Documentation

/*
   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
   - RAID-6 extensions by H. Peter Anvin <hpa@zytor.com>
   - 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>.

   - persistent bitmap code
     Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.

   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/kthread.h>
#include <linux/blkdev.h>
#include <linux/sysctl.h>
#include <linux/seq_file.h>
#include <linux/mutex.h>
#include <linux/buffer_head.h> /* for invalidate_bdev */
#include <linux/poll.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/hdreg.h>
#include <linux/proc_fs.h>
#include <linux/random.h>
#include <linux/reboot.h>
#include <linux/file.h>
#include <linux/compat.h>
#include <linux/delay.h>
#include <linux/raid/md_p.h>
#include <linux/raid/md_u.h>
#include <linux/slab.h>
#include "md.h"
#include "bitmap.h"

#define DEBUG 0
#define dprintk(x...) ((void)(DEBUG && printk(x)))

#ifndef MODULE
static void autostart_arrays(int part);
#endif

static LIST_HEAD(pers_list);
static DEFINE_SPINLOCK(pers_lock);

static void md_print_devices(void);

static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
static struct workqueue_struct *md_wq;
static struct workqueue_struct *md_misc_wq;

#define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }

/*
 * Default number of read corrections we'll attempt on an rdev
 * before ejecting it from the array. We divide the read error
 * count by 2 for every hour elapsed between read errors.
 */
#define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
/*
 * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
 * is 1000 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 bandwidth 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.
 * or /sys/block/mdX/md/sync_speed_{min,max}
 */

static int sysctl_speed_limit_min = 1000;
static int sysctl_speed_limit_max = 200000;
static inline int speed_min(mddev_t *mddev)
{
	return mddev->sync_speed_min ?
		mddev->sync_speed_min : sysctl_speed_limit_min;
}

static inline int speed_max(mddev_t *mddev)
{
	return mddev->sync_speed_max ?
		mddev->sync_speed_max : sysctl_speed_limit_max;
}

static struct ctl_table_header *raid_table_header;

static ctl_table raid_table[] = {
	{
		.procname	= "speed_limit_min",
		.data		= &sysctl_speed_limit_min,
		.maxlen		= sizeof(int),
		.mode		= S_IRUGO|S_IWUSR,
		.proc_handler	= proc_dointvec,
	},
	{
		.procname	= "speed_limit_max",
		.data		= &sysctl_speed_limit_max,
		.maxlen		= sizeof(int),
		.mode		= S_IRUGO|S_IWUSR,
		.proc_handler	= proc_dointvec,
	},
	{ }
};

static ctl_table raid_dir_table[] = {
	{
		.procname	= "raid",
		.maxlen		= 0,
		.mode		= S_IRUGO|S_IXUGO,
		.child		= raid_table,
	},
	{ }
};

static ctl_table raid_root_table[] = {
	{
		.procname	= "dev",
		.maxlen		= 0,
		.mode		= 0555,
		.child		= raid_dir_table,
	},
	{  }
};

static const struct block_device_operations md_fops;

static int start_readonly;

/* bio_clone_mddev
 * like bio_clone, but with a local bio set
 */

static void mddev_bio_destructor(struct bio *bio)
{
	mddev_t *mddev, **mddevp;

	mddevp = (void*)bio;
	mddev = mddevp[-1];

	bio_free(bio, mddev->bio_set);
}

struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
			    mddev_t *mddev)
{
	struct bio *b;
	mddev_t **mddevp;

	if (!mddev || !mddev->bio_set)
		return bio_alloc(gfp_mask, nr_iovecs);

	b = bio_alloc_bioset(gfp_mask, nr_iovecs,
			     mddev->bio_set);
	if (!b)
		return NULL;
	mddevp = (void*)b;
	mddevp[-1] = mddev;
	b->bi_destructor = mddev_bio_destructor;
	return b;
}
EXPORT_SYMBOL_GPL(bio_alloc_mddev);

struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
			    mddev_t *mddev)
{
	struct bio *b;
	mddev_t **mddevp;

	if (!mddev || !mddev->bio_set)
		return bio_clone(bio, gfp_mask);

	b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs,
			     mddev->bio_set);
	if (!b)
		return NULL;
	mddevp = (void*)b;
	mddevp[-1] = mddev;
	b->bi_destructor = mddev_bio_destructor;
	__bio_clone(b, bio);
	if (bio_integrity(bio)) {
		int ret;

		ret = bio_integrity_clone(b, bio, gfp_mask, mddev->bio_set);

		if (ret < 0) {
			bio_put(b);
			return NULL;
		}
	}

	return b;
}
EXPORT_SYMBOL_GPL(bio_clone_mddev);

/*
 * We have a system wide 'event count' that is incremented
 * on any 'interesting' event, and readers of /proc/mdstat
 * can use 'poll' or 'select' to find out when the event
 * count increases.
 *
 * Events are:
 *  start array, stop array, error, add device, remove device,
 *  start build, activate spare
 */
static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
static atomic_t md_event_count;
void md_new_event(mddev_t *mddev)
{
	atomic_inc(&md_event_count);
	wake_up(&md_event_waiters);
}
EXPORT_SYMBOL_GPL(md_new_event);

/* Alternate version that can be called from interrupts
 * when calling sysfs_notify isn't needed.
 */
static void md_new_event_inintr(mddev_t *mddev)
{
	atomic_inc(&md_event_count);
	wake_up(&md_event_waiters);
}

/*
 * Enables to iterate over all existing md arrays
 * all_mddevs_lock protects this list.
 */
static LIST_HEAD(all_mddevs);
static DEFINE_SPINLOCK(all_mddevs_lock);


/*
 * iterates through all used mddevs in the system.
 * We take care to grab the all_mddevs_lock whenever navigating
 * the list, and to always hold a refcount when unlocked.
 * Any code which breaks out of this loop while own
 * a reference to the current mddev and must mddev_put it.
 */
#define for_each_mddev(mddev,tmp)					\
									\
	for (({ spin_lock(&all_mddevs_lock); 				\
		tmp = all_mddevs.next;					\
		mddev = NULL;});					\
	     ({ if (tmp != &all_mddevs)					\
			mddev_get(list_entry(tmp, mddev_t, all_mddevs));\
		spin_unlock(&all_mddevs_lock);				\
		if (mddev) mddev_put(mddev);				\
		mddev = list_entry(tmp, mddev_t, all_mddevs);		\
		tmp != &all_mddevs;});					\
	     ({ spin_lock(&all_mddevs_lock);				\
		tmp = tmp->next;})					\
		)


/* Rather than calling directly into the personality make_request function,
 * IO requests come here first so that we can check if the device is
 * being suspended pending a reconfiguration.
 * We hold a refcount over the call to ->make_request.  By the time that
 * call has finished, the bio has been linked into some internal structure
 * and so is visible to ->quiesce(), so we don't need the refcount any more.
 */
static int md_make_request(struct request_queue *q, struct bio *bio)
{
	const int rw = bio_data_dir(bio);
	mddev_t *mddev = q->queuedata;
	int rv;
	int cpu;
	unsigned int sectors;

	if (mddev == NULL || mddev->pers == NULL
	    || !mddev->ready) {
		bio_io_error(bio);
		return 0;
	}
	smp_rmb(); /* Ensure implications of  'active' are visible */
	rcu_read_lock();
	if (mddev->suspended) {
		DEFINE_WAIT(__wait);
		for (;;) {
			prepare_to_wait(&mddev->sb_wait, &__wait,
					TASK_UNINTERRUPTIBLE);
			if (!mddev->suspended)
				break;
			rcu_read_unlock();
			schedule();
			rcu_read_lock();
		}
		finish_wait(&mddev->sb_wait, &__wait);
	}
	atomic_inc(&mddev->active_io);
	rcu_read_unlock();

	/*
	 * save the sectors now since our bio can
	 * go away inside make_request
	 */
	sectors = bio_sectors(bio);
	rv = mddev->pers->make_request(mddev, bio);

	cpu = part_stat_lock();
	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
	part_stat_unlock();

	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
		wake_up(&mddev->sb_wait);

	return rv;
}

/* mddev_suspend makes sure no new requests are submitted
 * to the device, and that any requests that have been submitted
 * are completely handled.
 * Once ->stop is called and completes, the module will be completely
 * unused.
 */
void mddev_suspend(mddev_t *mddev)
{
	BUG_ON(mddev->suspended);
	mddev->suspended = 1;
	synchronize_rcu();
	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
	mddev->pers->quiesce(mddev, 1);
}
EXPORT_SYMBOL_GPL(mddev_suspend);

void mddev_resume(mddev_t *mddev)
{
	mddev->suspended = 0;
	wake_up(&mddev->sb_wait);
	mddev->pers->quiesce(mddev, 0);
}
EXPORT_SYMBOL_GPL(mddev_resume);

int mddev_congested(mddev_t *mddev, int bits)
{
	return mddev->suspended;
}
EXPORT_SYMBOL(mddev_congested);

/*
 * Generic flush handling for md
 */

static void md_end_flush(struct bio *bio, int err)
{
	mdk_rdev_t *rdev = bio->bi_private;
	mddev_t *mddev = rdev->mddev;

	rdev_dec_pending(rdev, mddev);

	if (atomic_dec_and_test(&mddev->flush_pending)) {
		/* The pre-request flush has finished */
		queue_work(md_wq, &mddev->flush_work);
	}
	bio_put(bio);
}

static void md_submit_flush_data(struct work_struct *ws);

static void submit_flushes(struct work_struct *ws)
{
	mddev_t *mddev = container_of(ws, mddev_t, flush_work);
	mdk_rdev_t *rdev;

	INIT_WORK(&mddev->flush_work, md_submit_flush_data);
	atomic_set(&mddev->flush_pending, 1);
	rcu_read_lock();
	list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
		if (rdev->raid_disk >= 0 &&
		    !test_bit(Faulty, &rdev->flags)) {
			/* Take two references, one is dropped
			 * when request finishes, one after
			 * we reclaim rcu_read_lock
			 */
			struct bio *bi;
			atomic_inc(&rdev->nr_pending);
			atomic_inc(&rdev->nr_pending);
			rcu_read_unlock();
			bi = bio_alloc_mddev(GFP_KERNEL, 0, mddev);
			bi->bi_end_io = md_end_flush;
			bi->bi_private = rdev;
			bi->bi_bdev = rdev->bdev;
			atomic_inc(&mddev->flush_pending);
			submit_bio(WRITE_FLUSH, bi);
			rcu_read_lock();
			rdev_dec_pending(rdev, mddev);
		}
	rcu_read_unlock();
	if (atomic_dec_and_test(&mddev->flush_pending))
		queue_work(md_wq, &mddev->flush_work);
}

static void md_submit_flush_data(struct work_struct *ws)
{
	mddev_t *mddev = container_of(ws, mddev_t, flush_work);
	struct bio *bio = mddev->flush_bio;

	if (bio->bi_size == 0)
		/* an empty barrier - all done */
		bio_endio(bio, 0);
	else {
		bio->bi_rw &= ~REQ_FLUSH;
		if (mddev->pers->make_request(mddev, bio))
			generic_make_request(bio);
	}

	mddev->flush_bio = NULL;
	wake_up(&mddev->sb_wait);
}

void md_flush_request(mddev_t *mddev, struct bio *bio)
{
	spin_lock_irq(&mddev->write_lock);
	wait_event_lock_irq(mddev->sb_wait,
			    !mddev->flush_bio,
			    mddev->write_lock, /*nothing*/);
	mddev->flush_bio = bio;
	spin_unlock_irq(&mddev->write_lock);

	INIT_WORK(&mddev->flush_work, submit_flushes);
	queue_work(md_wq, &mddev->flush_work);
}
EXPORT_SYMBOL(md_flush_request);

/* Support for plugging.
 * This mirrors the plugging support in request_queue, but does not
 * require having a whole queue
 */
static void plugger_work(struct work_struct *work)
{
	struct plug_handle *plug =
		container_of(work, struct plug_handle, unplug_work);
	plug->unplug_fn(plug);
}
static void plugger_timeout(unsigned long data)
{
	struct plug_handle *plug = (void *)data;
	kblockd_schedule_work(NULL, &plug->unplug_work);
}
void plugger_init(struct plug_handle *plug,
		  void (*unplug_fn)(struct plug_handle *))
{
	plug->unplug_flag = 0;
	plug->unplug_fn = unplug_fn;
	init_timer(&plug->unplug_timer);
	plug->unplug_timer.function = plugger_timeout;
	plug->unplug_timer.data = (unsigned long)plug;
	INIT_WORK(&plug->unplug_work, plugger_work);
}
EXPORT_SYMBOL_GPL(plugger_init);

void plugger_set_plug(struct plug_handle *plug)
{
	if (!test_and_set_bit(PLUGGED_FLAG, &plug->unplug_flag))
		mod_timer(&plug->unplug_timer, jiffies + msecs_to_jiffies(3)+1);
}
EXPORT_SYMBOL_GPL(plugger_set_plug);

int plugger_remove_plug(struct plug_handle *plug)
{
	if (test_and_clear_bit(PLUGGED_FLAG, &plug->unplug_flag)) {
		del_timer(&plug->unplug_timer);
		return 1;
	} else
		return 0;
}
EXPORT_SYMBOL_GPL(plugger_remove_plug);


static inline mddev_t *mddev_get(mddev_t *mddev)
{
	atomic_inc(&mddev->active);
	return mddev;
}

static void mddev_delayed_delete(struct work_struct *ws);

static void mddev_put(mddev_t *mddev)
{
	struct bio_set *bs = NULL;

