raid1.c 73.9 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 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:
	while ( ++j < pi->raid_disks )
		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;

	for (i = 0; i < conf->raid_disks; i++) {
		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;

	for (i=0; i<conf->raid_disks; i++) {
		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;
	int raid_disks = r1_bio->mddev->raid_disks;

	for (mirror = 0; mirror < raid_disks; mirror++)
		if (r1_bio->bios[mirror] == bio)
			break;

	BUG_ON(mirror == raid_disks);
	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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	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);
	}

	rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
}

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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);
		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 start_disk;
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	int best_disk;
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	int i;
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	sector_t best_dist;
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	struct md_rdev *rdev;
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	int choose_first;
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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;
	best_dist = MaxSector;
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	best_good_sectors = 0;

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	if (conf->mddev->recovery_cp < MaxSector &&
	    (this_sector + sectors >= conf->next_resync)) {
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		choose_first = 1;
		start_disk = 0;
	} else {
		choose_first = 0;
		start_disk = conf->last_used;
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	}

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	for (i = 0 ; i < conf->raid_disks ; i++) {
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		sector_t dist;
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		sector_t first_bad;
		int bad_sectors;

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		int disk = start_disk + i;
		if (disk >= conf->raid_disks)
			disk -= conf->raid_disks;

		rdev = rcu_dereference(conf->mirrors[disk].rdev);
		if (r1_bio->bios[disk] == IO_BLOCKED
		    || rdev == NULL
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		    || test_bit(Faulty, &rdev->flags))
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			continue;
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		if (!test_bit(In_sync, &rdev->flags) &&
		    rdev->recovery_offset < this_sector + sectors)
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			continue;
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		if (test_bit(WriteMostly, &rdev->flags)) {
			/* Don't balance among write-mostly, just
			 * use the first as a last resort */
			if (best_disk < 0)
				best_disk = disk;
			continue;
		}
		/* This is a reasonable device to use.  It might
		 * even be best.
		 */
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		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;

N
NeilBrown 已提交
564 565 566 567 568 569 570 571
		dist = abs(this_sector - conf->mirrors[disk].head_position);
		if (choose_first
		    /* Don't change to another disk for sequential reads */
		    || conf->next_seq_sect == this_sector
		    || dist == 0
		    /* If device is idle, use it */
		    || atomic_read(&rdev->nr_pending) == 0) {
			best_disk = disk;
L
Linus Torvalds 已提交
572 573
			break;
		}
N
NeilBrown 已提交
574 575 576
		if (dist < best_dist) {
			best_dist = dist;
			best_disk = disk;
L
Linus Torvalds 已提交
577
		}
578
	}
L
Linus Torvalds 已提交
579

N
NeilBrown 已提交
580 581
	if (best_disk >= 0) {
		rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
582 583 584
		if (!rdev)
			goto retry;
		atomic_inc(&rdev->nr_pending);
N
NeilBrown 已提交
585
		if (test_bit(Faulty, &rdev->flags)) {
L
Linus Torvalds 已提交
586 587 588
			/* cannot risk returning a device that failed
			 * before we inc'ed nr_pending
			 */
589
			rdev_dec_pending(rdev, conf->mddev);
L
Linus Torvalds 已提交
590 591
			goto retry;
		}
592
		sectors = best_good_sectors;
593
		conf->next_seq_sect = this_sector + sectors;
N
NeilBrown 已提交
594
		conf->last_used = best_disk;
L
Linus Torvalds 已提交
595 596
	}
	rcu_read_unlock();
597
	*max_sectors = sectors;
L
Linus Torvalds 已提交
598

N
NeilBrown 已提交
599
	return best_disk;
L
Linus Torvalds 已提交
600 601
}

602
int md_raid1_congested(struct mddev *mddev, int bits)
603
{
604
	struct r1conf *conf = mddev->private;
605 606
	int i, ret = 0;

607 608 609 610
	if ((bits & (1 << BDI_async_congested)) &&
	    conf->pending_count >= max_queued_requests)
		return 1;

611 612
	rcu_read_lock();
	for (i = 0; i < mddev->raid_disks; i++) {
613
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
614
		if (rdev && !test_bit(Faulty, &rdev->flags)) {
615
			struct request_queue *q = bdev_get_queue(rdev->bdev);
616

617 618
			BUG_ON(!q);

619 620 621
			/* Note the '|| 1' - when read_balance prefers
			 * non-congested targets, it can be removed
			 */
622
			if ((bits & (1<<BDI_async_congested)) || 1)
623 624 625 626 627 628 629 630
				ret |= bdi_congested(&q->backing_dev_info, bits);
			else
				ret &= bdi_congested(&q->backing_dev_info, bits);
		}
	}
	rcu_read_unlock();
	return ret;
}
631
EXPORT_SYMBOL_GPL(md_raid1_congested);
632

633 634
static int raid1_congested(void *data, int bits)
{
635
	struct mddev *mddev = data;
636 637 638 639

	return mddev_congested(mddev, bits) ||
		md_raid1_congested(mddev, bits);
}
640

641
static void flush_pending_writes(struct r1conf *conf)
642 643 644 645 646 647 648 649 650
{
	/* 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);
651
		conf->pending_count = 0;
652 653 654 655
		spin_unlock_irq(&conf->device_lock);
		/* flush any pending bitmap writes to
		 * disk before proceeding w/ I/O */
		bitmap_unplug(conf->mddev->bitmap);
656
		wake_up(&conf->wait_barrier);
657 658 659 660 661 662 663 664 665

		while (bio) { /* submit pending writes */
			struct bio *next = bio->bi_next;
			bio->bi_next = NULL;
			generic_make_request(bio);
			bio = next;
		}
	} else
		spin_unlock_irq(&conf->device_lock);
J
Jens Axboe 已提交
666 667
}

668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687
/* 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
688 689 690
 */
#define RESYNC_DEPTH 32

691
static void raise_barrier(struct r1conf *conf)
L
Linus Torvalds 已提交
692 693
{
	spin_lock_irq(&conf->resync_lock);
694 695 696

	/* Wait until no block IO is waiting */
	wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
N
NeilBrown 已提交
697
			    conf->resync_lock, );
698 699 700 701

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

N
NeilBrown 已提交
702
	/* Now wait for all pending IO to complete */
703 704
	wait_event_lock_irq(conf->wait_barrier,
			    !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
N
NeilBrown 已提交
705
			    conf->resync_lock, );
706 707 708 709

	spin_unlock_irq(&conf->resync_lock);
}

710
static void lower_barrier(struct r1conf *conf)
711 712
{
	unsigned long flags;
713
	BUG_ON(conf->barrier <= 0);
714 715 716 717 718 719
	spin_lock_irqsave(&conf->resync_lock, flags);
	conf->barrier--;
	spin_unlock_irqrestore(&conf->resync_lock, flags);
	wake_up(&conf->wait_barrier);
}

720
static void wait_barrier(struct r1conf *conf)
721 722 723 724 725 726
{
	spin_lock_irq(&conf->resync_lock);
	if (conf->barrier) {
		conf->nr_waiting++;
		wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
				    conf->resync_lock,
N
NeilBrown 已提交
727
				    );
728
		conf->nr_waiting--;
L
Linus Torvalds 已提交
729
	}
730
	conf->nr_pending++;
L
Linus Torvalds 已提交
731 732 733
	spin_unlock_irq(&conf->resync_lock);
}

734
static void allow_barrier(struct r1conf *conf)
735 736 737 738 739 740 741 742
{
	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);
}

