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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [drivers/] [md/] [md.c] - Blame information for rev 1774

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/*
   md.c : Multiple Devices driver for Linux
          Copyright (C) 1998, 1999, 2000 Ingo Molnar
 
     completely rewritten, based on the MD driver code from Marc Zyngier
 
   Changes:
 
   - RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar
   - boot support for linear and striped mode by Harald Hoyer <HarryH@Royal.Net>
   - kerneld support by Boris Tobotras <boris@xtalk.msk.su>
   - kmod support by: Cyrus Durgin
   - RAID0 bugfixes: Mark Anthony Lisher <markal@iname.com>
   - Devfs support by Richard Gooch <rgooch@atnf.csiro.au>
 
   - lots of fixes and improvements to the RAID1/RAID5 and generic
     RAID code (such as request based resynchronization):
 
     Neil Brown <neilb@cse.unsw.edu.au>.
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.
 
   You should have received a copy of the GNU General Public License
   (for example /usr/src/linux/COPYING); if not, write to the Free
   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
 
#include <linux/module.h>
#include <linux/config.h>
#include <linux/raid/md.h>
#include <linux/sysctl.h>
#include <linux/raid/xor.h>
#include <linux/devfs_fs_kernel.h>
 
#include <linux/init.h>
 
#ifdef CONFIG_KMOD
#include <linux/kmod.h>
#endif
 
#define __KERNEL_SYSCALLS__
#include <linux/unistd.h>
 
#include <asm/unaligned.h>
 
#define MAJOR_NR MD_MAJOR
#define MD_DRIVER
 
#include <linux/blk.h>
 
#define DEBUG 0
#if DEBUG
# define dprintk(x...) printk(x)
#else
# define dprintk(x...) do { } while(0)
#endif
 
#ifndef MODULE
static void autostart_arrays (void);
#endif
 
static mdk_personality_t *pers[MAX_PERSONALITY];
 
/*
 * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
 * is 100 KB/sec, so the extra system load does not show up that much.
 * Increase it if you want to have more _guaranteed_ speed. Note that
 * the RAID driver will use the maximum available bandwith if the IO
 * subsystem is idle. There is also an 'absolute maximum' reconstruction
 * speed limit - in case reconstruction slows down your system despite
 * idle IO detection.
 *
 * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
 */
 
static int sysctl_speed_limit_min = 100;
static int sysctl_speed_limit_max = 100000;
 
static struct ctl_table_header *raid_table_header;
 
static ctl_table raid_table[] = {
        {DEV_RAID_SPEED_LIMIT_MIN, "speed_limit_min",
         &sysctl_speed_limit_min, sizeof(int), 0644, NULL, &proc_dointvec},
        {DEV_RAID_SPEED_LIMIT_MAX, "speed_limit_max",
         &sysctl_speed_limit_max, sizeof(int), 0644, NULL, &proc_dointvec},
        {0}
};
 
static ctl_table raid_dir_table[] = {
        {DEV_RAID, "raid", NULL, 0, 0555, raid_table},
        {0}
};
 
static ctl_table raid_root_table[] = {
        {CTL_DEV, "dev", NULL, 0, 0555, raid_dir_table},
        {0}
};
 
/*
 * these have to be allocated separately because external
 * subsystems want to have a pre-defined structure
 */
struct hd_struct md_hd_struct[MAX_MD_DEVS];
static int md_blocksizes[MAX_MD_DEVS];
static int md_hardsect_sizes[MAX_MD_DEVS];
static int md_maxreadahead[MAX_MD_DEVS];
static mdk_thread_t *md_recovery_thread;
 
int md_size[MAX_MD_DEVS];
 
static struct block_device_operations md_fops;
static devfs_handle_t devfs_handle;
 
static struct gendisk md_gendisk=
{
        major: MD_MAJOR,
        major_name: "md",
        minor_shift: 0,
        max_p: 1,
        part: md_hd_struct,
        sizes: md_size,
        nr_real: MAX_MD_DEVS,
        real_devices: NULL,
        next: NULL,
        fops: &md_fops,
};
 
/*
 * Enables to iterate over all existing md arrays
 */
static MD_LIST_HEAD(all_mddevs);
 
/*
 * The mapping between kdev and mddev is not necessary a simple
 * one! Eg. HSM uses several sub-devices to implement Logical
 * Volumes. All these sub-devices map to the same mddev.
 */
dev_mapping_t mddev_map[MAX_MD_DEVS];
 
void add_mddev_mapping(mddev_t * mddev, kdev_t dev, void *data)
{
        unsigned int minor = MINOR(dev);
 
        if (MAJOR(dev) != MD_MAJOR) {
                MD_BUG();
                return;
        }
        if (mddev_map[minor].mddev) {
                MD_BUG();
                return;
        }
        mddev_map[minor].mddev = mddev;
        mddev_map[minor].data = data;
}
 
void del_mddev_mapping(mddev_t * mddev, kdev_t dev)
{
        unsigned int minor = MINOR(dev);
 
        if (MAJOR(dev) != MD_MAJOR) {
                MD_BUG();
                return;
        }
        if (mddev_map[minor].mddev != mddev) {
                MD_BUG();
                return;
        }
        mddev_map[minor].mddev = NULL;
        mddev_map[minor].data = NULL;
}
 
static int md_make_request(request_queue_t *q, int rw, struct buffer_head * bh)
{
        mddev_t *mddev = kdev_to_mddev(bh->b_rdev);
 
        if (mddev && mddev->pers)
                return mddev->pers->make_request(mddev, rw, bh);
        else {
                buffer_IO_error(bh);
                return 0;
        }
}
 
static mddev_t * alloc_mddev(kdev_t dev)
{
        mddev_t *mddev;
 
        if (MAJOR(dev) != MD_MAJOR) {
                MD_BUG();
                return 0;
        }
        mddev = (mddev_t *) kmalloc(sizeof(*mddev), GFP_KERNEL);
        if (!mddev)
                return NULL;
 
        memset(mddev, 0, sizeof(*mddev));
 
        mddev->__minor = MINOR(dev);
        init_MUTEX(&mddev->reconfig_sem);
        init_MUTEX(&mddev->recovery_sem);
        init_MUTEX(&mddev->resync_sem);
        MD_INIT_LIST_HEAD(&mddev->disks);
        MD_INIT_LIST_HEAD(&mddev->all_mddevs);
        atomic_set(&mddev->active, 0);
 
        /*
         * The 'base' mddev is the one with data NULL.
         * personalities can create additional mddevs
         * if necessary.
         */
        add_mddev_mapping(mddev, dev, 0);
        md_list_add(&mddev->all_mddevs, &all_mddevs);
 
        MOD_INC_USE_COUNT;
 
        return mddev;
}
 
mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
{
        mdk_rdev_t * rdev;
        struct md_list_head *tmp;
 
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (rdev->desc_nr == nr)
                        return rdev;
        }
        return NULL;
}
 
mdk_rdev_t * find_rdev(mddev_t * mddev, kdev_t dev)
{
        struct md_list_head *tmp;
        mdk_rdev_t *rdev;
 
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (rdev->dev == dev)
                        return rdev;
        }
        return NULL;
}
 
static MD_LIST_HEAD(device_names);
 
char * partition_name(kdev_t dev)
{
        struct gendisk *hd;
        static char nomem [] = "<nomem>";
        dev_name_t *dname;
        struct md_list_head *tmp = device_names.next;
 
        while (tmp != &device_names) {
                dname = md_list_entry(tmp, dev_name_t, list);
                if (dname->dev == dev)
                        return dname->name;
                tmp = tmp->next;
        }
 
        dname = (dev_name_t *) kmalloc(sizeof(*dname), GFP_KERNEL);
 
        if (!dname)
                return nomem;
        /*
         * ok, add this new device name to the list
         */
        hd = get_gendisk (dev);
        dname->name = NULL;
        if (hd)
                dname->name = disk_name (hd, MINOR(dev), dname->namebuf);
        if (!dname->name) {
                sprintf (dname->namebuf, "[dev %s]", kdevname(dev));
                dname->name = dname->namebuf;
        }
 
        dname->dev = dev;
        MD_INIT_LIST_HEAD(&dname->list);
        md_list_add(&dname->list, &device_names);
 
        return dname->name;
}
 
static unsigned int calc_dev_sboffset(kdev_t dev, mddev_t *mddev,
                                                int persistent)
{
        unsigned int size = 0;
 
        if (blk_size[MAJOR(dev)])
                size = blk_size[MAJOR(dev)][MINOR(dev)];
        if (persistent)
                size = MD_NEW_SIZE_BLOCKS(size);
        return size;
}
 
static unsigned int calc_dev_size(kdev_t dev, mddev_t *mddev, int persistent)
{
        unsigned int size;
 
        size = calc_dev_sboffset(dev, mddev, persistent);
        if (!mddev->sb) {
                MD_BUG();
                return size;
        }
        if (mddev->sb->chunk_size)
                size &= ~(mddev->sb->chunk_size/1024 - 1);
        return size;
}
 
static unsigned int zoned_raid_size(mddev_t *mddev)
{
        unsigned int mask;
        mdk_rdev_t * rdev;
        struct md_list_head *tmp;
 
        if (!mddev->sb) {
                MD_BUG();
                return -EINVAL;
        }
        /*
         * do size and offset calculations.
         */
        mask = ~(mddev->sb->chunk_size/1024 - 1);
 
        ITERATE_RDEV(mddev,rdev,tmp) {
                rdev->size &= mask;
                md_size[mdidx(mddev)] += rdev->size;
        }
        return 0;
}
 
/*
 * We check wether all devices are numbered from 0 to nb_dev-1. The
 * order is guaranteed even after device name changes.
 *
 * Some personalities (raid0, linear) use this. Personalities that
 * provide data have to be able to deal with loss of individual
 * disks, so they do their checking themselves.
 */
int md_check_ordering(mddev_t *mddev)
{
        int i, c;
        mdk_rdev_t *rdev;
        struct md_list_head *tmp;
 
        /*
         * First, all devices must be fully functional
         */
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (rdev->faulty) {
                        printk(KERN_ERR "md: md%d's device %s faulty, aborting.\n",
                               mdidx(mddev), partition_name(rdev->dev));
                        goto abort;
                }
        }
 
        c = 0;
        ITERATE_RDEV(mddev,rdev,tmp) {
                c++;
        }
        if (c != mddev->nb_dev) {
                MD_BUG();
                goto abort;
        }
        if (mddev->nb_dev != mddev->sb->raid_disks) {
                printk(KERN_ERR "md: md%d, array needs %d disks, has %d, aborting.\n",
                        mdidx(mddev), mddev->sb->raid_disks, mddev->nb_dev);
                goto abort;
        }
        /*
         * Now the numbering check
         */
        for (i = 0; i < mddev->nb_dev; i++) {
                c = 0;
                ITERATE_RDEV(mddev,rdev,tmp) {
                        if (rdev->desc_nr == i)
                                c++;
                }
                if (!c) {
                        printk(KERN_ERR "md: md%d, missing disk #%d, aborting.\n",
                               mdidx(mddev), i);
                        goto abort;
                }
                if (c > 1) {
                        printk(KERN_ERR "md: md%d, too many disks #%d, aborting.\n",
                               mdidx(mddev), i);
                        goto abort;
                }
        }
        return 0;
abort:
        return 1;
}
 
static void remove_descriptor(mdp_disk_t *disk, mdp_super_t *sb)
{
        if (disk_active(disk)) {
                sb->working_disks--;
        } else {
                if (disk_spare(disk)) {
                        sb->spare_disks--;
                        sb->working_disks--;
                } else  {
                        sb->failed_disks--;
                }
        }
        sb->nr_disks--;
        disk->major = 0;
        disk->minor = 0;
        mark_disk_removed(disk);
}
 
#define BAD_MAGIC KERN_ERR \
"md: invalid raid superblock magic on %s\n"
 
#define BAD_MINOR KERN_ERR \
"md: %s: invalid raid minor (%x)\n"
 
#define OUT_OF_MEM KERN_ALERT \
"md: out of memory.\n"
 
#define NO_SB KERN_ERR \
"md: disabled device %s, could not read superblock.\n"
 
#define BAD_CSUM KERN_WARNING \
"md: invalid superblock checksum on %s\n"
 
static int alloc_array_sb(mddev_t * mddev)
{
        if (mddev->sb) {
                MD_BUG();
                return 0;
        }
 
        mddev->sb = (mdp_super_t *) __get_free_page (GFP_KERNEL);
        if (!mddev->sb)
                return -ENOMEM;
        md_clear_page(mddev->sb);
        return 0;
}
 
static int alloc_disk_sb(mdk_rdev_t * rdev)
{
        if (rdev->sb)
                MD_BUG();
 
        rdev->sb_page = alloc_page(GFP_KERNEL);
        if (!rdev->sb_page) {
                printk(OUT_OF_MEM);
                return -EINVAL;
        }
        rdev->sb = (mdp_super_t *) page_address(rdev->sb_page);
 
        return 0;
}
 
static void free_disk_sb(mdk_rdev_t * rdev)
{
        if (rdev->sb_page) {
                page_cache_release(rdev->sb_page);
                rdev->sb = NULL;
                rdev->sb_page = NULL;
                rdev->sb_offset = 0;
                rdev->size = 0;
        } else {
                if (!rdev->faulty)
                        MD_BUG();
        }
}
 
 
static void bh_complete(struct buffer_head *bh, int uptodate)
{
 
        if (uptodate)
                set_bit(BH_Uptodate, &bh->b_state);
 
        complete((struct completion*)bh->b_private);
}
 
static int sync_page_io(kdev_t dev, unsigned long sector, int size,
                        struct page *page, int rw)
{
        struct buffer_head bh;
        struct completion event;
 
        init_completion(&event);
        init_buffer(&bh, bh_complete, &event);
        bh.b_rdev = dev;
        bh.b_rsector = sector;
        bh.b_state      = (1 << BH_Req) | (1 << BH_Mapped) | (1 << BH_Lock);
        bh.b_size = size;
        bh.b_page = page;
        bh.b_reqnext = NULL;
        bh.b_data = page_address(page);
        generic_make_request(rw, &bh);
 
        run_task_queue(&tq_disk);
        wait_for_completion(&event);
 
        return test_bit(BH_Uptodate, &bh.b_state);
}
 
static int read_disk_sb(mdk_rdev_t * rdev)
{
        int ret = -EINVAL;
        kdev_t dev = rdev->dev;
        unsigned long sb_offset;
 
        if (!rdev->sb) {
                MD_BUG();
                goto abort;
        }
 
        /*
         * Calculate the position of the superblock,
         * it's at the end of the disk
         */
        sb_offset = calc_dev_sboffset(rdev->dev, rdev->mddev, 1);
        rdev->sb_offset = sb_offset;
 
        if (!sync_page_io(dev, sb_offset<<1, MD_SB_BYTES, rdev->sb_page, READ)) {
                printk(NO_SB,partition_name(dev));
                return -EINVAL;
        }
        printk(KERN_INFO " [events: %08lx]\n", (unsigned long)rdev->sb->events_lo);
        ret = 0;
abort:
        return ret;
}
 
static unsigned int calc_sb_csum(mdp_super_t * sb)
{
        unsigned int disk_csum, csum;
 
        disk_csum = sb->sb_csum;
        sb->sb_csum = 0;
        csum = csum_partial((void *)sb, MD_SB_BYTES, 0);
        sb->sb_csum = disk_csum;
        return csum;
}
 
