Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ie0-f172.google.com ([209.85.223.172]:62717 "EHLO mail-ie0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754113AbaGKOUz (ORCPT ); Fri, 11 Jul 2014 10:20:55 -0400 Received: by mail-ie0-f172.google.com with SMTP id rd18so936735iec.31 for ; Fri, 11 Jul 2014 07:20:55 -0700 (PDT) From: Weston Andros Adamson To: trond.myklebust@primarydata.com Cc: linux-nfs@vger.kernel.org, Weston Andros Adamson Subject: [PATCH 3/5] nfs: change find_request to find_head_request Date: Fri, 11 Jul 2014 10:20:47 -0400 Message-Id: <1405088449-11268-4-git-send-email-dros@primarydata.com> In-Reply-To: <1405088449-11268-1-git-send-email-dros@primarydata.com> References: <1405088449-11268-1-git-send-email-dros@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: nfs_page_find_request_locked* should find the head request for that page. Rename the functions and add comments to make this clear, and fix a bug that could return a subrequest when page_private isn't set on the page. Signed-off-by: Weston Andros Adamson --- fs/nfs/write.c | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 827b57b..2e2b9f1 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -91,8 +91,15 @@ static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error) set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); } +/* + * nfs_page_find_head_request_locked - find head request associated with @page + * + * must be called while holding the inode lock. + * + * returns matching head request with reference held, or NULL if not found. + */ static struct nfs_page * -nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page) +nfs_page_find_head_request_locked(struct nfs_inode *nfsi, struct page *page) { struct nfs_page *req = NULL; @@ -104,25 +111,33 @@ nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page) /* Linearly search the commit list for the correct req */ list_for_each_entry_safe(freq, t, &nfsi->commit_info.list, wb_list) { if (freq->wb_page == page) { - req = freq; + req = freq->wb_head; break; } } } - if (req) + if (req) { + WARN_ON_ONCE(req->wb_head != req); + kref_get(&req->wb_kref); + } return req; } -static struct nfs_page *nfs_page_find_request(struct page *page) +/* + * nfs_page_find_head_request - find head request associated with @page + * + * returns matching head request with reference held, or NULL if not found. + */ +static struct nfs_page *nfs_page_find_head_request(struct page *page) { struct inode *inode = page_file_mapping(page)->host; struct nfs_page *req = NULL; spin_lock(&inode->i_lock); - req = nfs_page_find_request_locked(NFS_I(inode), page); + req = nfs_page_find_head_request_locked(NFS_I(inode), page); spin_unlock(&inode->i_lock); return req; } @@ -282,7 +297,7 @@ static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblo spin_lock(&inode->i_lock); for (;;) { - req = nfs_page_find_request_locked(NFS_I(inode), page); + req = nfs_page_find_head_request_locked(NFS_I(inode), page); if (req == NULL) break; if (nfs_lock_request(req)) @@ -767,7 +782,7 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode, spin_lock(&inode->i_lock); for (;;) { - req = nfs_page_find_request_locked(NFS_I(inode), page); + req = nfs_page_find_head_request_locked(NFS_I(inode), page); if (req == NULL) goto out_unlock; @@ -875,7 +890,7 @@ int nfs_flush_incompatible(struct file *file, struct page *page) * dropped page. */ do { - req = nfs_page_find_request(page); + req = nfs_page_find_head_request(page); if (req == NULL) return 0; l_ctx = req->wb_lock_context; @@ -1561,7 +1576,7 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page) for (;;) { wait_on_page_writeback(page); - req = nfs_page_find_request(page); + req = nfs_page_find_head_request(page); if (req == NULL) break; if (nfs_lock_request(req)) { -- 1.8.5.2 (Apple Git-48)