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md/raid1: Refactor raid1_make_request
Refactor raid1_make_request to make read and write code in their own functions to clean up the code. Signed-off-by: Robert LeBlanc <robert@leblancnet.us> Signed-off-by: Shaohua Li <shli@fb.com>
This commit is contained in:
Robert LeBlanc
Shaohua Li
parent
0c744ea4f7
commit
3b046a97cb
@ -1066,17 +1066,107 @@ static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
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kfree(plug);
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}
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static void raid1_make_request(struct mddev *mddev, struct bio * bio)
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static void raid1_read_request(struct mddev *mddev, struct bio *bio,
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struct r1bio *r1_bio)
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{
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struct r1conf *conf = mddev->private;
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struct raid1_info *mirror;
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struct r1bio *r1_bio;
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struct bio *read_bio;
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struct bitmap *bitmap = mddev->bitmap;
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const int op = bio_op(bio);
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const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
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int sectors_handled;
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int max_sectors;
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int rdisk;
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wait_barrier(conf, bio);
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read_again:
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rdisk = read_balance(conf, r1_bio, &max_sectors);
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if (rdisk < 0) {
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/* couldn't find anywhere to read from */
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raid_end_bio_io(r1_bio);
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return;
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}
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mirror = conf->mirrors + rdisk;
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if (test_bit(WriteMostly, &mirror->rdev->flags) &&
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bitmap) {
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/*
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* Reading from a write-mostly device must take care not to
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* over-take any writes that are 'behind'
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*/
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raid1_log(mddev, "wait behind writes");
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wait_event(bitmap->behind_wait,
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atomic_read(&bitmap->behind_writes) == 0);
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}
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r1_bio->read_disk = rdisk;
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r1_bio->start_next_window = 0;
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read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
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bio_trim(read_bio, r1_bio->sector - bio->bi_iter.bi_sector,
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max_sectors);
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r1_bio->bios[rdisk] = read_bio;
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read_bio->bi_iter.bi_sector = r1_bio->sector +
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mirror->rdev->data_offset;
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read_bio->bi_bdev = mirror->rdev->bdev;
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read_bio->bi_end_io = raid1_end_read_request;
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bio_set_op_attrs(read_bio, op, do_sync);
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if (test_bit(FailFast, &mirror->rdev->flags) &&
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test_bit(R1BIO_FailFast, &r1_bio->state))
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read_bio->bi_opf |= MD_FAILFAST;
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read_bio->bi_private = r1_bio;
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if (mddev->gendisk)
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trace_block_bio_remap(bdev_get_queue(read_bio->bi_bdev),
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read_bio, disk_devt(mddev->gendisk),
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r1_bio->sector);
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if (max_sectors < r1_bio->sectors) {
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/*
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* could not read all from this device, so we will need another
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* r1_bio.
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*/
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sectors_handled = (r1_bio->sector + max_sectors
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- bio->bi_iter.bi_sector);
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r1_bio->sectors = max_sectors;
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spin_lock_irq(&conf->device_lock);
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if (bio->bi_phys_segments == 0)
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bio->bi_phys_segments = 2;
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else
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bio->bi_phys_segments++;
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spin_unlock_irq(&conf->device_lock);
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/*
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* Cannot call generic_make_request directly as that will be
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* queued in __make_request and subsequent mempool_alloc might
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* block waiting for it. So hand bio over to raid1d.
