raid1.c 83.6 KB
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/*
 * raid1.c : Multiple Devices driver for Linux
 *
 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
 *
 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
 *
 * RAID-1 management functions.
 *
 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
 *
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 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
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 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
 *
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 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
 * bitmapped intelligence in resync:
 *
 *      - bitmap marked during normal i/o
 *      - bitmap used to skip nondirty blocks during sync
 *
 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
 * - persistent bitmap code
 *
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 * 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.
 */

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#include <linux/slab.h>
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#include <linux/delay.h>
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#include <linux/blkdev.h>
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#include <linux/module.h>
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#include <linux/seq_file.h>
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#include <linux/ratelimit.h>
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#include "md.h"
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#include "raid1.h"
#include "bitmap.h"
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/*
 * Number of guaranteed r1bios in case of extreme VM load:
 */
#define	NR_RAID1_BIOS 256

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/* when we get a read error on a read-only array, we redirect to another
 * device without failing the first device, or trying to over-write to
 * correct the read error.  To keep track of bad blocks on a per-bio
 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
 */
#define IO_BLOCKED ((struct bio *)1)
/* When we successfully write to a known bad-block, we need to remove the
 * bad-block marking which must be done from process context.  So we record
 * the success by setting devs[n].bio to IO_MADE_GOOD
 */
#define IO_MADE_GOOD ((struct bio *)2)

#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)

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/* When there are this many requests queue to be written by
 * the raid1 thread, we become 'congested' to provide back-pressure
 * for writeback.
 */
static int max_queued_requests = 1024;
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static void allow_barrier(struct r1conf *conf);
static void lower_barrier(struct r1conf *conf);
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static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
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{
	struct pool_info *pi = data;
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	int size = offsetof(struct r1bio, bios[pi->raid_disks]);
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	/* allocate a r1bio with room for raid_disks entries in the bios array */
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	return kzalloc(size, gfp_flags);
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}

static void r1bio_pool_free(void *r1_bio, void *data)
{
	kfree(r1_bio);
}

#define RESYNC_BLOCK_SIZE (64*1024)
//#define RESYNC_BLOCK_SIZE PAGE_SIZE
#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
#define RESYNC_WINDOW (2048*1024)

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static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
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{
	struct pool_info *pi = data;
	struct page *page;
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	struct r1bio *r1_bio;
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	struct bio *bio;
	int i, j;

	r1_bio = r1bio_pool_alloc(gfp_flags, pi);
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	if (!r1_bio)
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		return NULL;

	/*
	 * Allocate bios : 1 for reading, n-1 for writing
	 */
	for (j = pi->raid_disks ; j-- ; ) {
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		bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
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		if (!bio)
			goto out_free_bio;
		r1_bio->bios[j] = bio;
	}
	/*
	 * Allocate RESYNC_PAGES data pages and attach them to
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	 * the first bio.
	 * If this is a user-requested check/repair, allocate
	 * RESYNC_PAGES for each bio.
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	 */
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	if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
		j = pi->raid_disks;
	else
		j = 1;
	while(j--) {
		bio = r1_bio->bios[j];
		for (i = 0; i < RESYNC_PAGES; i++) {
			page = alloc_page(gfp_flags);
			if (unlikely(!page))
				goto out_free_pages;

			bio->bi_io_vec[i].bv_page = page;
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			bio->bi_vcnt = i+1;
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		}
	}
	/* If not user-requests, copy the page pointers to all bios */
	if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
		for (i=0; i<RESYNC_PAGES ; i++)
			for (j=1; j<pi->raid_disks; j++)
				r1_bio->bios[j]->bi_io_vec[i].bv_page =
					r1_bio->bios[0]->bi_io_vec[i].bv_page;
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	}

	r1_bio->master_bio = NULL;

	return r1_bio;

out_free_pages:
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	for (j=0 ; j < pi->raid_disks; j++)
		for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++)
			put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
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	j = -1;
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out_free_bio:
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	while (++j < pi->raid_disks)
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		bio_put(r1_bio->bios[j]);
	r1bio_pool_free(r1_bio, data);
	return NULL;
}

static void r1buf_pool_free(void *__r1_bio, void *data)
{
	struct pool_info *pi = data;
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	int i,j;
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	struct r1bio *r1bio = __r1_bio;
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	for (i = 0; i < RESYNC_PAGES; i++)
		for (j = pi->raid_disks; j-- ;) {
			if (j == 0 ||
			    r1bio->bios[j]->bi_io_vec[i].bv_page !=
			    r1bio->bios[0]->bi_io_vec[i].bv_page)
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				safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
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		}
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	for (i=0 ; i < pi->raid_disks; i++)
		bio_put(r1bio->bios[i]);

	r1bio_pool_free(r1bio, data);
}

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static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
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{
	int i;

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	for (i = 0; i < conf->raid_disks * 2; i++) {
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		struct bio **bio = r1_bio->bios + i;
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		if (!BIO_SPECIAL(*bio))
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			bio_put(*bio);
		*bio = NULL;
	}
}

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static void free_r1bio(struct r1bio *r1_bio)
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{
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	struct r1conf *conf = r1_bio->mddev->private;
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	put_all_bios(conf, r1_bio);
	mempool_free(r1_bio, conf->r1bio_pool);
}

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static void put_buf(struct r1bio *r1_bio)
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{
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	struct r1conf *conf = r1_bio->mddev->private;
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	int i;

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	for (i = 0; i < conf->raid_disks * 2; i++) {
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		struct bio *bio = r1_bio->bios[i];
		if (bio->bi_end_io)
			rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
	}
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	mempool_free(r1_bio, conf->r1buf_pool);

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	lower_barrier(conf);
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}

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static void reschedule_retry(struct r1bio *r1_bio)
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{
	unsigned long flags;
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	struct mddev *mddev = r1_bio->mddev;
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	struct r1conf *conf = mddev->private;
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	spin_lock_irqsave(&conf->device_lock, flags);
	list_add(&r1_bio->retry_list, &conf->retry_list);
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	conf->nr_queued ++;
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	spin_unlock_irqrestore(&conf->device_lock, flags);

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	wake_up(&conf->wait_barrier);
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	md_wakeup_thread(mddev->thread);
}

/*
 * raid_end_bio_io() is called when we have finished servicing a mirrored
 * operation and are ready to return a success/failure code to the buffer
 * cache layer.
 */
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static void call_bio_endio(struct r1bio *r1_bio)
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{
	struct bio *bio = r1_bio->master_bio;
	int done;
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	struct r1conf *conf = r1_bio->mddev->private;
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	if (bio->bi_phys_segments) {
		unsigned long flags;
		spin_lock_irqsave(&conf->device_lock, flags);
		bio->bi_phys_segments--;
		done = (bio->bi_phys_segments == 0);
		spin_unlock_irqrestore(&conf->device_lock, flags);
	} else
		done = 1;

	if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
		clear_bit(BIO_UPTODATE, &bio->bi_flags);
	if (done) {
		bio_endio(bio, 0);
		/*
		 * Wake up any possible resync thread that waits for the device
		 * to go idle.
		 */
		allow_barrier(conf);
	}
}

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static void raid_end_bio_io(struct r1bio *r1_bio)
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{
	struct bio *bio = r1_bio->master_bio;

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	/* if nobody has done the final endio yet, do it now */
	if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
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		pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
			 (bio_data_dir(bio) == WRITE) ? "write" : "read",
			 (unsigned long long) bio->bi_sector,
			 (unsigned long long) bio->bi_sector +
			 (bio->bi_size >> 9) - 1);
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		call_bio_endio(r1_bio);
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	}
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	free_r1bio(r1_bio);
}

/*
 * Update disk head position estimator based on IRQ completion info.
 */
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static inline void update_head_pos(int disk, struct r1bio *r1_bio)
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{
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	struct r1conf *conf = r1_bio->mddev->private;
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	conf->mirrors[disk].head_position =
		r1_bio->sector + (r1_bio->sectors);
}

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/*
 * Find the disk number which triggered given bio
 */
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static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
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{
	int mirror;
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	struct r1conf *conf = r1_bio->mddev->private;
	int raid_disks = conf->raid_disks;
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	for (mirror = 0; mirror < raid_disks * 2; mirror++)
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		if (r1_bio->bios[mirror] == bio)
			break;

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	BUG_ON(mirror == raid_disks * 2);
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	update_head_pos(mirror, r1_bio);

	return mirror;
}

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static void raid1_end_read_request(struct bio *bio, int error)
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{
	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
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	struct r1bio *r1_bio = bio->bi_private;
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	int mirror;
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	struct r1conf *conf = r1_bio->mddev->private;
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	mirror = r1_bio->read_disk;
	/*
	 * this branch is our 'one mirror IO has finished' event handler:
	 */
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	update_head_pos(mirror, r1_bio);

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	if (uptodate)
		set_bit(R1BIO_Uptodate, &r1_bio->state);
	else {
		/* If all other devices have failed, we want to return
		 * the error upwards rather than fail the last device.
		 * Here we redefine "uptodate" to mean "Don't want to retry"
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		 */
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		unsigned long flags;
		spin_lock_irqsave(&conf->device_lock, flags);
		if (r1_bio->mddev->degraded == conf->raid_disks ||
		    (r1_bio->mddev->degraded == conf->raid_disks-1 &&
		     !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
			uptodate = 1;
		spin_unlock_irqrestore(&conf->device_lock, flags);
	}
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	if (uptodate) {
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		raid_end_bio_io(r1_bio);
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		rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
	} else {
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		/*
		 * oops, read error:
		 */
		char b[BDEVNAME_SIZE];
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		printk_ratelimited(
			KERN_ERR "md/raid1:%s: %s: "
			"rescheduling sector %llu\n",
			mdname(conf->mddev),
			bdevname(conf->mirrors[mirror].rdev->bdev,
				 b),
			(unsigned long long)r1_bio->sector);
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		set_bit(R1BIO_ReadError, &r1_bio->state);
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		reschedule_retry(r1_bio);
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		/* don't drop the reference on read_disk yet */
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	}
}

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static void close_write(struct r1bio *r1_bio)
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{
	/* it really is the end of this request */
	if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
		/* free extra copy of the data pages */
		int i = r1_bio->behind_page_count;
		while (i--)
			safe_put_page(r1_bio->behind_bvecs[i].bv_page);
		kfree(r1_bio->behind_bvecs);
		r1_bio->behind_bvecs = NULL;
	}
	/* clear the bitmap if all writes complete successfully */
	bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
			r1_bio->sectors,
			!test_bit(R1BIO_Degraded, &r1_bio->state),
			test_bit(R1BIO_BehindIO, &r1_bio->state));
	md_write_end(r1_bio->mddev);
}

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static void r1_bio_write_done(struct r1bio *r1_bio)
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{
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	if (!atomic_dec_and_test(&r1_bio->remaining))
		return;

	if (test_bit(R1BIO_WriteError, &r1_bio->state))
		reschedule_retry(r1_bio);
	else {
		close_write(r1_bio);
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		if (test_bit(R1BIO_MadeGood, &r1_bio->state))
			reschedule_retry(r1_bio);
		else
			raid_end_bio_io(r1_bio);
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	}
}

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static void raid1_end_write_request(struct bio *bio, int error)
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{
	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
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	struct r1bio *r1_bio = bio->bi_private;
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	int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
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	struct r1conf *conf = r1_bio->mddev->private;
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	struct bio *to_put = NULL;
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	mirror = find_bio_disk(r1_bio, bio);
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	/*
	 * 'one mirror IO has finished' event handler:
	 */
	if (!uptodate) {
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		set_bit(WriteErrorSeen,
			&conf->mirrors[mirror].rdev->flags);
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		if (!test_and_set_bit(WantReplacement,
				      &conf->mirrors[mirror].rdev->flags))
			set_bit(MD_RECOVERY_NEEDED, &
				conf->mddev->recovery);

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		set_bit(R1BIO_WriteError, &r1_bio->state);
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	} else {
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		/*
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		 * Set R1BIO_Uptodate in our master bio, so that we
		 * will return a good error code for to the higher
		 * levels even if IO on some other mirrored buffer
		 * fails.
		 *
		 * The 'master' represents the composite IO operation
		 * to user-side. So if something waits for IO, then it
		 * will wait for the 'master' bio.
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		 */
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		sector_t first_bad;
		int bad_sectors;

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		r1_bio->bios[mirror] = NULL;
		to_put = bio;
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		set_bit(R1BIO_Uptodate, &r1_bio->state);

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		/* Maybe we can clear some bad blocks. */
		if (is_badblock(conf->mirrors[mirror].rdev,
				r1_bio->sector, r1_bio->sectors,
				&first_bad, &bad_sectors)) {
			r1_bio->bios[mirror] = IO_MADE_GOOD;
			set_bit(R1BIO_MadeGood, &r1_bio->state);
		}
	}

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	if (behind) {
		if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
			atomic_dec(&r1_bio->behind_remaining);

		/*
		 * In behind mode, we ACK the master bio once the I/O
		 * has safely reached all non-writemostly
		 * disks. Setting the Returned bit ensures that this
		 * gets done only once -- we don't ever want to return
		 * -EIO here, instead we'll wait
		 */
		if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
		    test_bit(R1BIO_Uptodate, &r1_bio->state)) {
			/* Maybe we can return now */
			if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
				struct bio *mbio = r1_bio->master_bio;
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				pr_debug("raid1: behind end write sectors"
					 " %llu-%llu\n",
					 (unsigned long long) mbio->bi_sector,
					 (unsigned long long) mbio->bi_sector +
					 (mbio->bi_size >> 9) - 1);
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				call_bio_endio(r1_bio);
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			}
		}
	}
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	if (r1_bio->bios[mirror] == NULL)
		rdev_dec_pending(conf->mirrors[mirror].rdev,
				 conf->mddev);
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	/*
	 * Let's see if all mirrored write operations have finished
	 * already.
	 */
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	r1_bio_write_done(r1_bio);
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	if (to_put)
		bio_put(to_put);
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}


