Although btrfs heavily relies on extent_io_tree, we don't really have
any good trace events for them.
This patch will add the folowing trace events:
trace_btrfs_set_extent_bit()
trace_btrfs_clear_extent_bit()
trace_btrfs_convert_extent_bit()
Since selftest could create temporary extent_io_tree without fs_info,
modify TP_fast_assign_fsid() to accept NULL as fs_info.
NULL fs_info will lead to all zero fsid.
The output would be:
btrfs_set_extent_bit: <FDID>: io_tree=IO_TREE ino=1 root=1 start=22036480 len=4096 set_bits=LOCKED
btrfs_set_extent_bit: <FSID>: io_tree=IO_TREE ino=1 root=1 start=22040576 len=4096 set_bits=LOCKED
btrfs_set_extent_bit: <FSID>: io_tree=IO_TREE ino=1 root=1 start=22044672 len=4096 set_bits=LOCKED
btrfs_set_extent_bit: <FSID>: io_tree=IO_TREE ino=1 root=1 start=22048768 len=4096 set_bits=LOCKED
btrfs_clear_extent_bit: <FSID>: io_tree=IO_TREE ino=1 root=1 start=22036480 len=16384 clear_bits=LOCKED
^^^ Extent buffer 22036480 read from disc, the locking progress
btrfs_set_extent_bit: <FSID>: io_tree=TRANS_DIRTY_PAGES ino=1 root=1 start=30425088 len=16384 set_bits=DIRTY
btrfs_set_extent_bit: <FSID>: io_tree=TRANS_DIRTY_PAGES ino=1 root=1 start=30441472 len=16384 set_bits=DIRTY
^^^ 2 new tree blocks allocated in one transaction
btrfs_set_extent_bit: <FSID>: io_tree=FREED_EXTENTS0 ino=0 root=0 start=30523392 len=16384 set_bits=DIRTY
btrfs_set_extent_bit: <FSID>: io_tree=FREED_EXTENTS0 ino=0 root=0 start=30556160 len=16384 set_bits=DIRTY
^^^ 2 old tree blocks get pinned down
There is one point which need extra attention:
1) Those trace events are pretty heavy
The following workload would generate over 400 trace events.
mkfs.btrfs -f $dev
start_trace
mount $dev $mnt -o enospc_debug
sync
touch $mnt/file1
touch $mnt/file2
touch $mnt/file3
xfs_io -f -c "pwrite 0 16k" $mnt/file4
umount $mnt
end_trace
It's not recommended to use them in real world environment.
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
---
fs/btrfs/extent_io.c | 4 +
include/trace/events/btrfs.h | 159 ++++++++++++++++++++++++++++++++++-
2 files changed, 162 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index dd2cfd054eef..d9ef31def740 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -582,6 +582,7 @@ int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
int clear = 0;
btrfs_debug_check_extent_io_range(tree, start, end);
+ trace_btrfs_clear_extent_bit(tree, start, end - start + 1, bits);
if (bits & EXTENT_DELALLOC)
bits |= EXTENT_NORESERVE;
@@ -852,6 +853,7 @@ __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
u64 last_end;
btrfs_debug_check_extent_io_range(tree, start, end);
+ trace_btrfs_set_extent_bit(tree, start, end - start + 1, bits);
bits |= EXTENT_FIRST_DELALLOC;
again:
@@ -1085,6 +1087,8 @@ int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
bool first_iteration = true;
btrfs_debug_check_extent_io_range(tree, start, end);
