From mboxrd@z Thu Jan 1 00:00:00 1970 From: He YunLei Subject: Re: [f2fs-dev] Dwrite with non-aligned offset and size Date: Tue, 2 Jun 2015 12:21:12 +0800 Message-ID: <556D2F38.4040304@huawei.com> References: <556C481C.1050400@huawei.com> <20150601230155.GB28650@jaegeuk-mac02.mot.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150601230155.GB28650@jaegeuk-mac02.mot.com> Sender: linux-fsdevel-owner@vger.kernel.org To: Jaegeuk Kim Cc: linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, Bintian , hujianyang@huawei.com List-Id: linux-f2fs-devel.lists.sourceforge.net On 2015/6/2 7:01, Jaegeuk Kim wrote: > On Mon, Jun 01, 2015 at 07:55:08PM +0800, He YunLei wrote: >> Hi Jaegeuk, >> >> We run ltp testcase with f2fs and obtain a TFAIL in diotest4, the result in detail is >> as fallow: >> >> dio04 >> >> <<>> >> tag=dio04 stime=1432278894 >> cmdline="diotest4" >> contacts="" >> analysis=exit >> <<>> >> diotest4 1 TPASS : Negative Offset >> diotest4 2 TPASS : removed >> diotest4 3 TFAIL : diotest4.c:129: write allows odd count.returns 1: Success >> diotest4 4 TFAIL : diotest4.c:183: Odd count of read and write >> diotest4 5 TPASS : Read beyond the file size >> ...... >> >> the result of ext4 with same environment: >> >> dio04 >> >> <<>> >> tag=dio04 stime=1432259643 >> cmdline="diotest4" >> contacts="" >> analysis=exit >> <<>> >> diotest4 1 TPASS : Negative Offset >> diotest4 2 TPASS : removed >> diotest4 3 TPASS : Odd count of read and write >> diotest4 4 TPASS : Read beyond the file size >> ...... >> >> Does f2fs allow dwrite with non-aligned offset and size? I check the code and found >> dwrite with non-aligned offset and size will turn into buffered write. Whether it will >> have some impact on user layer applications? > > It's not a big deal to return -EINVAL. > When I take a look at other filesystem behaviors, it seems there is no restriction. > Ext4 do a check in the function do_blockdev_direct_IO: if (align & blocksize_mask) { if (bdev) blkbits = blksize_bits(bdev_logical_block_size(bdev)); blocksize_mask = (1 << blkbits) - 1; if (align & blocksize_mask) goto out; } It will return -EINVAL if the alignment is not satisfied. In f2fs, it do the check by check_direct_IO() before blockdev_direct_IO(). The difference between the two methods is whether turn dwrite with non-aligned offset and size into buffered write. I am not very clear which one is better! Thanks, He >> >> I wrote a patch, not well tested, how do you think of it? > > Returning the error number would be good to me. > Could you write and sumbit a complete one? > > Thanks, > >> >> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >> index 9bedfa8..ba5d94c 100644 >> --- a/fs/f2fs/data.c >> +++ b/fs/f2fs/data.c >> @@ -2010,8 +2010,9 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, >> if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) >> return 0; >> >> - if (check_direct_IO(inode, iter, offset)) >> - return 0; >> + err = check_direct_IO(inode, iter, offset) >> + if (err) >> + return -EINVAL; >> >> trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter)); >> >> I wish you and other developers in this list could help me in a correct way. >> >> Thanks, >> He > > . > From mboxrd@z Thu Jan 1 00:00:00 1970 From: He YunLei Subject: Re: [f2fs-dev] Dwrite with non-aligned offset and size Date: Tue, 2 Jun 2015 12:21:12 +0800 Message-ID: <556D2F38.4040304@huawei.com> References: <556C481C.1050400@huawei.com> <20150601230155.GB28650@jaegeuk-mac02.mot.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: , , Bintian , To: Jaegeuk Kim Return-path: Received: from szxga03-in.huawei.com ([119.145.14.66]:1574 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751211AbbFBEYe (ORCPT ); Tue, 2 Jun 2015 00:24:34 -0400 In-Reply-To: <20150601230155.GB28650@jaegeuk-mac02.mot.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 2015/6/2 7:01, Jaegeuk Kim wrote: > On Mon, Jun 01, 2015 at 07:55:08PM +0800, He YunLei wrote: >> Hi Jaegeuk, >> >> We run ltp testcase with f2fs and obtain a TFAIL in diotest4, the result in detail is >> as fallow: >> >> dio04 >> >> <<>> >> tag=dio04 stime=1432278894 >> cmdline="diotest4" >> contacts="" >> analysis=exit >> <<>> >> diotest4 1 TPASS : Negative Offset >> diotest4 2 TPASS : removed >> diotest4 3 TFAIL : diotest4.c:129: write allows odd count.returns 1: Success >> diotest4 4 TFAIL : diotest4.c:183: Odd count of read and write >> diotest4 5 TPASS : Read beyond the file size >> ...... >> >> the result of ext4 with same environment: >> >> dio04 >> >> <<>> >> tag=dio04 stime=1432259643 >> cmdline="diotest4" >> contacts="" >> analysis=exit >> <<>> >> diotest4 1 TPASS : Negative Offset >> diotest4 2 TPASS : removed >> diotest4 3 TPASS : Odd count of read and write >> diotest4 4 TPASS : Read beyond the file size >> ...... >> >> Does f2fs allow dwrite with non-aligned offset and size? I check the code and found >> dwrite with non-aligned offset and size will turn into buffered write. Whether it will >> have some impact on user layer applications? > > It's not a big deal to return -EINVAL. > When I take a look at other filesystem behaviors, it seems there is no restriction. > Ext4 do a check in the function do_blockdev_direct_IO: if (align & blocksize_mask) { if (bdev) blkbits = blksize_bits(bdev_logical_block_size(bdev)); blocksize_mask = (1 << blkbits) - 1; if (align & blocksize_mask) goto out; } It will return -EINVAL if the alignment is not satisfied. In f2fs, it do the check by check_direct_IO() before blockdev_direct_IO(). The difference between the two methods is whether turn dwrite with non-aligned offset and size into buffered write. I am not very clear which one is better! Thanks, He >> >> I wrote a patch, not well tested, how do you think of it? > > Returning the error number would be good to me. > Could you write and sumbit a complete one? > > Thanks, > >> >> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >> index 9bedfa8..ba5d94c 100644 >> --- a/fs/f2fs/data.c >> +++ b/fs/f2fs/data.c >> @@ -2010,8 +2010,9 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, >> if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) >> return 0; >> >> - if (check_direct_IO(inode, iter, offset)) >> - return 0; >> + err = check_direct_IO(inode, iter, offset) >> + if (err) >> + return -EINVAL; >> >> trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter)); >> >> I wish you and other developers in this list could help me in a correct way. >> >> Thanks, >> He > > . >