Btrfs: constify struct btrfs_{,disk_}key wherever possible

In a lot of places, it's unclear when it's safe to reuse a struct
btrfs_key after it has been passed to a helper function. Constify these
arguments wherever possible to make it obvious.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 31 insertions, 29 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0c8646217a71..56b8595eacbb 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1961,7 +1961,7 @@ BTRFS_SETGET_STACK_FUNCS(disk_key_offset, struct btrfs_disk_key, offset, 64);
 BTRFS_SETGET_STACK_FUNCS(disk_key_type, struct btrfs_disk_key, type, 8);
 
 static inline void btrfs_disk_key_to_cpu(struct btrfs_key *cpu,
-					 struct btrfs_disk_key *disk)
+					 const struct btrfs_disk_key *disk)
 {
 	cpu->offset = le64_to_cpu(disk->offset);
 	cpu->type = disk->type;
@@ -1969,7 +1969,7 @@ static inline void btrfs_disk_key_to_cpu(struct btrfs_key *cpu,
 }
 
 static inline void btrfs_cpu_key_to_disk(struct btrfs_disk_key *disk,
-					 struct btrfs_key *cpu)
+					 const struct btrfs_key *cpu)
 {
 	disk->offset = cpu_to_le64(cpu->offset);
 	disk->type = cpu->type;
@@ -2001,8 +2001,7 @@ static inline void btrfs_dir_item_key_to_cpu(struct extent_buffer *eb,
 	btrfs_disk_key_to_cpu(key, &disk_key);
 }
 
-
-static inline u8 btrfs_key_type(struct btrfs_key *key)
+static inline u8 btrfs_key_type(const struct btrfs_key *key)
 {
 	return key->type;
 }
@@ -2595,10 +2594,11 @@ void btrfs_get_block_group(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 int get_block_group_index(struct btrfs_block_group_cache *cache);
 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
-					struct btrfs_root *root, u64 parent,
-					u64 root_objectid,
-					struct btrfs_disk_key *key, int level,
-					u64 hint, u64 empty_size);
+					     struct btrfs_root *root,
+					     u64 parent, u64 root_objectid,
+					     const struct btrfs_disk_key *key,
+					     int level, u64 hint,
+					     u64 empty_size);
 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root,
 			   struct extent_buffer *buf,
@@ -2758,9 +2758,9 @@ u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
 		       struct btrfs_fs_info *info, u64 start, u64 end);
 
 /* ctree.c */
-int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
+int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
 		     int level, int *slot);
-int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2);
+int btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);
 int btrfs_previous_item(struct btrfs_root *root,
 			struct btrfs_path *path, u64 min_objectid,
 			int type);
@@ -2768,7 +2768,7 @@ int btrfs_previous_extent_item(struct btrfs_root *root,
 			struct btrfs_path *path, u64 min_objectid);
 void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info,
 			     struct btrfs_path *path,
-			     struct btrfs_key *new_key);
+			     const struct btrfs_key *new_key);
 struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
 struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root);
 int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
@@ -2810,22 +2810,23 @@ void btrfs_truncate_item(struct btrfs_fs_info *fs_info,
 int btrfs_split_item(struct btrfs_trans_handle *trans,
 		     struct btrfs_root *root,
 		     struct btrfs_path *path,
-		     struct btrfs_key *new_key,
+		     const struct btrfs_key *new_key,
 		     unsigned long split_offset);
 int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
 			 struct btrfs_root *root,
 			 struct btrfs_path *path,
-			 struct btrfs_key *new_key);
+			 const struct btrfs_key *new_key);
 int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path,
 		u64 inum, u64 ioff, u8 key_type, struct btrfs_key *found_key);
-int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
-		      *root, struct btrfs_key *key, struct btrfs_path *p, int
-		      ins_len, int cow);
-int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key,
+int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		      const struct btrfs_key *key, struct btrfs_path *p,
+		      int ins_len, int cow);
+int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
 			  struct btrfs_path *p, u64 time_seq);
 int btrfs_search_slot_for_read(struct btrfs_root *root,
-			       struct btrfs_key *key, struct btrfs_path *p,
-			       int find_higher, int return_any);
+			       const struct btrfs_key *key,
+			       struct btrfs_path *p, int find_higher,
+			       int return_any);
 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
 		       struct btrfs_root *root, struct extent_buffer *parent,
 		       int start_slot, u64 *last_ret,
@@ -2848,19 +2849,20 @@ static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
 }
 
 void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path,
-			    struct btrfs_key *cpu_key, u32 *data_size,
+			    const struct btrfs_key *cpu_key, u32 *data_size,
 			    u32 total_data, u32 total_size, int nr);
-int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
-		      *root, struct btrfs_key *key, void *data, u32 data_size);
+int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		      const struct btrfs_key *key, void *data, u32 data_size);
 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     struct btrfs_path *path,
-			     struct btrfs_key *cpu_key, u32 *data_size, int nr);
+			     const struct btrfs_key *cpu_key, u32 *data_size,
+			     int nr);
 
 static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
 					  struct btrfs_root *root,
 					  struct btrfs_path *path,
-					  struct btrfs_key *key,
+					  const struct btrfs_key *key,
 					  u32 data_size)
 {
 	return btrfs_insert_empty_items(trans, root, path, key, &data_size, 1);
@@ -2949,15 +2951,15 @@ int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
 		       u64 root_id, u64 ref_id, u64 dirid, u64 *sequence,
 		       const char *name, int name_len);
 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		   struct btrfs_key *key);
-int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
-		      *root, struct btrfs_key *key, struct btrfs_root_item
-		      *item);
+		   const struct btrfs_key *key);
+int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		      const struct btrfs_key *key,
+		      struct btrfs_root_item *item);
 int __must_check btrfs_update_root(struct btrfs_trans_handle *trans,
 				   struct btrfs_root *root,
 				   struct btrfs_key *key,
 				   struct btrfs_root_item *item);
-int btrfs_find_root(struct btrfs_root *root, struct btrfs_key *search_key,
+int btrfs_find_root(struct btrfs_root *root, const struct btrfs_key *search_key,
 		    struct btrfs_path *path, struct btrfs_root_item *root_item,
 		    struct btrfs_key *root_key);
 int btrfs_find_orphan_roots(struct btrfs_fs_info *fs_info);