From: Matthew Wilcox Subject: [PATCH v5 08/22] Change xip_truncate_page to take a get_block parameter Date: Wed, 15 Jan 2014 20:24:26 -0500 Message-ID: References: Cc: Matthew Wilcox To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-ext4@vger.kernel.org Return-path: 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 S1752483AbaAPBZG (ORCPT ); Wed, 15 Jan 2014 20:25:06 -0500 In-Reply-To: In-Reply-To: References: Sender: linux-ext4-owner@vger.kernel.org List-ID: Just like nobh_truncate_page() and block_truncate_page() Signed-off-by: Matthew Wilcox --- fs/ext2/inode.c | 2 +- fs/xip.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/fs.h | 4 ++-- mm/filemap_xip.c | 40 ---------------------------------------- 4 files changed, 47 insertions(+), 43 deletions(-) diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 3d11f1d..c531700 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -1207,7 +1207,7 @@ static int ext2_setsize(struct inode *inode, loff_t newsize) inode_dio_wait(inode); if (IS_XIP(inode)) - error = xip_truncate_page(inode->i_mapping, newsize); + error = xip_truncate_page(inode, newsize, ext2_get_block); else if (test_opt(inode->i_sb, NOBH)) error = nobh_truncate_page(inode->i_mapping, newsize, ext2_get_block); diff --git a/fs/xip.c b/fs/xip.c index bdedd56..aacb6a8 100644 --- a/fs/xip.c +++ b/fs/xip.c @@ -321,3 +321,47 @@ int xip_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, return result; } EXPORT_SYMBOL_GPL(xip_mkwrite); + +/** + * xip_truncate_page - handle a partial page being truncated in an XIP file + * @inode: The file being truncated + * @from: The file offset that is being truncated to + * @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. + * + * 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 + * took care of disposing of the unnecessary blocks. Even if the filesystem + * 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) +{ + 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 */ + if (!length) + return 0; + + memset(&bh, 0, sizeof(bh)); + bh.b_size = PAGE_CACHE_SIZE; + err = get_block(inode, index, &bh, 0); + if (err < 0) + return err; + if (buffer_mapped(&bh)) { + void *addr; + err = xip_get_addr(inode, &bh, &addr); + if (err) + return err; + memset(addr + offset, 0, length); + } + + return 0; +} +EXPORT_SYMBOL_GPL(xip_truncate_page); diff --git a/include/linux/fs.h b/include/linux/fs.h index aca9a1c..c77efa3 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2510,13 +2510,13 @@ extern int generic_file_open(struct inode * inode, struct file * filp); extern int nonseekable_open(struct inode * inode, struct file * filp); #ifdef CONFIG_FS_XIP -extern int xip_truncate_page(struct address_space *mapping, loff_t from); +int xip_truncate_page(struct inode *, loff_t from, 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); int xip_mkwrite(struct vm_area_struct *, struct vm_fault *, get_block_t); #else -static inline int xip_truncate_page(struct address_space *mapping, loff_t from) +static inline int xip_truncate_page(struct inode *i, loff_t frm, get_block_t gb) { return 0; } diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c index 9dd45f3..6316578 100644 --- a/mm/filemap_xip.c +++ b/mm/filemap_xip.c @@ -21,43 +21,3 @@ #include #include -/* - * truncate a page used for execute in place - * functionality is analog to block_truncate_page but does use get_xip_mem - * to get the page instead of page cache - */ -int -xip_truncate_page(struct address_space *mapping, loff_t from) -{ - pgoff_t index = from >> PAGE_CACHE_SHIFT; - unsigned offset = from & (PAGE_CACHE_SIZE-1); - unsigned blocksize; - unsigned length; - void *xip_mem; - unsigned long xip_pfn; - int err; - - BUG_ON(!mapping->a_ops->get_xip_mem); - - blocksize = 1 << mapping->host->i_blkbits; - length = offset & (blocksize - 1); - - /* Block boundary? Nothing to do */ - if (!length) - return 0; - - length = blocksize - length;