From 4b9bb25b36baa3e2e42b91e451bcd3acfe197a1d Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 1 Aug 2017 12:34:44 -0400 Subject: [PATCH] NFS: Switch to using mapping->private_lock for page writeback lookups. Switch from using the inode->i_lock for this to avoid contention with other metadata manipulation. Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 12479c25028e..866702823869 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -172,18 +172,18 @@ nfs_page_private_request(struct page *page) static struct nfs_page * nfs_page_find_private_request(struct page *page) { - struct inode *inode = page_file_mapping(page)->host; + struct address_space *mapping = page_file_mapping(page); struct nfs_page *req; if (!PagePrivate(page)) return NULL; - spin_lock(&inode->i_lock); + spin_lock(&mapping->private_lock); req = nfs_page_private_request(page); if (req) { WARN_ON_ONCE(req->wb_head != req); kref_get(&req->wb_kref); } - spin_unlock(&inode->i_lock); + spin_unlock(&mapping->private_lock); return req; } @@ -743,6 +743,7 @@ out_err: */ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) { + struct address_space *mapping = page_file_mapping(req->wb_page); struct nfs_inode *nfsi = NFS_I(inode); WARN_ON_ONCE(req->wb_this_page != req); @@ -750,19 +751,23 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) /* Lock the request! */ nfs_lock_request(req); - spin_lock(&inode->i_lock); - if (!nfs_have_writebacks(inode) && - NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) - inode->i_version++; /* * Swap-space should not get truncated. Hence no need to plug the race * with invalidate/truncate. */ + spin_lock(&mapping->private_lock); + if (!nfs_have_writebacks(inode) && + NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) { + spin_lock(&inode->i_lock); + inode->i_version++; + spin_unlock(&inode->i_lock); + } if (likely(!PageSwapCache(req->wb_page))) { set_bit(PG_MAPPED, &req->wb_flags); SetPagePrivate(req->wb_page); set_page_private(req->wb_page, (unsigned long)req); } + spin_unlock(&mapping->private_lock); atomic_long_inc(&nfsi->nrequests); /* this a head request for a page group - mark it as having an * extra reference so sub groups can follow suit. @@ -770,7 +775,6 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) * adding subrequests. */ WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags)); kref_get(&req->wb_kref); - spin_unlock(&inode->i_lock); } /* @@ -778,7 +782,8 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) */ static void nfs_inode_remove_request(struct nfs_page *req) { - struct inode *inode = d_inode(req->wb_context->dentry); + struct address_space *mapping = page_file_mapping(req->wb_page); + struct inode *inode = mapping->host; struct nfs_inode *nfsi = NFS_I(inode); struct nfs_page *head; @@ -786,13 +791,13 @@ static void nfs_inode_remove_request(struct nfs_page *req) if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) { head = req->wb_head; - spin_lock(&inode->i_lock); + spin_lock(&mapping->private_lock); if (likely(head->wb_page && !PageSwapCache(head->wb_page))) { set_page_private(head->wb_page, 0); ClearPagePrivate(head->wb_page); clear_bit(PG_MAPPED, &head->wb_flags); } - spin_unlock(&inode->i_lock); + spin_unlock(&mapping->private_lock); } if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) -- 2.30.2