This is a note to let you know that I've just added the patch titled
btrfs: tracepoints: output proper root owner for trace_find_free_extent()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btrfs-tracepoints-output-proper-root-owner-for-trace.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8774930cf30f217de1e57c6f2aff373ef5af9f55
Author: Qu Wenruo <wqu@xxxxxxxx>
Date: Tue Jul 28 09:42:49 2020 +0800
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: Hans van Kranenburg <hans@xxxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx # 5.4+
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 388449101705e..c6d9e8c07c236 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3800,11 +3800,12 @@ static int find_free_extent_update_loop(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, 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_free_cluster *last_ptr = NULL;
@@ -3833,7 +3834,7 @@ 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) {
@@ -4141,7 +4142,7 @@ 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);
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 75ae1899452b9..94a3adb65b8af 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -1159,25 +1159,27 @@ 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))