/*
 * This routine returns the disk from which the requested read should
 * be done. There is a per-array 'next expected sequential IO' sector
 * number - if this matches on the next IO then we use the last disk.
 * There is also a per-disk 'last know head position' sector that is
 * maintained from IRQ contexts, both the normal and the resync IO
 * completion handlers update this position correctly. If there is no
 * perfect sequential match then we pick the disk whose head is closest.
 *
 * If there are 2 mirrors in the same 2 devices, performance degrades
 * because position is mirror, not device based.
 *
 * The rdev for the device selected will have nr_pending incremented.
 */
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static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
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{
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	const sector_t this_sector = r1_bio->sector;
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	int sectors;
	int best_good_sectors;
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	int best_disk, best_dist_disk, best_pending_disk;
	int has_nonrot_disk;
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	int disk;
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	sector_t best_dist;
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	unsigned int min_pending;
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	struct md_rdev *rdev;
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	int choose_first;
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	int choose_next_idle;
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	rcu_read_lock();
	/*
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	 * Check if we can balance. We can balance on the whole
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	 * device if no resync is going on, or below the resync window.
	 * We take the first readable disk when above the resync window.
	 */
 retry:
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	sectors = r1_bio->sectors;
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	best_disk = -1;
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	best_dist_disk = -1;
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	best_dist = MaxSector;
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	best_pending_disk = -1;
	min_pending = UINT_MAX;
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	best_good_sectors = 0;
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	has_nonrot_disk = 0;
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	choose_next_idle = 0;
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	if (conf->mddev->recovery_cp < MaxSector &&
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	    (this_sector + sectors >= conf->next_resync))
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		choose_first = 1;
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	else
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		choose_first = 0;
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	for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
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533
		sector_t dist;
534 535
		sector_t first_bad;
		int bad_sectors;
536
		unsigned int pending;
537
		bool nonrot;
538

539 540 541
		rdev = rcu_dereference(conf->mirrors[disk].rdev);
		if (r1_bio->bios[disk] == IO_BLOCKED
		    || rdev == NULL
542
		    || test_bit(Unmerged, &rdev->flags)
N
NeilBrown 已提交
543
		    || test_bit(Faulty, &rdev->flags))
544
			continue;
N
NeilBrown 已提交
545 546
		if (!test_bit(In_sync, &rdev->flags) &&
		    rdev->recovery_offset < this_sector + sectors)
L
Linus Torvalds 已提交
547
			continue;
N
NeilBrown 已提交
548 549 550
		if (test_bit(WriteMostly, &rdev->flags)) {
			/* Don't balance among write-mostly, just
			 * use the first as a last resort */
551 552 553 554 555 556 557 558 559
			if (best_disk < 0) {
				if (is_badblock(rdev, this_sector, sectors,
						&first_bad, &bad_sectors)) {
					if (first_bad < this_sector)
						/* Cannot use this */
						continue;
					best_good_sectors = first_bad - this_sector;
				} else
					best_good_sectors = sectors;
N
NeilBrown 已提交
560
				best_disk = disk;
561
			}
N
NeilBrown 已提交
562 563 564 565 566
			continue;
		}
		/* This is a reasonable device to use.  It might
		 * even be best.
		 */
567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595
		if (is_badblock(rdev, this_sector, sectors,
				&first_bad, &bad_sectors)) {
			if (best_dist < MaxSector)
				/* already have a better device */
				continue;
			if (first_bad <= this_sector) {
				/* cannot read here. If this is the 'primary'
				 * device, then we must not read beyond
				 * bad_sectors from another device..
				 */
				bad_sectors -= (this_sector - first_bad);
				if (choose_first && sectors > bad_sectors)
					sectors = bad_sectors;
				if (best_good_sectors > sectors)
					best_good_sectors = sectors;

			} else {
				sector_t good_sectors = first_bad - this_sector;
				if (good_sectors > best_good_sectors) {
					best_good_sectors = good_sectors;
					best_disk = disk;
				}
				if (choose_first)
					break;
			}
			continue;
		} else
			best_good_sectors = sectors;

596 597
		nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev));
		has_nonrot_disk |= nonrot;
598
		pending = atomic_read(&rdev->nr_pending);
N
NeilBrown 已提交
599
		dist = abs(this_sector - conf->mirrors[disk].head_position);
600
		if (choose_first) {
N
NeilBrown 已提交
601
			best_disk = disk;
L
Linus Torvalds 已提交
602 603
			break;
		}
604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641
		/* Don't change to another disk for sequential reads */
		if (conf->mirrors[disk].next_seq_sect == this_sector
		    || dist == 0) {
			int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
			struct raid1_info *mirror = &conf->mirrors[disk];

			best_disk = disk;
			/*
			 * If buffered sequential IO size exceeds optimal
			 * iosize, check if there is idle disk. If yes, choose
			 * the idle disk. read_balance could already choose an
			 * idle disk before noticing it's a sequential IO in
			 * this disk. This doesn't matter because this disk
			 * will idle, next time it will be utilized after the
			 * first disk has IO size exceeds optimal iosize. In
			 * this way, iosize of the first disk will be optimal
			 * iosize at least. iosize of the second disk might be
			 * small, but not a big deal since when the second disk
			 * starts IO, the first disk is likely still busy.
			 */
			if (nonrot && opt_iosize > 0 &&
			    mirror->seq_start != MaxSector &&
			    mirror->next_seq_sect > opt_iosize &&
			    mirror->next_seq_sect - opt_iosize >=
			    mirror->seq_start) {
				choose_next_idle = 1;
				continue;
			}
			break;
		}
		/* If device is idle, use it */
		if (pending == 0) {
			best_disk = disk;
			break;
		}

		if (choose_next_idle)
			continue;
642 643 644 645 646 647

		if (min_pending > pending) {
			min_pending = pending;
			best_pending_disk = disk;
		}

N
NeilBrown 已提交
648 649
		if (dist < best_dist) {
			best_dist = dist;
650
			best_dist_disk = disk;
L
Linus Torvalds 已提交
651
		}
652
	}
L
Linus Torvalds 已提交
653

654 655 656 657 658 659 660 661 662 663 664 665 666
	/*
	 * If all disks are rotational, choose the closest disk. If any disk is
	 * non-rotational, choose the disk with less pending request even the
	 * disk is rotational, which might/might not be optimal for raids with
	 * mixed ratation/non-rotational disks depending on workload.
	 */
	if (best_disk == -1) {
		if (has_nonrot_disk)
			best_disk = best_pending_disk;
		else
			best_disk = best_dist_disk;
	}

N
NeilBrown 已提交
667 668
	if (best_disk >= 0) {
		rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
669 670 671
		if (!rdev)
			goto retry;
		atomic_inc(&rdev->nr_pending);
N
NeilBrown 已提交
672
		if (test_bit(Faulty, &rdev->flags)) {
L
Linus Torvalds 已提交
673 674 675
			/* cannot risk returning a device that failed
			 * before we inc'ed nr_pending
			 */
676
			rdev_dec_pending(rdev, conf->mddev);
L
Linus Torvalds 已提交
677 678
			goto retry;
		}
679
		sectors = best_good_sectors;
680 681 682 683

		if (conf->mirrors[best_disk].next_seq_sect != this_sector)
			conf->mirrors[best_disk].seq_start = this_sector;

684
		conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
L
Linus Torvalds 已提交
685 686
	}
	rcu_read_unlock();
687
	*max_sectors = sectors;
L
Linus Torvalds 已提交
688

N
NeilBrown 已提交
689
	return best_disk;
L
Linus Torvalds 已提交
690 691
}

692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724
static int raid1_mergeable_bvec(struct request_queue *q,
				struct bvec_merge_data *bvm,
				struct bio_vec *biovec)
{
	struct mddev *mddev = q->queuedata;
	struct r1conf *conf = mddev->private;
	sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
	int max = biovec->bv_len;

	if (mddev->merge_check_needed) {
		int disk;
		rcu_read_lock();
		for (disk = 0; disk < conf->raid_disks * 2; disk++) {
			struct md_rdev *rdev = rcu_dereference(
				conf->mirrors[disk].rdev);
			if (rdev && !test_bit(Faulty, &rdev->flags)) {
				struct request_queue *q =
					bdev_get_queue(rdev->bdev);
				if (q->merge_bvec_fn) {
					bvm->bi_sector = sector +
						rdev->data_offset;
					bvm->bi_bdev = rdev->bdev;
					max = min(max, q->merge_bvec_fn(
							  q, bvm, biovec));
				}
			}
		}
		rcu_read_unlock();
	}
	return max;

}

725
int md_raid1_congested(struct mddev *mddev, int bits)
726
{
727
	struct r1conf *conf = mddev->private;
728 729
	int i, ret = 0;

730 731 732 733
	if ((bits & (1 << BDI_async_congested)) &&
	    conf->pending_count >= max_queued_requests)
		return 1;

734
	rcu_read_lock();
735
	for (i = 0; i < conf->raid_disks * 2; i++) {
736
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
737
		if (rdev && !test_bit(Faulty, &rdev->flags)) {
738
			struct request_queue *q = bdev_get_queue(rdev->bdev);
739

740 741
			BUG_ON(!q);

742 743 744
			/* Note the '|| 1' - when read_balance prefers
			 * non-congested targets, it can be removed
			 */
745
			if ((bits & (1<<BDI_async_congested)) || 1)
746 747 748 749 750 751 752 753
				ret |= bdi_congested(&q->backing_dev_info, bits);
			else
				ret &= bdi_congested(&q->backing_dev_info, bits);
		}
	}
	rcu_read_unlock();
	return ret;
}
754
EXPORT_SYMBOL_GPL(md_raid1_congested);
755

756 757
static int raid1_congested(void *data, int bits)
{
758
	struct mddev *mddev = data;
759 760 761 762

	return mddev_congested(mddev, bits) ||
		md_raid1_congested(mddev, bits);
}
763

764
static void flush_pending_writes(struct r1conf *conf)
765 766 767 768 769 770 771 772 773
{
	/* Any writes that have been queued but are awaiting
	 * bitmap updates get flushed here.
	 */
	spin_lock_irq(&conf->device_lock);

	if (conf->pending_bio_list.head) {
		struct bio *bio;
		bio = bio_list_get(&conf->pending_bio_list);
774
		conf->pending_count = 0;
775 776 777 778
		spin_unlock_irq(&conf->device_lock);
		/* flush any pending bitmap writes to
		 * disk before proceeding w/ I/O */
		bitmap_unplug(conf->mddev->bitmap);
779
		wake_up(&conf->wait_barrier);
780 781 782 783

		while (bio) { /* submit pending writes */
			struct bio *next = bio->bi_next;
			bio->bi_next = NULL;
S
Shaohua Li 已提交
784 785 786 787 788 789
			if (unlikely((bio->bi_rw & REQ_DISCARD) &&
			    !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
				/* Just ignore it */
				bio_endio(bio, 0);
			else
				generic_make_request(bio);
790 791 792 793
			bio = next;
		}
	} else
		spin_unlock_irq(&conf->device_lock);
J
Jens Axboe 已提交
794 795
}

796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815
/* Barriers....
 * Sometimes we need to suspend IO while we do something else,
 * either some resync/recovery, or reconfigure the array.
 * To do this we raise a 'barrier'.
 * The 'barrier' is a counter that can be raised multiple times
 * to count how many activities are happening which preclude
 * normal IO.
 * We can only raise the barrier if there is no pending IO.
 * i.e. if nr_pending == 0.
 * We choose only to raise the barrier if no-one is waiting for the
 * barrier to go down.  This means that as soon as an IO request
 * is ready, no other operations which require a barrier will start
 * until the IO request has had a chance.
 *
 * So: regular IO calls 'wait_barrier'.  When that returns there
 *    is no backgroup IO happening,  It must arrange to call
 *    allow_barrier when it has finished its IO.
 * backgroup IO calls must call raise_barrier.  Once that returns
 *    there is no normal IO happeing.  It must arrange to call
 *    lower_barrier when the particular background IO completes.
L
Linus Torvalds 已提交
816 817 818
 */
#define RESYNC_DEPTH 32

819
static void raise_barrier(struct r1conf *conf)
L
Linus Torvalds 已提交
820 821
{
	spin_lock_irq(&conf->resync_lock);
822 823 824

	/* Wait until no block IO is waiting */
	wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
825
			    conf->resync_lock);
826 827 828 829

	/* block any new IO from starting */
	conf->barrier++;

N
NeilBrown 已提交
830
	/* Now wait for all pending IO to complete */
831 832
	wait_event_lock_irq(conf->wait_barrier,
			    !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
833
			    conf->resync_lock);
834 835 836 837

	spin_unlock_irq(&conf->resync_lock);
}

838
static void lower_barrier(struct r1conf *conf)
839 840
{
	unsigned long flags;
841
	BUG_ON(conf->barrier <= 0);
842 843 844 845 846 847
	spin_lock_irqsave(&conf->resync_lock, flags);
	conf->barrier--;
	spin_unlock_irqrestore(&conf->resync_lock, flags);
	wake_up(&conf->wait_barrier);
}

848
static void wait_barrier(struct r1conf *conf)
849 850 851 852
{
	spin_lock_irq(&conf->resync_lock);
	if (conf->barrier) {
		conf->nr_waiting++;
853 854 855 856 857 858 859 860 861 862 863 864 865 866
		/* Wait for the barrier to drop.
		 * However if there are already pending
		 * requests (preventing the barrier from
		 * rising completely), and the
		 * pre-process bio queue isn't empty,
		 * then don't wait, as we need to empty
		 * that queue to get the nr_pending
		 * count down.
		 */
		wait_event_lock_irq(conf->wait_barrier,
				    !conf->barrier ||
				    (conf->nr_pending &&
				     current->bio_list &&
				     !bio_list_empty(current->bio_list)),
867
				    conf->resync_lock);
868
		conf->nr_waiting--;
L
Linus Torvalds 已提交
869
	}
870
	conf->nr_pending++;
L
Linus Torvalds 已提交
871 872 873
	spin_unlock_irq(&conf->resync_lock);
}

874
static void allow_barrier(struct r1conf *conf)
875 876 877 878 879 880 881 882
{
	unsigned long flags;
	spin_lock_irqsave(&conf->resync_lock, flags);
	conf->nr_pending--;
	spin_unlock_irqrestore(&conf->resync_lock, flags);
	wake_up(&conf->wait_barrier);
}

