Btrfs: add initial tracepoint support for btrfs
Tracepoints can provide insight into why btrfs hits bugs and be greatly
helpful for debugging, e.g
dd-7822 [000] 2121.641088: btrfs_inode_request: root = 5(FS_TREE), gen = 4, ino = 256, blocks = 8, disk_i_size = 0, last_trans = 8, logged_trans = 0
dd-7822 [000] 2121.641100: btrfs_inode_new: root = 5(FS_TREE), gen = 8, ino = 257, blocks = 0, disk_i_size = 0, last_trans = 0, logged_trans = 0
btrfs-transacti-7804 [001] 2146.935420: btrfs_cow_block: root = 2(EXTENT_TREE), refs = 2, orig_buf = 29368320 (orig_level = 0), cow_buf = 29388800 (cow_level = 0)
btrfs-transacti-7804 [001] 2146.935473: btrfs_cow_block: root = 1(ROOT_TREE), refs = 2, orig_buf = 29364224 (orig_level = 0), cow_buf = 29392896 (cow_level = 0)
btrfs-transacti-7804 [001] 2146.972221: btrfs_transaction_commit: root = 1(ROOT_TREE), gen = 8
flush-btrfs-2-7821 [001] 2155.824210: btrfs_chunk_alloc: root = 3(CHUNK_TREE), offset = 1103101952, size = 1073741824, num_stripes = 1, sub_stripes = 0, type = DATA
flush-btrfs-2-7821 [001] 2155.824241: btrfs_cow_block: root = 2(EXTENT_TREE), refs = 2, orig_buf = 29388800 (orig_level = 0), cow_buf = 29396992 (cow_level = 0)
flush-btrfs-2-7821 [001] 2155.824255: btrfs_cow_block: root = 4(DEV_TREE), refs = 2, orig_buf = 29372416 (orig_level = 0), cow_buf = 29401088 (cow_level = 0)
flush-btrfs-2-7821 [000] 2155.824329: btrfs_cow_block: root = 3(CHUNK_TREE), refs = 2, orig_buf = 20971520 (orig_level = 0), cow_buf = 20975616 (cow_level = 0)
btrfs-endio-wri-7800 [001] 2155.898019: btrfs_cow_block: root = 5(FS_TREE), refs = 2, orig_buf = 29384704 (orig_level = 0), cow_buf = 29405184 (cow_level = 0)
btrfs-endio-wri-7800 [001] 2155.898043: btrfs_cow_block: root = 7(CSUM_TREE), refs = 2, orig_buf = 29376512 (orig_level = 0), cow_buf = 29409280 (cow_level = 0)
Here is what I have added:
1) ordere_extent:
btrfs_ordered_extent_add
btrfs_ordered_extent_remove
btrfs_ordered_extent_start
btrfs_ordered_extent_put
These provide critical information to understand how ordered_extents are
updated.
2) extent_map:
btrfs_get_extent
extent_map is used in both read and write cases, and it is useful for tracking
how btrfs specific IO is running.
3) writepage:
__extent_writepage
btrfs_writepage_end_io_hook
Pages are cirtical resourses and produce a lot of corner cases during writeback,
so it is valuable to know how page is written to disk.
4) inode:
btrfs_inode_new
btrfs_inode_request
btrfs_inode_evict
These can show where and when a inode is created, when a inode is evicted.
5) sync:
btrfs_sync_file
btrfs_sync_fs
These show sync arguments.
6) transaction:
btrfs_transaction_commit
In transaction based filesystem, it will be useful to know the generation and
who does commit.
7) back reference and cow:
btrfs_delayed_tree_ref
btrfs_delayed_data_ref
btrfs_delayed_ref_head
btrfs_cow_block
Btrfs natively supports back references, these tracepoints are helpful on
understanding btrfs's COW mechanism.
8) chunk:
btrfs_chunk_alloc
btrfs_chunk_free
Chunk is a link between physical offset and logical offset, and stands for space
infomation in btrfs, and these are helpful on tracing space things.
