From: Qu Wenruo <wqu@suse.com>
Date: Mon, 29 Apr 2019 14:03:33 +0800
Subject: btrfs: extent-tree: Add trace events for space info numbers update
Git-commit: 480b9b4d847fe18f4a559f5cac718d9b2cbcdcaf
Patch-mainline: v5.3-rc1
References: bsc#1165949
Add trace event for update_bytes_pinned() and update_bytes_may_use() to
detect underflow better.
The output would be something like (only showing data part):
## Buffered write start, 16K total ##
2255.954 xfs_io/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=0 diff=4096
2257.169 sudo/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=4096 diff=4096
2257.346 sudo/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=8192 diff=4096
2257.542 sudo/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=12288 diff=4096
## Delalloc start ##
3727.853 kworker/u8:3-e/700 btrfs:update_bytes_may_use:(nil)U: type=DATA old=16384 diff=-16384
## Space cache update ##
3733.132 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=0 diff=65536
3733.169 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=65536 diff=-65536
3739.868 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=0 diff=65536
3739.891 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=65536 diff=-65536
These two trace events will allow bcc tool to probe btrfs_space_info
changes and detect underflow with more details (e.g. backtrace for each
update).
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Acked-by: Nikolay Borisov <nborisov@suse.com>
---
fs/btrfs/extent-tree.c | 36 +++++++++++++++++--------------
include/trace/events/btrfs.h | 49 +++++++++++++++++++++++++++++++++++++++----
2 files changed, 65 insertions(+), 20 deletions(-)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -66,10 +66,12 @@ enum {
* Declare a helper function to detect underflow of various space info members
*/
#define DECLARE_SPACE_INFO_UPDATE(name) \
-static inline void update_##name(struct btrfs_space_info *sinfo, \
+static inline void update_##name(struct btrfs_fs_info *fs_info, \
+ struct btrfs_space_info *sinfo, \
s64 bytes) \
{ \
lockdep_assert_held(&sinfo->lock); \
+ trace_update_##name(fs_info, sinfo, sinfo->name, bytes); \
if (bytes < 0 && sinfo->name < -bytes) { \
WARN_ON(1); \
sinfo->name = 0; \
@@ -4422,7 +4424,7 @@ commit_trans:
data_sinfo->flags, bytes, 1);
return -ENOSPC;
}
- update_bytes_may_use(data_sinfo, bytes);
+ update_bytes_may_use(fs_info, data_sinfo, bytes);
trace_btrfs_space_reservation(fs_info, "space_info",
data_sinfo->flags, bytes, 1);
spin_unlock(&data_sinfo->lock);
@@ -4475,7 +4477,7 @@ void btrfs_free_reserved_data_space_noqu
data_sinfo = fs_info->data_sinfo;
spin_lock(&data_sinfo->lock);
- update_bytes_may_use(data_sinfo, -len);
+ update_bytes_may_use(fs_info, data_sinfo, -len);
trace_btrfs_space_reservation(fs_info, "space_info",
data_sinfo->flags, len, 0);
spin_unlock(&data_sinfo->lock);
@@ -5377,12 +5379,12 @@ static int __reserve_metadata_bytes(stru
* If not things get more complicated.
