From f62f12b3a426c8f65b10011b1ec40ba4277cbf5f Mon Sep 17 00:00:00 2001 From: Junxiao Bi Date: Thu, 18 Dec 2014 16:17:32 -0800 Subject: [PATCH] ocfs2: reflink: fix slow unlink for refcounted file When running ocfs2 test suite multiple nodes reflink stress test, for a 4 nodes cluster, every unlink() for refcounted file needs about 700s. The slow unlink is caused by the contention of refcount tree lock since all nodes are unlink files using the same refcount tree. When the unlinking file have many extents(over 1600 in our test), most of the extents has refcounted flag set. In ocfs2_commit_truncate(), it will execute the following call trace for every extents. This means it needs get and released refcount tree lock about 1600 times. And when several nodes are do this at the same time, the performance will be very low. ocfs2_remove_btree_range() -- ocfs2_lock_refcount_tree() ---- ocfs2_refcount_lock() ------ __ocfs2_cluster_lock() ocfs2_refcount_lock() is costly, move it to ocfs2_commit_truncate() to do lock/unlock once can improve a lot performance. Signed-off-by: Junxiao Bi Cc: Wengang Reviewed-by: Mark Fasheh Cc: Joel Becker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/alloc.c | 28 +++++++++++++++++++++------- fs/ocfs2/alloc.h | 2 +- fs/ocfs2/dir.c | 2 +- fs/ocfs2/file.c | 2 +- 4 files changed, 24 insertions(+), 10 deletions(-) diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c index a93bf9892256..fcae9ef1a328 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -5662,7 +5662,7 @@ int ocfs2_remove_btree_range(struct inode *inode, struct ocfs2_extent_tree *et, u32 cpos, u32 phys_cpos, u32 len, int flags, struct ocfs2_cached_dealloc_ctxt *dealloc, - u64 refcount_loc) + u64 refcount_loc, bool refcount_tree_locked) { int ret, credits = 0, extra_blocks = 0; u64 phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos); @@ -5676,11 +5676,13 @@ int ocfs2_remove_btree_range(struct inode *inode, BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL)); - ret = ocfs2_lock_refcount_tree(osb, refcount_loc, 1, - &ref_tree, NULL); - if (ret) { - mlog_errno(ret); - goto bail; + if (!refcount_tree_locked) { + ret = ocfs2_lock_refcount_tree(osb, refcount_loc, 1, + &ref_tree, NULL); + if (ret) { + mlog_errno(ret); + goto bail; + } } ret = ocfs2_prepare_refcount_change_for_del(inode, @@ -7021,6 +7023,7 @@ int ocfs2_commit_truncate(struct ocfs2_super *osb, u64 refcount_loc = le64_to_cpu(di->i_refcount_loc); struct ocfs2_extent_tree et; struct ocfs2_cached_dealloc_ctxt dealloc; + struct ocfs2_refcount_tree *ref_tree = NULL; ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh); ocfs2_init_dealloc_ctxt(&dealloc); @@ -7130,9 +7133,18 @@ int ocfs2_commit_truncate(struct ocfs2_super *osb, phys_cpos = ocfs2_blocks_to_clusters(inode->i_sb, blkno); + if ((flags & OCFS2_EXT_REFCOUNTED) && trunc_len && !ref_tree) { + status = ocfs2_lock_refcount_tree(osb, refcount_loc, 1, + &ref_tree, NULL); + if (status) { + mlog_errno(status); + goto bail; + } + } + status = ocfs2_remove_btree_range(inode, &et, trunc_cpos, phys_cpos, trunc_len, flags, &dealloc, - refcount_loc); + refcount_loc, true); if (status < 0) { mlog_errno(status); goto bail; @@ -7147,6 +7159,8 @@ int ocfs2_commit_truncate(struct ocfs2_super *osb, goto start; bail: + if (ref_tree) + ocfs2_unlock_refcount_tree(osb, ref_tree, 1); ocfs2_schedule_truncate_log_flush(osb, 1); diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h index ca381c584127..fb09b97db162 100644 --- a/fs/ocfs2/alloc.h +++ b/fs/ocfs2/alloc.h @@ -142,7 +142,7 @@ int ocfs2_remove_btree_range(struct inode *inode, struct ocfs2_extent_tree *et, u32 cpos, u32 phys_cpos, u32 len, int flags, struct ocfs2_cached_dealloc_ctxt *dealloc, - u64 refcount_loc); + u64 refcount_loc, bool refcount_tree_locked); int ocfs2_num_free_extents(struct ocfs2_super *osb, struct ocfs2_extent_tree *et); diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c index 79d56dc981bc..319e786175af 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -4479,7 +4479,7 @@ int ocfs2_dx_dir_truncate(struct inode *dir, struct buffer_head *di_bh) p_cpos = ocfs2_blocks_to_clusters(dir->i_sb, blkno); ret = ocfs2_remove_btree_range(dir, &et, cpos, p_cpos, clen, 0, - &dealloc, 0); + &dealloc, 0, false); if (ret) { mlog_errno(ret); goto out; diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 69fb9f75b082..3950693dd0f6 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -1803,7 +1803,7 @@ static int ocfs2_remove_inode_range(struct inode *inode, ret = ocfs2_remove_btree_range(inode, &et, trunc_cpos, phys_cpos, trunc_len, flags, - &dealloc, refcount_loc); + &dealloc, refcount_loc, false); if (ret < 0) { mlog_errno(ret); goto out;