Hi Gang, On 2017/12/28 18:07, 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 <g...@suse.com> > --- > fs/ocfs2/extent_map.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ > fs/ocfs2/extent_map.h | 3 +++ > 2 files changed, 48 insertions(+) > > diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c > index e4719e0..06cb964 100644 > --- a/fs/ocfs2/extent_map.c > +++ b/fs/ocfs2/extent_map.c > @@ -38,6 +38,7 @@ > #include "inode.h" > #include "super.h" > #include "symlink.h" > +#include "aops.h" > #include "ocfs2_trace.h" > > #include "buffer_head_io.h" > @@ -832,6 +833,50 @@ 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, struct buffer_head *di_bh, > + u64 map_start, u64 map_len) Here can the type of 'map_start' is struct loff_t and map_len is struct size_t?
Thanks, Alex > +{ > + int ret = 0, is_last; > + u32 mapping_end, cpos; > + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); > + struct ocfs2_extent_rec rec; > + > + if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) { > + if (ocfs2_size_fits_inline_data(di_bh, map_start + map_len)) > + return ret; > + else > + return -EAGAIN; > + } > + > + 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; > + } > + > + 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 = -EAGAIN; > +out: > + return ret; > +} > + > 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..1057586 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, struct buffer_head *di_bh, > + u64 map_start, u64 map_len); > + > 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, >