883
static void freeze_array(struct r1conf *conf)
884 885 886 887
{
	/* stop syncio and normal IO and wait for everything to
	 * go quite.
	 * We increment barrier and nr_waiting, and then
888 889 890 891 892 893 894 895
	 * wait until nr_pending match nr_queued+1
	 * This is called in the context of one normal IO request
	 * that has failed. Thus any sync request that might be pending
	 * will be blocked by nr_pending, and we need to wait for
	 * pending IO requests to complete or be queued for re-try.
	 * Thus the number queued (nr_queued) plus this request (1)
	 * must match the number of pending IOs (nr_pending) before
	 * we continue.
896 897 898 899
	 */
	spin_lock_irq(&conf->resync_lock);
	conf->barrier++;
	conf->nr_waiting++;
900 901 902 903
	wait_event_lock_irq_cmd(conf->wait_barrier,
				conf->nr_pending == conf->nr_queued+1,
				conf->resync_lock,
				flush_pending_writes(conf));
904 905
	spin_unlock_irq(&conf->resync_lock);
}
906
static void unfreeze_array(struct r1conf *conf)
907 908 909 910 911 912 913 914 915
{
	/* reverse the effect of the freeze */
	spin_lock_irq(&conf->resync_lock);
	conf->barrier--;
	conf->nr_waiting--;
	wake_up(&conf->wait_barrier);
	spin_unlock_irq(&conf->resync_lock);
}

916

917 918
/* duplicate the data pages for behind I/O 
 */
919
static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
920 921 922
{
	int i;
	struct bio_vec *bvec;
923
	struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
924
					GFP_NOIO);
925
	if (unlikely(!bvecs))
926
		return;
927 928

	bio_for_each_segment(bvec, bio, i) {
929 930 931
		bvecs[i] = *bvec;
		bvecs[i].bv_page = alloc_page(GFP_NOIO);
		if (unlikely(!bvecs[i].bv_page))
932
			goto do_sync_io;
933 934 935
		memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
		       kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
		kunmap(bvecs[i].bv_page);
936 937
		kunmap(bvec->bv_page);
	}
938
	r1_bio->behind_bvecs = bvecs;
939 940 941
	r1_bio->behind_page_count = bio->bi_vcnt;
	set_bit(R1BIO_BehindIO, &r1_bio->state);
	return;
942 943

do_sync_io:
944
	for (i = 0; i < bio->bi_vcnt; i++)
945 946 947
		if (bvecs[i].bv_page)
			put_page(bvecs[i].bv_page);
	kfree(bvecs);
948
	pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
949 950
}

951 952 953 954 955 956 957 958 959 960 961 962 963 964
struct raid1_plug_cb {
	struct blk_plug_cb	cb;
	struct bio_list		pending;
	int			pending_cnt;
};

static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
{
	struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
						  cb);
	struct mddev *mddev = plug->cb.data;
	struct r1conf *conf = mddev->private;
	struct bio *bio;

965
	if (from_schedule || current->bio_list) {
966 967 968 969
		spin_lock_irq(&conf->device_lock);
		bio_list_merge(&conf->pending_bio_list, &plug->pending);
		conf->pending_count += plug->pending_cnt;
		spin_unlock_irq(&conf->device_lock);
970
		wake_up(&conf->wait_barrier);
971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989
		md_wakeup_thread(mddev->thread);
		kfree(plug);
		return;
	}

	/* we aren't scheduling, so we can do the write-out directly. */
	bio = bio_list_get(&plug->pending);
	bitmap_unplug(mddev->bitmap);
	wake_up(&conf->wait_barrier);

	while (bio) { /* submit pending writes */
		struct bio *next = bio->bi_next;
		bio->bi_next = NULL;
		generic_make_request(bio);
		bio = next;
	}
	kfree(plug);
}

990
static void make_request(struct mddev *mddev, struct bio * bio)
L
Linus Torvalds 已提交
991
{
992
	struct r1conf *conf = mddev->private;
993
	struct raid1_info *mirror;
994
	struct r1bio *r1_bio;
L
Linus Torvalds 已提交
995
	struct bio *read_bio;
996
	int i, disks;
997
	struct bitmap *bitmap;
998
	unsigned long flags;
999
	const int rw = bio_data_dir(bio);
1000
	const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
T
Tejun Heo 已提交
1001
	const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
S
Shaohua Li 已提交
1002 1003
	const unsigned long do_discard = (bio->bi_rw
					  & (REQ_DISCARD | REQ_SECURE));
1004
	const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME);
1005
	struct md_rdev *blocked_rdev;
1006 1007
	struct blk_plug_cb *cb;
	struct raid1_plug_cb *plug = NULL;
1008 1009 1010
	int first_clone;
	int sectors_handled;
	int max_sectors;
1011

L
Linus Torvalds 已提交
1012 1013 1014 1015 1016
	/*
	 * Register the new request and wait if the reconstruction
	 * thread has put up a bar for new requests.
	 * Continue immediately if no resync is active currently.
	 */
1017

1018 1019
	md_write_start(mddev, bio); /* wait on superblock update early */

1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038
	if (bio_data_dir(bio) == WRITE &&
	    bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
	    bio->bi_sector < mddev->suspend_hi) {
		/* As the suspend_* range is controlled by
		 * userspace, we want an interruptible
		 * wait.
		 */
		DEFINE_WAIT(w);
		for (;;) {
			flush_signals(current);
			prepare_to_wait(&conf->wait_barrier,
					&w, TASK_INTERRUPTIBLE);
			if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
			    bio->bi_sector >= mddev->suspend_hi)
				break;
			schedule();
		}
		finish_wait(&conf->wait_barrier, &w);
	}
1039

1040
	wait_barrier(conf);
L
Linus Torvalds 已提交
1041

1042 1043
	bitmap = mddev->bitmap;

L
Linus Torvalds 已提交
1044 1045 1046 1047 1048 1049 1050 1051 1052
	/*
	 * make_request() can abort the operation when READA is being
	 * used and no empty request is available.
	 *
	 */
	r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);

	r1_bio->master_bio = bio;
	r1_bio->sectors = bio->bi_size >> 9;
1053
	r1_bio->state = 0;
L
Linus Torvalds 已提交
1054 1055 1056
	r1_bio->mddev = mddev;
	r1_bio->sector = bio->bi_sector;

1057 1058 1059 1060 1061 1062 1063 1064 1065 1066
	/* We might need to issue multiple reads to different
	 * devices if there are bad blocks around, so we keep
	 * track of the number of reads in bio->bi_phys_segments.
	 * If this is 0, there is only one r1_bio and no locking
	 * will be needed when requests complete.  If it is
	 * non-zero, then it is the number of not-completed requests.
	 */
	bio->bi_phys_segments = 0;
	clear_bit(BIO_SEG_VALID, &bio->bi_flags);

1067
	if (rw == READ) {
L
Linus Torvalds 已提交
1068 1069 1070
		/*
		 * read balancing logic:
		 */
1071 1072 1073 1074
		int rdisk;

read_again:
		rdisk = read_balance(conf, r1_bio, &max_sectors);
L
Linus Torvalds 已提交
1075 1076 1077 1078

		if (rdisk < 0) {
			/* couldn't find anywhere to read from */
			raid_end_bio_io(r1_bio);
1079
			return;
L
Linus Torvalds 已提交
1080 1081 1082
		}
		mirror = conf->mirrors + rdisk;

1083 1084 1085 1086 1087 1088 1089 1090 1091
		if (test_bit(WriteMostly, &mirror->rdev->flags) &&
		    bitmap) {
			/* Reading from a write-mostly device must
			 * take care not to over-take any writes
			 * that are 'behind'
			 */
			wait_event(bitmap->behind_wait,
				   atomic_read(&bitmap->behind_writes) == 0);
		}
L
Linus Torvalds 已提交
1092 1093
		r1_bio->read_disk = rdisk;

1094
		read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1095 1096
		md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
			    max_sectors);
L
Linus Torvalds 已提交
1097 1098 1099 1100 1101 1102

		r1_bio->bios[rdisk] = read_bio;

		read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
		read_bio->bi_bdev = mirror->rdev->bdev;
		read_bio->bi_end_io = raid1_end_read_request;
1103
		read_bio->bi_rw = READ | do_sync;
L
Linus Torvalds 已提交
1104 1105
		read_bio->bi_private = r1_bio;

1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136
		if (max_sectors < r1_bio->sectors) {
			/* could not read all from this device, so we will
			 * need another r1_bio.
			 */

			sectors_handled = (r1_bio->sector + max_sectors
					   - bio->bi_sector);
			r1_bio->sectors = max_sectors;
			spin_lock_irq(&conf->device_lock);
			if (bio->bi_phys_segments == 0)
				bio->bi_phys_segments = 2;
			else
				bio->bi_phys_segments++;
			spin_unlock_irq(&conf->device_lock);
			/* Cannot call generic_make_request directly
			 * as that will be queued in __make_request
			 * and subsequent mempool_alloc might block waiting
			 * for it.  So hand bio over to raid1d.
			 */
			reschedule_retry(r1_bio);

			r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);

			r1_bio->master_bio = bio;
			r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
			r1_bio->state = 0;
			r1_bio->mddev = mddev;
			r1_bio->sector = bio->bi_sector + sectors_handled;
			goto read_again;
		} else
			generic_make_request(read_bio);
1137
		return;
L
Linus Torvalds 已提交
1138 1139 1140 1141 1142
	}

	/*
	 * WRITE:
	 */
1143 1144 1145 1146 1147
	if (conf->pending_count >= max_queued_requests) {
		md_wakeup_thread(mddev->thread);
		wait_event(conf->wait_barrier,
			   conf->pending_count < max_queued_requests);
	}
1148
	/* first select target devices under rcu_lock and
L
Linus Torvalds 已提交
1149 1150
	 * inc refcount on their rdev.  Record them by setting
	 * bios[x] to bio
1151 1152 1153 1154 1155 1156
	 * If there are known/acknowledged bad blocks on any device on
	 * which we have seen a write error, we want to avoid writing those
	 * blocks.
	 * This potentially requires several writes to write around
	 * the bad blocks.  Each set of writes gets it's own r1bio
	 * with a set of bios attached.
L
Linus Torvalds 已提交
1157
	 */
N
NeilBrown 已提交
1158

1159
	disks = conf->raid_disks * 2;
1160 1161
 retry_write:
	blocked_rdev = NULL;
L
Linus Torvalds 已提交
1162
	rcu_read_lock();
1163
	max_sectors = r1_bio->sectors;
L
Linus Torvalds 已提交
1164
	for (i = 0;  i < disks; i++) {
1165
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1166 1167 1168 1169 1170
		if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
			atomic_inc(&rdev->nr_pending);
			blocked_rdev = rdev;
			break;
		}
1171
		r1_bio->bios[i] = NULL;
1172 1173
		if (!rdev || test_bit(Faulty, &rdev->flags)
		    || test_bit(Unmerged, &rdev->flags)) {
1174 1175
			if (i < conf->raid_disks)
				set_bit(R1BIO_Degraded, &r1_bio->state);
1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
			continue;
		}

		atomic_inc(&rdev->nr_pending);
		if (test_bit(WriteErrorSeen, &rdev->flags)) {
			sector_t first_bad;
			int bad_sectors;
			int is_bad;

			is_bad = is_badblock(rdev, r1_bio->sector,
					     max_sectors,
					     &first_bad, &bad_sectors);
			if (is_bad < 0) {
				/* mustn't write here until the bad block is
				 * acknowledged*/
				set_bit(BlockedBadBlocks, &rdev->flags);
				blocked_rdev = rdev;
				break;
			}
			if (is_bad && first_bad <= r1_bio->sector) {
				/* Cannot write here at all */
				bad_sectors -= (r1_bio->sector - first_bad);
				if (bad_sectors < max_sectors)
					/* mustn't write more than bad_sectors
					 * to other devices yet
					 */
					max_sectors = bad_sectors;
1203
				rdev_dec_pending(rdev, mddev);
1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214
				/* We don't set R1BIO_Degraded as that
				 * only applies if the disk is
				 * missing, so it might be re-added,
				 * and we want to know to recover this
				 * chunk.
				 * In this case the device is here,
				 * and the fact that this chunk is not
				 * in-sync is recorded in the bad
				 * block log
				 */
				continue;
1215
			}
1216 1217 1218 1219 1220 1221 1222
			if (is_bad) {
				int good_sectors = first_bad - r1_bio->sector;
				if (good_sectors < max_sectors)
					max_sectors = good_sectors;
			}
		}
		r1_bio->bios[i] = bio;
L
Linus Torvalds 已提交
1223 1224 1225
	}
	rcu_read_unlock();

1226 1227 1228 1229 1230 1231 1232
	if (unlikely(blocked_rdev)) {
		/* Wait for this device to become unblocked */
		int j;

		for (j = 0; j < i; j++)
			if (r1_bio->bios[j])
				rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1233
		r1_bio->state = 0;
1234 1235 1236 1237 1238 1239
		allow_barrier(conf);
		md_wait_for_blocked_rdev(blocked_rdev, mddev);
		wait_barrier(conf);
		goto retry_write;
	}

1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250
	if (max_sectors < r1_bio->sectors) {
		/* We are splitting this write into multiple parts, so
		 * we need to prepare for allocating another r1_bio.
		 */
		r1_bio->sectors = max_sectors;
		spin_lock_irq(&conf->device_lock);
		if (bio->bi_phys_segments == 0)
			bio->bi_phys_segments = 2;
		else
			bio->bi_phys_segments++;
		spin_unlock_irq(&conf->device_lock);
1251
	}
1252
	sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
1253

1254
	atomic_set(&r1_bio->remaining, 1);
1255
	atomic_set(&r1_bio->behind_remaining, 0);
1256

1257
	first_clone = 1;
L
Linus Torvalds 已提交
1258 1259 1260 1261 1262
	for (i = 0; i < disks; i++) {
		struct bio *mbio;
		if (!r1_bio->bios[i])
			continue;

1263
		mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282
		md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);

		if (first_clone) {
			/* do behind I/O ?
			 * Not if there are too many, or cannot
			 * allocate memory, or a reader on WriteMostly
			 * is waiting for behind writes to flush */
			if (bitmap &&
			    (atomic_read(&bitmap->behind_writes)
			     < mddev->bitmap_info.max_write_behind) &&
			    !waitqueue_active(&bitmap->behind_wait))
				alloc_behind_pages(mbio, r1_bio);

			bitmap_startwrite(bitmap, r1_bio->sector,
					  r1_bio->sectors,
					  test_bit(R1BIO_BehindIO,
						   &r1_bio->state));
			first_clone = 0;
		}
1283
		if (r1_bio->behind_bvecs) {
1284 1285 1286 1287 1288 1289 1290
			struct bio_vec *bvec;
			int j;

