From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753248AbdK1BOD (ORCPT ); Mon, 27 Nov 2017 20:14:03 -0500 Received: from mail-oi0-f65.google.com ([209.85.218.65]:35779 "EHLO mail-oi0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752572AbdK1BN6 (ORCPT ); Mon, 27 Nov 2017 20:13:58 -0500 X-Google-Smtp-Source: AGs4zMYPr8F03ivj7WbzbGa2prXqjnpjcRzVp/IKe+ci6DMRcWD4geiMBPmFU9FJS3wZ/gV9fGfnng== Subject: Re: [Ocfs2-devel] [PATCH 2/3] ocfs2: add ocfs2_overwrite_io function To: Gang He , mfasheh@versity.com, jlbec@evilplan.org, rgoldwyn@suse.com, hch@lst.de Cc: linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com References: <1511775987-841-1-git-send-email-ghe@suse.com> <1511775987-841-3-git-send-email-ghe@suse.com> From: Joseph Qi Message-ID: <123f1322-d453-4aca-ac95-63d6f90fd8a2@gmail.com> Date: Tue, 28 Nov 2017 09:13:51 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <1511775987-841-3-git-send-email-ghe@suse.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? > + 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. 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, >