btrfs: use struct qstr instead of name and namelen pairs

Many functions throughout btrfs take name buffer and name length
arguments. Most of these functions at the highest level are usually
called with these arguments extracted from a supplied dentry's name.
But the entire name can be passed instead, making each function a little
more elegant.

Each function whose arguments are currently the name and length
extracted from a dentry is herein converted to instead take a pointer to
the name in the dentry. The couple of calls to these calls without a
struct dentry are converted to create an appropriate qstr to pass in.
Additionally, every function which is only called with a name/len
extracted directly from a qstr is also converted.

This change has positive effect on stack consumption, frame of many
functions is reduced but this will be used in the future for fscrypt
related structures.

Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 36 insertions, 37 deletions

diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index b8dbabfa8b31..577e39cfc411 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -14,8 +14,8 @@
 #include "accessors.h"
 
 struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
-						   int slot, const char *name,
-						   int name_len)
+						   int slot,
+						   const struct qstr *name)
 {
 	struct btrfs_inode_ref *ref;
 	unsigned long ptr;
@@ -31,9 +31,10 @@ struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
 		len = btrfs_inode_ref_name_len(leaf, ref);
 		name_ptr = (unsigned long)(ref + 1);
 		cur_offset += len + sizeof(*ref);
-		if (len != name_len)
+		if (len != name->len)
 			continue;
-		if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
+		if (memcmp_extent_buffer(leaf, name->name, name_ptr,
+					 name->len) == 0)
 			return ref;
 	}
 	return NULL;
@@ -41,7 +42,7 @@ struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
 
 struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
 		struct extent_buffer *leaf, int slot, u64 ref_objectid,
-		const char *name, int name_len)
+		const struct qstr *name)
 {
 	struct btrfs_inode_extref *extref;
 	unsigned long ptr;
@@ -64,9 +65,10 @@ struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
 		name_ptr = (unsigned long)(&extref->name);
 		ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
 
-		if (ref_name_len == name_len &&
+		if (ref_name_len == name->len &&
 		    btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
-		    (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0))
+		    (memcmp_extent_buffer(leaf, name->name, name_ptr,
+					  name->len) == 0))
 			return extref;
 
 		cur_offset += ref_name_len + sizeof(*extref);
@@ -79,7 +81,7 @@ struct btrfs_inode_extref *
 btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root,
 			  struct btrfs_path *path,
-			  const char *name, int name_len,
+			  const struct qstr *name,
 			  u64 inode_objectid, u64 ref_objectid, int ins_len,
 			  int cow)
 {
@@ -88,7 +90,7 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 
 	key.objectid = inode_objectid;
 	key.type = BTRFS_INODE_EXTREF_KEY;
-	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
 
 	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 	if (ret < 0)
@@ -96,13 +98,13 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 	if (ret > 0)
 		return NULL;
 	return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
-					      ref_objectid, name, name_len);
+					      ref_objectid, name);
 
 }
 
 static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
 				  struct btrfs_root *root,
-				  const char *name, int name_len,
+				  const struct qstr *name,
 				  u64 inode_objectid, u64 ref_objectid,
 				  u64 *index)
 {
@@ -111,14 +113,14 @@ static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
 	struct btrfs_inode_extref *extref;
 	struct extent_buffer *leaf;
 	int ret;
-	int del_len = name_len + sizeof(*extref);
+	int del_len = name->len + sizeof(*extref);
 	unsigned long ptr;
 	unsigned long item_start;
 	u32 item_size;
 
 	key.objectid = inode_objectid;
 	key.type = BTRFS_INODE_EXTREF_KEY;
-	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -136,7 +138,7 @@ static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
 	 * readonly.
 	 */
 	extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
-						ref_objectid, name, name_len);
+						ref_objectid, name);
 	if (!extref) {
 		btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
 		ret = -EROFS;
@@ -172,8 +174,7 @@ out:
 }
 
 int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
-			struct btrfs_root *root,
-			const char *name, int name_len,
+			struct btrfs_root *root, const struct qstr *name,
 			u64 inode_objectid, u64 ref_objectid, u64 *index)
 {
 	struct btrfs_path *path;
@@ -186,7 +187,7 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
 	u32 sub_item_len;
 	int ret;
 	int search_ext_refs = 0;
-	int del_len = name_len + sizeof(*ref);
+	int del_len = name->len + sizeof(*ref);
 
 	key.objectid = inode_objectid;
 	key.offset = ref_objectid;
@@ -205,8 +206,7 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
 		goto out;
 	}
 