			/* Yes, I really want the '__' version so that
			 * we clear any unused pointer in the io_vec, rather
			 * than leave them unchanged.  This is important
			 * because when we come to free the pages, we won't
N
NeilBrown 已提交
1291
			 * know the original bi_idx, so we just free
1292 1293 1294
			 * them all
			 */
			__bio_for_each_segment(bvec, mbio, j, 0)
1295
				bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1296 1297 1298 1299
			if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
				atomic_inc(&r1_bio->behind_remaining);
		}

1300 1301 1302 1303 1304 1305
		r1_bio->bios[i] = mbio;

		mbio->bi_sector	= (r1_bio->sector +
				   conf->mirrors[i].rdev->data_offset);
		mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
		mbio->bi_end_io	= raid1_end_write_request;
1306 1307
		mbio->bi_rw =
			WRITE | do_flush_fua | do_sync | do_discard | do_same;
1308 1309
		mbio->bi_private = r1_bio;

L
Linus Torvalds 已提交
1310
		atomic_inc(&r1_bio->remaining);
1311 1312 1313 1314 1315 1316

		cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
		if (cb)
			plug = container_of(cb, struct raid1_plug_cb, cb);
		else
			plug = NULL;
1317
		spin_lock_irqsave(&conf->device_lock, flags);
1318 1319 1320 1321 1322 1323 1324
		if (plug) {
			bio_list_add(&plug->pending, mbio);
			plug->pending_cnt++;
		} else {
			bio_list_add(&conf->pending_bio_list, mbio);
			conf->pending_count++;
		}
1325
		spin_unlock_irqrestore(&conf->device_lock, flags);
1326
		if (!plug)
N
NeilBrown 已提交
1327
			md_wakeup_thread(mddev->thread);
L
Linus Torvalds 已提交
1328
	}
1329 1330 1331
	/* Mustn't call r1_bio_write_done before this next test,
	 * as it could result in the bio being freed.
	 */
1332
	if (sectors_handled < (bio->bi_size >> 9)) {
1333
		r1_bio_write_done(r1_bio);
1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345
		/* We need another r1_bio.  It has already been counted
		 * in bio->bi_phys_segments
		 */
		r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
		r1_bio->master_bio = bio;
		r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
		r1_bio->state = 0;
		r1_bio->mddev = mddev;
		r1_bio->sector = bio->bi_sector + sectors_handled;
		goto retry_write;
	}

1346 1347 1348 1349
	r1_bio_write_done(r1_bio);

	/* In case raid1d snuck in to freeze_array */
	wake_up(&conf->wait_barrier);
L
Linus Torvalds 已提交
1350 1351
}

1352
static void status(struct seq_file *seq, struct mddev *mddev)
L
Linus Torvalds 已提交
1353
{
1354
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1355 1356 1357
	int i;

	seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1358
		   conf->raid_disks - mddev->degraded);
1359 1360
	rcu_read_lock();
	for (i = 0; i < conf->raid_disks; i++) {
1361
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
L
Linus Torvalds 已提交
1362
		seq_printf(seq, "%s",
1363 1364 1365
			   rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
	}
	rcu_read_unlock();
L
Linus Torvalds 已提交
1366 1367 1368 1369
	seq_printf(seq, "]");
}


1370
static void error(struct mddev *mddev, struct md_rdev *rdev)
L
Linus Torvalds 已提交
1371 1372
{
	char b[BDEVNAME_SIZE];
1373
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1374 1375 1376 1377 1378 1379 1380

	/*
	 * If it is not operational, then we have already marked it as dead
	 * else if it is the last working disks, ignore the error, let the
	 * next level up know.
	 * else mark the drive as failed
	 */
1381
	if (test_bit(In_sync, &rdev->flags)
1382
	    && (conf->raid_disks - mddev->degraded) == 1) {
L
Linus Torvalds 已提交
1383 1384
		/*
		 * Don't fail the drive, act as though we were just a
1385 1386 1387
		 * normal single drive.
		 * However don't try a recovery from this drive as
		 * it is very likely to fail.
L
Linus Torvalds 已提交
1388
		 */
1389
		conf->recovery_disabled = mddev->recovery_disabled;
L
Linus Torvalds 已提交
1390
		return;
1391
	}
1392
	set_bit(Blocked, &rdev->flags);
1393 1394 1395
	if (test_and_clear_bit(In_sync, &rdev->flags)) {
		unsigned long flags;
		spin_lock_irqsave(&conf->device_lock, flags);
L
Linus Torvalds 已提交
1396
		mddev->degraded++;
1397
		set_bit(Faulty, &rdev->flags);
1398
		spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
1399 1400 1401
		/*
		 * if recovery is running, make sure it aborts.
		 */
1402
		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1403 1404
	} else
		set_bit(Faulty, &rdev->flags);
1405
	set_bit(MD_CHANGE_DEVS, &mddev->flags);
1406 1407 1408
	printk(KERN_ALERT
	       "md/raid1:%s: Disk failure on %s, disabling device.\n"
	       "md/raid1:%s: Operation continuing on %d devices.\n",
N
NeilBrown 已提交
1409 1410
	       mdname(mddev), bdevname(rdev->bdev, b),
	       mdname(mddev), conf->raid_disks - mddev->degraded);
L
Linus Torvalds 已提交
1411 1412
}

1413
static void print_conf(struct r1conf *conf)
L
Linus Torvalds 已提交
1414 1415 1416
{
	int i;

N
NeilBrown 已提交
1417
	printk(KERN_DEBUG "RAID1 conf printout:\n");
L
Linus Torvalds 已提交
1418
	if (!conf) {
N
NeilBrown 已提交
1419
		printk(KERN_DEBUG "(!conf)\n");
L
Linus Torvalds 已提交
1420 1421
		return;
	}
N
NeilBrown 已提交
1422
	printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
L
Linus Torvalds 已提交
1423 1424
		conf->raid_disks);

1425
	rcu_read_lock();
L
Linus Torvalds 已提交
1426 1427
	for (i = 0; i < conf->raid_disks; i++) {
		char b[BDEVNAME_SIZE];
1428
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1429
		if (rdev)
N
NeilBrown 已提交
1430
			printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1431 1432 1433
			       i, !test_bit(In_sync, &rdev->flags),
			       !test_bit(Faulty, &rdev->flags),
			       bdevname(rdev->bdev,b));
L
Linus Torvalds 已提交
1434
	}
1435
	rcu_read_unlock();
L
Linus Torvalds 已提交
1436 1437
}

1438
static void close_sync(struct r1conf *conf)
L
Linus Torvalds 已提交
1439
{
1440 1441
	wait_barrier(conf);
	allow_barrier(conf);
L
Linus Torvalds 已提交
1442 1443 1444 1445 1446

	mempool_destroy(conf->r1buf_pool);
	conf->r1buf_pool = NULL;
}

1447
static int raid1_spare_active(struct mddev *mddev)
L
Linus Torvalds 已提交
1448 1449
{
	int i;
1450
	struct r1conf *conf = mddev->private;
1451 1452
	int count = 0;
	unsigned long flags;
L
Linus Torvalds 已提交
1453 1454 1455

	/*
	 * Find all failed disks within the RAID1 configuration 
1456 1457
	 * and mark them readable.
	 * Called under mddev lock, so rcu protection not needed.
L
Linus Torvalds 已提交
1458 1459
	 */
	for (i = 0; i < conf->raid_disks; i++) {
1460
		struct md_rdev *rdev = conf->mirrors[i].rdev;
1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479
		struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
		if (repl
		    && repl->recovery_offset == MaxSector
		    && !test_bit(Faulty, &repl->flags)
		    && !test_and_set_bit(In_sync, &repl->flags)) {
			/* replacement has just become active */
			if (!rdev ||
			    !test_and_clear_bit(In_sync, &rdev->flags))
				count++;
			if (rdev) {
				/* Replaced device not technically
				 * faulty, but we need to be sure
				 * it gets removed and never re-added
				 */
				set_bit(Faulty, &rdev->flags);
				sysfs_notify_dirent_safe(
					rdev->sysfs_state);
			}
		}
1480 1481
		if (rdev
		    && !test_bit(Faulty, &rdev->flags)
1482
		    && !test_and_set_bit(In_sync, &rdev->flags)) {
1483
			count++;
1484
			sysfs_notify_dirent_safe(rdev->sysfs_state);
L
Linus Torvalds 已提交
1485 1486
		}
	}
1487 1488 1489
	spin_lock_irqsave(&conf->device_lock, flags);
	mddev->degraded -= count;
	spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
1490 1491

	print_conf(conf);
1492
	return count;
L
Linus Torvalds 已提交
1493 1494 1495
}


1496
static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
L
Linus Torvalds 已提交
1497
{
1498
	struct r1conf *conf = mddev->private;
1499
	int err = -EEXIST;
1500
	int mirror = 0;
1501
	struct raid1_info *p;
1502
	int first = 0;
1503
	int last = conf->raid_disks - 1;
1504
	struct request_queue *q = bdev_get_queue(rdev->bdev);
L
Linus Torvalds 已提交
1505

1506 1507 1508
	if (mddev->recovery_disabled == conf->recovery_disabled)
		return -EBUSY;

1509 1510 1511
	if (rdev->raid_disk >= 0)
		first = last = rdev->raid_disk;

1512 1513 1514 1515 1516
	if (q->merge_bvec_fn) {
		set_bit(Unmerged, &rdev->flags);
		mddev->merge_check_needed = 1;
	}

1517 1518 1519
	for (mirror = first; mirror <= last; mirror++) {
		p = conf->mirrors+mirror;
		if (!p->rdev) {
L
Linus Torvalds 已提交
1520

1521 1522
			disk_stack_limits(mddev->gendisk, rdev->bdev,
					  rdev->data_offset << 9);
L
Linus Torvalds 已提交
1523 1524 1525

			p->head_position = 0;
			rdev->raid_disk = mirror;
1526
			err = 0;
1527 1528 1529 1530
			/* As all devices are equivalent, we don't need a full recovery
			 * if this was recently any drive of the array
			 */
			if (rdev->saved_raid_disk < 0)
1531
				conf->fullsync = 1;
1532
			rcu_assign_pointer(p->rdev, rdev);
L
Linus Torvalds 已提交
1533 1534
			break;
		}
1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546
		if (test_bit(WantReplacement, &p->rdev->flags) &&
		    p[conf->raid_disks].rdev == NULL) {
			/* Add this device as a replacement */
			clear_bit(In_sync, &rdev->flags);
			set_bit(Replacement, &rdev->flags);
			rdev->raid_disk = mirror;
			err = 0;
			conf->fullsync = 1;
			rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
			break;
		}
	}
1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559
	if (err == 0 && test_bit(Unmerged, &rdev->flags)) {
		/* Some requests might not have seen this new
		 * merge_bvec_fn.  We must wait for them to complete
		 * before merging the device fully.
		 * First we make sure any code which has tested
		 * our function has submitted the request, then
		 * we wait for all outstanding requests to complete.
		 */
		synchronize_sched();
		raise_barrier(conf);
		lower_barrier(conf);
		clear_bit(Unmerged, &rdev->flags);
	}
1560
	md_integrity_add_rdev(rdev, mddev);
S
Shaohua Li 已提交
1561 1562
	if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
L
Linus Torvalds 已提交
1563
	print_conf(conf);
1564
	return err;
L
Linus Torvalds 已提交
1565 1566
}

1567
static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
L
Linus Torvalds 已提交
1568
{
1569
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1570
	int err = 0;
1571
	int number = rdev->raid_disk;
1572
	struct raid1_info *p = conf->mirrors + number;
L
Linus Torvalds 已提交
1573

1574 1575 1576
	if (rdev != p->rdev)
		p = conf->mirrors + conf->raid_disks + number;

L
Linus Torvalds 已提交
1577
	print_conf(conf);
1578
	if (rdev == p->rdev) {
1579
		if (test_bit(In_sync, &rdev->flags) ||
L
Linus Torvalds 已提交
1580 1581 1582 1583
		    atomic_read(&rdev->nr_pending)) {
			err = -EBUSY;
			goto abort;
		}
N
NeilBrown 已提交
1584
		/* Only remove non-faulty devices if recovery
1585 1586 1587
		 * is not possible.
		 */
		if (!test_bit(Faulty, &rdev->flags) &&
1588
		    mddev->recovery_disabled != conf->recovery_disabled &&
1589 1590 1591 1592
		    mddev->degraded < conf->raid_disks) {
			err = -EBUSY;
			goto abort;
		}
L
Linus Torvalds 已提交
1593
		p->rdev = NULL;
1594
		synchronize_rcu();
L
Linus Torvalds 已提交
1595 1596 1597 1598
		if (atomic_read(&rdev->nr_pending)) {
			/* lost the race, try later */
			err = -EBUSY;
			p->rdev = rdev;
1599
			goto abort;
1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613
		} else if (conf->mirrors[conf->raid_disks + number].rdev) {
			/* We just removed a device that is being replaced.
			 * Move down the replacement.  We drain all IO before
			 * doing this to avoid confusion.
			 */
			struct md_rdev *repl =
				conf->mirrors[conf->raid_disks + number].rdev;
			raise_barrier(conf);
			clear_bit(Replacement, &repl->flags);
			p->rdev = repl;
			conf->mirrors[conf->raid_disks + number].rdev = NULL;
			lower_barrier(conf);
			clear_bit(WantReplacement, &rdev->flags);
		} else
1614
			clear_bit(WantReplacement, &rdev->flags);
1615
		err = md_integrity_register(mddev);
L
Linus Torvalds 已提交
1616 1617 1618 1619 1620 1621 1622 1623
	}
abort:

	print_conf(conf);
	return err;
}


1624
static void end_sync_read(struct bio *bio, int error)
L
Linus Torvalds 已提交
1625
{
1626
	struct r1bio *r1_bio = bio->bi_private;
L
Linus Torvalds 已提交
1627