+ trace_btrfs_convert_extent_bit(tree, start, end - start + 1, bits,
+ clear_bits);
again:
if (!prealloc) {
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 2887503e4d12..2b4779b1855a 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -27,6 +27,7 @@ struct btrfs_work;
struct __btrfs_workqueue;
struct btrfs_qgroup_extent_record;
struct btrfs_qgroup;
+struct extent_io_tree;
struct prelim_ref;
TRACE_DEFINE_ENUM(FLUSH_DELAYED_ITEMS_NR);
@@ -77,6 +78,17 @@ TRACE_DEFINE_ENUM(COMMIT_TRANS);
{ BTRFS_QGROUP_RSV_META_PERTRANS, "META_PERTRANS" }, \
{ BTRFS_QGROUP_RSV_META_PREALLOC, "META_PREALLOC" })
+#define show_extent_io_tree_owner(owner) \
+ __print_symbolic(owner, \
+ { IO_TREE_FS_INFO_FREED_EXTENTS0, "FREED_EXTENTS0" }, \
+ { IO_TREE_FS_INFO_FREED_EXTENTS1, "FREED_EXTENTS1" }, \
+ { IO_TREE_INODE_IO_TREE, "IO_TREE" }, \
+ { IO_TREE_INODE_IO_FAILURE_TREE, "IO_FAILURE_TREE" }, \
+ { IO_TREE_RELOC_BLOCKS, "RELOCATION" }, \
+ { IO_TREE_TRANSACTION_DIRTY_PAGES, "TRANS_DIRTY_PAGES" },\
+ { IO_TREE_ROOT_DIRTY_LOG_PAGES, "ROOT_DIRTY_LOG" }, \
+ { IO_TREE_SELFTEST_TMP, "SELFTEST_TMP" })
+
#define BTRFS_GROUP_FLAGS \
{ BTRFS_BLOCK_GROUP_DATA, "DATA"}, \
{ BTRFS_BLOCK_GROUP_SYSTEM, "SYSTEM"}, \
@@ -88,11 +100,36 @@ TRACE_DEFINE_ENUM(COMMIT_TRANS);
{ BTRFS_BLOCK_GROUP_RAID5, "RAID5"}, \
{ BTRFS_BLOCK_GROUP_RAID6, "RAID6"}
+#define EXTENT_FLAGS \
+ { EXTENT_DIRTY, "DIRTY"}, \
+ { EXTENT_WRITEBACK, "WRITEBACK"}, \
+ { EXTENT_UPTODATE, "UPTODATE"}, \
+ { EXTENT_LOCKED, "LOCKED"}, \
+ { EXTENT_NEW, "NEW"}, \
+ { EXTENT_DELALLOC, "DELALLOC"}, \
+ { EXTENT_DEFRAG, "DEFRAG"}, \
+ { EXTENT_BOUNDARY, "BOUNDARY"}, \
+ { EXTENT_NODATASUM, "NODATASUM"}, \
+ { EXTENT_CLEAR_META_RESV, "CLEAR_META_RSV"}, \
+ { EXTENT_FIRST_DELALLOC, "FIRST_DELALLOC"}, \
+ { EXTENT_NEED_WAIT, "NEED_WAIT"}, \
+ { EXTENT_DAMAGED, "DAMAGED"}, \
+ { EXTENT_NORESERVE, "NORESERVE"}, \
+ { EXTENT_QGROUP_RESERVED, "QGROUP_RESERVED"}, \
+ { EXTENT_CLEAR_DATA_RESV, "CLEAR_DATA_RESV"}, \
+ { EXTENT_DELALLOC_NEW, "DELALLOC_NEW"}
+
#define BTRFS_FSID_SIZE 16
#define TP_STRUCT__entry_fsid __array(u8, fsid, BTRFS_FSID_SIZE)
#define TP_fast_assign_fsid(fs_info) \
- memcpy(__entry->fsid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE)
+({ \
+ if (fs_info) \
+ memcpy(__entry->fsid, fs_info->fs_devices->fsid, \
+ BTRFS_FSID_SIZE); \
+ else \
+ memset(__entry->fsid, 0, BTRFS_FSID_SIZE); \
+})
#define TP_STRUCT__entry_btrfs(args...) \
TP_STRUCT__entry( \
@@ -1878,6 +1915,126 @@ DEFINE_EVENT(btrfs__block_group, btrfs_skip_unused_block_group,
TP_ARGS(bg_cache)
);
+TRACE_EVENT(btrfs_set_extent_bit,
+ TP_PROTO(const struct extent_io_tree *tree,
+ u64 start, u64 len, unsigned set_bits),
+
+ TP_ARGS(tree, start, len, set_bits),
+
+ TP_STRUCT__entry_btrfs(
+ __field( unsigned, owner )
+ __field( u64, ino )
+ __field( u64, rootid )
+ __field( u64, start )
+ __field( u64, len )
+ __field( unsigned, set_bits)
+ ),
+
+ TP_fast_assign_btrfs(tree->fs_info,
