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[PATCH] md: raid1 support for bitmap intent logging
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Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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NeilBrown authored and Linus Torvalds committed Jun 22, 2005
1 parent aa3163f commit 191ea9b
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Showing 2 changed files with 168 additions and 30 deletions.
182 changes: 154 additions & 28 deletions drivers/md/raid1.c
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,15 @@
* Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
* Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
*
* 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
*
* 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)
Expand All @@ -22,7 +31,16 @@
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "dm-bio-list.h"
#include <linux/raid/raid1.h>
#include <linux/raid/bitmap.h>

#define DEBUG 0
#if DEBUG
#define PRINTK(x...) printk(x)
#else
#define PRINTK(x...)
#endif

/*
* Number of guaranteed r1bios in case of extreme VM load:
Expand Down Expand Up @@ -287,9 +305,11 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
/*
* this branch is our 'one mirror IO has finished' event handler:
*/
if (!uptodate)
if (!uptodate) {
md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
else
/* an I/O failed, we can't clear the bitmap */
set_bit(R1BIO_Degraded, &r1_bio->state);
} else
/*
* Set R1BIO_Uptodate in our master bio, so that
* we will return a good error code for to the higher
Expand All @@ -309,6 +329,10 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
* already.
*/
if (atomic_dec_and_test(&r1_bio->remaining)) {
/* 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));
md_write_end(r1_bio->mddev);
raid_end_bio_io(r1_bio);
}
Expand Down Expand Up @@ -458,7 +482,10 @@ static void unplug_slaves(mddev_t *mddev)

static void raid1_unplug(request_queue_t *q)
{
unplug_slaves(q->queuedata);
mddev_t *mddev = q->queuedata;

unplug_slaves(mddev);
md_wakeup_thread(mddev->thread);
}

static int raid1_issue_flush(request_queue_t *q, struct gendisk *disk,
Expand Down Expand Up @@ -501,16 +528,16 @@ static void device_barrier(conf_t *conf, sector_t sect)
{
spin_lock_irq(&conf->resync_lock);
wait_event_lock_irq(conf->wait_idle, !waitqueue_active(&conf->wait_resume),
conf->resync_lock, unplug_slaves(conf->mddev));
conf->resync_lock, raid1_unplug(conf->mddev->queue));

if (!conf->barrier++) {
wait_event_lock_irq(conf->wait_idle, !conf->nr_pending,
conf->resync_lock, unplug_slaves(conf->mddev));
conf->resync_lock, raid1_unplug(conf->mddev->queue));
if (conf->nr_pending)
BUG();
}
wait_event_lock_irq(conf->wait_resume, conf->barrier < RESYNC_DEPTH,
conf->resync_lock, unplug_slaves(conf->mddev));
conf->resync_lock, raid1_unplug(conf->mddev->queue));
conf->next_resync = sect;
spin_unlock_irq(&conf->resync_lock);
}
Expand All @@ -522,8 +549,12 @@ static int make_request(request_queue_t *q, struct bio * bio)
mirror_info_t *mirror;
r1bio_t *r1_bio;
struct bio *read_bio;
int i, disks;
int i, targets = 0, disks;
mdk_rdev_t *rdev;
struct bitmap *bitmap = mddev->bitmap;
unsigned long flags;
struct bio_list bl;


/*
* Register the new request and wait if the reconstruction
Expand Down Expand Up @@ -554,7 +585,7 @@ static int make_request(request_queue_t *q, struct bio * bio)

r1_bio->master_bio = bio;
r1_bio->sectors = bio->bi_size >> 9;

r1_bio->state = 0;
r1_bio->mddev = mddev;
r1_bio->sector = bio->bi_sector;

