From: Theodore Ts'o Subject: Re: [PATCH] ext4: only call ext4_truncate when size <= isize Date: Mon, 22 Jun 2015 00:37:29 -0400 Message-ID: <20150622043729.GT29480@thunk.org> References: <1432049337-3520-1-git-send-email-jbacik@fb.com> <20150606202011.GC15306@thunk.org> <20150609160739.GT19168@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Josef Bacik , linux-ext4@vger.kernel.org To: =?utf-8?B?THVrw6HFoQ==?= Czerner Return-path: Received: from imap.thunk.org ([74.207.234.97]:47738 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753803AbbFVEhd (ORCPT ); Mon, 22 Jun 2015 00:37:33 -0400 Content-Disposition: inline In-Reply-To: <20150609160739.GT19168@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Jun 09, 2015 at 12:07:39PM -0400, Theodore Ts'o wrote: > > Unfortunately this patch is causing generic/239 to fail when run with > 1k blocksizes. So it turns out the original patch was completely busted; the on-disk i_size wasn't getting updated when we were truncating up. Part of the problem was the original way ATTR_SIZE was handled in ext4_setattr was a bit of a mess, and it made it hard to understand. So I've reworked patch completely to clean up ext4_setattr while I was it. - Ted >From 0d209259066ca93548189668d1eb4c9497913932 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Mon, 22 Jun 2015 00:31:26 -0400 Subject: [PATCH] ext4: only call ext4_truncate when size <= isize At LSF we decided that if we truncate up from isize we shouldn't trim fallocated blocks that were fallocated with KEEP_SIZE and are past the new i_size. This patch fixes ext4 to do this. [ Completely reworked patch so that i_disksize would actually get set when truncating up. Also reworked the code for handling truncate so that it's easier to handle. -- tytso ] Signed-off-by: Josef Bacik Signed-off-by: Theodore Ts'o Reviewed-by: Lukas Czerner --- fs/ext4/inode.c | 38 ++++++++++++++++++-------------------- 1 file changed, 18 insertions(+), 20 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index ae93f0b..e057c6f 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4681,8 +4681,10 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) ext4_journal_stop(handle); } - if (attr->ia_valid & ATTR_SIZE && attr->ia_size != inode->i_size) { + if (attr->ia_valid & ATTR_SIZE) { handle_t *handle; + loff_t oldsize = inode->i_size; + int shrink = (attr->ia_size <= inode->i_size); if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); @@ -4690,24 +4692,26 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) if (attr->ia_size > sbi->s_bitmap_maxbytes) return -EFBIG; } + if (!S_ISREG(inode->i_mode)) + return -EINVAL; if (IS_I_VERSION(inode) && attr->ia_size != inode->i_size) inode_inc_iversion(inode); - if (S_ISREG(inode->i_mode) && + if (ext4_should_order_data(inode) && (attr->ia_size < inode->i_size)) { - if (ext4_should_order_data(inode)) { - error = ext4_begin_ordered_truncate(inode, + error = ext4_begin_ordered_truncate(inode, attr->ia_size); - if (error) - goto err_out; - } + if (error) + goto err_out; + } + if (attr->ia_size != inode->i_size) { handle = ext4_journal_start(inode, EXT4_HT_INODE, 3); if (IS_ERR(handle)) { error = PTR_ERR(handle); goto err_out; } - if (ext4_handle_valid(handle)) { + if (ext4_handle_valid(handle) && shrink) { error = ext4_orphan_add(handle, inode); orphan = 1; } @@ -4726,15 +4730,13 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) up_write(&EXT4_I(inode)->i_data_sem); ext4_journal_stop(handle); if (error) { - ext4_orphan_del(NULL, inode); + if (orphan) + ext4_orphan_del(NULL, inode); goto err_out; } - } else { - loff_t oldsize = inode->i_size; - - i_size_write(inode, attr->ia_size); - pagecache_isize_extended(inode, oldsize, inode->i_size); } + if (!shrink) + pagecache_isize_extended(inode, oldsize, inode->i_size); /* * Blocks are going to be removed from the inode. Wait @@ -4754,13 +4756,9 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) * in data=journal mode to make pages freeable. */ truncate_pagecache(inode, inode->i_size); + if (shrink) + ext4_truncate(inode); } - /* - * We want to call ext4_truncate() even if attr->ia_size == - * inode->i_size for cases like truncation of fallocated space - */ - if (attr->ia_valid & ATTR_SIZE) - ext4_truncate(inode); if (!rc) { setattr_copy(inode, attr); -- 2.3.0 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in