Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752904AbaAPB1m (ORCPT ); Wed, 15 Jan 2014 20:27:42 -0500 Received: from mga02.intel.com ([134.134.136.20]:49056 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752569AbaAPBZL (ORCPT ); Wed, 15 Jan 2014 20:25:11 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.95,666,1384329600"; d="scan'208";a="439548602" From: Matthew Wilcox To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-ext4@vger.kernel.org Cc: Matthew Wilcox , Ross Zwisler Subject: [PATCH v5 17/22] xip: Add xip_zero_page_range Date: Wed, 15 Jan 2014 20:24:35 -0500 Message-Id: <022dd796862790207b9734143cc5fe85138bc494.1389779962.git.matthew.r.wilcox@intel.com> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This new function allows us to support hole-punch for XIP files by zeroing a partial page, as opposed to the xip_truncate_page() function which can only truncate to the end of the page. Reimplement xip_truncate_page() as a macro that calls xip_zero_page_range(). Signed-off-by: Matthew Wilcox [ported to 3.13-rc2] Signed-off-by: Ross Zwisler --- Documentation/filesystems/xip.txt | 1 + fs/xip.c | 15 +++++++++------ include/linux/fs.h | 11 +++++++++-- 3 files changed, 19 insertions(+), 8 deletions(-) diff --git a/Documentation/filesystems/xip.txt b/Documentation/filesystems/xip.txt index 520e73a..a8bccb6 100644 --- a/Documentation/filesystems/xip.txt +++ b/Documentation/filesystems/xip.txt @@ -55,6 +55,7 @@ Filesystem support consists of for fault and page_mkwrite (which should probably call xip_fault() and xip_mkwrite(), passing the appropriate get_block() callback) - calling xip_truncate_page() instead of block_truncate_page() for XIP files +- calling xip_zero_page_range() instead of zero_user() for XIP files - ensuring that there is sufficient locking between reads, writes, truncates and page faults diff --git a/fs/xip.c b/fs/xip.c index 3f5f081..9087e0f 100644 --- a/fs/xip.c +++ b/fs/xip.c @@ -357,13 +357,16 @@ int xip_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, EXPORT_SYMBOL_GPL(xip_mkwrite); /** - * xip_truncate_page - handle a partial page being truncated in an XIP file + * xip_zero_page_range - zero a range within a page of an XIP file * @inode: The file being truncated * @from: The file offset that is being truncated to + * @length: The number of bytes to zero * @get_block: The filesystem method used to translate file offsets to blocks * - * Similar to block_truncate_page(), this function can be called by a - * filesystem when it is truncating an XIP file to handle the partial page. + * This function can be called by a filesystem when it is zeroing part of a + * page in an XIP file. This is intended for hole-punch operations. If + * you are truncating a file, the helper function xip_truncate_page() may be + * more convenient. * * We work in terms of PAGE_CACHE_SIZE here for commonality with * block_truncate_page(), but we could go down to PAGE_SIZE if the filesystem @@ -371,12 +374,12 @@ EXPORT_SYMBOL_GPL(xip_mkwrite); * block size is smaller than PAGE_SIZE, we have to zero the rest of the page * since the file might be mmaped. */ -int xip_truncate_page(struct inode *inode, loff_t from, get_block_t get_block) +int xip_zero_page_range(struct inode *inode, loff_t from, unsigned length, + get_block_t get_block) { struct buffer_head bh; pgoff_t index = from >> PAGE_CACHE_SHIFT; unsigned offset = from & (PAGE_CACHE_SIZE-1); - unsigned length = PAGE_CACHE_ALIGN(from) - from; int err; /* Block boundary? Nothing to do */ @@ -398,4 +401,4 @@ int xip_truncate_page(struct inode *inode, loff_t from, get_block_t get_block) return 0; } -EXPORT_SYMBOL_GPL(xip_truncate_page); +EXPORT_SYMBOL_GPL(xip_zero_page_range); diff --git a/include/linux/fs.h b/include/linux/fs.h index c93671a..04338a3 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2509,7 +2509,7 @@ extern int nonseekable_open(struct inode * inode, struct file * filp); #ifdef CONFIG_FS_XIP int xip_clear_blocks(struct inode *, sector_t block, long size); -int xip_truncate_page(struct inode *, loff_t from, get_block_t); +int xip_zero_page_range(struct inode *, loff_t from, unsigned len, get_block_t); ssize_t xip_do_io(int rw, struct kiocb *, struct inode *, const struct iovec *, loff_t, unsigned segs, get_block_t, dio_iodone_t, int flags); int xip_fault(struct vm_area_struct *, struct vm_fault *, get_block_t); @@ -2520,7 +2520,8 @@ static inline int xip_clear_blocks(struct inode *i, sector_t blk, long sz) return 0; } -static inline int xip_truncate_page(struct inode *i, loff_t frm, get_block_t gb) +static inline int xip_zero_page_range(struct inode *inode, loff_t from, + unsigned len, get_block_t gb) { return 0; } @@ -2533,6 +2534,12 @@ static inline ssize_t xip_do_io(int rw, struct kiocb *iocb, struct inode *inode, } #endif +/* Can't be a function because PAGE_CACHE_ALIGN is defined in pagemap.h */ +#define xip_truncate_page(inode, from, get_block) \ + xip_zero_page_range(inode, from, PAGE_CACHE_ALIGN(from) - from, \ + get_block) + + #ifdef CONFIG_BLOCK typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode, loff_t file_offset); -- 1.8.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/