raid1.c 86.4 KB
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/*
 * raid1.c : Multiple Devices driver for Linux
 *
 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
 *
 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
 *
 * RAID-1 management functions.
 *
 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
 *
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 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
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 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
 *
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 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
 * bitmapped intelligence in resync:
 *
 *      - bitmap marked during normal i/o
 *      - bitmap used to skip nondirty blocks during sync
 *
 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
 * - persistent bitmap code
 *
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 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * You should have received a copy of the GNU General Public License
 * (for example /usr/src/linux/COPYING); if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

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

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

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

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/* When there are this many requests queue to be written by
 * the raid1 thread, we become 'congested' to provide back-pressure
 * for writeback.
 */
static int max_queued_requests = 1024;
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static void allow_barrier(struct r1conf *conf, sector_t start_next_window,
			  sector_t bi_sector);
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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)
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#define RESYNC_DEPTH 32
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#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
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#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
#define NEXT_NORMALIO_DISTANCE (3 * RESYNC_WINDOW_SECTORS)
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static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
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{
	struct pool_info *pi = data;
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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];
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		bio->bi_vcnt = RESYNC_PAGES;
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		if (bio_alloc_pages(bio, gfp_flags))
			goto out_free_bio;
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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_bio:
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	while (++j < pi->raid_disks)
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		bio_put(r1_bio->bios[j]);
	r1bio_pool_free(r1_bio, data);
	return NULL;
}

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

	r1bio_pool_free(r1bio, data);
}

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

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

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

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

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

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	lower_barrier(conf);
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}

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

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

/*
 * raid_end_bio_io() is called when we have finished servicing a mirrored
 * operation and are ready to return a success/failure code to the buffer
 * cache layer.
 */
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static void call_bio_endio(struct r1bio *r1_bio)
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{
	struct bio *bio = r1_bio->master_bio;
	int done;
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	struct r1conf *conf = r1_bio->mddev->private;
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	sector_t start_next_window = r1_bio->start_next_window;
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	sector_t bi_sector = bio->bi_iter.bi_sector;
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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);
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		/*
		 * make_request() might be waiting for
		 * bi_phys_segments to decrease
		 */
		wake_up(&conf->wait_barrier);
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	} 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.
		 */
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		allow_barrier(conf, start_next_window, bi_sector);
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	}
}

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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",
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			 (unsigned long long) bio->bi_iter.bi_sector,
			 (unsigned long long) bio_end_sector(bio) - 1);
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		call_bio_endio(r1_bio);
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	}
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	free_r1bio(r1_bio);
}

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

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

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

	return mirror;
}

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

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

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

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

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

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

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

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		r1_bio->bios[mirror] = NULL;
		to_put = bio;
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		/*
		 * Do not set R1BIO_Uptodate if the current device is
		 * rebuilding or Faulty. This is because we cannot use
		 * such device for properly reading the data back (we could
		 * potentially use it, if the current write would have felt
		 * before rdev->recovery_offset, but for simplicity we don't
		 * check this here.
		 */
		if (test_bit(In_sync, &conf->mirrors[mirror].rdev->flags) &&
		    !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags))
			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",
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					 (unsigned long long) mbio->bi_iter.bi_sector,
					 (unsigned long long) bio_end_sector(mbio) - 1);
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				call_bio_endio(r1_bio);
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			}
		}
	}
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	if (r1_bio->bios[mirror] == NULL)
		rdev_dec_pending(conf->mirrors[mirror].rdev,
				 conf->mddev);
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	/*
	 * Let's see if all mirrored write operations have finished
	 * already.
	 */
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	r1_bio_write_done(r1_bio);
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	if (to_put)
		bio_put(to_put);
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}


/*
 * This routine returns the disk from which the requested read should
 * be done. There is a per-array 'next expected sequential IO' sector
 * number - if this matches on the next IO then we use the last disk.
 * There is also a per-disk 'last know head position' sector that is
 * maintained from IRQ contexts, both the normal and the resync IO
 * completion handlers update this position correctly. If there is no
 * perfect sequential match then we pick the disk whose head is closest.
 *
 * If there are 2 mirrors in the same 2 devices, performance degrades
 * because position is mirror, not device based.
 *
 * The rdev for the device selected will have nr_pending incremented.
 */
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static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
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{
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	const sector_t this_sector = r1_bio->sector;
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	int sectors;
	int best_good_sectors;
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	int best_disk, best_dist_disk, best_pending_disk;
	int has_nonrot_disk;
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	int disk;
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	sector_t best_dist;
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	unsigned int min_pending;
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	struct md_rdev *rdev;
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	int choose_first;
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	int choose_next_idle;
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	rcu_read_lock();
	/*
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	 * Check if we can balance. We can balance on the whole
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	 * device if no resync is going on, or below the resync window.
	 * We take the first readable disk when above the resync window.
	 */
 retry:
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	sectors = r1_bio->sectors;
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	best_disk = -1;
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	best_dist_disk = -1;
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	best_dist = MaxSector;
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	best_pending_disk = -1;
	min_pending = UINT_MAX;
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	best_good_sectors = 0;
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	has_nonrot_disk = 0;
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	choose_next_idle = 0;
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	if (conf->mddev->recovery_cp < MaxSector &&
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	    (this_sector + sectors >= conf->next_resync))
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		choose_first = 1;
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	else
538
		choose_first = 0;
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539

540
	for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
541
		sector_t dist;
542 543
		sector_t first_bad;
		int bad_sectors;
544
		unsigned int pending;
545
		bool nonrot;
546

547 548 549
		rdev = rcu_dereference(conf->mirrors[disk].rdev);
		if (r1_bio->bios[disk] == IO_BLOCKED
		    || rdev == NULL
550
		    || test_bit(Unmerged, &rdev->flags)
551
		    || test_bit(Faulty, &rdev->flags))
552
			continue;
553 554
		if (!test_bit(In_sync, &rdev->flags) &&
		    rdev->recovery_offset < this_sector + sectors)
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555
			continue;
556 557 558
		if (test_bit(WriteMostly, &rdev->flags)) {
			/* Don't balance among write-mostly, just
			 * use the first as a last resort */
559 560 561 562 563 564 565 566 567
			if (best_disk < 0) {
				if (is_badblock(rdev, this_sector, sectors,
						&first_bad, &bad_sectors)) {
					if (first_bad < this_sector)
						/* Cannot use this */
						continue;
					best_good_sectors = first_bad - this_sector;
				} else
					best_good_sectors = sectors;
568
				best_disk = disk;
569
			}
570 571 572 573 574
			continue;
		}
		/* This is a reasonable device to use.  It might
		 * even be best.
		 */
575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603
		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;

604 605
		nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev));
		has_nonrot_disk |= nonrot;
606
		pending = atomic_read(&rdev->nr_pending);
607
		dist = abs(this_sector - conf->mirrors[disk].head_position);
608
		if (choose_first) {
609
			best_disk = disk;
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610 611
			break;
		}
612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649
		/* Don't change to another disk for sequential reads */
		if (conf->mirrors[disk].next_seq_sect == this_sector
		    || dist == 0) {
			int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
			struct raid1_info *mirror = &conf->mirrors[disk];

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

		if (choose_next_idle)
			continue;
650 651 652 653 654 655

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

656 657
		if (dist < best_dist) {
			best_dist = dist;
658
			best_dist_disk = disk;
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659
		}
660
	}
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661

662 663 664 665 666 667 668 669 670 671 672 673 674
	/*
	 * If all disks are rotational, choose the closest disk. If any disk is
	 * non-rotational, choose the disk with less pending request even the
	 * disk is rotational, which might/might not be optimal for raids with
	 * mixed ratation/non-rotational disks depending on workload.
	 */
	if (best_disk == -1) {
		if (has_nonrot_disk)
			best_disk = best_pending_disk;
		else
			best_disk = best_dist_disk;
	}

675 676
	if (best_disk >= 0) {
		rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
677 678 679
		if (!rdev)
			goto retry;
		atomic_inc(&rdev->nr_pending);
680
		if (test_bit(Faulty, &rdev->flags)) {
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681 682 683
			/* cannot risk returning a device that failed
			 * before we inc'ed nr_pending
			 */
684
			rdev_dec_pending(rdev, conf->mddev);
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685 686
			goto retry;
		}
687
		sectors = best_good_sectors;
688 689 690 691

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

692
		conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
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693 694
	}
	rcu_read_unlock();
695
	*max_sectors = sectors;
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696

697
	return best_disk;
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698 699
}

700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732
static int raid1_mergeable_bvec(struct request_queue *q,
				struct bvec_merge_data *bvm,
				struct bio_vec *biovec)
{
	struct mddev *mddev = q->queuedata;
	struct r1conf *conf = mddev->private;
	sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
	int max = biovec->bv_len;

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

}

733
int md_raid1_congested(struct mddev *mddev, int bits)
734
{
735
	struct r1conf *conf = mddev->private;
736 737
	int i, ret = 0;

738 739 740 741
	if ((bits & (1 << BDI_async_congested)) &&
	    conf->pending_count >= max_queued_requests)
		return 1;

742
	rcu_read_lock();
743
	for (i = 0; i < conf->raid_disks * 2; i++) {
744
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
745
		if (rdev && !test_bit(Faulty, &rdev->flags)) {
746
			struct request_queue *q = bdev_get_queue(rdev->bdev);
747

748 749
			BUG_ON(!q);

750 751 752
			/* Note the '|| 1' - when read_balance prefers
			 * non-congested targets, it can be removed
			 */
753
			if ((bits & (1<<BDI_async_congested)) || 1)
754 755 756 757 758 759 760 761
				ret |= bdi_congested(&q->backing_dev_info, bits);
			else
				ret &= bdi_congested(&q->backing_dev_info, bits);
		}
	}
	rcu_read_unlock();
	return ret;
}
762
EXPORT_SYMBOL_GPL(md_raid1_congested);
763

764 765
static int raid1_congested(void *data, int bits)
{
766
	struct mddev *mddev = data;
767 768 769 770

	return mddev_congested(mddev, bits) ||
		md_raid1_congested(mddev, bits);
}
771

772
static void flush_pending_writes(struct r1conf *conf)
773 774 775 776 777 778 779 780 781
{
	/* 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);
782
		conf->pending_count = 0;
783 784 785 786
		spin_unlock_irq(&conf->device_lock);
		/* flush any pending bitmap writes to
		 * disk before proceeding w/ I/O */
		bitmap_unplug(conf->mddev->bitmap);
787
		wake_up(&conf->wait_barrier);
788 789 790 791

		while (bio) { /* submit pending writes */
			struct bio *next = bio->bi_next;
			bio->bi_next = NULL;
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Shaohua Li 已提交
792 793 794 795 796 797
			if (unlikely((bio->bi_rw & REQ_DISCARD) &&
			    !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
				/* Just ignore it */
				bio_endio(bio, 0);
			else
				generic_make_request(bio);
798 799 800 801
			bio = next;
		}
	} else
		spin_unlock_irq(&conf->device_lock);
802 803
}

804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823
/* 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.
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824
 */
825
static void raise_barrier(struct r1conf *conf)
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Linus Torvalds 已提交
826 827
{
	spin_lock_irq(&conf->resync_lock);
828 829 830

	/* Wait until no block IO is waiting */
	wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
831
			    conf->resync_lock);
832 833 834 835

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

836 837 838 839 840 841 842 843
	/* For these conditions we must wait:
	 * A: while the array is in frozen state
	 * B: while barrier >= RESYNC_DEPTH, meaning resync reach
	 *    the max count which allowed.
	 * C: next_resync + RESYNC_SECTORS > start_next_window, meaning
	 *    next resync will reach to the window which normal bios are
	 *    handling.
	 */
844
	wait_event_lock_irq(conf->wait_barrier,
845
			    !conf->array_frozen &&
846 847 848
			    conf->barrier < RESYNC_DEPTH &&
			    (conf->start_next_window >=
			     conf->next_resync + RESYNC_SECTORS),
849
			    conf->resync_lock);
850 851 852 853

	spin_unlock_irq(&conf->resync_lock);
}

854
static void lower_barrier(struct r1conf *conf)
855 856
{
	unsigned long flags;
857
	BUG_ON(conf->barrier <= 0);
858 859 860 861 862 863
	spin_lock_irqsave(&conf->resync_lock, flags);
	conf->barrier--;
	spin_unlock_irqrestore(&conf->resync_lock, flags);
	wake_up(&conf->wait_barrier);
}

864
static bool need_to_wait_for_sync(struct r1conf *conf, struct bio *bio)
865
{
866 867 868 869 870 871 872 873 874 875
	bool wait = false;

	if (conf->array_frozen || !bio)
		wait = true;
	else if (conf->barrier && bio_data_dir(bio) == WRITE) {
		if (conf->next_resync < RESYNC_WINDOW_SECTORS)
			wait = true;
		else if ((conf->next_resync - RESYNC_WINDOW_SECTORS
				>= bio_end_sector(bio)) ||
			 (conf->next_resync + NEXT_NORMALIO_DISTANCE
876
				<= bio->bi_iter.bi_sector))
877 878 879 880 881 882 883 884 885 886 887 888
			wait = false;
		else
			wait = true;
	}

	return wait;
}

static sector_t wait_barrier(struct r1conf *conf, struct bio *bio)
{
	sector_t sector = 0;

889
	spin_lock_irq(&conf->resync_lock);
890
	if (need_to_wait_for_sync(conf, bio)) {
891
		conf->nr_waiting++;
892 893 894 895 896 897 898 899 900 901
		/* Wait for the barrier to drop.
		 * However if there are already pending
		 * requests (preventing the barrier from
		 * rising completely), and the
		 * pre-process bio queue isn't empty,
		 * then don't wait, as we need to empty
		 * that queue to get the nr_pending
		 * count down.
		 */
		wait_event_lock_irq(conf->wait_barrier,
902 903
				    !conf->array_frozen &&
				    (!conf->barrier ||
904 905
				    ((conf->start_next_window <
				      conf->next_resync + RESYNC_SECTORS) &&
906
				     current->bio_list &&
907
				     !bio_list_empty(current->bio_list))),
908
				    conf->resync_lock);
909
		conf->nr_waiting--;
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Linus Torvalds 已提交
910
	}
911 912 913

	if (bio && bio_data_dir(bio) == WRITE) {
		if (conf->next_resync + NEXT_NORMALIO_DISTANCE
914
		    <= bio->bi_iter.bi_sector) {
915 916 917 918 919 920
			if (conf->start_next_window == MaxSector)
				conf->start_next_window =
					conf->next_resync +
					NEXT_NORMALIO_DISTANCE;

			if ((conf->start_next_window + NEXT_NORMALIO_DISTANCE)
921
			    <= bio->bi_iter.bi_sector)
922 923 924 925
				conf->next_window_requests++;
			else
				conf->current_window_requests++;
		}
926
		if (bio->bi_iter.bi_sector >= conf->start_next_window)
927 928 929
			sector = conf->start_next_window;
	}

930
	conf->nr_pending++;
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Linus Torvalds 已提交
931
	spin_unlock_irq(&conf->resync_lock);
932
	return sector;
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Linus Torvalds 已提交
933 934
}

935 936
static void allow_barrier(struct r1conf *conf, sector_t start_next_window,
			  sector_t bi_sector)
937 938
{
	unsigned long flags;
939

940 941
	spin_lock_irqsave(&conf->resync_lock, flags);
	conf->nr_pending--;
942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962
	if (start_next_window) {
		if (start_next_window == conf->start_next_window) {
			if (conf->start_next_window + NEXT_NORMALIO_DISTANCE
			    <= bi_sector)
				conf->next_window_requests--;
			else
				conf->current_window_requests--;
		} else
			conf->current_window_requests--;

		if (!conf->current_window_requests) {
			if (conf->next_window_requests) {
				conf->current_window_requests =
					conf->next_window_requests;
				conf->next_window_requests = 0;
				conf->start_next_window +=
					NEXT_NORMALIO_DISTANCE;
			} else
				conf->start_next_window = MaxSector;
		}
	}
963 964 965 966
	spin_unlock_irqrestore(&conf->resync_lock, flags);
	wake_up(&conf->wait_barrier);
}

967
static void freeze_array(struct r1conf *conf, int extra)
968 969 970
{
	/* stop syncio and normal IO and wait for everything to
	 * go quite.
971
	 * We wait until nr_pending match nr_queued+extra
972 973 974 975
	 * 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.
976
	 * Thus the number queued (nr_queued) plus this request (extra)
977 978
	 * must match the number of pending IOs (nr_pending) before
	 * we continue.
979 980
	 */
	spin_lock_irq(&conf->resync_lock);
981
	conf->array_frozen = 1;
982
	wait_event_lock_irq_cmd(conf->wait_barrier,
983
				conf->nr_pending == conf->nr_queued+extra,
984 985
				conf->resync_lock,
				flush_pending_writes(conf));
986 987
	spin_unlock_irq(&conf->resync_lock);
}
988
static void unfreeze_array(struct r1conf *conf)
989 990 991
{
	/* reverse the effect of the freeze */
	spin_lock_irq(&conf->resync_lock);
992
	conf->array_frozen = 0;
993 994 995 996
	wake_up(&conf->wait_barrier);
	spin_unlock_irq(&conf->resync_lock);
}

997

998 999
/* duplicate the data pages for behind I/O 
 */
1000
static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
1001 1002 1003
{
	int i;
	struct bio_vec *bvec;
1004
	struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
1005
					GFP_NOIO);
1006
	if (unlikely(!bvecs))
1007
		return;
1008

1009
	bio_for_each_segment_all(bvec, bio, i) {
1010 1011 1012
		bvecs[i] = *bvec;
		bvecs[i].bv_page = alloc_page(GFP_NOIO);
		if (unlikely(!bvecs[i].bv_page))
1013
			goto do_sync_io;
1014 1015 1016
		memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
		       kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
		kunmap(bvecs[i].bv_page);
1017 1018
		kunmap(bvec->bv_page);
	}
1019
	r1_bio->behind_bvecs = bvecs;
1020 1021 1022
	r1_bio->behind_page_count = bio->bi_vcnt;
	set_bit(R1BIO_BehindIO, &r1_bio->state);
	return;
1023 1024

do_sync_io:
1025
	for (i = 0; i < bio->bi_vcnt; i++)
1026 1027 1028
		if (bvecs[i].bv_page)
			put_page(bvecs[i].bv_page);
	kfree(bvecs);
1029 1030
	pr_debug("%dB behind alloc failed, doing sync I/O\n",
		 bio->bi_iter.bi_size);
1031 1032
}

1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046
struct raid1_plug_cb {
	struct blk_plug_cb	cb;
	struct bio_list		pending;
	int			pending_cnt;
};

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

1047
	if (from_schedule || current->bio_list) {
1048 1049 1050 1051
		spin_lock_irq(&conf->device_lock);
		bio_list_merge(&conf->pending_bio_list, &plug->pending);
		conf->pending_count += plug->pending_cnt;
		spin_unlock_irq(&conf->device_lock);
1052
		wake_up(&conf->wait_barrier);
1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
		md_wakeup_thread(mddev->thread);
		kfree(plug);
		return;
	}

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

	while (bio) { /* submit pending writes */
		struct bio *next = bio->bi_next;
		bio->bi_next = NULL;
1066 1067 1068 1069 1070 1071
		if (unlikely((bio->bi_rw & REQ_DISCARD) &&
		    !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
			/* Just ignore it */
			bio_endio(bio, 0);
		else
			generic_make_request(bio);
1072 1073 1074 1075 1076
		bio = next;
	}
	kfree(plug);
}

1077
static void make_request(struct mddev *mddev, struct bio * bio)
L
Linus Torvalds 已提交
1078
{
1079
	struct r1conf *conf = mddev->private;
1080
	struct raid1_info *mirror;
1081
	struct r1bio *r1_bio;
L
Linus Torvalds 已提交
1082
	struct bio *read_bio;
1083
	int i, disks;
1084
	struct bitmap *bitmap;
1085
	unsigned long flags;
1086
	const int rw = bio_data_dir(bio);
1087
	const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
1088
	const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
S
Shaohua Li 已提交
1089 1090
	const unsigned long do_discard = (bio->bi_rw
					  & (REQ_DISCARD | REQ_SECURE));
1091
	const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME);
1092
	struct md_rdev *blocked_rdev;
1093 1094
	struct blk_plug_cb *cb;
	struct raid1_plug_cb *plug = NULL;
1095 1096 1097
	int first_clone;
	int sectors_handled;
	int max_sectors;
1098
	sector_t start_next_window;
1099

L
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1100 1101 1102 1103 1104
	/*
	 * 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.
	 */
1105