Expand Down Expand Up @@ -597,6 +628,13 @@ static int make_request(request_queue_t *q, struct bio * bio)
* bios[x] to bio
*/
disks = conf->raid_disks;
#if 0
{ static int first=1;
if (first) printk("First Write sector %llu disks %d\n",
(unsigned long long)r1_bio->sector, disks);
first = 0;
}
#endif
rcu_read_lock();
for (i = 0; i < disks; i++) {
if ((rdev=conf->mirrors[i].rdev) != NULL &&
Expand All @@ -607,13 +645,21 @@ static int make_request(request_queue_t *q, struct bio * bio)
r1_bio->bios[i] = NULL;
} else
r1_bio->bios[i] = bio;
targets++;
} else
r1_bio->bios[i] = NULL;
}
rcu_read_unlock();

atomic_set(&r1_bio->remaining, 1);
if (targets < conf->raid_disks) {
/* array is degraded, we will not clear the bitmap
* on I/O completion (see raid1_end_write_request) */
set_bit(R1BIO_Degraded, &r1_bio->state);
}

atomic_set(&r1_bio->remaining, 0);

bio_list_init(&bl);
for (i = 0; i < disks; i++) {
struct bio *mbio;
if (!r1_bio->bios[i])
Expand All @@ -629,14 +675,23 @@ static int make_request(request_queue_t *q, struct bio * bio)
mbio->bi_private = r1_bio;

atomic_inc(&r1_bio->remaining);
generic_make_request(mbio);
}

if (atomic_dec_and_test(&r1_bio->remaining)) {
md_write_end(mddev);
raid_end_bio_io(r1_bio);
bio_list_add(&bl, mbio);
}

bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors);
spin_lock_irqsave(&conf->device_lock, flags);
bio_list_merge(&conf->pending_bio_list, &bl);
bio_list_init(&bl);

blk_plug_device(mddev->queue);
spin_unlock_irqrestore(&conf->device_lock, flags);

#if 0
while ((bio = bio_list_pop(&bl)) != NULL)
generic_make_request(bio);
#endif

return 0;
}

Expand Down Expand Up @@ -716,7 +771,7 @@ static void close_sync(conf_t *conf)
{
spin_lock_irq(&conf->resync_lock);
wait_event_lock_irq(conf->wait_resume, !conf->barrier,
conf->resync_lock, unplug_slaves(conf->mddev));
conf->resync_lock, raid1_unplug(conf->mddev->queue));
spin_unlock_irq(&conf->resync_lock);

if (conf->barrier) BUG();
Expand Down Expand Up @@ -830,10 +885,11 @@ static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
* or re-read if the read failed.
* We don't do much here, just schedule handling by raid1d
*/
if (!uptodate)
if (!uptodate) {
md_error(r1_bio->mddev,
conf->mirrors[r1_bio->read_disk].rdev);
else
set_bit(R1BIO_Degraded, &r1_bio->state);
} else
set_bit(R1BIO_Uptodate, &r1_bio->state);
rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev);
reschedule_retry(r1_bio);
Expand All @@ -857,8 +913,10 @@ static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
mirror = i;
break;
}
if (!uptodate)
if (!uptodate) {
md_error(mddev, conf->mirrors[mirror].rdev);
set_bit(R1BIO_Degraded, &r1_bio->state);
}
update_head_pos(mirror, r1_bio);

if (atomic_dec_and_test(&r1_bio->remaining)) {
Expand All @@ -878,6 +936,9 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)

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

/*
if (r1_bio->sector == 0) printk("First sync write startss\n");
*/
/*
* schedule writes
*/
Expand Down Expand Up @@ -905,10 +966,12 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
atomic_inc(&conf->mirrors[i].rdev->nr_pending);
atomic_inc(&r1_bio->remaining);
md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);

generic_make_request(wbio);
}

if (atomic_dec_and_test(&r1_bio->remaining)) {
/* if we're here, all write(s) have completed, so clean up */
md_done_sync(mddev, r1_bio->sectors, 1);
put_buf(r1_bio);
}
Expand Down Expand Up @@ -937,6 +1000,26 @@ static void raid1d(mddev_t *mddev)
for (;;) {
char b[BDEVNAME_SIZE];
spin_lock_irqsave(&conf->device_lock, flags);

if (conf->pending_bio_list.head) {
bio = bio_list_get(&conf->pending_bio_list);
blk_remove_plug(mddev->queue);
spin_unlock_irqrestore(&conf->device_lock, flags);
/* flush any pending bitmap writes to disk before proceeding w/ I/O */
if (bitmap_unplug(mddev->bitmap) != 0)
printk("%s: bitmap file write failed!\n", mdname(mddev));

while (bio) { /* submit pending writes */
struct bio *next = bio->bi_next;
bio->bi_next = NULL;
generic_make_request(bio);
bio = next;
}
unplug = 1;

