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Commit 5378e607 authored by Li Dongyang's avatar Li Dongyang Committed by root
Browse files

Btrfs: adjust btrfs_discard_extent() return errors and trimmed bytes 



Callers of btrfs_discard_extent() should check if we are mounted with -o discard,
as we want to make fitrim to work even the fs is not mounted with -o discard.
Also we should use REQ_DISCARD to map the free extent to get a full mapping,
last we only return errors if
1. the error is not a EOPNOTSUPP
2. no device supports discard

Signed-off-by: default avatarLi Dongyang <lidongyang@novell.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent fce3bb9a

fs/btrfs/ctree.h

+1 −1
Original line number Diff line number Diff line
@@ -2229,7 +2229,7 @@ u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo); 
int btrfs_error_unpin_extent_range(struct btrfs_root *root,

				   u64 start, u64 end);

int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,

			       u64 num_bytes);

			       u64 num_bytes, u64 *actual_bytes);

int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,

			    struct btrfs_root *root, u64 type);

fs/btrfs/disk-io.c

+4 −1
Original line number Diff line number Diff line
@@ -3054,7 +3054,10 @@ static int btrfs_destroy_pinned_extent(struct btrfs_root *root, 
			break;



		/* opt_discard */

		ret = btrfs_error_discard_extent(root, start, end + 1 - start);

		if (btrfs_test_opt(root, DISCARD))

			ret = btrfs_error_discard_extent(root, start,

							 end + 1 - start,

							 NULL);



		clear_extent_dirty(unpin, start, end, GFP_NOFS);

		btrfs_error_unpin_extent_range(root, start, end);

fs/btrfs/extent-tree.c

+26 −17
Original line number Diff line number Diff line
@@ -1738,39 +1738,45 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans, 
	return ret;

}



static void btrfs_issue_discard(struct block_device *bdev,

static int btrfs_issue_discard(struct block_device *bdev,

				u64 start, u64 len)

{

	blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);

	return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);

}



static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,

				u64 num_bytes)

				u64 num_bytes, u64 *actual_bytes)

{

	int ret;

	u64 map_length = num_bytes;

	u64 discarded_bytes = 0;

	struct btrfs_multi_bio *multi = NULL;



	if (!btrfs_test_opt(root, DISCARD))

		return 0;



	/* Tell the block device(s) that the sectors can be discarded */

	ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,

			      bytenr, &map_length, &multi, 0);

	ret = btrfs_map_block(&root->fs_info->mapping_tree, REQ_DISCARD,

			      bytenr, &num_bytes, &multi, 0);

	if (!ret) {

		struct btrfs_bio_stripe *stripe = multi->stripes;

		int i;



		if (map_length > num_bytes)

			map_length = num_bytes;



		for (i = 0; i < multi->num_stripes; i++, stripe++) {

			btrfs_issue_discard(stripe->dev->bdev,

			ret = btrfs_issue_discard(stripe->dev->bdev,

						  stripe->physical,

					    map_length);

						  stripe->length);

			if (!ret)

				discarded_bytes += stripe->length;

			else if (ret != -EOPNOTSUPP)

				break;

		}

		kfree(multi);

	}

	if (discarded_bytes && ret == -EOPNOTSUPP)

		ret = 0;



	if (actual_bytes)

		*actual_bytes = discarded_bytes;





	return ret;

}
@@ -4371,7 +4377,9 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, 
		if (ret)

			break;



		ret = btrfs_discard_extent(root, start, end + 1 - start);

		if (btrfs_test_opt(root, DISCARD))

			ret = btrfs_discard_extent(root, start,

						   end + 1 - start, NULL);



		clear_extent_dirty(unpin, start, end, GFP_NOFS);

		unpin_extent_range(root, start, end);
@@ -5427,7 +5435,8 @@ int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len) 
		return -ENOSPC;

	}



	ret = btrfs_discard_extent(root, start, len);

	if (btrfs_test_opt(root, DISCARD))

		ret = btrfs_discard_extent(root, start, len, NULL);



	btrfs_add_free_space(cache, start, len);

	btrfs_update_reserved_bytes(cache, len, 0, 1);
@@ -8765,7 +8774,7 @@ int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end) 
}



int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,

			       u64 num_bytes)

			       u64 num_bytes, u64 *actual_bytes)

{

	return btrfs_discard_extent(root, bytenr, num_bytes);

	return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);

}