From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=FORGED_MUA_MOZILLA, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC3EFECE58E for ; Wed, 9 Oct 2019 06:22:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E6012133F for ; Wed, 9 Oct 2019 06:22:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727824AbfJIGWy (ORCPT ); Wed, 9 Oct 2019 02:22:54 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:23868 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726698AbfJIGWy (ORCPT ); Wed, 9 Oct 2019 02:22:54 -0400 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x996MLjA107605 for ; Wed, 9 Oct 2019 02:22:51 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2vh8m7txn7-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 09 Oct 2019 02:22:51 -0400 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 9 Oct 2019 07:22:45 +0100 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x996MiSp43123170 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 9 Oct 2019 06:22:44 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7C42842049; Wed, 9 Oct 2019 06:22:44 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 87D244204B; Wed, 9 Oct 2019 06:22:42 +0000 (GMT) Received: from [9.199.159.72] (unknown [9.199.159.72]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 9 Oct 2019 06:22:42 +0000 (GMT) Subject: Re: [PATCH v4 2/8] ext4: move out IOMAP_WRITE path into separate helper To: Matthew Bobrowski , tytso@mit.edu, jack@suse.cz, adilger.kernel@dilger.ca Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, hch@infradead.org, david@fromorbit.com, darrick.wong@oracle.com References: <99b317af0f20a170fba2e70695d7cca1597fb19a.1570100361.git.mbobrowski@mbobrowski.org> From: Ritesh Harjani Date: Wed, 9 Oct 2019 11:52:41 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <99b317af0f20a170fba2e70695d7cca1597fb19a.1570100361.git.mbobrowski@mbobrowski.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19100906-0016-0000-0000-000002B65809 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19100906-0017-0000-0000-000033175CDC Message-Id: <20191009062242.87D244204B@d06av24.portsmouth.uk.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-10-09_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910090058 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On 10/3/19 5:03 PM, Matthew Bobrowski wrote: > In preparation for porting across the direct I/O path to iomap, split > out the IOMAP_WRITE logic into a separate helper. This way, we don't > need to clutter the ext4_iomap_begin() callback. > > Signed-off-by: Matthew Bobrowski Minor comment, but otherwise. Patch looks good to me. You may add: Reviewed-by: Ritesh Harjani > --- > fs/ext4/inode.c | 110 ++++++++++++++++++++++++++---------------------- > 1 file changed, 60 insertions(+), 50 deletions(-) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 1ccdc14c4d69..caeb3dec0dec 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3439,6 +3439,62 @@ static int ext4_set_iomap(struct inode *inode, struct iomap *iomap, u16 type, > return 0; > } > > +static int ext4_iomap_alloc(struct inode *inode, > + unsigned flags, > + unsigned long first_block, > + struct ext4_map_blocks *map) > +{ > + handle_t *handle; > + u8 blkbits = inode->i_blkbits; > + int ret, dio_credits, retries = 0; > + > + /* > + * Trim mapping request to the maximum value that we can map > + * at once for direct I/O. > + */ > + if (map->m_len > DIO_MAX_BLOCKS) > + map->m_len = DIO_MAX_BLOCKS; > + dio_credits = ext4_chunk_trans_blocks(inode, map->m_len); > +retry: > + /* > + * Either we allocate blocks and then we don't get unwritten > + * extent so we have reserved enough credits, or the blocks > + * are already allocated and unwritten. In that case, the > + * extent conversion fits in the credits as well. > + */ > + handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits); > + if (IS_ERR(handle)) > + return PTR_ERR(handle); > + > + ret = ext4_map_blocks(handle, inode, map, EXT4_GET_BLOCKS_CREATE_ZERO); > + if (ret < 0) > + goto journal_stop; > + > + /* > + * If we have allocated blocks beyond the EOF, we need to make > + * sure that they get truncate if we crash before updating the > + * inode size metadata in ext4_iomap_end(). For faults, we > + * don't need to do that (and cannot due to the orphan list > + * operations needing an inode_lock()). If we happen to > + * instantiate blocks beyond EOF, it is because we race with a > + * truncate operation, which already has added the inode onto > + * the orphan list. > + */ > + if (!(flags & IOMAP_FAULT) && first_block + map->m_len > > + (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) { > + int err; > + > + err = ext4_orphan_add(handle, inode); > + if (err < 0) > + ret = err; > + } > +journal_stop: > + ext4_journal_stop(handle); > + if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) > + goto retry; > + return ret; > +} > + > static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > unsigned flags, struct iomap *iomap) > { > @@ -3500,62 +3556,16 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > } > } > } else if (flags & IOMAP_WRITE) { > - int dio_credits; > - handle_t *handle; > - int retries = 0; > - > - /* Trim mapping request to maximum we can map at once for DIO */ > - if (map.m_len > DIO_MAX_BLOCKS) > - map.m_len = DIO_MAX_BLOCKS; > - dio_credits = ext4_chunk_trans_blocks(inode, map.m_len); > -retry: > - /* > - * Either we allocate blocks and then we don't get unwritten > - * extent so we have reserved enough credits, or the blocks > - * are already allocated and unwritten and in that case > - * extent conversion fits in the credits as well. > - */ > - handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, > - dio_credits); > - if (IS_ERR(handle)) > - return PTR_ERR(handle); > - > - ret = ext4_map_blocks(handle, inode, &map, > - EXT4_GET_BLOCKS_CREATE_ZERO); > - if (ret < 0) { > - ext4_journal_stop(handle); > - if (ret == -ENOSPC && > - ext4_should_retry_alloc(inode->i_sb, &retries)) > - goto retry; > - return ret; > - } > - > - /* > - * If we added blocks beyond i_size, we need to make sure they > - * will get truncated if we crash before updating i_size in > - * ext4_iomap_end(). For faults we don't need to do that (and > - * even cannot because for orphan list operations inode_lock is > - * required) - if we happen to instantiate block beyond i_size, > - * it is because we race with truncate which has already added > - * the inode to the orphan list. > - */ > - if (!(flags & IOMAP_FAULT) && first_block + map.m_len > > - (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) { > - int err; > - > - err = ext4_orphan_add(handle, inode); > - if (err < 0) { > - ext4_journal_stop(handle); > - return err; > - } > - } > - ext4_journal_stop(handle); > + ret = ext4_iomap_alloc(inode, flags, first_block, &map); We don't need "first_block" argument here. Since map->m_lblk saves first_block directly above in the same function. No strong objection against ext4_iomap_alloc, but maybe ext4_iomap_map_write sounds better? Either way is fine though. > } else { > ret = ext4_map_blocks(NULL, inode, &map, 0); > if (ret < 0) > return ret; > } > > + if (ret < 0) > + return ret; > + > if (!ret) > type = delalloc ? IOMAP_DELALLOC : IOMAP_HOLE; > return ext4_set_iomap(inode, iomap, type, first_block, &map); >