/*
 * Check one RAID superblock for generic plausibility
 */
 
static int check_disk_sb(mdk_rdev_t * rdev)
{
        mdp_super_t *sb;
        int ret = -EINVAL;
 
        sb = rdev->sb;
        if (!sb) {
                MD_BUG();
                goto abort;
        }
 
        if (sb->md_magic != MD_SB_MAGIC) {
                printk(BAD_MAGIC, partition_name(rdev->dev));
                goto abort;
        }
 
        if (sb->md_minor >= MAX_MD_DEVS) {
                printk(BAD_MINOR, partition_name(rdev->dev), sb->md_minor);
                goto abort;
        }
 
        if (calc_sb_csum(sb) != sb->sb_csum) {
                printk(BAD_CSUM, partition_name(rdev->dev));
                goto abort;
        }
        ret = 0;
abort:
        return ret;
}
 
static kdev_t dev_unit(kdev_t dev)
{
        unsigned int mask;
        struct gendisk *hd = get_gendisk(dev);
 
        if (!hd)
                return 0;
        mask = ~((1 << hd->minor_shift) - 1);
 
        return MKDEV(MAJOR(dev), MINOR(dev) & mask);
}
 
static mdk_rdev_t * match_dev_unit(mddev_t *mddev, kdev_t dev)
{
        struct md_list_head *tmp;
        mdk_rdev_t *rdev;
 
        ITERATE_RDEV(mddev,rdev,tmp)
                if (dev_unit(rdev->dev) == dev_unit(dev))
                        return rdev;
 
        return NULL;
}
 
static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
{
        struct md_list_head *tmp;
        mdk_rdev_t *rdev;
 
        ITERATE_RDEV(mddev1,rdev,tmp)
                if (match_dev_unit(mddev2, rdev->dev))
                        return 1;
 
        return 0;
}
 
static MD_LIST_HEAD(all_raid_disks);
static MD_LIST_HEAD(pending_raid_disks);
 
static void bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
{
        mdk_rdev_t *same_pdev;
 
        if (rdev->mddev) {
                MD_BUG();
                return;
        }
        same_pdev = match_dev_unit(mddev, rdev->dev);
        if (same_pdev)
                printk( KERN_WARNING
"md%d: WARNING: %s appears to be on the same physical disk as %s. True\n"
"     protection against single-disk failure might be compromised.\n",
                        mdidx(mddev), partition_name(rdev->dev),
                                partition_name(same_pdev->dev));
 
        md_list_add(&rdev->same_set, &mddev->disks);
        rdev->mddev = mddev;
        mddev->nb_dev++;
        printk(KERN_INFO "md: bind<%s,%d>\n", partition_name(rdev->dev), mddev->nb_dev);
}
 
static void unbind_rdev_from_array(mdk_rdev_t * rdev)
{
        if (!rdev->mddev) {
                MD_BUG();
                return;
        }
        md_list_del(&rdev->same_set);
        MD_INIT_LIST_HEAD(&rdev->same_set);
        rdev->mddev->nb_dev--;
        printk(KERN_INFO "md: unbind<%s,%d>\n", partition_name(rdev->dev),
                                                 rdev->mddev->nb_dev);
        rdev->mddev = NULL;
}
 
/*
 * prevent the device from being mounted, repartitioned or
 * otherwise reused by a RAID array (or any other kernel
 * subsystem), by opening the device. [simply getting an
 * inode is not enough, the SCSI module usage code needs
 * an explicit open() on the device]
 */
static int lock_rdev(mdk_rdev_t *rdev)
{
        int err = 0;
        struct block_device *bdev;
 
        bdev = bdget(rdev->dev);
        if (!bdev)
                return -ENOMEM;
        err = blkdev_get(bdev, FMODE_READ|FMODE_WRITE, 0, BDEV_RAW);
        if (!err)
                rdev->bdev = bdev;
        return err;
}
 
static void unlock_rdev(mdk_rdev_t *rdev)
{
        struct block_device *bdev = rdev->bdev;
        rdev->bdev = NULL;
        if (!bdev)
                MD_BUG();
        blkdev_put(bdev, BDEV_RAW);
}
 
void md_autodetect_dev(kdev_t dev);
 
static void export_rdev(mdk_rdev_t * rdev)
{
        printk(KERN_INFO "md: export_rdev(%s)\n",partition_name(rdev->dev));
        if (rdev->mddev)
                MD_BUG();
        unlock_rdev(rdev);
        free_disk_sb(rdev);
        md_list_del(&rdev->all);
        MD_INIT_LIST_HEAD(&rdev->all);
        if (rdev->pending.next != &rdev->pending) {
                printk(KERN_INFO "md: (%s was pending)\n",
                        partition_name(rdev->dev));
                md_list_del(&rdev->pending);
                MD_INIT_LIST_HEAD(&rdev->pending);
        }
#ifndef MODULE
        md_autodetect_dev(rdev->dev);
#endif
        rdev->dev = 0;
        rdev->faulty = 0;
        kfree(rdev);
}
 
static void kick_rdev_from_array(mdk_rdev_t * rdev)
{
        unbind_rdev_from_array(rdev);
        export_rdev(rdev);
}
 
static void export_array(mddev_t *mddev)
{
        struct md_list_head *tmp;
        mdk_rdev_t *rdev;
        mdp_super_t *sb = mddev->sb;
 
        if (mddev->sb) {
                mddev->sb = NULL;
                free_page((unsigned long) sb);
        }
 
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (!rdev->mddev) {
                        MD_BUG();
                        continue;
                }
                kick_rdev_from_array(rdev);
        }
        if (mddev->nb_dev)
                MD_BUG();
}
 
static void free_mddev(mddev_t *mddev)
{
        if (!mddev) {
                MD_BUG();
                return;
        }
 
        export_array(mddev);
        md_size[mdidx(mddev)] = 0;
        md_hd_struct[mdidx(mddev)].nr_sects = 0;
 
        /*
         * Make sure nobody else is using this mddev
         * (careful, we rely on the global kernel lock here)
         */
        while (sem_getcount(&mddev->resync_sem) != 1)
                schedule();
        while (sem_getcount(&mddev->recovery_sem) != 1)
                schedule();
 
        del_mddev_mapping(mddev, MKDEV(MD_MAJOR, mdidx(mddev)));
        md_list_del(&mddev->all_mddevs);
        MD_INIT_LIST_HEAD(&mddev->all_mddevs);
        kfree(mddev);
        MOD_DEC_USE_COUNT;
}
 
#undef BAD_CSUM
#undef BAD_MAGIC
#undef OUT_OF_MEM
#undef NO_SB
 
static void print_desc(mdp_disk_t *desc)
{
        printk(" DISK<N:%d,%s(%d,%d),R:%d,S:%d>\n", desc->number,
                partition_name(MKDEV(desc->major,desc->minor)),
                desc->major,desc->minor,desc->raid_disk,desc->state);
}
 
static void print_sb(mdp_super_t *sb)
{
        int i;
 
        printk(KERN_INFO "md:  SB: (V:%d.%d.%d) ID:<%08x.%08x.%08x.%08x> CT:%08x\n",
                sb->major_version, sb->minor_version, sb->patch_version,
                sb->set_uuid0, sb->set_uuid1, sb->set_uuid2, sb->set_uuid3,
                sb->ctime);
        printk(KERN_INFO "md:     L%d S%08d ND:%d RD:%d md%d LO:%d CS:%d\n", sb->level,
                sb->size, sb->nr_disks, sb->raid_disks, sb->md_minor,
                sb->layout, sb->chunk_size);
        printk(KERN_INFO "md:     UT:%08x ST:%d AD:%d WD:%d FD:%d SD:%d CSUM:%08x E:%08lx\n",
                sb->utime, sb->state, sb->active_disks, sb->working_disks,
                sb->failed_disks, sb->spare_disks,
                sb->sb_csum, (unsigned long)sb->events_lo);
 
        printk(KERN_INFO);
        for (i = 0; i < MD_SB_DISKS; i++) {
                mdp_disk_t *desc;
 
                desc = sb->disks + i;
                if (desc->number || desc->major || desc->minor ||
                    desc->raid_disk || (desc->state && (desc->state != 4))) {
                        printk("     D %2d: ", i);
                        print_desc(desc);
                }
        }
        printk(KERN_INFO "md:     THIS: ");
        print_desc(&sb->this_disk);
 
}
 
static void print_rdev(mdk_rdev_t *rdev)
{
        printk(KERN_INFO "md: rdev %s: O:%s, SZ:%08ld F:%d DN:%d ",
                partition_name(rdev->dev), partition_name(rdev->old_dev),
                rdev->size, rdev->faulty, rdev->desc_nr);
        if (rdev->sb) {
                printk(KERN_INFO "md: rdev superblock:\n");
                print_sb(rdev->sb);
        } else
                printk(KERN_INFO "md: no rdev superblock!\n");
}
 
void md_print_devices(void)
{
        struct md_list_head *tmp, *tmp2;
        mdk_rdev_t *rdev;
        mddev_t *mddev;
 
        printk("\n");
        printk("md:     **********************************\n");
        printk("md:     * <COMPLETE RAID STATE PRINTOUT> *\n");
        printk("md:     **********************************\n");
        ITERATE_MDDEV(mddev,tmp) {
                printk("md%d: ", mdidx(mddev));
 
                ITERATE_RDEV(mddev,rdev,tmp2)
                        printk("<%s>", partition_name(rdev->dev));
 
                if (mddev->sb) {
                        printk(" array superblock:\n");
                        print_sb(mddev->sb);
                } else
                        printk(" no array superblock.\n");
 
                ITERATE_RDEV(mddev,rdev,tmp2)
                        print_rdev(rdev);
        }
        printk("md:     **********************************\n");
        printk("\n");
}
 
static int sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
{
        int ret;
        mdp_super_t *tmp1, *tmp2;
 
        tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
        tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
 
        if (!tmp1 || !tmp2) {
                ret = 0;
                printk(KERN_INFO "md.c: sb1 is not equal to sb2!\n");
                goto abort;
        }
 
        *tmp1 = *sb1;
        *tmp2 = *sb2;
 
        /*
         * nr_disks is not constant
         */
        tmp1->nr_disks = 0;
        tmp2->nr_disks = 0;
 
        if (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4))
                ret = 0;
        else
                ret = 1;
 
abort:
        if (tmp1)
                kfree(tmp1);
        if (tmp2)
                kfree(tmp2);
 
        return ret;
}
 
static int uuid_equal(mdk_rdev_t *rdev1, mdk_rdev_t *rdev2)
{
        if (    (rdev1->sb->set_uuid0 == rdev2->sb->set_uuid0) &&
                (rdev1->sb->set_uuid1 == rdev2->sb->set_uuid1) &&
                (rdev1->sb->set_uuid2 == rdev2->sb->set_uuid2) &&
                (rdev1->sb->set_uuid3 == rdev2->sb->set_uuid3))
 
                return 1;
 
        return 0;
}
 
static mdk_rdev_t * find_rdev_all(kdev_t dev)
{
        struct md_list_head *tmp;
        mdk_rdev_t *rdev;
 
        tmp = all_raid_disks.next;
        while (tmp != &all_raid_disks) {
                rdev = md_list_entry(tmp, mdk_rdev_t, all);
                if (rdev->dev == dev)
                        return rdev;
                tmp = tmp->next;
        }
        return NULL;
}
 
#define GETBLK_FAILED KERN_ERR \
"md: getblk failed for device %s\n"
 
static int write_disk_sb(mdk_rdev_t * rdev)
{
        kdev_t dev;
        unsigned long sb_offset, size;
 
        if (!rdev->sb) {
                MD_BUG();
                return 1;
        }
        if (rdev->faulty) {
                MD_BUG();
                return 1;
        }
        if (rdev->sb->md_magic != MD_SB_MAGIC) {
                MD_BUG();
                return 1;
        }
 
        dev = rdev->dev;
        sb_offset = calc_dev_sboffset(dev, rdev->mddev, 1);
        if (rdev->sb_offset != sb_offset) {
                printk(KERN_INFO "%s's sb offset has changed from %ld to %ld, skipping\n",
                       partition_name(dev), rdev->sb_offset, sb_offset);
                goto skip;
        }
        /*
         * If the disk went offline meanwhile and it's just a spare, then
         * its size has changed to zero silently, and the MD code does
         * not yet know that it's faulty.
         */
        size = calc_dev_size(dev, rdev->mddev, 1);
        if (size != rdev->size) {
                printk(KERN_INFO "%s's size has changed from %ld to %ld since import, skipping\n",
                       partition_name(dev), rdev->size, size);
                goto skip;
        }
 
        printk(KERN_INFO "(write) %s's sb offset: %ld\n", partition_name(dev), sb_offset);
 
        if (!sync_page_io(dev, sb_offset<<1, MD_SB_BYTES, rdev->sb_page, WRITE)) {
                printk("md: write_disk_sb failed for device %s\n", partition_name(dev));
                return 1;
        }
skip:
        return 0;
}
#undef GETBLK_FAILED
 
static void set_this_disk(mddev_t *mddev, mdk_rdev_t *rdev)
{
        int i, ok = 0;
        mdp_disk_t *desc;
 
        for (i = 0; i < MD_SB_DISKS; i++) {
                desc = mddev->sb->disks + i;
#if 0
                if (disk_faulty(desc)) {
                        if (MKDEV(desc->major,desc->minor) == rdev->dev)
                                ok = 1;
                        continue;
                }
#endif
                if (MKDEV(desc->major,desc->minor) == rdev->dev) {
                        rdev->sb->this_disk = *desc;
                        rdev->desc_nr = desc->number;
                        ok = 1;
                        break;
                }
        }
 
        if (!ok) {
                MD_BUG();
        }
}
 
static int sync_sbs(mddev_t * mddev)
{
        mdk_rdev_t *rdev;
        mdp_super_t *sb;
        struct md_list_head *tmp;
 
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (rdev->faulty || rdev->alias_device)
                        continue;
                sb = rdev->sb;
                *sb = *mddev->sb;
                set_this_disk(mddev, rdev);
                sb->sb_csum = calc_sb_csum(sb);
        }
        return 0;
}
 
int md_update_sb(mddev_t * mddev)
{
        int err, count = 100;
        struct md_list_head *tmp;
        mdk_rdev_t *rdev;
 
        if (!mddev->sb_dirty) {
                printk("hm, md_update_sb() called without ->sb_dirty == 1, from %p.\n", __builtin_return_address(0));
                return 0;
        }
        mddev->sb_dirty = 0;
repeat:
        mddev->sb->utime = CURRENT_TIME;
        if ((++mddev->sb->events_lo)==0)
                ++mddev->sb->events_hi;
 
        if ((mddev->sb->events_lo|mddev->sb->events_hi)==0) {
                /*
                 * oops, this 64-bit counter should never wrap.
                 * Either we are in around ~1 trillion A.C., assuming
                 * 1 reboot per second, or we have a bug:
                 */
                MD_BUG();
                mddev->sb->events_lo = mddev->sb->events_hi = 0xffffffff;
        }
        sync_sbs(mddev);
 
