Commit a68e5870 authored by NeilBrown's avatar NeilBrown
Browse files

md/raid1: split out two sub-functions from sync_request_write 



sync_request_write is too big and too deep.
So split out two self-contains bits of functionality into separate
function.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 6f8d0c77

drivers/md/raid1.c

+192 −173
Original line number Diff line number Diff line
@@ -1181,101 +1181,9 @@ static void end_sync_write(struct bio *bio, int error) 
	}

}



static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)

static int fix_sync_read_error(r1bio_t *r1_bio)

{

	conf_t *conf = mddev->private;

	int i;

	int disks = conf->raid_disks;

	struct bio *bio, *wbio;



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





	if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {

		/* 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

		 */

		int primary;

		if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {

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

				if (r1_bio->bios[i]->bi_end_io == end_sync_read)

					md_error(mddev, conf->mirrors[i].rdev);



			md_done_sync(mddev, r1_bio->sectors, 1);

			put_buf(r1_bio);

			return;

		}

		for (primary=0; primary<mddev->raid_disks; primary++)

			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;

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

			if (r1_bio->bios[i]->bi_end_io == end_sync_read) {

				int j;

				int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);

				struct bio *pbio = r1_bio->bios[primary];

				struct bio *sbio = r1_bio->bios[i];



				if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {

					for (j = vcnt; j-- ; ) {

						struct page *p, *s;

						p = pbio->bi_io_vec[j].bv_page;

						s = sbio->bi_io_vec[j].bv_page;

						if (memcmp(page_address(p),

							   page_address(s),

							   PAGE_SIZE))

							break;

					}

				} else

					j = 0;

				if (j >= 0)

					mddev->resync_mismatches += r1_bio->sectors;

				if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)

					      && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {

					sbio->bi_end_io = NULL;

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

				} else {

					/* fixup the bio for reuse */

					int size;

					sbio->bi_vcnt = vcnt;

					sbio->bi_size = r1_bio->sectors << 9;

					sbio->bi_idx = 0;

					sbio->bi_phys_segments = 0;

					sbio->bi_flags &= ~(BIO_POOL_MASK - 1);

					sbio->bi_flags |= 1 << BIO_UPTODATE;

					sbio->bi_next = NULL;

					sbio->bi_sector = r1_bio->sector +

						conf->mirrors[i].rdev->data_offset;

					sbio->bi_bdev = conf->mirrors[i].rdev->bdev;

					size = sbio->bi_size;

					for (j = 0; j < vcnt ; j++) {

						struct bio_vec *bi;

						bi = &sbio->bi_io_vec[j];

						bi->bv_offset = 0;

						if (size > PAGE_SIZE)

							bi->bv_len = PAGE_SIZE;

						else

							bi->bv_len = size;

						size -= PAGE_SIZE;

						memcpy(page_address(bi->bv_page),

						       page_address(pbio->bi_io_vec[j].bv_page),

						       PAGE_SIZE);

					}



				}

			}

	}

	if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {

		/* ouch - failed to read all of that.

		 * Try some synchronous reads of other devices to get

	/* 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.
@@ -1283,6 +1191,9 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio) 
	 * active sync request, there is no normal IO, and

	 * no overlapping syncs.

	 */

	mddev_t *mddev = r1_bio->mddev;

	conf_t *conf = mddev->private;

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

	sector_t sect = r1_bio->sector;

	int sectors = r1_bio->sectors;

	int idx = 0;
@@ -1361,14 +1272,122 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio) 
			       (unsigned long long)r1_bio->sector);

			md_done_sync(mddev, r1_bio->sectors, 0);

			put_buf(r1_bio);

				return;

			return 0;

		}

		sectors -= s;

		sect += s;

		idx ++;

	}

	return 1;

}



static int process_checks(r1bio_t *r1_bio)

{

	/* 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

	 */

	mddev_t *mddev = r1_bio->mddev;

	conf_t *conf = mddev->private;

	int primary;

	int i;



	if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {

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

			if (r1_bio->bios[i]->bi_end_io == end_sync_read)

				md_error(mddev, conf->mirrors[i].rdev);



		md_done_sync(mddev, r1_bio->sectors, 1);

		put_buf(r1_bio);

		return -1;

	}

	for (primary=0; primary<mddev->raid_disks; primary++)

		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;

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

		if (r1_bio->bios[i]->bi_end_io == end_sync_read) {

			int j;

			int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);

			struct bio *pbio = r1_bio->bios[primary];

			struct bio *sbio = r1_bio->bios[i];



			if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {

				for (j = vcnt; j-- ; ) {

					struct page *p, *s;

					p = pbio->bi_io_vec[j].bv_page;

					s = sbio->bi_io_vec[j].bv_page;

					if (memcmp(page_address(p),

						   page_address(s),

						   PAGE_SIZE))

						break;

				}

			} else

				j = 0;

			if (j >= 0)

				mddev->resync_mismatches += r1_bio->sectors;

			if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)

				      && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {

				sbio->bi_end_io = NULL;

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

			} else {

				/* fixup the bio for reuse */

				int size;

				sbio->bi_vcnt = vcnt;

				sbio->bi_size = r1_bio->sectors << 9;

				sbio->bi_idx = 0;

				sbio->bi_phys_segments = 0;

				sbio->bi_flags &= ~(BIO_POOL_MASK - 1);

				sbio->bi_flags |= 1 << BIO_UPTODATE;

				sbio->bi_next = NULL;

				sbio->bi_sector = r1_bio->sector +

					conf->mirrors[i].rdev->data_offset;

				sbio->bi_bdev = conf->mirrors[i].rdev->bdev;

				size = sbio->bi_size;

				for (j = 0; j < vcnt ; j++) {

					struct bio_vec *bi;

					bi = &sbio->bi_io_vec[j];

					bi->bv_offset = 0;

					if (size > PAGE_SIZE)

						bi->bv_len = PAGE_SIZE;

					else

						bi->bv_len = size;

					size -= PAGE_SIZE;

					memcpy(page_address(bi->bv_page),

					       page_address(pbio->bi_io_vec[j].bv_page),

					       PAGE_SIZE);

				}



			}

		}

	return 0;

}



static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)

{

	conf_t *conf = mddev->private;

	int i;

	int disks = conf->raid_disks;

	struct bio *bio, *wbio;



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





	if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))

		if (process_checks(r1_bio) < 0)

			return;



	if (!test_bit(R1BIO_Uptodate, &r1_bio->state))

		/* ouch - failed to read all of that. */

		if (!fix_sync_read_error(r1_bio))

			return;

	/*

	 * schedule writes

	 */