From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751899AbdK1Iyd convert rfc822-to-8bit (ORCPT ); Tue, 28 Nov 2017 03:54:33 -0500 Received: from prv-mh.provo.novell.com ([137.65.248.74]:56435 "EHLO prv-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751623AbdK1Iyc (ORCPT ); Tue, 28 Nov 2017 03:54:32 -0500 Message-Id: <5A1D94BF020000F90009AE19@prv-mh.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.2.2 Date: Tue, 28 Nov 2017 01:54:23 -0700 From: "Gang He" To: , , , "Goldwyn Rodrigues" , Cc: , Subject: Re: [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> <123f1322-d453-4aca-ac95-63d6f90fd8a2@gmail.com> <5A1D49E5020000F90009AC66@prv-mh.provo.novell.com> <805fb849-dcc7-cbbc-02af-1c6116a88957@gmail.com> <5A1D7FC2020000F90009AD91@prv-mh.provo.novell.com> <1437e732-35ea-9022-3358-dbe7d2708009@gmail.com> In-Reply-To: <1437e732-35ea-9022-3358-dbe7d2708009@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Joseph, >>> > > On 17/11/28 15:24, Gang He wrote: >> Hello Joseph, >> >> >>>>> >> >>> >>> On 17/11/28 11:35, Gang He wrote: >>>> Hello Joseph, >>>> >>>> >>>>>>> >>>>> Hi Gang, >>>>> >>>>> On 17/11/27 17:46, 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. >>>>>> >>>>>> 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: >>>>> Should brelse(di_bh) be here? >>>> If the code jumps to out_unlock1 directly, the di_bh pointer should be NULL, > >>> it is not necessary to release. >>>> >>> Umm... No, once going out here, we have already taken inode lock. So >>> di_bh should be released. >> Sorry, you are right. >> >>> >>>>> >>>>>> + ocfs2_inode_unlock(inode, 0); >>>>>> + >>>>>> +out: >>>>>> + return (ret ? 0 : 1); >>>>> I don't think EAGAIN and other error code can be handled the same. We >>>>> have to distinguish them. >>>> Ok, I think we can add one line log to report the error in case the error is > >>> not EAGAIN. >>>> >>> My point is, there is no need to try again in several cases, e.g. EROFS >>> returned by ocfs2_get_clusters_nocache. >> In this function ocfs2_overwrite_io() only can return True(1) or False(0), > then I think we can only give a error print before return true/false. >> It is not necessary to return another value, but should let the user know > any possible error message. >>This is because you just ignore the error and convert it to 0 or 1. > But in your next patch, if !ocfs2_overwrite_io(), it will return EGAIN > to upper layer and let it try again. > But in some cases, e.g. EROFS, trying again is meaningless. That's why > we can't simply return 0 or 1 here. Also we have to distinguish the > error code in the next patch. I think that we have to use the return value if we want to propagate the errorno to the above. I will change the return value meanings of ocfs2_overwrite_io() function. return 0 means this is a overwrite allocated block IO. return -EGAIN means there are some blocks which are not allocated. return other -ERRNO means there is another error happened. Does it make sense? Thanks Gang > >> Thanks >> Gang >> >>> >>>>> >>>>> Thanks, >>>>> Joseph >>>>> >>>>>> +} >>>>>> + >>>>>> 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: Gang He Date: Tue, 28 Nov 2017 01:54:23 -0700 Subject: [Ocfs2-devel] [PATCH 2/3] ocfs2: add ocfs2_overwrite_io function In-Reply-To: <1437e732-35ea-9022-3358-dbe7d2708009@gmail.com> References: <1511775987-841-1-git-send-email-ghe@suse.com> <1511775987-841-3-git-send-email-ghe@suse.com> <123f1322-d453-4aca-ac95-63d6f90fd8a2@gmail.com> <5A1D49E5020000F90009AC66@prv-mh.provo.novell.com> <805fb849-dcc7-cbbc-02af-1c6116a88957@gmail.com> <5A1D7FC2020000F90009AD91@prv-mh.provo.novell.com> <1437e732-35ea-9022-3358-dbe7d2708009@gmail.com> Message-ID: <5A1D94BF020000F90009AE19@prv-mh.provo.novell.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: jlbec@evilplan.org, jiangqi903@gmail.com, hch@lst.de, Goldwyn Rodrigues , mfasheh@versity.com Cc: ocfs2-devel@oss.oracle.com, linux-kernel@vger.kernel.org Hi Joseph, >>> > > On 17/11/28 15:24, Gang He wrote: >> Hello Joseph, >> >> >>>>> >> >>> >>> On 17/11/28 11:35, Gang He wrote: >>>> Hello Joseph, >>>> >>>> >>>>>>> >>>>> Hi Gang, >>>>> >>>>> On 17/11/27 17:46, 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. >>>>>> >>>>>> 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: >>>>> Should brelse(di_bh) be here? >>>> If the code jumps to out_unlock1 directly, the di_bh pointer should be NULL, > >>> it is not necessary to release. >>>> >>> Umm... No, once going out here, we have already taken inode lock. So >>> di_bh should be released. >> Sorry, you are right. >> >>> >>>>> >>>>>> + ocfs2_inode_unlock(inode, 0); >>>>>> + >>>>>> +out: >>>>>> + return (ret ? 0 : 1); >>>>> I don't think EAGAIN and other error code can be handled the same. We >>>>> have to distinguish them. >>>> Ok, I think we can add one line log to report the error in case the error is > >>> not EAGAIN. >>>> >>> My point is, there is no need to try again in several cases, e.g. EROFS >>> returned by ocfs2_get_clusters_nocache. >> In this function ocfs2_overwrite_io() only can return True(1) or False(0), > then I think we can only give a error print before return true/false. >> It is not necessary to return another value, but should let the user know > any possible error message. >>This is because you just ignore the error and convert it to 0 or 1. > But in your next patch, if !ocfs2_overwrite_io(), it will return EGAIN > to upper layer and let it try again. > But in some cases, e.g. EROFS, trying again is meaningless. That's why > we can't simply return 0 or 1 here. Also we have to distinguish the > error code in the next patch. I think that we have to use the return value if we want to propagate the errorno to the above. I will change the return value meanings of ocfs2_overwrite_io() function. return 0 means this is a overwrite allocated block IO. return -EGAIN means there are some blocks which are not allocated. return other -ERRNO means there is another error happened. Does it make sense? Thanks Gang > >> Thanks >> Gang >> >>> >>>>> >>>>> Thanks, >>>>> Joseph >>>>> >>>>>> +} >>>>>> + >>>>>> 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, >>>>>> >>>>