From: =?ISO-8859-15?Q?Luk=E1=A8_Czerner?= Subject: Re: [PATCH 02/12 v2] Revert "ext4: fix fsx truncate failure" Date: Thu, 19 Jul 2012 08:45:14 +0200 (CEST) Message-ID: References: <1342185555-21146-1-git-send-email-lczerner@redhat.com> <1342185555-21146-2-git-send-email-lczerner@redhat.com> <50070FD7.40301@redhat.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Lukas Czerner , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, tytso@mit.edu, achender@linux.vnet.ibm.com To: Eric Sandeen Return-path: In-Reply-To: <50070FD7.40301@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Wed, 18 Jul 2012, Eric Sandeen wrote: > Date: Wed, 18 Jul 2012 14:34:47 -0500 > From: Eric Sandeen > To: Lukas Czerner > Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, tytso@mit.edu, > achender@linux.vnet.ibm.com > Subject: Re: [PATCH 02/12 v2] Revert "ext4: fix fsx truncate failure" > > On 7/13/12 8:19 AM, Lukas Czerner wrote: > > This reverts commit 189e868fa8fdca702eb9db9d8afc46b5cb9144c9. > > > > This commit reintroduces the use of ext4_block_truncate_page() in ext4 > > truncate operation instead of ext4_discard_partial_page_buffers(). > > And I think commit 15291164b22a357cb211b618adfef4fa82fc0de3 > jbd2: clear BH_Delay & BH_Unwritten in journal_unmap_buffer > > fixed the fsx problem referenced in that commit more properly. You're probably right, I'll test that with your test case and add it to the description. Thanks! -Lukas > > > The statement in the commit description that the truncate operation only > > zero block unaligned portion of the last page is not exactly right, > > since truncate_pagecache_range() also zeroes and invalidate the unaligned > > portion of the page. Then there is no need to zero and unmap it once more > > and ext4_block_truncate_page() was doing the right job, although we > > still need to update the buffer head containing the last block, which is > > exactly what ext4_block_truncate_page() is doing. > > > > This was tested on ppc64 machine with block size of 1024 bytes without > > any problems. > > > > Signed-off-by: Lukas Czerner > > --- > > fs/ext4/extents.c | 13 ++----------- > > fs/ext4/indirect.c | 13 ++----------- > > 2 files changed, 4 insertions(+), 22 deletions(-) > > > > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > > index 91341ec..ceab5f5 100644 > > --- a/fs/ext4/extents.c > > +++ b/fs/ext4/extents.c > > @@ -4222,7 +4222,6 @@ void ext4_ext_truncate(struct inode *inode) > > struct super_block *sb = inode->i_sb; > > ext4_lblk_t last_block; > > handle_t *handle; > > - loff_t page_len; > > int err = 0; > > > > /* > > @@ -4239,16 +4238,8 @@ void ext4_ext_truncate(struct inode *inode) > > if (IS_ERR(handle)) > > return; > > > > - if (inode->i_size % PAGE_CACHE_SIZE != 0) { > > - page_len = PAGE_CACHE_SIZE - > > - (inode->i_size & (PAGE_CACHE_SIZE - 1)); > > - > > - err = ext4_discard_partial_page_buffers(handle, > > - mapping, inode->i_size, page_len, 0); > > - > > - if (err) > > - goto out_stop; > > - } > > + if (inode->i_size & (sb->s_blocksize - 1)) > > + ext4_block_truncate_page(handle, mapping, inode->i_size); > > > > if (ext4_orphan_add(handle, inode)) > > goto out_stop; > > diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c > > index 830e1b2..a082b30 100644 > > --- a/fs/ext4/indirect.c > > +++ b/fs/ext4/indirect.c > > @@ -1349,9 +1349,7 @@ void ext4_ind_truncate(struct inode *inode) > > __le32 nr = 0; > > int n = 0; > > ext4_lblk_t last_block, max_block; > > - loff_t page_len; > > unsigned blocksize = inode->i_sb->s_blocksize; > > - int err; > > > > handle = start_transaction(inode); > > if (IS_ERR(handle)) > > @@ -1362,16 +1360,9 @@ void ext4_ind_truncate(struct inode *inode) > > max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1) > > >> EXT4_BLOCK_SIZE_BITS(inode->i_sb); > > > > - if (inode->i_size % PAGE_CACHE_SIZE != 0) { > > - page_len = PAGE_CACHE_SIZE - > > - (inode->i_size & (PAGE_CACHE_SIZE - 1)); > > - > > - err = ext4_discard_partial_page_buffers(handle, > > - mapping, inode->i_size, page_len, 0); > > - > > - if (err) > > + if (inode->i_size & (blocksize - 1)) > > + if (ext4_block_truncate_page(handle, mapping, inode->i_size)) > > goto out_stop; > > - } > > > > if (last_block != max_block) { > > n = ext4_block_to_path(inode, last_block, offsets, NULL); > > > > >