1628
	update_head_pos(r1_bio->read_disk, r1_bio);
1629

L
Linus Torvalds 已提交
1630 1631 1632 1633 1634
	/*
	 * we have read a block, now it needs to be re-written,
	 * or re-read if the read failed.
	 * We don't do much here, just schedule handling by raid1d
	 */
1635
	if (test_bit(BIO_UPTODATE, &bio->bi_flags))
L
Linus Torvalds 已提交
1636
		set_bit(R1BIO_Uptodate, &r1_bio->state);
1637 1638 1639

	if (atomic_dec_and_test(&r1_bio->remaining))
		reschedule_retry(r1_bio);
L
Linus Torvalds 已提交
1640 1641
}

1642
static void end_sync_write(struct bio *bio, int error)
L
Linus Torvalds 已提交
1643 1644
{
	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1645
	struct r1bio *r1_bio = bio->bi_private;
1646
	struct mddev *mddev = r1_bio->mddev;
1647
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1648
	int mirror=0;
1649 1650
	sector_t first_bad;
	int bad_sectors;
L
Linus Torvalds 已提交
1651

1652 1653
	mirror = find_bio_disk(r1_bio, bio);

1654
	if (!uptodate) {
N
NeilBrown 已提交
1655
		sector_t sync_blocks = 0;
1656 1657 1658 1659
		sector_t s = r1_bio->sector;
		long sectors_to_go = r1_bio->sectors;
		/* make sure these bits doesn't get cleared. */
		do {
1660
			bitmap_end_sync(mddev->bitmap, s,
1661 1662 1663 1664
					&sync_blocks, 1);
			s += sync_blocks;
			sectors_to_go -= sync_blocks;
		} while (sectors_to_go > 0);
1665 1666
		set_bit(WriteErrorSeen,
			&conf->mirrors[mirror].rdev->flags);
1667 1668 1669 1670
		if (!test_and_set_bit(WantReplacement,
				      &conf->mirrors[mirror].rdev->flags))
			set_bit(MD_RECOVERY_NEEDED, &
				mddev->recovery);
1671
		set_bit(R1BIO_WriteError, &r1_bio->state);
1672 1673 1674
	} else if (is_badblock(conf->mirrors[mirror].rdev,
			       r1_bio->sector,
			       r1_bio->sectors,
1675 1676 1677 1678 1679 1680
			       &first_bad, &bad_sectors) &&
		   !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
				r1_bio->sector,
				r1_bio->sectors,
				&first_bad, &bad_sectors)
		)
1681
		set_bit(R1BIO_MadeGood, &r1_bio->state);
1682

L
Linus Torvalds 已提交
1683
	if (atomic_dec_and_test(&r1_bio->remaining)) {
1684
		int s = r1_bio->sectors;
1685 1686
		if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
		    test_bit(R1BIO_WriteError, &r1_bio->state))
1687 1688 1689 1690 1691
			reschedule_retry(r1_bio);
		else {
			put_buf(r1_bio);
			md_done_sync(mddev, s, uptodate);
		}
L
Linus Torvalds 已提交
1692 1693 1694
	}
}

1695
static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1696 1697 1698 1699 1700
			    int sectors, struct page *page, int rw)
{
	if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
		/* success */
		return 1;
1701
	if (rw == WRITE) {
1702
		set_bit(WriteErrorSeen, &rdev->flags);
1703 1704 1705 1706 1707
		if (!test_and_set_bit(WantReplacement,
				      &rdev->flags))
			set_bit(MD_RECOVERY_NEEDED, &
				rdev->mddev->recovery);
	}
1708 1709 1710 1711 1712 1713
	/* need to record an error - either for the block or the device */
	if (!rdev_set_badblocks(rdev, sector, sectors, 0))
		md_error(rdev->mddev, rdev);
	return 0;
}

1714
static int fix_sync_read_error(struct r1bio *r1_bio)
L
Linus Torvalds 已提交
1715
{
1716 1717 1718 1719 1720 1721 1722
	/* Try some synchronous reads of other devices to get
	 * good data, much like with normal read errors.  Only
	 * read into the pages we already have so we don't
	 * need to re-issue the read request.
	 * We don't need to freeze the array, because being in an
	 * active sync request, there is no normal IO, and
	 * no overlapping syncs.
1723 1724 1725
	 * We don't need to check is_badblock() again as we
	 * made sure that anything with a bad block in range
	 * will have bi_end_io clear.
1726
	 */
1727
	struct mddev *mddev = r1_bio->mddev;
1728
	struct r1conf *conf = mddev->private;
1729 1730 1731 1732 1733 1734 1735 1736 1737
	struct bio *bio = r1_bio->bios[r1_bio->read_disk];
	sector_t sect = r1_bio->sector;
	int sectors = r1_bio->sectors;
	int idx = 0;

	while(sectors) {
		int s = sectors;
		int d = r1_bio->read_disk;
		int success = 0;
1738
		struct md_rdev *rdev;
1739
		int start;
1740 1741 1742 1743 1744 1745 1746 1747 1748 1749

		if (s > (PAGE_SIZE>>9))
			s = PAGE_SIZE >> 9;
		do {
			if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
				/* No rcu protection needed here devices
				 * can only be removed when no resync is
				 * active, and resync is currently active
				 */
				rdev = conf->mirrors[d].rdev;
1750
				if (sync_page_io(rdev, sect, s<<9,
1751 1752 1753 1754 1755 1756 1757
						 bio->bi_io_vec[idx].bv_page,
						 READ, false)) {
					success = 1;
					break;
				}
			}
			d++;
1758
			if (d == conf->raid_disks * 2)
1759 1760 1761
				d = 0;
		} while (!success && d != r1_bio->read_disk);

1762
		if (!success) {
1763
			char b[BDEVNAME_SIZE];
1764 1765 1766 1767 1768 1769
			int abort = 0;
			/* Cannot read from anywhere, this block is lost.
			 * Record a bad block on each device.  If that doesn't
			 * work just disable and interrupt the recovery.
			 * Don't fail devices as that won't really help.
			 */
1770 1771 1772 1773 1774
			printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
			       " for block %llu\n",
			       mdname(mddev),
			       bdevname(bio->bi_bdev, b),
			       (unsigned long long)r1_bio->sector);
1775
			for (d = 0; d < conf->raid_disks * 2; d++) {
1776 1777 1778 1779 1780 1781 1782
				rdev = conf->mirrors[d].rdev;
				if (!rdev || test_bit(Faulty, &rdev->flags))
					continue;
				if (!rdev_set_badblocks(rdev, sect, s, 0))
					abort = 1;
			}
			if (abort) {
1783 1784
				conf->recovery_disabled =
					mddev->recovery_disabled;
1785 1786 1787 1788 1789 1790 1791 1792 1793 1794
				set_bit(MD_RECOVERY_INTR, &mddev->recovery);
				md_done_sync(mddev, r1_bio->sectors, 0);
				put_buf(r1_bio);
				return 0;
			}
			/* Try next page */
			sectors -= s;
			sect += s;
			idx++;
			continue;
1795
		}
1796 1797 1798 1799 1800

		start = d;
		/* write it back and re-read */
		while (d != r1_bio->read_disk) {
			if (d == 0)
1801
				d = conf->raid_disks * 2;
1802 1803 1804 1805
			d--;
			if (r1_bio->bios[d]->bi_end_io != end_sync_read)
				continue;
			rdev = conf->mirrors[d].rdev;
1806 1807 1808
			if (r1_sync_page_io(rdev, sect, s,
					    bio->bi_io_vec[idx].bv_page,
					    WRITE) == 0) {
1809 1810
				r1_bio->bios[d]->bi_end_io = NULL;
				rdev_dec_pending(rdev, mddev);
1811
			}
1812 1813 1814 1815
		}
		d = start;
		while (d != r1_bio->read_disk) {
			if (d == 0)
1816
				d = conf->raid_disks * 2;
1817 1818 1819 1820
			d--;
			if (r1_bio->bios[d]->bi_end_io != end_sync_read)
				continue;
			rdev = conf->mirrors[d].rdev;
1821 1822 1823
			if (r1_sync_page_io(rdev, sect, s,
					    bio->bi_io_vec[idx].bv_page,
					    READ) != 0)
1824
				atomic_add(s, &rdev->corrected_errors);
1825
		}
1826 1827 1828 1829
		sectors -= s;
		sect += s;
		idx ++;
	}
1830
	set_bit(R1BIO_Uptodate, &r1_bio->state);
1831
	set_bit(BIO_UPTODATE, &bio->bi_flags);
1832 1833 1834
	return 1;
}

1835
static int process_checks(struct r1bio *r1_bio)
1836 1837 1838 1839 1840 1841 1842 1843
{
	/* We have read all readable devices.  If we haven't
	 * got the block, then there is no hope left.
	 * If we have, then we want to do a comparison
	 * and skip the write if everything is the same.
	 * If any blocks failed to read, then we need to
	 * attempt an over-write
	 */
1844
	struct mddev *mddev = r1_bio->mddev;
1845
	struct r1conf *conf = mddev->private;
1846 1847
	int primary;
	int i;
1848
	int vcnt;
1849

1850
	for (primary = 0; primary < conf->raid_disks * 2; primary++)
1851 1852 1853 1854 1855 1856 1857
		if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
		    test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
			r1_bio->bios[primary]->bi_end_io = NULL;
			rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
			break;
		}
	r1_bio->read_disk = primary;
1858
	vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
1859
	for (i = 0; i < conf->raid_disks * 2; i++) {
1860 1861 1862 1863
		int j;
		struct bio *pbio = r1_bio->bios[primary];
		struct bio *sbio = r1_bio->bios[i];
		int size;
1864

1865 1866 1867 1868 1869 1870 1871 1872 1873 1874
		if (r1_bio->bios[i]->bi_end_io != end_sync_read)
			continue;

		if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
			for (j = vcnt; j-- ; ) {
				struct page *p, *s;
				p = pbio->bi_io_vec[j].bv_page;
				s = sbio->bi_io_vec[j].bv_page;
				if (memcmp(page_address(p),
					   page_address(s),
1875
					   sbio->bi_io_vec[j].bv_len))
1876
					break;
1877
			}
1878 1879 1880
		} else
			j = 0;
		if (j >= 0)
1881
			atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912
		if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
			      && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
			/* No need to write to this device. */
			sbio->bi_end_io = NULL;
			rdev_dec_pending(conf->mirrors[i].rdev, mddev);
			continue;
		}
		/* fixup the bio for reuse */
		sbio->bi_vcnt = vcnt;
		sbio->bi_size = r1_bio->sectors << 9;
		sbio->bi_idx = 0;
		sbio->bi_phys_segments = 0;
		sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
		sbio->bi_flags |= 1 << BIO_UPTODATE;
		sbio->bi_next = NULL;
		sbio->bi_sector = r1_bio->sector +
			conf->mirrors[i].rdev->data_offset;
		sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
		size = sbio->bi_size;
		for (j = 0; j < vcnt ; j++) {
			struct bio_vec *bi;
			bi = &sbio->bi_io_vec[j];
			bi->bv_offset = 0;
			if (size > PAGE_SIZE)
				bi->bv_len = PAGE_SIZE;
			else
				bi->bv_len = size;
			size -= PAGE_SIZE;
			memcpy(page_address(bi->bv_page),
			       page_address(pbio->bi_io_vec[j].bv_page),
			       PAGE_SIZE);
1913
		}
1914
	}
1915 1916 1917
	return 0;
}

1918
static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
1919
{
1920
	struct r1conf *conf = mddev->private;
1921
	int i;
1922
	int disks = conf->raid_disks * 2;
1923 1924 1925 1926 1927 1928 1929 1930
	struct bio *bio, *wbio;

	bio = r1_bio->bios[r1_bio->read_disk];

	if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
		/* ouch - failed to read all of that. */
		if (!fix_sync_read_error(r1_bio))
			return;
1931 1932 1933 1934

	if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
		if (process_checks(r1_bio) < 0)
			return;
1935 1936 1937
	/*
	 * schedule writes
	 */
L
Linus Torvalds 已提交
1938 1939 1940
	atomic_set(&r1_bio->remaining, 1);
	for (i = 0; i < disks ; i++) {
		wbio = r1_bio->bios[i];
1941 1942 1943 1944
		if (wbio->bi_end_io == NULL ||
		    (wbio->bi_end_io == end_sync_read &&
		     (i == r1_bio->read_disk ||
		      !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
L
Linus Torvalds 已提交
1945 1946
			continue;

1947 1948
		wbio->bi_rw = WRITE;
		wbio->bi_end_io = end_sync_write;
L
Linus Torvalds 已提交
1949 1950
		atomic_inc(&r1_bio->remaining);
		md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1951

L
Linus Torvalds 已提交
1952 1953 1954 1955
		generic_make_request(wbio);
	}

	if (atomic_dec_and_test(&r1_bio->remaining)) {
1956
		/* if we're here, all write(s) have completed, so clean up */
1957 1958 1959 1960 1961 1962 1963 1964
		int s = r1_bio->sectors;
		if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
		    test_bit(R1BIO_WriteError, &r1_bio->state))
			reschedule_retry(r1_bio);
		else {
			put_buf(r1_bio);
			md_done_sync(mddev, s, 1);
		}
L
Linus Torvalds 已提交
1965 1966 1967 1968 1969 1970 1971 1972
	}
}

/*
 * This is a kernel thread which:
 *
 *	1.	Retries failed read operations on working mirrors.
 *	2.	Updates the raid superblock when problems encounter.
1973
 *	3.	Performs writes following reads for array synchronising.
L
Linus Torvalds 已提交
1974 1975
 */

1976
static void fix_read_error(struct r1conf *conf, int read_disk,
1977 1978
			   sector_t sect, int sectors)
{
1979
	struct mddev *mddev = conf->mddev;
1980 1981 1982 1983 1984
	while(sectors) {
		int s = sectors;
		int d = read_disk;
		int success = 0;
		int start;
1985
		struct md_rdev *rdev;
1986 1987 1988 1989 1990 1991 1992 1993 1994 1995

		if (s > (PAGE_SIZE>>9))
			s = PAGE_SIZE >> 9;

		do {
			/* Note: no rcu protection needed here
			 * as this is synchronous in the raid1d thread
			 * which is the thread that might remove
			 * a device.  If raid1d ever becomes multi-threaded....
			 */
1996 1997 1998
			sector_t first_bad;
			int bad_sectors;

