From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: [PATCH 3/8] dax: expose __dax_fault for filesystems with locking constraints Date: Tue, 24 Mar 2015 21:51:01 +1100 Message-ID: <1427194266-2885-4-git-send-email-david@fromorbit.com> References: <1427194266-2885-1-git-send-email-david@fromorbit.com> Cc: linux-fsdevel@vger.kernel.org, willy@linux.intel.com, jack@suse.cz To: xfs@oss.sgi.com Return-path: Received: from ipmail04.adl6.internode.on.net ([150.101.137.141]:20051 "EHLO ipmail04.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752412AbbCXKvU (ORCPT ); Tue, 24 Mar 2015 06:51:20 -0400 In-Reply-To: <1427194266-2885-1-git-send-email-david@fromorbit.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Dave Chinner Some filesystems cannot call dax_fault() directly because they have different locking and/or allocation constraints in the page fault IO path. To handle this, we need to follow the same model as the generic block_page_mkwrite code, where the internals are exposed via __block_page_mkwrite() so that filesystems can wrap the correct locking and operations around the outside. This is loosely based on a patch originally from Matthew Willcox. Unlike the original patch, it does not change ext4 code, error returns or unwritten extent conversion handling. It also adds a __dax_mkwrite() wrapper for .page_mkwrite implementations to do the right thing, too. Signed-off-by: Dave Chinner --- fs/dax.c | 15 +++++++++++++-- include/linux/fs.h | 5 ++++- 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 431ec2b..0121f7d 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -313,7 +313,17 @@ static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh, return error; } -static int do_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, +/** + * __dax_fault - handle a page fault on a DAX file + * @vma: The virtual memory area where the fault occurred + * @vmf: The description of the fault + * @get_block: The filesystem method used to translate file offsets to blocks + * + * When a page fault occurs, filesystems may call this helper in their + * fault handler for DAX files. __dax_fault() assumes the caller has done all + * the necessary locking for the page fault to proceed successfully. + */ +int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, get_block_t get_block, dax_iodone_t complete_unwritten) { struct file *file = vma->vm_file; @@ -440,6 +450,7 @@ static int do_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, } goto out; } +EXPORT_SYMBOL(__dax_fault); /** * dax_fault - handle a page fault on a DAX file @@ -460,7 +471,7 @@ int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, sb_start_pagefault(sb); file_update_time(vma->vm_file); } - result = do_dax_fault(vma, vmf, get_block, complete_unwritten); + result = __dax_fault(vma, vmf, get_block, complete_unwritten); if (vmf->flags & FAULT_FLAG_WRITE) sb_end_pagefault(sb); diff --git a/include/linux/fs.h b/include/linux/fs.h index 82100ae..7e5a2d6 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2606,7 +2606,10 @@ 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, dax_iodone_t); -#define dax_mkwrite(vma, vmf, gb, iod) dax_fault(vma, vmf, gb, iod) +int __dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t, + dax_iodone_t); +#define dax_mkwrite(vma, vmf, gb, iod) dax_fault(vma, vmf, gb, iod) +#define __dax_mkwrite(vma, vmf, gb, iod) __dax_fault(vma, vmf, gb, iod) #ifdef CONFIG_BLOCK typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode, -- 2.0.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 7B3637F54 for ; Tue, 24 Mar 2015 05:51:23 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay1.corp.sgi.com (Postfix) with ESMTP id 58CB88F8050 for ; Tue, 24 Mar 2015 03:51:23 -0700 (PDT) Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net [150.101.137.141]) by cuda.sgi.com with ESMTP id q2BgAnJtQHuceX3j for ; Tue, 24 Mar 2015 03:51:21 -0700 (PDT) From: Dave Chinner Subject: [PATCH 3/8] dax: expose __dax_fault for filesystems with locking constraints Date: Tue, 24 Mar 2015 21:51:01 +1100 Message-Id: <1427194266-2885-4-git-send-email-david@fromorbit.com> In-Reply-To: <1427194266-2885-1-git-send-email-david@fromorbit.com> References: <1427194266-2885-1-git-send-email-david@fromorbit.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Cc: linux-fsdevel@vger.kernel.org, willy@linux.intel.com, jack@suse.cz From: Dave Chinner Some filesystems cannot call dax_fault() directly because they have different locking and/or allocation constraints in the page fault IO path. To handle this, we need to follow the same model as the generic block_page_mkwrite code, where the internals are exposed via __block_page_mkwrite() so that filesystems can wrap the correct locking and operations around the outside. This is loosely based on a patch originally from Matthew Willcox. Unlike the original patch, it does not change ext4 code, error returns or unwritten extent conversion handling. It also adds a __dax_mkwrite() wrapper for .page_mkwrite implementations to do the right thing, too. Signed-off-by: Dave Chinner --- fs/dax.c | 15 +++++++++++++-- include/linux/fs.h | 5 ++++- 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 431ec2b..0121f7d 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -313,7 +313,17 @@ static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh, return error; } -static int do_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, +/** + * __dax_fault - handle a page fault on a DAX file + * @vma: The virtual memory area where the fault occurred + * @vmf: The description of the fault + * @get_block: The filesystem method used to translate file offsets to blocks + * + * When a page fault occurs, filesystems may call this helper in their + * fault handler for DAX files. __dax_fault() assumes the caller has done all + * the necessary locking for the page fault to proceed successfully. + */ +int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, get_block_t get_block, dax_iodone_t complete_unwritten) { struct file *file = vma->vm_file; @@ -440,6 +450,7 @@ static int do_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, } goto out; } +EXPORT_SYMBOL(__dax_fault); /** * dax_fault - handle a page fault on a DAX file @@ -460,7 +471,7 @@ int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, sb_start_pagefault(sb); file_update_time(vma->vm_file); } - result = do_dax_fault(vma, vmf, get_block, complete_unwritten); + result = __dax_fault(vma, vmf, get_block, complete_unwritten); if (vmf->flags & FAULT_FLAG_WRITE) sb_end_pagefault(sb); diff --git a/include/linux/fs.h b/include/linux/fs.h index 82100ae..7e5a2d6 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2606,7 +2606,10 @@ 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, dax_iodone_t); -#define dax_mkwrite(vma, vmf, gb, iod) dax_fault(vma, vmf, gb, iod) +int __dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t, + dax_iodone_t); +#define dax_mkwrite(vma, vmf, gb, iod) dax_fault(vma, vmf, gb, iod) +#define __dax_mkwrite(vma, vmf, gb, iod) __dax_fault(vma, vmf, gb, iod) #ifdef CONFIG_BLOCK typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode, -- 2.0.0 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs