From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751953AbdK1HcT convert rfc822-to-8bit (ORCPT ); Tue, 28 Nov 2017 02:32:19 -0500 Received: from smtp.h3c.com ([221.12.31.13]:24867 "EHLO h3cmg01-ex.h3c.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751318AbdK1HcS (ORCPT ); Tue, 28 Nov 2017 02:32:18 -0500 X-Greylist: delayed 1727 seconds by postgrey-1.27 at vger.kernel.org; Tue, 28 Nov 2017 02:32:17 EST From: Changwei Ge To: Gang He , "jlbec@evilplan.org" , "hch@lst.de" , Goldwyn Rodrigues , "mfasheh@versity.com" CC: "ocfs2-devel@oss.oracle.com" , "linux-kernel@vger.kernel.org" Subject: Re: [Ocfs2-devel] [PATCH 2/3] ocfs2: add ocfs2_overwrite_io function Thread-Topic: [Ocfs2-devel] [PATCH 2/3] ocfs2: add ocfs2_overwrite_io function Thread-Index: AQHTZ2TgDe49BvIQpEuIKB/pomhiSA== Date: Tue, 28 Nov 2017 05:48:58 +0000 Message-ID: <63ADC13FD55D6546B7DECE290D39E373F1470CC0@H3CMLB12-EX.srv.huawei-3com.com> References: <1511775987-841-1-git-send-email-ghe@suse.com> <1511775987-841-3-git-send-email-ghe@suse.com> <63ADC13FD55D6546B7DECE290D39E373F1470B4A@H3CMLB12-EX.srv.huawei-3com.com> <5A1D674A020000F90009AD06@prv-mh.provo.novell.com> Accept-Language: en-US, zh-CN Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.125.136.231] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/11/28 13:44, Gang He wrote: > Hi Changwei, > > >>>> >> Hi, >> Gang >> >> On 2017/11/27 17:48, Gang He wrote: >>> Add ocfs2_overwrite_io function, which is used to judge if >>> overwrite allocated blocks, otherwise, the write will bring extra >>> block allocation overhead. >>> >> >> Can you elaborate how this overhead is introduced? >> Forgive me, I don't figure it. > If the blocks have been allocated, we just write these block directly. > If these blocks have not been allocated, that means we need to allocate these block firstly before write, > this allocation will bring the IO invoking be blocked, if the upper application does not want take this kind of overhead, > he can pass a nowait flag to avoid and return immediately with a -EAGAIN error. Thanks for your answer and contribution. This makes sense. Changwei > > Thanks > Gang > >> >> Thanks, >> Changwei >> >>> Signed-off-by: Gang He >>> --- >>> fs/ocfs2/extent_map.c | 67 >> +++++++++++++++++++++++++++++++++++++++++++++++++++ >>> fs/ocfs2/extent_map.h | 3 +++ >>> 2 files changed, 70 insertions(+) >>> >>> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c >>> index e4719e0..98bf325 100644 >>> --- a/fs/ocfs2/extent_map.c >>> +++ b/fs/ocfs2/extent_map.c >>> @@ -832,6 +832,73 @@ int ocfs2_fiemap(struct inode *inode, struct >> fiemap_extent_info *fieinfo, >>> return ret; >>> } >>> >>> +/* Is IO overwriting allocated blocks? */ >>> +int ocfs2_overwrite_io(struct inode *inode, u64 map_start, u64 map_len, >>> + int wait) >>> +{ >>> + int ret = 0, is_last; >>> + u32 mapping_end, cpos; >>> + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); >>> + struct buffer_head *di_bh = NULL; >>> + struct ocfs2_extent_rec rec; >>> + >>> + if (wait) >>> + ret = ocfs2_inode_lock(inode, &di_bh, 0); >>> + else >>> + ret = ocfs2_try_inode_lock(inode, &di_bh, 0); >>> + if (ret) >>> + goto out; >>> + >>> + if (wait) >>> + down_read(&OCFS2_I(inode)->ip_alloc_sem); >>> + else { >>> + if (!down_read_trylock(&OCFS2_I(inode)->ip_alloc_sem)) { >>> + ret = -EAGAIN; >>> + goto out_unlock1; >>> + } >>> + } >>> + >>> + if ((OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) && >>> + ((map_start + map_len) <= i_size_read(inode))) >>> + goto out_unlock2; >>> + >>> + cpos = map_start >> osb->s_clustersize_bits; >>> + mapping_end = ocfs2_clusters_for_bytes(inode->i_sb, >>> + map_start + map_len); >>> + is_last = 0; >>> + while (cpos < mapping_end && !is_last) { >>> + ret = ocfs2_get_clusters_nocache(inode, di_bh, cpos, >>> + NULL, &rec, &is_last); >>> + if (ret) { >>> + mlog_errno(ret); >>> + goto out_unlock2; >>> + } >>> + >>> + if (rec.e_blkno == 0ULL) >>> + break; >>> + >>> + if (rec.e_flags & OCFS2_EXT_REFCOUNTED) >>> + break; >>> + >>> + cpos = le32_to_cpu(rec.e_cpos) + >>> + le16_to_cpu(rec.e_leaf_clusters); >>> + } >>> + >>> + if (cpos < mapping_end) >>> + ret = 1; >>> + >>> +out_unlock2: >>> + brelse(di_bh); >>> + >>> + up_read(&OCFS2_I(inode)->ip_alloc_sem); >>> + >>> +out_unlock1: >>> + ocfs2_inode_unlock(inode, 0); >>> + >>> +out: >>> + return (ret ? 0 : 1); >>> +} >>> + >>> int ocfs2_seek_data_hole_offset(struct file *file, loff_t *offset, int >> whence) >>> { >>> struct inode *inode = file->f_mapping->host; >>> diff --git a/fs/ocfs2/extent_map.h b/fs/ocfs2/extent_map.h >>> index 67ea57d..fd9e86a 100644 >>> --- a/fs/ocfs2/extent_map.h >>> +++ b/fs/ocfs2/extent_map.h >>> @@ -53,6 +53,9 @@ int ocfs2_extent_map_get_blocks(struct inode *inode, u64 >> v_blkno, u64 *p_blkno, >>> int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, >>> u64 map_start, u64 map_len); >>> >>> +int ocfs2_overwrite_io(struct inode *inode, u64 map_start, u64 map_len, >>> + int wait); >>> + >>> int ocfs2_seek_data_hole_offset(struct file *file, loff_t *offset, int >> origin); >>> >>> int ocfs2_xattr_get_clusters(struct inode *inode, u32 v_cluster, >>> > > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Changwei Ge Date: Tue, 28 Nov 2017 05:48:58 +0000 Subject: [Ocfs2-devel] [PATCH 2/3] ocfs2: add ocfs2_overwrite_io function References: <1511775987-841-1-git-send-email-ghe@suse.com> <1511775987-841-3-git-send-email-ghe@suse.com> <63ADC13FD55D6546B7DECE290D39E373F1470B4A@H3CMLB12-EX.srv.huawei-3com.com> <5A1D674A020000F90009AD06@prv-mh.provo.novell.com> Message-ID: <63ADC13FD55D6546B7DECE290D39E373F1470CC0@H3CMLB12-EX.srv.huawei-3com.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Gang He , "jlbec@evilplan.org" , "hch@lst.de" , Goldwyn Rodrigues , "mfasheh@versity.com" Cc: "ocfs2-devel@oss.oracle.com" , "linux-kernel@vger.kernel.org" On 2017/11/28 13:44, Gang He wrote: > Hi Changwei, > > >>>> >> Hi, >> Gang >> >> On 2017/11/27 17:48, Gang He wrote: >>> Add ocfs2_overwrite_io function, which is used to judge if >>> overwrite allocated blocks, otherwise, the write will bring extra >>> block allocation overhead. >>> >> >> Can you elaborate how this overhead is introduced? >> Forgive me, I don't figure it. > If the blocks have been allocated, we just write these block directly. > If these blocks have not been allocated, that means we need to allocate these block firstly before write, > this allocation will bring the IO invoking be blocked, if