Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754025Ab1EaAvI (ORCPT ); Mon, 30 May 2011 20:51:08 -0400 Received: from smtp-out.google.com ([74.125.121.67]:49829 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750862Ab1EaAvF (ORCPT ); Mon, 30 May 2011 20:51:05 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version:content-type; b=M0cQZVNnhhZ45YarJM7h8nUCX5YEL6Mqtf/tKqPCuFXYSObVAVt8Xob2dk0aU1N8UA tDZUZZkzptq4dCIOa71A== Date: Mon, 30 May 2011 17:51:02 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@sister.anvils To: Andrew Morton cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 11/14] mm: tidy vmtruncate_range and related functions In-Reply-To: Message-ID: References: User-Agent: Alpine 2.00 (LSU 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4196 Lines: 110 Use consistent variable names in truncate_pagecache(), truncate_setsize(), vmtruncate() and vmtruncate_range(). unmap_mapping_range() and vmtruncate_range() have mismatched interfaces: don't change either, but make the vmtruncates more precise about what they expect unmap_mapping_range() to do. vmtruncate_range() is currently called only with page-aligned start and end+1: can handle unaligned start, but unaligned end+1 would hit BUG_ON in truncate_inode_pages_range() (lacks partial clearing of the end page). Signed-off-by: Hugh Dickins --- mm/truncate.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) --- linux.orig/mm/truncate.c 2011-05-30 14:15:29.000000000 -0700 +++ linux/mm/truncate.c 2011-05-30 14:51:03.553127951 -0700 @@ -528,8 +528,8 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages /** * truncate_pagecache - unmap and remove pagecache that has been truncated * @inode: inode - * @old: old file offset - * @new: new file offset + * @oldsize: old file size + * @newsize: new file size * * inode's new i_size must already be written before truncate_pagecache * is called. @@ -541,9 +541,10 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages * situations such as writepage being called for a page that has already * had its underlying blocks deallocated. */ -void truncate_pagecache(struct inode *inode, loff_t old, loff_t new) +void truncate_pagecache(struct inode *inode, loff_t oldsize, loff_t newsize) { struct address_space *mapping = inode->i_mapping; + loff_t holebegin = round_up(newsize, PAGE_SIZE); /* * unmap_mapping_range is called twice, first simply for @@ -554,9 +555,9 @@ void truncate_pagecache(struct inode *in * truncate_inode_pages finishes, hence the second * unmap_mapping_range call must be made for correctness. */ - unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1); - truncate_inode_pages(mapping, new); - unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1); + unmap_mapping_range(mapping, holebegin, 0, 1); + truncate_inode_pages(mapping, newsize); + unmap_mapping_range(mapping, holebegin, 0, 1); } EXPORT_SYMBOL(truncate_pagecache); @@ -586,29 +587,31 @@ EXPORT_SYMBOL(truncate_setsize); /** * vmtruncate - unmap mappings "freed" by truncate() syscall * @inode: inode of the file used - * @offset: file offset to start truncating + * @newsize: file offset to start truncating * * This function is deprecated and truncate_setsize or truncate_pagecache * should be used instead, together with filesystem specific block truncation. */ -int vmtruncate(struct inode *inode, loff_t offset) +int vmtruncate(struct inode *inode, loff_t newsize) { int error; - error = inode_newsize_ok(inode, offset); + error = inode_newsize_ok(inode, newsize); if (error) return error; - truncate_setsize(inode, offset); + truncate_setsize(inode, newsize); if (inode->i_op->truncate) inode->i_op->truncate(inode); return 0; } EXPORT_SYMBOL(vmtruncate); -int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end) +int vmtruncate_range(struct inode *inode, loff_t lstart, loff_t lend) { struct address_space *mapping = inode->i_mapping; + loff_t holebegin = round_up(lstart, PAGE_SIZE); + loff_t holelen = 1 + lend - holebegin; /* * If the underlying filesystem is not going to provide @@ -620,10 +623,10 @@ int vmtruncate_range(struct inode *inode mutex_lock(&inode->i_mutex); down_write(&inode->i_alloc_sem); - unmap_mapping_range(mapping, offset, (end - offset), 1); - inode->i_op->truncate_range(inode, offset, end); + unmap_mapping_range(mapping, holebegin, holelen, 1); + inode->i_op->truncate_range(inode, lstart, lend); /* unmap again to remove racily COWed private pages */ - unmap_mapping_range(mapping, offset, (end - offset), 1); + unmap_mapping_range(mapping, holebegin, holelen, 1); up_write(&inode->i_alloc_sem); mutex_unlock(&inode->i_mutex); -- 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/