btrfs: generate lockdep keyset names at compile time

The names in btrfs_lockdep_keysets are generated from a simple pattern
using snprintf but we can generate them directly with some macro magic
and remove the helpers.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/disk-io.c

@@ -150,40 +150,42 @@ struct async_submit_bio {
 #  error
 # endif
 
+#define DEFINE_LEVEL(stem, level)					\
+	.names[level] = "btrfs-" stem "-0" #level,
+
+#define DEFINE_NAME(stem)						\
+	DEFINE_LEVEL(stem, 0)						\
+	DEFINE_LEVEL(stem, 1)						\
+	DEFINE_LEVEL(stem, 2)						\
+	DEFINE_LEVEL(stem, 3)						\
+	DEFINE_LEVEL(stem, 4)						\
+	DEFINE_LEVEL(stem, 5)						\
+	DEFINE_LEVEL(stem, 6)						\
+	DEFINE_LEVEL(stem, 7)
+
 static struct btrfs_lockdep_keyset {
 	u64			id;		/* root objectid */
-	const char		*name_stem;	/* lock name stem */
+	/* Longest entry: btrfs-free-space-00 */
 	char			names[BTRFS_MAX_LEVEL][20];
 	struct lock_class_key	keys[BTRFS_MAX_LEVEL];
 } btrfs_lockdep_keysets[] = {
-	{ .id = BTRFS_ROOT_TREE_OBJECTID,	.name_stem = "root"	},
-	{ .id = BTRFS_EXTENT_TREE_OBJECTID,	.name_stem = "extent"	},
-	{ .id = BTRFS_CHUNK_TREE_OBJECTID,	.name_stem = "chunk"	},
-	{ .id = BTRFS_DEV_TREE_OBJECTID,	.name_stem = "dev"	},
-	{ .id = BTRFS_FS_TREE_OBJECTID,		.name_stem = "fs"	},
-	{ .id = BTRFS_CSUM_TREE_OBJECTID,	.name_stem = "csum"	},
-	{ .id = BTRFS_QUOTA_TREE_OBJECTID,	.name_stem = "quota"	},
-	{ .id = BTRFS_TREE_LOG_OBJECTID,	.name_stem = "log"	},
-	{ .id = BTRFS_TREE_RELOC_OBJECTID,	.name_stem = "treloc"	},
-	{ .id = BTRFS_DATA_RELOC_TREE_OBJECTID,	.name_stem = "dreloc"	},
-	{ .id = BTRFS_UUID_TREE_OBJECTID,	.name_stem = "uuid"	},
-	{ .id = BTRFS_FREE_SPACE_TREE_OBJECTID,	.name_stem = "free-space" },
-	{ .id = 0,				.name_stem = "tree"	},
+	{ .id = BTRFS_ROOT_TREE_OBJECTID,	DEFINE_NAME("root")	},
+	{ .id = BTRFS_EXTENT_TREE_OBJECTID,	DEFINE_NAME("extent")	},
+	{ .id = BTRFS_CHUNK_TREE_OBJECTID,	DEFINE_NAME("chunk")	},
+	{ .id = BTRFS_DEV_TREE_OBJECTID,	DEFINE_NAME("dev")	},
+	{ .id = BTRFS_FS_TREE_OBJECTID,		DEFINE_NAME("fs")	},
+	{ .id = BTRFS_CSUM_TREE_OBJECTID,	DEFINE_NAME("csum")	},
+	{ .id = BTRFS_QUOTA_TREE_OBJECTID,	DEFINE_NAME("quota")	},
+	{ .id = BTRFS_TREE_LOG_OBJECTID,	DEFINE_NAME("log")	},
+	{ .id = BTRFS_TREE_RELOC_OBJECTID,	DEFINE_NAME("treloc")	},
+	{ .id = BTRFS_DATA_RELOC_TREE_OBJECTID,	DEFINE_NAME("dreloc")	},
+	{ .id = BTRFS_UUID_TREE_OBJECTID,	DEFINE_NAME("uuid")	},
+	{ .id = BTRFS_FREE_SPACE_TREE_OBJECTID,	DEFINE_NAME("free-space") },
+	{ .id = 0,				DEFINE_NAME("tree")	},
 };
 
-void __init btrfs_init_lockdep(void)
-{
-	int i, j;
-
-	/* initialize lockdep class names */
-	for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
-		struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
-
-		for (j = 0; j < ARRAY_SIZE(ks->names); j++)
-			snprintf(ks->names[j], sizeof(ks->names[j]),
-				 "btrfs-%s-%02d", ks->name_stem, j);
-	}
-}
+#undef DEFINE_LEVEL
+#undef DEFINE_NAME
 
 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
 				    int level)

fs/btrfs/disk-io.h

@@ -135,12 +135,9 @@ int __init btrfs_end_io_wq_init(void);
 void __cold btrfs_end_io_wq_exit(void);
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
-void btrfs_init_lockdep(void);
 void btrfs_set_buffer_lockdep_class(u64 objectid,
 			            struct extent_buffer *eb, int level);
 #else
-static inline void btrfs_init_lockdep(void)
-{ }
 static inline void btrfs_set_buffer_lockdep_class(u64 objectid,
 					struct extent_buffer *eb, int level)
 {

fs/btrfs/super.c

@@ -2572,8 +2572,6 @@ static int __init init_btrfs_fs(void)
 	if (err)
 		goto free_end_io_wq;
 
-	btrfs_init_lockdep();
-
 	btrfs_print_mod_info();
 
 	err = btrfs_run_sanity_tests();