1999 2000
			rdev = conf->mirrors[d].rdev;
			if (rdev &&
2001 2002 2003
			    (test_bit(In_sync, &rdev->flags) ||
			     (!test_bit(Faulty, &rdev->flags) &&
			      rdev->recovery_offset >= sect + s)) &&
2004 2005
			    is_badblock(rdev, sect, s,
					&first_bad, &bad_sectors) == 0 &&
J
Jonathan Brassow 已提交
2006 2007
			    sync_page_io(rdev, sect, s<<9,
					 conf->tmppage, READ, false))
2008 2009 2010
				success = 1;
			else {
				d++;
2011
				if (d == conf->raid_disks * 2)
2012 2013 2014 2015 2016
					d = 0;
			}
		} while (!success && d != read_disk);

		if (!success) {
2017
			/* Cannot read from anywhere - mark it bad */
2018
			struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2019 2020
			if (!rdev_set_badblocks(rdev, sect, s, 0))
				md_error(mddev, rdev);
2021 2022 2023 2024 2025 2026
			break;
		}
		/* write it back and re-read */
		start = d;
		while (d != read_disk) {
			if (d==0)
2027
				d = conf->raid_disks * 2;
2028 2029 2030
			d--;
			rdev = conf->mirrors[d].rdev;
			if (rdev &&
2031 2032 2033
			    test_bit(In_sync, &rdev->flags))
				r1_sync_page_io(rdev, sect, s,
						conf->tmppage, WRITE);
2034 2035 2036 2037 2038
		}
		d = start;
		while (d != read_disk) {
			char b[BDEVNAME_SIZE];
			if (d==0)
2039
				d = conf->raid_disks * 2;
2040 2041 2042 2043
			d--;
			rdev = conf->mirrors[d].rdev;
			if (rdev &&
			    test_bit(In_sync, &rdev->flags)) {
2044 2045
				if (r1_sync_page_io(rdev, sect, s,
						    conf->tmppage, READ)) {
2046 2047
					atomic_add(s, &rdev->corrected_errors);
					printk(KERN_INFO
N
NeilBrown 已提交
2048
					       "md/raid1:%s: read error corrected "
2049 2050
					       "(%d sectors at %llu on %s)\n",
					       mdname(mddev), s,
2051 2052
					       (unsigned long long)(sect +
					           rdev->data_offset),
2053 2054 2055 2056 2057 2058 2059 2060 2061
					       bdevname(rdev->bdev, b));
				}
			}
		}
		sectors -= s;
		sect += s;
	}
}

2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080
static void bi_complete(struct bio *bio, int error)
{
	complete((struct completion *)bio->bi_private);
}

static int submit_bio_wait(int rw, struct bio *bio)
{
	struct completion event;
	rw |= REQ_SYNC;

	init_completion(&event);
	bio->bi_private = &event;
	bio->bi_end_io = bi_complete;
	submit_bio(rw, bio);
	wait_for_completion(&event);

	return test_bit(BIO_UPTODATE, &bio->bi_flags);
}

2081
static int narrow_write_error(struct r1bio *r1_bio, int i)
2082
{
2083
	struct mddev *mddev = r1_bio->mddev;
2084
	struct r1conf *conf = mddev->private;
2085
	struct md_rdev *rdev = conf->mirrors[i].rdev;
2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156
	int vcnt, idx;
	struct bio_vec *vec;

	/* bio has the data to be written to device 'i' where
	 * we just recently had a write error.
	 * We repeatedly clone the bio and trim down to one block,
	 * then try the write.  Where the write fails we record
	 * a bad block.
	 * It is conceivable that the bio doesn't exactly align with
	 * blocks.  We must handle this somehow.
	 *
	 * We currently own a reference on the rdev.
	 */

	int block_sectors;
	sector_t sector;
	int sectors;
	int sect_to_write = r1_bio->sectors;
	int ok = 1;

	if (rdev->badblocks.shift < 0)
		return 0;

	block_sectors = 1 << rdev->badblocks.shift;
	sector = r1_bio->sector;
	sectors = ((sector + block_sectors)
		   & ~(sector_t)(block_sectors - 1))
		- sector;

	if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
		vcnt = r1_bio->behind_page_count;
		vec = r1_bio->behind_bvecs;
		idx = 0;
		while (vec[idx].bv_page == NULL)
			idx++;
	} else {
		vcnt = r1_bio->master_bio->bi_vcnt;
		vec = r1_bio->master_bio->bi_io_vec;
		idx = r1_bio->master_bio->bi_idx;
	}
	while (sect_to_write) {
		struct bio *wbio;
		if (sectors > sect_to_write)
			sectors = sect_to_write;
		/* Write at 'sector' for 'sectors'*/

		wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
		memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
		wbio->bi_sector = r1_bio->sector;
		wbio->bi_rw = WRITE;
		wbio->bi_vcnt = vcnt;
		wbio->bi_size = r1_bio->sectors << 9;
		wbio->bi_idx = idx;

		md_trim_bio(wbio, sector - r1_bio->sector, sectors);
		wbio->bi_sector += rdev->data_offset;
		wbio->bi_bdev = rdev->bdev;
		if (submit_bio_wait(WRITE, wbio) == 0)
			/* failure! */
			ok = rdev_set_badblocks(rdev, sector,
						sectors, 0)
				&& ok;

		bio_put(wbio);
		sect_to_write -= sectors;
		sector += sectors;
		sectors = block_sectors;
	}
	return ok;
}

2157
static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2158 2159 2160
{
	int m;
	int s = r1_bio->sectors;
2161
	for (m = 0; m < conf->raid_disks * 2 ; m++) {
2162
		struct md_rdev *rdev = conf->mirrors[m].rdev;
2163 2164 2165 2166 2167
		struct bio *bio = r1_bio->bios[m];
		if (bio->bi_end_io == NULL)
			continue;
		if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
		    test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2168
			rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179
		}
		if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
		    test_bit(R1BIO_WriteError, &r1_bio->state)) {
			if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
				md_error(conf->mddev, rdev);
		}
	}
	put_buf(r1_bio);
	md_done_sync(conf->mddev, s, 1);
}

2180
static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2181 2182
{
	int m;
2183
	for (m = 0; m < conf->raid_disks * 2 ; m++)
2184
		if (r1_bio->bios[m] == IO_MADE_GOOD) {
2185
			struct md_rdev *rdev = conf->mirrors[m].rdev;
2186 2187
			rdev_clear_badblocks(rdev,
					     r1_bio->sector,
2188
					     r1_bio->sectors, 0);
2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208
			rdev_dec_pending(rdev, conf->mddev);
		} else if (r1_bio->bios[m] != NULL) {
			/* This drive got a write error.  We need to
			 * narrow down and record precise write
			 * errors.
			 */
			if (!narrow_write_error(r1_bio, m)) {
				md_error(conf->mddev,
					 conf->mirrors[m].rdev);
				/* an I/O failed, we can't clear the bitmap */
				set_bit(R1BIO_Degraded, &r1_bio->state);
			}
			rdev_dec_pending(conf->mirrors[m].rdev,
					 conf->mddev);
		}
	if (test_bit(R1BIO_WriteError, &r1_bio->state))
		close_write(r1_bio);
	raid_end_bio_io(r1_bio);
}

2209
static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2210 2211 2212
{
	int disk;
	int max_sectors;
2213
	struct mddev *mddev = conf->mddev;
2214 2215
	struct bio *bio;
	char b[BDEVNAME_SIZE];
2216
	struct md_rdev *rdev;
2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233

	clear_bit(R1BIO_ReadError, &r1_bio->state);
	/* we got a read error. Maybe the drive is bad.  Maybe just
	 * the block and we can fix it.
	 * We freeze all other IO, and try reading the block from
	 * other devices.  When we find one, we re-write
	 * and check it that fixes the read error.
	 * This is all done synchronously while the array is
	 * frozen
	 */
	if (mddev->ro == 0) {
		freeze_array(conf);
		fix_read_error(conf, r1_bio->read_disk,
			       r1_bio->sector, r1_bio->sectors);
		unfreeze_array(conf);
	} else
		md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
2234
	rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev);
2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299

	bio = r1_bio->bios[r1_bio->read_disk];
	bdevname(bio->bi_bdev, b);
read_more:
	disk = read_balance(conf, r1_bio, &max_sectors);
	if (disk == -1) {
		printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
		       " read error for block %llu\n",
		       mdname(mddev), b, (unsigned long long)r1_bio->sector);
		raid_end_bio_io(r1_bio);
	} else {
		const unsigned long do_sync
			= r1_bio->master_bio->bi_rw & REQ_SYNC;
		if (bio) {
			r1_bio->bios[r1_bio->read_disk] =
				mddev->ro ? IO_BLOCKED : NULL;
			bio_put(bio);
		}
		r1_bio->read_disk = disk;
		bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
		md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
		r1_bio->bios[r1_bio->read_disk] = bio;
		rdev = conf->mirrors[disk].rdev;
		printk_ratelimited(KERN_ERR
				   "md/raid1:%s: redirecting sector %llu"
				   " to other mirror: %s\n",
				   mdname(mddev),
				   (unsigned long long)r1_bio->sector,
				   bdevname(rdev->bdev, b));
		bio->bi_sector = r1_bio->sector + rdev->data_offset;
		bio->bi_bdev = rdev->bdev;
		bio->bi_end_io = raid1_end_read_request;
		bio->bi_rw = READ | do_sync;
		bio->bi_private = r1_bio;
		if (max_sectors < r1_bio->sectors) {
			/* Drat - have to split this up more */
			struct bio *mbio = r1_bio->master_bio;
			int sectors_handled = (r1_bio->sector + max_sectors
					       - mbio->bi_sector);
			r1_bio->sectors = max_sectors;
			spin_lock_irq(&conf->device_lock);
			if (mbio->bi_phys_segments == 0)
				mbio->bi_phys_segments = 2;
			else
				mbio->bi_phys_segments++;
			spin_unlock_irq(&conf->device_lock);
			generic_make_request(bio);
			bio = NULL;

			r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);

			r1_bio->master_bio = mbio;
			r1_bio->sectors = (mbio->bi_size >> 9)
					  - sectors_handled;
			r1_bio->state = 0;
			set_bit(R1BIO_ReadError, &r1_bio->state);
			r1_bio->mddev = mddev;
			r1_bio->sector = mbio->bi_sector + sectors_handled;

			goto read_more;
		} else
			generic_make_request(bio);
	}
}

S
Shaohua Li 已提交
2300
static void raid1d(struct md_thread *thread)
L
Linus Torvalds 已提交
2301
{
S
Shaohua Li 已提交
2302
	struct mddev *mddev = thread->mddev;
2303
	struct r1bio *r1_bio;
L
Linus Torvalds 已提交
2304
	unsigned long flags;
2305
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
2306
	struct list_head *head = &conf->retry_list;
2307
	struct blk_plug plug;
L
Linus Torvalds 已提交
2308 2309

	md_check_recovery(mddev);
2310 2311

	blk_start_plug(&plug);
L
Linus Torvalds 已提交
2312
	for (;;) {
2313

2314
		flush_pending_writes(conf);
2315

2316 2317 2318
		spin_lock_irqsave(&conf->device_lock, flags);
		if (list_empty(head)) {
			spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
2319
			break;
2320
		}
2321
		r1_bio = list_entry(head->prev, struct r1bio, retry_list);
L
Linus Torvalds 已提交
2322
		list_del(head->prev);
2323
		conf->nr_queued--;
L
Linus Torvalds 已提交
2324 2325 2326
		spin_unlock_irqrestore(&conf->device_lock, flags);

		mddev = r1_bio->mddev;
2327
		conf = mddev->private;
2328
		if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2329
			if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2330 2331 2332
			    test_bit(R1BIO_WriteError, &r1_bio->state))
				handle_sync_write_finished(conf, r1_bio);
			else
2333
				sync_request_write(mddev, r1_bio);
2334
		} else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2335 2336 2337 2338 2339
			   test_bit(R1BIO_WriteError, &r1_bio->state))
			handle_write_finished(conf, r1_bio);
		else if (test_bit(R1BIO_ReadError, &r1_bio->state))
			handle_read_error(conf, r1_bio);
		else
2340 2341 2342 2343
			/* just a partial read to be scheduled from separate
			 * context
			 */
			generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2344

N
NeilBrown 已提交
2345
		cond_resched();
2346 2347
		if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
			md_check_recovery(mddev);
L
Linus Torvalds 已提交
2348
	}
2349
	blk_finish_plug(&plug);
L
Linus Torvalds 已提交
2350 2351 2352
}


2353
static int init_resync(struct r1conf *conf)
L
Linus Torvalds 已提交
2354 2355 2356 2357
{
	int buffs;

	buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2358
	BUG_ON(conf->r1buf_pool);
L
Linus Torvalds 已提交
2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376
	conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
					  conf->poolinfo);
	if (!conf->r1buf_pool)
		return -ENOMEM;
	conf->next_resync = 0;
	return 0;
}

/*
 * perform a "sync" on one "block"
 *
 * We need to make sure that no normal I/O request - particularly write
 * requests - conflict with active sync requests.
 *
 * This is achieved by tracking pending requests and a 'barrier' concept
 * that can be installed to exclude normal IO requests.
 */

2377
static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
L
Linus Torvalds 已提交
2378
{
2379
	struct r1conf *conf = mddev->private;
2380
	struct r1bio *r1_bio;
L
Linus Torvalds 已提交
2381 2382
	struct bio *bio;
	sector_t max_sector, nr_sectors;
2383
	int disk = -1;
L
Linus Torvalds 已提交
2384
	int i;
2385 2386
	int wonly = -1;
	int write_targets = 0, read_targets = 0;
N
NeilBrown 已提交
2387
	sector_t sync_blocks;
2388
	int still_degraded = 0;
2389 2390
	int good_sectors = RESYNC_SECTORS;
	int min_bad = 0; /* number of sectors that are bad in all devices */
L
Linus Torvalds 已提交
2391 2392 2393

	if (!conf->r1buf_pool)
		if (init_resync(conf))
2394
			return 0;
L
Linus Torvalds 已提交
2395