        /*
         * do not write anything to disk if using
         * nonpersistent superblocks
         */
        if (mddev->sb->not_persistent)
                return 0;
 
        printk(KERN_INFO "md: updating md%d RAID superblock on device\n",
                                        mdidx(mddev));
 
        err = 0;
        ITERATE_RDEV(mddev,rdev,tmp) {
                printk(KERN_INFO "md: ");
                if (rdev->faulty)
                        printk("(skipping faulty ");
                if (rdev->alias_device)
                        printk("(skipping alias ");
                if (!rdev->faulty && disk_faulty(&rdev->sb->this_disk)) {
                        printk("(skipping new-faulty %s )\n",
                               partition_name(rdev->dev));
                        continue;
                }
                printk("%s ", partition_name(rdev->dev));
                if (!rdev->faulty && !rdev->alias_device) {
                        printk("[events: %08lx]",
                                (unsigned long)rdev->sb->events_lo);
                        err += write_disk_sb(rdev);
                } else
                        printk(")\n");
        }
        if (err) {
                if (--count) {
                        printk(KERN_ERR "md: errors occurred during superblock update, repeating\n");
                        goto repeat;
                }
                printk(KERN_ERR "md: excessive errors occurred during superblock update, exiting\n");
        }
        return 0;
}
 
/*
 * Import a device. If 'on_disk', then sanity check the superblock
 *
 * mark the device faulty if:
 *
 *   - the device is nonexistent (zero size)
 *   - the device has no valid superblock
 *
 */
static int md_import_device(kdev_t newdev, int on_disk)
{
        int err;
        mdk_rdev_t *rdev;
        unsigned int size;
 
        if (find_rdev_all(newdev))
                return -EEXIST;
 
        rdev = (mdk_rdev_t *) kmalloc(sizeof(*rdev), GFP_KERNEL);
        if (!rdev) {
                printk(KERN_ERR "md: could not alloc mem for %s!\n", partition_name(newdev));
                return -ENOMEM;
        }
        memset(rdev, 0, sizeof(*rdev));
 
        if (is_mounted(newdev)) {
                printk(KERN_WARNING "md: can not import %s, has active inodes!\n",
                        partition_name(newdev));
                err = -EBUSY;
                goto abort_free;
        }
 
        if ((err = alloc_disk_sb(rdev)))
                goto abort_free;
 
        rdev->dev = newdev;
        if (lock_rdev(rdev)) {
                printk(KERN_ERR "md: could not lock %s, zero-size? Marking faulty.\n",
                        partition_name(newdev));
                err = -EINVAL;
                goto abort_free;
        }
        rdev->desc_nr = -1;
        rdev->faulty = 0;
 
        size = 0;
        if (blk_size[MAJOR(newdev)])
                size = blk_size[MAJOR(newdev)][MINOR(newdev)];
        if (!size) {
                printk(KERN_WARNING "md: %s has zero size, marking faulty!\n",
                                partition_name(newdev));
                err = -EINVAL;
                goto abort_free;
        }
 
        if (on_disk) {
                if ((err = read_disk_sb(rdev))) {
                        printk(KERN_WARNING "md: could not read %s's sb, not importing!\n",
                               partition_name(newdev));
                        goto abort_free;
                }
                if ((err = check_disk_sb(rdev))) {
                        printk(KERN_WARNING "md: %s has invalid sb, not importing!\n",
                               partition_name(newdev));
                        goto abort_free;
                }
 
                if (rdev->sb->level != -4) {
                        rdev->old_dev = MKDEV(rdev->sb->this_disk.major,
                                                rdev->sb->this_disk.minor);
                        rdev->desc_nr = rdev->sb->this_disk.number;
                } else {
                        rdev->old_dev = MKDEV(0, 0);
                        rdev->desc_nr = -1;
                }
        }
        md_list_add(&rdev->all, &all_raid_disks);
        MD_INIT_LIST_HEAD(&rdev->pending);
 
        return 0;
 
abort_free:
        if (rdev->sb) {
                if (rdev->bdev)
                        unlock_rdev(rdev);
                free_disk_sb(rdev);
        }
        kfree(rdev);
        return err;
}
 
/*
 * Check a full RAID array for plausibility
 */
 
#define INCONSISTENT KERN_ERR \
"md: fatal superblock inconsistency in %s -- removing from array\n"
 
#define OUT_OF_DATE KERN_ERR \
"md: superblock update time inconsistency -- using the most recent one\n"
 
#define OLD_VERSION KERN_ALERT \
"md: md%d: unsupported raid array version %d.%d.%d\n"
 
#define NOT_CLEAN_IGNORE KERN_ERR \
"md: md%d: raid array is not clean -- starting background reconstruction\n"
 
#define UNKNOWN_LEVEL KERN_ERR \
"md: md%d: unsupported raid level %d\n"
 
static int analyze_sbs(mddev_t * mddev)
{
        int out_of_date = 0, i, first;
        struct md_list_head *tmp, *tmp2;
        mdk_rdev_t *rdev, *rdev2, *freshest;
        mdp_super_t *sb;
 
        /*
         * Verify the RAID superblock on each real device
         */
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (rdev->faulty) {
                        MD_BUG();
                        goto abort;
                }
                if (!rdev->sb) {
                        MD_BUG();
                        goto abort;
                }
                if (check_disk_sb(rdev))
                        goto abort;
        }
 
        /*
         * The superblock constant part has to be the same
         * for all disks in the array.
         */
        sb = NULL;
 
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (!sb) {
                        sb = rdev->sb;
                        continue;
                }
                if (!sb_equal(sb, rdev->sb)) {
                        printk(INCONSISTENT, partition_name(rdev->dev));
                        kick_rdev_from_array(rdev);
                        continue;
                }
        }
 
        /*
         * OK, we have all disks and the array is ready to run. Let's
         * find the freshest superblock, that one will be the superblock
         * that represents the whole array.
         */
        if (!mddev->sb)
                if (alloc_array_sb(mddev))
                        goto abort;
        sb = mddev->sb;
        freshest = NULL;
 
        ITERATE_RDEV(mddev,rdev,tmp) {
                __u64 ev1, ev2;
                /*
                 * if the checksum is invalid, use the superblock
                 * only as a last resort. (decrease it's age by
                 * one event)
                 */
                if (calc_sb_csum(rdev->sb) != rdev->sb->sb_csum) {
                        if (rdev->sb->events_lo || rdev->sb->events_hi)
                                if ((rdev->sb->events_lo--)==0)
                                        rdev->sb->events_hi--;
                }
 
                printk(KERN_INFO "md: %s's event counter: %08lx\n",
                       partition_name(rdev->dev),
                        (unsigned long)rdev->sb->events_lo);
                if (!freshest) {
                        freshest = rdev;
                        continue;
                }
                /*
                 * Find the newest superblock version
                 */
                ev1 = md_event(rdev->sb);
                ev2 = md_event(freshest->sb);
                if (ev1 != ev2) {
                        out_of_date = 1;
                        if (ev1 > ev2)
                                freshest = rdev;
                }
        }
        if (out_of_date) {
                printk(OUT_OF_DATE);
                printk(KERN_INFO "md: freshest: %s\n", partition_name(freshest->dev));
        }
        memcpy (sb, freshest->sb, sizeof(*sb));
 
        /*
         * at this point we have picked the 'best' superblock
         * from all available superblocks.
         * now we validate this superblock and kick out possibly
         * failed disks.
         */
        ITERATE_RDEV(mddev,rdev,tmp) {
                /*
                 * Kick all non-fresh devices
                 */
                __u64 ev1, ev2;
                ev1 = md_event(rdev->sb);
                ev2 = md_event(sb);
                ++ev1;
                if (ev1 < ev2) {
                        printk(KERN_WARNING "md: kicking non-fresh %s from array!\n",
                                                partition_name(rdev->dev));
                        kick_rdev_from_array(rdev);
                        continue;
                }
        }
 
        /*
         * Fix up changed device names ... but only if this disk has a
         * recent update time. Use faulty checksum ones too.
         */
        if (mddev->sb->level != -4)
        ITERATE_RDEV(mddev,rdev,tmp) {
                __u64 ev1, ev2, ev3;
                if (rdev->faulty || rdev->alias_device) {
                        MD_BUG();
                        goto abort;
                }
                ev1 = md_event(rdev->sb);
                ev2 = md_event(sb);
                ev3 = ev2;
                --ev3;
                if ((rdev->dev != rdev->old_dev) &&
                        ((ev1 == ev2) || (ev1 == ev3))) {
                        mdp_disk_t *desc;
 
                        printk(KERN_WARNING "md: device name has changed from %s to %s since last import!\n",
                               partition_name(rdev->old_dev), partition_name(rdev->dev));
                        if (rdev->desc_nr == -1) {
                                MD_BUG();
                                goto abort;
                        }
                        desc = &sb->disks[rdev->desc_nr];
                        if (rdev->old_dev != MKDEV(desc->major, desc->minor)) {
                                MD_BUG();
                                goto abort;
                        }
                        desc->major = MAJOR(rdev->dev);
                        desc->minor = MINOR(rdev->dev);
                        desc = &rdev->sb->this_disk;
                        desc->major = MAJOR(rdev->dev);
                        desc->minor = MINOR(rdev->dev);
                }
        }
 
        /*
         * Remove unavailable and faulty devices ...
         *
         * note that if an array becomes completely unrunnable due to
         * missing devices, we do not write the superblock back, so the
         * administrator has a chance to fix things up. The removal thus
         * only happens if it's nonfatal to the contents of the array.
         */
        for (i = 0; i < MD_SB_DISKS; i++) {
                int found;
                mdp_disk_t *desc;
                kdev_t dev;
 
                desc = sb->disks + i;
                dev = MKDEV(desc->major, desc->minor);
 
                /*
                 * We kick faulty devices/descriptors immediately.
                 *
                 * Note: multipath devices are a special case.  Since we
                 * were able to read the superblock on the path, we don't
                 * care if it was previously marked as faulty, it's up now
                 * so enable it.
                 */
                if (disk_faulty(desc) && mddev->sb->level != -4) {
                        found = 0;
                        ITERATE_RDEV(mddev,rdev,tmp) {
                                if (rdev->desc_nr != desc->number)
                                        continue;
                                printk(KERN_WARNING "md%d: kicking faulty %s!\n",
                                        mdidx(mddev),partition_name(rdev->dev));
                                kick_rdev_from_array(rdev);
                                found = 1;
                                break;
                        }
                        if (!found) {
                                if (dev == MKDEV(0,0))
                                        continue;
                                printk(KERN_WARNING "md%d: removing former faulty %s!\n",
                                        mdidx(mddev), partition_name(dev));
                        }
                        remove_descriptor(desc, sb);
                        continue;
                } else if (disk_faulty(desc)) {
                        /*
                         * multipath entry marked as faulty, unfaulty it
                         */
                        rdev = find_rdev(mddev, dev);
                        if(rdev)
                                mark_disk_spare(desc);
                        else
                                remove_descriptor(desc, sb);
                }
 
                if (dev == MKDEV(0,0))
                        continue;
                /*
                 * Is this device present in the rdev ring?
                 */
                found = 0;
                ITERATE_RDEV(mddev,rdev,tmp) {
                        /*
                         * Multi-path IO special-case: since we have no
                         * this_disk descriptor at auto-detect time,
                         * we cannot check rdev->number.
                         * We can check the device though.
                         */
                        if ((sb->level == -4) && (rdev->dev ==
                                        MKDEV(desc->major,desc->minor))) {
                                found = 1;
                                break;
                        }
                        if (rdev->desc_nr == desc->number) {
                                found = 1;
                                break;
                        }
                }
                if (found)
                        continue;
 
                printk(KERN_WARNING "md%d: former device %s is unavailable, removing from array!\n",
                       mdidx(mddev), partition_name(dev));
                remove_descriptor(desc, sb);
        }
 
        /*
         * Double check wether all devices mentioned in the
         * superblock are in the rdev ring.
         */
        first = 1;
        for (i = 0; i < MD_SB_DISKS; i++) {
                mdp_disk_t *desc;
                kdev_t dev;
 
                desc = sb->disks + i;
                dev = MKDEV(desc->major, desc->minor);
 
                if (dev == MKDEV(0,0))
                        continue;
 
                if (disk_faulty(desc)) {
                        MD_BUG();
                        goto abort;
                }
 
                rdev = find_rdev(mddev, dev);
                if (!rdev) {
                        MD_BUG();
                        goto abort;
                }
                /*
                 * In the case of Multipath-IO, we have no
                 * other information source to find out which
                 * disk is which, only the position of the device
                 * in the superblock:
                 */
                if (mddev->sb->level == -4) {
                        if ((rdev->desc_nr != -1) && (rdev->desc_nr != i)) {
                                MD_BUG();
                                goto abort;
                        }
                        rdev->desc_nr = i;
                        if (!first)
                                rdev->alias_device = 1;
                        else
                                first = 0;
                }
        }
 
        /*
         * Kick all rdevs that are not in the
         * descriptor array:
         */
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (rdev->desc_nr == -1)
                        kick_rdev_from_array(rdev);
        }
 
        /*
         * Do a final reality check.
         */
        if (mddev->sb->level != -4) {
                ITERATE_RDEV(mddev,rdev,tmp) {
                        if (rdev->desc_nr == -1) {
                                MD_BUG();
                                goto abort;
                        }
                        /*
                         * is the desc_nr unique?
                         */
                        ITERATE_RDEV(mddev,rdev2,tmp2) {
                                if ((rdev2 != rdev) &&
                                                (rdev2->desc_nr == rdev->desc_nr)) {
                                        MD_BUG();
                                        goto abort;
                                }
                        }
                        /*
                         * is the device unique?
                         */
                        ITERATE_RDEV(mddev,rdev2,tmp2) {
                                if ((rdev2 != rdev) &&
                                                (rdev2->dev == rdev->dev)) {
                                        MD_BUG();
                                        goto abort;
                                }
                        }
                }
        }
 
        /*
         * Check if we can support this RAID array
         */
        if (sb->major_version != MD_MAJOR_VERSION ||
                        sb->minor_version > MD_MINOR_VERSION) {
 
                printk(OLD_VERSION, mdidx(mddev), sb->major_version,
                                sb->minor_version, sb->patch_version);
                goto abort;
        }
 
        if ((sb->state != (1 << MD_SB_CLEAN)) && ((sb->level == 1) ||
                        (sb->level == 4) || (sb->level == 5)))
                printk(NOT_CLEAN_IGNORE, mdidx(mddev));
 
        return 0;
abort:
        return 1;
}
 
#undef INCONSISTENT
#undef OUT_OF_DATE
#undef OLD_VERSION
#undef OLD_LEVEL
 
static int device_size_calculation(mddev_t * mddev)
{
        int data_disks = 0, persistent;
        unsigned int readahead;
        mdp_super_t *sb = mddev->sb;
        struct md_list_head *tmp;
        mdk_rdev_t *rdev;
 
