From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f180.google.com (mail-wi0-f180.google.com [209.85.212.180]) by kanga.kvack.org (Postfix) with ESMTP id 755B16B006E for ; Tue, 7 Apr 2015 04:43:55 -0400 (EDT) Received: by widjs5 with SMTP id js5so5530319wid.1 for ; Tue, 07 Apr 2015 01:43:55 -0700 (PDT) Received: from mail-wi0-f181.google.com (mail-wi0-f181.google.com. [209.85.212.181]) by mx.google.com with ESMTPS id pd5si11578994wjb.93.2015.04.07.01.43.53 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 07 Apr 2015 01:43:54 -0700 (PDT) Received: by wizk4 with SMTP id k4so8666042wiz.1 for ; Tue, 07 Apr 2015 01:43:53 -0700 (PDT) Message-ID: <552398C6.1010304@plexistor.com> Date: Tue, 07 Apr 2015 11:43:50 +0300 From: Boaz Harrosh MIME-Version: 1.0 Subject: [PATCH 2/3] dax: use pfn_mkwrite to update c/mtime + freeze protection References: <55239645.9000507@plexistor.com> In-Reply-To: <55239645.9000507@plexistor.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Chinner , Matthew Wilcox , Andrew Morton , "Kirill A. Shutemov" , Jan Kara , Hugh Dickins , Mel Gorman , linux-mm@kvack.org, linux-nvdimm , linux-fsdevel , Eryu Guan , Christoph Hellwig Cc: Stable Tree From: Yigal Korman [v1] Without this patch, c/mtime is not updated correctly when mmap'ed page is first read from and then written to. A new xfstest is submitted for testing this (generic/080) [v2] Jan Kara has pointed out that if we add the sb_start/end_pagefault pair in the new pfn_mkwrite we are then fixing another bug where: A user could start writing to the page while filesystem is frozen. CC: Jan Kara CC: Matthew Wilcox CC: Dave Chinner CC: Stable Tree Signed-off-by: Yigal Korman Signed-off-by: Boaz Harrosh --- fs/dax.c | 17 +++++++++++++++++ fs/ext2/file.c | 1 + fs/ext4/file.c | 1 + include/linux/fs.h | 1 + 4 files changed, 20 insertions(+) diff --git a/fs/dax.c b/fs/dax.c index ed1619e..d0bd1f4 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -464,6 +464,23 @@ int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, EXPORT_SYMBOL_GPL(dax_fault); /** + * dax_pfn_mkwrite - handle first write to DAX page + * @vma: The virtual memory area where the fault occurred + * @vmf: The description of the fault + * + */ +int dax_pfn_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct super_block *sb = file_inode(vma->vm_file)->i_sb; + + sb_start_pagefault(sb); + file_update_time(vma->vm_file); + sb_end_pagefault(sb); + return VM_FAULT_NOPAGE; +} +EXPORT_SYMBOL_GPL(dax_pfn_mkwrite); + +/** * dax_zero_page_range - zero a range within a page of a DAX file * @inode: The file being truncated * @from: The file offset that is being truncated to diff --git a/fs/ext2/file.c b/fs/ext2/file.c index e317017..866a3ce 100644 --- a/fs/ext2/file.c +++ b/fs/ext2/file.c @@ -39,6 +39,7 @@ static int ext2_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) static const struct vm_operations_struct ext2_dax_vm_ops = { .fault = ext2_dax_fault, .page_mkwrite = ext2_dax_mkwrite, + .pfn_mkwrite = dax_pfn_mkwrite, }; static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 598abbb..aa78c70 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -206,6 +206,7 @@ static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) static const struct vm_operations_struct ext4_dax_vm_ops = { .fault = ext4_dax_fault, .page_mkwrite = ext4_dax_mkwrite, + .pfn_mkwrite = dax_pfn_mkwrite, }; #else #define ext4_dax_vm_ops ext4_file_vm_ops diff --git a/include/linux/fs.h b/include/linux/fs.h index 368e349..394035f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2628,6 +2628,7 @@ int dax_clear_blocks(struct inode *, sector_t block, long size); int dax_zero_page_range(struct inode *, loff_t from, unsigned len, get_block_t); int dax_truncate_page(struct inode *, loff_t from, get_block_t); int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t); +int dax_pfn_mkwrite(struct vm_area_struct *, struct vm_fault *); #define dax_mkwrite(vma, vmf, gb) dax_fault(vma, vmf, gb) #ifdef CONFIG_BLOCK -- 1.9.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org