btrfs: use fs_info for btrfs_handle_em_exist tracepoint

We really want to know to which filesystem the extent map events belong,
but as it cannot be reached from the extent_map pointers, we need to
pass it down the callchain.
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/extent_map.c

@@ -518,6 +518,7 @@ static noinline int merge_extent_mapping(struct extent_map_tree *em_tree,
 
 /**
  * btrfs_add_extent_mapping - add extent mapping into em_tree
+ * @fs_info - used for tracepoint
  * @em_tree - the extent tree into which we want to insert the extent mapping
  * @em_in   - extent we are inserting
  * @start   - start of the logical range btrfs_get_extent() is requesting
@@ -535,7 +536,8 @@ static noinline int merge_extent_mapping(struct extent_map_tree *em_tree,
  * Return 0 on success, otherwise -EEXIST.
  *
  */
-int btrfs_add_extent_mapping(struct extent_map_tree *em_tree,
+int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
+			     struct extent_map_tree *em_tree,
 			     struct extent_map **em_in, u64 start, u64 len)
 {
 	int ret;
@@ -553,7 +555,7 @@ int btrfs_add_extent_mapping(struct extent_map_tree *em_tree,
 
 		existing = search_extent_mapping(em_tree, start, len);
 
-		trace_btrfs_handle_em_exist(existing, em, start, len);
+		trace_btrfs_handle_em_exist(fs_info, existing, em, start, len);
 
 		/*
 		 * existing will always be non-NULL, since there must be

fs/btrfs/extent_map.h

@@ -92,7 +92,8 @@ int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len, u64 gen
 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em);
 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
 					 u64 start, u64 len);
-int btrfs_add_extent_mapping(struct extent_map_tree *em_tree,
+int btrfs_add_extent_mapping(struct btrfs_fs_info *fs_info,
+			     struct extent_map_tree *em_tree,
 			     struct extent_map **em_in, u64 start, u64 len);
 
 #endif

fs/btrfs/inode.c

@@ -7083,7 +7083,7 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
 
 	err = 0;
 	write_lock(&em_tree->lock);
-	err = btrfs_add_extent_mapping(em_tree, &em, start, len);
+	err = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
 	write_unlock(&em_tree->lock);
 out:
 

fs/btrfs/tests/extent-map-tests.c

@@ -91,7 +91,7 @@ static void test_case_1(struct btrfs_fs_info *fs_info,
 	em->len = len;
 	em->block_start = start;
 	em->block_len = len;
-	ret = btrfs_add_extent_mapping(em_tree, &em, em->start, em->len);
+	ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, em->start, em->len);
 	if (ret)
 		test_msg("case1 [%llu %llu]: ret %d\n", start, start + len, ret);
 	if (em &&
@@ -155,7 +155,7 @@ static void test_case_2(struct btrfs_fs_info *fs_info,
 	em->len = SZ_1K;
 	em->block_start = EXTENT_MAP_INLINE;
 	em->block_len = (u64)-1;
-	ret = btrfs_add_extent_mapping(em_tree, &em, em->start, em->len);
+	ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, em->start, em->len);
 	if (ret)
 		test_msg("case2 [0 1K]: ret %d\n", ret);
 	if (em &&
@@ -201,7 +201,7 @@ static void __test_case_3(struct btrfs_fs_info *fs_info,
 	em->len = SZ_16K;
 	em->block_start = 0;
 	em->block_len = SZ_16K;
-	ret = btrfs_add_extent_mapping(em_tree, &em, start, len);
+	ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
 	if (ret)
 		test_msg("case3 [0x%llx 0x%llx): ret %d\n",
 			 start, start + len, ret);
@@ -288,7 +288,7 @@ static void __test_case_4(struct btrfs_fs_info *fs_info,
 	em->len = SZ_32K;
 	em->block_start = 0;
 	em->block_len = SZ_32K;
-	ret = btrfs_add_extent_mapping(em_tree, &em, start, len);
+	ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
 	if (ret)
 		test_msg("case4 [0x%llx 0x%llx): ret %d\n",
 			 start, len, ret);

include/trace/events/btrfs.h

@@ -256,11 +256,13 @@ TRACE_EVENT_CONDITION(btrfs_get_extent,
 
 TRACE_EVENT(btrfs_handle_em_exist,
 
-	TP_PROTO(const struct extent_map *existing, const struct extent_map *map, u64 start, u64 len),
+	TP_PROTO(struct btrfs_fs_info *fs_info,
+		const struct extent_map *existing, const struct extent_map *map,
+		u64 start, u64 len),
 
-	TP_ARGS(existing, map, start, len),
+	TP_ARGS(fs_info, existing, map, start, len),
 
-	TP_STRUCT__entry(
+	TP_STRUCT__entry_btrfs(
 		__field(	u64,  e_start		)
 		__field(	u64,  e_len		)
 		__field(	u64,  map_start		)
@@ -269,7 +271,7 @@ TRACE_EVENT(btrfs_handle_em_exist,
 		__field(	u64,  len		)
 	),
 
-	TP_fast_assign(
+	TP_fast_assign_btrfs(fs_info,
 		__entry->e_start	= existing->start;
 		__entry->e_len		= existing->len;
 		__entry->map_start	= map->start;
@@ -278,7 +280,7 @@ TRACE_EVENT(btrfs_handle_em_exist,
 		__entry->len		= len;
 	),
 
-	TP_printk("start=%llu len=%llu "
+	TP_printk_btrfs("start=%llu len=%llu "
 		  "existing(start=%llu len=%llu) "
 		  "em(start=%llu len=%llu)",
 		  __entry->start,