9) reserved_extent:
btrfs_reserved_extent_alloc
btrfs_reserved_extent_free
These can show how btrfs uses its space.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 8680110..465b5d7 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -535,6 +535,9 @@
ret = __btrfs_cow_block(trans, root, buf, parent,
parent_slot, cow_ret, search_start, 0);
+
+ trace_btrfs_cow_block(root, buf, *cow_ret);
+
return ret;
}
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0ee679b..9d0f591 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -28,6 +28,7 @@
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/kobject.h>
+#include <trace/events/btrfs.h>
#include <asm/kmap_types.h>
#include "extent_io.h"
#include "extent_map.h"
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index e807b14..bce28f6 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -483,6 +483,8 @@
INIT_LIST_HEAD(&head_ref->cluster);
mutex_init(&head_ref->mutex);
+ trace_btrfs_delayed_ref_head(ref, head_ref, action);
+
existing = tree_insert(&delayed_refs->root, &ref->rb_node);
if (existing) {
@@ -537,6 +539,8 @@
}
full_ref->level = level;
+ trace_btrfs_delayed_tree_ref(ref, full_ref, action);
+
existing = tree_insert(&delayed_refs->root, &ref->rb_node);
if (existing) {
@@ -591,6 +595,8 @@
full_ref->objectid = owner;
full_ref->offset = offset;
+ trace_btrfs_delayed_data_ref(ref, full_ref, action);
+
existing = tree_insert(&delayed_refs->root, &ref->rb_node);
if (existing) {
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index cd794c3..86ea471 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5412,6 +5412,8 @@
dump_space_info(sinfo, num_bytes, 1);
}
+ trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset);
+
return ret;
}
@@ -5433,6 +5435,8 @@
update_reserved_bytes(cache, len, 0, 1);
btrfs_put_block_group(cache);
+ trace_btrfs_reserved_extent_free(root, start, len);
+
return ret;
}
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 1bbd26b..77c65a0 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2192,6 +2192,8 @@
else
write_flags = WRITE;
+ trace___extent_writepage(page, inode, wbc);
+
WARN_ON(!PageLocked(page));
pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
if (page->index > end_index ||
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index a85b044..656bc0a 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1205,6 +1205,7 @@
int ret = 0;
struct btrfs_trans_handle *trans;
+ trace_btrfs_sync_file(file, datasync);
/* we wait first, since the writeback may change the inode */
root->log_batch++;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e9813bd7..eaa2714 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1787,6 +1787,8 @@
static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
struct extent_state *state, int uptodate)
{
+ trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
+
ClearPagePrivate2(page);
return btrfs_finish_ordered_io(page->mapping->host, start, end);
}
@@ -3718,6 +3720,8 @@
unsigned long nr;
int ret;
+ trace_btrfs_inode_evict(inode);
+
truncate_inode_pages(&inode->i_data, 0);
if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
root == root->fs_info->tree_root))
@@ -4510,6 +4514,8 @@
return ERR_PTR(-ENOMEM);
if (dir) {
+ trace_btrfs_inode_request(dir);
+
ret = btrfs_set_inode_index(dir, index);
if (ret) {
iput(inode);
@@ -4584,6 +4590,9 @@
insert_inode_hash(inode);
inode_tree_add(inode);
+
+ trace_btrfs_inode_new(inode);
+
return inode;
fail:
if (dir)
@@ -5261,6 +5270,9 @@
}
write_unlock(&em_tree->lock);
out:
+
+ trace_btrfs_get_extent(root, em);
+
if (path)
btrfs_free_path(path);
if (trans) {
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 083a554..a1c9404 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -202,6 +202,8 @@
INIT_LIST_HEAD(&entry->list);
INIT_LIST_HEAD(&entry->root_extent_list);
+ trace_btrfs_ordered_extent_add(inode, entry);
+
spin_lock(&tree->lock);
node = tree_insert(&tree->tree, file_offset,
&entry->rb_node);
@@ -387,6 +389,8 @@
struct list_head *cur;
struct btrfs_ordered_sum *sum;
+ trace_btrfs_ordered_extent_put(entry->inode, entry);
+
if (atomic_dec_and_test(&entry->refs)) {
while (!list_empty(&entry->list)) {
cur = entry->list.next;
@@ -420,6 +424,8 @@
spin_lock(&root->fs_info->ordered_extent_lock);
list_del_init(&entry->root_extent_list);
+ trace_btrfs_ordered_extent_remove(inode, entry);
+
/*
* we have no more ordered extents for this inode and
* no dirty pages. We can safely remove it from the
@@ -585,6 +591,8 @@
u64 start = entry->file_offset;
u64 end = start + entry->len - 1;
+ trace_btrfs_ordered_extent_start(inode, entry);
+
/*
* pages in the range can be dirty, clean or writeback. We
* start IO on any dirty ones so the wait doesn't stall waiting
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index d39a989..2edfc03 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -52,6 +52,9 @@
#include "export.h"
#include "compression.h"
+#define CREATE_TRACE_POINTS
+#include <trace/events/btrfs.h>
+
static const struct super_operations btrfs_super_ops;
static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
@@ -620,6 +623,8 @@
struct btrfs_root *root = btrfs_sb(sb);
int ret;
+ trace_btrfs_sync_fs(wait);
+
if (!wait) {
filemap_flush(root->fs_info->btree_inode->i_mapping);
return 0;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3d73c8d..5b4bc68 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1389,6 +1389,8 @@
put_transaction(cur_trans);
put_transaction(cur_trans);
+ trace_btrfs_transaction_commit(root);
+
mutex_unlock(&root->fs_info->trans_mutex);
if (current->journal_info == trans)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dd13eb8..8ba3c9e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -33,17 +33,6 @@
#include "volumes.h"
#include "async-thread.h"
-struct map_lookup {
- u64 type;
- int io_align;
- int io_width;
- int stripe_len;
- int sector_size;
- int num_stripes;
- int sub_stripes;
- struct btrfs_bio_stripe stripes[];
-};
-
static int init_first_rw_device(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_device *device);
@@ -1923,6 +1912,8 @@
BUG_ON(ret);
+ trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
+
if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
BUG_ON(ret);
@@ -2650,6 +2641,8 @@
*num_bytes = chunk_bytes_by_type(type, calc_size,
map->num_stripes, sub_stripes);
+ trace_btrfs_chunk_alloc(info->chunk_root, map, start, *num_bytes);
+
em = alloc_extent_map(GFP_NOFS);
if (!em) {
ret = -ENOMEM;
@@ -2758,6 +2751,7 @@
item_size);
BUG_ON(ret);
}
+
kfree(chunk);
return 0;
}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 7fb59d4..7b38d06 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -145,6 +145,17 @@
u64 max_avail;
};
+struct map_lookup {
+ u64 type;
+ int io_align;
+ int io_width;
+ int stripe_len;
+ int sector_size;
+ int num_stripes;
+ int sub_stripes;
+ struct btrfs_bio_stripe stripes[];
+};
+
/* Used to sort the devices by max_avail(descending sort) */
int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2);