	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
		return;
	if (!mddev->raid_disks && list_empty(&mddev->disks) &&
	    mddev->ctime == 0 && !mddev->hold_active) {
		/* Array is not configured at all, and not held active,
		 * so destroy it */
		list_del(&mddev->all_mddevs);
		bs = mddev->bio_set;
		mddev->bio_set = NULL;
		if (mddev->gendisk) {
			/* We did a probe so need to clean up.  Call
			 * queue_work inside the spinlock so that
			 * flush_workqueue() after mddev_find will
			 * succeed in waiting for the work to be done.
			 */
			INIT_WORK(&mddev->del_work, mddev_delayed_delete);
			queue_work(md_misc_wq, &mddev->del_work);
		} else
			kfree(mddev);
	}
	spin_unlock(&all_mddevs_lock);
	if (bs)
		bioset_free(bs);
}

void mddev_init(mddev_t *mddev)
{
	mutex_init(&mddev->open_mutex);
	mutex_init(&mddev->reconfig_mutex);
	mutex_init(&mddev->bitmap_info.mutex);
	INIT_LIST_HEAD(&mddev->disks);
	INIT_LIST_HEAD(&mddev->all_mddevs);
	init_timer(&mddev->safemode_timer);
	atomic_set(&mddev->active, 1);
	atomic_set(&mddev->openers, 0);
	atomic_set(&mddev->active_io, 0);
	spin_lock_init(&mddev->write_lock);
	atomic_set(&mddev->flush_pending, 0);
	init_waitqueue_head(&mddev->sb_wait);
	init_waitqueue_head(&mddev->recovery_wait);
	mddev->reshape_position = MaxSector;
	mddev->resync_min = 0;
	mddev->resync_max = MaxSector;
	mddev->level = LEVEL_NONE;
}
EXPORT_SYMBOL_GPL(mddev_init);

static mddev_t * mddev_find(dev_t unit)
{
	mddev_t *mddev, *new = NULL;

	if (unit && MAJOR(unit) != MD_MAJOR)
		unit &= ~((1<<MdpMinorShift)-1);

 retry:
	spin_lock(&all_mddevs_lock);

	if (unit) {
		list_for_each_entry(mddev, &all_mddevs, all_mddevs)
			if (mddev->unit == unit) {
				mddev_get(mddev);
				spin_unlock(&all_mddevs_lock);
				kfree(new);
				return mddev;
			}

		if (new) {
			list_add(&new->all_mddevs, &all_mddevs);
			spin_unlock(&all_mddevs_lock);
			new->hold_active = UNTIL_IOCTL;
			return new;
		}
	} else if (new) {
		/* find an unused unit number */
		static int next_minor = 512;
		int start = next_minor;
		int is_free = 0;
		int dev = 0;
		while (!is_free) {
			dev = MKDEV(MD_MAJOR, next_minor);
			next_minor++;
			if (next_minor > MINORMASK)
				next_minor = 0;
			if (next_minor == start) {
				/* Oh dear, all in use. */
				spin_unlock(&all_mddevs_lock);
				kfree(new);
				return NULL;
			}
				
			is_free = 1;
			list_for_each_entry(mddev, &all_mddevs, all_mddevs)
				if (mddev->unit == dev) {
					is_free = 0;
					break;
				}
		}
		new->unit = dev;
		new->md_minor = MINOR(dev);
		new->hold_active = UNTIL_STOP;
		list_add(&new->all_mddevs, &all_mddevs);
		spin_unlock(&all_mddevs_lock);
		return new;
	}
	spin_unlock(&all_mddevs_lock);

	new = kzalloc(sizeof(*new), GFP_KERNEL);
	if (!new)
		return NULL;

	new->unit = unit;
	if (MAJOR(unit) == MD_MAJOR)
		new->md_minor = MINOR(unit);
	else
		new->md_minor = MINOR(unit) >> MdpMinorShift;

	mddev_init(new);

	goto retry;
}

static inline int mddev_lock(mddev_t * mddev)
{
	return mutex_lock_interruptible(&mddev->reconfig_mutex);
}

static inline int mddev_is_locked(mddev_t *mddev)
{
	return mutex_is_locked(&mddev->reconfig_mutex);
}

static inline int mddev_trylock(mddev_t * mddev)
{
	return mutex_trylock(&mddev->reconfig_mutex);
}

static struct attribute_group md_redundancy_group;

static void mddev_unlock(mddev_t * mddev)
{
	if (mddev->to_remove) {
		/* These cannot be removed under reconfig_mutex as
		 * an access to the files will try to take reconfig_mutex
		 * while holding the file unremovable, which leads to
		 * a deadlock.
		 * So hold set sysfs_active while the remove in happeing,
		 * and anything else which might set ->to_remove or my
		 * otherwise change the sysfs namespace will fail with
		 * -EBUSY if sysfs_active is still set.
		 * We set sysfs_active under reconfig_mutex and elsewhere
		 * test it under the same mutex to ensure its correct value
		 * is seen.
		 */
		struct attribute_group *to_remove = mddev->to_remove;
		mddev->to_remove = NULL;
		mddev->sysfs_active = 1;
		mutex_unlock(&mddev->reconfig_mutex);

		if (mddev->kobj.sd) {
			if (to_remove != &md_redundancy_group)
				sysfs_remove_group(&mddev->kobj, to_remove);
			if (mddev->pers == NULL ||
			    mddev->pers->sync_request == NULL) {
				sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
				if (mddev->sysfs_action)
					sysfs_put(mddev->sysfs_action);
				mddev->sysfs_action = NULL;
			}
		}
		mddev->sysfs_active = 0;
	} else
		mutex_unlock(&mddev->reconfig_mutex);

	md_wakeup_thread(mddev->thread);
}

static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
{
	mdk_rdev_t *rdev;

	list_for_each_entry(rdev, &mddev->disks, same_set)
		if (rdev->desc_nr == nr)
			return rdev;

	return NULL;
}

static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
{
	mdk_rdev_t *rdev;

	list_for_each_entry(rdev, &mddev->disks, same_set)
		if (rdev->bdev->bd_dev == dev)
			return rdev;

	return NULL;
}

static struct mdk_personality *find_pers(int level, char *clevel)
{
	struct mdk_personality *pers;
	list_for_each_entry(pers, &pers_list, list) {
		if (level != LEVEL_NONE && pers->level == level)
			return pers;
		if (strcmp(pers->name, clevel)==0)
			return pers;
	}
	return NULL;
}

/* return the offset of the super block in 512byte sectors */
static inline sector_t calc_dev_sboffset(mdk_rdev_t *rdev)
{
	sector_t num_sectors = i_size_read(rdev->bdev->bd_inode) / 512;
	return MD_NEW_SIZE_SECTORS(num_sectors);
}

static int alloc_disk_sb(mdk_rdev_t * rdev)
{
	if (rdev->sb_page)
		MD_BUG();

	rdev->sb_page = alloc_page(GFP_KERNEL);
	if (!rdev->sb_page) {
		printk(KERN_ALERT "md: out of memory.\n");
		return -ENOMEM;
	}

	return 0;
}

static void free_disk_sb(mdk_rdev_t * rdev)
{
	if (rdev->sb_page) {
		put_page(rdev->sb_page);
		rdev->sb_loaded = 0;
		rdev->sb_page = NULL;
		rdev->sb_start = 0;
		rdev->sectors = 0;
	}
}


static void super_written(struct bio *bio, int error)
{
	mdk_rdev_t *rdev = bio->bi_private;
	mddev_t *mddev = rdev->mddev;

	if (error || !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
		printk("md: super_written gets error=%d, uptodate=%d\n",
		       error, test_bit(BIO_UPTODATE, &bio->bi_flags));
		WARN_ON(test_bit(BIO_UPTODATE, &bio->bi_flags));
		md_error(mddev, rdev);
	}

	if (atomic_dec_and_test(&mddev->pending_writes))
		wake_up(&mddev->sb_wait);
	bio_put(bio);
}

void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
		   sector_t sector, int size, struct page *page)
{
	/* write first size bytes of page to sector of rdev
	 * Increment mddev->pending_writes before returning
	 * and decrement it on completion, waking up sb_wait
	 * if zero is reached.
	 * If an error occurred, call md_error
	 */
	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);

	bio->bi_bdev = rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev;
	bio->bi_sector = sector;
	bio_add_page(bio, page, size, 0);
	bio->bi_private = rdev;
	bio->bi_end_io = super_written;

	atomic_inc(&mddev->pending_writes);
	submit_bio(REQ_WRITE | REQ_SYNC | REQ_UNPLUG | REQ_FLUSH | REQ_FUA,
		   bio);
}

void md_super_wait(mddev_t *mddev)
{
	/* wait for all superblock writes that were scheduled to complete */
	DEFINE_WAIT(wq);
	for(;;) {
		prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
		if (atomic_read(&mddev->pending_writes)==0)
			break;
		schedule();
	}
	finish_wait(&mddev->sb_wait, &wq);
}

static void bi_complete(struct bio *bio, int error)
{
	complete((struct completion*)bio->bi_private);
}

int sync_page_io(mdk_rdev_t *rdev, sector_t sector, int size,
		 struct page *page, int rw, bool metadata_op)
{
	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
	struct completion event;
	int ret;

	rw |= REQ_SYNC | REQ_UNPLUG;

	bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
		rdev->meta_bdev : rdev->bdev;
	if (metadata_op)
		bio->bi_sector = sector + rdev->sb_start;
	else
		bio->bi_sector = sector + rdev->data_offset;
	bio_add_page(bio, page, size, 0);
	init_completion(&event);
	bio->bi_private = &event;
	bio->bi_end_io = bi_complete;
	submit_bio(rw, bio);
	wait_for_completion(&event);

	ret = test_bit(BIO_UPTODATE, &bio->bi_flags);
	bio_put(bio);
	return ret;
}
EXPORT_SYMBOL_GPL(sync_page_io);

static int read_disk_sb(mdk_rdev_t * rdev, int size)
{
	char b[BDEVNAME_SIZE];
	if (!rdev->sb_page) {
		MD_BUG();
		return -EINVAL;
	}
	if (rdev->sb_loaded)
		return 0;


	if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, true))
		goto fail;
	rdev->sb_loaded = 1;
	return 0;

fail:
	printk(KERN_WARNING "md: disabled device %s, could not read superblock.\n",
		bdevname(rdev->bdev,b));
	return -EINVAL;
}

static int uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
{
	return 	sb1->set_uuid0 == sb2->set_uuid0 &&
		sb1->set_uuid1 == sb2->set_uuid1 &&
		sb1->set_uuid2 == sb2->set_uuid2 &&
		sb1->set_uuid3 == sb2->set_uuid3;
}

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 sb_equal(): failed to allocate memory!\n");
		goto abort;
	}

	*tmp1 = *sb1;
	*tmp2 = *sb2;

	/*
	 * nr_disks is not constant
	 */
	tmp1->nr_disks = 0;
	tmp2->nr_disks = 0;

	ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
abort:
	kfree(tmp1);
	kfree(tmp2);
	return ret;
}


static u32 md_csum_fold(u32 csum)
{
	csum = (csum & 0xffff) + (csum >> 16);
	return (csum & 0xffff) + (csum >> 16);
}

static unsigned int calc_sb_csum(mdp_super_t * sb)
{
	u64 newcsum = 0;
	u32 *sb32 = (u32*)sb;
	int i;
	unsigned int disk_csum, csum;

	disk_csum = sb->sb_csum;
	sb->sb_csum = 0;

	for (i = 0; i < MD_SB_BYTES/4 ; i++)
		newcsum += sb32[i];
	csum = (newcsum & 0xffffffff) + (newcsum>>32);


#ifdef CONFIG_ALPHA
	/* This used to use csum_partial, which was wrong for several
	 * reasons including that different results are returned on
	 * different architectures.  It isn't critical that we get exactly
	 * the same return value as before (we always csum_fold before
	 * testing, and that removes any differences).  However as we
	 * know that csum_partial always returned a 16bit value on
	 * alphas, do a fold to maximise conformity to previous behaviour.
	 */
	sb->sb_csum = md_csum_fold(disk_csum);
#else
	sb->sb_csum = disk_csum;
#endif
	return csum;
}


/*
 * Handle superblock details.
 * We want to be able to handle multiple superblock formats
 * so we have a common interface to them all, and an array of
 * different handlers.
 * We rely on user-space to write the initial superblock, and support
 * reading and updating of superblocks.
 * Interface methods are:
 *   int load_super(mdk_rdev_t *dev, mdk_rdev_t *refdev, int minor_version)
 *      loads and validates a superblock on dev.
 *      if refdev != NULL, compare superblocks on both devices
 *    Return:
 *      0 - dev has a superblock that is compatible with refdev
 *      1 - dev has a superblock that is compatible and newer than refdev
 *          so dev should be used as the refdev in future
 *     -EINVAL superblock incompatible or invalid
 *     -othererror e.g. -EIO
 *
 *   int validate_super(mddev_t *mddev, mdk_rdev_t *dev)
 *      Verify that dev is acceptable into mddev.
 *       The first time, mddev->raid_disks will be 0, and data from
 *       dev should be merged in.  Subsequent calls check that dev
 *       is new enough.  Return 0 or -EINVAL
 *
 *   void sync_super(mddev_t *mddev, mdk_rdev_t *dev)
 *     Update the superblock for rdev with data in mddev
 *     This does not write to disc.
 *
 */

struct super_type  {
	char		    *name;
	struct module	    *owner;
	int		    (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev,
					  int minor_version);
	int		    (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
	void		    (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
	unsigned long long  (*rdev_size_change)(mdk_rdev_t *rdev,
						sector_t num_sectors);
};

/*
 * Check that the given mddev has no bitmap.
 *
 * This function is called from the run method of all personalities that do not
 * support bitmaps. It prints an error message and returns non-zero if mddev
 * has a bitmap. Otherwise, it returns 0.
 *
 */
int md_check_no_bitmap(mddev_t *mddev)
{
	if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
		return 0;
	printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
		mdname(mddev), mddev->pers->name);
	return 1;
}
EXPORT_SYMBOL(md_check_no_bitmap);

/*
 * load_super for 0.90.0 
 */
static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
{
	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
	mdp_super_t *sb;
	int ret;

	/*
	 * Calculate the position of the superblock (512byte sectors),
	 * it's at the end of the disk.
	 *
	 * It also happens to be a multiple of 4Kb.
	 */
	rdev->sb_start = calc_dev_sboffset(rdev);

	ret = read_disk_sb(rdev, MD_SB_BYTES);
	if (ret) return ret;

	ret = -EINVAL;

	bdevname(rdev->bdev, b);
	sb = (mdp_super_t*)page_address(rdev->sb_page);

	if (sb->md_magic != MD_SB_MAGIC) {
		printk(KERN_ERR "md: invalid raid superblock magic on %s\n",
		       b);
		goto abort;
	}

	if (sb->major_version != 0 ||
	    sb->minor_version < 90 ||
	    sb->minor_version > 91) {
		printk(KERN_WARNING "Bad version number %d.%d on %s\n",
			sb->major_version, sb->minor_version,
			b);
		goto abort;
	}

	if (sb->raid_disks <= 0)
		goto abort;

	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
		printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
			b);
		goto abort;
	}

	rdev->preferred_minor = sb->md_minor;
	rdev->data_offset = 0;
	rdev->sb_size = MD_SB_BYTES;

	if (sb->level == LEVEL_MULTIPATH)
		rdev->desc_nr = -1;
	else
		rdev->desc_nr = sb->this_disk.number;

	if (!refdev) {
		ret = 1;
	} else {
		__u64 ev1, ev2;
		mdp_super_t *refsb = (mdp_super_t*)page_address(refdev->sb_page);
		if (!uuid_equal(refsb, sb)) {
			printk(KERN_WARNING "md: %s has different UUID to %s\n",
				b, bdevname(refdev->bdev,b2));
			goto abort;
		}
		if (!sb_equal(refsb, sb)) {
			printk(KERN_WARNING "md: %s has same UUID"
			       " but different superblock to %s\n",
			       b, bdevname(refdev->bdev, b2));
			goto abort;
		}
		ev1 = md_event(sb);
		ev2 = md_event(refsb);
		if (ev1 > ev2)
			ret = 1;
		else 
			ret = 0;
	}
	rdev->sectors = rdev->sb_start;

	if (rdev->sectors < sb->size * 2 && sb->level > 1)
		/* "this cannot possibly happen" ... */
		ret = -EINVAL;

 abort:
	return ret;
}

/*
 * validate_super for 0.90.0
 */
static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
{
	mdp_disk_t *desc;
	mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
	__u64 ev1 = md_event(sb);

	rdev->raid_disk = -1;
	clear_bit(Faulty, &rdev->flags);
	clear_bit(In_sync, &rdev->flags);
	clear_bit(WriteMostly, &rdev->flags);

	if (mddev->raid_disks == 0) {
		mddev->major_version = 0;
		mddev->minor_version = sb->minor_version;
		mddev->patch_version = sb->patch_version;
		mddev->external = 0;
		mddev->chunk_sectors = sb->chunk_size >> 9;
		mddev->ctime = sb->ctime;
		mddev->utime = sb->utime;
		mddev->level = sb->level;
		mddev->clevel[0] = 0;
		mddev->layout = sb->layout;
		mddev->raid_disks = sb->raid_disks;
		mddev->dev_sectors = sb->size * 2;
		mddev->events = ev1;
		mddev->bitmap_info.offset = 0;
		mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;

		if (mddev->minor_version >= 91) {
			mddev->reshape_position = sb->reshape_position;
			mddev->delta_disks = sb->delta_disks;
			mddev->new_level = sb->new_level;
			mddev->new_layout = sb->new_layout;
			mddev->new_chunk_sectors = sb->new_chunk >> 9;
		} else {
			mddev->reshape_position = MaxSector;
			mddev->delta_disks = 0;
			mddev->new_level = mddev->level;
			mddev->new_layout = mddev->layout;
			mddev->new_chunk_sectors = mddev->chunk_sectors;
		}

		if (sb->state & (1<<MD_SB_CLEAN))
			mddev->recovery_cp = MaxSector;
		else {
			if (sb->events_hi == sb->cp_events_hi && 
				sb->events_lo == sb->cp_events_lo) {
				mddev->recovery_cp = sb->recovery_cp;
			} else
				mddev->recovery_cp = 0;
		}

		memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
		memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
		memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
		memcpy(mddev->uuid+12,&sb->set_uuid3, 4);

		mddev->max_disks = MD_SB_DISKS;

		if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
		    mddev->bitmap_info.file == NULL)
			mddev->bitmap_info.offset =
				mddev->bitmap_info.default_offset;

	} else if (mddev->pers == NULL) {
		/* Insist on good event counter while assembling, except
		 * for spares (which don't need an event count) */
		++ev1;
		if (sb->disks[rdev->desc_nr].state & (
			    (1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
			if (ev1 < mddev->events) 
				return -EINVAL;
	} else if (mddev->bitmap) {
		/* if adding to array with a bitmap, then we can accept an
		 * older device ... but not too old.
		 */
		if (ev1 < mddev->bitmap->events_cleared)
			return 0;
	} else {
		if (ev1 < mddev->events)
			/* just a hot-add of a new device, leave raid_disk at -1 */
			return 0;
	}

	if (mddev->level != LEVEL_MULTIPATH) {
		desc = sb->disks + rdev->desc_nr;

		if (desc->state & (1<<MD_DISK_FAULTY))
			set_bit(Faulty, &rdev->flags);
		else if (desc->state & (1<<MD_DISK_SYNC) /* &&
			    desc->raid_disk < mddev->raid_disks */) {
			set_bit(In_sync, &rdev->flags);
			rdev->raid_disk = desc->raid_disk;
		} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
			/* active but not in sync implies recovery up to
			 * reshape position.  We don't know exactly where
			 * that is, so set to zero for now */
			if (mddev->minor_version >= 91) {
				rdev->recovery_offset = 0;
				rdev->raid_disk = desc->raid_disk;
			}
		}
		if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
			set_bit(WriteMostly, &rdev->flags);
	} else /* MULTIPATH are always insync */
		set_bit(In_sync, &rdev->flags);
	return 0;
}

/*
 * sync_super for 0.90.0
 */
static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
{
	mdp_super_t *sb;
	mdk_rdev_t *rdev2;
	int next_spare = mddev->raid_disks;


	/* make rdev->sb match mddev data..
	 *
	 * 1/ zero out disks
	 * 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
	 * 3/ any empty disks < next_spare become removed
	 *
	 * disks[0] gets initialised to REMOVED because
	 * we cannot be sure from other fields if it has
	 * been initialised or not.
	 */
	int i;
	int active=0, working=0,failed=0,spare=0,nr_disks=0;

	rdev->sb_size = MD_SB_BYTES;

	sb = (mdp_super_t*)page_address(rdev->sb_page);

	memset(sb, 0, sizeof(*sb));

	sb->md_magic = MD_SB_MAGIC;
	sb->major_version = mddev->major_version;
	sb->patch_version = mddev->patch_version;
	sb->gvalid_words  = 0; /* ignored */
	memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
	memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
	memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
	memcpy(&sb->set_uuid3, mddev->uuid+12,4);

	sb->ctime = mddev->ctime;
	sb->level = mddev->level;
	sb->size = mddev->dev_sectors / 2;
	sb->raid_disks = mddev->raid_disks;
	sb->md_minor = mddev->md_minor;
	sb->not_persistent = 0;
	sb->utime = mddev->utime;
	sb->state = 0;
	sb->events_hi = (mddev->events>>32);
	sb->events_lo = (u32)mddev->events;

	if (mddev->reshape_position == MaxSector)
		sb->minor_version = 90;
	else {
		sb->minor_version = 91;
		sb->reshape_position = mddev->reshape_position;
		sb->new_level = mddev->new_level;
		sb->delta_disks = mddev->delta_disks;
		sb->new_layout = mddev->new_layout;
		sb->new_chunk = mddev->new_chunk_sectors << 9;
	}
	mddev->minor_version = sb->minor_version;
	if (mddev->in_sync)
	{
		sb->recovery_cp = mddev->recovery_cp;
		sb->cp_events_hi = (mddev->events>>32);
		sb->cp_events_lo = (u32)mddev->events;
		if (mddev->recovery_cp == MaxSector)
			sb->state = (1<< MD_SB_CLEAN);
	} else
		sb->recovery_cp = 0;

	sb->layout = mddev->layout;
	sb->chunk_size = mddev->chunk_sectors << 9;

	if (mddev->bitmap && mddev->bitmap_info.file == NULL)
		sb->state |= (1<<MD_SB_BITMAP_PRESENT);

	sb->disks[0].state = (1<<MD_DISK_REMOVED);
	list_for_each_entry(rdev2, &mddev->disks, same_set) {
		mdp_disk_t *d;
		int desc_nr;
		int is_active = test_bit(In_sync, &rdev2->flags);

		if (rdev2->raid_disk >= 0 &&
		    sb->minor_version >= 91)
			/* we have nowhere to store the recovery_offset,
			 * but if it is not below the reshape_position,
			 * we can piggy-back on that.
			 */
			is_active = 1;
		if (rdev2->raid_disk < 0 ||
		    test_bit(Faulty, &rdev2->flags))
			is_active = 0;
		if (is_active)
			desc_nr = rdev2->raid_disk;
		else
			desc_nr = next_spare++;
		rdev2->desc_nr = desc_nr;
		d = &sb->disks[rdev2->desc_nr];
		nr_disks++;
		d->number = rdev2->desc_nr;
		d->major = MAJOR(rdev2->bdev->bd_dev);
		d->minor = MINOR(rdev2->bdev->bd_dev);
		if (is_active)
			d->raid_disk = rdev2->raid_disk;
		else
			d->raid_disk = rdev2->desc_nr; /* compatibility */
		if (test_bit(Faulty, &rdev2->flags))
			d->state = (1<<MD_DISK_FAULTY);
		else if (is_active) {
			d->state = (1<<MD_DISK_ACTIVE);
			if (test_bit(In_sync, &rdev2->flags))
				d->state |= (1<<MD_DISK_SYNC);
			active++;
			working++;
		} else {
			d->state = 0;
			spare++;
			working++;
		}
		if (test_bit(WriteMostly, &rdev2->flags))
			d->state |= (1<<MD_DISK_WRITEMOSTLY);
	}
	/* now set the "removed" and "faulty" bits on any missing devices */
	for (i=0 ; i < mddev->raid_disks ; i++) {
		mdp_disk_t *d = &sb->disks[i];
		if (d->state == 0 && d->number == 0) {
			d->number = i;
			d->raid_disk = i;
			d->state = (1<<MD_DISK_REMOVED);
			d->state |= (1<<MD_DISK_FAULTY);
			failed++;
		}
	}
	sb->nr_disks = nr_disks;
	sb->active_disks = active;
	sb->working_disks = working;
	sb->failed_disks = failed;
	sb->spare_disks = spare;

	sb->this_disk = sb->disks[rdev->desc_nr];
	sb->sb_csum = calc_sb_csum(sb);
}

/*
 * rdev_size_change for 0.90.0
 */
static unsigned long long
super_90_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
{
	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
		return 0; /* component must fit device */
	if (rdev->mddev->bitmap_info.offset)
		return 0; /* can't move bitmap */
	rdev->sb_start = calc_dev_sboffset(rdev);
	if (!num_sectors || num_sectors > rdev->sb_start)
		num_sectors = rdev->sb_start;
	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
		       rdev->sb_page);
	md_super_wait(rdev->mddev);
	return num_sectors;
}


/*
 * version 1 superblock
 */

static __le32 calc_sb_1_csum(struct mdp_superblock_1 * sb)
{
	__le32 disk_csum;
	u32 csum;
	unsigned long long newcsum;
	int size = 256 + le32_to_cpu(sb->max_dev)*2;
	__le32 *isuper = (__le32*)sb;
	int i;

	disk_csum = sb->sb_csum;
	sb->sb_csum = 0;
	newcsum = 0;
	for (i=0; size>=4; size -= 4 )
		newcsum += le32_to_cpu(*isuper++);

	if (size == 2)
		newcsum += le16_to_cpu(*(__le16*) isuper);

	csum = (newcsum & 0xffffffff) + (newcsum >> 32);
	sb->sb_csum = disk_csum;
	return cpu_to_le32(csum);
}

static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
{
	struct mdp_superblock_1 *sb;
	int ret;
	sector_t sb_start;
	char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
	int bmask;

	/*
	 * Calculate the position of the superblock in 512byte sectors.
	 * It is always aligned to a 4K boundary and
	 * depeding on minor_version, it can be:
	 * 0: At least 8K, but less than 12K, from end of device
	 * 1: At start of device
	 * 2: 4K from start of device.
	 */
	switch(minor_version) {
	case 0:
		sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
		sb_start -= 8*2;
		sb_start &= ~(sector_t)(4*2-1);
		break;
	case 1:
		sb_start = 0;
		break;
	case 2:
		sb_start = 8;
		break;
	default:
		return -EINVAL;
	}
	rdev->sb_start = sb_start;

	/* superblock is rarely larger than 1K, but it can be larger,
	 * and it is safe to read 4k, so we do that
	 */
	ret = read_disk_sb(rdev, 4096);
	if (ret) return ret;


	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);

	if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
	    sb->major_version != cpu_to_le32(1) ||
	    le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
	    le64_to_cpu(sb->super_offset) != rdev->sb_start ||
	    (le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
		return -EINVAL;

	if (calc_sb_1_csum(sb) != sb->sb_csum) {
		printk("md: invalid superblock checksum on %s\n",
			bdevname(rdev->bdev,b));
		return -EINVAL;
	}
	if (le64_to_cpu(sb->data_size) < 10) {
		printk("md: data_size too small on %s\n",
		       bdevname(rdev->bdev,b));
		return -EINVAL;
	}

	rdev->preferred_minor = 0xffff;
	rdev->data_offset = le64_to_cpu(sb->data_offset);
	atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));

	rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
	bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
	if (rdev->sb_size & bmask)
		rdev->sb_size = (rdev->sb_size | bmask) + 1;

	if (minor_version
	    && rdev->data_offset < sb_start + (rdev->sb_size/512))
		return -EINVAL;

	if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
		rdev->desc_nr = -1;
	else
		rdev->desc_nr = le32_to_cpu(sb->dev_number);

	if (!refdev) {
		ret = 1;
	} else {
		__u64 ev1, ev2;
		struct mdp_superblock_1 *refsb = 
			(struct mdp_superblock_1*)page_address(refdev->sb_page);

		if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
		    sb->level != refsb->level ||
		    sb->layout != refsb->layout ||
		    sb->chunksize != refsb->chunksize) {
			printk(KERN_WARNING "md: %s has strangely different"
				" superblock to %s\n",
				bdevname(rdev->bdev,b),
				bdevname(refdev->bdev,b2));
			return -EINVAL;
		}
		ev1 = le64_to_cpu(sb->events);
		ev2 = le64_to_cpu(refsb->events);

		if (ev1 > ev2)
			ret = 1;
		else
			ret = 0;
	}
	if (minor_version)
		rdev->sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
			le64_to_cpu(sb->data_offset);
	else
		rdev->sectors = rdev->sb_start;
	if (rdev->sectors < le64_to_cpu(sb->data_size))
		return -EINVAL;
	rdev->sectors = le64_to_cpu(sb->data_size);
	if (le64_to_cpu(sb->size) > rdev->sectors)
		return -EINVAL;
	return ret;
}

static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
{
	struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
	__u64 ev1 = le64_to_cpu(sb->events);

	rdev->raid_disk = -1;
	clear_bit(Faulty, &rdev->flags);
	clear_bit(In_sync, &rdev->flags);
	clear_bit(WriteMostly, &rdev->flags);

	if (mddev->raid_disks == 0) {
		mddev->major_version = 1;
		mddev->patch_version = 0;
		mddev->external = 0;
		mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
		mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
		mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
		mddev->level = le32_to_cpu(sb->level);
		mddev->clevel[0] = 0;
		mddev->layout = le32_to_cpu(sb->layout);
		mddev->raid_disks = le32_to_cpu(sb->raid_disks);
		mddev->dev_sectors = le64_to_cpu(sb->size);
		mddev->events = ev1;
		mddev->bitmap_info.offset = 0;
		mddev->bitmap_info.default_offset = 1024 >> 9;
		
		mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
		memcpy(mddev->uuid, sb->set_uuid, 16);

		mddev->max_disks =  (4096-256)/2;