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*/
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reschedule_retry(r1_bio);
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r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
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r1_bio->master_bio = bio;
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r1_bio->sectors = bio_sectors(bio) - sectors_handled;
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r1_bio->state = 0;
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r1_bio->mddev = mddev;
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r1_bio->sector = bio->bi_iter.bi_sector + sectors_handled;
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goto read_again;
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} else
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generic_make_request(read_bio);
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}
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static void raid1_write_request(struct mddev *mddev, struct bio *bio,
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struct r1bio *r1_bio)
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{
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struct r1conf *conf = mddev->private;
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int i, disks;
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struct bitmap *bitmap;
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struct bitmap *bitmap = mddev->bitmap;
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unsigned long flags;
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const int op = bio_op(bio);
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const int rw = bio_data_dir(bio);
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const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
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const unsigned long do_flush_fua = (bio->bi_opf &
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(REQ_PREFLUSH | REQ_FUA));
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@ -1096,15 +1186,15 @@ static void raid1_make_request(struct mddev *mddev, struct bio * bio)
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md_write_start(mddev, bio); /* wait on superblock update early */
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if (bio_data_dir(bio) == WRITE &&
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((bio_end_sector(bio) > mddev->suspend_lo &&
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if ((bio_end_sector(bio) > mddev->suspend_lo &&
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bio->bi_iter.bi_sector < mddev->suspend_hi) ||
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(mddev_is_clustered(mddev) &&
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md_cluster_ops->area_resyncing(mddev, WRITE,
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bio->bi_iter.bi_sector, bio_end_sector(bio))))) {
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/* As the suspend_* range is controlled by
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* userspace, we want an interruptible
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* wait.
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bio->bi_iter.bi_sector, bio_end_sector(bio)))) {
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/*
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* As the suspend_* range is controlled by userspace, we want
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* an interruptible wait.
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*/
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DEFINE_WAIT(w);
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for (;;) {
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@ -1115,128 +1205,15 @@ static void raid1_make_request(struct mddev *mddev, struct bio * bio)
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bio->bi_iter.bi_sector >= mddev->suspend_hi ||
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(mddev_is_clustered(mddev) &&
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!md_cluster_ops->area_resyncing(mddev, WRITE,
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bio->bi_iter.bi_sector, bio_end_sector(bio))))
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bio->bi_iter.bi_sector,
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bio_end_sector(bio))))
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break;
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schedule();
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}
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finish_wait(&conf->wait_barrier, &w);
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}
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start_next_window = wait_barrier(conf, bio);
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bitmap = mddev->bitmap;
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/*
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* make_request() can abort the operation when read-ahead is being
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* used and no empty request is available.
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*
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*/
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r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
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r1_bio->master_bio = bio;
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r1_bio->sectors = bio_sectors(bio);
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r1_bio->state = 0;
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r1_bio->mddev = mddev;
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r1_bio->sector = bio->bi_iter.bi_sector;
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/* We might need to issue multiple reads to different
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* devices if there are bad blocks around, so we keep
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* track of the number of reads in bio->bi_phys_segments.
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* If this is 0, there is only one r1_bio and no locking
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* will be needed when requests complete. If it is
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* non-zero, then it is the number of not-completed requests.
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*/
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bio->bi_phys_segments = 0;
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bio_clear_flag(bio, BIO_SEG_VALID);
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if (rw == READ) {
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/*
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* read balancing logic:
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*/
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int rdisk;
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read_again:
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rdisk = read_balance(conf, r1_bio, &max_sectors);
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if (rdisk < 0) {
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/* couldn't find anywhere to read from */
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raid_end_bio_io(r1_bio);
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return;
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}
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mirror = conf->mirrors + rdisk;
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if (test_bit(WriteMostly, &mirror->rdev->flags) &&
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bitmap) {
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/* Reading from a write-mostly device must
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* take care not to over-take any writes
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* that are 'behind'
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*/
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raid1_log(mddev, "wait behind writes");
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wait_event(bitmap->behind_wait,
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atomic_read(&bitmap->behind_writes) == 0);
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}
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r1_bio->read_disk = rdisk;
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r1_bio->start_next_window = 0;
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read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
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bio_trim(read_bio, r1_bio->sector - bio->bi_iter.bi_sector,
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max_sectors);
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r1_bio->bios[rdisk] = read_bio;
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read_bio->bi_iter.bi_sector = r1_bio->sector +
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mirror->rdev->data_offset;
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read_bio->bi_bdev = mirror->rdev->bdev;
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read_bio->bi_end_io = raid1_end_read_request;
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bio_set_op_attrs(read_bio, op, do_sync);
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if (test_bit(FailFast, &mirror->rdev->flags) &&
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test_bit(R1BIO_FailFast, &r1_bio->state))
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read_bio->bi_opf |= MD_FAILFAST;
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read_bio->bi_private = r1_bio;
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if (mddev->gendisk)
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trace_block_bio_remap(bdev_get_queue(read_bio->bi_bdev),
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read_bio, disk_devt(mddev->gendisk),
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r1_bio->sector);
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if (max_sectors < r1_bio->sectors) {
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/* could not read all from this device, so we will
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* need another r1_bio.