        /*
         * Do device size calculation. Bail out if too small.
         * (we have to do this after having validated chunk_size,
         * because device size has to be modulo chunk_size)
         */
        persistent = !mddev->sb->not_persistent;
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (rdev->faulty)
                        continue;
                if (rdev->size) {
                        MD_BUG();
                        continue;
                }
                rdev->size = calc_dev_size(rdev->dev, mddev, persistent);
                if (rdev->size < sb->chunk_size / 1024) {
                        printk(KERN_WARNING
                                "md: Dev %s smaller than chunk_size: %ldk < %dk\n",
                                partition_name(rdev->dev),
                                rdev->size, sb->chunk_size / 1024);
                        return -EINVAL;
                }
        }
 
        switch (sb->level) {
                case -4:
                        data_disks = 1;
                        break;
                case -3:
                        data_disks = 1;
                        break;
                case -2:
                        data_disks = 1;
                        break;
                case -1:
                        zoned_raid_size(mddev);
                        data_disks = 1;
                        break;
                case 0:
                        zoned_raid_size(mddev);
                        data_disks = sb->raid_disks;
                        break;
                case 1:
                        data_disks = 1;
                        break;
                case 4:
                case 5:
                        data_disks = sb->raid_disks-1;
                        break;
                default:
                        printk(UNKNOWN_LEVEL, mdidx(mddev), sb->level);
                        goto abort;
        }
        if (!md_size[mdidx(mddev)])
                md_size[mdidx(mddev)] = sb->size * data_disks;
 
        readahead = MD_READAHEAD;
        if ((sb->level == 0) || (sb->level == 4) || (sb->level == 5)) {
                readahead = (mddev->sb->chunk_size>>PAGE_SHIFT) * 4 * data_disks;
                if (readahead < data_disks * (MAX_SECTORS>>(PAGE_SHIFT-9))*2)
                        readahead = data_disks * (MAX_SECTORS>>(PAGE_SHIFT-9))*2;
        } else {
                // (no multipath branch - it uses the default setting)
                if (sb->level == -3)
                        readahead = 0;
        }
        md_maxreadahead[mdidx(mddev)] = readahead;
 
        printk(KERN_INFO "md%d: max total readahead window set to %ldk\n",
                mdidx(mddev), readahead*(PAGE_SIZE/1024));
 
        printk(KERN_INFO
                "md%d: %d data-disks, max readahead per data-disk: %ldk\n",
                        mdidx(mddev), data_disks, readahead/data_disks*(PAGE_SIZE/1024));
        return 0;
abort:
        return 1;
}
 
 
#define TOO_BIG_CHUNKSIZE KERN_ERR \
"too big chunk_size: %d > %d\n"
 
#define TOO_SMALL_CHUNKSIZE KERN_ERR \
"too small chunk_size: %d < %ld\n"
 
#define BAD_CHUNKSIZE KERN_ERR \
"no chunksize specified, see 'man raidtab'\n"
 
static int do_md_run(mddev_t * mddev)
{
        int pnum, err;
        int chunk_size;
        struct md_list_head *tmp;
        mdk_rdev_t *rdev;
 
 
        if (!mddev->nb_dev) {
                MD_BUG();
                return -EINVAL;
        }
 
        if (mddev->pers)
                return -EBUSY;
 
        /*
         * Resize disks to align partitions size on a given
         * chunk size.
         */
        md_size[mdidx(mddev)] = 0;
 
        /*
         * Analyze all RAID superblock(s)
         */
        if (analyze_sbs(mddev)) {
                MD_BUG();
                return -EINVAL;
        }
 
        chunk_size = mddev->sb->chunk_size;
        pnum = level_to_pers(mddev->sb->level);
 
        mddev->param.chunk_size = chunk_size;
        mddev->param.personality = pnum;
 
        if ((pnum != MULTIPATH) && (pnum != RAID1)) {
                if (!chunk_size) {
                        /*
                         * 'default chunksize' in the old md code used to
                         * be PAGE_SIZE, baaad.
                         * we abort here to be on the safe side. We dont
                         * want to continue the bad practice.
                         */
                        printk(BAD_CHUNKSIZE);
                        return -EINVAL;
                }
                if (chunk_size > MAX_CHUNK_SIZE) {
                        printk(TOO_BIG_CHUNKSIZE, chunk_size, MAX_CHUNK_SIZE);
                        return -EINVAL;
                }
                /*
                 * chunk-size has to be a power of 2 and multiples of PAGE_SIZE
                 */
                if ( (1 << ffz(~chunk_size)) != chunk_size) {
                        MD_BUG();
                        return -EINVAL;
                }
                if (chunk_size < PAGE_SIZE) {
                        printk(TOO_SMALL_CHUNKSIZE, chunk_size, PAGE_SIZE);
                        return -EINVAL;
                }
        } else
                if (chunk_size)
                        printk(KERN_INFO "md: RAID level %d does not need chunksize! Continuing anyway.\n",
                               mddev->sb->level);
 
        if (pnum >= MAX_PERSONALITY) {
                MD_BUG();
                return -EINVAL;
        }
 
        if (!pers[pnum])
        {
#ifdef CONFIG_KMOD
                char module_name[80];
                sprintf (module_name, "md-personality-%d", pnum);
                request_module (module_name);
                if (!pers[pnum])
#endif
                {
                        printk(KERN_ERR "md: personality %d is not loaded!\n",
                                pnum);
                        return -EINVAL;
                }
        }
 
        if (device_size_calculation(mddev))
                return -EINVAL;
 
        /*
         * Drop all container device buffers, from now on
         * the only valid external interface is through the md
         * device.
         * Also find largest hardsector size
         */
        md_hardsect_sizes[mdidx(mddev)] = 512;
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (rdev->faulty)
                        continue;
                invalidate_device(rdev->dev, 1);
                if (get_hardsect_size(rdev->dev)
                        > md_hardsect_sizes[mdidx(mddev)])
                        md_hardsect_sizes[mdidx(mddev)] =
                                get_hardsect_size(rdev->dev);
        }
        md_blocksizes[mdidx(mddev)] = 1024;
        if (md_blocksizes[mdidx(mddev)] < md_hardsect_sizes[mdidx(mddev)])
                md_blocksizes[mdidx(mddev)] = md_hardsect_sizes[mdidx(mddev)];
        mddev->pers = pers[pnum];
 
        err = mddev->pers->run(mddev);
        if (err) {
                printk(KERN_ERR "md: pers->run() failed ...\n");
                mddev->pers = NULL;
                return -EINVAL;
        }
 
        mddev->sb->state &= ~(1 << MD_SB_CLEAN);
        mddev->sb_dirty = 1;
        md_update_sb(mddev);
 
        /*
         * md_size has units of 1K blocks, which are
         * twice as large as sectors.
         */
        md_hd_struct[mdidx(mddev)].start_sect = 0;
        register_disk(&md_gendisk, MKDEV(MAJOR_NR,mdidx(mddev)),
                        1, &md_fops, md_size[mdidx(mddev)]<<1);
 
        read_ahead[MD_MAJOR] = 1024;
        return (0);
}
 
#undef TOO_BIG_CHUNKSIZE
#undef BAD_CHUNKSIZE
 
#define OUT(x) do { err = (x); goto out; } while (0)
 
static int restart_array(mddev_t *mddev)
{
        int err = 0;
 
        /*
         * Complain if it has no devices
         */
        if (!mddev->nb_dev)
                OUT(-ENXIO);
 
        if (mddev->pers) {
                if (!mddev->ro)
                        OUT(-EBUSY);
 
                mddev->ro = 0;
                set_device_ro(mddev_to_kdev(mddev), 0);
 
                printk(KERN_INFO
                        "md: md%d switched to read-write mode.\n", mdidx(mddev));
                /*
                 * Kick recovery or resync if necessary
                 */
                md_recover_arrays();
                if (mddev->pers->restart_resync)
                        mddev->pers->restart_resync(mddev);
        } else {
                printk(KERN_ERR "md: md%d has no personality assigned.\n",
                        mdidx(mddev));
                err = -EINVAL;
        }
 
out:
        return err;
}
 
#define STILL_MOUNTED KERN_WARNING \
"md: md%d still mounted.\n"
#define STILL_IN_USE \
"md: md%d still in use.\n"
 
static int do_md_stop(mddev_t * mddev, int ro)
{
        int err = 0, resync_interrupted = 0;
        kdev_t dev = mddev_to_kdev(mddev);
 
#if 0 /* ->active is not currently reliable */
        if (atomic_read(&mddev->active)>1) {
                printk(STILL_IN_USE, mdidx(mddev));
                OUT(-EBUSY);
        }
#endif
 
        if (mddev->pers) {
                /*
                 * It is safe to call stop here, it only frees private
                 * data. Also, it tells us if a device is unstoppable
                 * (eg. resyncing is in progress)
                 */
                if (mddev->pers->stop_resync)
                        if (mddev->pers->stop_resync(mddev))
                                resync_interrupted = 1;
 
                if (mddev->recovery_running)
                        md_interrupt_thread(md_recovery_thread);
 
                /*
                 * This synchronizes with signal delivery to the
                 * resync or reconstruction thread. It also nicely
                 * hangs the process if some reconstruction has not
                 * finished.
                 */
                down(&mddev->recovery_sem);
                up(&mddev->recovery_sem);
 
                invalidate_device(dev, 1);
 
                if (ro) {
                        if (mddev->ro)
                                OUT(-ENXIO);
                        mddev->ro = 1;
                } else {
                        if (mddev->ro)
                                set_device_ro(dev, 0);
                        if (mddev->pers->stop(mddev)) {
                                if (mddev->ro)
                                        set_device_ro(dev, 1);
                                OUT(-EBUSY);
                        }
                        if (mddev->ro)
                                mddev->ro = 0;
                }
                if (mddev->sb) {
                        /*
                         * mark it clean only if there was no resync
                         * interrupted.
                         */
                        if (!mddev->recovery_running && !resync_interrupted) {
                                printk(KERN_INFO "md: marking sb clean...\n");
                                mddev->sb->state |= 1 << MD_SB_CLEAN;
                        }
                        mddev->sb_dirty = 1;
                        md_update_sb(mddev);
                }
                if (ro)
                        set_device_ro(dev, 1);
        }
 
        /*
         * Free resources if final stop
         */
        if (!ro) {
                printk(KERN_INFO "md: md%d stopped.\n", mdidx(mddev));
                free_mddev(mddev);
 
        } else
                printk(KERN_INFO "md: md%d switched to read-only mode.\n", mdidx(mddev));
out:
        return err;
}
 
#undef OUT
 
/*
 * We have to safely support old arrays too.
 */
int detect_old_array(mdp_super_t *sb)
{
        if (sb->major_version > 0)
                return 0;
        if (sb->minor_version >= 90)
                return 0;
 
        return -EINVAL;
}
 
 
static void autorun_array(mddev_t *mddev)
{
        mdk_rdev_t *rdev;
        struct md_list_head *tmp;
        int err;
 
        if (mddev->disks.prev == &mddev->disks) {
                MD_BUG();
                return;
        }
 
        printk(KERN_INFO "md: running: ");
 
        ITERATE_RDEV(mddev,rdev,tmp) {
                printk("<%s>", partition_name(rdev->dev));
        }
        printk("\n");
 
        err = do_md_run (mddev);
        if (err) {
                printk(KERN_WARNING "md :do_md_run() returned %d\n", err);
                /*
                 * prevent the writeback of an unrunnable array
                 */
                mddev->sb_dirty = 0;
                do_md_stop (mddev, 0);
        }
}
 
/*
 * lets try to run arrays based on all disks that have arrived
 * until now. (those are in the ->pending list)
 *
 * the method: pick the first pending disk, collect all disks with
 * the same UUID, remove all from the pending list and put them into
 * the 'same_array' list. Then order this list based on superblock
 * update time (freshest comes first), kick out 'old' disks and
 * compare superblocks. If everything's fine then run it.
 *
 * If "unit" is allocated, then bump its reference count
 */
static void autorun_devices(kdev_t countdev)
{
        struct md_list_head candidates;
        struct md_list_head *tmp;
        mdk_rdev_t *rdev0, *rdev;
        mddev_t *mddev;
        kdev_t md_kdev;
 
 
        printk(KERN_INFO "md: autorun ...\n");
        while (pending_raid_disks.next != &pending_raid_disks) {
                rdev0 = md_list_entry(pending_raid_disks.next,
                                         mdk_rdev_t, pending);
 
                printk(KERN_INFO "md: considering %s ...\n", partition_name(rdev0->dev));
                MD_INIT_LIST_HEAD(&candidates);
                ITERATE_RDEV_PENDING(rdev,tmp) {
                        if (uuid_equal(rdev0, rdev)) {
                                if (!sb_equal(rdev0->sb, rdev->sb)) {
                                        printk(KERN_WARNING
                                               "md: %s has same UUID as %s, but superblocks differ ...\n",
                                               partition_name(rdev->dev), partition_name(rdev0->dev));
                                        continue;
                                }
                                printk(KERN_INFO "md:  adding %s ...\n", partition_name(rdev->dev));
                                md_list_del(&rdev->pending);
                                md_list_add(&rdev->pending, &candidates);
                        }
                }
                /*
                 * now we have a set of devices, with all of them having
                 * mostly sane superblocks. It's time to allocate the
                 * mddev.
                 */
                md_kdev = MKDEV(MD_MAJOR, rdev0->sb->md_minor);
                mddev = kdev_to_mddev(md_kdev);
                if (mddev) {
                        printk(KERN_WARNING "md: md%d already running, cannot run %s\n",
                               mdidx(mddev), partition_name(rdev0->dev));
                        ITERATE_RDEV_GENERIC(candidates,pending,rdev,tmp)
                                export_rdev(rdev);
                        continue;
                }
                mddev = alloc_mddev(md_kdev);
                if (!mddev) {
                        printk(KERN_ERR "md: cannot allocate memory for md drive.\n");
                        break;
                }
                if (md_kdev == countdev)
                        atomic_inc(&mddev->active);
                printk(KERN_INFO "md: created md%d\n", mdidx(mddev));
                ITERATE_RDEV_GENERIC(candidates,pending,rdev,tmp) {
                        bind_rdev_to_array(rdev, mddev);
                        md_list_del(&rdev->pending);
                        MD_INIT_LIST_HEAD(&rdev->pending);
                }
                autorun_array(mddev);
        }
        printk(KERN_INFO "md: ... autorun DONE.\n");
}
 
/*
 * import RAID devices based on one partition
 * if possible, the array gets run as well.
 */
 
#define BAD_VERSION KERN_ERR \
"md: %s has RAID superblock version 0.%d, autodetect needs v0.90 or higher\n"
 
#define OUT_OF_MEM KERN_ALERT \
"md: out of memory.\n"
 
#define NO_DEVICE KERN_ERR \
"md: disabled device %s\n"
 
#define AUTOADD_FAILED KERN_ERR \
"md: auto-adding devices to md%d FAILED (error %d).\n"
 
#define AUTOADD_FAILED_USED KERN_ERR \
"md: cannot auto-add device %s to md%d, already used.\n"
 
#define AUTORUN_FAILED KERN_ERR \
"md: auto-running md%d FAILED (error %d).\n"
 
#define MDDEV_BUSY KERN_ERR \
"md: cannot auto-add to md%d, already running.\n"
 
#define AUTOADDING KERN_INFO \
"md: auto-adding devices to md%d, based on %s's superblock.\n"
 
