1 files changed, 46 insertions, 14 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4d4e2de3e879..f0e41b840739 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2562,8 +2562,10 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
 	struct extent_state *cached_state = NULL;
 	struct new_sa_defrag_extent *new = NULL;
 	int compress_type = 0;
-	int ret;
+	int ret = 0;
+	u64 logical_len = ordered_extent->len;
 	bool nolock;
+	bool truncated = false;
 
 	nolock = btrfs_is_free_space_inode(inode);
 
@@ -2572,6 +2574,14 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
 		goto out;
 	}
 
+	if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
+		truncated = true;
+		logical_len = ordered_extent->truncated_len;
+		/* Truncated the entire extent, don't bother adding */
+		if (!logical_len)
+			goto out;
+	}
+
 	if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
 		BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
 		btrfs_ordered_update_i_size(inode, 0, ordered_extent);
@@ -2627,15 +2637,14 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
 		ret = btrfs_mark_extent_written(trans, inode,
 						ordered_extent->file_offset,
 						ordered_extent->file_offset +
-						ordered_extent->len);
+						logical_len);
 	} else {
 		BUG_ON(root == root->fs_info->tree_root);
 		ret = insert_reserved_file_extent(trans, inode,
 						ordered_extent->file_offset,
 						ordered_extent->start,
 						ordered_extent->disk_len,
-						ordered_extent->len,
-						ordered_extent->len,
+						logical_len, logical_len,
 						compress_type, 0, 0,
 						BTRFS_FILE_EXTENT_REG);
 	}
@@ -2667,17 +2676,27 @@ out:
 	if (trans)
 		btrfs_end_transaction(trans, root);
 
-	if (ret) {
-		clear_extent_uptodate(io_tree, ordered_extent->file_offset,
-				      ordered_extent->file_offset +
-				      ordered_extent->len - 1, NULL, GFP_NOFS);
+	if (ret || truncated) {
+		u64 start, end;
+
+		if (truncated)
+			start = ordered_extent->file_offset + logical_len;
+		else
+			start = ordered_extent->file_offset;
+		end = ordered_extent->file_offset + ordered_extent->len - 1;
+		clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
+
+		/* Drop the cache for the part of the extent we didn't write. */
+		btrfs_drop_extent_cache(inode, start, end, 0);
 
 		/*
 		 * If the ordered extent had an IOERR or something else went
 		 * wrong we need to return the space for this ordered extent
-		 * back to the allocator.
+		 * back to the allocator.  We only free the extent in the
+		 * truncated case if we didn't write out the extent at all.
 		 */
-		if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
+		if ((ret || !logical_len) &&
+		    !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
 		    !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
 			btrfs_free_reserved_extent(root, ordered_extent->start,
 						   ordered_extent->disk_len);
@@ -7336,10 +7355,23 @@ static void btrfs_invalidatepage(struct page *page, unsigned int offset,
 		 * whoever cleared the private bit is responsible
 		 * for the finish_ordered_io
 		 */
-		if (TestClearPagePrivate2(page) &&
-		    btrfs_dec_test_ordered_pending(inode, &ordered, page_start,
-						   PAGE_CACHE_SIZE, 1)) {
-			btrfs_finish_ordered_io(ordered);
+		if (TestClearPagePrivate2(page)) {
+			struct btrfs_ordered_inode_tree *tree;
+			u64 new_len;
+
+			tree = &BTRFS_I(inode)->ordered_tree;
+
+			spin_lock_irq(&tree->lock);
+			set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
+			new_len = page_start - ordered->file_offset;
+			if (new_len < ordered->truncated_len)
+				ordered->truncated_len = new_len;
+			spin_unlock_irq(&tree->lock);
+
+			if (btrfs_dec_test_ordered_pending(inode, &ordered,
+							   page_start,
+							   PAGE_CACHE_SIZE, 1))
+				btrfs_finish_ordered_io(ordered);
 		}
 		btrfs_put_ordered_extent(ordered);
 		cached_state = NULL;