1 files changed, 58 insertions, 5 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 678154d4b78f..d20dbbe214e5 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2458,13 +2458,41 @@ static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
 			if (ret)
 				break;
 
-			/* for regular files, make sure corresponding
-			 * orphan item exist. extents past the new EOF
-			 * will be truncated later by orphan cleanup.
+			/*
+			 * Before replaying extents, truncate the inode to its
+			 * size. We need to do it now and not after log replay
+			 * because before an fsync we can have prealloc extents
+			 * added beyond the inode's i_size. If we did it after,
+			 * through orphan cleanup for example, we would drop
+			 * those prealloc extents just after replaying them.
 			 */
 			if (S_ISREG(mode)) {
-				ret = insert_orphan_item(wc->trans, root,
-							 key.objectid);
+				struct inode *inode;
+				u64 from;
+
+				inode = read_one_inode(root, key.objectid);
+				if (!inode) {
+					ret = -EIO;
+					break;
+				}
+				from = ALIGN(i_size_read(inode),
+					     root->fs_info->sectorsize);
+				ret = btrfs_drop_extents(wc->trans, root, inode,
+							 from, (u64)-1, 1);
+				/*
+				 * If the nlink count is zero here, the iput
+				 * will free the inode.  We bump it to make
+				 * sure it doesn't get freed until the link
+				 * count fixup is done.
+				 */
+				if (!ret) {
+					if (inode->i_nlink == 0)
+						inc_nlink(inode);
+					/* Update link count and nbytes. */
+					ret = btrfs_update_inode(wc->trans,
+								 root, inode);
+				}
+				iput(inode);
 				if (ret)
 					break;
 			}
@@ -4359,6 +4387,31 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
 		num++;
 	}
 
+	/*
+	 * Add all prealloc extents beyond the inode's i_size to make sure we
+	 * don't lose them after doing a fast fsync and replaying the log.
+	 */
+	if (inode->flags & BTRFS_INODE_PREALLOC) {
+		struct rb_node *node;
+
+		for (node = rb_last(&tree->map); node; node = rb_prev(node)) {
+			em = rb_entry(node, struct extent_map, rb_node);
+			if (em->start < i_size_read(&inode->vfs_inode))
+				break;
+			if (!list_empty(&em->list))
+				continue;
+			/* Same as above loop. */
+			if (++num > 32768) {
+				list_del_init(&tree->modified_extents);
+				ret = -EFBIG;
+				goto process;
+			}
+			refcount_inc(&em->refs);
+			set_bit(EXTENT_FLAG_LOGGING, &em->flags);
+			list_add_tail(&em->list, &extents);
+		}
+	}
+
 	list_sort(NULL, &extents, extent_cmp);
 	btrfs_get_logged_extents(inode, logged_list, logged_start, logged_end);
 	/*