-	ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name,
-					 name_len);
+	ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name);
 	if (!ref) {
 		ret = -ENOENT;
 		search_ext_refs = 1;
@@ -223,7 +223,7 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
 		goto out;
 	}
 	ptr = (unsigned long)ref;
-	sub_item_len = name_len + sizeof(*ref);
+	sub_item_len = name->len + sizeof(*ref);
 	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
 	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
 			      item_size - (ptr + sub_item_len - item_start));
@@ -237,7 +237,7 @@ out:
 		 * name in our ref array. Find and remove the extended
 		 * inode ref then.
 		 */
-		return btrfs_del_inode_extref(trans, root, name, name_len,
+		return btrfs_del_inode_extref(trans, root, name,
 					      inode_objectid, ref_objectid, index);
 	}
 
@@ -251,12 +251,13 @@ out:
  */
 static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
 				     struct btrfs_root *root,
-				     const char *name, int name_len,
-				     u64 inode_objectid, u64 ref_objectid, u64 index)
+				     const struct qstr *name,
+				     u64 inode_objectid, u64 ref_objectid,
+				     u64 index)
 {
 	struct btrfs_inode_extref *extref;
 	int ret;
-	int ins_len = name_len + sizeof(*extref);
+	int ins_len = name->len + sizeof(*extref);
 	unsigned long ptr;
 	struct btrfs_path *path;
 	struct btrfs_key key;
@@ -264,7 +265,7 @@ static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
 
 	key.objectid = inode_objectid;
 	key.type = BTRFS_INODE_EXTREF_KEY;
-	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -276,7 +277,7 @@ static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
 		if (btrfs_find_name_in_ext_backref(path->nodes[0],
 						   path->slots[0],
 						   ref_objectid,
-						   name, name_len))
+						   name))
 			goto out;
 
 		btrfs_extend_item(path, ins_len);
@@ -290,12 +291,12 @@ static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
 	ptr += btrfs_item_size(leaf, path->slots[0]) - ins_len;
 	extref = (struct btrfs_inode_extref *)ptr;
 
-	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
+	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name->len);
 	btrfs_set_inode_extref_index(path->nodes[0], extref, index);
 	btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
 
 	ptr = (unsigned long)&extref->name;
-	write_extent_buffer(path->nodes[0], name, ptr, name_len);
+	write_extent_buffer(path->nodes[0], name->name, ptr, name->len);
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 
 out:
@@ -305,8 +306,7 @@ out:
 
 /* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
 int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root,
-			   const char *name, int name_len,
+			   struct btrfs_root *root, const struct qstr *name,
 			   u64 inode_objectid, u64 ref_objectid, u64 index)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -315,7 +315,7 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 	struct btrfs_inode_ref *ref;
 	unsigned long ptr;
 	int ret;
-	int ins_len = name_len + sizeof(*ref);
+	int ins_len = name->len + sizeof(*ref);
 
 	key.objectid = inode_objectid;
 	key.offset = ref_objectid;
@@ -331,7 +331,7 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 	if (ret == -EEXIST) {
 		u32 old_size;
 		ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
-						 name, name_len);
+						 name);
 		if (ref)
 			goto out;
 
@@ -340,7 +340,7 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
 				     struct btrfs_inode_ref);
 		ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
-		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len);
 		btrfs_set_inode_ref_index(path->nodes[0], ref, index);
 		ptr = (unsigned long)(ref + 1);
 		ret = 0;
@@ -348,7 +348,7 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 		if (ret == -EOVERFLOW) {
 			if (btrfs_find_name_in_backref(path->nodes[0],
 						       path->slots[0],
-						       name, name_len))
+						       name))
 				ret = -EEXIST;
 			else
 				ret = -EMLINK;
@@ -357,11 +357,11 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 	} else {
 		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
 				     struct btrfs_inode_ref);
-		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len);
 		btrfs_set_inode_ref_index(path->nodes[0], ref, index);
 		ptr = (unsigned long)(ref + 1);
 	}
-	write_extent_buffer(path->nodes[0], name, ptr, name_len);
+	write_extent_buffer(path->nodes[0], name->name, ptr, name->len);
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 
 out:
@@ -374,7 +374,6 @@ out:
 		if (btrfs_super_incompat_flags(disk_super)
 		    & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
 			ret = btrfs_insert_inode_extref(trans, root, name,
-							name_len,
 							inode_objectid,
 							ref_objectid, index);
 	}