A
Andre Noll 已提交
2396
	max_sector = mddev->dev_sectors;
L
Linus Torvalds 已提交
2397
	if (sector_nr >= max_sector) {
2398 2399 2400 2401 2402
		/* If we aborted, we need to abort the
		 * sync on the 'current' bitmap chunk (there will
		 * only be one in raid1 resync.
		 * We can find the current addess in mddev->curr_resync
		 */
2403 2404
		if (mddev->curr_resync < max_sector) /* aborted */
			bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2405
						&sync_blocks, 1);
2406
		else /* completed sync */
2407
			conf->fullsync = 0;
2408 2409

		bitmap_close_sync(mddev->bitmap);
L
Linus Torvalds 已提交
2410 2411 2412 2413
		close_sync(conf);
		return 0;
	}

2414 2415
	if (mddev->bitmap == NULL &&
	    mddev->recovery_cp == MaxSector &&
2416
	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2417 2418 2419 2420
	    conf->fullsync == 0) {
		*skipped = 1;
		return max_sector - sector_nr;
	}
2421 2422 2423
	/* before building a request, check if we can skip these blocks..
	 * This call the bitmap_start_sync doesn't actually record anything
	 */
2424
	if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2425
	    !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2426 2427 2428 2429
		/* We can skip this block, and probably several more */
		*skipped = 1;
		return sync_blocks;
	}
L
Linus Torvalds 已提交
2430
	/*
2431 2432 2433
	 * If there is non-resync activity waiting for a turn,
	 * and resync is going fast enough,
	 * then let it though before starting on this new sync request.
L
Linus Torvalds 已提交
2434
	 */
2435
	if (!go_faster && conf->nr_waiting)
L
Linus Torvalds 已提交
2436
		msleep_interruptible(1000);
2437

N
NeilBrown 已提交
2438
	bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2439
	r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2440 2441 2442
	raise_barrier(conf);

	conf->next_resync = sector_nr;
L
Linus Torvalds 已提交
2443

2444
	rcu_read_lock();
L
Linus Torvalds 已提交
2445
	/*
2446 2447 2448 2449 2450 2451
	 * If we get a correctably read error during resync or recovery,
	 * we might want to read from a different device.  So we
	 * flag all drives that could conceivably be read from for READ,
	 * and any others (which will be non-In_sync devices) for WRITE.
	 * If a read fails, we try reading from something else for which READ
	 * is OK.
L
Linus Torvalds 已提交
2452 2453 2454 2455
	 */

	r1_bio->mddev = mddev;
	r1_bio->sector = sector_nr;
2456
	r1_bio->state = 0;
L
Linus Torvalds 已提交
2457 2458
	set_bit(R1BIO_IsSync, &r1_bio->state);

2459
	for (i = 0; i < conf->raid_disks * 2; i++) {
2460
		struct md_rdev *rdev;
L
Linus Torvalds 已提交
2461 2462 2463 2464
		bio = r1_bio->bios[i];

		/* take from bio_init */
		bio->bi_next = NULL;
2465
		bio->bi_flags &= ~(BIO_POOL_MASK-1);
L
Linus Torvalds 已提交
2466
		bio->bi_flags |= 1 << BIO_UPTODATE;
2467
		bio->bi_rw = READ;
L
Linus Torvalds 已提交
2468 2469 2470 2471 2472 2473 2474
		bio->bi_vcnt = 0;
		bio->bi_idx = 0;
		bio->bi_phys_segments = 0;
		bio->bi_size = 0;
		bio->bi_end_io = NULL;
		bio->bi_private = NULL;

2475 2476
		rdev = rcu_dereference(conf->mirrors[i].rdev);
		if (rdev == NULL ||
2477
		    test_bit(Faulty, &rdev->flags)) {
2478 2479
			if (i < conf->raid_disks)
				still_degraded = 1;
2480
		} else if (!test_bit(In_sync, &rdev->flags)) {
L
Linus Torvalds 已提交
2481 2482 2483
			bio->bi_rw = WRITE;
			bio->bi_end_io = end_sync_write;
			write_targets ++;
2484 2485
		} else {
			/* may need to read from here */
2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510
			sector_t first_bad = MaxSector;
			int bad_sectors;

			if (is_badblock(rdev, sector_nr, good_sectors,
					&first_bad, &bad_sectors)) {
				if (first_bad > sector_nr)
					good_sectors = first_bad - sector_nr;
				else {
					bad_sectors -= (sector_nr - first_bad);
					if (min_bad == 0 ||
					    min_bad > bad_sectors)
						min_bad = bad_sectors;
				}
			}
			if (sector_nr < first_bad) {
				if (test_bit(WriteMostly, &rdev->flags)) {
					if (wonly < 0)
						wonly = i;
				} else {
					if (disk < 0)
						disk = i;
				}
				bio->bi_rw = READ;
				bio->bi_end_io = end_sync_read;
				read_targets++;
2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522
			} else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
				test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
				!test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
				/*
				 * The device is suitable for reading (InSync),
				 * but has bad block(s) here. Let's try to correct them,
				 * if we are doing resync or repair. Otherwise, leave
				 * this device alone for this sync request.
				 */
				bio->bi_rw = WRITE;
				bio->bi_end_io = end_sync_write;
				write_targets++;
2523 2524
			}
		}
2525 2526 2527 2528 2529 2530
		if (bio->bi_end_io) {
			atomic_inc(&rdev->nr_pending);
			bio->bi_sector = sector_nr + rdev->data_offset;
			bio->bi_bdev = rdev->bdev;
			bio->bi_private = r1_bio;
		}
L
Linus Torvalds 已提交
2531
	}
2532 2533 2534 2535
	rcu_read_unlock();
	if (disk < 0)
		disk = wonly;
	r1_bio->read_disk = disk;
2536

2537 2538 2539 2540 2541
	if (read_targets == 0 && min_bad > 0) {
		/* These sectors are bad on all InSync devices, so we
		 * need to mark them bad on all write targets
		 */
		int ok = 1;
2542
		for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2543
			if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2544
				struct md_rdev *rdev = conf->mirrors[i].rdev;
2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571
				ok = rdev_set_badblocks(rdev, sector_nr,
							min_bad, 0
					) && ok;
			}
		set_bit(MD_CHANGE_DEVS, &mddev->flags);
		*skipped = 1;
		put_buf(r1_bio);

		if (!ok) {
			/* Cannot record the badblocks, so need to
			 * abort the resync.
			 * If there are multiple read targets, could just
			 * fail the really bad ones ???
			 */
			conf->recovery_disabled = mddev->recovery_disabled;
			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
			return 0;
		} else
			return min_bad;

	}
	if (min_bad > 0 && min_bad < good_sectors) {
		/* only resync enough to reach the next bad->good
		 * transition */
		good_sectors = min_bad;
	}

2572 2573 2574 2575 2576
	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
		/* extra read targets are also write targets */
		write_targets += read_targets-1;

	if (write_targets == 0 || read_targets == 0) {
L
Linus Torvalds 已提交
2577 2578 2579
		/* There is nowhere to write, so all non-sync
		 * drives must be failed - so we are finished
		 */
2580 2581 2582 2583
		sector_t rv;
		if (min_bad > 0)
			max_sector = sector_nr + min_bad;
		rv = max_sector - sector_nr;
2584
		*skipped = 1;
L
Linus Torvalds 已提交
2585 2586 2587 2588
		put_buf(r1_bio);
		return rv;
	}

2589 2590
	if (max_sector > mddev->resync_max)
		max_sector = mddev->resync_max; /* Don't do IO beyond here */
2591 2592
	if (max_sector > sector_nr + good_sectors)
		max_sector = sector_nr + good_sectors;
L
Linus Torvalds 已提交
2593
	nr_sectors = 0;
2594
	sync_blocks = 0;
L
Linus Torvalds 已提交
2595 2596 2597 2598 2599 2600 2601
	do {
		struct page *page;
		int len = PAGE_SIZE;
		if (sector_nr + (len>>9) > max_sector)
			len = (max_sector - sector_nr) << 9;
		if (len == 0)
			break;
2602 2603
		if (sync_blocks == 0) {
			if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2604 2605 2606
					       &sync_blocks, still_degraded) &&
			    !conf->fullsync &&
			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2607
				break;
2608
			BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2609
			if ((len >> 9) > sync_blocks)
2610
				len = sync_blocks<<9;
2611
		}
2612

2613
		for (i = 0 ; i < conf->raid_disks * 2; i++) {
L
Linus Torvalds 已提交
2614 2615
			bio = r1_bio->bios[i];
			if (bio->bi_end_io) {
2616
				page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
L
Linus Torvalds 已提交
2617 2618
				if (bio_add_page(bio, page, len, 0) == 0) {
					/* stop here */
2619
					bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
L
Linus Torvalds 已提交
2620 2621 2622
					while (i > 0) {
						i--;
						bio = r1_bio->bios[i];
2623 2624
						if (bio->bi_end_io==NULL)
							continue;
L
Linus Torvalds 已提交
2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635
						/* remove last page from this bio */
						bio->bi_vcnt--;
						bio->bi_size -= len;
						bio->bi_flags &= ~(1<< BIO_SEG_VALID);
					}
					goto bio_full;
				}
			}
		}
		nr_sectors += len>>9;
		sector_nr += len>>9;
2636
		sync_blocks -= (len>>9);
L
Linus Torvalds 已提交
2637 2638 2639 2640
	} while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
 bio_full:
	r1_bio->sectors = nr_sectors;

2641 2642 2643 2644 2645
	/* For a user-requested sync, we read all readable devices and do a
	 * compare
	 */
	if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
		atomic_set(&r1_bio->remaining, read_targets);
2646
		for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2647 2648
			bio = r1_bio->bios[i];
			if (bio->bi_end_io == end_sync_read) {
2649
				read_targets--;
2650
				md_sync_acct(bio->bi_bdev, nr_sectors);
2651 2652 2653 2654 2655 2656
				generic_make_request(bio);
			}
		}
	} else {
		atomic_set(&r1_bio->remaining, 1);
		bio = r1_bio->bios[r1_bio->read_disk];
2657
		md_sync_acct(bio->bi_bdev, nr_sectors);
2658
		generic_make_request(bio);
L
Linus Torvalds 已提交
2659

2660
	}
L
Linus Torvalds 已提交
2661 2662 2663
	return nr_sectors;
}

2664
static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2665 2666 2667 2668 2669 2670 2671
{
	if (sectors)
		return sectors;

	return mddev->dev_sectors;
}

2672
static struct r1conf *setup_conf(struct mddev *mddev)
L
Linus Torvalds 已提交
2673
{
2674
	struct r1conf *conf;
2675
	int i;
2676
	struct raid1_info *disk;
2677
	struct md_rdev *rdev;
2678
	int err = -ENOMEM;
L
Linus Torvalds 已提交
2679

2680
	conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
L
Linus Torvalds 已提交
2681
	if (!conf)
2682
		goto abort;
L
Linus Torvalds 已提交
2683

2684
	conf->mirrors = kzalloc(sizeof(struct raid1_info)
2685
				* mddev->raid_disks * 2,
L
Linus Torvalds 已提交
2686 2687
				 GFP_KERNEL);
	if (!conf->mirrors)
2688
		goto abort;
L
Linus Torvalds 已提交
2689

2690 2691
	conf->tmppage = alloc_page(GFP_KERNEL);
	if (!conf->tmppage)
2692
		goto abort;
2693

2694
	conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
L
Linus Torvalds 已提交
2695
	if (!conf->poolinfo)
2696
		goto abort;
2697
	conf->poolinfo->raid_disks = mddev->raid_disks * 2;
L
Linus Torvalds 已提交
2698 2699 2700 2701
	conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
					  r1bio_pool_free,
					  conf->poolinfo);
	if (!conf->r1bio_pool)
2702 2703
		goto abort;

2704
	conf->poolinfo->mddev = mddev;
L
Linus Torvalds 已提交
2705

2706
	err = -EINVAL;
2707
	spin_lock_init(&conf->device_lock);
N
NeilBrown 已提交
2708
	rdev_for_each(rdev, mddev) {
2709
		struct request_queue *q;
2710
		int disk_idx = rdev->raid_disk;
L
Linus Torvalds 已提交
2711 2712 2713
		if (disk_idx >= mddev->raid_disks
		    || disk_idx < 0)
			continue;
2714
		if (test_bit(Replacement, &rdev->flags))
2715
			disk = conf->mirrors + mddev->raid_disks + disk_idx;
2716 2717
		else
			disk = conf->mirrors + disk_idx;
L
Linus Torvalds 已提交
2718

2719 2720
		if (disk->rdev)
			goto abort;
L
Linus Torvalds 已提交
2721
		disk->rdev = rdev;
2722 2723 2724
		q = bdev_get_queue(rdev->bdev);
		if (q->merge_bvec_fn)
			mddev->merge_check_needed = 1;
L
Linus Torvalds 已提交
2725 2726

		disk->head_position = 0;
2727
		disk->seq_start = MaxSector;
L
Linus Torvalds 已提交
2728 2729 2730 2731 2732 2733
	}
	conf->raid_disks = mddev->raid_disks;
	conf->mddev = mddev;
	INIT_LIST_HEAD(&conf->retry_list);

	spin_lock_init(&conf->resync_lock);
2734
	init_waitqueue_head(&conf->wait_barrier);
L
Linus Torvalds 已提交
2735

2736
	bio_list_init(&conf->pending_bio_list);
2737
	conf->pending_count = 0;
2738
	conf->recovery_disabled = mddev->recovery_disabled - 1;
2739

2740
	err = -EIO;
2741
	for (i = 0; i < conf->raid_disks * 2; i++) {
L
Linus Torvalds 已提交
2742 2743 2744

		disk = conf->mirrors + i;

2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759
		if (i < conf->raid_disks &&
		    disk[conf->raid_disks].rdev) {
			/* This slot has a replacement. */
			if (!disk->rdev) {
				/* No original, just make the replacement
				 * a recovering spare
				 */
				disk->rdev =
					disk[conf->raid_disks].rdev;
				disk[conf->raid_disks].rdev = NULL;
			} else if (!test_bit(In_sync, &disk->rdev->flags))
				/* Original is not in_sync - bad */
				goto abort;
		}

2760 2761
		if (!disk->rdev ||
		    !test_bit(In_sync, &disk->rdev->flags)) {
L
Linus Torvalds 已提交
2762
			disk->head_position = 0;
2763 2764
			if (disk->rdev &&
			    (disk->rdev->saved_raid_disk < 0))
2765
				conf->fullsync = 1;
2766
		}
L
Linus Torvalds 已提交
2767
	}
2768 2769

	err = -ENOMEM;
2770
	conf->thread = md_register_thread(raid1d, mddev, "raid1");
2771 2772
	if (!conf->thread) {
		printk(KERN_ERR
N
NeilBrown 已提交
2773
		       "md/raid1:%s: couldn't allocate thread\n",
2774 2775
		       mdname(mddev));
		goto abort;
2776
	}
L
Linus Torvalds 已提交
2777

