From 1abe9b8a138c9988ba8f7bfded6453649a31541f Mon Sep 17 00:00:00 2001 From: liubo Date: Thu, 24 Mar 2011 11:18:59 +0000 Subject: 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 Signed-off-by: Chris Mason --- fs/btrfs/delayed-ref.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs/btrfs/delayed-ref.c') diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c index e807b143b857..bce28f653899 100644 --- a/fs/btrfs/delayed-ref.c +++ b/fs/btrfs/delayed-ref.c @@ -483,6 +483,8 @@ static noinline int add_delayed_ref_head(struct btrfs_trans_handle *trans, 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 @@ static noinline int add_delayed_tree_ref(struct btrfs_trans_handle *trans, } 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 @@ static noinline int add_delayed_data_ref(struct btrfs_trans_handle *trans, 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) { -- cgit v1.2.2 From f2a97a9dbd86eb1ef956bdf20e05c507b32beb96 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Thu, 5 May 2011 12:44:41 +0200 Subject: btrfs: remove all unused functions Remove static and global declarations and/or definitions. Reduces size of btrfs.ko by ~3.4kB. text data bss dec hex filename 402081 7464 200 409745 64091 btrfs.ko.base 398620 7144 200 405964 631cc btrfs.ko.remove-all Signed-off-by: David Sterba --- fs/btrfs/delayed-ref.c | 38 -------------------------------------- 1 file changed, 38 deletions(-) (limited to 'fs/btrfs/delayed-ref.c') diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c index bce28f653899..cb9b9a431fc9 100644 --- a/fs/btrfs/delayed-ref.c +++ b/fs/btrfs/delayed-ref.c @@ -280,44 +280,6 @@ again: return 1; } -/* - * This checks to see if there are any delayed refs in the - * btree for a given bytenr. It returns one if it finds any - * and zero otherwise. - * - * If it only finds a head node, it returns 0. - * - * The idea is to use this when deciding if you can safely delete an - * extent from the extent allocation tree. There may be a pending - * ref in the rbtree that adds or removes references, so as long as this - * returns one you need to leave the BTRFS_EXTENT_ITEM in the extent - * allocation tree. - */ -int btrfs_delayed_ref_pending(struct btrfs_trans_handle *trans, u64 bytenr) -{ - struct btrfs_delayed_ref_node *ref; - struct btrfs_delayed_ref_root *delayed_refs; - struct rb_node *prev_node; - int ret = 0; - - delayed_refs = &trans->transaction->delayed_refs; - spin_lock(&delayed_refs->lock); - - ref = find_ref_head(&delayed_refs->root, bytenr, NULL); - if (ref) { - prev_node = rb_prev(&ref->rb_node); - if (!prev_node) - goto out; - ref = rb_entry(prev_node, struct btrfs_delayed_ref_node, - rb_node); - if (ref->bytenr == bytenr) - ret = 1; - } -out: - spin_unlock(&delayed_refs->lock); - return ret; -} - /* * helper function to update an extent delayed ref in the * rbtree. existing and update must both have the same -- cgit v1.2.2 From 182608c8294b5fe90d7bbd4b026c82bf0a24b736 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Thu, 5 May 2011 13:13:16 +0200 Subject: btrfs: remove old unused commented out code Remove code which has been #if0-ed out for a very long time and does not seem to be related to current codebase anymore. Signed-off-by: David Sterba --- fs/btrfs/delayed-ref.c | 76 -------------------------------------------------- 1 file changed, 76 deletions(-) (limited to 'fs/btrfs/delayed-ref.c') diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c index cb9b9a431fc9..125cf76fcd08 100644 --- a/fs/btrfs/delayed-ref.c +++ b/fs/btrfs/delayed-ref.c @@ -709,79 +709,3 @@ btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr) return btrfs_delayed_node_to_head(ref); return NULL; } - -/* - * add a delayed ref to the tree. This does all of the accounting required - * to make sure the delayed ref is eventually processed before this - * transaction commits. - * - * The main point of this call is to add and remove a backreference in a single - * shot, taking the lock only once, and only searching for the head node once. - * - * It is the same as doing a ref add and delete in two separate calls. - */ -#if 0 -int btrfs_update_delayed_ref(struct btrfs_trans_handle *trans, - u64 bytenr, u64 num_bytes, u64 orig_parent, - u64 parent, u64 orig_ref_root, u64 ref_root, - u64 orig_ref_generation, u64 ref_generation, - u64 owner_objectid, int pin) -{ - struct btrfs_delayed_ref *ref; - struct btrfs_delayed_ref *old_ref; - struct btrfs_delayed_ref_head *head_ref; - struct btrfs_delayed_ref_root *delayed_refs; - int ret; - - ref = kmalloc(sizeof(*ref), GFP_NOFS); - if (!ref) - return -ENOMEM; - - old_ref = kmalloc(sizeof(*old_ref), GFP_NOFS); - if (!old_ref) { - kfree(ref); - return -ENOMEM; - } - - /* - * the parent = 0 case comes from cases where we don't actually - * know the parent yet. It will get updated later via a add/drop - * pair. - */ - if (parent == 0) - parent = bytenr; - if (orig_parent == 0) - orig_parent = bytenr; - - head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS); - if (!head_ref) { - kfree(ref); - kfree(old_ref); - return -ENOMEM; - } - delayed_refs = &trans->transaction->delayed_refs; - spin_lock(&delayed_refs->lock); - - /* - * insert both the head node and the new ref without dropping - * the spin lock - */ - ret = __btrfs_add_delayed_ref(trans, &head_ref->node, bytenr, num_bytes, - (u64)-1, 0, 0, 0, - BTRFS_UPDATE_DELAYED_HEAD, 0); - BUG_ON(ret); - - ret = __btrfs_add_delayed_ref(trans, &ref->node, bytenr, num_bytes, - parent, ref_root, ref_generation, - owner_objectid, BTRFS_ADD_DELAYED_REF, 0); - BUG_ON(ret); - - ret = __btrfs_add_delayed_ref(trans, &old_ref->node, bytenr, num_bytes, - orig_parent, orig_ref_root, - orig_ref_generation, owner_objectid, - BTRFS_DROP_DELAYED_REF, pin); - BUG_ON(ret); - spin_unlock(&delayed_refs->lock); - return 0; -} -#endif -- cgit v1.2.2