1106 1107
	md_write_start(mddev, bio); /* wait on superblock update early */

1108
	if (bio_data_dir(bio) == WRITE &&
1109
	    bio_end_sector(bio) > mddev->suspend_lo &&
1110
	    bio->bi_iter.bi_sector < mddev->suspend_hi) {
1111 1112 1113 1114 1115 1116 1117 1118 1119
		/* 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);
1120
			if (bio_end_sector(bio) <= mddev->suspend_lo ||
1121
			    bio->bi_iter.bi_sector >= mddev->suspend_hi)
1122 1123 1124 1125 1126
				break;
			schedule();
		}
		finish_wait(&conf->wait_barrier, &w);
	}
1127

1128
	start_next_window = wait_barrier(conf, bio);
L
Linus Torvalds 已提交
1129

1130 1131
	bitmap = mddev->bitmap;

L
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1132 1133 1134 1135 1136 1137 1138 1139
	/*
	 * 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;
1140
	r1_bio->sectors = bio_sectors(bio);
1141
	r1_bio->state = 0;
L
Linus Torvalds 已提交
1142
	r1_bio->mddev = mddev;
1143
	r1_bio->sector = bio->bi_iter.bi_sector;
L
Linus Torvalds 已提交
1144

1145 1146 1147 1148 1149 1150 1151 1152 1153 1154
	/* 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);

1155
	if (rw == READ) {
L
Linus Torvalds 已提交
1156 1157 1158
		/*
		 * read balancing logic:
		 */
1159 1160 1161 1162
		int rdisk;

read_again:
		rdisk = read_balance(conf, r1_bio, &max_sectors);
L
Linus Torvalds 已提交
1163 1164 1165 1166

		if (rdisk < 0) {
			/* couldn't find anywhere to read from */
			raid_end_bio_io(r1_bio);
1167
			return;
L
Linus Torvalds 已提交
1168 1169 1170
		}
		mirror = conf->mirrors + rdisk;

1171 1172 1173 1174 1175 1176 1177 1178 1179
		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
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1180 1181
		r1_bio->read_disk = rdisk;

1182
		read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1183
		bio_trim(read_bio, r1_bio->sector - bio->bi_iter.bi_sector,
1184
			 max_sectors);
L
Linus Torvalds 已提交
1185 1186 1187

		r1_bio->bios[rdisk] = read_bio;

1188 1189
		read_bio->bi_iter.bi_sector = r1_bio->sector +
			mirror->rdev->data_offset;
L
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1190 1191
		read_bio->bi_bdev = mirror->rdev->bdev;
		read_bio->bi_end_io = raid1_end_read_request;
1192
		read_bio->bi_rw = READ | do_sync;
L
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1193 1194
		read_bio->bi_private = r1_bio;

1195 1196 1197 1198 1199 1200
		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
1201
					   - bio->bi_iter.bi_sector);
1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218
			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;
1219
			r1_bio->sectors = bio_sectors(bio) - sectors_handled;
1220 1221
			r1_bio->state = 0;
			r1_bio->mddev = mddev;
1222 1223
			r1_bio->sector = bio->bi_iter.bi_sector +
				sectors_handled;
1224 1225 1226
			goto read_again;
		} else
			generic_make_request(read_bio);
1227
		return;
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1228 1229 1230 1231 1232
	}

	/*
	 * WRITE:
	 */
1233 1234 1235 1236 1237
	if (conf->pending_count >= max_queued_requests) {
		md_wakeup_thread(mddev->thread);
		wait_event(conf->wait_barrier,
			   conf->pending_count < max_queued_requests);
	}
1238
	/* first select target devices under rcu_lock and
L
Linus Torvalds 已提交
1239 1240
	 * inc refcount on their rdev.  Record them by setting
	 * bios[x] to bio
1241 1242 1243 1244 1245 1246
	 * 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
1247
	 */
1248

1249
	disks = conf->raid_disks * 2;
1250
 retry_write:
1251
	r1_bio->start_next_window = start_next_window;
1252
	blocked_rdev = NULL;
L
Linus Torvalds 已提交
1253
	rcu_read_lock();
1254
	max_sectors = r1_bio->sectors;
L
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1255
	for (i = 0;  i < disks; i++) {
1256
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1257 1258 1259 1260 1261
		if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
			atomic_inc(&rdev->nr_pending);
			blocked_rdev = rdev;
			break;
		}
1262
		r1_bio->bios[i] = NULL;
1263 1264
		if (!rdev || test_bit(Faulty, &rdev->flags)
		    || test_bit(Unmerged, &rdev->flags)) {
1265 1266
			if (i < conf->raid_disks)
				set_bit(R1BIO_Degraded, &r1_bio->state);
1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293
			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;
1294
				rdev_dec_pending(rdev, mddev);
1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305
				/* 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;
1306
			}
1307 1308 1309 1310 1311 1312 1313
			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
1314 1315 1316
	}
	rcu_read_unlock();

1317 1318 1319
	if (unlikely(blocked_rdev)) {
		/* Wait for this device to become unblocked */
		int j;
1320
		sector_t old = start_next_window;
1321 1322 1323 1324

		for (j = 0; j < i; j++)
			if (r1_bio->bios[j])
				rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1325
		r1_bio->state = 0;
1326
		allow_barrier(conf, start_next_window, bio->bi_iter.bi_sector);
1327
		md_wait_for_blocked_rdev(blocked_rdev, mddev);
1328 1329 1330 1331 1332 1333 1334 1335 1336 1337
		start_next_window = wait_barrier(conf, bio);
		/*
		 * We must make sure the multi r1bios of bio have
		 * the same value of bi_phys_segments
		 */
		if (bio->bi_phys_segments && old &&
		    old != start_next_window)
			/* Wait for the former r1bio(s) to complete */
			wait_event(conf->wait_barrier,
				   bio->bi_phys_segments == 1);
1338 1339 1340
		goto retry_write;
	}

1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351
	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);
1352
	}
1353
	sectors_handled = r1_bio->sector + max_sectors - bio->bi_iter.bi_sector;
1354

1355
	atomic_set(&r1_bio->remaining, 1);
1356
	atomic_set(&r1_bio->behind_remaining, 0);
1357

1358
	first_clone = 1;
L
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1359 1360 1361 1362 1363
	for (i = 0; i < disks; i++) {
		struct bio *mbio;
		if (!r1_bio->bios[i])
			continue;

1364
		mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1365
		bio_trim(mbio, r1_bio->sector - bio->bi_iter.bi_sector, max_sectors);
1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383

		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;
		}
1384
		if (r1_bio->behind_bvecs) {
1385 1386 1387
			struct bio_vec *bvec;
			int j;

1388 1389
			/*
			 * We trimmed the bio, so _all is legit
1390
			 */
1391
			bio_for_each_segment_all(bvec, mbio, j)
1392
				bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1393 1394 1395 1396
			if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
				atomic_inc(&r1_bio->behind_remaining);
		}

1397 1398
		r1_bio->bios[i] = mbio;

1399
		mbio->bi_iter.bi_sector	= (r1_bio->sector +
1400 1401 1402
				   conf->mirrors[i].rdev->data_offset);
		mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
		mbio->bi_end_io	= raid1_end_write_request;
1403 1404
		mbio->bi_rw =
			WRITE | do_flush_fua | do_sync | do_discard | do_same;
1405 1406
		mbio->bi_private = r1_bio;

L
Linus Torvalds 已提交
1407
		atomic_inc(&r1_bio->remaining);
1408 1409 1410 1411 1412 1413

		cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
		if (cb)
			plug = container_of(cb, struct raid1_plug_cb, cb);
		else
			plug = NULL;
1414
		spin_lock_irqsave(&conf->device_lock, flags);
1415 1416 1417 1418 1419 1420 1421
		if (plug) {
			bio_list_add(&plug->pending, mbio);
			plug->pending_cnt++;
		} else {
			bio_list_add(&conf->pending_bio_list, mbio);
			conf->pending_count++;
		}
1422
		spin_unlock_irqrestore(&conf->device_lock, flags);
1423
		if (!plug)
N
NeilBrown 已提交
1424
			md_wakeup_thread(mddev->thread);
L
Linus Torvalds 已提交
1425
	}
1426 1427 1428
	/* Mustn't call r1_bio_write_done before this next test,
	 * as it could result in the bio being freed.
	 */
1429
	if (sectors_handled < bio_sectors(bio)) {
1430
		r1_bio_write_done(r1_bio);
1431 1432 1433 1434 1435
		/* 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;
1436
		r1_bio->sectors = bio_sectors(bio) - sectors_handled;
1437 1438
		r1_bio->state = 0;
		r1_bio->mddev = mddev;
1439
		r1_bio->sector = bio->bi_iter.bi_sector + sectors_handled;
1440 1441 1442
		goto retry_write;
	}

1443 1444 1445 1446
	r1_bio_write_done(r1_bio);

	/* In case raid1d snuck in to freeze_array */
	wake_up(&conf->wait_barrier);
L
Linus Torvalds 已提交
1447 1448
}

1449
static void status(struct seq_file *seq, struct mddev *mddev)
L
Linus Torvalds 已提交
1450
{
1451
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1452 1453 1454
	int i;

	seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1455
		   conf->raid_disks - mddev->degraded);
1456 1457
	rcu_read_lock();
	for (i = 0; i < conf->raid_disks; i++) {
1458
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
L
Linus Torvalds 已提交
1459
		seq_printf(seq, "%s",
1460 1461 1462
			   rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
	}
	rcu_read_unlock();
L
Linus Torvalds 已提交
1463 1464 1465 1466
	seq_printf(seq, "]");
}


1467
static void error(struct mddev *mddev, struct md_rdev *rdev)
L
Linus Torvalds 已提交
1468 1469
{
	char b[BDEVNAME_SIZE];
1470
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1471 1472 1473 1474 1475 1476 1477

	/*
	 * 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
	 */
1478
	if (test_bit(In_sync, &rdev->flags)
1479
	    && (conf->raid_disks - mddev->degraded) == 1) {
L
Linus Torvalds 已提交
1480 1481
		/*
		 * Don't fail the drive, act as though we were just a
1482 1483 1484
		 * 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
1485
		 */
1486
		conf->recovery_disabled = mddev->recovery_disabled;
L
Linus Torvalds 已提交
1487
		return;
1488
	}
1489
	set_bit(Blocked, &rdev->flags);
1490 1491 1492
	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
1493
		mddev->degraded++;
1494
		set_bit(Faulty, &rdev->flags);
1495
		spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
1496 1497 1498
		/*
		 * if recovery is running, make sure it aborts.
		 */
1499
		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1500 1501
	} else
		set_bit(Faulty, &rdev->flags);
1502
	set_bit(MD_CHANGE_DEVS, &mddev->flags);
1503 1504 1505
	printk(KERN_ALERT
	       "md/raid1:%s: Disk failure on %s, disabling device.\n"
	       "md/raid1:%s: Operation continuing on %d devices.\n",
1506 1507
	       mdname(mddev), bdevname(rdev->bdev, b),
	       mdname(mddev), conf->raid_disks - mddev->degraded);
L
Linus Torvalds 已提交
1508 1509
}

