From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759180Ab2IETCn (ORCPT ); Wed, 5 Sep 2012 15:02:43 -0400 Received: from cantor2.suse.de ([195.135.220.15]:32975 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754365Ab2IETCm (ORCPT ); Wed, 5 Sep 2012 15:02:42 -0400 Date: Wed, 5 Sep 2012 21:02:39 +0200 From: Jan Kara To: Ian Abbott Cc: lkml , linux-fsdevel@vger.kernel.org, Jan Kara Subject: Re: [PATCH v4] UDF: Add support for O_DIRECT Message-ID: <20120905190239.GK18051@quack.suse.cz> References: <20120905160019.GG18051@quack.suse.cz> <1346863471-3702-1-git-send-email-abbotti@mev.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1346863471-3702-1-git-send-email-abbotti@mev.co.uk> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 05-09-12 17:44:31, Ian Abbott wrote: > Add support for the O_DIRECT flag. There are two cases to deal with: > > 1. Small files stored in the ICB (inode control block?): just return 0 > from the new udf_adinicb_direct_IO() handler to fall back to buffered > I/O. > > 2. Larger files, not stored in the ICB: nothing special here. Just call > blockdev_direct_IO() from our new udf_direct_IO() handler and tidy up > any blocks instantiated outside i_size on error. This is pretty > standard. Factor error handling code out of udf_write_begin() into new > function udf_write_failed() so it can also be called by udf_direct_IO(). > > Also change the whitespace in udf_aops to make it a bit neater. Thanks! I've added the patch to my tree. Honza > > Signed-off-by: Ian Abbott > --- > v2: Rework error handling in udf_direct_IO to avoid calling deprecated > vmtruncate(). > v3: Rebased to next-20120904. > v4: Removed special handling in udf_adinicb_writepage() as that turned > out to be a bug in the handling of buffered writes for files in ICB, > fixed by Jan Kara's patch "udf: Fix data corruption for files in > ICB", dated 2012-09-05. I've tested it with that patch and it seems > to work without corrupting file data in the ICB. > --- > fs/udf/file.c | 9 +++++++++ > fs/udf/inode.c | 52 ++++++++++++++++++++++++++++++++++++---------------- > 2 files changed, 45 insertions(+), 16 deletions(-) > > diff --git a/fs/udf/file.c b/fs/udf/file.c > index d1c6093..77b5953 100644 > --- a/fs/udf/file.c > +++ b/fs/udf/file.c > @@ -118,11 +118,20 @@ static int udf_adinicb_write_end(struct file *file, > return simple_write_end(file, mapping, pos, len, copied, page, fsdata); > } > > +static ssize_t udf_adinicb_direct_IO(int rw, struct kiocb *iocb, > + const struct iovec *iov, > + loff_t offset, unsigned long nr_segs) > +{ > + /* Fallback to buffered I/O. */ > + return 0; > +} > + > const struct address_space_operations udf_adinicb_aops = { > .readpage = udf_adinicb_readpage, > .writepage = udf_adinicb_writepage, > .write_begin = udf_adinicb_write_begin, > .write_end = udf_adinicb_write_end, > + .direct_IO = udf_adinicb_direct_IO, > }; > > static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov, > diff --git a/fs/udf/inode.c b/fs/udf/inode.c > index 1a0588e..b905448 100644 > --- a/fs/udf/inode.c > +++ b/fs/udf/inode.c > @@ -95,6 +95,22 @@ void udf_evict_inode(struct inode *inode) > } > } > > +static void udf_write_failed(struct address_space *mapping, loff_t to) > +{ > + struct inode *inode = mapping->host; > + struct udf_inode_info *iinfo = UDF_I(inode); > + loff_t isize = inode->i_size; > + > + if (to > isize) { > + truncate_pagecache(inode, to, isize); > + if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) { > + down_write(&iinfo->i_data_sem); > + udf_truncate_extents(inode); > + up_write(&iinfo->i_data_sem); > + } > + } > +} > + > static int udf_writepage(struct page *page, struct writeback_control *wbc) > { > return block_write_full_page(page, udf_get_block, wbc); > @@ -124,21 +140,24 @@ static int udf_write_begin(struct file *file, struct address_space *mapping, > int ret; > > ret = block_write_begin(mapping, pos, len, flags, pagep, udf_get_block); > - if (unlikely(ret)) { > - struct inode *inode = mapping->host; > - struct udf_inode_info *iinfo = UDF_I(inode); > - loff_t isize = inode->i_size; > - > - if (pos + len > isize) { > - truncate_pagecache(inode, pos + len, isize); > - if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) { > - down_write(&iinfo->i_data_sem); > - udf_truncate_extents(inode); > - up_write(&iinfo->i_data_sem); > - } > - } > - } > + if (unlikely(ret)) > + udf_write_failed(mapping, pos + len); > + return ret; > +} > > +static ssize_t udf_direct_IO(int rw, struct kiocb *iocb, > + const struct iovec *iov, > + loff_t offset, unsigned long nr_segs) > +{ > + struct file *file = iocb->ki_filp; > + struct address_space *mapping = file->f_mapping; > + struct inode *inode = mapping->host; > + ssize_t ret; > + > + ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs, > + udf_get_block); > + if (unlikely(ret < 0 && (rw && WRITE))) > + udf_write_failed(mapping, offset + iov_length(iov, nr_segs)); > return ret; > } > > @@ -152,8 +171,9 @@ const struct address_space_operations udf_aops = { > .readpages = udf_readpages, > .writepage = udf_writepage, > .writepages = udf_writepages, > - .write_begin = udf_write_begin, > - .write_end = generic_write_end, > + .write_begin = udf_write_begin, > + .write_end = generic_write_end, > + .direct_IO = udf_direct_IO, > .bmap = udf_bmap, > }; > > -- > 1.7.12 > -- Jan Kara SUSE Labs, CR