continue;
}

if (list_empty(head))
break;
r1_bio = list_entry(head->prev, r1bio_t, retry_list);
Expand Down Expand Up @@ -1020,17 +1103,43 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
int disk;
int i;
int write_targets = 0;
int sync_blocks;

if (!conf->r1buf_pool)
{
/*
printk("sync start - bitmap %p\n", mddev->bitmap);
*/
if (init_resync(conf))
return 0;
}

max_sector = mddev->size << 1;
if (sector_nr >= max_sector) {
/* 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
*/
if (!conf->fullsync) {
if (mddev->curr_resync < max_sector)
bitmap_end_sync(mddev->bitmap,
mddev->curr_resync,
&sync_blocks, 1);
bitmap_close_sync(mddev->bitmap);
}
if (mddev->curr_resync >= max_sector)
conf->fullsync = 0;
close_sync(conf);
return 0;
}

if (!conf->fullsync &&
!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks)) {
/* We can skip this block, and probably several more */
*skipped = 1;
return sync_blocks;
}
/*
* If there is non-resync activity waiting for us then
* put in a delay to throttle resync.
Expand Down Expand Up @@ -1069,6 +1178,7 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i

r1_bio->mddev = mddev;
r1_bio->sector = sector_nr;
r1_bio->state = 0;
set_bit(R1BIO_IsSync, &r1_bio->state);
r1_bio->read_disk = disk;

Expand Down Expand Up @@ -1103,6 +1213,11 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
bio->bi_bdev = conf->mirrors[i].rdev->bdev;
bio->bi_private = r1_bio;
}

if (write_targets + 1 < conf->raid_disks)
/* array degraded, can't clear bitmap */
set_bit(R1BIO_Degraded, &r1_bio->state);

if (write_targets == 0) {
/* There is nowhere to write, so all non-sync
* drives must be failed - so we are finished
Expand All @@ -1122,6 +1237,14 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
len = (max_sector - sector_nr) << 9;
if (len == 0)
break;
if (!conf->fullsync && sync_blocks == 0)
if (!bitmap_start_sync(mddev->bitmap,
sector_nr, &sync_blocks))
break;
if (sync_blocks < (PAGE_SIZE>>9))
BUG();
if (len > (sync_blocks<<9)) len = sync_blocks<<9;

for (i=0 ; i < conf->raid_disks; i++) {
bio = r1_bio->bios[i];
if (bio->bi_end_io) {
Expand All @@ -1144,6 +1267,7 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
}
nr_sectors += len>>9;
sector_nr += len>>9;
sync_blocks -= (len>>9);
} while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
bio_full:
bio = r1_bio->bios[disk];
Expand Down Expand Up @@ -1232,6 +1356,9 @@ static int run(mddev_t *mddev)
init_waitqueue_head(&conf->wait_idle);
init_waitqueue_head(&conf->wait_resume);

bio_list_init(&conf->pending_bio_list);
bio_list_init(&conf->flushing_bio_list);

if (!conf->working_disks) {
printk(KERN_ERR "raid1: no operational mirrors for %s\n",
mdname(mddev));
Expand Down Expand Up @@ -1260,16 +1387,15 @@ static int run(mddev_t *mddev)
conf->last_used = j;



{
mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
if (!mddev->thread) {
printk(KERN_ERR
"raid1: couldn't allocate thread for %s\n",
mdname(mddev));
goto out_free_conf;
}
mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
if (!mddev->thread) {
printk(KERN_ERR
"raid1: couldn't allocate thread for %s\n",
mdname(mddev));
goto out_free_conf;
}
if (mddev->bitmap) mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ;

printk(KERN_INFO
"raid1: raid set %s active with %d out of %d mirrors\n",
mdname(mddev), mddev->raid_disks - mddev->degraded,
Expand Down Expand Up @@ -1394,7 +1520,7 @@ static int raid1_reshape(mddev_t *mddev, int raid_disks)
spin_lock_irq(&conf->resync_lock);
conf->barrier++;
wait_event_lock_irq(conf->wait_idle, !conf->nr_pending,
conf->resync_lock, unplug_slaves(mddev));
conf->resync_lock, raid1_unplug(mddev->queue));
spin_unlock_irq(&conf->resync_lock);

/* ok, everything is stopped */
Expand Down
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