1510
static void print_conf(struct r1conf *conf)
L
Linus Torvalds 已提交
1511 1512 1513
{
	int i;

1514
	printk(KERN_DEBUG "RAID1 conf printout:\n");
L
Linus Torvalds 已提交
1515
	if (!conf) {
1516
		printk(KERN_DEBUG "(!conf)\n");
L
Linus Torvalds 已提交
1517 1518
		return;
	}
1519
	printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
L
Linus Torvalds 已提交
1520 1521
		conf->raid_disks);

1522
	rcu_read_lock();
L
Linus Torvalds 已提交
1523 1524
	for (i = 0; i < conf->raid_disks; i++) {
		char b[BDEVNAME_SIZE];
1525
		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1526
		if (rdev)
1527
			printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1528 1529 1530
			       i, !test_bit(In_sync, &rdev->flags),
			       !test_bit(Faulty, &rdev->flags),
			       bdevname(rdev->bdev,b));
L
Linus Torvalds 已提交
1531
	}
1532
	rcu_read_unlock();
L
Linus Torvalds 已提交
1533 1534
}

1535
static void close_sync(struct r1conf *conf)
L
Linus Torvalds 已提交
1536
{
1537 1538
	wait_barrier(conf, NULL);
	allow_barrier(conf, 0, 0);
L
Linus Torvalds 已提交
1539 1540 1541

	mempool_destroy(conf->r1buf_pool);
	conf->r1buf_pool = NULL;
1542 1543 1544

	conf->next_resync = 0;
	conf->start_next_window = MaxSector;
L
Linus Torvalds 已提交
1545 1546
}

1547
static int raid1_spare_active(struct mddev *mddev)
L
Linus Torvalds 已提交
1548 1549
{
	int i;
1550
	struct r1conf *conf = mddev->private;
1551 1552
	int count = 0;
	unsigned long flags;
L
Linus Torvalds 已提交
1553 1554 1555

	/*
	 * Find all failed disks within the RAID1 configuration 
1556 1557
	 * and mark them readable.
	 * Called under mddev lock, so rcu protection not needed.
L
Linus Torvalds 已提交
1558 1559
	 */
	for (i = 0; i < conf->raid_disks; i++) {
1560
		struct md_rdev *rdev = conf->mirrors[i].rdev;
1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579
		struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
		if (repl
		    && repl->recovery_offset == MaxSector
		    && !test_bit(Faulty, &repl->flags)
		    && !test_and_set_bit(In_sync, &repl->flags)) {
			/* replacement has just become active */
			if (!rdev ||
			    !test_and_clear_bit(In_sync, &rdev->flags))
				count++;
			if (rdev) {
				/* Replaced device not technically
				 * faulty, but we need to be sure
				 * it gets removed and never re-added
				 */
				set_bit(Faulty, &rdev->flags);
				sysfs_notify_dirent_safe(
					rdev->sysfs_state);
			}
		}
1580
		if (rdev
1581
		    && rdev->recovery_offset == MaxSector
1582
		    && !test_bit(Faulty, &rdev->flags)
1583
		    && !test_and_set_bit(In_sync, &rdev->flags)) {
1584
			count++;
1585
			sysfs_notify_dirent_safe(rdev->sysfs_state);
L
Linus Torvalds 已提交
1586 1587
		}
	}
1588 1589 1590
	spin_lock_irqsave(&conf->device_lock, flags);
	mddev->degraded -= count;
	spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
1591 1592

	print_conf(conf);
1593
	return count;
L
Linus Torvalds 已提交
1594 1595 1596
}


1597
static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
L
Linus Torvalds 已提交
1598
{
1599
	struct r1conf *conf = mddev->private;
1600
	int err = -EEXIST;
1601
	int mirror = 0;
1602
	struct raid1_info *p;
1603
	int first = 0;
1604
	int last = conf->raid_disks - 1;
1605
	struct request_queue *q = bdev_get_queue(rdev->bdev);
L
Linus Torvalds 已提交
1606

1607 1608 1609
	if (mddev->recovery_disabled == conf->recovery_disabled)
		return -EBUSY;

1610 1611 1612
	if (rdev->raid_disk >= 0)
		first = last = rdev->raid_disk;

1613 1614 1615 1616 1617
	if (q->merge_bvec_fn) {
		set_bit(Unmerged, &rdev->flags);
		mddev->merge_check_needed = 1;
	}

1618 1619 1620
	for (mirror = first; mirror <= last; mirror++) {
		p = conf->mirrors+mirror;
		if (!p->rdev) {
L
Linus Torvalds 已提交
1621

1622 1623 1624
			if (mddev->gendisk)
				disk_stack_limits(mddev->gendisk, rdev->bdev,
						  rdev->data_offset << 9);
L
Linus Torvalds 已提交
1625 1626 1627

			p->head_position = 0;
			rdev->raid_disk = mirror;
1628
			err = 0;
1629 1630 1631 1632
			/* 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)
1633
				conf->fullsync = 1;
1634
			rcu_assign_pointer(p->rdev, rdev);
L
Linus Torvalds 已提交
1635 1636
			break;
		}
1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648
		if (test_bit(WantReplacement, &p->rdev->flags) &&
		    p[conf->raid_disks].rdev == NULL) {
			/* Add this device as a replacement */
			clear_bit(In_sync, &rdev->flags);
			set_bit(Replacement, &rdev->flags);
			rdev->raid_disk = mirror;
			err = 0;
			conf->fullsync = 1;
			rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
			break;
		}
	}
1649 1650 1651 1652 1653 1654 1655 1656 1657
	if (err == 0 && test_bit(Unmerged, &rdev->flags)) {
		/* Some requests might not have seen this new
		 * merge_bvec_fn.  We must wait for them to complete
		 * before merging the device fully.
		 * First we make sure any code which has tested
		 * our function has submitted the request, then
		 * we wait for all outstanding requests to complete.
		 */
		synchronize_sched();
1658 1659
		freeze_array(conf, 0);
		unfreeze_array(conf);
1660 1661
		clear_bit(Unmerged, &rdev->flags);
	}
1662
	md_integrity_add_rdev(rdev, mddev);
1663
	if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
S
Shaohua Li 已提交
1664
		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
L
Linus Torvalds 已提交
1665
	print_conf(conf);
1666
	return err;
L
Linus Torvalds 已提交
1667 1668
}

1669
static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
L
Linus Torvalds 已提交
1670
{
1671
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1672
	int err = 0;
1673
	int number = rdev->raid_disk;
1674
	struct raid1_info *p = conf->mirrors + number;
L
Linus Torvalds 已提交
1675

1676 1677 1678
	if (rdev != p->rdev)
		p = conf->mirrors + conf->raid_disks + number;

L
Linus Torvalds 已提交
1679
	print_conf(conf);
1680
	if (rdev == p->rdev) {
1681
		if (test_bit(In_sync, &rdev->flags) ||
L
Linus Torvalds 已提交
1682 1683 1684 1685
		    atomic_read(&rdev->nr_pending)) {
			err = -EBUSY;
			goto abort;
		}
1686
		/* Only remove non-faulty devices if recovery
1687 1688 1689
		 * is not possible.
		 */
		if (!test_bit(Faulty, &rdev->flags) &&
1690
		    mddev->recovery_disabled != conf->recovery_disabled &&
1691 1692 1693 1694
		    mddev->degraded < conf->raid_disks) {
			err = -EBUSY;
			goto abort;
		}
L
Linus Torvalds 已提交
1695
		p->rdev = NULL;
1696
		synchronize_rcu();
L
Linus Torvalds 已提交
1697 1698 1699 1700
		if (atomic_read(&rdev->nr_pending)) {
			/* lost the race, try later */
			err = -EBUSY;
			p->rdev = rdev;
1701
			goto abort;
1702 1703 1704 1705 1706 1707 1708
		} else if (conf->mirrors[conf->raid_disks + number].rdev) {
			/* We just removed a device that is being replaced.
			 * Move down the replacement.  We drain all IO before
			 * doing this to avoid confusion.
			 */
			struct md_rdev *repl =
				conf->mirrors[conf->raid_disks + number].rdev;
1709
			freeze_array(conf, 0);
1710 1711 1712
			clear_bit(Replacement, &repl->flags);
			p->rdev = repl;
			conf->mirrors[conf->raid_disks + number].rdev = NULL;
1713
			unfreeze_array(conf);
1714 1715
			clear_bit(WantReplacement, &rdev->flags);
		} else
1716
			clear_bit(WantReplacement, &rdev->flags);
1717
		err = md_integrity_register(mddev);
L
Linus Torvalds 已提交
1718 1719 1720 1721 1722 1723 1724 1725
	}
abort:

	print_conf(conf);
	return err;
}


1726
static void end_sync_read(struct bio *bio, int error)
L
Linus Torvalds 已提交
1727
{
1728
	struct r1bio *r1_bio = bio->bi_private;
L
Linus Torvalds 已提交
1729

1730
	update_head_pos(r1_bio->read_disk, r1_bio);
1731

L
Linus Torvalds 已提交
1732 1733 1734 1735 1736
	/*
	 * 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
	 */
1737
	if (test_bit(BIO_UPTODATE, &bio->bi_flags))
L
Linus Torvalds 已提交
1738
		set_bit(R1BIO_Uptodate, &r1_bio->state);
1739 1740 1741

	if (atomic_dec_and_test(&r1_bio->remaining))
		reschedule_retry(r1_bio);
L
Linus Torvalds 已提交
1742 1743
}

1744
static void end_sync_write(struct bio *bio, int error)
L
Linus Torvalds 已提交
1745 1746
{
	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1747
	struct r1bio *r1_bio = bio->bi_private;
1748
	struct mddev *mddev = r1_bio->mddev;
1749
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
1750
	int mirror=0;
1751 1752
	sector_t first_bad;
	int bad_sectors;
L
Linus Torvalds 已提交
1753

1754 1755
	mirror = find_bio_disk(r1_bio, bio);