743
static void freeze_array(struct r1conf *conf)
744 745 746 747
{
	/* stop syncio and normal IO and wait for everything to
	 * go quite.
	 * We increment barrier and nr_waiting, and then
748 749 750 751 752 753 754 755
	 * 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.
756 757 758 759 760
	 */
	spin_lock_irq(&conf->resync_lock);
	conf->barrier++;
	conf->nr_waiting++;
	wait_event_lock_irq(conf->wait_barrier,
761
			    conf->nr_pending == conf->nr_queued+1,
762
			    conf->resync_lock,
N
NeilBrown 已提交
763
			    flush_pending_writes(conf));
764 765
	spin_unlock_irq(&conf->resync_lock);
}
766
static void unfreeze_array(struct r1conf *conf)
767 768 769 770 771 772 773 774 775
{
	/* 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);
}

776

777 778
/* duplicate the data pages for behind I/O 
 */
779
static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
780 781 782
{
	int i;
	struct bio_vec *bvec;
783
	struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
784
					GFP_NOIO);
785
	if (unlikely(!bvecs))
786
		return;
787 788

	bio_for_each_segment(bvec, bio, i) {
789 790 791
		bvecs[i] = *bvec;
		bvecs[i].bv_page = alloc_page(GFP_NOIO);
		if (unlikely(!bvecs[i].bv_page))
792
			goto do_sync_io;
793 794 795
		memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
		       kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
		kunmap(bvecs[i].bv_page);
796 797
		kunmap(bvec->bv_page);
	}
798
	r1_bio->behind_bvecs = bvecs;
799 800 801
	r1_bio->behind_page_count = bio->bi_vcnt;
	set_bit(R1BIO_BehindIO, &r1_bio->state);
	return;
802 803

do_sync_io:
804
	for (i = 0; i < bio->bi_vcnt; i++)
805 806 807
		if (bvecs[i].bv_page)
			put_page(bvecs[i].bv_page);
	kfree(bvecs);
808
	pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
809 810
}

811
static void make_request(struct mddev *mddev, struct bio * bio)
L
Linus Torvalds 已提交
812
{
813
	struct r1conf *conf = mddev->private;
814
	struct mirror_info *mirror;
815
	struct r1bio *r1_bio;
L
Linus Torvalds 已提交
816
	struct bio *read_bio;
817
	int i, disks;
818
	struct bitmap *bitmap;
819
	unsigned long flags;
820
	const int rw = bio_data_dir(bio);
821
	const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
T
Tejun Heo 已提交
822
	const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
823
	struct md_rdev *blocked_rdev;
N
NeilBrown 已提交
824
	int plugged;
825 826 827
	int first_clone;
	int sectors_handled;
	int max_sectors;
828

L
Linus Torvalds 已提交
829 830 831 832 833
	/*
	 * 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.
	 */
834

835 836
	md_write_start(mddev, bio); /* wait on superblock update early */

837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855
	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);
	}
856

857
	wait_barrier(conf);
L
Linus Torvalds 已提交
858

859 860
	bitmap = mddev->bitmap;

L
Linus Torvalds 已提交
861 862 863 864 865 866 867 868 869
	/*
	 * 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;
870
	r1_bio->state = 0;
L
Linus Torvalds 已提交
871 872 873
	r1_bio->mddev = mddev;
	r1_bio->sector = bio->bi_sector;

874 875 876 877 878 879 880 881 882 883
	/* 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);

884
	if (rw == READ) {
L
Linus Torvalds 已提交
885 886 887
		/*
		 * read balancing logic:
		 */
888 889 890 891
		int rdisk;

read_again:
		rdisk = read_balance(conf, r1_bio, &max_sectors);
L
Linus Torvalds 已提交
892 893 894 895

		if (rdisk < 0) {
			/* couldn't find anywhere to read from */
			raid_end_bio_io(r1_bio);
896
			return;
L
Linus Torvalds 已提交
897 898 899
		}
		mirror = conf->mirrors + rdisk;

900 901 902 903 904 905 906 907 908
		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
909 910
		r1_bio->read_disk = rdisk;

911
		read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
912 913
		md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
			    max_sectors);
L
Linus Torvalds 已提交
914 915 916 917 918 919

		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;
920
		read_bio->bi_rw = READ | do_sync;
L
Linus Torvalds 已提交
921 922
		read_bio->bi_private = r1_bio;

923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953
		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);
954
		return;
L
Linus Torvalds 已提交
955 956 957 958 959
	}

	/*
	 * WRITE:
	 */
960 961 962 963 964
	if (conf->pending_count >= max_queued_requests) {
		md_wakeup_thread(mddev->thread);
		wait_event(conf->wait_barrier,
			   conf->pending_count < max_queued_requests);
	}
965
	/* first select target devices under rcu_lock and
L
Linus Torvalds 已提交
966 967
	 * inc refcount on their rdev.  Record them by setting
	 * bios[x] to bio
968 969 970 971 972 973
	 * 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
974
	 */
N
NeilBrown 已提交
975 976
	plugged = mddev_check_plugged(mddev);

L
Linus Torvalds 已提交
977
	disks = conf->raid_disks;
978 979
 retry_write:
	blocked_rdev = NULL;
L
Linus Torvalds 已提交
980
	rcu_read_lock();
981
	max_sectors = r1_bio->sectors;
L
Linus Torvalds 已提交
982
	for (i = 0;  i < disks; i++) {
983
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
984 985 986 987 988
		if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
			atomic_inc(&rdev->nr_pending);
			blocked_rdev = rdev;
			break;
		}
989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018
		r1_bio->bios[i] = NULL;
		if (!rdev || test_bit(Faulty, &rdev->flags)) {
			set_bit(R1BIO_Degraded, &r1_bio->state);
			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;
1019
				rdev_dec_pending(rdev, mddev);
1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030
				/* 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;
1031
			}
1032 1033 1034 1035 1036 1037 1038
			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
1039 1040 1041
	}
	rcu_read_unlock();

1042 1043 1044 1045 1046 1047 1048
	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);
1049
		r1_bio->state = 0;
1050 1051 1052 1053 1054 1055
		allow_barrier(conf);
		md_wait_for_blocked_rdev(blocked_rdev, mddev);
		wait_barrier(conf);
		goto retry_write;
	}

1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066
	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);
1067
	}
1068
	sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
1069

1070
	atomic_set(&r1_bio->remaining, 1);
1071
	atomic_set(&r1_bio->behind_remaining, 0);
1072

1073
	first_clone = 1;
L
Linus Torvalds 已提交
1074 1075 1076 1077 1078
	for (i = 0; i < disks; i++) {
		struct bio *mbio;
		if (!r1_bio->bios[i])
			continue;

1079
		mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098
		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;
		}
1099
		if (r1_bio->behind_bvecs) {
1100 1101 1102 1103 1104 1105 1106
			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
1107
			 * know the original bi_idx, so we just free
1108 1109 1110
			 * them all
			 */
			__bio_for_each_segment(bvec, mbio, j, 0)
1111
				bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1112 1113 1114 1115
			if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
				atomic_inc(&r1_bio->behind_remaining);
		}

1116 1117 1118 1119 1120 1121 1122 1123 1124
		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;
		mbio->bi_rw = WRITE | do_flush_fua | do_sync;
		mbio->bi_private = r1_bio;

L
Linus Torvalds 已提交
1125
		atomic_inc(&r1_bio->remaining);
1126 1127
		spin_lock_irqsave(&conf->device_lock, flags);
		bio_list_add(&conf->pending_bio_list, mbio);
1128
		conf->pending_count++;
1129
		spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
1130
	}
1131 1132 1133
	/* Mustn't call r1_bio_write_done before this next test,
	 * as it could result in the bio being freed.
	 */
1134
	if (sectors_handled < (bio->bi_size >> 9)) {
1135
		r1_bio_write_done(r1_bio);
1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147
		/* 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;
	}