		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
		    mddev->bitmap_info.file == NULL )
			mddev->bitmap_info.offset =
				(__s32)le32_to_cpu(sb->bitmap_offset);

		if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
			mddev->delta_disks = le32_to_cpu(sb->delta_disks);
			mddev->new_level = le32_to_cpu(sb->new_level);
			mddev->new_layout = le32_to_cpu(sb->new_layout);
			mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
		} else {
			mddev->reshape_position = MaxSector;
			mddev->delta_disks = 0;
			mddev->new_level = mddev->level;
			mddev->new_layout = mddev->layout;
			mddev->new_chunk_sectors = mddev->chunk_sectors;
		}

	} else if (mddev->pers == NULL) {
		/* Insist of good event counter while assembling, except for
		 * spares (which don't need an event count) */
		++ev1;
		if (rdev->desc_nr >= 0 &&
		    rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
		    le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < 0xfffe)
			if (ev1 < mddev->events)
				return -EINVAL;
	} else if (mddev->bitmap) {
		/* If adding to array with a bitmap, then we can accept an
		 * older device, but not too old.
		 */
		if (ev1 < mddev->bitmap->events_cleared)
			return 0;
	} else {
		if (ev1 < mddev->events)
			/* just a hot-add of a new device, leave raid_disk at -1 */
			return 0;
	}
	if (mddev->level != LEVEL_MULTIPATH) {
		int role;
		if (rdev->desc_nr < 0 ||
		    rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
			role = 0xffff;
			rdev->desc_nr = -1;
		} else
			role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
		switch(role) {
		case 0xffff: /* spare */
			break;
		case 0xfffe: /* faulty */
			set_bit(Faulty, &rdev->flags);
			break;
		default:
			if ((le32_to_cpu(sb->feature_map) &
			     MD_FEATURE_RECOVERY_OFFSET))
				rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
			else
				set_bit(In_sync, &rdev->flags);
			rdev->raid_disk = role;
			break;
		}
		if (sb->devflags & WriteMostly1)
			set_bit(WriteMostly, &rdev->flags);
	} else /* MULTIPATH are always insync */
		set_bit(In_sync, &rdev->flags);

	return 0;
}

static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
{
	struct mdp_superblock_1 *sb;
	mdk_rdev_t *rdev2;
	int max_dev, i;
	/* make rdev->sb match mddev and rdev data. */

	sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);

	sb->feature_map = 0;
	sb->pad0 = 0;
	sb->recovery_offset = cpu_to_le64(0);
	memset(sb->pad1, 0, sizeof(sb->pad1));
	memset(sb->pad2, 0, sizeof(sb->pad2));
	memset(sb->pad3, 0, sizeof(sb->pad3));

	sb->utime = cpu_to_le64((__u64)mddev->utime);
	sb->events = cpu_to_le64(mddev->events);
	if (mddev->in_sync)
		sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
	else
		sb->resync_offset = cpu_to_le64(0);

	sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));

	sb->raid_disks = cpu_to_le32(mddev->raid_disks);
	sb->size = cpu_to_le64(mddev->dev_sectors);
	sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
	sb->level = cpu_to_le32(mddev->level);
	sb->layout = cpu_to_le32(mddev->layout);

	if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
		sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
		sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
	}

	if (rdev->raid_disk >= 0 &&
	    !test_bit(In_sync, &rdev->flags)) {
		sb->feature_map |=
			cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
		sb->recovery_offset =
			cpu_to_le64(rdev->recovery_offset);
	}

	if (mddev->reshape_position != MaxSector) {
		sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
		sb->reshape_position = cpu_to_le64(mddev->reshape_position);
		sb->new_layout = cpu_to_le32(mddev->new_layout);
		sb->delta_disks = cpu_to_le32(mddev->delta_disks);
		sb->new_level = cpu_to_le32(mddev->new_level);
		sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
	}

	max_dev = 0;
	list_for_each_entry(rdev2, &mddev->disks, same_set)
		if (rdev2->desc_nr+1 > max_dev)
			max_dev = rdev2->desc_nr+1;

	if (max_dev > le32_to_cpu(sb->max_dev)) {
		int bmask;
		sb->max_dev = cpu_to_le32(max_dev);
		rdev->sb_size = max_dev * 2 + 256;
		bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
		if (rdev->sb_size & bmask)
			rdev->sb_size = (rdev->sb_size | bmask) + 1;
	} else
		max_dev = le32_to_cpu(sb->max_dev);

	for (i=0; i<max_dev;i++)
		sb->dev_roles[i] = cpu_to_le16(0xfffe);
	
	list_for_each_entry(rdev2, &mddev->disks, same_set) {
		i = rdev2->desc_nr;
		if (test_bit(Faulty, &rdev2->flags))
			sb->dev_roles[i] = cpu_to_le16(0xfffe);
		else if (test_bit(In_sync, &rdev2->flags))
			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
		else if (rdev2->raid_disk >= 0)
			sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
		else
			sb->dev_roles[i] = cpu_to_le16(0xffff);
	}

	sb->sb_csum = calc_sb_1_csum(sb);
}

static unsigned long long
super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
{
	struct mdp_superblock_1 *sb;
	sector_t max_sectors;
	if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
		return 0; /* component must fit device */
	if (rdev->sb_start < rdev->data_offset) {
		/* minor versions 1 and 2; superblock before data */
		max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
		max_sectors -= rdev->data_offset;
		if (!num_sectors || num_sectors > max_sectors)
			num_sectors = max_sectors;
	} else if (rdev->mddev->bitmap_info.offset) {
		/* minor version 0 with bitmap we can't move */
		return 0;
	} else {
		/* minor version 0; superblock after data */
		sector_t sb_start;
		sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
		sb_start &= ~(sector_t)(4*2 - 1);
		max_sectors = rdev->sectors + sb_start - rdev->sb_start;
		if (!num_sectors || num_sectors > max_sectors)
			num_sectors = max_sectors;
		rdev->sb_start = sb_start;
	}
	sb = (struct mdp_superblock_1 *) page_address(rdev->sb_page);
	sb->data_size = cpu_to_le64(num_sectors);
	sb->super_offset = rdev->sb_start;
	sb->sb_csum = calc_sb_1_csum(sb);
	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
		       rdev->sb_page);
	md_super_wait(rdev->mddev);
	return num_sectors;
}

static struct super_type super_types[] = {
	[0] = {
		.name	= "0.90.0",
		.owner	= THIS_MODULE,
		.load_super	    = super_90_load,
		.validate_super	    = super_90_validate,
		.sync_super	    = super_90_sync,
		.rdev_size_change   = super_90_rdev_size_change,
	},
	[1] = {
		.name	= "md-1",
		.owner	= THIS_MODULE,
		.load_super	    = super_1_load,
		.validate_super	    = super_1_validate,
		.sync_super	    = super_1_sync,
		.rdev_size_change   = super_1_rdev_size_change,
	},
};

static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
{
	mdk_rdev_t *rdev, *rdev2;

	rcu_read_lock();
	rdev_for_each_rcu(rdev, mddev1)
		rdev_for_each_rcu(rdev2, mddev2)
			if (rdev->bdev->bd_contains ==
			    rdev2->bdev->bd_contains) {
				rcu_read_unlock();
				return 1;
			}
	rcu_read_unlock();
	return 0;
}

static LIST_HEAD(pending_raid_disks);

/*
 * Try to register data integrity profile for an mddev
 *
 * This is called when an array is started and after a disk has been kicked
 * from the array. It only succeeds if all working and active component devices
 * are integrity capable with matching profiles.
 */
int md_integrity_register(mddev_t *mddev)
{
	mdk_rdev_t *rdev, *reference = NULL;

	if (list_empty(&mddev->disks))
		return 0; /* nothing to do */
	if (blk_get_integrity(mddev->gendisk))
		return 0; /* already registered */
	list_for_each_entry(rdev, &mddev->disks, same_set) {
		/* skip spares and non-functional disks */
		if (test_bit(Faulty, &rdev->flags))
			continue;
		if (rdev->raid_disk < 0)
			continue;
		/*
		 * If at least one rdev is not integrity capable, we can not
		 * enable data integrity for the md device.
		 */
		if (!bdev_get_integrity(rdev->bdev))
			return -EINVAL;
		if (!reference) {
			/* Use the first rdev as the reference */
			reference = rdev;
			continue;
		}
		/* does this rdev's profile match the reference profile? */
		if (blk_integrity_compare(reference->bdev->bd_disk,
				rdev->bdev->bd_disk) < 0)
			return -EINVAL;
	}
	/*
	 * All component devices are integrity capable and have matching
	 * profiles, register the common profile for the md device.
	 */
	if (blk_integrity_register(mddev->gendisk,
			bdev_get_integrity(reference->bdev)) != 0) {
		printk(KERN_ERR "md: failed to register integrity for %s\n",
			mdname(mddev));
		return -EINVAL;
	}
	printk(KERN_NOTICE "md: data integrity on %s enabled\n",
		mdname(mddev));
	return 0;
}
EXPORT_SYMBOL(md_integrity_register);

/* Disable data integrity if non-capable/non-matching disk is being added */
void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
{
	struct blk_integrity *bi_rdev = bdev_get_integrity(rdev->bdev);
	struct blk_integrity *bi_mddev = blk_get_integrity(mddev->gendisk);

	if (!bi_mddev) /* nothing to do */
		return;
	if (rdev->raid_disk < 0) /* skip spares */
		return;
	if (bi_rdev && blk_integrity_compare(mddev->gendisk,
					     rdev->bdev->bd_disk) >= 0)
		return;
	printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
	blk_integrity_unregister(mddev->gendisk);
}
EXPORT_SYMBOL(md_integrity_add_rdev);

static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
{
	char b[BDEVNAME_SIZE];
	struct kobject *ko;
	char *s;
	int err;

	if (rdev->mddev) {
		MD_BUG();
		return -EINVAL;
	}

	/* prevent duplicates */
	if (find_rdev(mddev, rdev->bdev->bd_dev))
		return -EEXIST;

	/* make sure rdev->sectors exceeds mddev->dev_sectors */
	if (rdev->sectors && (mddev->dev_sectors == 0 ||
			rdev->sectors < mddev->dev_sectors)) {
		if (mddev->pers) {
			/* Cannot change size, so fail
			 * If mddev->level <= 0, then we don't care
			 * about aligning sizes (e.g. linear)
			 */
			if (mddev->level > 0)
				return -ENOSPC;
		} else
			mddev->dev_sectors = rdev->sectors;
	}

	/* Verify rdev->desc_nr is unique.
	 * If it is -1, assign a free number, else
	 * check number is not in use
	 */
	if (rdev->desc_nr < 0) {
		int choice = 0;
		if (mddev->pers) choice = mddev->raid_disks;
		while (find_rdev_nr(mddev, choice))
			choice++;
		rdev->desc_nr = choice;
	} else {
		if (find_rdev_nr(mddev, rdev->desc_nr))
			return -EBUSY;
	}
	if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
		printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
		       mdname(mddev), mddev->max_disks);
		return -EBUSY;
	}
	bdevname(rdev->bdev,b);
	while ( (s=strchr(b, '/')) != NULL)
		*s = '!';

	rdev->mddev = mddev;
	printk(KERN_INFO "md: bind<%s>\n", b);

	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
		goto fail;

	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
	if (sysfs_create_link(&rdev->kobj, ko, "block"))
		/* failure here is OK */;
	rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");

	list_add_rcu(&rdev->same_set, &mddev->disks);
	bd_link_disk_holder(rdev->bdev, mddev->gendisk);

	/* May as well allow recovery to be retried once */
	mddev->recovery_disabled = 0;

	return 0;

 fail:
	printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
	       b, mdname(mddev));
	return err;
}

static void md_delayed_delete(struct work_struct *ws)
{
	mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
	kobject_del(&rdev->kobj);
	kobject_put(&rdev->kobj);
}

static void unbind_rdev_from_array(mdk_rdev_t * rdev)
{
	char b[BDEVNAME_SIZE];
	if (!rdev->mddev) {
		MD_BUG();
		return;
	}
	bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
	list_del_rcu(&rdev->same_set);
	printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
	rdev->mddev = NULL;
	sysfs_remove_link(&rdev->kobj, "block");
	sysfs_put(rdev->sysfs_state);
	rdev->sysfs_state = NULL;
	/* We need to delay this, otherwise we can deadlock when
	 * writing to 'remove' to "dev/state".  We also need
	 * to delay it due to rcu usage.
	 */
	synchronize_rcu();
	INIT_WORK(&rdev->del_work, md_delayed_delete);
	kobject_get(&rdev->kobj);
	queue_work(md_misc_wq, &rdev->del_work);
}