1756
	if (!uptodate) {
1757
		sector_t sync_blocks = 0;
1758 1759 1760 1761
		sector_t s = r1_bio->sector;
		long sectors_to_go = r1_bio->sectors;
		/* make sure these bits doesn't get cleared. */
		do {
1762
			bitmap_end_sync(mddev->bitmap, s,
1763 1764 1765 1766
					&sync_blocks, 1);
			s += sync_blocks;
			sectors_to_go -= sync_blocks;
		} while (sectors_to_go > 0);
1767 1768
		set_bit(WriteErrorSeen,
			&conf->mirrors[mirror].rdev->flags);
1769 1770 1771 1772
		if (!test_and_set_bit(WantReplacement,
				      &conf->mirrors[mirror].rdev->flags))
			set_bit(MD_RECOVERY_NEEDED, &
				mddev->recovery);
1773
		set_bit(R1BIO_WriteError, &r1_bio->state);
1774 1775 1776
	} else if (is_badblock(conf->mirrors[mirror].rdev,
			       r1_bio->sector,
			       r1_bio->sectors,
1777 1778 1779 1780 1781 1782
			       &first_bad, &bad_sectors) &&
		   !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
				r1_bio->sector,
				r1_bio->sectors,
				&first_bad, &bad_sectors)
		)
1783
		set_bit(R1BIO_MadeGood, &r1_bio->state);
1784

L
Linus Torvalds 已提交
1785
	if (atomic_dec_and_test(&r1_bio->remaining)) {
1786
		int s = r1_bio->sectors;
1787 1788
		if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
		    test_bit(R1BIO_WriteError, &r1_bio->state))
1789 1790 1791 1792 1793
			reschedule_retry(r1_bio);
		else {
			put_buf(r1_bio);
			md_done_sync(mddev, s, uptodate);
		}
L
Linus Torvalds 已提交
1794 1795 1796
	}
}

1797
static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1798 1799 1800 1801 1802
			    int sectors, struct page *page, int rw)
{
	if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
		/* success */
		return 1;
1803
	if (rw == WRITE) {
1804
		set_bit(WriteErrorSeen, &rdev->flags);
1805 1806 1807 1808 1809
		if (!test_and_set_bit(WantReplacement,
				      &rdev->flags))
			set_bit(MD_RECOVERY_NEEDED, &
				rdev->mddev->recovery);
	}
1810 1811 1812 1813 1814 1815
	/* 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;
}

1816
static int fix_sync_read_error(struct r1bio *r1_bio)
L
Linus Torvalds 已提交
1817
{
1818 1819 1820 1821 1822 1823 1824
	/* 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.
1825 1826 1827
	 * 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.
1828
	 */
1829
	struct mddev *mddev = r1_bio->mddev;
1830
	struct r1conf *conf = mddev->private;
1831 1832 1833 1834 1835 1836 1837 1838 1839
	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;
1840
		struct md_rdev *rdev;
1841
		int start;
1842 1843 1844 1845 1846 1847 1848 1849 1850 1851

		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;
1852
				if (sync_page_io(rdev, sect, s<<9,
1853 1854 1855 1856 1857 1858 1859
						 bio->bi_io_vec[idx].bv_page,
						 READ, false)) {
					success = 1;
					break;
				}
			}
			d++;
1860
			if (d == conf->raid_disks * 2)
1861 1862 1863
				d = 0;
		} while (!success && d != r1_bio->read_disk);

1864
		if (!success) {
1865
			char b[BDEVNAME_SIZE];
1866 1867 1868 1869 1870 1871
			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.
			 */
1872 1873 1874 1875 1876
			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);
1877
			for (d = 0; d < conf->raid_disks * 2; d++) {
1878 1879 1880 1881 1882 1883 1884
				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) {
1885 1886
				conf->recovery_disabled =
					mddev->recovery_disabled;
1887 1888 1889 1890 1891 1892 1893 1894 1895 1896
				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;
1897
		}
1898 1899 1900 1901 1902

		start = d;
		/* write it back and re-read */
		while (d != r1_bio->read_disk) {
			if (d == 0)
1903
				d = conf->raid_disks * 2;
1904 1905 1906 1907
			d--;
			if (r1_bio->bios[d]->bi_end_io != end_sync_read)
				continue;
			rdev = conf->mirrors[d].rdev;
1908 1909 1910
			if (r1_sync_page_io(rdev, sect, s,
					    bio->bi_io_vec[idx].bv_page,
					    WRITE) == 0) {
1911 1912
				r1_bio->bios[d]->bi_end_io = NULL;
				rdev_dec_pending(rdev, mddev);
1913
			}
1914 1915 1916 1917
		}
		d = start;
		while (d != r1_bio->read_disk) {
			if (d == 0)
1918
				d = conf->raid_disks * 2;
1919 1920 1921 1922
			d--;
			if (r1_bio->bios[d]->bi_end_io != end_sync_read)
				continue;
			rdev = conf->mirrors[d].rdev;
1923 1924 1925
			if (r1_sync_page_io(rdev, sect, s,
					    bio->bi_io_vec[idx].bv_page,
					    READ) != 0)
1926
				atomic_add(s, &rdev->corrected_errors);
1927
		}
1928 1929 1930 1931
		sectors -= s;
		sect += s;
		idx ++;
	}
1932
	set_bit(R1BIO_Uptodate, &r1_bio->state);
1933
	set_bit(BIO_UPTODATE, &bio->bi_flags);
1934 1935 1936
	return 1;
}

1937
static int process_checks(struct r1bio *r1_bio)
1938 1939 1940 1941 1942 1943 1944 1945
{
	/* 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
	 */
1946
	struct mddev *mddev = r1_bio->mddev;
1947
	struct r1conf *conf = mddev->private;
1948 1949
	int primary;
	int i;
1950
	int vcnt;
1951

1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962
	/* Fix variable parts of all bios */
	vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
	for (i = 0; i < conf->raid_disks * 2; i++) {
		int j;
		int size;
		struct bio *b = r1_bio->bios[i];
		if (b->bi_end_io != end_sync_read)
			continue;
		/* fixup the bio for reuse */
		bio_reset(b);
		b->bi_vcnt = vcnt;
1963 1964
		b->bi_iter.bi_size = r1_bio->sectors << 9;
		b->bi_iter.bi_sector = r1_bio->sector +
1965 1966 1967 1968 1969
			conf->mirrors[i].rdev->data_offset;
		b->bi_bdev = conf->mirrors[i].rdev->bdev;
		b->bi_end_io = end_sync_read;
		b->bi_private = r1_bio;

1970
		size = b->bi_iter.bi_size;
1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981
		for (j = 0; j < vcnt ; j++) {
			struct bio_vec *bi;
			bi = &b->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;
		}
	}
1982
	for (primary = 0; primary < conf->raid_disks * 2; primary++)
1983 1984 1985 1986 1987 1988 1989
		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;
1990
	for (i = 0; i < conf->raid_disks * 2; i++) {
1991 1992 1993
		int j;
		struct bio *pbio = r1_bio->bios[primary];
		struct bio *sbio = r1_bio->bios[i];
1994

K
Kent Overstreet 已提交
1995
		if (sbio->bi_end_io != end_sync_read)
1996 1997 1998 1999 2000 2001 2002 2003 2004
			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),
2005
					   sbio->bi_io_vec[j].bv_len))
2006
					break;
2007
			}
2008 2009 2010
		} else
			j = 0;
		if (j >= 0)
2011
			atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
2012 2013 2014 2015 2016 2017 2018
		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;
		}
2019 2020

		bio_copy_data(sbio, pbio);
2021
	}
2022 2023 2024
	return 0;
}

2025
static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
2026
{
2027
	struct r1conf *conf = mddev->private;
2028
	int i;
2029
	int disks = conf->raid_disks * 2;
2030 2031 2032 2033 2034 2035 2036 2037
	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;
2038 2039 2040 2041

	if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
		if (process_checks(r1_bio) < 0)
			return;
2042 2043 2044
	/*
	 * schedule writes
	 */
L
Linus Torvalds 已提交
2045 2046 2047
	atomic_set(&r1_bio->remaining, 1);
	for (i = 0; i < disks ; i++) {
		wbio = r1_bio->bios[i];
2048 2049 2050 2051
		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
2052 2053
			continue;

2054 2055
		wbio->bi_rw = WRITE;
		wbio->bi_end_io = end_sync_write;
L
Linus Torvalds 已提交
2056
		atomic_inc(&r1_bio->remaining);
2057
		md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
2058

L
Linus Torvalds 已提交
2059 2060 2061 2062
		generic_make_request(wbio);
	}

	if (atomic_dec_and_test(&r1_bio->remaining)) {
2063
		/* if we're here, all write(s) have completed, so clean up */
2064 2065 2066 2067 2068 2069 2070 2071
		int s = r1_bio->sectors;
		if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
		    test_bit(R1BIO_WriteError, &r1_bio->state))
			reschedule_retry(r1_bio);
		else {
			put_buf(r1_bio);
			md_done_sync(mddev, s, 1);
		}
L
Linus Torvalds 已提交
2072 2073 2074 2075 2076 2077 2078 2079
	}
}

/*
 * This is a kernel thread which:
 *
 *	1.	Retries failed read operations on working mirrors.
 *	2.	Updates the raid superblock when problems encounter.
2080
 *	3.	Performs writes following reads for array synchronising.
L
Linus Torvalds 已提交
2081 2082
 */

2083
static void fix_read_error(struct r1conf *conf, int read_disk,
2084 2085
			   sector_t sect, int sectors)
{
2086
	struct mddev *mddev = conf->mddev;
2087 2088 2089 2090 2091
	while(sectors) {
		int s = sectors;
		int d = read_disk;
		int success = 0;
		int start;
2092
		struct md_rdev *rdev;
2093 2094 2095 2096 2097 2098 2099 2100 2101 2102

		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....
			 */
2103 2104 2105
			sector_t first_bad;
			int bad_sectors;