#define AUTORUNNING KERN_INFO \
"md: auto-running md%d.\n"
 
static int autostart_array(kdev_t startdev, kdev_t countdev)
{
        int err = -EINVAL, i;
        mdp_super_t *sb = NULL;
        mdk_rdev_t *start_rdev = NULL, *rdev;
 
        if (md_import_device(startdev, 1)) {
                printk(KERN_WARNING "md: could not import %s!\n", partition_name(startdev));
                goto abort;
        }
 
        start_rdev = find_rdev_all(startdev);
        if (!start_rdev) {
                MD_BUG();
                goto abort;
        }
        if (start_rdev->faulty) {
                printk(KERN_WARNING "md: can not autostart based on faulty %s!\n",
                                                partition_name(startdev));
                goto abort;
        }
        md_list_add(&start_rdev->pending, &pending_raid_disks);
 
        sb = start_rdev->sb;
 
        err = detect_old_array(sb);
        if (err) {
                printk(KERN_WARNING "md: array version is too old to be autostarted ,"
                       "use raidtools 0.90 mkraid --upgrade to upgrade the array "
                       "without data loss!\n");
                goto abort;
        }
 
        for (i = 0; i < MD_SB_DISKS; i++) {
                mdp_disk_t *desc;
                kdev_t dev;
 
                desc = sb->disks + i;
                dev = MKDEV(desc->major, desc->minor);
 
                if (dev == MKDEV(0,0))
                        continue;
                if (dev == startdev)
                        continue;
                if (md_import_device(dev, 1)) {
                        printk(KERN_WARNING "md: could not import %s, trying to run array nevertheless.\n",
                               partition_name(dev));
                        continue;
                }
                rdev = find_rdev_all(dev);
                if (!rdev) {
                        MD_BUG();
                        goto abort;
                }
                md_list_add(&rdev->pending, &pending_raid_disks);
        }
 
        /*
         * possibly return codes
         */
        autorun_devices(countdev);
        return 0;
 
abort:
        if (start_rdev)
                export_rdev(start_rdev);
        return err;
}
 
#undef BAD_VERSION
#undef OUT_OF_MEM
#undef NO_DEVICE
#undef AUTOADD_FAILED_USED
#undef AUTOADD_FAILED
#undef AUTORUN_FAILED
#undef AUTOADDING
#undef AUTORUNNING
 
 
static int get_version(void * arg)
{
        mdu_version_t ver;
 
        ver.major = MD_MAJOR_VERSION;
        ver.minor = MD_MINOR_VERSION;
        ver.patchlevel = MD_PATCHLEVEL_VERSION;
 
        if (md_copy_to_user(arg, &ver, sizeof(ver)))
                return -EFAULT;
 
        return 0;
}
 
#define SET_FROM_SB(x) info.x = mddev->sb->x
static int get_array_info(mddev_t * mddev, void * arg)
{
        mdu_array_info_t info;
 
        if (!mddev->sb) {
                MD_BUG();
                return -EINVAL;
        }
 
        SET_FROM_SB(major_version);
        SET_FROM_SB(minor_version);
        SET_FROM_SB(patch_version);
        SET_FROM_SB(ctime);
        SET_FROM_SB(level);
        SET_FROM_SB(size);
        SET_FROM_SB(nr_disks);
        SET_FROM_SB(raid_disks);
        SET_FROM_SB(md_minor);
        SET_FROM_SB(not_persistent);
 
        SET_FROM_SB(utime);
        SET_FROM_SB(state);
        SET_FROM_SB(active_disks);
        SET_FROM_SB(working_disks);
        SET_FROM_SB(failed_disks);
        SET_FROM_SB(spare_disks);
 
        SET_FROM_SB(layout);
        SET_FROM_SB(chunk_size);
 
        if (md_copy_to_user(arg, &info, sizeof(info)))
                return -EFAULT;
 
        return 0;
}
#undef SET_FROM_SB
 
#define SET_FROM_SB(x) info.x = mddev->sb->disks[nr].x
static int get_disk_info(mddev_t * mddev, void * arg)
{
        mdu_disk_info_t info;
        unsigned int nr;
 
        if (!mddev->sb)
                return -EINVAL;
 
        if (md_copy_from_user(&info, arg, sizeof(info)))
                return -EFAULT;
 
        nr = info.number;
        if (nr >= MD_SB_DISKS)
                return -EINVAL;
 
        SET_FROM_SB(major);
        SET_FROM_SB(minor);
        SET_FROM_SB(raid_disk);
        SET_FROM_SB(state);
 
        if (md_copy_to_user(arg, &info, sizeof(info)))
                return -EFAULT;
 
        return 0;
}
#undef SET_FROM_SB
 
#define SET_SB(x) mddev->sb->disks[nr].x = info->x
 
static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
{
        int err, size, persistent;
        mdk_rdev_t *rdev;
        unsigned int nr;
        kdev_t dev;
        dev = MKDEV(info->major,info->minor);
 
        if (find_rdev_all(dev)) {
                printk(KERN_WARNING "md: device %s already used in a RAID array!\n",
                       partition_name(dev));
                return -EBUSY;
        }
        if (!mddev->sb) {
                /* expecting a device which has a superblock */
                err = md_import_device(dev, 1);
                if (err) {
                        printk(KERN_WARNING "md: md_import_device returned %d\n", err);
                        return -EINVAL;
                }
                rdev = find_rdev_all(dev);
                if (!rdev) {
                        MD_BUG();
                        return -EINVAL;
                }
                if (mddev->nb_dev) {
                        mdk_rdev_t *rdev0 = md_list_entry(mddev->disks.next,
                                                        mdk_rdev_t, same_set);
                        if (!uuid_equal(rdev0, rdev)) {
                                printk(KERN_WARNING "md: %s has different UUID to %s\n",
                                       partition_name(rdev->dev), partition_name(rdev0->dev));
                                export_rdev(rdev);
                                return -EINVAL;
                        }
                        if (!sb_equal(rdev0->sb, rdev->sb)) {
                                printk(KERN_WARNING "md: %s has same UUID but different superblock to %s\n",
                                       partition_name(rdev->dev), partition_name(rdev0->dev));
                                export_rdev(rdev);
                                return -EINVAL;
                        }
                }
                bind_rdev_to_array(rdev, mddev);
                return 0;
        }
 
        nr = info->number;
        if (nr >= mddev->sb->nr_disks) {
                MD_BUG();
                return -EINVAL;
        }
 
 
        SET_SB(number);
        SET_SB(major);
        SET_SB(minor);
        SET_SB(raid_disk);
        SET_SB(state);
 
        if ((info->state & (1<<MD_DISK_FAULTY))==0) {
                err = md_import_device (dev, 0);
                if (err) {
                        printk(KERN_WARNING "md: error, md_import_device() returned %d\n", err);
                        return -EINVAL;
                }
                rdev = find_rdev_all(dev);
                if (!rdev) {
                        MD_BUG();
                        return -EINVAL;
                }
 
                rdev->old_dev = dev;
                rdev->desc_nr = info->number;
 
                bind_rdev_to_array(rdev, mddev);
 
                persistent = !mddev->sb->not_persistent;
                if (!persistent)
                        printk(KERN_INFO "md: nonpersistent superblock ...\n");
 
                size = calc_dev_size(dev, mddev, persistent);
                rdev->sb_offset = calc_dev_sboffset(dev, mddev, persistent);
 
                if (!mddev->sb->size || (mddev->sb->size > size))
                        mddev->sb->size = size;
        }
 
        /*
         * sync all other superblocks with the main superblock
         */
        sync_sbs(mddev);
 
        return 0;
}
#undef SET_SB
 
static int hot_generate_error(mddev_t * mddev, kdev_t dev)
{
        struct request_queue *q;
        mdk_rdev_t *rdev;
        mdp_disk_t *disk;
 
        if (!mddev->pers)
                return -ENODEV;
 
        printk(KERN_INFO "md: trying to generate %s error in md%d ... \n",
                partition_name(dev), mdidx(mddev));
 
        rdev = find_rdev(mddev, dev);
        if (!rdev) {
                MD_BUG();
                return -ENXIO;
        }
 
        if (rdev->desc_nr == -1) {
                MD_BUG();
                return -EINVAL;
        }
        disk = &mddev->sb->disks[rdev->desc_nr];
        if (!disk_active(disk))
                return -ENODEV;
 
        q = blk_get_queue(rdev->dev);
        if (!q) {
                MD_BUG();
                return -ENODEV;
        }
        printk(KERN_INFO "md: okay, generating error!\n");
//      q->oneshot_error = 1; // disabled for now
 
        return 0;
}
 
static int hot_remove_disk(mddev_t * mddev, kdev_t dev)
{
        int err;
        mdk_rdev_t *rdev;
        mdp_disk_t *disk;
 
        if (!mddev->pers)
                return -ENODEV;
 
        printk(KERN_INFO "md: trying to remove %s from md%d ... \n",
                partition_name(dev), mdidx(mddev));
 
        if (!mddev->pers->diskop) {
                printk(KERN_WARNING "md%d: personality does not support diskops!\n",
                       mdidx(mddev));
                return -EINVAL;
        }
 
        rdev = find_rdev(mddev, dev);
        if (!rdev)
                return -ENXIO;
 
        if (rdev->desc_nr == -1) {
                MD_BUG();
                return -EINVAL;
        }
        disk = &mddev->sb->disks[rdev->desc_nr];
        if (disk_active(disk))
                goto busy;
 
        if (disk_removed(disk))
                return -EINVAL;
 
        err = mddev->pers->diskop(mddev, &disk, DISKOP_HOT_REMOVE_DISK);
        if (err == -EBUSY)
                goto busy;
 
        if (err) {
                MD_BUG();
                return -EINVAL;
        }
 
        remove_descriptor(disk, mddev->sb);
        kick_rdev_from_array(rdev);
        mddev->sb_dirty = 1;
        md_update_sb(mddev);
 
        return 0;
busy:
        printk(KERN_WARNING "md: cannot remove active disk %s from md%d ... \n",
                partition_name(dev), mdidx(mddev));
        return -EBUSY;
}
 
static int hot_add_disk(mddev_t * mddev, kdev_t dev)
{
        int i, err, persistent;
        unsigned int size;
        mdk_rdev_t *rdev;
        mdp_disk_t *disk;
 
        if (!mddev->pers)
                return -ENODEV;
 
        printk(KERN_INFO "md: trying to hot-add %s to md%d ... \n",
                partition_name(dev), mdidx(mddev));
 
        if (!mddev->pers->diskop) {
                printk(KERN_WARNING "md%d: personality does not support diskops!\n",
                       mdidx(mddev));
                return -EINVAL;
        }
 
        persistent = !mddev->sb->not_persistent;
 
        rdev = find_rdev(mddev, dev);
        if (rdev)
                return -EBUSY;
 
        err = md_import_device (dev, 0);
        if (err) {
                printk(KERN_WARNING "md: error, md_import_device() returned %d\n", err);
                return -EINVAL;
        }
        rdev = find_rdev_all(dev);
        if (!rdev) {
                MD_BUG();
                return -EINVAL;
        }
        if (rdev->faulty) {
                printk(KERN_WARNING "md: can not hot-add faulty %s disk to md%d!\n",
                                partition_name(dev), mdidx(mddev));
                err = -EINVAL;
                goto abort_export;
        }
        size = calc_dev_size(dev, mddev, persistent);
 
        if (size < mddev->sb->size) {
                printk(KERN_WARNING "md%d: disk size %d blocks < array size %d\n",
                                mdidx(mddev), size, mddev->sb->size);
                err = -ENOSPC;
                goto abort_export;
        }
        bind_rdev_to_array(rdev, mddev);
 
        /*
         * The rest should better be atomic, we can have disk failures
         * noticed in interrupt contexts ...
         */
        rdev->old_dev = dev;
        rdev->size = size;
        rdev->sb_offset = calc_dev_sboffset(dev, mddev, persistent);
 
        disk = mddev->sb->disks + mddev->sb->raid_disks;
        for (i = mddev->sb->raid_disks; i < MD_SB_DISKS; i++) {
                disk = mddev->sb->disks + i;
 
                if (!disk->major && !disk->minor)
                        break;
                if (disk_removed(disk))
                        break;
        }
        if (i == MD_SB_DISKS) {
                printk(KERN_WARNING "md%d: can not hot-add to full array!\n",
                       mdidx(mddev));
                err = -EBUSY;
                goto abort_unbind_export;
        }
 
        if (disk_removed(disk)) {
                /*
                 * reuse slot
                 */
                if (disk->number != i) {
                        MD_BUG();
                        err = -EINVAL;
                        goto abort_unbind_export;
                }
        } else {
                disk->number = i;
        }
 
        disk->raid_disk = disk->number;
        disk->major = MAJOR(dev);
        disk->minor = MINOR(dev);
 
        if (mddev->pers->diskop(mddev, &disk, DISKOP_HOT_ADD_DISK)) {
                MD_BUG();
                err = -EINVAL;
                goto abort_unbind_export;
        }
 
        mark_disk_spare(disk);
        mddev->sb->nr_disks++;
        mddev->sb->spare_disks++;
        mddev->sb->working_disks++;
 
        mddev->sb_dirty = 1;
        md_update_sb(mddev);
 
        /*
         * Kick recovery, maybe this spare has to be added to the
         * array immediately.
         */
        md_recover_arrays();
 
        return 0;
 
abort_unbind_export:
        unbind_rdev_from_array(rdev);
 
abort_export:
        export_rdev(rdev);
        return err;
}
 
#define SET_SB(x) mddev->sb->x = info->x
static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
{
 
        if (alloc_array_sb(mddev))
                return -ENOMEM;
 
        mddev->sb->major_version = MD_MAJOR_VERSION;
        mddev->sb->minor_version = MD_MINOR_VERSION;
        mddev->sb->patch_version = MD_PATCHLEVEL_VERSION;
        mddev->sb->ctime = CURRENT_TIME;
 
        SET_SB(level);
        SET_SB(size);
        SET_SB(nr_disks);
        SET_SB(raid_disks);
        SET_SB(md_minor);
        SET_SB(not_persistent);
 
        SET_SB(state);
        SET_SB(active_disks);
        SET_SB(working_disks);
        SET_SB(failed_disks);
        SET_SB(spare_disks);
 
        SET_SB(layout);
        SET_SB(chunk_size);
 
        mddev->sb->md_magic = MD_SB_MAGIC;
 
        /*
         * Generate a 128 bit UUID
         */
        get_random_bytes(&mddev->sb->set_uuid0, 4);
        get_random_bytes(&mddev->sb->set_uuid1, 4);
        get_random_bytes(&mddev->sb->set_uuid2, 4);
        get_random_bytes(&mddev->sb->set_uuid3, 4);
 
        return 0;
}
#undef SET_SB
 
static int set_disk_info(mddev_t * mddev, void * arg)
{
        printk(KERN_INFO "md: not yet");
        return -EINVAL;
}
 
static int clear_array(mddev_t * mddev)
{
        printk(KERN_INFO "md: not yet");
        return -EINVAL;
}
 
static int write_raid_info(mddev_t * mddev)
{
        printk(KERN_INFO "md: not yet");
        return -EINVAL;
}
 
static int protect_array(mddev_t * mddev)
{
        printk(KERN_INFO "md: not yet");
        return -EINVAL;
}
 
static int unprotect_array(mddev_t * mddev)
{
        printk(KERN_INFO "md: not yet");
        return -EINVAL;
}
 
static int set_disk_faulty(mddev_t *mddev, kdev_t dev)
{
        int ret;
 
        ret = md_error(mddev, dev);
        return ret;
}
 
static int md_ioctl(struct inode *inode, struct file *file,
                        unsigned int cmd, unsigned long arg)
{
        unsigned int minor;
        int err = 0;
        struct hd_geometry *loc = (struct hd_geometry *) arg;
        mddev_t *mddev = NULL;
        kdev_t dev;
 
        if (!md_capable_admin())
                return -EACCES;
 
        dev = inode->i_rdev;
        minor = MINOR(dev);
        if (minor >= MAX_MD_DEVS) {
                MD_BUG();
                return -EINVAL;
        }
 