/*
 * prevent the device from being mounted, repartitioned or
 * otherwise reused by a RAID array (or any other kernel
 * subsystem), by bd_claiming the device.
 */
static int lock_rdev(mdk_rdev_t *rdev, dev_t dev, int shared)
{
	int err = 0;
	struct block_device *bdev;
	char b[BDEVNAME_SIZE];

	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
				 shared ? (mdk_rdev_t *)lock_rdev : rdev);
	if (IS_ERR(bdev)) {
		printk(KERN_ERR "md: could not open %s.\n",
			__bdevname(dev, b));
		return PTR_ERR(bdev);
	}
	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, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
}

void md_autodetect_dev(dev_t dev);

static void export_rdev(mdk_rdev_t * rdev)
{
	char b[BDEVNAME_SIZE];
	printk(KERN_INFO "md: export_rdev(%s)\n",
		bdevname(rdev->bdev,b));
	if (rdev->mddev)
		MD_BUG();
	free_disk_sb(rdev);
#ifndef MODULE
	if (test_bit(AutoDetected, &rdev->flags))
		md_autodetect_dev(rdev->bdev->bd_dev);
#endif
	unlock_rdev(rdev);
	kobject_put(&rdev->kobj);
}

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)
{
	mdk_rdev_t *rdev, *tmp;

	rdev_for_each(rdev, tmp, mddev) {
		if (!rdev->mddev) {
			MD_BUG();
			continue;
		}
		kick_rdev_from_array(rdev);
	}
	if (!list_empty(&mddev->disks))
		MD_BUG();
	mddev->raid_disks = 0;
	mddev->major_version = 0;
}

static void print_desc(mdp_disk_t *desc)
{
	printk(" DISK<N:%d,(%d,%d),R:%d,S:%d>\n", desc->number,
		desc->major,desc->minor,desc->raid_disk,desc->state);
}

static void print_sb_90(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_sb_1(struct mdp_superblock_1 *sb)
{
	__u8 *uuid;

	uuid = sb->set_uuid;
	printk(KERN_INFO
	       "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%pU>\n"
	       "md:    Name: \"%s\" CT:%llu\n",
		le32_to_cpu(sb->major_version),
		le32_to_cpu(sb->feature_map),
		uuid,
		sb->set_name,
		(unsigned long long)le64_to_cpu(sb->ctime)
		       & MD_SUPERBLOCK_1_TIME_SEC_MASK);

	uuid = sb->device_uuid;
	printk(KERN_INFO
	       "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
			" RO:%llu\n"
	       "md:     Dev:%08x UUID: %pU\n"
	       "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
	       "md:         (MaxDev:%u) \n",
		le32_to_cpu(sb->level),
		(unsigned long long)le64_to_cpu(sb->size),
		le32_to_cpu(sb->raid_disks),
		le32_to_cpu(sb->layout),
		le32_to_cpu(sb->chunksize),
		(unsigned long long)le64_to_cpu(sb->data_offset),
		(unsigned long long)le64_to_cpu(sb->data_size),
		(unsigned long long)le64_to_cpu(sb->super_offset),
		(unsigned long long)le64_to_cpu(sb->recovery_offset),
		le32_to_cpu(sb->dev_number),
		uuid,
		sb->devflags,
		(unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
		(unsigned long long)le64_to_cpu(sb->events),
		(unsigned long long)le64_to_cpu(sb->resync_offset),
		le32_to_cpu(sb->sb_csum),
		le32_to_cpu(sb->max_dev)
		);
}

static void print_rdev(mdk_rdev_t *rdev, int major_version)
{
	char b[BDEVNAME_SIZE];
	printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
		bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
	        test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
	        rdev->desc_nr);
	if (rdev->sb_loaded) {
		printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
		switch (major_version) {
		case 0:
			print_sb_90((mdp_super_t*)page_address(rdev->sb_page));
			break;
		case 1:
			print_sb_1((struct mdp_superblock_1 *)page_address(rdev->sb_page));
			break;
		}
	} else
		printk(KERN_INFO "md: no rdev superblock!\n");
}

static void md_print_devices(void)
{
	struct list_head *tmp;
	mdk_rdev_t *rdev;
	mddev_t *mddev;
	char b[BDEVNAME_SIZE];

	printk("\n");
	printk("md:	**********************************\n");
	printk("md:	* <COMPLETE RAID STATE PRINTOUT> *\n");
	printk("md:	**********************************\n");
	for_each_mddev(mddev, tmp) {

		if (mddev->bitmap)
			bitmap_print_sb(mddev->bitmap);
		else
			printk("%s: ", mdname(mddev));
		list_for_each_entry(rdev, &mddev->disks, same_set)
			printk("<%s>", bdevname(rdev->bdev,b));
		printk("\n");

		list_for_each_entry(rdev, &mddev->disks, same_set)
			print_rdev(rdev, mddev->major_version);
	}
	printk("md:	**********************************\n");
	printk("\n");
}


static void sync_sbs(mddev_t * mddev, int nospares)
{
	/* Update each superblock (in-memory image), but
	 * if we are allowed to, skip spares which already
	 * have the right event counter, or have one earlier
	 * (which would mean they aren't being marked as dirty
	 * with the rest of the array)
	 */
	mdk_rdev_t *rdev;
	list_for_each_entry(rdev, &mddev->disks, same_set) {
		if (rdev->sb_events == mddev->events ||
		    (nospares &&
		     rdev->raid_disk < 0 &&
		     rdev->sb_events+1 == mddev->events)) {
			/* Don't update this superblock */
			rdev->sb_loaded = 2;
		} else {
			super_types[mddev->major_version].
				sync_super(mddev, rdev);
			rdev->sb_loaded = 1;
		}
	}
}

static void md_update_sb(mddev_t * mddev, int force_change)
{
	mdk_rdev_t *rdev;
	int sync_req;
	int nospares = 0;

repeat:
	/* First make sure individual recovery_offsets are correct */
	list_for_each_entry(rdev, &mddev->disks, same_set) {
		if (rdev->raid_disk >= 0 &&
		    mddev->delta_disks >= 0 &&
		    !test_bit(In_sync, &rdev->flags) &&
		    mddev->curr_resync_completed > rdev->recovery_offset)
				rdev->recovery_offset = mddev->curr_resync_completed;

	}	
	if (!mddev->persistent) {
		clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
		clear_bit(MD_CHANGE_DEVS, &mddev->flags);
		if (!mddev->external)
			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
		wake_up(&mddev->sb_wait);
		return;
	}

	spin_lock_irq(&mddev->write_lock);

	mddev->utime = get_seconds();

	if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
		force_change = 1;
	if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
		/* just a clean<-> dirty transition, possibly leave spares alone,
		 * though if events isn't the right even/odd, we will have to do
		 * spares after all
		 */
		nospares = 1;
	if (force_change)
		nospares = 0;
	if (mddev->degraded)
		/* If the array is degraded, then skipping spares is both
		 * dangerous and fairly pointless.
		 * Dangerous because a device that was removed from the array
		 * might have a event_count that still looks up-to-date,
		 * so it can be re-added without a resync.
		 * Pointless because if there are any spares to skip,
		 * then a recovery will happen and soon that array won't
		 * be degraded any more and the spare can go back to sleep then.
		 */
		nospares = 0;

	sync_req = mddev->in_sync;

	/* If this is just a dirty<->clean transition, and the array is clean
	 * and 'events' is odd, we can roll back to the previous clean state */
	if (nospares
	    && (mddev->in_sync && mddev->recovery_cp == MaxSector)
	    && mddev->can_decrease_events
	    && mddev->events != 1) {
		mddev->events--;
		mddev->can_decrease_events = 0;
	} else {
		/* otherwise we have to go forward and ... */
		mddev->events ++;
		mddev->can_decrease_events = nospares;
	}

	if (!mddev->events) {
		/*
		 * 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->events --;
	}
	sync_sbs(mddev, nospares);
	spin_unlock_irq(&mddev->write_lock);

	dprintk(KERN_INFO 
		"md: updating %s RAID superblock on device (in sync %d)\n",
		mdname(mddev),mddev->in_sync);

	bitmap_update_sb(mddev->bitmap);
	list_for_each_entry(rdev, &mddev->disks, same_set) {
		char b[BDEVNAME_SIZE];
		dprintk(KERN_INFO "md: ");
		if (rdev->sb_loaded != 1)
			continue; /* no noise on spare devices */
		if (test_bit(Faulty, &rdev->flags))
			dprintk("(skipping faulty ");

		dprintk("%s ", bdevname(rdev->bdev,b));
		if (!test_bit(Faulty, &rdev->flags)) {
			md_super_write(mddev,rdev,
				       rdev->sb_start, rdev->sb_size,
				       rdev->sb_page);
			dprintk(KERN_INFO "(write) %s's sb offset: %llu\n",
				bdevname(rdev->bdev,b),
				(unsigned long long)rdev->sb_start);
			rdev->sb_events = mddev->events;

		} else
			dprintk(")\n");
		if (mddev->level == LEVEL_MULTIPATH)
			/* only need to write one superblock... */
			break;
	}
	md_super_wait(mddev);
	/* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */

	spin_lock_irq(&mddev->write_lock);
	if (mddev->in_sync != sync_req ||
	    test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
		/* have to write it out again */
		spin_unlock_irq(&mddev->write_lock);
		goto repeat;
	}
	clear_bit(MD_CHANGE_PENDING, &mddev->flags);
	spin_unlock_irq(&mddev->write_lock);
	wake_up(&mddev->sb_wait);
	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
		sysfs_notify(&mddev->kobj, NULL, "sync_completed");

}

/* words written to sysfs files may, or may not, be \n terminated.
 * We want to accept with case. For this we use cmd_match.
 */
static int cmd_match(const char *cmd, const char *str)
{
	/* See if cmd, written into a sysfs file, matches
	 * str.  They must either be the same, or cmd can
	 * have a trailing newline
	 */
	while (*cmd && *str && *cmd == *str) {
		cmd++;
		str++;
	}
	if (*cmd == '\n')
		cmd++;
	if (*str || *cmd)
		return 0;
	return 1;
}

struct rdev_sysfs_entry {
	struct attribute attr;
	ssize_t (*show)(mdk_rdev_t *, char *);
	ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
};

static ssize_t
state_show(mdk_rdev_t *rdev, char *page)
{
	char *sep = "";
	size_t len = 0;

	if (test_bit(Faulty, &rdev->flags)) {
		len+= sprintf(page+len, "%sfaulty",sep);
		sep = ",";
	}
	if (test_bit(In_sync, &rdev->flags)) {
		len += sprintf(page+len, "%sin_sync",sep);
		sep = ",";
	}
	if (test_bit(WriteMostly, &rdev->flags)) {
		len += sprintf(page+len, "%swrite_mostly",sep);
		sep = ",";
	}
	if (test_bit(Blocked, &rdev->flags)) {
		len += sprintf(page+len, "%sblocked", sep);
		sep = ",";
	}
	if (!test_bit(Faulty, &rdev->flags) &&
	    !test_bit(In_sync, &rdev->flags)) {
		len += sprintf(page+len, "%sspare", sep);
		sep = ",";
	}
	return len+sprintf(page+len, "\n");
}

static ssize_t
state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
{
	/* can write
	 *  faulty  - simulates and error
	 *  remove  - disconnects the device
	 *  writemostly - sets write_mostly
	 *  -writemostly - clears write_mostly
	 *  blocked - sets the Blocked flag
	 *  -blocked - clears the Blocked flag
	 *  insync - sets Insync providing device isn't active
	 */
	int err = -EINVAL;
	if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
		md_error(rdev->mddev, rdev);
		err = 0;
	} else if (cmd_match(buf, "remove")) {
		if (rdev->raid_disk >= 0)
			err = -EBUSY;
		else {
			mddev_t *mddev = rdev->mddev;
			kick_rdev_from_array(rdev);
			if (mddev->pers)
				md_update_sb(mddev, 1);
			md_new_event(mddev);
			err = 0;
		}
	} else if (cmd_match(buf, "writemostly")) {
		set_bit(WriteMostly, &rdev->flags);
		err = 0;
	} else if (cmd_match(buf, "-writemostly")) {
		clear_bit(WriteMostly, &rdev->flags);
		err = 0;
	} else if (cmd_match(buf, "blocked")) {
		set_bit(Blocked, &rdev->flags);
		err = 0;
	} else if (cmd_match(buf, "-blocked")) {
		clear_bit(Blocked, &rdev->flags);
		wake_up(&rdev->blocked_wait);
		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
		md_wakeup_thread(rdev->mddev->thread);

		err = 0;
	} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
		set_bit(In_sync, &rdev->flags);
		err = 0;
	}
	if (!err)
		sysfs_notify_dirent_safe(rdev->sysfs_state);
	return err ? err : len;
}
static struct rdev_sysfs_entry rdev_state =
__ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);

static ssize_t
errors_show(mdk_rdev_t *rdev, char *page)
{
	return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
}

static ssize_t
errors_store(mdk_rdev_t *rdev, const char *buf, size_t len)
{
	char *e;
	unsigned long n = simple_strtoul(buf, &e, 10);
	if (*buf && (*e == 0 || *e == '\n')) {
		atomic_set(&rdev->corrected_errors, n);
		return len;
	}
	return -EINVAL;
}
static struct rdev_sysfs_entry rdev_errors =
__ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);

static ssize_t
slot_show(mdk_rdev_t *rdev, char *page)
{
	if (rdev->raid_disk < 0)
		return sprintf(page, "none\n");
	else
		return sprintf(page, "%d\n", rdev->raid_disk);
}