2106 2107
			rdev = conf->mirrors[d].rdev;
			if (rdev &&
2108 2109 2110
			    (test_bit(In_sync, &rdev->flags) ||
			     (!test_bit(Faulty, &rdev->flags) &&
			      rdev->recovery_offset >= sect + s)) &&
2111 2112
			    is_badblock(rdev, sect, s,
					&first_bad, &bad_sectors) == 0 &&
2113 2114
			    sync_page_io(rdev, sect, s<<9,
					 conf->tmppage, READ, false))
2115 2116 2117
				success = 1;
			else {
				d++;
2118
				if (d == conf->raid_disks * 2)
2119 2120 2121 2122 2123
					d = 0;
			}
		} while (!success && d != read_disk);

		if (!success) {
2124
			/* Cannot read from anywhere - mark it bad */
2125
			struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2126 2127
			if (!rdev_set_badblocks(rdev, sect, s, 0))
				md_error(mddev, rdev);
2128 2129 2130 2131 2132 2133
			break;
		}
		/* write it back and re-read */
		start = d;
		while (d != read_disk) {
			if (d==0)
2134
				d = conf->raid_disks * 2;
2135 2136 2137
			d--;
			rdev = conf->mirrors[d].rdev;
			if (rdev &&
2138 2139 2140
			    test_bit(In_sync, &rdev->flags))
				r1_sync_page_io(rdev, sect, s,
						conf->tmppage, WRITE);
2141 2142 2143 2144 2145
		}
		d = start;
		while (d != read_disk) {
			char b[BDEVNAME_SIZE];
			if (d==0)
2146
				d = conf->raid_disks * 2;
2147 2148 2149 2150
			d--;
			rdev = conf->mirrors[d].rdev;
			if (rdev &&
			    test_bit(In_sync, &rdev->flags)) {
2151 2152
				if (r1_sync_page_io(rdev, sect, s,
						    conf->tmppage, READ)) {
2153 2154
					atomic_add(s, &rdev->corrected_errors);
					printk(KERN_INFO
2155
					       "md/raid1:%s: read error corrected "
2156 2157
					       "(%d sectors at %llu on %s)\n",
					       mdname(mddev), s,
2158 2159
					       (unsigned long long)(sect +
					           rdev->data_offset),
2160 2161 2162 2163 2164 2165 2166 2167 2168
					       bdevname(rdev->bdev, b));
				}
			}
		}
		sectors -= s;
		sect += s;
	}
}

2169
static int narrow_write_error(struct r1bio *r1_bio, int i)
2170
{
2171
	struct mddev *mddev = r1_bio->mddev;
2172
	struct r1conf *conf = mddev->private;
2173
	struct md_rdev *rdev = conf->mirrors[i].rdev;
2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206

	/* 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;

	while (sect_to_write) {
		struct bio *wbio;
		if (sectors > sect_to_write)
			sectors = sect_to_write;
		/* Write at 'sector' for 'sectors'*/

2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223
		if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
			unsigned vcnt = r1_bio->behind_page_count;
			struct bio_vec *vec = r1_bio->behind_bvecs;

			while (!vec->bv_page) {
				vec++;
				vcnt--;
			}

			wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
			memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));

			wbio->bi_vcnt = vcnt;
		} else {
			wbio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
		}

2224
		wbio->bi_rw = WRITE;
2225 2226
		wbio->bi_iter.bi_sector = r1_bio->sector;
		wbio->bi_iter.bi_size = r1_bio->sectors << 9;
2227

2228
		bio_trim(wbio, sector - r1_bio->sector, sectors);
2229
		wbio->bi_iter.bi_sector += rdev->data_offset;
2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244
		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;
}

2245
static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2246 2247 2248
{
	int m;
	int s = r1_bio->sectors;
2249
	for (m = 0; m < conf->raid_disks * 2 ; m++) {
2250
		struct md_rdev *rdev = conf->mirrors[m].rdev;
2251 2252 2253 2254 2255
		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)) {
2256
			rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267
		}
		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);
}

2268
static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2269 2270
{
	int m;
2271
	for (m = 0; m < conf->raid_disks * 2 ; m++)
2272
		if (r1_bio->bios[m] == IO_MADE_GOOD) {
2273
			struct md_rdev *rdev = conf->mirrors[m].rdev;
2274 2275
			rdev_clear_badblocks(rdev,
					     r1_bio->sector,
2276
					     r1_bio->sectors, 0);
2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296
			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);
}

2297
static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2298 2299 2300
{
	int disk;
	int max_sectors;
2301
	struct mddev *mddev = conf->mddev;
2302 2303
	struct bio *bio;
	char b[BDEVNAME_SIZE];
2304
	struct md_rdev *rdev;
2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315

	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) {
2316
		freeze_array(conf, 1);
2317 2318 2319 2320 2321
		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);
2322
	rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev);
2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342

	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);
2343 2344
		bio_trim(bio, r1_bio->sector - bio->bi_iter.bi_sector,
			 max_sectors);
2345 2346 2347 2348 2349 2350 2351 2352
		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));
2353
		bio->bi_iter.bi_sector = r1_bio->sector + rdev->data_offset;
2354 2355 2356 2357 2358 2359 2360 2361
		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
2362
					       - mbio->bi_iter.bi_sector);
2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375
			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;
2376
			r1_bio->sectors = bio_sectors(mbio) - sectors_handled;
2377 2378 2379
			r1_bio->state = 0;
			set_bit(R1BIO_ReadError, &r1_bio->state);
			r1_bio->mddev = mddev;
2380 2381
			r1_bio->sector = mbio->bi_iter.bi_sector +
				sectors_handled;
2382 2383 2384 2385 2386 2387 2388

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

2389
static void raid1d(struct md_thread *thread)
L
Linus Torvalds 已提交
2390
{
2391
	struct mddev *mddev = thread->mddev;
2392
	struct r1bio *r1_bio;
L
Linus Torvalds 已提交
2393
	unsigned long flags;
2394
	struct r1conf *conf = mddev->private;
L
Linus Torvalds 已提交
2395
	struct list_head *head = &conf->retry_list;
2396
	struct blk_plug plug;
L
Linus Torvalds 已提交
2397 2398

	md_check_recovery(mddev);
2399 2400

	blk_start_plug(&plug);
L
Linus Torvalds 已提交
2401
	for (;;) {
2402

2403
		flush_pending_writes(conf);
2404

2405 2406 2407
		spin_lock_irqsave(&conf->device_lock, flags);
		if (list_empty(head)) {
			spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
2408
			break;
2409
		}
2410
		r1_bio = list_entry(head->prev, struct r1bio, retry_list);
L
Linus Torvalds 已提交
2411
		list_del(head->prev);
2412
		conf->nr_queued--;
L
Linus Torvalds 已提交
2413 2414 2415
		spin_unlock_irqrestore(&conf->device_lock, flags);

		mddev = r1_bio->mddev;
2416
		conf = mddev->private;
2417
		if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2418
			if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2419 2420 2421
			    test_bit(R1BIO_WriteError, &r1_bio->state))
				handle_sync_write_finished(conf, r1_bio);
			else
2422
				sync_request_write(mddev, r1_bio);
2423
		} else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2424 2425 2426 2427 2428
			   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
2429 2430 2431 2432
			/* just a partial read to be scheduled from separate
			 * context
			 */
			generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2433

2434
		cond_resched();
2435 2436
		if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
			md_check_recovery(mddev);
L
Linus Torvalds 已提交
2437
	}
2438
	blk_finish_plug(&plug);
L
Linus Torvalds 已提交
2439 2440 2441
}


2442
static int init_resync(struct r1conf *conf)
L
Linus Torvalds 已提交
2443 2444 2445 2446
{
	int buffs;

	buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2447
	BUG_ON(conf->r1buf_pool);
L
Linus Torvalds 已提交
2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465
	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.
 */

2466
static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
L
Linus Torvalds 已提交
2467
{
2468
	struct r1conf *conf = mddev->private;
2469
	struct r1bio *r1_bio;
L
Linus Torvalds 已提交
2470 2471
	struct bio *bio;
	sector_t max_sector, nr_sectors;
2472
	int disk = -1;
L
Linus Torvalds 已提交
2473
	int i;
2474 2475
	int wonly = -1;
	int write_targets = 0, read_targets = 0;
2476
	sector_t sync_blocks;
2477
	int still_degraded = 0;
2478 2479
	int good_sectors = RESYNC_SECTORS;
	int min_bad = 0; /* number of sectors that are bad in all devices */
L
Linus Torvalds 已提交
2480 2481 2482

	if (!conf->r1buf_pool)
		if (init_resync(conf))
2483
			return 0;
L
Linus Torvalds 已提交
2484

2485
	max_sector = mddev->dev_sectors;
L
Linus Torvalds 已提交
2486
	if (sector_nr >= max_sector) {
2487 2488 2489 2490 2491
		/* 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
		 */
2492 2493
		if (mddev->curr_resync < max_sector) /* aborted */
			bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2494
						&sync_blocks, 1);
2495
		else /* completed sync */
2496
			conf->fullsync = 0;
2497 2498

		bitmap_close_sync(mddev->bitmap);
L
Linus Torvalds 已提交
2499 2500 2501 2502
		close_sync(conf);
		return 0;
	}

2503 2504
	if (mddev->bitmap == NULL &&
	    mddev->recovery_cp == MaxSector &&
2505
	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2506 2507 2508 2509
	    conf->fullsync == 0) {
		*skipped = 1;
		return max_sector - sector_nr;
	}
2510 2511 2512
	/* before building a request, check if we can skip these blocks..
	 * This call the bitmap_start_sync doesn't actually record anything
	 */
2513
	if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2514
	    !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2515 2516 2517 2518
		/* We can skip this block, and probably several more */
		*skipped = 1;
		return sync_blocks;
	}
L
Linus Torvalds 已提交
2519
	/*
2520 2521 2522
	 * 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
2523
	 */
2524
	if (!go_faster && conf->nr_waiting)
L
Linus Torvalds 已提交
2525
		msleep_interruptible(1000);
2526

2527
	bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2528
	r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2529 2530 2531
	raise_barrier(conf);

	conf->next_resync = sector_nr;
L
Linus Torvalds 已提交
2532

2533
	rcu_read_lock();
L
Linus Torvalds 已提交
2534
	/*
2535 2536 2537 2538 2539 2540
	 * 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
2541 2542 2543 2544
	 */

	r1_bio->mddev = mddev;
	r1_bio->sector = sector_nr;
2545
	r1_bio->state = 0;
L
Linus Torvalds 已提交
2546 2547
	set_bit(R1BIO_IsSync, &r1_bio->state);

2548
	for (i = 0; i < conf->raid_disks * 2; i++) {
2549
		struct md_rdev *rdev;
L
Linus Torvalds 已提交
2550
		bio = r1_bio->bios[i];
K
Kent Overstreet 已提交
2551
		bio_reset(bio);
L
Linus Torvalds 已提交
2552