1148 1149 1150 1151 1152
	r1_bio_write_done(r1_bio);

	/* In case raid1d snuck in to freeze_array */
	wake_up(&conf->wait_barrier);

N
NeilBrown 已提交
1153
	if (do_sync || !bitmap || !plugged)
1154
		md_wakeup_thread(mddev->thread);
L
Linus Torvalds 已提交
1155 1156
}

1157
static void status(struct seq_file *seq, struct mddev *mddev)
L
Linus Torvalds 已提交
1158
{
1159
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1160 1161 1162
	int i;

	seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1163
		   conf->raid_disks - mddev->degraded);
1164 1165
	rcu_read_lock();
	for (i = 0; i < conf->raid_disks; i++) {
1166
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
L
Linus Torvalds 已提交
1167
		seq_printf(seq, "%s",
1168 1169 1170
			   rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
	}
	rcu_read_unlock();
L
Linus Torvalds 已提交
1171 1172 1173 1174
	seq_printf(seq, "]");
}


1175
static void error(struct mddev *mddev, struct md_rdev *rdev)
L
Linus Torvalds 已提交
1176 1177
{
	char b[BDEVNAME_SIZE];
1178
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1179 1180 1181 1182 1183 1184 1185

	/*
	 * 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
	 */
1186
	if (test_bit(In_sync, &rdev->flags)
1187
	    && (conf->raid_disks - mddev->degraded) == 1) {
L
Linus Torvalds 已提交
1188 1189
		/*
		 * Don't fail the drive, act as though we were just a
1190 1191 1192
		 * 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
1193
		 */
1194
		conf->recovery_disabled = mddev->recovery_disabled;
L
Linus Torvalds 已提交
1195
		return;
1196
	}
1197
	set_bit(Blocked, &rdev->flags);
1198 1199 1200
	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
1201
		mddev->degraded++;
1202
		set_bit(Faulty, &rdev->flags);
1203
		spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
1204 1205 1206
		/*
		 * if recovery is running, make sure it aborts.
		 */
1207
		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1208 1209
	} else
		set_bit(Faulty, &rdev->flags);
1210
	set_bit(MD_CHANGE_DEVS, &mddev->flags);
1211 1212 1213
	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
1214 1215
	       mdname(mddev), bdevname(rdev->bdev, b),
	       mdname(mddev), conf->raid_disks - mddev->degraded);
L
Linus Torvalds 已提交
1216 1217
}

1218
static void print_conf(struct r1conf *conf)
L
Linus Torvalds 已提交
1219 1220 1221
{
	int i;

N
NeilBrown 已提交
1222
	printk(KERN_DEBUG "RAID1 conf printout:\n");
L
Linus Torvalds 已提交
1223
	if (!conf) {
N
NeilBrown 已提交
1224
		printk(KERN_DEBUG "(!conf)\n");
L
Linus Torvalds 已提交
1225 1226
		return;
	}
N
NeilBrown 已提交
1227
	printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
L
Linus Torvalds 已提交
1228 1229
		conf->raid_disks);

1230
	rcu_read_lock();
L
Linus Torvalds 已提交
1231 1232
	for (i = 0; i < conf->raid_disks; i++) {
		char b[BDEVNAME_SIZE];
1233
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1234
		if (rdev)
N
NeilBrown 已提交
1235
			printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1236 1237 1238
			       i, !test_bit(In_sync, &rdev->flags),
			       !test_bit(Faulty, &rdev->flags),
			       bdevname(rdev->bdev,b));
L
Linus Torvalds 已提交
1239
	}
1240
	rcu_read_unlock();
L
Linus Torvalds 已提交
1241 1242
}

1243
static void close_sync(struct r1conf *conf)
L
Linus Torvalds 已提交
1244
{
1245 1246
	wait_barrier(conf);
	allow_barrier(conf);
L
Linus Torvalds 已提交
1247 1248 1249 1250 1251

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

1252
static int raid1_spare_active(struct mddev *mddev)
L
Linus Torvalds 已提交
1253 1254
{
	int i;
1255
	struct r1conf *conf = mddev->private;
1256 1257
	int count = 0;
	unsigned long flags;
L
Linus Torvalds 已提交
1258 1259 1260

	/*
	 * Find all failed disks within the RAID1 configuration 
1261 1262
	 * and mark them readable.
	 * Called under mddev lock, so rcu protection not needed.
L
Linus Torvalds 已提交
1263 1264
	 */
	for (i = 0; i < conf->raid_disks; i++) {
1265
		struct md_rdev *rdev = conf->mirrors[i].rdev;
1266 1267
		if (rdev
		    && !test_bit(Faulty, &rdev->flags)
1268
		    && !test_and_set_bit(In_sync, &rdev->flags)) {
1269
			count++;
1270
			sysfs_notify_dirent_safe(rdev->sysfs_state);
L
Linus Torvalds 已提交
1271 1272
		}
	}
1273 1274 1275
	spin_lock_irqsave(&conf->device_lock, flags);
	mddev->degraded -= count;
	spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
1276 1277

	print_conf(conf);
1278
	return count;
L
Linus Torvalds 已提交
1279 1280 1281
}


1282
static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
L
Linus Torvalds 已提交
1283
{
1284
	struct r1conf *conf = mddev->private;
1285
	int err = -EEXIST;
1286
	int mirror = 0;
1287
	struct mirror_info *p;
1288 1289
	int first = 0;
	int last = mddev->raid_disks - 1;
L
Linus Torvalds 已提交
1290

1291 1292 1293
	if (mddev->recovery_disabled == conf->recovery_disabled)
		return -EBUSY;

1294 1295 1296 1297
	if (rdev->raid_disk >= 0)
		first = last = rdev->raid_disk;

	for (mirror = first; mirror <= last; mirror++)
L
Linus Torvalds 已提交
1298 1299
		if ( !(p=conf->mirrors+mirror)->rdev) {

1300 1301
			disk_stack_limits(mddev->gendisk, rdev->bdev,
					  rdev->data_offset << 9);
1302 1303 1304 1305 1306
			/* as we don't honour merge_bvec_fn, we must
			 * never risk violating it, so limit
			 * ->max_segments to one lying with a single
			 * page, as a one page request is never in
			 * violation.
L
Linus Torvalds 已提交
1307
			 */
1308 1309 1310 1311 1312
			if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
				blk_queue_max_segments(mddev->queue, 1);
				blk_queue_segment_boundary(mddev->queue,
							   PAGE_CACHE_SIZE - 1);
			}
L
Linus Torvalds 已提交
1313 1314 1315

			p->head_position = 0;
			rdev->raid_disk = mirror;
1316
			err = 0;
1317 1318 1319 1320
			/* 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)
1321
				conf->fullsync = 1;
1322
			rcu_assign_pointer(p->rdev, rdev);
L
Linus Torvalds 已提交
1323 1324
			break;
		}
1325
	md_integrity_add_rdev(rdev, mddev);
L
Linus Torvalds 已提交
1326
	print_conf(conf);
1327
	return err;
L
Linus Torvalds 已提交
1328 1329
}