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*/
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sectors_handled = (r1_bio->sector + max_sectors
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- bio->bi_iter.bi_sector);
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r1_bio->sectors = max_sectors;
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spin_lock_irq(&conf->device_lock);
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if (bio->bi_phys_segments == 0)
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bio->bi_phys_segments = 2;
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else
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bio->bi_phys_segments++;
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spin_unlock_irq(&conf->device_lock);
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/* Cannot call generic_make_request directly
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* as that will be queued in __make_request
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* and subsequent mempool_alloc might block waiting
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* for it. So hand bio over to raid1d.
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*/
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reschedule_retry(r1_bio);
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r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
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r1_bio->master_bio = bio;
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r1_bio->sectors = bio_sectors(bio) - sectors_handled;
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r1_bio->state = 0;
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r1_bio->mddev = mddev;
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r1_bio->sector = bio->bi_iter.bi_sector +
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sectors_handled;
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goto read_again;
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} else
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generic_make_request(read_bio);
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return;
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}
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/*
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* WRITE:
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*/
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if (conf->pending_count >= max_queued_requests) {
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md_wakeup_thread(mddev->thread);
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raid1_log(mddev, "wait queued");
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@ -1280,8 +1257,7 @@ read_again:
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int bad_sectors;
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int is_bad;
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is_bad = is_badblock(rdev, r1_bio->sector,
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max_sectors,
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is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
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&first_bad, &bad_sectors);
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if (is_bad < 0) {
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/* mustn't write here until the bad block is
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@ -1370,7 +1346,8 @@ read_again:
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continue;
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mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
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bio_trim(mbio, r1_bio->sector - bio->bi_iter.bi_sector, max_sectors);
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bio_trim(mbio, r1_bio->sector - bio->bi_iter.bi_sector,
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max_sectors);
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if (first_clone) {
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/* do behind I/O ?
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@ -1464,6 +1441,40 @@ read_again:
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wake_up(&conf->wait_barrier);
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}
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static void raid1_make_request(struct mddev *mddev, struct bio *bio)
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{
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struct r1conf *conf = mddev->private;
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struct r1bio *r1_bio;
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/*
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* make_request() can abort the operation when read-ahead is being
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* used and no empty request is available.
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*
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*/
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r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
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r1_bio->master_bio = bio;
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r1_bio->sectors = bio_sectors(bio);
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r1_bio->state = 0;
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r1_bio->mddev = mddev;
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r1_bio->sector = bio->bi_iter.bi_sector;
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/*
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* We might need to issue multiple reads to different devices if there
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* are bad blocks around, so we keep track of the number of reads in
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* bio->bi_phys_segments. If this is 0, there is only one r1_bio and
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* no locking will be needed when requests complete. If it is
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* non-zero, then it is the number of not-completed requests.
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*/
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bio->bi_phys_segments = 0;
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bio_clear_flag(bio, BIO_SEG_VALID);
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if (bio_data_dir(bio) == READ)
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raid1_read_request(mddev, bio, r1_bio);
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else
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raid1_write_request(mddev, bio, r1_bio);
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}
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static void raid1_status(struct seq_file *seq, struct mddev *mddev)
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{
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struct r1conf *conf = mddev->private;
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