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 | 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,
--
1.8.5.6