1330
static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
L
Linus Torvalds 已提交
1331
{
1332
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1333
	int err = 0;
1334
	int number = rdev->raid_disk;
1335
	struct mirror_info *p = conf->mirrors+ number;
L
Linus Torvalds 已提交
1336 1337

	print_conf(conf);
1338
	if (rdev == p->rdev) {
1339
		if (test_bit(In_sync, &rdev->flags) ||
L
Linus Torvalds 已提交
1340 1341 1342 1343
		    atomic_read(&rdev->nr_pending)) {
			err = -EBUSY;
			goto abort;
		}
N
NeilBrown 已提交
1344
		/* Only remove non-faulty devices if recovery
1345 1346 1347
		 * is not possible.
		 */
		if (!test_bit(Faulty, &rdev->flags) &&
1348
		    mddev->recovery_disabled != conf->recovery_disabled &&
1349 1350 1351 1352
		    mddev->degraded < conf->raid_disks) {
			err = -EBUSY;
			goto abort;
		}
L
Linus Torvalds 已提交
1353
		p->rdev = NULL;
1354
		synchronize_rcu();
L
Linus Torvalds 已提交
1355 1356 1357 1358
		if (atomic_read(&rdev->nr_pending)) {
			/* lost the race, try later */
			err = -EBUSY;
			p->rdev = rdev;
1359
			goto abort;
L
Linus Torvalds 已提交
1360
		}
1361
		err = md_integrity_register(mddev);
L
Linus Torvalds 已提交
1362 1363 1364 1365 1366 1367 1368 1369
	}
abort:

	print_conf(conf);
	return err;
}


1370
static void end_sync_read(struct bio *bio, int error)
L
Linus Torvalds 已提交
1371
{
1372
	struct r1bio *r1_bio = bio->bi_private;
L
Linus Torvalds 已提交
1373

1374
	update_head_pos(r1_bio->read_disk, r1_bio);
1375

L
Linus Torvalds 已提交
1376 1377 1378 1379 1380
	/*
	 * 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
	 */
1381
	if (test_bit(BIO_UPTODATE, &bio->bi_flags))
L
Linus Torvalds 已提交
1382
		set_bit(R1BIO_Uptodate, &r1_bio->state);
1383 1384 1385

	if (atomic_dec_and_test(&r1_bio->remaining))
		reschedule_retry(r1_bio);
L
Linus Torvalds 已提交
1386 1387
}

1388
static void end_sync_write(struct bio *bio, int error)
L
Linus Torvalds 已提交
1389 1390
{
	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1391
	struct r1bio *r1_bio = bio->bi_private;
1392
	struct mddev *mddev = r1_bio->mddev;
1393
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1394
	int mirror=0;
1395 1396
	sector_t first_bad;
	int bad_sectors;
L
Linus Torvalds 已提交
1397

1398 1399
	mirror = find_bio_disk(r1_bio, bio);

1400
	if (!uptodate) {
N
NeilBrown 已提交
1401
		sector_t sync_blocks = 0;
1402 1403 1404 1405
		sector_t s = r1_bio->sector;
		long sectors_to_go = r1_bio->sectors;
		/* make sure these bits doesn't get cleared. */
		do {
1406
			bitmap_end_sync(mddev->bitmap, s,
1407 1408 1409 1410
					&sync_blocks, 1);
			s += sync_blocks;
			sectors_to_go -= sync_blocks;
		} while (sectors_to_go > 0);
1411 1412 1413
		set_bit(WriteErrorSeen,
			&conf->mirrors[mirror].rdev->flags);
		set_bit(R1BIO_WriteError, &r1_bio->state);
1414 1415 1416
	} else if (is_badblock(conf->mirrors[mirror].rdev,
			       r1_bio->sector,
			       r1_bio->sectors,
1417 1418 1419 1420 1421 1422
			       &first_bad, &bad_sectors) &&
		   !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
				r1_bio->sector,
				r1_bio->sectors,
				&first_bad, &bad_sectors)
		)
1423
		set_bit(R1BIO_MadeGood, &r1_bio->state);
1424

L
Linus Torvalds 已提交
1425
	if (atomic_dec_and_test(&r1_bio->remaining)) {
1426
		int s = r1_bio->sectors;
1427 1428
		if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
		    test_bit(R1BIO_WriteError, &r1_bio->state))
1429 1430 1431 1432 1433
			reschedule_retry(r1_bio);
		else {
			put_buf(r1_bio);
			md_done_sync(mddev, s, uptodate);
		}
L
Linus Torvalds 已提交
1434 1435 1436
	}
}

1437
static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450
			    int sectors, struct page *page, int rw)
{
	if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
		/* success */
		return 1;
	if (rw == WRITE)
		set_bit(WriteErrorSeen, &rdev->flags);
	/* 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;
}

1451
static int fix_sync_read_error(struct r1bio *r1_bio)
L
Linus Torvalds 已提交
1452
{
1453 1454 1455 1456 1457 1458 1459
	/* 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.
1460 1461 1462
	 * 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.
1463
	 */
1464
	struct mddev *mddev = r1_bio->mddev;
1465
	struct r1conf *conf = mddev->private;
1466 1467 1468 1469 1470 1471 1472 1473 1474
	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;
1475
		struct md_rdev *rdev;
1476
		int start;
1477 1478 1479 1480 1481 1482 1483 1484 1485 1486

		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;
1487
				if (sync_page_io(rdev, sect, s<<9,
1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498
						 bio->bi_io_vec[idx].bv_page,
						 READ, false)) {
					success = 1;
					break;
				}
			}
			d++;
			if (d == conf->raid_disks)
				d = 0;
		} while (!success && d != r1_bio->read_disk);

1499
		if (!success) {
1500
			char b[BDEVNAME_SIZE];
1501 1502 1503 1504 1505 1506
			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.
			 */
1507 1508 1509 1510 1511
			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);
1512 1513 1514 1515 1516 1517 1518 1519
			for (d = 0; d < conf->raid_disks; d++) {
				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) {
1520 1521
				conf->recovery_disabled =
					mddev->recovery_disabled;
1522 1523 1524 1525 1526 1527 1528 1529 1530 1531
				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;
1532
		}
1533 1534 1535 1536 1537 1538 1539 1540 1541 1542

		start = d;
		/* write it back and re-read */
		while (d != r1_bio->read_disk) {
			if (d == 0)
				d = conf->raid_disks;
			d--;
			if (r1_bio->bios[d]->bi_end_io != end_sync_read)
				continue;
			rdev = conf->mirrors[d].rdev;
1543 1544 1545
			if (r1_sync_page_io(rdev, sect, s,
					    bio->bi_io_vec[idx].bv_page,
					    WRITE) == 0) {
1546 1547
				r1_bio->bios[d]->bi_end_io = NULL;
				rdev_dec_pending(rdev, mddev);
1548
			}
1549 1550 1551 1552 1553 1554 1555 1556 1557
		}
		d = start;
		while (d != r1_bio->read_disk) {
			if (d == 0)
				d = conf->raid_disks;
			d--;
			if (r1_bio->bios[d]->bi_end_io != end_sync_read)
				continue;
			rdev = conf->mirrors[d].rdev;
1558 1559 1560
			if (r1_sync_page_io(rdev, sect, s,
					    bio->bi_io_vec[idx].bv_page,
					    READ) != 0)
1561
				atomic_add(s, &rdev->corrected_errors);
1562
		}
1563 1564 1565 1566
		sectors -= s;
		sect += s;
		idx ++;
	}
1567
	set_bit(R1BIO_Uptodate, &r1_bio->state);
1568
	set_bit(BIO_UPTODATE, &bio->bi_flags);
1569 1570 1571
	return 1;
}

1572
static int process_checks(struct r1bio *r1_bio)
1573 1574 1575 1576 1577 1578 1579 1580
{
	/* 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
	 */
1581
	struct mddev *mddev = r1_bio->mddev;
1582
	struct r1conf *conf = mddev->private;
1583 1584 1585
	int primary;
	int i;

1586
	for (primary = 0; primary < conf->raid_disks; primary++)
1587 1588 1589 1590 1591 1592 1593
		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;
1594 1595 1596 1597 1598 1599
	for (i = 0; i < conf->raid_disks; i++) {
		int j;
		int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
		struct bio *pbio = r1_bio->bios[primary];
		struct bio *sbio = r1_bio->bios[i];
		int size;
1600

