btrfs: add inode to truncate control

In the future we're going to want to use btrfs_truncate_inode_items
without looking up the associated inode.  In order to accommodate this
add the inode to btrfs_truncate_control and handle the case where
control->inode is NULL appropriately.  This is fairly straightforward,
we simply need to add a helper for the trace points, as the file extent
map update is controlled by a flag on btrfs_truncate_control.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/free-space-cache.c

@@ -292,6 +292,7 @@ int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
 				    struct inode *vfs_inode)
 {
 	struct btrfs_truncate_control control = {
+		.inode = BTRFS_I(vfs_inode),
 		.new_size = 0,
 		.ino = btrfs_ino(BTRFS_I(vfs_inode)),
 		.min_type = BTRFS_EXTENT_DATA_KEY,
@@ -339,7 +340,7 @@ int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
 	 * We skip the throttling logic for free space cache inodes, so we don't
 	 * need to check for -EAGAIN.
 	 */
-	ret = btrfs_truncate_inode_items(trans, root, inode, &control);
+	ret = btrfs_truncate_inode_items(trans, root, &control);
 
 	inode_sub_bytes(&inode->vfs_inode, control.sub_bytes);
 	btrfs_inode_safe_disk_i_size_write(inode, control.last_size);

fs/btrfs/inode-item.c

@@ -419,6 +419,20 @@ int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
 	return ret;
 }
 
+static inline void btrfs_trace_truncate(struct btrfs_inode *inode,
+					struct extent_buffer *leaf,
+					struct btrfs_file_extent_item *fi,
+					u64 offset, int extent_type, int slot)
+{
+	if (!inode)
+		return;
+	if (extent_type == BTRFS_FILE_EXTENT_INLINE)
+		trace_btrfs_truncate_show_fi_inline(inode, leaf, fi, slot,
+						    offset);
+	else
+		trace_btrfs_truncate_show_fi_regular(inode, leaf, fi, offset);
+}
+
 /*
  * Remove inode items from a given root.
  *
@@ -439,7 +453,6 @@ int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
  */
 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 			       struct btrfs_root *root,
-			       struct btrfs_inode *inode,
 			       struct btrfs_truncate_control *control)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -462,6 +475,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 	bool be_nice = false;
 	bool should_throttle = false;
 
+	ASSERT(control->inode || !control->clear_extent_range);
 	BUG_ON(new_size > 0 && control->min_type != BTRFS_EXTENT_DATA_KEY);
 
 	control->last_size = new_size;
@@ -526,19 +540,15 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 			fi = btrfs_item_ptr(leaf, path->slots[0],
 					    struct btrfs_file_extent_item);
 			extent_type = btrfs_file_extent_type(leaf, fi);
-			if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
+			if (extent_type != BTRFS_FILE_EXTENT_INLINE)
 				item_end +=
 				    btrfs_file_extent_num_bytes(leaf, fi);
-
-				trace_btrfs_truncate_show_fi_regular(
-					inode, leaf, fi, found_key.offset);
-			} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+			else if (extent_type == BTRFS_FILE_EXTENT_INLINE)
 				item_end += btrfs_file_extent_ram_bytes(leaf, fi);
 
-				trace_btrfs_truncate_show_fi_inline(
-					inode, leaf, fi, path->slots[0],
-					found_key.offset);
-			}
+			btrfs_trace_truncate(control->inode, leaf, fi,
+					     found_key.offset, extent_type,
+					     path->slots[0]);
 			item_end--;
 		}
 		if (found_type > control->min_type) {
@@ -628,7 +638,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 		 * normal truncate path.
 		 */
 		if (control->clear_extent_range) {
-			ret = btrfs_inode_clear_file_extent_range(inode,
+			ret = btrfs_inode_clear_file_extent_range(control->inode,
 						  clear_start, clear_len);
 			if (ret) {
 				btrfs_abort_transaction(trans, ret);

fs/btrfs/inode-item.h

@@ -20,6 +20,12 @@ struct extent_buffer;
 #define BTRFS_NEED_TRUNCATE_BLOCK		1
 
 struct btrfs_truncate_control {
+	/*
+	 * IN: the inode we're operating on, this can be NULL if
+	 * ->clear_extent_range is false.
+	 */
+	struct btrfs_inode *inode;
+
 	/* IN: the size we're truncating to. */
 	u64 new_size;
 
@@ -56,7 +62,6 @@ struct btrfs_truncate_control {
 
 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 			       struct btrfs_root *root,
-			       struct btrfs_inode *inode,
 			       struct btrfs_truncate_control *control);
 int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root,

fs/btrfs/inode.c

@@ -5252,6 +5252,7 @@ void btrfs_evict_inode(struct inode *inode)
 
 	while (1) {
 		struct btrfs_truncate_control control = {
+			.inode = BTRFS_I(inode),
 			.ino = btrfs_ino(BTRFS_I(inode)),
 			.new_size = 0,
 			.min_type = 0,
@@ -5263,8 +5264,7 @@ void btrfs_evict_inode(struct inode *inode)
 
 		trans->block_rsv = rsv;
 
-		ret = btrfs_truncate_inode_items(trans, root, BTRFS_I(inode),
-						 &control);
+		ret = btrfs_truncate_inode_items(trans, root, &control);
 		trans->block_rsv = &fs_info->trans_block_rsv;
 		btrfs_end_transaction(trans);
 		btrfs_btree_balance_dirty(fs_info);
@@ -8534,6 +8534,7 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
 static int btrfs_truncate(struct inode *inode, bool skip_writeback)
 {
 	struct btrfs_truncate_control control = {
+		.inode = BTRFS_I(inode),
 		.ino = btrfs_ino(BTRFS_I(inode)),
 		.min_type = BTRFS_EXTENT_DATA_KEY,
 		.clear_extent_range = true,
@@ -8621,8 +8622,7 @@ static int btrfs_truncate(struct inode *inode, bool skip_writeback)
 					ALIGN(new_size, fs_info->sectorsize),
 					(u64)-1, 0);
 
-		ret = btrfs_truncate_inode_items(trans, root, BTRFS_I(inode),
-						 &control);
+		ret = btrfs_truncate_inode_items(trans, root, &control);
 
 		inode_sub_bytes(inode, control.sub_bytes);
 		btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), control.last_size);

fs/btrfs/tree-log.c

@@ -4107,8 +4107,7 @@ static int truncate_inode_items(struct btrfs_trans_handle *trans,
 	int ret;
 
 	do {
-		ret = btrfs_truncate_inode_items(trans, log_root, inode,
-						 &control);
+		ret = btrfs_truncate_inode_items(trans, log_root, &control);
 	} while (ret == -EAGAIN);
 
 	return ret;