1 files changed, 35 insertions, 20 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d6e43c94436d..27aaa5064ff7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3197,8 +3197,23 @@ out:
 			unwritten_start += logical_len;
 		clear_extent_uptodate(io_tree, unwritten_start, end, NULL);
 
-		/* Drop the cache for the part of the extent we didn't write. */
-		btrfs_drop_extent_cache(inode, unwritten_start, end, 0);
+		/*
+		 * Drop extent maps for the part of the extent we didn't write.
+		 *
+		 * We have an exception here for the free_space_inode, this is
+		 * because when we do btrfs_get_extent() on the free space inode
+		 * we will search the commit root.  If this is a new block group
+		 * we won't find anything, and we will trip over the assert in
+		 * writepage where we do ASSERT(em->block_start !=
+		 * EXTENT_MAP_HOLE).
+		 *
+		 * Theoretically we could also skip this for any NOCOW extent as
+		 * we don't mess with the extent map tree in the NOCOW case, but
+		 * for now simply skip this if we are the free space inode.
+		 */
+		if (!btrfs_is_free_space_inode(inode))
+			btrfs_drop_extent_cache(inode, unwritten_start,
+						    end, 0);
 
 		/*
 		 * If the ordered extent had an IOERR or something else went
@@ -4640,7 +4655,6 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 	struct inode *inode = d_inode(dentry);
 	int err = 0;
 	struct btrfs_trans_handle *trans;
-	u64 last_unlink_trans;
 
 	if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
 		return -ENOTEMPTY;
@@ -4651,6 +4665,23 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 	if (IS_ERR(trans))
 		return PTR_ERR(trans);
 
+	/*
+	 * Propagate the last_unlink_trans value of the deleted dir to its
+	 * parent directory. This is to prevent an unrecoverable log tree in the
+	 * case we do something like this:
+	 * 1) create dir foo
+	 * 2) create snapshot under dir foo
+	 * 3) delete the snapshot
+	 * 4) rmdir foo
+	 * 5) mkdir foo
+	 * 6) fsync foo or some file inside foo
+	 *
+	 * This is because we can't unlink other roots when replaying the dir
+	 * deletes for directory foo.
+	 */
+	if (BTRFS_I(inode)->last_unlink_trans >= trans->transid)
+		btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
+
 	if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
 		err = btrfs_unlink_subvol(trans, dir, dentry);
 		goto out;
@@ -4660,28 +4691,12 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 	if (err)
 		goto out;
 
-	last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
-
 	/* now the directory is empty */
 	err = btrfs_unlink_inode(trans, BTRFS_I(dir),
 			BTRFS_I(d_inode(dentry)), dentry->d_name.name,
 			dentry->d_name.len);
-	if (!err) {
+	if (!err)
 		btrfs_i_size_write(BTRFS_I(inode), 0);
-		/*
-		 * Propagate the last_unlink_trans value of the deleted dir to
-		 * its parent directory. This is to prevent an unrecoverable
-		 * log tree in the case we do something like this:
-		 * 1) create dir foo
-		 * 2) create snapshot under dir foo
-		 * 3) delete the snapshot
-		 * 4) rmdir foo
-		 * 5) mkdir foo
-		 * 6) fsync foo or some file inside foo
-		 */
-		if (last_unlink_trans >= trans->transid)
-			BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
-	}
 out:
 	btrfs_end_transaction(trans);
 	btrfs_btree_balance_dirty(BTRFS_I(dir)->root->fs_info);