From 5378e60734f5b7bfe1b43dc191aaf6131c1befe7 Mon Sep 17 00:00:00 2001 From: Li Dongyang Date: Thu, 24 Mar 2011 10:24:27 +0000 Subject: [PATCH] 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: Li Dongyang Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 2 +- fs/btrfs/disk-io.c | 5 ++++- fs/btrfs/extent-tree.c | 43 +++++++++++++++++++++++++----------------- 3 files changed, 31 insertions(+), 19 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 9e21176cdf57..a18b7bc2b22c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -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); diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 125639ddaffe..8ecc5419d8b6 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -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); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 0671f5b77eb8..e990d2d1ba4a 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -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, - stripe->physical, - map_length); + ret = btrfs_issue_discard(stripe->dev->bdev, + stripe->physical, + 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); } -- 2.30.2