Commit 437490fe authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: tracepoints: output proper root owner for trace_find_free_extent() 



The current trace event always output result like this:

 find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=4(METADATA)
 find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=4(METADATA)
 find_free_extent: root=2(EXTENT_TREE) len=8192 empty_size=0 flags=1(DATA)
 find_free_extent: root=2(EXTENT_TREE) len=8192 empty_size=0 flags=1(DATA)
 find_free_extent: root=2(EXTENT_TREE) len=4096 empty_size=0 flags=1(DATA)
 find_free_extent: root=2(EXTENT_TREE) len=4096 empty_size=0 flags=1(DATA)

T's saying we're allocating data extent for EXTENT tree, which is not
even possible.

It's because we always use EXTENT tree as the owner for
trace_find_free_extent() without using the @root from
btrfs_reserve_extent().

This patch will change the parameter to use proper @root for
trace_find_free_extent():

Now it looks much better:

 find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP)
 find_free_extent: root=5(FS_TREE) len=8192 empty_size=0 flags=1(DATA)
 find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=1(DATA)
 find_free_extent: root=5(FS_TREE) len=4096 empty_size=0 flags=1(DATA)
 find_free_extent: root=5(FS_TREE) len=8192 empty_size=0 flags=1(DATA)
 find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP)
 find_free_extent: root=7(CSUM_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP)
 find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP)
 find_free_extent: root=1(ROOT_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP)

Reported-by: default avatarHans van Kranenburg <hans@knorrie.org>
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 549738f1

fs/btrfs/extent-tree.c

+4 −3
Original line number Diff line number Diff line
@@ -3918,11 +3918,12 @@ static int prepare_allocation(struct btrfs_fs_info *fs_info, 
 * |- Push harder to find free extents

 *    |- If not found, re-iterate all block groups

 */

static noinline int find_free_extent(struct btrfs_fs_info *fs_info,

static noinline int find_free_extent(struct btrfs_root *root,

				u64 ram_bytes, u64 num_bytes, u64 empty_size,

				u64 hint_byte_orig, struct btrfs_key *ins,

				u64 flags, int delalloc)

{

	struct btrfs_fs_info *fs_info = root->fs_info;

	int ret = 0;

	int cache_block_group_error = 0;

	struct btrfs_block_group *block_group = NULL;
@@ -3954,7 +3955,7 @@ static noinline int find_free_extent(struct btrfs_fs_info *fs_info, 
	ins->objectid = 0;

	ins->offset = 0;



	trace_find_free_extent(fs_info, num_bytes, empty_size, flags);

	trace_find_free_extent(root, num_bytes, empty_size, flags);



	space_info = btrfs_find_space_info(fs_info, flags);

	if (!space_info) {
@@ -4203,7 +4204,7 @@ int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes, 
	flags = get_alloc_profile_by_root(root, is_data);

again:

	WARN_ON(num_bytes < fs_info->sectorsize);

	ret = find_free_extent(fs_info, ram_bytes, num_bytes, empty_size,

	ret = find_free_extent(root, ram_bytes, num_bytes, empty_size,

			       hint_byte, ins, flags, delalloc);

	if (!ret && !is_data) {

		btrfs_dec_block_group_reservations(fs_info, ins->objectid);

include/trace/events/btrfs.h

+6 −4
Original line number Diff line number Diff line
@@ -1176,25 +1176,27 @@ DEFINE_EVENT(btrfs__reserved_extent, btrfs_reserved_extent_free, 


TRACE_EVENT(find_free_extent,



	TP_PROTO(const struct btrfs_fs_info *fs_info, u64 num_bytes,

	TP_PROTO(const struct btrfs_root *root, u64 num_bytes,

		 u64 empty_size, u64 data),



	TP_ARGS(fs_info, num_bytes, empty_size, data),

	TP_ARGS(root, num_bytes, empty_size, data),



	TP_STRUCT__entry_btrfs(

		__field(	u64,	root_objectid		)

		__field(	u64,	num_bytes		)

		__field(	u64,	empty_size		)

		__field(	u64,	data			)

	),



	TP_fast_assign_btrfs(fs_info,

	TP_fast_assign_btrfs(root->fs_info,

		__entry->root_objectid	= root->root_key.objectid;

		__entry->num_bytes	= num_bytes;

		__entry->empty_size	= empty_size;

		__entry->data		= data;

	),



	TP_printk_btrfs("root=%llu(%s) len=%llu empty_size=%llu flags=%llu(%s)",

		  show_root_type(BTRFS_EXTENT_TREE_OBJECTID),

		  show_root_type(__entry->root_objectid),

		  __entry->num_bytes, __entry->empty_size, __entry->data,

		  __print_flags((unsigned long)__entry->data, "|",

				 BTRFS_GROUP_FLAGS))