static ssize_t
slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
{
	char *e;
	int err;
	char nm[20];
	int slot = simple_strtoul(buf, &e, 10);
	if (strncmp(buf, "none", 4)==0)
		slot = -1;
	else if (e==buf || (*e && *e!= '\n'))
		return -EINVAL;
	if (rdev->mddev->pers && slot == -1) {
		/* Setting 'slot' on an active array requires also
		 * updating the 'rd%d' link, and communicating
		 * with the personality with ->hot_*_disk.
		 * For now we only support removing
		 * failed/spare devices.  This normally happens automatically,
		 * but not when the metadata is externally managed.
		 */
		if (rdev->raid_disk == -1)
			return -EEXIST;
		/* personality does all needed checks */
		if (rdev->mddev->pers->hot_add_disk == NULL)
			return -EINVAL;
		err = rdev->mddev->pers->
			hot_remove_disk(rdev->mddev, rdev->raid_disk);
		if (err)
			return err;
		sprintf(nm, "rd%d", rdev->raid_disk);
		sysfs_remove_link(&rdev->mddev->kobj, nm);
		rdev->raid_disk = -1;
		set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
		md_wakeup_thread(rdev->mddev->thread);
	} else if (rdev->mddev->pers) {
		mdk_rdev_t *rdev2;
		/* Activating a spare .. or possibly reactivating
		 * if we ever get bitmaps working here.
		 */

		if (rdev->raid_disk != -1)
			return -EBUSY;

		if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
			return -EBUSY;

		if (rdev->mddev->pers->hot_add_disk == NULL)
			return -EINVAL;

		list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
			if (rdev2->raid_disk == slot)
				return -EEXIST;

		if (slot >= rdev->mddev->raid_disks &&
		    slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
			return -ENOSPC;

		rdev->raid_disk = slot;
		if (test_bit(In_sync, &rdev->flags))
			rdev->saved_raid_disk = slot;
		else
			rdev->saved_raid_disk = -1;
		err = rdev->mddev->pers->
			hot_add_disk(rdev->mddev, rdev);
		if (err) {
			rdev->raid_disk = -1;
			return err;
		} else
			sysfs_notify_dirent_safe(rdev->sysfs_state);
		sprintf(nm, "rd%d", rdev->raid_disk);
		if (sysfs_create_link(&rdev->mddev->kobj, &rdev->kobj, nm))
			/* failure here is OK */;
		/* don't wakeup anyone, leave that to userspace. */
	} else {
		if (slot >= rdev->mddev->raid_disks &&
		    slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
			return -ENOSPC;
		rdev->raid_disk = slot;
		/* assume it is working */
		clear_bit(Faulty, &rdev->flags);
		clear_bit(WriteMostly, &rdev->flags);
		set_bit(In_sync, &rdev->flags);
		sysfs_notify_dirent_safe(rdev->sysfs_state);
	}
	return len;
}


static struct rdev_sysfs_entry rdev_slot =
__ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);

static ssize_t
offset_show(mdk_rdev_t *rdev, char *page)
{
	return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
}

static ssize_t
offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
{
	char *e;
	unsigned long long offset = simple_strtoull(buf, &e, 10);
	if (e==buf || (*e && *e != '\n'))
		return -EINVAL;
	if (rdev->mddev->pers && rdev->raid_disk >= 0)
		return -EBUSY;
	if (rdev->sectors && rdev->mddev->external)
		/* Must set offset before size, so overlap checks
		 * can be sane */
		return -EBUSY;
	rdev->data_offset = offset;
	return len;
}

static struct rdev_sysfs_entry rdev_offset =
__ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);

static ssize_t
rdev_size_show(mdk_rdev_t *rdev, char *page)
{
	return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
}

static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
{
	/* check if two start/length pairs overlap */
	if (s1+l1 <= s2)
		return 0;
	if (s2+l2 <= s1)
		return 0;
	return 1;
}

static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
{
	unsigned long long blocks;
	sector_t new;

	if (strict_strtoull(buf, 10, &blocks) < 0)
		return -EINVAL;

	if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
		return -EINVAL; /* sector conversion overflow */

	new = blocks * 2;
	if (new != blocks * 2)
		return -EINVAL; /* unsigned long long to sector_t overflow */

	*sectors = new;
	return 0;
}

static ssize_t
rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
{
	mddev_t *my_mddev = rdev->mddev;
	sector_t oldsectors = rdev->sectors;
	sector_t sectors;

	if (strict_blocks_to_sectors(buf, &sectors) < 0)
		return -EINVAL;
	if (my_mddev->pers && rdev->raid_disk >= 0) {
		if (my_mddev->persistent) {
			sectors = super_types[my_mddev->major_version].
				rdev_size_change(rdev, sectors);
			if (!sectors)
				return -EBUSY;
		} else if (!sectors)
			sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
				rdev->data_offset;
	}
	if (sectors < my_mddev->dev_sectors)
		return -EINVAL; /* component must fit device */

	rdev->sectors = sectors;
	if (sectors > oldsectors && my_mddev->external) {
		/* need to check that all other rdevs with the same ->bdev
		 * do not overlap.  We need to unlock the mddev to avoid
		 * a deadlock.  We have already changed rdev->sectors, and if
		 * we have to change it back, we will have the lock again.
		 */
		mddev_t *mddev;
		int overlap = 0;
		struct list_head *tmp;

		mddev_unlock(my_mddev);
		for_each_mddev(mddev, tmp) {
			mdk_rdev_t *rdev2;

			mddev_lock(mddev);
			list_for_each_entry(rdev2, &mddev->disks, same_set)
				if (rdev->bdev == rdev2->bdev &&
				    rdev != rdev2 &&
				    overlaps(rdev->data_offset, rdev->sectors,
					     rdev2->data_offset,
					     rdev2->sectors)) {
					overlap = 1;
					break;
				}
			mddev_unlock(mddev);
			if (overlap) {
				mddev_put(mddev);
				break;
			}
		}
		mddev_lock(my_mddev);
		if (overlap) {
			/* Someone else could have slipped in a size
			 * change here, but doing so is just silly.
			 * We put oldsectors back because we *know* it is
			 * safe, and trust userspace not to race with
			 * itself
			 */
			rdev->sectors = oldsectors;
			return -EBUSY;
		}
	}
	return len;
}

static struct rdev_sysfs_entry rdev_size =
__ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);


static ssize_t recovery_start_show(mdk_rdev_t *rdev, char *page)
{
	unsigned long long recovery_start = rdev->recovery_offset;

	if (test_bit(In_sync, &rdev->flags) ||
	    recovery_start == MaxSector)
		return sprintf(page, "none\n");

	return sprintf(page, "%llu\n", recovery_start);
}

static ssize_t recovery_start_store(mdk_rdev_t *rdev, const char *buf, size_t len)
{
	unsigned long long recovery_start;

	if (cmd_match(buf, "none"))
		recovery_start = MaxSector;
	else if (strict_strtoull(buf, 10, &recovery_start))
		return -EINVAL;

	if (rdev->mddev->pers &&
	    rdev->raid_disk >= 0)
		return -EBUSY;

	rdev->recovery_offset = recovery_start;
	if (recovery_start == MaxSector)
		set_bit(In_sync, &rdev->flags);
	else
		clear_bit(In_sync, &rdev->flags);
	return len;
}

static struct rdev_sysfs_entry rdev_recovery_start =
__ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);

static struct attribute *rdev_default_attrs[] = {
	&rdev_state.attr,
	&rdev_errors.attr,
	&rdev_slot.attr,
	&rdev_offset.attr,
	&rdev_size.attr,
	&rdev_recovery_start.attr,
	NULL,
};
static ssize_t
rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
{
	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
	mddev_t *mddev = rdev->mddev;
	ssize_t rv;

	if (!entry->show)
		return -EIO;

	rv = mddev ? mddev_lock(mddev) : -EBUSY;
	if (!rv) {
		if (rdev->mddev == NULL)
			rv = -EBUSY;
		else
			rv = entry->show(rdev, page);
		mddev_unlock(mddev);
	}
	return rv;
}

static ssize_t
rdev_attr_store(struct kobject *kobj, struct attribute *attr,
	      const char *page, size_t length)
{
	struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
	mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
	ssize_t rv;
	mddev_t *mddev = rdev->mddev;

	if (!entry->store)
		return -EIO;
	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;
	rv = mddev ? mddev_lock(mddev): -EBUSY;
	if (!rv) {
		if (rdev->mddev == NULL)
			rv = -EBUSY;
		else
			rv = entry->store(rdev, page, length);
		mddev_unlock(mddev);
	}
	return rv;
}

static void rdev_free(struct kobject *ko)
{
	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
	kfree(rdev);
}
static const struct sysfs_ops rdev_sysfs_ops = {
	.show		= rdev_attr_show,
	.store		= rdev_attr_store,
};
static struct kobj_type rdev_ktype = {
	.release	= rdev_free,
	.sysfs_ops	= &rdev_sysfs_ops,
	.default_attrs	= rdev_default_attrs,
};

void md_rdev_init(mdk_rdev_t *rdev)
{
	rdev->desc_nr = -1;
	rdev->saved_raid_disk = -1;
	rdev->raid_disk = -1;
	rdev->flags = 0;
	rdev->data_offset = 0;
	rdev->sb_events = 0;
	rdev->last_read_error.tv_sec  = 0;
	rdev->last_read_error.tv_nsec = 0;
	atomic_set(&rdev->nr_pending, 0);
	atomic_set(&rdev->read_errors, 0);
	atomic_set(&rdev->corrected_errors, 0);

	INIT_LIST_HEAD(&rdev->same_set);
	init_waitqueue_head(&rdev->blocked_wait);
}
EXPORT_SYMBOL_GPL(md_rdev_init);
/*
 * Import a device. If 'super_format' >= 0, then sanity check the superblock
 *
 * mark the device faulty if:
 *
 *   - the device is nonexistent (zero size)
 *   - the device has no valid superblock
 *
 * a faulty rdev _never_ has rdev->sb set.
 */
static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_minor)
{
	char b[BDEVNAME_SIZE];
	int err;
	mdk_rdev_t *rdev;
	sector_t size;

	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
	if (!rdev) {
		printk(KERN_ERR "md: could not alloc mem for new device!\n");
		return ERR_PTR(-ENOMEM);
	}

	md_rdev_init(rdev);
	if ((err = alloc_disk_sb(rdev)))
		goto abort_free;

	err = lock_rdev(rdev, newdev, super_format == -2);
	if (err)
		goto abort_free;

	kobject_init(&rdev->kobj, &rdev_ktype);

	size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
	if (!size) {
		printk(KERN_WARNING 
			"md: %s has zero or unknown size, marking faulty!\n",
			bdevname(rdev->bdev,b));
		err = -EINVAL;
		goto abort_free;
	}

	if (super_format >= 0) {
		err = super_types[super_format].
			load_super(rdev, NULL, super_minor);
		if (err == -EINVAL) {
			printk(KERN_WARNING
				"md: %s does not have a valid v%d.%d "
			       "superblock, not importing!\n",
				bdevname(rdev->bdev,b),
			       super_format, super_minor);
			goto abort_free;
		}
		if (err < 0) {
			printk(KERN_WARNING 
				"md: could not read %s's sb, not importing!\n",
				bdevname(rdev->bdev,b));
			goto abort_free;
		}
	}

	return rdev;

abort_free:
	if (rdev->sb_page) {
		if (rdev->bdev)
			unlock_rdev(rdev);
		free_disk_sb(rdev);
	}
	kfree(rdev);
	return ERR_PTR(err);
}

/*
 * Check a full RAID array for plausibility
 */


static void analyze_sbs(mddev_t * mddev)
{
	int i;
	mdk_rdev_t *rdev, *freshest, *tmp;
	char b[BDEVNAME_SIZE];

	freshest = NULL;
	rdev_for_each(rdev, tmp, mddev)
		switch (super_types[mddev->major_version].
			load_super(rdev, freshest, mddev->minor_version)) {
		case 1:
			freshest = rdev;
			break;
		case 0:
			break;
		default:
			printk( KERN_ERR \
				"md: fatal superblock inconsistency in %s"
				" -- removing from array\n", 
				bdevname(rdev->bdev,b));
			kick_rdev_from_array(rdev);
		}


	super_types[mddev->major_version].
		validate_super(mddev, freshest);

	i = 0;
	rdev_for_each(rdev, tmp, mddev) {
		if (mddev->max_disks &&
		    (rdev->desc_nr >= mddev->max_disks ||
		     i > mddev->max_disks)) {
			printk(KERN_WARNING
			       "md: %s: %s: only %d devices permitted\n",
			       mdname(mddev), bdevname(rdev->bdev, b),
			       mddev->max_disks);
			kick_rdev_from_array(rdev);
			continue;
		}
		if (rdev != freshest)
			if (super_types[mddev->major_version].
			    validate_super(mddev, rdev)) {
				printk(KERN_WARNING "md: kicking non-fresh %s"
					" from array!\n",
					bdevname(rdev->bdev,b));
				kick_rdev_from_array(rdev);
				continue;
			}
		if (mddev->level == LEVEL_MULTIPATH) {
			rdev->desc_nr = i++;
			rdev->raid_disk = rdev->desc_nr;
			set_bit(In_sync, &rdev->flags);
		} else if (rdev->raid_disk >= (mddev->raid_disks - min(0, mddev->delta_disks))) {
			rdev->raid_disk = -1;
			clear_bit(In_sync, &rdev->flags);
		}
	}
}