        /*
         * Commands dealing with the RAID driver but not any
         * particular array:
         */
        switch (cmd)
        {
                case RAID_VERSION:
                        err = get_version((void *)arg);
                        goto done;
 
                case PRINT_RAID_DEBUG:
                        err = 0;
                        md_print_devices();
                        goto done_unlock;
 
#ifndef MODULE
                case RAID_AUTORUN:
                        err = 0;
                        autostart_arrays();
                        goto done;
#endif
 
                case BLKGETSIZE:
                case BLKGETSIZE64:
                case BLKRAGET:
                case BLKRASET:
                case BLKFLSBUF:
                case BLKSSZGET:
                case BLKBSZGET:
                case BLKBSZSET:
                        err = blk_ioctl (dev, cmd, arg);
                        goto abort;
 
                default:;
        }
 
        /*
         * Commands creating/starting a new array:
         */
 
        mddev = kdev_to_mddev(dev);
 
        switch (cmd)
        {
                case SET_ARRAY_INFO:
                case START_ARRAY:
                        if (mddev) {
                                printk(KERN_WARNING "md: array md%d already exists!\n",
                                                                mdidx(mddev));
                                err = -EEXIST;
                                goto abort;
                        }
                default:;
        }
        switch (cmd)
        {
                case SET_ARRAY_INFO:
                        mddev = alloc_mddev(dev);
                        if (!mddev) {
                                err = -ENOMEM;
                                goto abort;
                        }
                        atomic_inc(&mddev->active);
 
                        /*
                         * alloc_mddev() should possibly self-lock.
                         */
                        err = lock_mddev(mddev);
                        if (err) {
                                printk(KERN_WARNING "md: ioctl, reason %d, cmd %d\n",
                                       err, cmd);
                                goto abort;
                        }
 
                        if (mddev->sb) {
                                printk(KERN_WARNING "md: array md%d already has a superblock!\n",
                                        mdidx(mddev));
                                err = -EBUSY;
                                goto abort_unlock;
                        }
                        if (arg) {
                                mdu_array_info_t info;
                                if (md_copy_from_user(&info, (void*)arg, sizeof(info))) {
                                        err = -EFAULT;
                                        goto abort_unlock;
                                }
                                err = set_array_info(mddev, &info);
                                if (err) {
                                        printk(KERN_WARNING "md: couldnt set array info. %d\n", err);
                                        goto abort_unlock;
                                }
                        }
                        goto done_unlock;
 
                case START_ARRAY:
                        /*
                         * possibly make it lock the array ...
                         */
                        err = autostart_array((kdev_t)arg, dev);
                        if (err) {
                                printk(KERN_WARNING "md: autostart %s failed!\n",
                                        partition_name((kdev_t)arg));
                                goto abort;
                        }
                        goto done;
 
                default:;
        }
 
        /*
         * Commands querying/configuring an existing array:
         */
 
        if (!mddev) {
                err = -ENODEV;
                goto abort;
        }
        err = lock_mddev(mddev);
        if (err) {
                printk(KERN_INFO "md: ioctl lock interrupted, reason %d, cmd %d\n",err, cmd);
                goto abort;
        }
        /* if we don't have a superblock yet, only ADD_NEW_DISK or STOP_ARRAY is allowed */
        if (!mddev->sb && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY && cmd != RUN_ARRAY) {
                err = -ENODEV;
                goto abort_unlock;
        }
 
        /*
         * Commands even a read-only array can execute:
         */
        switch (cmd)
        {
                case GET_ARRAY_INFO:
                        err = get_array_info(mddev, (void *)arg);
                        goto done_unlock;
 
                case GET_DISK_INFO:
                        err = get_disk_info(mddev, (void *)arg);
                        goto done_unlock;
 
                case RESTART_ARRAY_RW:
                        err = restart_array(mddev);
                        goto done_unlock;
 
                case STOP_ARRAY:
                        if (inode->i_bdev->bd_openers > 1)
                                err = -EBUSY;
                        else if (!(err = do_md_stop (mddev, 0)))
                                mddev = NULL;
                        goto done_unlock;
 
                case STOP_ARRAY_RO:
                        if (inode->i_bdev->bd_openers > 1)
                                err = -EBUSY;
                        else
                                err = do_md_stop (mddev, 1);
                        goto done_unlock;
 
        /*
         * We have a problem here : there is no easy way to give a CHS
         * virtual geometry. We currently pretend that we have a 2 heads
         * 4 sectors (with a BIG number of cylinders...). This drives
         * dosfs just mad... ;-)
         */
                case HDIO_GETGEO:
                        if (!loc) {
                                err = -EINVAL;
                                goto abort_unlock;
                        }
                        err = md_put_user (2, (char *) &loc->heads);
                        if (err)
                                goto abort_unlock;
                        err = md_put_user (4, (char *) &loc->sectors);
                        if (err)
                                goto abort_unlock;
                        err = md_put_user (md_hd_struct[mdidx(mddev)].nr_sects/8,
                                                (short *) &loc->cylinders);
                        if (err)
                                goto abort_unlock;
                        err = md_put_user (md_hd_struct[minor].start_sect,
                                                (long *) &loc->start);
                        goto done_unlock;
        }
 
        /*
         * The remaining ioctls are changing the state of the
         * superblock, so we do not allow read-only arrays
         * here:
         */
        if (mddev->ro) {
                err = -EROFS;
                goto abort_unlock;
        }
 
        switch (cmd)
        {
                case CLEAR_ARRAY:
                        err = clear_array(mddev);
                        goto done_unlock;
 
                case ADD_NEW_DISK:
                {
                        mdu_disk_info_t info;
                        if (md_copy_from_user(&info, (void*)arg, sizeof(info)))
                                err = -EFAULT;
                        else
                                err = add_new_disk(mddev, &info);
                        goto done_unlock;
                }
                case HOT_GENERATE_ERROR:
                        err = hot_generate_error(mddev, (kdev_t)arg);
                        goto done_unlock;
                case HOT_REMOVE_DISK:
                        err = hot_remove_disk(mddev, (kdev_t)arg);
                        goto done_unlock;
 
                case HOT_ADD_DISK:
                        err = hot_add_disk(mddev, (kdev_t)arg);
                        goto done_unlock;
 
                case SET_DISK_INFO:
                        err = set_disk_info(mddev, (void *)arg);
                        goto done_unlock;
 
                case WRITE_RAID_INFO:
                        err = write_raid_info(mddev);
                        goto done_unlock;
 
                case UNPROTECT_ARRAY:
                        err = unprotect_array(mddev);
                        goto done_unlock;
 
                case PROTECT_ARRAY:
                        err = protect_array(mddev);
                        goto done_unlock;
 
                case SET_DISK_FAULTY:
                        err = set_disk_faulty(mddev, (kdev_t)arg);
                        goto done_unlock;
 
                case RUN_ARRAY:
                {
/* The data is never used....
                        mdu_param_t param;
                        err = md_copy_from_user(&param, (mdu_param_t *)arg,
                                                         sizeof(param));
                        if (err)
                                goto abort_unlock;
*/
                        err = do_md_run (mddev);
                        /*
                         * we have to clean up the mess if
                         * the array cannot be run for some
                         * reason ...
                         */
                        if (err) {
                                mddev->sb_dirty = 0;
                                if (!do_md_stop (mddev, 0))
                                        mddev = NULL;
                        }
                        goto done_unlock;
                }
 
                default:
                        printk(KERN_WARNING "md: %s(pid %d) used obsolete MD ioctl, "
                               "upgrade your software to use new ictls.\n",
                               current->comm, current->pid);
                        err = -EINVAL;
                        goto abort_unlock;
        }
 
done_unlock:
abort_unlock:
        if (mddev)
                unlock_mddev(mddev);
 
        return err;
done:
        if (err)
                MD_BUG();
abort:
        return err;
}
 
static int md_open(struct inode *inode, struct file *file)
{
        /*
         * Always succeed, but increment the usage count
         */
        mddev_t *mddev = kdev_to_mddev(inode->i_rdev);
        if (mddev)
                atomic_inc(&mddev->active);
        return (0);
}
 
static int md_release(struct inode *inode, struct file * file)
{
        mddev_t *mddev = kdev_to_mddev(inode->i_rdev);
        if (mddev)
                atomic_dec(&mddev->active);
        return 0;
}
 
static struct block_device_operations md_fops=
{
        owner:          THIS_MODULE,
        open:           md_open,
        release:        md_release,
        ioctl:          md_ioctl,
};
 
 
int md_thread(void * arg)
{
        mdk_thread_t *thread = arg;
 
        md_lock_kernel();
 
        /*
         * Detach thread
         */
 
        daemonize();
 
        sprintf(current->comm, thread->name);
        md_init_signals();
        md_flush_signals();
        thread->tsk = current;
 
        /*
         * md_thread is a 'system-thread', it's priority should be very
         * high. We avoid resource deadlocks individually in each
         * raid personality. (RAID5 does preallocation) We also use RR and
         * the very same RT priority as kswapd, thus we will never get
         * into a priority inversion deadlock.
         *
         * we definitely have to have equal or higher priority than
         * bdflush, otherwise bdflush will deadlock if there are too
         * many dirty RAID5 blocks.
         */
        current->policy = SCHED_OTHER;
        current->nice = -20;
        md_unlock_kernel();
 
        complete(thread->event);
        while (thread->run) {
                void (*run)(void *data);
                DECLARE_WAITQUEUE(wait, current);
 
                add_wait_queue(&thread->wqueue, &wait);
                set_task_state(current, TASK_INTERRUPTIBLE);
                if (!test_bit(THREAD_WAKEUP, &thread->flags)) {
                        dprintk("md: thread %p went to sleep.\n", thread);
                        schedule();
                        dprintk("md: thread %p woke up.\n", thread);
                }
                current->state = TASK_RUNNING;
                remove_wait_queue(&thread->wqueue, &wait);
                clear_bit(THREAD_WAKEUP, &thread->flags);
 
                run = thread->run;
                if (run) {
                        run(thread->data);
                        run_task_queue(&tq_disk);
                }
                if (md_signal_pending(current))
                        md_flush_signals();
        }
        complete(thread->event);
        return 0;
}
 
void md_wakeup_thread(mdk_thread_t *thread)
{
        dprintk("md: waking up MD thread %p.\n", thread);
        set_bit(THREAD_WAKEUP, &thread->flags);
        wake_up(&thread->wqueue);
}
 
mdk_thread_t *md_register_thread(void (*run) (void *),
                                                void *data, const char *name)
{
        mdk_thread_t *thread;
        int ret;
        struct completion event;
 
        thread = (mdk_thread_t *) kmalloc
                                (sizeof(mdk_thread_t), GFP_KERNEL);
        if (!thread)
                return NULL;
 
        memset(thread, 0, sizeof(mdk_thread_t));
        md_init_waitqueue_head(&thread->wqueue);
 
        init_completion(&event);
        thread->event = &event;
        thread->run = run;
        thread->data = data;
        thread->name = name;
        ret = kernel_thread(md_thread, thread, 0);
        if (ret < 0) {
                kfree(thread);
                return NULL;
        }
        wait_for_completion(&event);
        return thread;
}
 
void md_interrupt_thread(mdk_thread_t *thread)
{
        if (!thread->tsk) {
                MD_BUG();
                return;
        }
        dprintk("interrupting MD-thread pid %d\n", thread->tsk->pid);
        send_sig(SIGKILL, thread->tsk, 1);
}
 
void md_unregister_thread(mdk_thread_t *thread)
{
        struct completion event;
 
        init_completion(&event);
 
        thread->event = &event;
        thread->run = NULL;
        thread->name = NULL;
        md_interrupt_thread(thread);
        wait_for_completion(&event);
        kfree(thread);
}
 
void md_recover_arrays(void)
{
        if (!md_recovery_thread) {
                MD_BUG();
                return;
        }
        md_wakeup_thread(md_recovery_thread);
}
 
 
int md_error(mddev_t *mddev, kdev_t rdev)
{
        mdk_rdev_t * rrdev;
 
        dprintk("md_error dev:(%d:%d), rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
                MAJOR(dev),MINOR(dev),MAJOR(rdev),MINOR(rdev),
                __builtin_return_address(0),__builtin_return_address(1),
                __builtin_return_address(2),__builtin_return_address(3));
 
        if (!mddev) {
                MD_BUG();
                return 0;
        }
        rrdev = find_rdev(mddev, rdev);
        if (!rrdev || rrdev->faulty)
                return 0;
        if (!mddev->pers->error_handler
                        || mddev->pers->error_handler(mddev,rdev) <= 0) {
                rrdev->faulty = 1;
        } else
                return 1;
        /*
         * if recovery was running, stop it now.
         */
        if (mddev->pers->stop_resync)
                mddev->pers->stop_resync(mddev);
        if (mddev->recovery_running)
                md_interrupt_thread(md_recovery_thread);
        md_recover_arrays();
 
        return 0;
}
 
static void status_unused(struct seq_file *seq)
{
        int i = 0;
        mdk_rdev_t *rdev;
        struct md_list_head *tmp;
 
        seq_printf(seq, "unused devices: ");
 
        ITERATE_RDEV_ALL(rdev,tmp) {
                if (!rdev->same_set.next && !rdev->same_set.prev) {
                        /*
                         * The device is not yet used by any array.
                         */
                        i++;
                        seq_printf(seq, "%s ",
                                partition_name(rdev->dev));
                }
        }
        if (!i)
                seq_printf(seq, "<none>");
 
        seq_printf(seq, "\n");
}
 
 
static void status_resync(struct seq_file *seq, mddev_t * mddev)
{
        unsigned long max_blocks, resync, res, dt, db, rt;
 
        resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active))/2;
        max_blocks = mddev->sb->size;
 
        /*
         * Should not happen.
         */
        if (!max_blocks)
                MD_BUG();
 
        res = (resync/1024)*1000/(max_blocks/1024 + 1);
        {
                int i, x = res/50, y = 20-x;
                seq_printf(seq, "[");
                for (i = 0; i < x; i++)
                        seq_printf(seq, "=");
                seq_printf(seq, ">");
                for (i = 0; i < y; i++)
                        seq_printf(seq, ".");
                seq_printf(seq, "] ");
        }
        if (!mddev->recovery_running)
                /*
                 * true resync
                 */
                seq_printf(seq, " resync =%3lu.%lu%% (%lu/%lu)",
                                res/10, res % 10, resync, max_blocks);
        else
                /*
                 * recovery ...
                 */
                seq_printf(seq, " recovery =%3lu.%lu%% (%lu/%lu)",
                                res/10, res % 10, resync, max_blocks);
 