1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612
		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),
					   PAGE_SIZE))
					break;
1613
			}
1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648
		} else
			j = 0;
		if (j >= 0)
			mddev->resync_mismatches += r1_bio->sectors;
		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);
1649
		}
1650
	}
1651 1652 1653
	return 0;
}

1654
static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
1655
{
1656
	struct r1conf *conf = mddev->private;
1657 1658 1659 1660 1661 1662 1663 1664 1665 1666
	int i;
	int disks = conf->raid_disks;
	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;
1667 1668 1669 1670

	if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
		if (process_checks(r1_bio) < 0)
			return;
1671 1672 1673
	/*
	 * schedule writes
	 */
L
Linus Torvalds 已提交
1674 1675 1676
	atomic_set(&r1_bio->remaining, 1);
	for (i = 0; i < disks ; i++) {
		wbio = r1_bio->bios[i];
1677 1678 1679 1680
		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
1681 1682
			continue;

1683 1684
		wbio->bi_rw = WRITE;
		wbio->bi_end_io = end_sync_write;
L
Linus Torvalds 已提交
1685 1686
		atomic_inc(&r1_bio->remaining);
		md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1687

L
Linus Torvalds 已提交
1688 1689 1690 1691
		generic_make_request(wbio);
	}

	if (atomic_dec_and_test(&r1_bio->remaining)) {
1692
		/* if we're here, all write(s) have completed, so clean up */
L
Linus Torvalds 已提交
1693 1694 1695 1696 1697 1698 1699 1700 1701 1702
		md_done_sync(mddev, r1_bio->sectors, 1);
		put_buf(r1_bio);
	}
}

/*
 * This is a kernel thread which:
 *
 *	1.	Retries failed read operations on working mirrors.
 *	2.	Updates the raid superblock when problems encounter.
1703
 *	3.	Performs writes following reads for array synchronising.
L
Linus Torvalds 已提交
1704 1705
 */

1706
static void fix_read_error(struct r1conf *conf, int read_disk,
1707 1708
			   sector_t sect, int sectors)
{
1709
	struct mddev *mddev = conf->mddev;
1710 1711 1712 1713 1714
	while(sectors) {
		int s = sectors;
		int d = read_disk;
		int success = 0;
		int start;
1715
		struct md_rdev *rdev;
1716 1717 1718 1719 1720 1721 1722 1723 1724 1725

		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....
			 */
1726 1727 1728
			sector_t first_bad;
			int bad_sectors;

1729 1730 1731
			rdev = conf->mirrors[d].rdev;
			if (rdev &&
			    test_bit(In_sync, &rdev->flags) &&
1732 1733
			    is_badblock(rdev, sect, s,
					&first_bad, &bad_sectors) == 0 &&
J
Jonathan Brassow 已提交
1734 1735
			    sync_page_io(rdev, sect, s<<9,
					 conf->tmppage, READ, false))
1736 1737 1738 1739 1740 1741 1742 1743 1744
				success = 1;
			else {
				d++;
				if (d == conf->raid_disks)
					d = 0;
			}
		} while (!success && d != read_disk);

		if (!success) {
1745
			/* Cannot read from anywhere - mark it bad */
1746
			struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
1747 1748
			if (!rdev_set_badblocks(rdev, sect, s, 0))
				md_error(mddev, rdev);
1749 1750 1751 1752 1753 1754 1755 1756 1757 1758
			break;
		}
		/* write it back and re-read */
		start = d;
		while (d != read_disk) {
			if (d==0)
				d = conf->raid_disks;
			d--;
			rdev = conf->mirrors[d].rdev;
			if (rdev &&
1759 1760 1761
			    test_bit(In_sync, &rdev->flags))
				r1_sync_page_io(rdev, sect, s,
						conf->tmppage, WRITE);
1762 1763 1764 1765 1766 1767 1768 1769 1770 1771
		}
		d = start;
		while (d != read_disk) {
			char b[BDEVNAME_SIZE];
			if (d==0)
				d = conf->raid_disks;
			d--;
			rdev = conf->mirrors[d].rdev;
			if (rdev &&
			    test_bit(In_sync, &rdev->flags)) {
1772 1773
				if (r1_sync_page_io(rdev, sect, s,
						    conf->tmppage, READ)) {
1774 1775
					atomic_add(s, &rdev->corrected_errors);
					printk(KERN_INFO
N
NeilBrown 已提交
1776
					       "md/raid1:%s: read error corrected "
1777 1778
					       "(%d sectors at %llu on %s)\n",
					       mdname(mddev), s,
1779 1780
					       (unsigned long long)(sect +
					           rdev->data_offset),
1781 1782 1783 1784 1785 1786 1787 1788 1789
					       bdevname(rdev->bdev, b));
				}
			}
		}
		sectors -= s;
		sect += s;
	}
}

1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808
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);
}

1809
static int narrow_write_error(struct r1bio *r1_bio, int i)
1810
{
1811
	struct mddev *mddev = r1_bio->mddev;
1812
	struct r1conf *conf = mddev->private;
1813
	struct md_rdev *rdev = conf->mirrors[i].rdev;
1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884
	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;
}

1885
static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
1886 1887 1888 1889
{
	int m;
	int s = r1_bio->sectors;
	for (m = 0; m < conf->raid_disks ; m++) {
1890
		struct md_rdev *rdev = conf->mirrors[m].rdev;
1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907
		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)) {
			rdev_clear_badblocks(rdev, r1_bio->sector, s);
		}
		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);
}

1908
static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
1909 1910 1911 1912
{
	int m;
	for (m = 0; m < conf->raid_disks ; m++)
		if (r1_bio->bios[m] == IO_MADE_GOOD) {
1913
			struct md_rdev *rdev = conf->mirrors[m].rdev;
1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936
			rdev_clear_badblocks(rdev,
					     r1_bio->sector,
					     r1_bio->sectors);
			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);
}

1937
static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
1938 1939 1940
{
	int disk;
	int max_sectors;
1941
	struct mddev *mddev = conf->mddev;
1942 1943
	struct bio *bio;
	char b[BDEVNAME_SIZE];
1944
	struct md_rdev *rdev;
1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026

	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);

	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);
	}
}

2027
static void raid1d(struct mddev *mddev)
L
Linus Torvalds 已提交
2028
{
2029
	struct r1bio *r1_bio;
L
Linus Torvalds 已提交
2030
	unsigned long flags;
2031
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
2032
	struct list_head *head = &conf->retry_list;
2033
	struct blk_plug plug;
L
Linus Torvalds 已提交
2034 2035

	md_check_recovery(mddev);
2036 2037

	blk_start_plug(&plug);
L
Linus Torvalds 已提交
2038
	for (;;) {
2039

N
NeilBrown 已提交
2040 2041
		if (atomic_read(&mddev->plug_cnt) == 0)
			flush_pending_writes(conf);
2042

2043 2044 2045
		spin_lock_irqsave(&conf->device_lock, flags);
		if (list_empty(head)) {
			spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
2046
			break;
2047
		}
2048
		r1_bio = list_entry(head->prev, struct r1bio, retry_list);
L
Linus Torvalds 已提交
2049
		list_del(head->prev);
2050
		conf->nr_queued--;
L
Linus Torvalds 已提交
2051 2052 2053
		spin_unlock_irqrestore(&conf->device_lock, flags);

		mddev = r1_bio->mddev;
2054
		conf = mddev->private;
2055
		if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2056
			if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2057 2058 2059
			    test_bit(R1BIO_WriteError, &r1_bio->state))
				handle_sync_write_finished(conf, r1_bio);
			else
2060
				sync_request_write(mddev, r1_bio);
2061
		} else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2062 2063 2064 2065 2066
			   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
2067 2068 2069 2070
			/* just a partial read to be scheduled from separate
			 * context
			 */
			generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2071