*/
if (used + orig_bytes <= space_info->total_bytes) {
- update_bytes_may_use(space_info, orig_bytes);
+ update_bytes_may_use(fs_info, space_info, orig_bytes);
trace_btrfs_space_reservation(fs_info, "space_info",
space_info->flags, orig_bytes, 1);
ret = 0;
} else if (can_overcommit(root, space_info, orig_bytes, flush)) {
- update_bytes_may_use(space_info, orig_bytes);
+ update_bytes_may_use(fs_info, space_info, orig_bytes);
trace_btrfs_space_reservation(fs_info, "space_info",
space_info->flags, orig_bytes, 1);
ret = 0;
@@ -5706,7 +5708,7 @@ again:
flush = BTRFS_RESERVE_FLUSH_ALL;
goto again;
}
- update_bytes_may_use(space_info, -num_bytes);
+ update_bytes_may_use(fs_info, space_info, -num_bytes);
trace_btrfs_space_reservation(fs_info, "space_info",
space_info->flags, num_bytes, 0);
spin_unlock(&space_info->lock);
@@ -5734,7 +5736,8 @@ again:
ticket->bytes, 1);
list_del_init(&ticket->list);
num_bytes -= ticket->bytes;
- update_bytes_may_use(space_info, ticket->bytes);
+ update_bytes_may_use(fs_info, space_info,
+ ticket->bytes);
ticket->bytes = 0;
space_info->tickets_id++;
wake_up(&ticket->wait);
@@ -5742,7 +5745,7 @@ again:
trace_btrfs_space_reservation(fs_info, "space_info",
space_info->flags,
num_bytes, 1);
- update_bytes_may_use(space_info, num_bytes);
+ update_bytes_may_use(fs_info, space_info, num_bytes);
ticket->bytes -= num_bytes;
num_bytes = 0;
}
@@ -6042,14 +6045,14 @@ static void update_global_block_rsv(stru
num_bytes = min(num_bytes,
block_rsv->size - block_rsv->reserved);
block_rsv->reserved += num_bytes;
- update_bytes_may_use(sinfo, num_bytes);
+ update_bytes_may_use(fs_info, sinfo, num_bytes);
trace_btrfs_space_reservation(fs_info, "space_info",
sinfo->flags, num_bytes,
1);
}
} else if (block_rsv->reserved > block_rsv->size) {
num_bytes = block_rsv->reserved - block_rsv->size;
- update_bytes_may_use(sinfo, -num_bytes);
+ update_bytes_may_use(fs_info, sinfo, -num_bytes);
trace_btrfs_space_reservation(fs_info, "space_info",
sinfo->flags, num_bytes, 0);
block_rsv->reserved = block_rsv->size;
@@ -6536,7 +6539,7 @@ static int update_block_group(struct btr
old_val -= num_bytes;
btrfs_set_block_group_used(&cache->item, old_val);
cache->pinned += num_bytes;
- update_bytes_pinned(cache->space_info, num_bytes);
+ update_bytes_pinned(info, cache->space_info, num_bytes);
cache->space_info->bytes_used -= num_bytes;
cache->space_info->disk_used -= num_bytes * factor;
spin_unlock(&cache->lock);
@@ -6617,7 +6620,7 @@ static int pin_down_extent(struct btrfs_
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
cache->pinned += num_bytes;
- update_bytes_pinned(cache->space_info, num_bytes);
+ update_bytes_pinned(fs_info, cache->space_info, num_bytes);
if (reserved) {
cache->reserved -= num_bytes;
cache->space_info->bytes_reserved -= num_bytes;
@@ -6834,7 +6837,7 @@ static int btrfs_add_reserved_bytes(stru
trace_btrfs_space_reservation(cache->fs_info,
"space_info", space_info->flags,
ram_bytes, 0);
- update_bytes_may_use(space_info, -ram_bytes);
+ update_bytes_may_use(cache->fs_info, space_info, -ram_bytes);
if (delalloc)
cache->delalloc_bytes += num_bytes;
}
@@ -6991,7 +6994,7 @@ static int unpin_extent_range(struct btr
spin_lock(&space_info->lock);
spin_lock(&cache->lock);
cache->pinned -= len;
- update_bytes_pinned(space_info, -len);