2553 2554
		rdev = rcu_dereference(conf->mirrors[i].rdev);
		if (rdev == NULL ||
2555
		    test_bit(Faulty, &rdev->flags)) {
2556 2557
			if (i < conf->raid_disks)
				still_degraded = 1;
2558
		} else if (!test_bit(In_sync, &rdev->flags)) {
L
Linus Torvalds 已提交
2559 2560 2561
			bio->bi_rw = WRITE;
			bio->bi_end_io = end_sync_write;
			write_targets ++;
2562 2563
		} else {
			/* may need to read from here */
2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588
			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++;
2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600
			} else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
				test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
				!test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
				/*
				 * The device is suitable for reading (InSync),
				 * but has bad block(s) here. Let's try to correct them,
				 * if we are doing resync or repair. Otherwise, leave
				 * this device alone for this sync request.
				 */
				bio->bi_rw = WRITE;
				bio->bi_end_io = end_sync_write;
				write_targets++;
2601 2602
			}
		}
2603 2604
		if (bio->bi_end_io) {
			atomic_inc(&rdev->nr_pending);
2605
			bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
2606 2607 2608
			bio->bi_bdev = rdev->bdev;
			bio->bi_private = r1_bio;
		}
L
Linus Torvalds 已提交
2609
	}
2610 2611 2612 2613
	rcu_read_unlock();
	if (disk < 0)
		disk = wonly;
	r1_bio->read_disk = disk;
2614

2615 2616 2617 2618 2619
	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;
2620
		for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2621
			if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2622
				struct md_rdev *rdev = conf->mirrors[i].rdev;
2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649
				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;
	}

2650 2651 2652 2653 2654
	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
2655 2656 2657
		/* There is nowhere to write, so all non-sync
		 * drives must be failed - so we are finished
		 */
2658 2659 2660 2661
		sector_t rv;
		if (min_bad > 0)
			max_sector = sector_nr + min_bad;
		rv = max_sector - sector_nr;
2662
		*skipped = 1;
L
Linus Torvalds 已提交
2663 2664 2665 2666
		put_buf(r1_bio);
		return rv;
	}

2667 2668
	if (max_sector > mddev->resync_max)
		max_sector = mddev->resync_max; /* Don't do IO beyond here */
2669 2670
	if (max_sector > sector_nr + good_sectors)
		max_sector = sector_nr + good_sectors;
L
Linus Torvalds 已提交
2671
	nr_sectors = 0;
2672
	sync_blocks = 0;
L
Linus Torvalds 已提交
2673 2674 2675 2676 2677 2678 2679
	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;
2680 2681
		if (sync_blocks == 0) {
			if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2682 2683 2684
					       &sync_blocks, still_degraded) &&
			    !conf->fullsync &&
			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2685
				break;
2686
			BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2687
			if ((len >> 9) > sync_blocks)
2688
				len = sync_blocks<<9;
2689
		}
2690

2691
		for (i = 0 ; i < conf->raid_disks * 2; i++) {
L
Linus Torvalds 已提交
2692 2693
			bio = r1_bio->bios[i];
			if (bio->bi_end_io) {
2694
				page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
L
Linus Torvalds 已提交
2695 2696
				if (bio_add_page(bio, page, len, 0) == 0) {
					/* stop here */
2697
					bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
L
Linus Torvalds 已提交
2698 2699 2700
					while (i > 0) {
						i--;
						bio = r1_bio->bios[i];
2701 2702
						if (bio->bi_end_io==NULL)
							continue;
L
Linus Torvalds 已提交
2703 2704
						/* remove last page from this bio */
						bio->bi_vcnt--;
2705
						bio->bi_iter.bi_size -= len;
L
Linus Torvalds 已提交
2706 2707 2708 2709 2710 2711 2712 2713
						bio->bi_flags &= ~(1<< BIO_SEG_VALID);
					}
					goto bio_full;
				}
			}
		}
		nr_sectors += len>>9;
		sector_nr += len>>9;
2714
		sync_blocks -= (len>>9);
L
Linus Torvalds 已提交
2715 2716 2717 2718
	} while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
 bio_full:
	r1_bio->sectors = nr_sectors;

2719 2720 2721 2722 2723
	/* 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);
2724
		for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2725 2726
			bio = r1_bio->bios[i];
			if (bio->bi_end_io == end_sync_read) {
2727
				read_targets--;
2728
				md_sync_acct(bio->bi_bdev, nr_sectors);
2729 2730 2731 2732 2733 2734
				generic_make_request(bio);
			}
		}
	} else {
		atomic_set(&r1_bio->remaining, 1);
		bio = r1_bio->bios[r1_bio->read_disk];
2735
		md_sync_acct(bio->bi_bdev, nr_sectors);
2736
		generic_make_request(bio);
L
Linus Torvalds 已提交
2737

2738
	}
L
Linus Torvalds 已提交
2739 2740 2741
	return nr_sectors;
}

2742
static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2743 2744 2745 2746 2747 2748 2749
{
	if (sectors)
		return sectors;

	return mddev->dev_sectors;
}

2750
static struct r1conf *setup_conf(struct mddev *mddev)
L
Linus Torvalds 已提交
2751
{
2752
	struct r1conf *conf;
2753
	int i;
2754
	struct raid1_info *disk;
2755
	struct md_rdev *rdev;
2756
	int err = -ENOMEM;
L
Linus Torvalds 已提交
2757

2758
	conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
L
Linus Torvalds 已提交
2759
	if (!conf)
2760
		goto abort;
L
Linus Torvalds 已提交
2761

2762
	conf->mirrors = kzalloc(sizeof(struct raid1_info)
2763
				* mddev->raid_disks * 2,
L
Linus Torvalds 已提交
2764 2765
				 GFP_KERNEL);
	if (!conf->mirrors)
2766
		goto abort;
L
Linus Torvalds 已提交
2767

2768 2769
	conf->tmppage = alloc_page(GFP_KERNEL);
	if (!conf->tmppage)
2770
		goto abort;
2771

2772
	conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
L
Linus Torvalds 已提交
2773
	if (!conf->poolinfo)
2774
		goto abort;
2775
	conf->poolinfo->raid_disks = mddev->raid_disks * 2;
L
Linus Torvalds 已提交
2776 2777 2778 2779
	conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
					  r1bio_pool_free,
					  conf->poolinfo);
	if (!conf->r1bio_pool)
2780 2781
		goto abort;

2782
	conf->poolinfo->mddev = mddev;
L
Linus Torvalds 已提交
2783

2784
	err = -EINVAL;
2785
	spin_lock_init(&conf->device_lock);
2786
	rdev_for_each(rdev, mddev) {
2787
		struct request_queue *q;
2788
		int disk_idx = rdev->raid_disk;
L
Linus Torvalds 已提交
2789 2790 2791
		if (disk_idx >= mddev->raid_disks
		    || disk_idx < 0)
			continue;
2792
		if (test_bit(Replacement, &rdev->flags))
2793
			disk = conf->mirrors + mddev->raid_disks + disk_idx;
2794 2795
		else
			disk = conf->mirrors + disk_idx;
L
Linus Torvalds 已提交
2796

2797 2798
		if (disk->rdev)
			goto abort;
L
Linus Torvalds 已提交
2799
		disk->rdev = rdev;
2800 2801 2802
		q = bdev_get_queue(rdev->bdev);
		if (q->merge_bvec_fn)
			mddev->merge_check_needed = 1;
L
Linus Torvalds 已提交
2803 2804

		disk->head_position = 0;
2805
		disk->seq_start = MaxSector;
L
Linus Torvalds 已提交
2806 2807 2808 2809 2810 2811
	}
	conf->raid_disks = mddev->raid_disks;
	conf->mddev = mddev;
	INIT_LIST_HEAD(&conf->retry_list);

	spin_lock_init(&conf->resync_lock);
2812
	init_waitqueue_head(&conf->wait_barrier);
L
Linus Torvalds 已提交
2813

2814
	bio_list_init(&conf->pending_bio_list);
2815
	conf->pending_count = 0;
2816
	conf->recovery_disabled = mddev->recovery_disabled - 1;
2817

2818 2819 2820
	conf->start_next_window = MaxSector;
	conf->current_window_requests = conf->next_window_requests = 0;

2821
	err = -EIO;
2822
	for (i = 0; i < conf->raid_disks * 2; i++) {
L
Linus Torvalds 已提交
2823 2824 2825

		disk = conf->mirrors + i;

2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840
		if (i < conf->raid_disks &&
		    disk[conf->raid_disks].rdev) {
			/* This slot has a replacement. */
			if (!disk->rdev) {
				/* No original, just make the replacement
				 * a recovering spare
				 */
				disk->rdev =
					disk[conf->raid_disks].rdev;
				disk[conf->raid_disks].rdev = NULL;
			} else if (!test_bit(In_sync, &disk->rdev->flags))
				/* Original is not in_sync - bad */
				goto abort;
		}

2841 2842
		if (!disk->rdev ||
		    !test_bit(In_sync, &disk->rdev->flags)) {
L
Linus Torvalds 已提交
2843
			disk->head_position = 0;
2844 2845
			if (disk->rdev &&
			    (disk->rdev->saved_raid_disk < 0))
2846
				conf->fullsync = 1;
2847
		}
L
Linus Torvalds 已提交
2848
	}
2849 2850

	err = -ENOMEM;
2851
	conf->thread = md_register_thread(raid1d, mddev, "raid1");
2852 2853
	if (!conf->thread) {
		printk(KERN_ERR
2854
		       "md/raid1:%s: couldn't allocate thread\n",
2855 2856
		       mdname(mddev));
		goto abort;
2857
	}
L
Linus Torvalds 已提交
2858

2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872
	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);
}

2873
static int stop(struct mddev *mddev);
2874
static int run(struct mddev *mddev)
2875
{
2876
	struct r1conf *conf;
2877
	int i;
2878
	struct md_rdev *rdev;
2879
	int ret;
S
Shaohua Li 已提交
2880
	bool discard_supported = false;
2881 2882

	if (mddev->level != 1) {
2883
		printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2884 2885 2886 2887
		       mdname(mddev), mddev->level);
		return -EIO;
	}
	if (mddev->reshape_position != MaxSector) {
2888
		printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2889 2890 2891
		       mdname(mddev));
		return -EIO;
	}
L
Linus Torvalds 已提交
2892
	/*
2893 2894 2895
	 * 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
2896
	 */
2897 2898 2899 2900
	if (mddev->private == NULL)
		conf = setup_conf(mddev);
	else
		conf = mddev->private;
L
Linus Torvalds 已提交
2901

2902 2903
	if (IS_ERR(conf))
		return PTR_ERR(conf);
L
Linus Torvalds 已提交
2904

2905
	if (mddev->queue)
2906 2907
		blk_queue_max_write_same_sectors(mddev->queue, 0);

2908
	rdev_for_each(rdev, mddev) {
2909 2910
		if (!mddev->gendisk)
			continue;
2911 2912
		disk_stack_limits(mddev->gendisk, rdev->bdev,
				  rdev->data_offset << 9);
S
Shaohua Li 已提交
2913 2914
		if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
			discard_supported = true;
L
Linus Torvalds 已提交
2915
	}
2916