/* Read a fixed-point number.
 * Numbers in sysfs attributes should be in "standard" units where
 * possible, so time should be in seconds.
 * However we internally use a a much smaller unit such as 
 * milliseconds or jiffies.
 * This function takes a decimal number with a possible fractional
 * component, and produces an integer which is the result of
 * multiplying that number by 10^'scale'.
 * all without any floating-point arithmetic.
 */
int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
{
	unsigned long result = 0;
	long decimals = -1;
	while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
		if (*cp == '.')
			decimals = 0;
		else if (decimals < scale) {
			unsigned int value;
			value = *cp - '0';
			result = result * 10 + value;
			if (decimals >= 0)
				decimals++;
		}
		cp++;
	}
	if (*cp == '\n')
		cp++;
	if (*cp)
		return -EINVAL;
	if (decimals < 0)
		decimals = 0;
	while (decimals < scale) {
		result *= 10;
		decimals ++;
	}
	*res = result;
	return 0;
}


static void md_safemode_timeout(unsigned long data);

static ssize_t
safe_delay_show(mddev_t *mddev, char *page)
{
	int msec = (mddev->safemode_delay*1000)/HZ;
	return sprintf(page, "%d.%03d\n", msec/1000, msec%1000);
}
static ssize_t
safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)
{
	unsigned long msec;

	if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
		return -EINVAL;
	if (msec == 0)
		mddev->safemode_delay = 0;
	else {
		unsigned long old_delay = mddev->safemode_delay;
		mddev->safemode_delay = (msec*HZ)/1000;
		if (mddev->safemode_delay == 0)
			mddev->safemode_delay = 1;
		if (mddev->safemode_delay < old_delay)
			md_safemode_timeout((unsigned long)mddev);
	}
	return len;
}
static struct md_sysfs_entry md_safe_delay =
__ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);

static ssize_t
level_show(mddev_t *mddev, char *page)
{
	struct mdk_personality *p = mddev->pers;
	if (p)
		return sprintf(page, "%s\n", p->name);
	else if (mddev->clevel[0])
		return sprintf(page, "%s\n", mddev->clevel);
	else if (mddev->level != LEVEL_NONE)
		return sprintf(page, "%d\n", mddev->level);
	else
		return 0;
}

static ssize_t
level_store(mddev_t *mddev, const char *buf, size_t len)
{
	char clevel[16];
	ssize_t rv = len;
	struct mdk_personality *pers;
	long level;
	void *priv;
	mdk_rdev_t *rdev;

	if (mddev->pers == NULL) {
		if (len == 0)
			return 0;
		if (len >= sizeof(mddev->clevel))
			return -ENOSPC;
		strncpy(mddev->clevel, buf, len);
		if (mddev->clevel[len-1] == '\n')
			len--;
		mddev->clevel[len] = 0;
		mddev->level = LEVEL_NONE;
		return rv;
	}

	/* request to change the personality.  Need to ensure:
	 *  - array is not engaged in resync/recovery/reshape
	 *  - old personality can be suspended
	 *  - new personality will access other array.
	 */

	if (mddev->sync_thread ||
	    mddev->reshape_position != MaxSector ||
	    mddev->sysfs_active)
		return -EBUSY;

	if (!mddev->pers->quiesce) {
		printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
		       mdname(mddev), mddev->pers->name);
		return -EINVAL;
	}

	/* Now find the new personality */
	if (len == 0 || len >= sizeof(clevel))
		return -EINVAL;
	strncpy(clevel, buf, len);
	if (clevel[len-1] == '\n')
		len--;
	clevel[len] = 0;
	if (strict_strtol(clevel, 10, &level))
		level = LEVEL_NONE;

	if (request_module("md-%s", clevel) != 0)
		request_module("md-level-%s", clevel);
	spin_lock(&pers_lock);
	pers = find_pers(level, clevel);
	if (!pers || !try_module_get(pers->owner)) {
		spin_unlock(&pers_lock);
		printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
		return -EINVAL;
	}
	spin_unlock(&pers_lock);

	if (pers == mddev->pers) {
		/* Nothing to do! */
		module_put(pers->owner);
		return rv;
	}
	if (!pers->takeover) {
		module_put(pers->owner);
		printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
		       mdname(mddev), clevel);
		return -EINVAL;
	}

	list_for_each_entry(rdev, &mddev->disks, same_set)
		rdev->new_raid_disk = rdev->raid_disk;

	/* ->takeover must set new_* and/or delta_disks
	 * if it succeeds, and may set them when it fails.
	 */
	priv = pers->takeover(mddev);
	if (IS_ERR(priv)) {
		mddev->new_level = mddev->level;
		mddev->new_layout = mddev->layout;
		mddev->new_chunk_sectors = mddev->chunk_sectors;
		mddev->raid_disks -= mddev->delta_disks;
		mddev->delta_disks = 0;
		module_put(pers->owner);
		printk(KERN_WARNING "md: %s: %s would not accept array\n",
		       mdname(mddev), clevel);
		return PTR_ERR(priv);
	}

	/* Looks like we have a winner */
	mddev_suspend(mddev);
	mddev->pers->stop(mddev);
	
	if (mddev->pers->sync_request == NULL &&
	    pers->sync_request != NULL) {
		/* need to add the md_redundancy_group */
		if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
			printk(KERN_WARNING
			       "md: cannot register extra attributes for %s\n",
			       mdname(mddev));
		mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, NULL, "sync_action");
	}		
	if (mddev->pers->sync_request != NULL &&
	    pers->sync_request == NULL) {
		/* need to remove the md_redundancy_group */
		if (mddev->to_remove == NULL)
			mddev->to_remove = &md_redundancy_group;
	}

	if (mddev->pers->sync_request == NULL &&
	    mddev->external) {
		/* We are converting from a no-redundancy array
		 * to a redundancy array and metadata is managed
		 * externally so we need to be sure that writes
		 * won't block due to a need to transition
		 *      clean->dirty
		 * until external management is started.
		 */
		mddev->in_sync = 0;
		mddev->safemode_delay = 0;
		mddev->safemode = 0;
	}

	list_for_each_entry(rdev, &mddev->disks, same_set) {
		char nm[20];
		if (rdev->raid_disk < 0)
			continue;
		if (rdev->new_raid_disk >= mddev->raid_disks)
			rdev->new_raid_disk = -1;
		if (rdev->new_raid_disk == rdev->raid_disk)
			continue;
		sprintf(nm, "rd%d", rdev->raid_disk);
		sysfs_remove_link(&mddev->kobj, nm);
	}
	list_for_each_entry(rdev, &mddev->disks, same_set) {
		if (rdev->raid_disk < 0)
			continue;
		if (rdev->new_raid_disk == rdev->raid_disk)
			continue;
		rdev->raid_disk = rdev->new_raid_disk;
		if (rdev->raid_disk < 0)
			clear_bit(In_sync, &rdev->flags);
		else {
			char nm[20];
			sprintf(nm, "rd%d", rdev->raid_disk);
			if(sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
				printk("md: cannot register %s for %s after level change\n",
				       nm, mdname(mddev));
		}
	}

	module_put(mddev->pers->owner);
	mddev->pers = pers;
	mddev->private = priv;
	strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
	mddev->level = mddev->new_level;
	mddev->layout = mddev->new_layout;
	mddev->chunk_sectors = mddev->new_chunk_sectors;
	mddev->delta_disks = 0;
	if (mddev->pers->sync_request == NULL) {
		/* this is now an array without redundancy, so
		 * it must always be in_sync
		 */
		mddev->in_sync = 1;
		del_timer_sync(&mddev->safemode_timer);
	}
	pers->run(mddev);
	mddev_resume(mddev);
	set_bit(MD_CHANGE_DEVS, &mddev->flags);
	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
	md_wakeup_thread(mddev->thread);
	sysfs_notify(&mddev->kobj, NULL, "level");
	md_new_event(mddev);
	return rv;
}

static struct md_sysfs_entry md_level =
__ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);


static ssize_t
layout_show(mddev_t *mddev, char *page)
{
	/* just a number, not meaningful for all levels */
	if (mddev->reshape_position != MaxSector &&
	    mddev->layout != mddev->new_layout)
		return sprintf(page, "%d (%d)\n",
			       mddev->new_layout, mddev->layout);
	return sprintf(page, "%d\n", mddev->layout);
}

static ssize_t
layout_store(mddev_t *mddev, const char *buf, size_t len)
{
	char *e;
	unsigned long n = simple_strtoul(buf, &e, 10);

	if (!*buf || (*e && *e != '\n'))
		return -EINVAL;

	if (mddev->pers) {
		int err;
		if (mddev->pers->check_reshape == NULL)
			return -EBUSY;
		mddev->new_layout = n;
		err = mddev->pers->check_reshape(mddev);
		if (err) {
			mddev->new_layout = mddev->layout;
			return err;
		}
	} else {
		mddev->new_layout = n;
		if (mddev->reshape_position == MaxSector)
			mddev->layout = n;
	}
	return len;
}
static struct md_sysfs_entry md_layout =
__ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);


static ssize_t
raid_disks_show(mddev_t *mddev, char *page)
{
	if (mddev->raid_disks == 0)
		return 0;
	if (mddev->reshape_position != MaxSector &&
	    mddev->delta_disks != 0)
		return sprintf(page, "%d (%d)\n", mddev->raid_disks,
			       mddev->raid_disks - mddev->delta_disks);
	return sprintf(page, "%d\n", mddev->raid_disks);
}

static int update_raid_disks(mddev_t *mddev, int raid_disks);

static ssize_t
raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
{
	char *e;
	int rv = 0;
	unsigned long n = simple_strtoul(buf, &e, 10);

	if (!*buf || (*e && *e != '\n'))
		return -EINVAL;

	if (mddev->pers)
		rv = update_raid_disks(mddev, n);
	else if (mddev->reshape_position != MaxSector) {
		int olddisks = mddev->raid_disks - mddev->delta_disks;
		mddev->delta_disks = n - olddisks;
		mddev->raid_disks = n;
	} else
		mddev->raid_disks = n;
	return rv ? rv : len;
}
static struct md_sysfs_entry md_raid_disks =
__ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);

static ssize_t
chunk_size_show(mddev_t *mddev, char *page)
{
	if (mddev->reshape_position != MaxSector &&
	    mddev->chunk_sectors != mddev->new_chunk_sectors)
		return sprintf(page, "%d (%d)\n",
			       mddev->new_chunk_sectors << 9,
			       mddev->chunk_sectors << 9);
	return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
}

static ssize_t
chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
{
	char *e;
	unsigned long n = simple_strtoul(buf, &e, 10);

	if (!*buf || (*e && *e != '\n'))
		return -EINVAL;

	if (mddev->pers) {
		int err;
		if (mddev->pers->check_reshape == NULL)
			return -EBUSY;
		mddev->new_chunk_sectors = n >> 9;
		err = mddev->pers->check_reshape(mddev);
		if (err) {
			mddev->new_chunk_sectors = mddev->chunk_sectors;
			return err;
		}
	} else {
		mddev->new_chunk_sectors = n >> 9;
		if (mddev->reshape_position == MaxSector)
			mddev->chunk_sectors = n >> 9;
	}
	return len;
}
static struct md_sysfs_entry md_chunk_size =
__ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);

static ssize_t
resync_start_show(mddev_t *mddev, char *page)
{
	if (mddev->recovery_cp == MaxSector)
		return sprintf(page, "none\n");
	return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
}

static ssize_t
resync_start_store(mddev_t *mddev, const char *buf, size_t len)
{
	char *e;
	unsigned long long n = simple_strtoull(buf, &e, 10);

	if (mddev->pers)
		return -EBUSY;
	if (cmd_match(buf, "none"))
		n = MaxSector;
	else if (!*buf || (*e && *e != '\n'))
		return -EINVAL;

	mddev->recovery_cp = n;
	return len;
}
static struct md_sysfs_entry md_resync_start =
__ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);

/*
 * The array state can be:
 *
 * clear
 *     No devices, no size, no level
 *     Equivalent to STOP_ARRAY ioctl
 * inactive
 *     May have some settings, but array is not active
 *        all IO results in error
 *     When written, doesn't tear down array, but just stops it
 * suspended (not supported yet)
 *     All IO requests will block. The array can be reconfigured.
 *     Writing this, if accepted, will block until array is quiescent
 * readonly
 *     no resync can happen.  no superblocks get written.
 *     write requests fail
 * read-auto
 *     like readonly, but behaves like 'clean' on a write request.
 *
 * clean - no pending writes, but otherwise active.
 *     When written to inactive array, starts without resync
 *     If a write request arrives then
 *       if metadata is known, mark 'dirty' and switch to 'active'.
 *       if not known, block and switch to write-pending
 *     If written to an active array that has pending writes, then fails.
 * active
 *     fully active: IO and resync can be happening.
 *     When written to inactive array, starts with resync
 *
 * write-pending
 *     clean, but writes are blocked waiting for 'active' to be written.
 *
 * active-idle
 *     like active, but no writes have been seen for a while (100msec).
 *
 */
enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
		   write_pending, active_idle, bad_word};
static char *array_states[] = {
	"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
	"write-pending", "active-idle", NULL };

static int match_word(const char *word, char **list)
{
	int n;
	for (n=0; list[n]; n++)
		if (cmd_match(word, list[n]))
			break;
	return n;
}

static ssize_t
array_state_show(mddev_t *mddev, char *page)
{
	enum array_state st = inactive;

	if (mddev->pers)
		switch(mddev->ro) {
		case 1:
			st = readonly;
			break;
		case 2:
			st = read_auto;
			break;
		case 0:
			if (mddev->in_sync)
				st = clean;
			else if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
				st = write_pending;
			else if (mddev->safemode)
				st = active_idle;
			else
				st = active;
		}
	else {
		if (list_empty(&mddev->disks) &&
		    mddev->raid_disks == 0 &&
		    mddev->dev_sectors == 0)
			st = clear;
		else
			st = inactive;
	}
	return sprintf(page, "%s\n", array_states[st]);
}

static int do_md_stop(mddev_t * mddev, int ro, int is_open);
static int md_set_readonly(mddev_t * mddev, int is_open);
static int do_md_run(mddev_t * mddev);
static int restart_array(mddev_t *mddev);

static ssize_t
array_state_store(mddev_t *mddev, const char *buf, size_t len)
{
	int err = -EINVAL;
	enum array_state st = match_word(buf, array_states);
	switch(st) {
	case bad_word:
		break;
	case clear:
		/* stopping an active array */
		if (atomic_read(&mddev->openers) > 0)
			return -EBUSY;
		err = do_md_stop(mddev, 0, 0);
		break;
	case inactive:
		/* stopping an active array */
		if (mddev->pers) {
			if (atomic_read(&mddev->openers) > 0)
				return -EBUSY;
			err = do_md_stop(mddev, 2, 0);
		} else
			err = 0; /* already inactive */
		break;
	case suspended:
		break; /* not supported yet */
	case readonly:
		if (mddev->pers)
			err = md_set_readonly(mddev, 0);
		else {
			mddev->ro = 1;
			set_disk_ro(mddev->gendisk, 1);
			err = do_md_run(mddev);
		}
		break;
	case read_auto:
		if (mddev->pers) {
			if (mddev->ro == 0)
				err = md_set_readonly(mddev, 0);
			else if (mddev->ro == 1)
				err = restart_array(mddev);
			if (err == 0) {
				mddev->ro = 2;
				set_disk_ro(mddev->gendisk, 0);
			}
		} else {
			mddev->ro = 2;
			err = do_md_run(mddev);
		}
		break;
	case clean:
		if (mddev->pers) {
			restart_array(mddev);
			spin_lock_irq(&mddev->write_lock);
			if (atomic_read(&mddev->writes_pending) == 0) {
				if (mddev->in_sync == 0) {
					mddev->in_sync = 1;
					if (mddev->safemode == 1)
						mddev->safemode = 0;
					set_bit(MD_CHANGE_CLEAN, &mddev->flags);
				}
				err = 0;
			} else
				err = -EBUSY;
			spin_unlock_irq(&mddev->write_lock);
		} else
			err = -EINVAL;
		break;
	case active:
		if (mddev->pers) {
			restart_array(mddev);
			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
			wake_up(&mddev->sb_wait);
			err = 0;
		} else {
			mddev->ro = 0;
			set_disk_ro(mddev->gendisk, 0);
			err = do_md_run(mddev);
		}
		break;
	case write_pending:
	case active_idle:
		/* these cannot be set */
		break;
	}
	if (err)
		return err;
	else {
		sysfs_notify_dirent_safe(mddev->sysfs_state);
		return len;
	}
}
static struct md_sysfs_entry md_array_state =
__ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);

