do_mounts_md.c

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/*
 * Many of the syscalls used in this file expect some of the arguments
 * to be __user pointers not __kernel pointers.  To limit the sparse
 * noise, turn off sparse checking for this file.
 */
#ifdef __CHECKER__
#undef __CHECKER__
#warning "Sparse checking disabled for this file"
#endif

#include <linux/delay.h>
#include <linux/raid/md_u.h>
#include <linux/raid/md_p.h>

#include "do_mounts.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 <[email protected]>
 *      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 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++) {
            char *p;
            char comp_name[64];
            u32 rdev;

            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);
            rdev = bstat(comp_name);
            if (rdev)
                dev = new_decode_dev(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 = sys_open(name, 0, 0);
        if (fd < 0) {
            printk(KERN_ERR "md: open failed - cannot start "
                    "array %s\n", name);
            continue;
        }
        if (sys_ioctl(fd, SET_ARRAY_INFO, 0) == -EBUSY) {
            printk(KERN_WARNING
                   "md: Ignoring md=%d, already autodetected. (Use raid=noautodetect)\n",
                   minor);
            sys_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 = sys_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 = sys_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);
                sys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo);
            }
        }
        if (!err)
            err = sys_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
             */
            sys_close(fd);
            fd = sys_open(name, 0, 0);
            sys_ioctl(fd, BLKRRPART, 0);
        }
        sys_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 = sys_open("/dev/md0", 0, 0);
    if (fd >= 0) {
        sys_ioctl(fd, RAID_AUTORUN, raid_autopart);
        sys_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();
}