Return-Path: Received: from mail-it0-f68.google.com ([209.85.214.68]:34647 "EHLO mail-it0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751953AbdHCNqC (ORCPT ); Thu, 3 Aug 2017 09:46:02 -0400 Received: by mail-it0-f68.google.com with SMTP id t78so1321164ita.1 for ; Thu, 03 Aug 2017 06:46:01 -0700 (PDT) From: Trond Myklebust To: Chuck Lever , linux-nfs@vger.kernel.org Subject: [PATCH v2 22/28] NFS: Use an atomic_long_t to count the number of requests Date: Thu, 3 Aug 2017 09:45:17 -0400 Message-Id: <20170803134523.4922-23-trond.myklebust@primarydata.com> In-Reply-To: <20170803134523.4922-22-trond.myklebust@primarydata.com> References: <20170803134523.4922-1-trond.myklebust@primarydata.com> <20170803134523.4922-2-trond.myklebust@primarydata.com> <20170803134523.4922-3-trond.myklebust@primarydata.com> <20170803134523.4922-4-trond.myklebust@primarydata.com> <20170803134523.4922-5-trond.myklebust@primarydata.com> <20170803134523.4922-6-trond.myklebust@primarydata.com> <20170803134523.4922-7-trond.myklebust@primarydata.com> <20170803134523.4922-8-trond.myklebust@primarydata.com> <20170803134523.4922-9-trond.myklebust@primarydata.com> <20170803134523.4922-10-trond.myklebust@primarydata.com> <20170803134523.4922-11-trond.myklebust@primarydata.com> <20170803134523.4922-12-trond.myklebust@primarydata.com> <20170803134523.4922-13-trond.myklebust@primarydata.com> <20170803134523.4922-14-trond.myklebust@primarydata.com> <20170803134523.4922-15-trond.myklebust@primarydata.com> <20170803134523.4922-16-trond.myklebust@primarydata.com> <20170803134523.4922-17-trond.myklebust@primarydata.com> <20170803134523.4922-18-trond.myklebust@primarydata.com> <20170803134523.4922-19-trond.myklebust@primarydata.com> <20170803134523.4922-20-trond.myklebust@primarydata.com> <20170803134523.4922-21-trond.myklebust@primarydata.com> <20170803134523.4922-22-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Rather than forcing us to take the inode->i_lock just in order to bump the number. Signed-off-by: Trond Myklebust --- fs/nfs/callback_proc.c | 2 +- fs/nfs/delegation.c | 2 +- fs/nfs/inode.c | 7 +++---- fs/nfs/pagelist.c | 4 +--- fs/nfs/write.c | 18 +++++------------- include/linux/nfs_fs.h | 4 ++-- 6 files changed, 13 insertions(+), 24 deletions(-) diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index 5427cdf04c5a..14358de173fb 100644 --- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -51,7 +51,7 @@ __be32 nfs4_callback_getattr(void *argp, void *resp, goto out_iput; res->size = i_size_read(inode); res->change_attr = delegation->change_attr; - if (nfsi->nrequests != 0) + if (nfs_have_writebacks(inode)) res->change_attr++; res->ctime = inode->i_ctime; res->mtime = inode->i_mtime; diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index d7df5e67b0c1..606dd3871f66 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -1089,7 +1089,7 @@ bool nfs4_delegation_flush_on_close(const struct inode *inode) delegation = rcu_dereference(nfsi->delegation); if (delegation == NULL || !(delegation->type & FMODE_WRITE)) goto out; - if (nfsi->nrequests < delegation->pagemod_limit) + if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit) ret = false; out: rcu_read_unlock(); diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 34d9ebbc0dfd..0480eb02299a 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1285,7 +1285,6 @@ static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi) static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr) { - struct nfs_inode *nfsi = NFS_I(inode); unsigned long ret = 0; if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE) @@ -1315,7 +1314,7 @@ static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE) && (fattr->valid & NFS_ATTR_FATTR_SIZE) && i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size) - && nfsi->nrequests == 0) { + && !nfs_have_writebacks(inode)) { i_size_write(inode, nfs_size_to_loff_t(fattr->size)); ret |= NFS_INO_INVALID_ATTR; } @@ -1823,7 +1822,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) if (new_isize != cur_isize) { /* Do we perhaps have any outstanding writes, or has * the file grown beyond our last write? */ - if (nfsi->nrequests == 0 || new_isize > cur_isize) { + if (!nfs_have_writebacks(inode) || new_isize > cur_isize) { i_size_write(inode, new_isize); if (!have_writers) invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA; @@ -2012,7 +2011,7 @@ static void init_once(void *foo) INIT_LIST_HEAD(&nfsi->access_cache_entry_lru); INIT_LIST_HEAD(&nfsi->access_cache_inode_lru); INIT_LIST_HEAD(&nfsi->commit_info.list); - nfsi->nrequests = 0; + atomic_long_set(&nfsi->nrequests, 0); nfsi->commit_info.ncommit = 0; atomic_set(&nfsi->commit_info.rpcs_out, 0); init_rwsem(&nfsi->rmdir_sem); diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index af6731dd4324..ec97c301899b 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -258,9 +258,7 @@ nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev) inode = page_file_mapping(req->wb_page)->host; set_bit(PG_INODE_REF, &req->wb_flags); kref_get(&req->wb_kref); - spin_lock(&inode->i_lock); - NFS_I(inode)->nrequests++; - spin_unlock(&inode->i_lock); + atomic_long_inc(&NFS_I(inode)->nrequests); } } } diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 5ab5ca24b48a..08093552f115 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -434,9 +434,7 @@ nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list, if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags)) { nfs_release_request(subreq); - spin_lock(&inode->i_lock); - NFS_I(inode)->nrequests--; - spin_unlock(&inode->i_lock); + atomic_long_dec(&NFS_I(inode)->nrequests); } /* subreq is now totally disconnected from page group or any @@ -567,9 +565,7 @@ nfs_lock_and_join_requests(struct page *page) if (test_and_clear_bit(PG_REMOVE, &head->wb_flags)) { set_bit(PG_INODE_REF, &head->wb_flags); kref_get(&head->wb_kref); - spin_lock(&inode->i_lock); - NFS_I(inode)->nrequests++; - spin_unlock(&inode->i_lock); + atomic_long_inc(&NFS_I(inode)->nrequests); } nfs_page_group_unlock(head); @@ -755,7 +751,7 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) nfs_lock_request(req); spin_lock(&inode->i_lock); - if (!nfsi->nrequests && + if (!nfs_have_writebacks(inode) && NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) inode->i_version++; /* @@ -767,7 +763,7 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) SetPagePrivate(req->wb_page); set_page_private(req->wb_page, (unsigned long)req); } - nfsi->nrequests++; + 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. * This flag also informs pgio layer when to bump nrequests when @@ -786,6 +782,7 @@ static void nfs_inode_remove_request(struct nfs_page *req) struct nfs_inode *nfsi = NFS_I(inode); struct nfs_page *head; + atomic_long_dec(&nfsi->nrequests); if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) { head = req->wb_head; @@ -795,11 +792,6 @@ static void nfs_inode_remove_request(struct nfs_page *req) ClearPagePrivate(head->wb_page); clear_bit(PG_MAPPED, &head->wb_flags); } - nfsi->nrequests--; - spin_unlock(&inode->i_lock); - } else { - spin_lock(&inode->i_lock); - nfsi->nrequests--; spin_unlock(&inode->i_lock); } diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 121a702888b4..238fdc4c46df 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -154,7 +154,7 @@ struct nfs_inode { */ __be32 cookieverf[2]; - unsigned long nrequests; + atomic_long_t nrequests; struct nfs_mds_commit_info commit_info; /* Open contexts for shared mmap writes */ @@ -511,7 +511,7 @@ extern void nfs_commit_free(struct nfs_commit_data *data); static inline int nfs_have_writebacks(struct inode *inode) { - return NFS_I(inode)->nrequests != 0; + return atomic_long_read(&NFS_I(inode)->nrequests) != 0; } /* -- 2.13.3