+ update_bytes_pinned(fs_info, space_info, -len);
trace_btrfs_space_reservation(fs_info, "pinned",
space_info->flags, len, 0);
@@ -7011,7 +7014,8 @@ static int unpin_extent_range(struct btr
to_add = min(len, global_rsv->size -
global_rsv->reserved);
global_rsv->reserved += to_add;
- update_bytes_may_use(space_info, to_add);
+ update_bytes_may_use(fs_info, space_info,
+ to_add);
if (global_rsv->reserved >= global_rsv->size)
global_rsv->full = 1;
trace_btrfs_space_reservation(fs_info,
@@ -11175,7 +11179,7 @@ void btrfs_delete_unused_bgs(struct btrf
spin_lock(&space_info->lock);
spin_lock(&block_group->lock);
- update_bytes_pinned(space_info, -block_group->pinned);
+ update_bytes_pinned(fs_info, space_info, -block_group->pinned);
space_info->bytes_readonly += block_group->pinned;
percpu_counter_add(&space_info->total_bytes_pinned,
-block_group->pinned);
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -27,6 +27,7 @@ struct __btrfs_workqueue;
struct btrfs_qgroup_extent_record;
struct btrfs_qgroup;
struct prelim_ref;
+struct btrfs_space_info;
#define show_ref_type(type) \
__print_symbolic(type, \
@@ -662,7 +663,7 @@ TRACE_EVENT(btrfs_add_block_group,
{ BTRFS_DROP_DELAYED_REF, "DROP_DELAYED_REF" }, \
{ BTRFS_ADD_DELAYED_EXTENT, "ADD_DELAYED_EXTENT" }, \
{ BTRFS_UPDATE_DELAYED_HEAD, "UPDATE_DELAYED_HEAD" })
-
+
DECLARE_EVENT_CLASS(btrfs_delayed_tree_ref,
@@ -676,7 +677,7 @@ DECLARE_EVENT_CLASS(btrfs_delayed_tree_r
TP_STRUCT__entry_btrfs(
__field( u64, bytenr )
__field( u64, num_bytes )
- __field( int, action )
+ __field( int, action )
__field( u64, parent )
__field( u64, ref_root )
__field( int, level )
@@ -739,7 +740,7 @@ DECLARE_EVENT_CLASS(btrfs_delayed_data_r
TP_STRUCT__entry_btrfs(
__field( u64, bytenr )
__field( u64, num_bytes )
- __field( int, action )
+ __field( int, action )
__field( u64, parent )
__field( u64, ref_root )
__field( u64, owner )
@@ -805,7 +806,7 @@ DECLARE_EVENT_CLASS(btrfs_delayed_ref_he
TP_STRUCT__entry_btrfs(
__field( u64, bytenr )
__field( u64, num_bytes )
- __field( int, action )
+ __field( int, action )
__field( int, is_data )
),
@@ -1802,6 +1803,46 @@ TRACE_EVENT(btrfs_inode_mod_outstanding_
show_root_type(__entry->root_objectid),
(unsigned long long)__entry->ino, __entry->mod)
);
+
+DECLARE_EVENT_CLASS(btrfs__space_info_update,
+
+ TP_PROTO(struct btrfs_fs_info *fs_info,
+ struct btrfs_space_info *sinfo, u64 old, s64 diff),
+
+ TP_ARGS(fs_info, sinfo, old, diff),
+
+ TP_STRUCT__entry_btrfs(
+ __field( u64, type )
+ __field( u64, old )
+ __field( s64, diff )
+ ),
+
+ TP_fast_assign_btrfs(fs_info,
+ __entry->type = sinfo->flags;
+ __entry->old = old;
+ __entry->diff = diff;
+ ),
+ TP_printk_btrfs("type=%s old=%llu diff=%lld",
+ __print_flags(__entry->type, "|", BTRFS_GROUP_FLAGS),
+ __entry->old, __entry->diff)
+);
+
+DEFINE_EVENT(btrfs__space_info_update, update_bytes_may_use,
+
+ TP_PROTO(struct btrfs_fs_info *fs_info,
+ struct btrfs_space_info *sinfo, u64 old, s64 diff),
+
+ TP_ARGS(fs_info, sinfo, old, diff)
+);
+
+DEFINE_EVENT(btrfs__space_info_update, update_bytes_pinned,
+
+ TP_PROTO(struct btrfs_fs_info *fs_info,
+ struct btrfs_space_info *sinfo, u64 old, s64 diff),
+
+ TP_ARGS(fs_info, sinfo, old, diff)
+);
+
#endif /* _TRACE_BTRFS_H */
/* This part must be outside protection */