// 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;

                if (early_lookup_bdev(devname, &dev))
                        dev = 0;
                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_suspend_and_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_and_resume(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]);
}