From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tao Ma Subject: Re: [PATCH v2] ext4: Create helper function for EXT4_IO_END_UNWRITTEN and i_aiodio_unwritten. Date: Wed, 26 Oct 2011 15:47:43 +0800 Message-ID: <4EA7BB1F.5060008@tao.ma> References: <1317375716-6125-1-git-send-email-tm@tao.ma> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Ted Ts'o To: linux-ext4@vger.kernel.org Return-path: Received: from oproxy4-pub.bluehost.com ([69.89.21.11]:34581 "HELO oproxy4-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754602Ab1JZHrr (ORCPT ); Wed, 26 Oct 2011 03:47:47 -0400 In-Reply-To: <1317375716-6125-1-git-send-email-tm@tao.ma> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 09/30/2011 05:41 PM, Tao Ma wrote: > From: Tao Ma > > EXT4_IO_END_UNWRITTEN flag set and the increase of i_aiodio_unwritten > should be done simultaneously since ext4_end_io_nolock always clear the > flag and decrease the counter in the same time. > > We have found some bugs that the flag is set while leaving > i_aiodio_unwritten unchanged(commit 32c80b32c053d). So this patch just tries > to create a helper function to wrap them to avoid any future bug. > The idea is inspired by Eric. > > Cc: Eric Sandeen > Signed-off-by: Tao Ma ping? > --- > This patch is based on another bug fix which hasn't been merged yet. > http://marc.info/?l=linux-ext4&m=131598536608613&w=2 > > fs/ext4/ext4.h | 9 +++++++++ > fs/ext4/extents.c | 18 ++++++------------ > fs/ext4/inode.c | 5 +---- > fs/ext4/page-io.c | 6 ++---- > 4 files changed, 18 insertions(+), 20 deletions(-) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 4cb030c..a9325f5 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -1241,6 +1241,15 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino) > ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)); > } > > +static inline void ext4_set_io_unwritten_flag(struct inode *inode, > + struct ext4_io_end *io_end) > +{ > + if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) { > + io_end->flag |= EXT4_IO_END_UNWRITTEN; > + atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); > + } > +} > + > /* > * Inode dynamic state flags > */ > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index 8f23589..31750af 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -3190,12 +3190,9 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode, > * that this IO needs to conversion to written when IO is > * completed > */ > - if (io) { > - if (!(io->flag & EXT4_IO_END_UNWRITTEN)) { > - io->flag = EXT4_IO_END_UNWRITTEN; > - atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); > - } > - } else > + if (io) > + ext4_set_io_unwritten_flag(inode, io); > + else > ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); > if (ext4_should_dioread_nolock(inode)) > map->m_flags |= EXT4_MAP_UNINIT; > @@ -3574,12 +3571,9 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, > * that we need to perform conversion when IO is done. > */ > if ((flags & EXT4_GET_BLOCKS_PRE_IO)) { > - if (io) { > - if (!(io->flag & EXT4_IO_END_UNWRITTEN)) { > - io->flag = EXT4_IO_END_UNWRITTEN; > - atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); > - } > - } else > + if (io) > + ext4_set_io_unwritten_flag(inode, io); > + else > ext4_set_inode_state(inode, > EXT4_STATE_DIO_UNWRITTEN); > } > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 4b37501..5d6fc9b 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -2685,10 +2685,7 @@ static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate) > * but being more careful is always safe for the future change. > */ > inode = io_end->inode; > - if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) { > - io_end->flag |= EXT4_IO_END_UNWRITTEN; > - atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); > - } > + ext4_set_io_unwritten_flag(inode, io_end); > > /* Add the io_end to per-inode completed io list*/ > spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags); > diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c > index 92f38ee..f5eec5e 100644 > --- a/fs/ext4/page-io.c > +++ b/fs/ext4/page-io.c > @@ -350,10 +350,8 @@ submit_and_retry: > if ((io_end->num_io_pages >= MAX_IO_PAGES) && > (io_end->pages[io_end->num_io_pages-1] != io_page)) > goto submit_and_retry; > - if (buffer_uninit(bh) && !(io_end->flag & EXT4_IO_END_UNWRITTEN)) { > - io_end->flag |= EXT4_IO_END_UNWRITTEN; > - atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); > - } > + if (buffer_uninit(bh)) > + ext4_set_io_unwritten_flag(inode, io_end); > io->io_end->size += bh->b_size; > io->io_next_block++; > ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh));