+		}
+		ksys_close(fd);
+	}
+}
+
+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)
+{
+	int fd;
+
+	/*
+	 * 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();
+
+	fd = ksys_open("/dev/md0", 0, 0);
+	if (fd >= 0) {
+		ksys_ioctl(fd, RAID_AUTORUN, raid_autopart);
+		ksys_close(fd);
+	}
+}
+
+void __init md_run_setup(void)
+{
+	create_dev("/dev/md0", MKDEV(MD_MAJOR, 0));
+
+	if (raid_noautodetect)
+		printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n");
+	else
+		autodetect_raid();
+	md_setup_drive();
+}