+ __entry->owner = tree->owner;
+ if (tree->private_data) {
+ struct inode *inode = tree->private_data;
+
+ __entry->ino = btrfs_ino(BTRFS_I(inode));
+ __entry->rootid =
+ BTRFS_I(inode)->root->root_key.objectid;
+ } else {
+ __entry->ino = 0;
+ __entry->rootid = 0;
+ }
+ __entry->start = start;
+ __entry->len = len;
+ __entry->set_bits = set_bits;
+ ),
+
+ TP_printk_btrfs(
+"io_tree=%s ino=%llu root=%llu start=%llu len=%llu set_bits=%s",
+ show_extent_io_tree_owner(__entry->owner), __entry->ino,
+ __entry->rootid, __entry->start, __entry->len,
+ __print_flags(__entry->set_bits, "|", EXTENT_FLAGS))
+);
+
+TRACE_EVENT(btrfs_clear_extent_bit,
+ TP_PROTO(const struct extent_io_tree *tree,
+ u64 start, u64 len, unsigned clear_bits),
+
+ TP_ARGS(tree, start, len, clear_bits),
+
+ TP_STRUCT__entry_btrfs(
+ __field( unsigned, owner )
+ __field( u64, ino )
+ __field( u64, rootid )
+ __field( u64, start )
+ __field( u64, len )
+ __field( unsigned, clear_bits)
+ ),
+
+ TP_fast_assign_btrfs(tree->fs_info,
+ __entry->owner = tree->owner;
+ if (tree->private_data) {
+ struct inode *inode = tree->private_data;
+
+ __entry->ino = btrfs_ino(BTRFS_I(inode));
+ __entry->rootid =
+ BTRFS_I(inode)->root->root_key.objectid;
+ } else {
+ __entry->ino = 0;
+ __entry->rootid = 0;
+ }
+ __entry->start = start;
+ __entry->len = len;
+ __entry->clear_bits = clear_bits;
+ ),
+
+ TP_printk_btrfs(
+"io_tree=%s ino=%llu root=%llu start=%llu len=%llu clear_bits=%s",
+ show_extent_io_tree_owner(__entry->owner), __entry->ino,
+ __entry->rootid, __entry->start, __entry->len,
+ __print_flags(__entry->clear_bits, "|", EXTENT_FLAGS))
+);
+
+TRACE_EVENT(btrfs_convert_extent_bit,
+ TP_PROTO(const struct extent_io_tree *tree,
+ u64 start, u64 len, unsigned set_bits, unsigned clear_bits),
+
+ TP_ARGS(tree, start, len, set_bits, clear_bits),
+
+ TP_STRUCT__entry_btrfs(
+ __field( unsigned, owner )
+ __field( u64, ino )
+ __field( u64, rootid )
+ __field( u64, start )
+ __field( u64, len )
+ __field( unsigned, set_bits)
+ __field( unsigned, clear_bits)
+ ),
+
+ TP_fast_assign_btrfs(tree->fs_info,
+ __entry->owner = tree->owner;
+ if (tree->private_data) {
+ struct inode *inode = tree->private_data;
+
+ __entry->ino = btrfs_ino(BTRFS_I(inode));
+ __entry->rootid =
+ BTRFS_I(inode)->root->root_key.objectid;
+ } else {
+ __entry->ino = 0;
+ __entry->rootid = 0;
+ }
+ __entry->start = start;
+ __entry->len = len;
+ __entry->set_bits = set_bits;
+ __entry->clear_bits = clear_bits;
+ ),
+
+ TP_printk_btrfs(
+"io_tree=%s ino=%llu root=%llu start=%llu len=%llu set_bits=%s clear_bits=%s",
+ show_extent_io_tree_owner(__entry->owner), __entry->ino,
+ __entry->rootid, __entry->start, __entry->len,
+ __print_flags(__entry->set_bits , "|", EXTENT_FLAGS),
+ __print_flags(__entry->clear_bits, "|", EXTENT_FLAGS))
+);
+
#endif /* _TRACE_BTRFS_H */
/* This part must be outside protection */
--
2.21.0