N
NeilBrown 已提交
2072
		cond_resched();
2073 2074
		if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
			md_check_recovery(mddev);
L
Linus Torvalds 已提交
2075
	}
2076
	blk_finish_plug(&plug);
L
Linus Torvalds 已提交
2077 2078 2079
}


2080
static int init_resync(struct r1conf *conf)
L
Linus Torvalds 已提交
2081 2082 2083 2084
{
	int buffs;

	buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2085
	BUG_ON(conf->r1buf_pool);
L
Linus Torvalds 已提交
2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103
	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.
 */

2104
static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
L
Linus Torvalds 已提交
2105
{
2106
	struct r1conf *conf = mddev->private;
2107
	struct r1bio *r1_bio;
L
Linus Torvalds 已提交
2108 2109
	struct bio *bio;
	sector_t max_sector, nr_sectors;
2110
	int disk = -1;
L
Linus Torvalds 已提交
2111
	int i;
2112 2113
	int wonly = -1;
	int write_targets = 0, read_targets = 0;
N
NeilBrown 已提交
2114
	sector_t sync_blocks;
2115
	int still_degraded = 0;
2116 2117
	int good_sectors = RESYNC_SECTORS;
	int min_bad = 0; /* number of sectors that are bad in all devices */
L
Linus Torvalds 已提交
2118 2119 2120

	if (!conf->r1buf_pool)
		if (init_resync(conf))
2121
			return 0;
L
Linus Torvalds 已提交
2122

A
Andre Noll 已提交
2123
	max_sector = mddev->dev_sectors;
L
Linus Torvalds 已提交
2124
	if (sector_nr >= max_sector) {
2125 2126 2127 2128 2129
		/* 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
		 */
2130 2131
		if (mddev->curr_resync < max_sector) /* aborted */
			bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2132
						&sync_blocks, 1);
2133
		else /* completed sync */
2134
			conf->fullsync = 0;
2135 2136

		bitmap_close_sync(mddev->bitmap);
L
Linus Torvalds 已提交
2137 2138 2139 2140
		close_sync(conf);
		return 0;
	}

2141 2142
	if (mddev->bitmap == NULL &&
	    mddev->recovery_cp == MaxSector &&
2143
	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2144 2145 2146 2147
	    conf->fullsync == 0) {
		*skipped = 1;
		return max_sector - sector_nr;
	}
2148 2149 2150
	/* before building a request, check if we can skip these blocks..
	 * This call the bitmap_start_sync doesn't actually record anything
	 */
2151
	if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2152
	    !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2153 2154 2155 2156
		/* We can skip this block, and probably several more */
		*skipped = 1;
		return sync_blocks;
	}
L
Linus Torvalds 已提交
2157
	/*
2158 2159 2160
	 * 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
2161
	 */
2162
	if (!go_faster && conf->nr_waiting)
L
Linus Torvalds 已提交
2163
		msleep_interruptible(1000);
2164

N
NeilBrown 已提交
2165
	bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2166
	r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2167 2168 2169
	raise_barrier(conf);

	conf->next_resync = sector_nr;
L
Linus Torvalds 已提交
2170

2171
	rcu_read_lock();
L
Linus Torvalds 已提交
2172
	/*
2173 2174 2175 2176 2177 2178
	 * 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
2179 2180 2181 2182
	 */

	r1_bio->mddev = mddev;
	r1_bio->sector = sector_nr;
2183
	r1_bio->state = 0;
L
Linus Torvalds 已提交
2184 2185 2186
	set_bit(R1BIO_IsSync, &r1_bio->state);

	for (i=0; i < conf->raid_disks; i++) {
2187
		struct md_rdev *rdev;
L
Linus Torvalds 已提交
2188 2189 2190 2191
		bio = r1_bio->bios[i];

		/* take from bio_init */
		bio->bi_next = NULL;
2192
		bio->bi_flags &= ~(BIO_POOL_MASK-1);
L
Linus Torvalds 已提交
2193
		bio->bi_flags |= 1 << BIO_UPTODATE;
2194
		bio->bi_rw = READ;
L
Linus Torvalds 已提交
2195 2196 2197 2198 2199 2200 2201
		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;

2202 2203
		rdev = rcu_dereference(conf->mirrors[i].rdev);
		if (rdev == NULL ||
2204
		    test_bit(Faulty, &rdev->flags)) {
2205
			still_degraded = 1;
2206
		} else if (!test_bit(In_sync, &rdev->flags)) {
L
Linus Torvalds 已提交
2207 2208 2209
			bio->bi_rw = WRITE;
			bio->bi_end_io = end_sync_write;
			write_targets ++;
2210 2211
		} else {
			/* may need to read from here */
2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236
			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++;
2237 2238
			}
		}
2239 2240 2241 2242 2243 2244
		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
2245
	}
2246 2247 2248 2249
	rcu_read_unlock();
	if (disk < 0)
		disk = wonly;
	r1_bio->read_disk = disk;
2250

2251 2252 2253 2254 2255 2256 2257
	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;
		for (i = 0 ; i < conf->raid_disks ; i++)
			if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2258
				struct md_rdev *rdev =
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
					rcu_dereference(conf->mirrors[i].rdev);
				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;
	}

2287 2288 2289 2290 2291
	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
2292 2293 2294
		/* There is nowhere to write, so all non-sync
		 * drives must be failed - so we are finished
		 */
2295 2296
		sector_t rv = max_sector - sector_nr;
		*skipped = 1;
L
Linus Torvalds 已提交
2297 2298 2299 2300
		put_buf(r1_bio);
		return rv;
	}

2301 2302
	if (max_sector > mddev->resync_max)
		max_sector = mddev->resync_max; /* Don't do IO beyond here */
2303 2304
	if (max_sector > sector_nr + good_sectors)
		max_sector = sector_nr + good_sectors;
L
Linus Torvalds 已提交
2305
	nr_sectors = 0;
2306
	sync_blocks = 0;
L
Linus Torvalds 已提交
2307 2308 2309 2310 2311 2312 2313
	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;
2314 2315
		if (sync_blocks == 0) {
			if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2316 2317 2318
					       &sync_blocks, still_degraded) &&
			    !conf->fullsync &&
			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2319
				break;
2320
			BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2321
			if ((len >> 9) > sync_blocks)
2322
				len = sync_blocks<<9;
2323
		}
2324

L
Linus Torvalds 已提交
2325 2326 2327
		for (i=0 ; i < conf->raid_disks; i++) {
			bio = r1_bio->bios[i];
			if (bio->bi_end_io) {
2328
				page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
L
Linus Torvalds 已提交
2329 2330
				if (bio_add_page(bio, page, len, 0) == 0) {
					/* stop here */
2331
					bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
L
Linus Torvalds 已提交
2332 2333 2334
					while (i > 0) {
						i--;
						bio = r1_bio->bios[i];
2335 2336
						if (bio->bi_end_io==NULL)
							continue;
L
Linus Torvalds 已提交
2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347
						/* 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;
2348
		sync_blocks -= (len>>9);
L
Linus Torvalds 已提交
2349 2350 2351 2352
	} while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
 bio_full:
	r1_bio->sectors = nr_sectors;