the upper application does not want take this kind of overhead, > he can pass a nowait flag to avoid and return immediately with a -EAGAIN error. Thanks for your answer and contribution. This makes sense. Changwei > > Thanks > Gang > >> >> Thanks, >> Changwei >> >>> Signed-off-by: Gang He >>> --- >>> fs/ocfs2/extent_map.c | 67 >> +++++++++++++++++++++++++++++++++++++++++++++++++++ >>> fs/ocfs2/extent_map.h | 3 +++ >>> 2 files changed, 70 insertions(+) >>> >>> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c >>> index e4719e0..98bf325 100644 >>> --- a/fs/ocfs2/extent_map.c >>> +++ b/fs/ocfs2/extent_map.c >>> @@ -832,6 +832,73 @@ int ocfs2_fiemap(struct inode *inode, struct >> fiemap_extent_info *fieinfo, >>> return ret; >>> } >>> >>> +/* Is IO overwriting allocated blocks? */ >>> +int ocfs2_overwrite_io(struct inode *inode, u64 map_start, u64 map_len, >>> + int wait) >>> +{ >>> + int ret = 0, is_last; >>> + u32 mapping_end, cpos; >>> + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); >>> + struct buffer_head *di_bh = NULL; >>> + struct ocfs2_extent_rec rec; >>> + >>> + if (wait) >>> + ret = ocfs2_inode_lock(inode, &di_bh, 0); >>> + else >>> + ret = ocfs2_try_inode_lock(inode, &di_bh, 0); >>> + if (ret) >>> + goto out; >>> + >>> + if (wait) >>> + down_read(&OCFS2_I(inode)->ip_alloc_sem); >>> + else { >>> + if (!down_read_trylock(&OCFS2_I(inode)->ip_alloc_sem)) { >>> + ret = -EAGAIN; >>> + goto out_unlock1; >>> + } >>> + } >>> + >>> + if ((OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) && >>> + ((map_start + map_len) <= i_size_read(inode))) >>> + goto out_unlock2; >>> + >>> + cpos = map_start >> osb->s_clustersize_bits; >>> + mapping_end = ocfs2_clusters_for_bytes(inode->i_sb, >>> + map_start + map_len); >>> + is_last = 0; >>> + while (cpos < mapping_end && !is_last) { >>> + ret = ocfs2_get_clusters_nocache(inode, di_bh, cpos, >>> + NULL, &rec, &is_last); >>> + if (ret) { >>> + mlog_errno(ret); >>> + goto out_unlock2; >>> + } >>> + >>> + if (rec.e_blkno == 0ULL) >>> + break; >>> + >>> + if (rec.e_flags & OCFS2_EXT_REFCOUNTED) >>> + break; >>> + >>> + cpos = le32_to_cpu(rec.e_cpos) + >>> + le16_to_cpu(rec.e_leaf_clusters); >>> + } >>> + >>> + if (cpos < mapping_end) >>> + ret = 1; >>> + >>> +out_unlock2: >>> + brelse(di_bh); >>> + >>> + up_read(&OCFS2_I(inode)->ip_alloc_sem); >>> + >>> +out_unlock1: >>> + ocfs2_inode_unlock(inode, 0); >>> + >>> +out: >>> + return (ret ? 0 : 1); >>> +} >>> + >>> int ocfs2_seek_data_hole_offset(struct file *file, loff_t *offset, int >> whence) >>> { >>> struct inode *inode = file->f_mapping->host; >>> diff --git a/fs/ocfs2/extent_map.h b/fs/ocfs2/extent_map.h >>> index 67ea57d..fd9e86a 100644 >>> --- a/fs/ocfs2/extent_map.h >>> +++ b/fs/ocfs2/extent_map.h >>> @@ -53,6 +53,9 @@ int ocfs2_extent_map_get_blocks(struct inode *inode, u64 >> v_blkno, u64 *p_blkno, >>> int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, >>> u64 map_start, u64 map_len); >>> >>> +int ocfs2_overwrite_io(struct inode *inode, u64 map_start, u64 map_len, >>> + int wait); >>> + >>> int ocfs2_seek_data_hole_offset(struct file *file, loff_t *offset, int >> origin); >>> >>> int ocfs2_xattr_get_clusters(struct inode *inode, u32 v_cluster, >>> > >