From patchwork Wed Jun 28 22:01:49 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ross Zwisler X-Patchwork-Id: 781949 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3wycKT56bNz9s7g for ; Thu, 29 Jun 2017 08:05:01 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751537AbdF1WD3 (ORCPT ); Wed, 28 Jun 2017 18:03:29 -0400 Received: from mga03.intel.com ([134.134.136.65]:55662 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751541AbdF1WCu (ORCPT ); Wed, 28 Jun 2017 18:02:50 -0400 Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Jun 2017 15:02:48 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,277,1496127600"; d="scan'208";a="279828129" Received: from theros.lm.intel.com ([10.232.112.77]) by fmsmga004.fm.intel.com with ESMTP; 28 Jun 2017 15:02:25 -0700 From: Ross Zwisler To: Andrew Morton , linux-kernel@vger.kernel.org Cc: Ross Zwisler , "Darrick J. Wong" , "Theodore Ts'o" , Alexander Viro , Andreas Dilger , Christoph Hellwig , Dan Williams , Dave Hansen , Ingo Molnar , Jan Kara , Jonathan Corbet , Matthew Wilcox , Steven Rostedt , linux-doc@vger.kernel.org, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@lists.01.org, linux-xfs@vger.kernel.org Subject: [PATCH v3 2/5] dax: relocate some dax functions Date: Wed, 28 Jun 2017 16:01:49 -0600 Message-Id: <20170628220152.28161-3-ross.zwisler@linux.intel.com> X-Mailer: git-send-email 2.9.4 In-Reply-To: <20170628220152.28161-1-ross.zwisler@linux.intel.com> References: <20170628220152.28161-1-ross.zwisler@linux.intel.com> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org dax_load_hole() will soon need to call dax_insert_mapping_entry(), so it needs to be moved lower in dax.c so the definition exists. dax_wake_mapping_entry_waiter() will soon be removed from dax.h and be made static to dax.c, so we need to move its definition above all its callers. Signed-off-by: Ross Zwisler --- fs/dax.c | 138 +++++++++++++++++++++++++++++++-------------------------------- 1 file changed, 69 insertions(+), 69 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 9187f3b..e850837 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -122,6 +122,31 @@ static int wake_exceptional_entry_func(wait_queue_t *wait, unsigned int mode, } /* + * We do not necessarily hold the mapping->tree_lock when we call this + * function so it is possible that 'entry' is no longer a valid item in the + * radix tree. This is okay because all we really need to do is to find the + * correct waitqueue where tasks might be waiting for that old 'entry' and + * wake them. + */ +void dax_wake_mapping_entry_waiter(struct address_space *mapping, + pgoff_t index, void *entry, bool wake_all) +{ + struct exceptional_entry_key key; + wait_queue_head_t *wq; + + wq = dax_entry_waitqueue(mapping, index, entry, &key); + + /* + * Checking for locked entry and prepare_to_wait_exclusive() happens + * under mapping->tree_lock, ditto for entry handling in our callers. + * So at this point all tasks that could have seen our entry locked + * must be in the waitqueue and the following check will see them. + */ + if (waitqueue_active(wq)) + __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); +} + +/* * Check whether the given slot is locked. The function must be called with * mapping->tree_lock held */ @@ -393,31 +418,6 @@ static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index, return entry; } -/* - * We do not necessarily hold the mapping->tree_lock when we call this - * function so it is possible that 'entry' is no longer a valid item in the - * radix tree. This is okay because all we really need to do is to find the - * correct waitqueue where tasks might be waiting for that old 'entry' and - * wake them. - */ -void dax_wake_mapping_entry_waiter(struct address_space *mapping, - pgoff_t index, void *entry, bool wake_all) -{ - struct exceptional_entry_key key; - wait_queue_head_t *wq; - - wq = dax_entry_waitqueue(mapping, index, entry, &key); - - /* - * Checking for locked entry and prepare_to_wait_exclusive() happens - * under mapping->tree_lock, ditto for entry handling in our callers. - * So at this point all tasks that could have seen our entry locked - * must be in the waitqueue and the following check will see them. - */ - if (waitqueue_active(wq)) - __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); -} - static int __dax_invalidate_mapping_entry(struct address_space *mapping, pgoff_t index, bool trunc) { @@ -469,50 +469,6 @@ int dax_invalidate_mapping_entry_sync(struct address_space *mapping, return __dax_invalidate_mapping_entry(mapping, index, false); } -/* - * The user has performed a load from a hole in the file. Allocating - * a new page in the file would cause excessive storage usage for - * workloads with sparse files. We allocate a page cache page instead. - * We'll kick it out of the page cache if it's ever written to, - * otherwise it will simply fall out of the page cache under memory - * pressure without ever having been dirtied. - */ -static int dax_load_hole(struct address_space *mapping, void **entry, - struct vm_fault *vmf) -{ - struct inode *inode = mapping->host; - struct page *page; - int ret; - - /* Hole page already exists? Return it... */ - if (!radix_tree_exceptional_entry(*entry)) { - page = *entry; - goto finish_fault; - } - - /* This will replace locked radix tree entry with a hole page */ - page = find_or_create_page(mapping, vmf->pgoff, - vmf->gfp_mask | __GFP_ZERO); - if (!page) { - ret = VM_FAULT_OOM; - goto out; - } - -finish_fault: - vmf->page = page; - ret = finish_fault(vmf); - vmf->page = NULL; - *entry = page; - if (!ret) { - /* Grab reference for PTE that is now referencing the page */ - get_page(page); - ret = VM_FAULT_NOPAGE; - } -out: - trace_dax_load_hole(inode, vmf, ret); - return ret; -} - static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev, sector_t sector, size_t size, struct page *to, unsigned long vaddr) @@ -937,6 +893,50 @@ int dax_pfn_mkwrite(struct vm_fault *vmf) } EXPORT_SYMBOL_GPL(dax_pfn_mkwrite); +/* + * The user has performed a load from a hole in the file. Allocating + * a new page in the file would cause excessive storage usage for + * workloads with sparse files. We allocate a page cache page instead. + * We'll kick it out of the page cache if it's ever written to, + * otherwise it will simply fall out of the page cache under memory + * pressure without ever having been dirtied. + */ +static int dax_load_hole(struct address_space *mapping, void **entry, + struct vm_fault *vmf) +{ + struct inode *inode = mapping->host; + struct page *page; + int ret; + + /* Hole page already exists? Return it... */ + if (!radix_tree_exceptional_entry(*entry)) { + page = *entry; + goto finish_fault; + } + + /* This will replace locked radix tree entry with a hole page */ + page = find_or_create_page(mapping, vmf->pgoff, + vmf->gfp_mask | __GFP_ZERO); + if (!page) { + ret = VM_FAULT_OOM; + goto out; + } + +finish_fault: + vmf->page = page; + ret = finish_fault(vmf); + vmf->page = NULL; + *entry = page; + if (!ret) { + /* Grab reference for PTE that is now referencing the page */ + get_page(page); + ret = VM_FAULT_NOPAGE; + } +out: + trace_dax_load_hole(inode, vmf, ret); + return ret; +} + static bool dax_range_is_aligned(struct block_device *bdev, unsigned int offset, unsigned int length) {