2353 2354 2355 2356 2357 2358 2359 2360
	/* 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);
		for (i=0; i<conf->raid_disks; i++) {
			bio = r1_bio->bios[i];
			if (bio->bi_end_io == end_sync_read) {
2361
				md_sync_acct(bio->bi_bdev, nr_sectors);
2362 2363 2364 2365 2366 2367
				generic_make_request(bio);
			}
		}
	} else {
		atomic_set(&r1_bio->remaining, 1);
		bio = r1_bio->bios[r1_bio->read_disk];
2368
		md_sync_acct(bio->bi_bdev, nr_sectors);
2369
		generic_make_request(bio);
L
Linus Torvalds 已提交
2370

2371
	}
L
Linus Torvalds 已提交
2372 2373 2374
	return nr_sectors;
}

2375
static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2376 2377 2378 2379 2380 2381 2382
{
	if (sectors)
		return sectors;

	return mddev->dev_sectors;
}

2383
static struct r1conf *setup_conf(struct mddev *mddev)
L
Linus Torvalds 已提交
2384
{
2385
	struct r1conf *conf;
2386
	int i;
2387
	struct mirror_info *disk;
2388
	struct md_rdev *rdev;
2389
	int err = -ENOMEM;
L
Linus Torvalds 已提交
2390

2391
	conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
L
Linus Torvalds 已提交
2392
	if (!conf)
2393
		goto abort;
L
Linus Torvalds 已提交
2394

2395
	conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
L
Linus Torvalds 已提交
2396 2397
				 GFP_KERNEL);
	if (!conf->mirrors)
2398
		goto abort;
L
Linus Torvalds 已提交
2399

2400 2401
	conf->tmppage = alloc_page(GFP_KERNEL);
	if (!conf->tmppage)
2402
		goto abort;
2403

2404
	conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
L
Linus Torvalds 已提交
2405
	if (!conf->poolinfo)
2406
		goto abort;
L
Linus Torvalds 已提交
2407 2408 2409 2410 2411
	conf->poolinfo->raid_disks = mddev->raid_disks;
	conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
					  r1bio_pool_free,
					  conf->poolinfo);
	if (!conf->r1bio_pool)
2412 2413
		goto abort;

2414
	conf->poolinfo->mddev = mddev;
L
Linus Torvalds 已提交
2415

2416
	spin_lock_init(&conf->device_lock);
2417
	list_for_each_entry(rdev, &mddev->disks, same_set) {
2418
		int disk_idx = rdev->raid_disk;
L
Linus Torvalds 已提交
2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432
		if (disk_idx >= mddev->raid_disks
		    || disk_idx < 0)
			continue;
		disk = conf->mirrors + disk_idx;

		disk->rdev = rdev;

		disk->head_position = 0;
	}
	conf->raid_disks = mddev->raid_disks;
	conf->mddev = mddev;
	INIT_LIST_HEAD(&conf->retry_list);

	spin_lock_init(&conf->resync_lock);
2433
	init_waitqueue_head(&conf->wait_barrier);
L
Linus Torvalds 已提交
2434

2435
	bio_list_init(&conf->pending_bio_list);
2436
	conf->pending_count = 0;
2437
	conf->recovery_disabled = mddev->recovery_disabled - 1;
2438

2439
	conf->last_used = -1;
L
Linus Torvalds 已提交
2440 2441 2442 2443
	for (i = 0; i < conf->raid_disks; i++) {

		disk = conf->mirrors + i;

2444 2445
		if (!disk->rdev ||
		    !test_bit(In_sync, &disk->rdev->flags)) {
L
Linus Torvalds 已提交
2446
			disk->head_position = 0;
2447 2448
			if (disk->rdev)
				conf->fullsync = 1;
2449 2450 2451 2452 2453 2454
		} else if (conf->last_used < 0)
			/*
			 * The first working device is used as a
			 * starting point to read balancing.
			 */
			conf->last_used = i;
L
Linus Torvalds 已提交
2455
	}
2456 2457 2458

	err = -EIO;
	if (conf->last_used < 0) {
N
NeilBrown 已提交
2459
		printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
2460 2461 2462 2463 2464 2465 2466
		       mdname(mddev));
		goto abort;
	}
	err = -ENOMEM;
	conf->thread = md_register_thread(raid1d, mddev, NULL);
	if (!conf->thread) {
		printk(KERN_ERR
N
NeilBrown 已提交
2467
		       "md/raid1:%s: couldn't allocate thread\n",
2468 2469
		       mdname(mddev));
		goto abort;
2470
	}
L
Linus Torvalds 已提交
2471

2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485
	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);
}

2486
static int run(struct mddev *mddev)
2487
{
2488
	struct r1conf *conf;
2489
	int i;
2490
	struct md_rdev *rdev;
2491 2492

	if (mddev->level != 1) {
N
NeilBrown 已提交
2493
		printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2494 2495 2496 2497
		       mdname(mddev), mddev->level);
		return -EIO;
	}
	if (mddev->reshape_position != MaxSector) {
N
NeilBrown 已提交
2498
		printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2499 2500 2501
		       mdname(mddev));
		return -EIO;
	}
L
Linus Torvalds 已提交
2502
	/*
2503 2504 2505
	 * 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
2506
	 */
2507 2508 2509 2510
	if (mddev->private == NULL)
		conf = setup_conf(mddev);
	else
		conf = mddev->private;
L
Linus Torvalds 已提交
2511

2512 2513
	if (IS_ERR(conf))
		return PTR_ERR(conf);
L
Linus Torvalds 已提交
2514

2515
	list_for_each_entry(rdev, &mddev->disks, same_set) {
2516 2517
		if (!mddev->gendisk)
			continue;
2518 2519 2520
		disk_stack_limits(mddev->gendisk, rdev->bdev,
				  rdev->data_offset << 9);
		/* as we don't honour merge_bvec_fn, we must never risk
2521 2522
		 * violating it, so limit ->max_segments to 1 lying within
		 * a single page, as a one page request is never in violation.
2523
		 */
2524 2525 2526 2527 2528
		if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
			blk_queue_max_segments(mddev->queue, 1);
			blk_queue_segment_boundary(mddev->queue,
						   PAGE_CACHE_SIZE - 1);
		}
L
Linus Torvalds 已提交
2529
	}
2530

2531 2532 2533 2534 2535 2536 2537 2538 2539 2540
	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;

2541
	if (mddev->recovery_cp != MaxSector)
N
NeilBrown 已提交
2542
		printk(KERN_NOTICE "md/raid1:%s: not clean"
2543 2544
		       " -- starting background reconstruction\n",
		       mdname(mddev));
L
Linus Torvalds 已提交
2545
	printk(KERN_INFO 
N
NeilBrown 已提交
2546
		"md/raid1:%s: active with %d out of %d mirrors\n",
L
Linus Torvalds 已提交
2547 2548
		mdname(mddev), mddev->raid_disks - mddev->degraded, 
		mddev->raid_disks);
2549

L
Linus Torvalds 已提交
2550 2551 2552
	/*
	 * Ok, everything is just fine now
	 */
2553 2554 2555 2556
	mddev->thread = conf->thread;
	conf->thread = NULL;
	mddev->private = conf;

2557
	md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
L
Linus Torvalds 已提交
2558

2559 2560 2561 2562
	if (mddev->queue) {
		mddev->queue->backing_dev_info.congested_fn = raid1_congested;
		mddev->queue->backing_dev_info.congested_data = mddev;
	}
2563
	return md_integrity_register(mddev);
L
Linus Torvalds 已提交
2564 2565
}

2566
static int stop(struct mddev *mddev)
L
Linus Torvalds 已提交
2567
{
2568
	struct r1conf *conf = mddev->private;
2569 2570 2571
	struct bitmap *bitmap = mddev->bitmap;

