Joseph Qi
2017-Nov-28 01:13 UTC
[Ocfs2-devel] [PATCH 2/3] ocfs2: add ocfs2_overwrite_io function
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 <ghe at suse.com> > --- > 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, >
Gang He
2017-Nov-28 03:35 UTC
[Ocfs2-devel] [PATCH 2/3] ocfs2: add ocfs2_overwrite_io function
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 <ghe at suse.com> >> --- >> 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.> >> + 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.> > 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, >>