        /*
         * We do not want to overflow, so the order of operands and
         * the * 100 / 100 trick are important. We do a +1 to be
         * safe against division by zero. We only estimate anyway.
         *
         * dt: time from mark until now
         * db: blocks written from mark until now
         * rt: remaining time
         */
        dt = ((jiffies - mddev->resync_mark) / HZ);
        if (!dt) dt++;
        db = resync - (mddev->resync_mark_cnt/2);
        rt = (dt * ((max_blocks-resync) / (db/100+1)))/100;
 
        seq_printf(seq, " finish=%lu.%lumin", rt / 60, (rt % 60)/6);
 
        seq_printf(seq, " speed=%ldK/sec", db/dt);
 
}
 
 
static void *md_seq_start(struct seq_file *seq, loff_t *pos)
{
        struct list_head *tmp;
        loff_t l = *pos;
        mddev_t *mddev;
 
        if (l >= 0x10000)
                return NULL;
        if (!l--)
                /* header */
                return (void*)1;
 
        list_for_each(tmp,&all_mddevs)
                if (!l--) {
                        mddev = list_entry(tmp, mddev_t, all_mddevs);
                        return mddev;
                }
        if (!l--)
                return (void*)2;/* tail */
        return NULL;
}
 
static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
        struct list_head *tmp;
        mddev_t *next_mddev, *mddev = v;
 
        ++*pos;
        if (v == (void*)2)
                return NULL;
 
        if (v == (void*)1)
                tmp = all_mddevs.next;
        else
                tmp = mddev->all_mddevs.next;
        if (tmp != &all_mddevs)
                next_mddev = list_entry(tmp,mddev_t,all_mddevs);
        else {
                next_mddev = (void*)2;
                *pos = 0x10000;
        }
 
        return next_mddev;
 
}
 
static void md_seq_stop(struct seq_file *seq, void *v)
{
 
}
 
static int md_seq_show(struct seq_file *seq, void *v)
{
        int j, size;
        struct md_list_head *tmp2;
        mdk_rdev_t *rdev;
        mddev_t *mddev = v;
 
        if (v == (void*)1) {
                seq_printf(seq, "Personalities : ");
                for (j = 0; j < MAX_PERSONALITY; j++)
                        if (pers[j])
                                seq_printf(seq, "[%s] ", pers[j]->name);
 
                seq_printf(seq, "\n");
                seq_printf(seq, "read_ahead ");
                if (read_ahead[MD_MAJOR] == INT_MAX)
                        seq_printf(seq, "not set\n");
                else
                        seq_printf(seq, "%d sectors\n", read_ahead[MD_MAJOR]);
                return 0;
        }
        if (v == (void*)2) {
                status_unused(seq);
                return 0;
        }
 
        seq_printf(seq, "md%d : %sactive", mdidx(mddev),
                   mddev->pers ? "" : "in");
        if (mddev->pers) {
                if (mddev->ro)
                        seq_printf(seq, " (read-only)");
                seq_printf(seq, " %s", mddev->pers->name);
        }
 
        size = 0;
        ITERATE_RDEV(mddev,rdev,tmp2) {
                seq_printf(seq, " %s[%d]",
                           partition_name(rdev->dev), rdev->desc_nr);
                if (rdev->faulty) {
                        seq_printf(seq, "(F)");
                        continue;
                }
                size += rdev->size;
        }
 
        if (mddev->nb_dev) {
                if (mddev->pers)
                        seq_printf(seq, "\n      %d blocks",
                                   md_size[mdidx(mddev)]);
                else
                        seq_printf(seq, "\n      %d blocks", size);
        }
 
        if (mddev->pers) {
 
                mddev->pers->status (seq, mddev);
 
                seq_printf(seq, "\n      ");
                if (mddev->curr_resync) {
                        status_resync (seq, mddev);
                } else {
                        if (sem_getcount(&mddev->resync_sem) != 1)
                                seq_printf(seq, "       resync=DELAYED");
                }
        }
        seq_printf(seq, "\n");
 
        return 0;
}
 
 
static struct seq_operations md_seq_ops = {
        .start  = md_seq_start,
        .next   = md_seq_next,
        .stop   = md_seq_stop,
        .show   = md_seq_show,
};
 
static int md_seq_open(struct inode *inode, struct file *file)
{
        int error;
 
        error = seq_open(file, &md_seq_ops);
        return error;
}
 
static struct file_operations md_seq_fops = {
        .open           = md_seq_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
};
 
 
int register_md_personality(int pnum, mdk_personality_t *p)
{
        if (pnum >= MAX_PERSONALITY) {
                MD_BUG();
                return -EINVAL;
        }
 
        if (pers[pnum]) {
                MD_BUG();
                return -EBUSY;
        }
 
        pers[pnum] = p;
        printk(KERN_INFO "md: %s personality registered as nr %d\n", p->name, pnum);
        return 0;
}
 
int unregister_md_personality(int pnum)
{
        if (pnum >= MAX_PERSONALITY) {
                MD_BUG();
                return -EINVAL;
        }
 
        printk(KERN_INFO "md: %s personality unregistered\n", pers[pnum]->name);
        pers[pnum] = NULL;
        return 0;
}
 
mdp_disk_t *get_spare(mddev_t *mddev)
{
        mdp_super_t *sb = mddev->sb;
        mdp_disk_t *disk;
        mdk_rdev_t *rdev;
        struct md_list_head *tmp;
 
        ITERATE_RDEV(mddev,rdev,tmp) {
                if (rdev->faulty)
                        continue;
                if (!rdev->sb) {
                        MD_BUG();
                        continue;
                }
                disk = &sb->disks[rdev->desc_nr];
                if (disk_faulty(disk)) {
                        MD_BUG();
                        continue;
                }
                if (disk_active(disk))
                        continue;
                return disk;
        }
        return NULL;
}
 
static unsigned int sync_io[DK_MAX_MAJOR][DK_MAX_DISK];
void md_sync_acct(kdev_t dev, unsigned long nr_sectors)
{
        unsigned int major = MAJOR(dev);
        unsigned int index;
 
        index = disk_index(dev);
        if ((index >= DK_MAX_DISK) || (major >= DK_MAX_MAJOR))
                return;
 
        sync_io[major][index] += nr_sectors;
}
 
static int is_mddev_idle(mddev_t *mddev)
{
        mdk_rdev_t * rdev;
        struct md_list_head *tmp;
        int idle;
        unsigned long curr_events;
 
        idle = 1;
        ITERATE_RDEV(mddev,rdev,tmp) {
                int major = MAJOR(rdev->dev);
                int idx = disk_index(rdev->dev);
 
                if ((idx >= DK_MAX_DISK) || (major >= DK_MAX_MAJOR))
                        continue;
 
                curr_events = kstat.dk_drive_rblk[major][idx] +
                                                kstat.dk_drive_wblk[major][idx] ;
                curr_events -= sync_io[major][idx];
                if ((curr_events - rdev->last_events) > 32) {
                        rdev->last_events = curr_events;
                        idle = 0;
                }
        }
        return idle;
}
 
MD_DECLARE_WAIT_QUEUE_HEAD(resync_wait);
 
void md_done_sync(mddev_t *mddev, int blocks, int ok)
{
        /* another "blocks" (512byte) blocks have been synced */
        atomic_sub(blocks, &mddev->recovery_active);
        wake_up(&mddev->recovery_wait);
        if (!ok) {
                // stop recovery, signal do_sync ....
                if (mddev->pers->stop_resync)
                        mddev->pers->stop_resync(mddev);
                if (mddev->recovery_running)
                        md_interrupt_thread(md_recovery_thread);
        }
}
 
#define SYNC_MARKS      10
#define SYNC_MARK_STEP  (3*HZ)
int md_do_sync(mddev_t *mddev, mdp_disk_t *spare)
{
        mddev_t *mddev2;
        unsigned int max_sectors, currspeed,
                j, window, err, serialize;
        unsigned long mark[SYNC_MARKS];
        unsigned long mark_cnt[SYNC_MARKS];
        int last_mark,m;
        struct md_list_head *tmp;
        unsigned long last_check;
 
 
        err = down_interruptible(&mddev->resync_sem);
        if (err)
                goto out_nolock;
 
recheck:
        serialize = 0;
        ITERATE_MDDEV(mddev2,tmp) {
                if (mddev2 == mddev)
                        continue;
                if (mddev2->curr_resync && match_mddev_units(mddev,mddev2)) {
                        printk(KERN_INFO "md: delaying resync of md%d until md%d "
                               "has finished resync (they share one or more physical units)\n",
                               mdidx(mddev), mdidx(mddev2));
                        serialize = 1;
                        break;
                }
        }
        if (serialize) {
                interruptible_sleep_on(&resync_wait);
                if (md_signal_pending(current)) {
                        md_flush_signals();
                        err = -EINTR;
                        goto out;
                }
                goto recheck;
        }
 
        mddev->curr_resync = 1;
 
        max_sectors = mddev->sb->size<<1;
 
        printk(KERN_INFO "md: syncing RAID array md%d\n", mdidx(mddev));
        printk(KERN_INFO "md: minimum _guaranteed_ reconstruction speed: %d KB/sec/disc.\n",
                                                sysctl_speed_limit_min);
        printk(KERN_INFO "md: using maximum available idle IO bandwith "
               "(but not more than %d KB/sec) for reconstruction.\n",
               sysctl_speed_limit_max);
 
        /*
         * Resync has low priority.
         */
        current->nice = 19;
 
        is_mddev_idle(mddev); /* this also initializes IO event counters */
        for (m = 0; m < SYNC_MARKS; m++) {
                mark[m] = jiffies;
                mark_cnt[m] = 0;
        }
        last_mark = 0;
        mddev->resync_mark = mark[last_mark];
        mddev->resync_mark_cnt = mark_cnt[last_mark];
 
        /*
         * Tune reconstruction:
         */
        window = vm_max_readahead*(PAGE_SIZE/512);
        printk(KERN_INFO "md: using %dk window, over a total of %d blocks.\n",
               window/2,max_sectors/2);
 
        atomic_set(&mddev->recovery_active, 0);
        init_waitqueue_head(&mddev->recovery_wait);
        last_check = 0;
        for (j = 0; j < max_sectors;) {
                int sectors;
 
                sectors = mddev->pers->sync_request(mddev, j);
 
                if (sectors < 0) {
                        err = sectors;
                        goto out;
                }
                atomic_add(sectors, &mddev->recovery_active);
                j += sectors;
                mddev->curr_resync = j;
 
                if (last_check + window > j)
                        continue;
 
                last_check = j;
 
                run_task_queue(&tq_disk);
 
        repeat:
                if (jiffies >= mark[last_mark] + SYNC_MARK_STEP ) {
                        /* step marks */
                        int next = (last_mark+1) % SYNC_MARKS;
 
                        mddev->resync_mark = mark[next];
                        mddev->resync_mark_cnt = mark_cnt[next];
                        mark[next] = jiffies;
                        mark_cnt[next] = j - atomic_read(&mddev->recovery_active);
                        last_mark = next;
                }
 
 
                if (md_signal_pending(current)) {
                        /*
                         * got a signal, exit.
                         */
                        mddev->curr_resync = 0;
                        printk(KERN_INFO "md: md_do_sync() got signal ... exiting\n");
                        md_flush_signals();
                        err = -EINTR;
                        goto out;
                }
 
                /*
                 * this loop exits only if either when we are slower than
                 * the 'hard' speed limit, or the system was IO-idle for
                 * a jiffy.
                 * the system might be non-idle CPU-wise, but we only care
                 * about not overloading the IO subsystem. (things like an
                 * e2fsck being done on the RAID array should execute fast)
                 */
                if (md_need_resched(current))
                        schedule();
 
                currspeed = (j-mddev->resync_mark_cnt)/2/((jiffies-mddev->resync_mark)/HZ +1) +1;
 
                if (currspeed > sysctl_speed_limit_min) {
                        current->nice = 19;
 
                        if ((currspeed > sysctl_speed_limit_max) ||
                                        !is_mddev_idle(mddev)) {
                                current->state = TASK_INTERRUPTIBLE;
                                md_schedule_timeout(HZ/4);
                                goto repeat;
                        }
                } else
                        current->nice = -20;
        }
        printk(KERN_INFO "md: md%d: sync done.\n",mdidx(mddev));
        err = 0;
        /*
         * this also signals 'finished resyncing' to md_stop
         */
out:
        wait_disk_event(mddev->recovery_wait, atomic_read(&mddev->recovery_active)==0);
        up(&mddev->resync_sem);
out_nolock:
        mddev->curr_resync = 0;
        wake_up(&resync_wait);
        return err;
}
 
 
/*
 * This is a kernel thread which syncs a spare disk with the active array
 *
 * the amount of foolproofing might seem to be a tad excessive, but an
 * early (not so error-safe) version of raid1syncd synced the first 0.5 gigs
 * of my root partition with the first 0.5 gigs of my /home partition ... so
 * i'm a bit nervous ;)
 */
void md_do_recovery(void *data)
{
        int err;
        mddev_t *mddev;
        mdp_super_t *sb;
        mdp_disk_t *spare;
        struct md_list_head *tmp;
 
        printk(KERN_INFO "md: recovery thread got woken up ...\n");
restart:
        ITERATE_MDDEV(mddev,tmp) {
                sb = mddev->sb;
                if (!sb)
                        continue;
                if (mddev->recovery_running)
                        continue;
                if (sb->active_disks == sb->raid_disks)
                        continue;
                if (mddev->sb_dirty)
                        md_update_sb(mddev);
                if (!sb->spare_disks) {
                        printk(KERN_ERR "md%d: no spare disk to reconstruct array! "
                               "-- continuing in degraded mode\n", mdidx(mddev));
                        continue;
                }
                /*
                 * now here we get the spare and resync it.
                 */
                spare = get_spare(mddev);
                if (!spare)
                        continue;
                printk(KERN_INFO "md%d: resyncing spare disk %s to replace failed disk\n",
                       mdidx(mddev), partition_name(MKDEV(spare->major,spare->minor)));
                if (!mddev->pers->diskop)
                        continue;
                if (mddev->pers->diskop(mddev, &spare, DISKOP_SPARE_WRITE))
                        continue;
                down(&mddev->recovery_sem);
                mddev->recovery_running = 1;
                err = md_do_sync(mddev, spare);
                if (err == -EIO) {
                        printk(KERN_INFO "md%d: spare disk %s failed, skipping to next spare.\n",
                               mdidx(mddev), partition_name(MKDEV(spare->major,spare->minor)));
                        if (!disk_faulty(spare)) {
                                mddev->pers->diskop(mddev,&spare,DISKOP_SPARE_INACTIVE);
                                mark_disk_faulty(spare);
                                mark_disk_nonsync(spare);
                                mark_disk_inactive(spare);
                                sb->spare_disks--;
                                sb->working_disks--;
                                sb->failed_disks++;
                        }
                } else
                        if (disk_faulty(spare))
                                mddev->pers->diskop(mddev, &spare,
                                                DISKOP_SPARE_INACTIVE);
                if (err == -EINTR || err == -ENOMEM) {
                        /*
                         * Recovery got interrupted, or ran out of mem ...
                         * signal back that we have finished using the array.
                         */
                        mddev->pers->diskop(mddev, &spare,
                                                         DISKOP_SPARE_INACTIVE);
                        up(&mddev->recovery_sem);
                        mddev->recovery_running = 0;
                        continue;
                } else {
                        mddev->recovery_running = 0;
                        up(&mddev->recovery_sem);
                }
                if (!disk_faulty(spare)) {
                        /*
                         * the SPARE_ACTIVE diskop possibly changes the
                         * pointer too
                         */
                        mddev->pers->diskop(mddev, &spare, DISKOP_SPARE_ACTIVE);
                        mark_disk_sync(spare);
                        mark_disk_active(spare);
                        sb->active_disks++;
                        sb->spare_disks--;
                }
                mddev->sb_dirty = 1;
                md_update_sb(mddev);
                goto restart;
        }
        printk(KERN_INFO "md: recovery thread finished ...\n");
 