	/* wait for behind writes to complete */
2572
	if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
N
NeilBrown 已提交
2573 2574
		printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
		       mdname(mddev));
2575
		/* need to kick something here to make sure I/O goes? */
2576 2577
		wait_event(bitmap->behind_wait,
			   atomic_read(&bitmap->behind_writes) == 0);
2578
	}
L
Linus Torvalds 已提交
2579

2580 2581 2582
	raise_barrier(conf);
	lower_barrier(conf);

2583
	md_unregister_thread(&mddev->thread);
L
Linus Torvalds 已提交
2584 2585
	if (conf->r1bio_pool)
		mempool_destroy(conf->r1bio_pool);
2586 2587
	kfree(conf->mirrors);
	kfree(conf->poolinfo);
L
Linus Torvalds 已提交
2588 2589 2590 2591 2592
	kfree(conf);
	mddev->private = NULL;
	return 0;
}

2593
static int raid1_resize(struct mddev *mddev, sector_t sectors)
L
Linus Torvalds 已提交
2594 2595 2596 2597 2598 2599 2600 2601
{
	/* 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.
	 */
2602
	md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
D
Dan Williams 已提交
2603 2604
	if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
		return -EINVAL;
2605
	set_capacity(mddev->gendisk, mddev->array_sectors);
2606
	revalidate_disk(mddev->gendisk);
D
Dan Williams 已提交
2607
	if (sectors > mddev->dev_sectors &&
2608
	    mddev->recovery_cp > mddev->dev_sectors) {
A
Andre Noll 已提交
2609
		mddev->recovery_cp = mddev->dev_sectors;
L
Linus Torvalds 已提交
2610 2611
		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
	}
D
Dan Williams 已提交
2612
	mddev->dev_sectors = sectors;
2613
	mddev->resync_max_sectors = sectors;
L
Linus Torvalds 已提交
2614 2615 2616
	return 0;
}

2617
static int raid1_reshape(struct mddev *mddev)
L
Linus Torvalds 已提交
2618 2619 2620 2621 2622 2623 2624 2625
{
	/* 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.
2626 2627 2628
	 *
	 * At the same time, we "pack" the devices so that all the missing
	 * devices have the higher raid_disk numbers.
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Linus Torvalds 已提交
2629 2630 2631
	 */
	mempool_t *newpool, *oldpool;
	struct pool_info *newpoolinfo;
2632
	struct mirror_info *newmirrors;
2633
	struct r1conf *conf = mddev->private;
2634
	int cnt, raid_disks;
2635
	unsigned long flags;
2636
	int d, d2, err;
L
Linus Torvalds 已提交
2637

2638
	/* Cannot change chunk_size, layout, or level */
2639
	if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2640 2641
	    mddev->layout != mddev->new_layout ||
	    mddev->level != mddev->new_level) {
2642
		mddev->new_chunk_sectors = mddev->chunk_sectors;
2643 2644 2645 2646 2647
		mddev->new_layout = mddev->layout;
		mddev->new_level = mddev->level;
		return -EINVAL;
	}

2648 2649 2650
	err = md_allow_write(mddev);
	if (err)
		return err;
2651

2652 2653
	raid_disks = mddev->raid_disks + mddev->delta_disks;

2654 2655 2656 2657 2658 2659
	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
2660
			return -EBUSY;
2661
	}
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Linus Torvalds 已提交
2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674

	newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
	if (!newpoolinfo)
		return -ENOMEM;
	newpoolinfo->mddev = mddev;
	newpoolinfo->raid_disks = raid_disks;

	newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
				 r1bio_pool_free, newpoolinfo);
	if (!newpool) {
		kfree(newpoolinfo);
		return -ENOMEM;
	}
2675
	newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
L
Linus Torvalds 已提交
2676 2677 2678 2679 2680 2681
	if (!newmirrors) {
		kfree(newpoolinfo);
		mempool_destroy(newpool);
		return -ENOMEM;
	}

2682
	raise_barrier(conf);
L
Linus Torvalds 已提交
2683 2684 2685 2686

	/* ok, everything is stopped */
	oldpool = conf->r1bio_pool;
	conf->r1bio_pool = newpool;
2687

2688
	for (d = d2 = 0; d < conf->raid_disks; d++) {
2689
		struct md_rdev *rdev = conf->mirrors[d].rdev;
2690
		if (rdev && rdev->raid_disk != d2) {
2691
			sysfs_unlink_rdev(mddev, rdev);
2692
			rdev->raid_disk = d2;
2693 2694
			sysfs_unlink_rdev(mddev, rdev);
			if (sysfs_link_rdev(mddev, rdev))
2695
				printk(KERN_WARNING
2696 2697
				       "md/raid1:%s: cannot register rd%d\n",
				       mdname(mddev), rdev->raid_disk);
2698
		}
2699 2700 2701
		if (rdev)
			newmirrors[d2++].rdev = rdev;
	}
L
Linus Torvalds 已提交
2702 2703 2704 2705 2706
	kfree(conf->mirrors);
	conf->mirrors = newmirrors;
	kfree(conf->poolinfo);
	conf->poolinfo = newpoolinfo;

2707
	spin_lock_irqsave(&conf->device_lock, flags);
L
Linus Torvalds 已提交
2708
	mddev->degraded += (raid_disks - conf->raid_disks);
2709
	spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
2710
	conf->raid_disks = mddev->raid_disks = raid_disks;
2711
	mddev->delta_disks = 0;
L
Linus Torvalds 已提交
2712

2713
	conf->last_used = 0; /* just make sure it is in-range */
2714
	lower_barrier(conf);
L
Linus Torvalds 已提交
2715 2716 2717 2718 2719 2720 2721 2722

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

	mempool_destroy(oldpool);
	return 0;
}

2723
static void raid1_quiesce(struct mddev *mddev, int state)
2724
{
2725
	struct r1conf *conf = mddev->private;
2726 2727

	switch(state) {
2728 2729 2730
	case 2: /* wake for suspend */
		wake_up(&conf->wait_barrier);
		break;
2731
	case 1:
2732
		raise_barrier(conf);
2733
		break;
2734
	case 0:
2735
		lower_barrier(conf);
2736 2737 2738 2739
		break;
	}
}

2740
static void *raid1_takeover(struct mddev *mddev)
2741 2742 2743 2744 2745
{
	/* raid1 can take over:
	 *  raid5 with 2 devices, any layout or chunk size
	 */
	if (mddev->level == 5 && mddev->raid_disks == 2) {
2746
		struct r1conf *conf;
2747 2748 2749 2750 2751 2752 2753 2754 2755 2756
		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
2757

2758
static struct md_personality raid1_personality =
L
Linus Torvalds 已提交
2759 2760
{
	.name		= "raid1",
2761
	.level		= 1,
L
Linus Torvalds 已提交
2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772
	.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,
2773
	.size		= raid1_size,
2774
	.check_reshape	= raid1_reshape,
2775
	.quiesce	= raid1_quiesce,
2776
	.takeover	= raid1_takeover,
L
Linus Torvalds 已提交
2777 2778 2779 2780
};

static int __init raid_init(void)
{
2781
	return register_md_personality(&raid1_personality);
L
Linus Torvalds 已提交
2782 2783 2784 2785
}

static void raid_exit(void)
{
2786
	unregister_md_personality(&raid1_personality);
L
Linus Torvalds 已提交
2787 2788 2789 2790 2791
}

module_init(raid_init);
module_exit(raid_exit);
MODULE_LICENSE("GPL");
2792
MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
L
Linus Torvalds 已提交
2793
MODULE_ALIAS("md-personality-3"); /* RAID1 */
2794
MODULE_ALIAS("md-raid1");
2795
MODULE_ALIAS("md-level-1");
2796 2797

module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);