2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791
	return conf;

 abort:
	if (conf) {
		if (conf->r1bio_pool)
			mempool_destroy(conf->r1bio_pool);
		kfree(conf->mirrors);
		safe_put_page(conf->tmppage);
		kfree(conf->poolinfo);
		kfree(conf);
	}
	return ERR_PTR(err);
}

2792
static int stop(struct mddev *mddev);
2793
static int run(struct mddev *mddev)
2794
{
2795
	struct r1conf *conf;
2796
	int i;
2797
	struct md_rdev *rdev;
2798
	int ret;
S
Shaohua Li 已提交
2799
	bool discard_supported = false;
2800 2801

	if (mddev->level != 1) {
N
NeilBrown 已提交
2802
		printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2803 2804 2805 2806
		       mdname(mddev), mddev->level);
		return -EIO;
	}
	if (mddev->reshape_position != MaxSector) {
N
NeilBrown 已提交
2807
		printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2808 2809 2810
		       mdname(mddev));
		return -EIO;
	}
L
Linus Torvalds 已提交
2811
	/*
2812 2813 2814
	 * copy the already verified devices into our private RAID1
	 * bookkeeping area. [whatever we allocate in run(),
	 * should be freed in stop()]
L
Linus Torvalds 已提交
2815
	 */
2816 2817 2818 2819
	if (mddev->private == NULL)
		conf = setup_conf(mddev);
	else
		conf = mddev->private;
L
Linus Torvalds 已提交
2820

2821 2822
	if (IS_ERR(conf))
		return PTR_ERR(conf);
L
Linus Torvalds 已提交
2823

2824 2825 2826
	if (mddev->queue)
		blk_queue_max_write_same_sectors(mddev->queue,
						 mddev->chunk_sectors);
N
NeilBrown 已提交
2827
	rdev_for_each(rdev, mddev) {
2828 2829
		if (!mddev->gendisk)
			continue;
2830 2831
		disk_stack_limits(mddev->gendisk, rdev->bdev,
				  rdev->data_offset << 9);
S
Shaohua Li 已提交
2832 2833
		if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
			discard_supported = true;
L
Linus Torvalds 已提交
2834
	}
2835

2836 2837 2838 2839 2840 2841 2842 2843 2844 2845
	mddev->degraded = 0;
	for (i=0; i < conf->raid_disks; i++)
		if (conf->mirrors[i].rdev == NULL ||
		    !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
		    test_bit(Faulty, &conf->mirrors[i].rdev->flags))
			mddev->degraded++;

	if (conf->raid_disks - mddev->degraded == 1)
		mddev->recovery_cp = MaxSector;

2846
	if (mddev->recovery_cp != MaxSector)
N
NeilBrown 已提交
2847
		printk(KERN_NOTICE "md/raid1:%s: not clean"
2848 2849
		       " -- starting background reconstruction\n",
		       mdname(mddev));
L
Linus Torvalds 已提交
2850
	printk(KERN_INFO 
N
NeilBrown 已提交
2851
		"md/raid1:%s: active with %d out of %d mirrors\n",
L
Linus Torvalds 已提交
2852 2853
		mdname(mddev), mddev->raid_disks - mddev->degraded, 
		mddev->raid_disks);
2854

L
Linus Torvalds 已提交
2855 2856 2857
	/*
	 * Ok, everything is just fine now
	 */
2858 2859 2860 2861
	mddev->thread = conf->thread;
	conf->thread = NULL;
	mddev->private = conf;

2862
	md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
L
Linus Torvalds 已提交
2863

2864 2865 2866
	if (mddev->queue) {
		mddev->queue->backing_dev_info.congested_fn = raid1_congested;
		mddev->queue->backing_dev_info.congested_data = mddev;
2867
		blk_queue_merge_bvec(mddev->queue, raid1_mergeable_bvec);
S
Shaohua Li 已提交
2868 2869 2870 2871 2872 2873 2874

		if (discard_supported)
			queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
						mddev->queue);
		else
			queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
						  mddev->queue);
2875
	}
2876 2877 2878 2879 2880

	ret =  md_integrity_register(mddev);
	if (ret)
		stop(mddev);
	return ret;
L
Linus Torvalds 已提交
2881 2882
}

2883
static int stop(struct mddev *mddev)
L
Linus Torvalds 已提交
2884
{
2885
	struct r1conf *conf = mddev->private;
2886 2887 2888
	struct bitmap *bitmap = mddev->bitmap;

	/* wait for behind writes to complete */
2889
	if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
N
NeilBrown 已提交
2890 2891
		printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
		       mdname(mddev));
2892
		/* need to kick something here to make sure I/O goes? */
2893 2894
		wait_event(bitmap->behind_wait,
			   atomic_read(&bitmap->behind_writes) == 0);
2895
	}
L
Linus Torvalds 已提交
2896

2897 2898 2899
	raise_barrier(conf);
	lower_barrier(conf);

2900
	md_unregister_thread(&mddev->thread);
L
Linus Torvalds 已提交
2901 2902
	if (conf->r1bio_pool)
		mempool_destroy(conf->r1bio_pool);
2903 2904
	kfree(conf->mirrors);
	kfree(conf->poolinfo);
L
Linus Torvalds 已提交
2905 2906 2907 2908 2909
	kfree(conf);
	mddev->private = NULL;
	return 0;
}

2910
static int raid1_resize(struct mddev *mddev, sector_t sectors)
L
Linus Torvalds 已提交
2911 2912 2913 2914 2915 2916 2917 2918
{
	/* no resync is happening, and there is enough space
	 * on all devices, so we can resize.
	 * We need to make sure resync covers any new space.
	 * If the array is shrinking we should possibly wait until
	 * any io in the removed space completes, but it hardly seems
	 * worth it.
	 */
2919 2920 2921
	sector_t newsize = raid1_size(mddev, sectors, 0);
	if (mddev->external_size &&
	    mddev->array_sectors > newsize)
D
Dan Williams 已提交
2922
		return -EINVAL;
2923 2924 2925 2926 2927 2928
	if (mddev->bitmap) {
		int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0);
		if (ret)
			return ret;
	}
	md_set_array_sectors(mddev, newsize);
2929
	set_capacity(mddev->gendisk, mddev->array_sectors);
2930
	revalidate_disk(mddev->gendisk);
D
Dan Williams 已提交
2931
	if (sectors > mddev->dev_sectors &&
2932
	    mddev->recovery_cp > mddev->dev_sectors) {
A
Andre Noll 已提交
2933
		mddev->recovery_cp = mddev->dev_sectors;
L
Linus Torvalds 已提交
2934 2935
		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
	}
D
Dan Williams 已提交
2936
	mddev->dev_sectors = sectors;
2937
	mddev->resync_max_sectors = sectors;
L
Linus Torvalds 已提交
2938 2939 2940
	return 0;
}

2941
static int raid1_reshape(struct mddev *mddev)
L
Linus Torvalds 已提交
2942 2943 2944 2945 2946 2947 2948 2949
{
	/* We need to:
	 * 1/ resize the r1bio_pool
	 * 2/ resize conf->mirrors
	 *
	 * We allocate a new r1bio_pool if we can.
	 * Then raise a device barrier and wait until all IO stops.
	 * Then resize conf->mirrors and swap in the new r1bio pool.
2950 2951 2952
	 *
	 * At the same time, we "pack" the devices so that all the missing
	 * devices have the higher raid_disk numbers.
L
Linus Torvalds 已提交
2953 2954 2955
	 */
	mempool_t *newpool, *oldpool;
	struct pool_info *newpoolinfo;
2956
	struct raid1_info *newmirrors;
2957
	struct r1conf *conf = mddev->private;
2958
	int cnt, raid_disks;
2959
	unsigned long flags;
2960
	int d, d2, err;
L
Linus Torvalds 已提交
2961

2962
	/* Cannot change chunk_size, layout, or level */
2963
	if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2964 2965
	    mddev->layout != mddev->new_layout ||
	    mddev->level != mddev->new_level) {
2966
		mddev->new_chunk_sectors = mddev->chunk_sectors;
2967 2968 2969 2970 2971
		mddev->new_layout = mddev->layout;
		mddev->new_level = mddev->level;
		return -EINVAL;
	}

2972 2973 2974
	err = md_allow_write(mddev);
	if (err)
		return err;
2975

2976 2977
	raid_disks = mddev->raid_disks + mddev->delta_disks;

2978 2979 2980 2981 2982 2983
	if (raid_disks < conf->raid_disks) {
		cnt=0;
		for (d= 0; d < conf->raid_disks; d++)
			if (conf->mirrors[d].rdev)
				cnt++;
		if (cnt > raid_disks)
L
Linus Torvalds 已提交
2984
			return -EBUSY;
2985
	}
L
Linus Torvalds 已提交
2986 2987 2988 2989 2990

	newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
	if (!newpoolinfo)
		return -ENOMEM;
	newpoolinfo->mddev = mddev;
2991
	newpoolinfo->raid_disks = raid_disks * 2;
L
Linus Torvalds 已提交
2992 2993 2994 2995 2996 2997 2998

	newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
				 r1bio_pool_free, newpoolinfo);
	if (!newpool) {
		kfree(newpoolinfo);
		return -ENOMEM;
	}
2999
	newmirrors = kzalloc(sizeof(struct raid1_info) * raid_disks * 2,
3000
			     GFP_KERNEL);
L
Linus Torvalds 已提交
3001 3002 3003 3004 3005 3006
	if (!newmirrors) {
		kfree(newpoolinfo);
		mempool_destroy(newpool);
		return -ENOMEM;
	}

3007
	raise_barrier(conf);
L
Linus Torvalds 已提交
3008 3009 3010 3011

	/* ok, everything is stopped */
	oldpool = conf->r1bio_pool;
	conf->r1bio_pool = newpool;
3012

3013
	for (d = d2 = 0; d < conf->raid_disks; d++) {
3014
		struct md_rdev *rdev = conf->mirrors[d].rdev;
3015
		if (rdev && rdev->raid_disk != d2) {
3016
			sysfs_unlink_rdev(mddev, rdev);
3017
			rdev->raid_disk = d2;
3018 3019
			sysfs_unlink_rdev(mddev, rdev);
			if (sysfs_link_rdev(mddev, rdev))
3020
				printk(KERN_WARNING
3021 3022
				       "md/raid1:%s: cannot register rd%d\n",
				       mdname(mddev), rdev->raid_disk);
3023
		}
3024 3025 3026
		if (rdev)
			newmirrors[d2++].rdev = rdev;
	}
L
Linus Torvalds 已提交
3027 3028 3029 3030 3031
	kfree(conf->mirrors);
	conf->mirrors = newmirrors;
	kfree(conf->poolinfo);
	conf->poolinfo = newpoolinfo;

3032
	spin_lock_irqsave(&conf->device_lock, flags);
L
Linus Torvalds 已提交
3033
	mddev->degraded += (raid_disks - conf->raid_disks);
3034
	spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
3035
	conf->raid_disks = mddev->raid_disks = raid_disks;
3036
	mddev->delta_disks = 0;
L
Linus Torvalds 已提交
3037

3038
	lower_barrier(conf);
L
Linus Torvalds 已提交
3039 3040 3041 3042 3043 3044 3045 3046

	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
	md_wakeup_thread(mddev->thread);

	mempool_destroy(oldpool);
	return 0;
}

3047
static void raid1_quiesce(struct mddev *mddev, int state)
3048
{
3049
	struct r1conf *conf = mddev->private;
3050 3051

	switch(state) {
3052 3053 3054
	case 2: /* wake for suspend */
		wake_up(&conf->wait_barrier);
		break;
3055
	case 1:
3056
		raise_barrier(conf);
3057
		break;
3058
	case 0:
3059
		lower_barrier(conf);
3060 3061 3062 3063
		break;
	}
}

3064
static void *raid1_takeover(struct mddev *mddev)
3065 3066 3067 3068 3069
{
	/* raid1 can take over:
	 *  raid5 with 2 devices, any layout or chunk size
	 */
	if (mddev->level == 5 && mddev->raid_disks == 2) {
3070
		struct r1conf *conf;
3071 3072 3073 3074 3075 3076 3077 3078 3079 3080
		mddev->new_level = 1;
		mddev->new_layout = 0;
		mddev->new_chunk_sectors = 0;
		conf = setup_conf(mddev);
		if (!IS_ERR(conf))
			conf->barrier = 1;
		return conf;
	}
	return ERR_PTR(-EINVAL);
}
L
Linus Torvalds 已提交
3081

3082
static struct md_personality raid1_personality =
L
Linus Torvalds 已提交
3083 3084
{
	.name		= "raid1",
3085
	.level		= 1,
L
Linus Torvalds 已提交
3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096
	.owner		= THIS_MODULE,
	.make_request	= make_request,
	.run		= run,
	.stop		= stop,
	.status		= status,
	.error_handler	= error,
	.hot_add_disk	= raid1_add_disk,
	.hot_remove_disk= raid1_remove_disk,
	.spare_active	= raid1_spare_active,
	.sync_request	= sync_request,
	.resize		= raid1_resize,
3097
	.size		= raid1_size,
3098
	.check_reshape	= raid1_reshape,
3099
	.quiesce	= raid1_quiesce,
3100
	.takeover	= raid1_takeover,
L
Linus Torvalds 已提交
3101 3102 3103 3104
};

static int __init raid_init(void)
{
3105
	return register_md_personality(&raid1_personality);
L
Linus Torvalds 已提交
3106 3107 3108 3109
}

static void raid_exit(void)
{
3110
	unregister_md_personality(&raid1_personality);
L
Linus Torvalds 已提交
3111 3112 3113 3114 3115
}

module_init(raid_init);
module_exit(raid_exit);
MODULE_LICENSE("GPL");
3116
MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
L
Linus Torvalds 已提交
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MODULE_ALIAS("md-personality-3"); /* RAID1 */
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MODULE_ALIAS("md-raid1");
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MODULE_ALIAS("md-level-1");
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module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);