}
 
int md_notify_reboot(struct notifier_block *this,
                                        unsigned long code, void *x)
{
        struct md_list_head *tmp;
        mddev_t *mddev;
 
        if ((code == MD_SYS_DOWN) || (code == MD_SYS_HALT)
                                        || (code == MD_SYS_POWER_OFF)) {
 
                printk(KERN_INFO "md: stopping all md devices.\n");
 
                ITERATE_MDDEV(mddev,tmp)
                        do_md_stop (mddev, 1);
                /*
                 * certain more exotic SCSI devices are known to be
                 * volatile wrt too early system reboots. While the
                 * right place to handle this issue is the given
                 * driver, we do want to have a safe RAID driver ...
                 */
                md_mdelay(1000*1);
        }
        return NOTIFY_DONE;
}
 
struct notifier_block md_notifier = {
        notifier_call:  md_notify_reboot,
        next:           NULL,
        priority:       INT_MAX, /* before any real devices */
};
 
static void md_geninit(void)
{
        struct proc_dir_entry *p;
        int i;
 
        for(i = 0; i < MAX_MD_DEVS; i++) {
                md_blocksizes[i] = 1024;
                md_size[i] = 0;
                md_hardsect_sizes[i] = 512;
                md_maxreadahead[i] = MD_READAHEAD;
        }
        blksize_size[MAJOR_NR] = md_blocksizes;
        blk_size[MAJOR_NR] = md_size;
        max_readahead[MAJOR_NR] = md_maxreadahead;
        hardsect_size[MAJOR_NR] = md_hardsect_sizes;
 
        dprintk("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
 
#ifdef CONFIG_PROC_FS
        p = create_proc_entry("mdstat", S_IRUGO, NULL);
        if (p)
                p->proc_fops = &md_seq_fops;
#endif
}
 
int md__init md_init(void)
{
        static char * name = "mdrecoveryd";
        int minor;
 
        printk(KERN_INFO "md: md driver %d.%d.%d MAX_MD_DEVS=%d, MD_SB_DISKS=%d\n",
                        MD_MAJOR_VERSION, MD_MINOR_VERSION,
                        MD_PATCHLEVEL_VERSION, MAX_MD_DEVS, MD_SB_DISKS);
 
        if (devfs_register_blkdev (MAJOR_NR, "md", &md_fops))
        {
                printk(KERN_ALERT "md: Unable to get major %d for md\n", MAJOR_NR);
                return (-1);
        }
        devfs_handle = devfs_mk_dir (NULL, "md", NULL);
        /* we don't use devfs_register_series because we want to fill md_hd_struct */
        for (minor=0; minor < MAX_MD_DEVS; ++minor) {
                char devname[128];
                sprintf (devname, "%u", minor);
                md_hd_struct[minor].de = devfs_register (devfs_handle,
                        devname, DEVFS_FL_DEFAULT, MAJOR_NR, minor,
                        S_IFBLK | S_IRUSR | S_IWUSR, &md_fops, NULL);
        }
 
        /* forward all md request to md_make_request */
        blk_queue_make_request(BLK_DEFAULT_QUEUE(MAJOR_NR), md_make_request);
 
 
        read_ahead[MAJOR_NR] = INT_MAX;
 
        add_gendisk(&md_gendisk);
 
        md_recovery_thread = md_register_thread(md_do_recovery, NULL, name);
        if (!md_recovery_thread)
                printk(KERN_ALERT "md: bug: couldn't allocate md_recovery_thread\n");
 
        md_register_reboot_notifier(&md_notifier);
        raid_table_header = register_sysctl_table(raid_root_table, 1);
 
        md_geninit();
        return (0);
}
 
 
#ifndef MODULE
 
/*
 * 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.
 */
 
struct {
        int set;
        int noautodetect;
} raid_setup_args md__initdata;
 
/*
 * Searches all registered partitions for autorun RAID arrays
 * at boot time.
 */
static kdev_t detected_devices[128];
static int dev_cnt;
 
void md_autodetect_dev(kdev_t dev)
{
        if (dev_cnt >= 0 && dev_cnt < 127)
                detected_devices[dev_cnt++] = dev;
}
 
 
static void autostart_arrays(void)
{
        mdk_rdev_t *rdev;
        int i;
 
        printk(KERN_INFO "md: Autodetecting RAID arrays.\n");
 
        for (i = 0; i < dev_cnt; i++) {
                kdev_t dev = detected_devices[i];
 
                if (md_import_device(dev,1)) {
                        printk(KERN_ALERT "md: could not import %s!\n",
                                partition_name(dev));
                        continue;
                }
                /*
                 * Sanity checks:
                 */
                rdev = find_rdev_all(dev);
                if (!rdev) {
                        MD_BUG();
                        continue;
                }
                if (rdev->faulty) {
                        MD_BUG();
                        continue;
                }
                md_list_add(&rdev->pending, &pending_raid_disks);
        }
        dev_cnt = 0;
 
        autorun_devices(-1);
}
 
static struct {
        char device_set [MAX_MD_DEVS];
        int pers[MAX_MD_DEVS];
        int chunk[MAX_MD_DEVS];
        char *device_names[MAX_MD_DEVS];
} md_setup_args md__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 persistant-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 md__init md_setup(char *str)
{
        int minor, level, factor, fault;
        char *pername = "";
        char *str1 = str;
 
        if (get_option(&str, &minor) != 2) {    /* MD Number */
                printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
                return 0;
        }
        if (minor >= MAX_MD_DEVS) {
                printk(KERN_WARNING "md: md=%d, Minor device number too high.\n", minor);
                return 0;
        } else if (md_setup_args.device_names[minor]) {
                printk(KERN_WARNING "md: md=%d, Specified more then once. "
                       "Replacing previous definition.\n", minor);
        }
        switch (get_option(&str, &level)) {     /* RAID Personality */
        case 2: /* could be 0 or -1.. */
                if (level == 0 || level == -1) {
                        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.pers[minor] = level;
                        md_setup_args.chunk[minor] = 1 << (factor+12);
                        switch(level) {
                        case -1:
                                level = LINEAR;
                                pername = "linear";
                                break;
                        case 0:
                                level = RAID0;
                                pername = "raid0";
                                break;
                        default:
                                printk(KERN_WARNING
                                       "md: The kernel has not been configured for raid%d support!\n",
                                       level);
                                return 0;
                        }
                        md_setup_args.pers[minor] = level;
                        break;
                }
                /* FALL THROUGH */
        case 1: /* the first device is numeric */
                str = str1;
                /* FALL THROUGH */
        case 0:
                md_setup_args.pers[minor] = 0;
                pername="super-block";
        }
 
        printk(KERN_INFO "md: Will configure md%d (%s) from %s, below.\n",
                minor, pername, str);
        md_setup_args.device_names[minor] = str;
 
        return 1;
}
 
extern kdev_t name_to_kdev_t(char *line) md__init;
void md__init md_setup_drive(void)
{
        int minor, i;
        kdev_t dev;
        mddev_t*mddev;
        kdev_t devices[MD_SB_DISKS+1];
 
        for (minor = 0; minor < MAX_MD_DEVS; minor++) {
                int err = 0;
                char *devname;
                mdu_disk_info_t dinfo;
 
                if ((devname = md_setup_args.device_names[minor]) == 0)  continue;
 
                for (i = 0; i < MD_SB_DISKS && devname != 0; i++) {
 
                        char *p;
                        void *handle;
 
                        p = strchr(devname, ',');
                        if (p)
                                *p++ = 0;
 
                        dev = name_to_kdev_t(devname);
                        handle = devfs_find_handle(NULL, devname, MAJOR (dev), MINOR (dev),
                                                        DEVFS_SPECIAL_BLK, 1);
                        if (handle != 0) {
                                unsigned major, minor;
                                devfs_get_maj_min(handle, &major, &minor);
                                dev = MKDEV(major, minor);
                        }
                        if (dev == 0) {
                                printk(KERN_WARNING "md: Unknown device name: %s\n", devname);
                                break;
                        }
 
                        devices[i] = dev;
                        md_setup_args.device_set[minor] = 1;
 
                        devname = p;
                }
                devices[i] = 0;
 
                if (md_setup_args.device_set[minor] == 0)
                        continue;
 
                if (mddev_map[minor].mddev) {
                        printk(KERN_WARNING
                               "md: Ignoring md=%d, already autodetected. (Use raid=noautodetect)\n",
                               minor);
                        continue;
                }
                printk(KERN_INFO "md: Loading md%d: %s\n", minor, md_setup_args.device_names[minor]);
 
                mddev = alloc_mddev(MKDEV(MD_MAJOR,minor));
                if (!mddev) {
                        printk(KERN_ERR "md: kmalloc failed - cannot start array %d\n", minor);
                        continue;
                }
                if (md_setup_args.pers[minor]) {
                        /* non-persistent */
                        mdu_array_info_t ainfo;
                        ainfo.level = pers_to_level(md_setup_args.pers[minor]);
                        ainfo.size = 0;
                        ainfo.nr_disks =0;
                        ainfo.raid_disks =0;
                        ainfo.md_minor =minor;
                        ainfo.not_persistent = 1;
 
                        ainfo.state = (1 << MD_SB_CLEAN);
                        ainfo.active_disks = 0;
                        ainfo.working_disks = 0;
                        ainfo.failed_disks = 0;
                        ainfo.spare_disks = 0;
                        ainfo.layout = 0;
                        ainfo.chunk_size = md_setup_args.chunk[minor];
                        err = set_array_info(mddev, &ainfo);
                        for (i = 0; !err && (dev = devices[i]); i++) {
                                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);
                                mddev->sb->nr_disks++;
                                mddev->sb->raid_disks++;
                                mddev->sb->active_disks++;
                                mddev->sb->working_disks++;
                                err = add_new_disk (mddev, &dinfo);
                        }
                } else {
                        /* persistent */
                        for (i = 0; (dev = devices[i]); i++) {
                                dinfo.major = MAJOR(dev);
                                dinfo.minor = MINOR(dev);
                                add_new_disk (mddev, &dinfo);
                        }
                }
                if (!err)
                        err = do_md_run(mddev);
                if (err) {
                        mddev->sb_dirty = 0;
                        do_md_stop(mddev, 0);
                        printk(KERN_WARNING "md: starting md%d failed\n", minor);
                }
        }
}
 
static int md__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) == 0)
                        raid_setup_args.noautodetect = 1;
                pos += wlen+1;
        }
        raid_setup_args.set = 1;
        return 1;
}
 
int md__init md_run_setup(void)
{
        if (raid_setup_args.noautodetect)
                printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=noautodetect)\n");
        else
                autostart_arrays();
        md_setup_drive();
        return 0;
}
 
__setup("raid=", raid_setup);
__setup("md=", md_setup);
 
__initcall(md_init);
__initcall(md_run_setup);
 
#else /* It is a MODULE */
 
int init_module(void)
{
        return md_init();
}
 
static void free_device_names(void)
{
        while (device_names.next != &device_names) {
                struct list_head *tmp = device_names.next;
                list_del(tmp);
                kfree(tmp);
        }
}
 
 
void cleanup_module(void)
{
        md_unregister_thread(md_recovery_thread);
        devfs_unregister(devfs_handle);
 
        devfs_unregister_blkdev(MAJOR_NR,"md");
        unregister_reboot_notifier(&md_notifier);
        unregister_sysctl_table(raid_table_header);
#ifdef CONFIG_PROC_FS
        remove_proc_entry("mdstat", NULL);
#endif
 
        del_gendisk(&md_gendisk);
 
        blk_dev[MAJOR_NR].queue = NULL;
        blksize_size[MAJOR_NR] = NULL;
        blk_size[MAJOR_NR] = NULL;
        max_readahead[MAJOR_NR] = NULL;
        hardsect_size[MAJOR_NR] = NULL;
 
        free_device_names();
 
}
#endif
 
MD_EXPORT_SYMBOL(md_size);
MD_EXPORT_SYMBOL(register_md_personality);
MD_EXPORT_SYMBOL(unregister_md_personality);
MD_EXPORT_SYMBOL(partition_name);
MD_EXPORT_SYMBOL(md_error);
MD_EXPORT_SYMBOL(md_do_sync);
MD_EXPORT_SYMBOL(md_sync_acct);
MD_EXPORT_SYMBOL(md_done_sync);
MD_EXPORT_SYMBOL(md_recover_arrays);
MD_EXPORT_SYMBOL(md_register_thread);
MD_EXPORT_SYMBOL(md_unregister_thread);
MD_EXPORT_SYMBOL(md_update_sb);
MD_EXPORT_SYMBOL(md_wakeup_thread);
MD_EXPORT_SYMBOL(md_print_devices);
MD_EXPORT_SYMBOL(find_rdev_nr);
MD_EXPORT_SYMBOL(md_interrupt_thread);
MD_EXPORT_SYMBOL(mddev_map);
MD_EXPORT_SYMBOL(md_check_ordering);
MD_EXPORT_SYMBOL(get_spare);
MODULE_LICENSE("GPL");
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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [drivers/] [md/] [md.c] - Blame information for rev 1774

Line No.	Rev	Author	Line
1	1275	phoenix	`/*`
2			`md.c : Multiple Devices driver for Linux`
3			`Copyright (C) 1998, 1999, 2000 Ingo Molnar`
4
5			`completely rewritten, based on the MD driver code from Marc Zyngier`
6
7			`Changes:`
8
9			`- RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar`
10			`- boot support for linear and striped mode by Harald Hoyer <HarryH@Royal.Net>`
11			`- kerneld support by Boris Tobotras <boris@xtalk.msk.su>`
12			`- kmod support by: Cyrus Durgin`
13			`- RAID0 bugfixes: Mark Anthony Lisher <markal@iname.com>`
14			`- Devfs support by Richard Gooch <rgooch@atnf.csiro.au>`
15
16			`- lots of fixes and improvements to the RAID1/RAID5 and generic`
17			`RAID code (such as request based resynchronization):`
18
19			`Neil Brown <neilb@cse.unsw.edu.au>.`
20
21			`This program is free software; you can redistribute it and/or modify`
22			`it under the terms of the GNU General Public License as published by`
23			`the Free Software Foundation; either version 2, or (at your option)`
24			`any later version.`
25
26			`You should have received a copy of the GNU General Public License`
27			`(for example /usr/src/linux/COPYING); if not, write to the Free`
28			`Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.`
29			`*/`
30
31			`#include <linux/module.h>`
32			`#include <linux/config.h>`
33			`#include <linux/raid/md.h>`
34			`#include <linux/sysctl.h>`
35			`#include <linux/raid/xor.h>`
36			`#include <linux/devfs_fs_kernel.h>`
37
38			`#include <linux/init.h>`
39
40			`#ifdef CONFIG_KMOD`