static ssize_t
max_corrected_read_errors_show(mddev_t *mddev, char *page) {
	return sprintf(page, "%d\n",
		       atomic_read(&mddev->max_corr_read_errors));
}

static ssize_t
max_corrected_read_errors_store(mddev_t *mddev, const char *buf, size_t len)
{
	char *e;
	unsigned long n = simple_strtoul(buf, &e, 10);

	if (*buf && (*e == 0 || *e == '\n')) {
		atomic_set(&mddev->max_corr_read_errors, n);
		return len;
	}
	return -EINVAL;
}
Mode	Name	Size
-rw-r--r--	00-INDEX	12186	log stats plain blame
d---------	ABI	170	log stats plain
-rw-r--r--	BUG-HUNTING	8326	log stats plain blame
-rw-r--r--	Changes	12355	log stats plain blame
-rw-r--r--	CodingStyle	29820	log stats plain blame
-rw-r--r--	DMA-API.txt	28886	log stats plain blame
-rw-r--r--	DMA-ISA-LPC.txt	5333	log stats plain blame
-rw-r--r--	DMA-attributes.txt	1376	log stats plain blame
-rw-r--r--	DMA-mapping.txt	27929	log stats plain blame
d---------	DocBook	1626	log stats plain
-rw-r--r--	HOWTO	29317	log stats plain blame
-rw-r--r--	IO-mapping.txt	8042	log stats plain blame
-rw-r--r--	IPMI.txt	27606	log stats plain blame
-rw-r--r--	IRQ-affinity.txt	2190	log stats plain blame
-rw-r--r--	IRQ.txt	962	log stats plain blame
-rw-r--r--	Intel-IOMMU.txt	3849	log stats plain blame
-rw-r--r--	Makefile	143	log stats plain blame
-rw-r--r--	ManagementStyle	13249	log stats plain blame
d---------	PCI	297	log stats plain
d---------	RCU	542	log stats plain
-rw-r--r--	SAK.txt	2918	log stats plain blame
-rw-r--r--	SELinux.txt	1041	log stats plain blame
-rw-r--r--	SM501.txt	2859	log stats plain blame
-rw-r--r--	SecurityBugs	1887	log stats plain blame
-rw-r--r--	Smack.txt	22154	log stats plain blame
-rw-r--r--	SubmitChecklist	3587	log stats plain blame
-rw-r--r--	SubmittingDrivers	6305	log stats plain blame
-rw-r--r--	SubmittingPatches	28473	log stats plain blame
-rw-r--r--	VGA-softcursor.txt	2051	log stats plain blame
d---------	accounting	293	log stats plain
d---------	acpi	128	log stats plain
d---------	aoe	301	log stats plain
-rw-r--r--	applying-patches.txt	19961	log stats plain blame
d---------	arm	664	log stats plain
-rw-r--r--	atomic_ops.txt	19503	log stats plain blame
d---------	auxdisplay	194	log stats plain
-rw-r--r--	bad_memory.txt	1113	log stats plain blame
-rw-r--r--	basic_profiling.txt	1707	log stats plain blame
-rw-r--r--	binfmt_misc.txt	6108	log stats plain blame
d---------	blackfin	209	log stats plain
d---------	block	494	log stats plain
d---------	blockdev	342	log stats plain
-rw-r--r--	braille-console.txt	1458	log stats plain blame
-rw-r--r--	bt8xxgpio.txt	4402	log stats plain blame
-rw-r--r--	btmrvl.txt	2934	log stats plain blame
-rw-r--r--	c2port.txt	2848	log stats plain blame
-rw-r--r--	cachetlb.txt	16265	log stats plain blame
d---------	cdrom	198	log stats plain
d---------	cgroups	369	log stats plain
d---------	connector	186	log stats plain
d---------	console	39	log stats plain
d---------	cpu-freq	335	log stats plain
-rw-r--r--	cpu-hotplug.txt	14935	log stats plain blame
-rw-r--r--	cpu-load.txt	3110	log stats plain blame
d---------	cpuidle	151	log stats plain
-rw-r--r--	cputopology.txt	3013	log stats plain blame
-rw-r--r--	credentials.txt	20932	log stats plain blame
d---------	cris	34	log stats plain
d---------	crypto	131	log stats plain
-rw-r--r--	dcdbas.txt	3709	log stats plain blame
-rw-r--r--	debugging-modules.txt	954	log stats plain blame
-rw-r--r--	debugging-via-ohci1394.txt	7635	log stats plain blame
-rw-r--r--	dell_rbu.txt	4973	log stats plain blame
d---------	development-process	313	log stats plain
d---------	device-mapper	478	log stats plain
-rw-r--r--	devices.txt	118144	log stats plain blame
-rw-r--r--	dmaengine.txt	42	log stats plain blame
-rw-r--r--	dontdiff	1950	log stats plain blame
d---------	driver-model	385	log stats plain
d---------	dvb	516	log stats plain
-rw-r--r--	dynamic-debug-howto.txt	8633	log stats plain blame
d---------	early-userspace	79	log stats plain
-rw-r--r--	edac.txt	21312	log stats plain blame
-rw-r--r--	eisa.txt	7293	log stats plain blame
-rw-r--r--	email-clients.txt	9261	log stats plain blame
d---------	fault-injection	47	log stats plain
d---------	fb	1247	log stats plain
-rw-r--r--	feature-removal-schedule.txt	17569	log stats plain blame
d---------	filesystems	2906	log stats plain
d---------	firmware_class	76	log stats plain
-rw-r--r--	flexible-arrays.txt	4744	log stats plain blame
d---------	frv	397	log stats plain
-rw-r--r--	futex-requeue-pi.txt	5153	log stats plain blame
-rw-r--r--	gcov.txt	7700	log stats plain blame
-rw-r--r--	gpio.txt	26757	log stats plain blame
-rw-r--r--	highuid.txt	2505	log stats plain blame
-rw-r--r--	hw_random.txt	3570	log stats plain blame
d---------	hwmon	2354	log stats plain
d---------	i2c	489	log stats plain
d---------	i2o	67	log stats plain
d---------	ia64	535	log stats plain
-rw-r--r--	ics932s401	1018	log stats plain blame
d---------	ide	326	log stats plain
d---------	infiniband	200	log stats plain
-rw-r--r--	initrd.txt	14423	log stats plain blame
d---------	input	1000	log stats plain
-rw-r--r--	intel_txt.txt	10402	log stats plain blame
-rw-r--r--	io-mapping.txt	3288	log stats plain blame
-rw-r--r--	io_ordering.txt	1923	log stats plain blame
d---------	ioctl	199	log stats plain
-rw-r--r--	iostats.txt	8053	log stats plain blame
-rw-r--r--	irqflags-tracing.txt	2623	log stats plain blame
-rw-r--r--	isapnp.txt	433	log stats plain blame
d---------	isdn	984	log stats plain
d---------	ja_JP	223	log stats plain
-rw-r--r--	java.txt	10943	log stats plain blame
d---------	kbuild	241	log stats plain
d---------	kdump	78	log stats plain
-rw-r--r--	kernel-doc-nano-HOWTO.txt	11479	log stats plain blame
-rw-r--r--	kernel-docs.txt	35613	log stats plain blame
-rw-r--r--	kernel-parameters.txt	90181	log stats plain blame
-rw-r--r--	keys-request-key.txt	7590	log stats plain blame
-rw-r--r--	keys.txt	48705	log stats plain blame
-rw-r--r--	kmemcheck.txt	30566	log stats plain blame
-rw-r--r--	kmemleak.txt	7829	log stats plain blame
d---------	ko_KR	84	log stats plain
-rw-r--r--	kobject.txt	17265	log stats plain blame
-rw-r--r--	kprobes.txt	22486	log stats plain blame
-rw-r--r--	kref.txt	6283	log stats plain blame
d---------	kvm	35	log stats plain
d---------	laptops	341	log stats plain
-rw-r--r--	ldm.txt	3950	log stats plain blame
-rw-r--r--	leds-class.txt	3982	log stats plain blame
-rw-r--r--	leds-lp3944.txt	1576	log stats plain blame
d---------	lguest	183	log stats plain
-rw-r--r--	local_ops.txt	6232	log stats plain blame
-rw-r--r--	lockdep-design.txt	9005	log stats plain blame
-rw-r--r--	lockstat.txt	8049	log stats plain blame
-rw-r--r--	logo.gif	16335	log stats plain blame
-rw-r--r--	logo.txt	563	log stats plain blame
d---------	m68k	123	log stats plain
-rw-r--r--	magic-number.txt	9959	log stats plain blame
d---------	make	47	log stats plain
-rw-r--r--	mca.txt	11539	log stats plain blame
-rw-r--r--	md.txt	21262	log stats plain blame
-rw-r--r--	memory-barriers.txt	81519	log stats plain blame
-rw-r--r--	memory-hotplug.txt	14296	log stats plain blame
-rw-r--r--	memory.txt	1225	log stats plain blame
d---------	mips	81	log stats plain
d---------	misc-devices	105	log stats plain
d---------	mn10300	87	log stats plain
-rw-r--r--	mono.txt	2558	log stats plain blame
d---------	mtd	40	log stats plain
-rw-r--r--	mutex-design.txt	5901	log stats plain blame
d---------	namespaces	50	log stats plain
d---------	netlabel	229	log stats plain
d---------	networking	4186	log stats plain
-rw-r--r--	nmi_watchdog.txt	4263	log stats plain blame
-rw-r--r--	nommu-mmap.txt	11513	log stats plain blame
-rw-r--r--	numastat.txt	866	log stats plain blame
-rw-r--r--	oops-tracing.txt	12563	log stats plain blame
d---------	parisc	110	log stats plain
-rw-r--r--	parport-lowlevel.txt	32927	log stats plain blame
-rw-r--r--	parport.txt	8967	log stats plain blame
d---------	pcmcia	240	log stats plain
-rw-r--r--	pi-futex.txt	5834	log stats plain blame
-rw-r--r--	pnp.txt	6953	log stats plain blame
d---------	power	935	log stats plain
d---------	powerpc	555	log stats plain
d---------	pps	35	log stats plain
d---------	prctl	167	log stats plain
-rw-r--r--	preempt-locking.txt	5346	log stats plain blame
-rw-r--r--	printk-formats.txt	1068	log stats plain blame
-rw-r--r--	prio_tree.txt	5356	log stats plain blame
-rw-r--r--	rbtree.txt	6768	log stats plain blame
-rw-r--r--	rfkill.txt	5650	log stats plain blame
-rw-r--r--	robust-futex-ABI.txt	8871	log stats plain blame
-rw-r--r--	robust-futexes.txt	9647	log stats plain blame
-rw-r--r--	rt-mutex-design.txt	33567	log stats plain blame
-rw-r--r--	rt-mutex.txt	3590	log stats plain blame
-rw-r--r--	rtc.txt	16519	log stats plain blame
d---------	s390	533	log stats plain
d---------	scheduler	309	log stats plain
d---------	scsi	2106	log stats plain
-rw-r--r--	serial-console.txt	4139	log stats plain blame
d---------	serial	503	log stats plain
-rw-r--r--	sgi-ioc4.txt	2025	log stats plain blame
-rw-r--r--	sgi-visws.txt	678	log stats plain blame
d---------	sh	124	log stats plain
-rw-r--r--	slow-work.txt	5521	log stats plain blame
d---------	sound	61	log stats plain
d---------	sparc	38	log stats plain
-rw-r--r--	sparse.txt	3133	log stats plain blame
d---------	spi	338	log stats plain
-rw-r--r--	spinlocks.txt	9024	log stats plain blame
-rw-r--r--	stable_api_nonsense.txt	9397	log stats plain blame
-rw-r--r--	stable_kernel_rules.txt	2910	log stats plain blame
-rw-r--r--	svga.txt	14402	log stats plain blame
d---------	sysctl	330	log stats plain
-rw-r--r--	sysfs-rules.txt	8318	log stats plain blame
-rw-r--r--	sysrq.txt	11717	log stats plain blame
d---------	telephony	71	log stats plain
d---------	thermal	41	log stats plain
d---------	timers	194	log stats plain
-rw-r--r--	tomoyo.txt	2253	log stats plain blame
d---------	trace	479	log stats plain
d---------	uml	51	log stats plain
-rw-r--r--	unaligned-memory-access.txt	10259	log stats plain blame
-rw-r--r--	unicode.txt	6680	log stats plain blame
-rw-r--r--	unshare.txt	13376	log stats plain blame
d---------	usb	1091	log stats plain
-rw-r--r--	vgaarbiter.txt	8304	log stats plain blame
-rw-r--r--	video-output.txt	1096	log stats plain blame
d---------	video4linux	2075	log stats plain
d---------	vm	713	log stats plain
-rw-r--r--	volatile-considered-harmful.txt	5691	log stats plain blame
-rw-r--r--	voyager.txt	3493	log stats plain blame
d---------	w1	179	log stats plain
d---------	watchdog	227	log stats plain
d---------	wimax	81	log stats plain
d---------	x86	389	log stats plain
d---------	zh_CN	405	log stats plain
-rw-r--r--	zorro.txt	2886	log stats plain blame