Commit 73c0f228 authored by Liu Bo's avatar Liu Bo Committed by David Sterba
Browse files

Btrfs: handle operations for device replace separately 



Since this part is mostly independent, this moves it to a separate
function.

Reviewed-by: default avatarQu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 5ab56090

fs/btrfs/volumes.c

+98 −81
Original line number Diff line number Diff line
@@ -5532,6 +5532,100 @@ static int get_extra_mirror_from_replace(struct btrfs_fs_info *fs_info, 
	return ret;

}



static void handle_ops_on_dev_replace(enum btrfs_map_op op,

				      struct btrfs_bio **bbio_ret,

				      struct btrfs_dev_replace *dev_replace,

				      int *num_stripes_ret, int *max_errors_ret)

{

	struct btrfs_bio *bbio = *bbio_ret;

	u64 srcdev_devid = dev_replace->srcdev->devid;

	int tgtdev_indexes = 0;

	int num_stripes = *num_stripes_ret;

	int max_errors = *max_errors_ret;

	int i;



	if (op == BTRFS_MAP_WRITE) {

		int index_where_to_add;



		/*

		 * duplicate the write operations while the dev replace

		 * procedure is running. Since the copying of the old disk to

		 * the new disk takes place at run time while the filesystem is

		 * mounted writable, the regular write operations to the old

		 * disk have to be duplicated to go to the new disk as well.

		 *

		 * Note that device->missing is handled by the caller, and that

		 * the write to the old disk is already set up in the stripes

		 * array.

		 */

		index_where_to_add = num_stripes;

		for (i = 0; i < num_stripes; i++) {

			if (bbio->stripes[i].dev->devid == srcdev_devid) {

				/* write to new disk, too */

				struct btrfs_bio_stripe *new =

					bbio->stripes + index_where_to_add;

				struct btrfs_bio_stripe *old =

					bbio->stripes + i;



				new->physical = old->physical;

				new->length = old->length;

				new->dev = dev_replace->tgtdev;

				bbio->tgtdev_map[i] = index_where_to_add;

				index_where_to_add++;

				max_errors++;

				tgtdev_indexes++;

			}

		}

		num_stripes = index_where_to_add;

	} else if (op == BTRFS_MAP_GET_READ_MIRRORS) {

		int index_srcdev = 0;

		int found = 0;

		u64 physical_of_found = 0;



		/*

		 * During the dev-replace procedure, the target drive can also

		 * be used to read data in case it is needed to repair a corrupt

		 * block elsewhere. This is possible if the requested area is

		 * left of the left cursor. In this area, the target drive is a

		 * full copy of the source drive.

		 */

		for (i = 0; i < num_stripes; i++) {

			if (bbio->stripes[i].dev->devid == srcdev_devid) {

				/*

				 * In case of DUP, in order to keep it simple,

				 * only add the mirror with the lowest physical

				 * address

				 */

				if (found &&

				    physical_of_found <=

				     bbio->stripes[i].physical)

					continue;

				index_srcdev = i;

				found = 1;

				physical_of_found = bbio->stripes[i].physical;

			}

		}

		if (found) {

			struct btrfs_bio_stripe *tgtdev_stripe =

				bbio->stripes + num_stripes;



			tgtdev_stripe->physical = physical_of_found;

			tgtdev_stripe->length =

				bbio->stripes[index_srcdev].length;

			tgtdev_stripe->dev = dev_replace->tgtdev;

			bbio->tgtdev_map[index_srcdev] = num_stripes;



			tgtdev_indexes++;

			num_stripes++;

		}

	}



	*num_stripes_ret = num_stripes;

	*max_errors_ret = max_errors;

	bbio->num_tgtdevs = tgtdev_indexes;

	*bbio_ret = bbio;

}



static int __btrfs_map_block(struct btrfs_fs_info *fs_info,

			     enum btrfs_map_op op,

			     u64 logical, u64 *length,
@@ -5812,86 +5906,10 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, 
	if (bbio->raid_map)

		sort_parity_stripes(bbio, num_stripes);



	tgtdev_indexes = 0;

	if (dev_replace_is_ongoing && op == BTRFS_MAP_WRITE &&

	    dev_replace->tgtdev != NULL) {

		int index_where_to_add;

		u64 srcdev_devid = dev_replace->srcdev->devid;



		/*

		 * duplicate the write operations while the dev replace

		 * procedure is running. Since the copying of the old disk

		 * to the new disk takes place at run time while the

		 * filesystem is mounted writable, the regular write

		 * operations to the old disk have to be duplicated to go

		 * to the new disk as well.

		 * Note that device->missing is handled by the caller, and

		 * that the write to the old disk is already set up in the

		 * stripes array.

		 */

		index_where_to_add = num_stripes;

		for (i = 0; i < num_stripes; i++) {

			if (bbio->stripes[i].dev->devid == srcdev_devid) {

				/* write to new disk, too */

				struct btrfs_bio_stripe *new =

					bbio->stripes + index_where_to_add;

				struct btrfs_bio_stripe *old =

					bbio->stripes + i;



				new->physical = old->physical;

				new->length = old->length;

				new->dev = dev_replace->tgtdev;

				bbio->tgtdev_map[i] = index_where_to_add;

				index_where_to_add++;

				max_errors++;

				tgtdev_indexes++;

			}

		}

		num_stripes = index_where_to_add;

	} else if (dev_replace_is_ongoing &&

		   op == BTRFS_MAP_GET_READ_MIRRORS &&

		   dev_replace->tgtdev != NULL) {

		u64 srcdev_devid = dev_replace->srcdev->devid;

		int index_srcdev = 0;

		int found = 0;

		u64 physical_of_found = 0;



		/*

		 * During the dev-replace procedure, the target drive can

		 * also be used to read data in case it is needed to repair

		 * a corrupt block elsewhere. This is possible if the

		 * requested area is left of the left cursor. In this area,

		 * the target drive is a full copy of the source drive.

		 */

		for (i = 0; i < num_stripes; i++) {

			if (bbio->stripes[i].dev->devid == srcdev_devid) {

				/*

				 * In case of DUP, in order to keep it

				 * simple, only add the mirror with the

				 * lowest physical address

				 */

				if (found &&

				    physical_of_found <=

				     bbio->stripes[i].physical)

					continue;

				index_srcdev = i;

				found = 1;

				physical_of_found = bbio->stripes[i].physical;

			}

		}

		if (found) {

			struct btrfs_bio_stripe *tgtdev_stripe =

				bbio->stripes + num_stripes;



			tgtdev_stripe->physical = physical_of_found;

			tgtdev_stripe->length =

				bbio->stripes[index_srcdev].length;

			tgtdev_stripe->dev = dev_replace->tgtdev;

			bbio->tgtdev_map[index_srcdev] = num_stripes;



			tgtdev_indexes++;

			num_stripes++;

		}

	if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL &&

	    (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS)) {

		handle_ops_on_dev_replace(op, &bbio, dev_replace, &num_stripes,

					  &max_errors);

	}



	*bbio_ret = bbio;
@@ -5899,7 +5917,6 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, 
	bbio->num_stripes = num_stripes;

	bbio->max_errors = max_errors;

	bbio->mirror_num = mirror_num;

	bbio->num_tgtdevs = tgtdev_indexes;



	/*

	 * this is the case that REQ_READ && dev_replace_is_ongoing &&