2917 2918 2919 2920 2921 2922 2923 2924 2925 2926
	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;

2927
	if (mddev->recovery_cp != MaxSector)
2928
		printk(KERN_NOTICE "md/raid1:%s: not clean"
2929 2930
		       " -- starting background reconstruction\n",
		       mdname(mddev));
L
Linus Torvalds 已提交
2931
	printk(KERN_INFO 
2932
		"md/raid1:%s: active with %d out of %d mirrors\n",
L
Linus Torvalds 已提交
2933 2934
		mdname(mddev), mddev->raid_disks - mddev->degraded, 
		mddev->raid_disks);
2935

L
Linus Torvalds 已提交
2936 2937 2938
	/*
	 * Ok, everything is just fine now
	 */
2939 2940 2941 2942
	mddev->thread = conf->thread;
	conf->thread = NULL;
	mddev->private = conf;

2943
	md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
L
Linus Torvalds 已提交
2944

2945 2946 2947
	if (mddev->queue) {
		mddev->queue->backing_dev_info.congested_fn = raid1_congested;
		mddev->queue->backing_dev_info.congested_data = mddev;
2948
		blk_queue_merge_bvec(mddev->queue, raid1_mergeable_bvec);
S
Shaohua Li 已提交
2949 2950 2951 2952 2953 2954 2955

		if (discard_supported)
			queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
						mddev->queue);
		else
			queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
						  mddev->queue);
2956
	}
2957 2958 2959 2960 2961

	ret =  md_integrity_register(mddev);
	if (ret)
		stop(mddev);
	return ret;
L
Linus Torvalds 已提交
2962 2963
}

2964
static int stop(struct mddev *mddev)
L
Linus Torvalds 已提交
2965
{
2966
	struct r1conf *conf = mddev->private;
2967 2968 2969
	struct bitmap *bitmap = mddev->bitmap;

	/* wait for behind writes to complete */
2970
	if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2971 2972
		printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
		       mdname(mddev));
2973
		/* need to kick something here to make sure I/O goes? */
2974 2975
		wait_event(bitmap->behind_wait,
			   atomic_read(&bitmap->behind_writes) == 0);
2976
	}
L
Linus Torvalds 已提交
2977

2978 2979
	freeze_array(conf, 0);
	unfreeze_array(conf);
2980

2981
	md_unregister_thread(&mddev->thread);
L
Linus Torvalds 已提交
2982 2983
	if (conf->r1bio_pool)
		mempool_destroy(conf->r1bio_pool);
2984
	kfree(conf->mirrors);
2985
	safe_put_page(conf->tmppage);
2986
	kfree(conf->poolinfo);
L
Linus Torvalds 已提交
2987 2988 2989 2990 2991
	kfree(conf);
	mddev->private = NULL;
	return 0;
}

2992
static int raid1_resize(struct mddev *mddev, sector_t sectors)
L
Linus Torvalds 已提交
2993 2994 2995 2996 2997 2998 2999 3000
{
	/* 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.
	 */
3001 3002 3003
	sector_t newsize = raid1_size(mddev, sectors, 0);
	if (mddev->external_size &&
	    mddev->array_sectors > newsize)
3004
		return -EINVAL;
3005 3006 3007 3008 3009 3010
	if (mddev->bitmap) {
		int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0);
		if (ret)
			return ret;
	}
	md_set_array_sectors(mddev, newsize);
3011
	set_capacity(mddev->gendisk, mddev->array_sectors);
3012
	revalidate_disk(mddev->gendisk);
3013
	if (sectors > mddev->dev_sectors &&
3014
	    mddev->recovery_cp > mddev->dev_sectors) {
3015
		mddev->recovery_cp = mddev->dev_sectors;
L
Linus Torvalds 已提交
3016 3017
		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
	}
3018
	mddev->dev_sectors = sectors;
3019
	mddev->resync_max_sectors = sectors;
L
Linus Torvalds 已提交
3020 3021 3022
	return 0;
}

3023
static int raid1_reshape(struct mddev *mddev)
L
Linus Torvalds 已提交
3024 3025 3026 3027 3028 3029 3030 3031
{
	/* 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.
3032 3033 3034
	 *
	 * At the same time, we "pack" the devices so that all the missing
	 * devices have the higher raid_disk numbers.
L
Linus Torvalds 已提交
3035 3036 3037
	 */
	mempool_t *newpool, *oldpool;
	struct pool_info *newpoolinfo;
3038
	struct raid1_info *newmirrors;
3039
	struct r1conf *conf = mddev->private;
3040
	int cnt, raid_disks;
3041
	unsigned long flags;
3042
	int d, d2, err;
L
Linus Torvalds 已提交
3043

3044
	/* Cannot change chunk_size, layout, or level */
3045
	if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
3046 3047
	    mddev->layout != mddev->new_layout ||
	    mddev->level != mddev->new_level) {
3048
		mddev->new_chunk_sectors = mddev->chunk_sectors;
3049 3050 3051 3052 3053
		mddev->new_layout = mddev->layout;
		mddev->new_level = mddev->level;
		return -EINVAL;
	}

3054 3055 3056
	err = md_allow_write(mddev);
	if (err)
		return err;
3057

3058 3059
	raid_disks = mddev->raid_disks + mddev->delta_disks;

3060 3061 3062 3063 3064 3065
	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
3066
			return -EBUSY;
3067
	}
L
Linus Torvalds 已提交
3068 3069 3070 3071 3072

	newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
	if (!newpoolinfo)
		return -ENOMEM;
	newpoolinfo->mddev = mddev;
3073
	newpoolinfo->raid_disks = raid_disks * 2;
L
Linus Torvalds 已提交
3074 3075 3076 3077 3078 3079 3080

	newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
				 r1bio_pool_free, newpoolinfo);
	if (!newpool) {
		kfree(newpoolinfo);
		return -ENOMEM;
	}
3081
	newmirrors = kzalloc(sizeof(struct raid1_info) * raid_disks * 2,
3082
			     GFP_KERNEL);
L
Linus Torvalds 已提交
3083 3084 3085 3086 3087 3088
	if (!newmirrors) {
		kfree(newpoolinfo);
		mempool_destroy(newpool);
		return -ENOMEM;
	}

3089
	freeze_array(conf, 0);
L
Linus Torvalds 已提交
3090 3091 3092 3093

	/* ok, everything is stopped */
	oldpool = conf->r1bio_pool;
	conf->r1bio_pool = newpool;
3094

3095
	for (d = d2 = 0; d < conf->raid_disks; d++) {
3096
		struct md_rdev *rdev = conf->mirrors[d].rdev;
3097
		if (rdev && rdev->raid_disk != d2) {
3098
			sysfs_unlink_rdev(mddev, rdev);
3099
			rdev->raid_disk = d2;
3100 3101
			sysfs_unlink_rdev(mddev, rdev);
			if (sysfs_link_rdev(mddev, rdev))
3102
				printk(KERN_WARNING
3103 3104
				       "md/raid1:%s: cannot register rd%d\n",
				       mdname(mddev), rdev->raid_disk);
3105
		}
3106 3107 3108
		if (rdev)
			newmirrors[d2++].rdev = rdev;
	}
L
Linus Torvalds 已提交
3109 3110 3111 3112 3113
	kfree(conf->mirrors);
	conf->mirrors = newmirrors;
	kfree(conf->poolinfo);
	conf->poolinfo = newpoolinfo;

3114
	spin_lock_irqsave(&conf->device_lock, flags);
L
Linus Torvalds 已提交
3115
	mddev->degraded += (raid_disks - conf->raid_disks);
3116
	spin_unlock_irqrestore(&conf->device_lock, flags);
L
Linus Torvalds 已提交
3117
	conf->raid_disks = mddev->raid_disks = raid_disks;
3118
	mddev->delta_disks = 0;
L
Linus Torvalds 已提交
3119

3120
	unfreeze_array(conf);
L
Linus Torvalds 已提交
3121 3122 3123 3124 3125 3126 3127 3128

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

	mempool_destroy(oldpool);
	return 0;
}

3129
static void raid1_quiesce(struct mddev *mddev, int state)
3130
{
3131
	struct r1conf *conf = mddev->private;
3132 3133

	switch(state) {
3134 3135 3136
	case 2: /* wake for suspend */
		wake_up(&conf->wait_barrier);
		break;
3137
	case 1:
3138
		freeze_array(conf, 0);
3139
		break;
3140
	case 0:
3141
		unfreeze_array(conf);
3142 3143 3144 3145
		break;
	}
}

3146
static void *raid1_takeover(struct mddev *mddev)
3147 3148 3149 3150 3151
{
	/* raid1 can take over:
	 *  raid5 with 2 devices, any layout or chunk size
	 */
	if (mddev->level == 5 && mddev->raid_disks == 2) {
3152
		struct r1conf *conf;
3153 3154 3155 3156 3157
		mddev->new_level = 1;
		mddev->new_layout = 0;
		mddev->new_chunk_sectors = 0;
		conf = setup_conf(mddev);
		if (!IS_ERR(conf))
3158 3159
			/* Array must appear to be quiesced */
			conf->array_frozen = 1;
3160 3161 3162 3163
		return conf;
	}
	return ERR_PTR(-EINVAL);
}
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Linus Torvalds 已提交
3164

3165
static struct md_personality raid1_personality =
L
Linus Torvalds 已提交
3166 3167
{
	.name		= "raid1",
3168
	.level		= 1,
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Linus Torvalds 已提交
3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179
	.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,
3180
	.size		= raid1_size,
3181
	.check_reshape	= raid1_reshape,
3182
	.quiesce	= raid1_quiesce,
3183
	.takeover	= raid1_takeover,
L
Linus Torvalds 已提交
3184 3185 3186 3187
};

static int __init raid_init(void)
{
3188
	return register_md_personality(&raid1_personality);
L
Linus Torvalds 已提交
3189 3190 3191 3192
}

static void raid_exit(void)
{
3193
	unregister_md_personality(&raid1_personality);
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Linus Torvalds 已提交
3194 3195 3196 3197 3198
}

module_init(raid_init);
module_exit(raid_exit);
MODULE_LICENSE("GPL");
3199
MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
L
Linus Torvalds 已提交
3200
MODULE_ALIAS("md-personality-3"); /* RAID1 */
3201
MODULE_ALIAS("md-raid1");
3202
MODULE_ALIAS("md-level-1");
3203 3204

module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);
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