exfat: remove 'rwoffset' in exfat_inode_info

Remove 'rwoffset' in exfat_inode_info and replace it with the parameter of
exfat_readdir().
Since rwoffset is referenced only by exfat_readdir(), it is not necessary
a exfat_inode_info's member.
Also, change cpos to point to the next of entry-set, and return the index
of dir-entry via dir_entry->entry.

Signed-off-by: Tetsuhiro Kohada <[e-mail]>
Acked-by: Sungjong Seo <[e-mail]>
Signed-off-by: Namjae Jeon <[e-mail]>

fs/exfat/dir.c

···
 }
 
 /* read a directory entry from the opened directory */
-static int exfat_readdir(struct inode *inode, struct exfat_dir_entry *dir_entry)
+static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry)
 {
-	int i, dentries_per_clu, dentries_per_clu_bits = 0;
+	int i, dentries_per_clu, dentries_per_clu_bits = 0, num_ext;
 	unsigned int type, clu_offset;
 	sector_t sector;
 	struct exfat_chain dir, clu;
···
 	struct super_block *sb = inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
-	unsigned int dentry = ei->rwoffset & 0xFFFFFFFF;
+	unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF;
 	struct buffer_head *bh;
 
 	/* check if the given file ID is opened */
···
 				continue;
 			}
 
+			num_ext = ep->dentry.file.num_ext;
 			dir_entry->attr = le16_to_cpu(ep->dentry.file.attr);
 			exfat_get_entry_time(sbi, &dir_entry->crtime,
 					ep->dentry.file.create_tz,
···
 				return -EIO;
 			dir_entry->size =
 				le64_to_cpu(ep->dentry.stream.valid_size);
+			dir_entry->entry = dentry;
 			brelse(bh);
 
 			ei->hint_bmap.off = dentry >> dentries_per_clu_bits;
 			ei->hint_bmap.clu = clu.dir;
 
-			ei->rwoffset = ++dentry;
+			*cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext);
 			return 0;
 		}
 
···
 	}
 
 	dir_entry->namebuf.lfn[0] = '\0';
-	ei->rwoffset = dentry;
+	*cpos = EXFAT_DEN_TO_B(dentry);
 	return 0;
 }
 
···
 	if (err)
 		goto unlock;
 get_new:
-	ei->rwoffset = EXFAT_B_TO_DEN(cpos);
-
 	if (cpos >= i_size_read(inode))
 		goto end_of_dir;
 
-	err = exfat_readdir(inode, &de);
+	err = exfat_readdir(inode, &cpos, &de);
 	if (err) {
 		/*
 		 * At least we tried to read a sector.  Move cpos to next sector
···
 		goto end_of_dir;
 	}
 
-	cpos = EXFAT_DEN_TO_B(ei->rwoffset);
-
 	if (!nb->lfn[0])
 		goto end_of_dir;
 
-	i_pos = ((loff_t)ei->start_clu << 32) |
-		((ei->rwoffset - 1) & 0xffffffff);
+	i_pos = ((loff_t)ei->start_clu << 32) |	(de.entry & 0xffffffff);
 	tmp = exfat_iget(sb, i_pos);
 	if (tmp) {
 		inum = tmp->i_ino;

fs/exfat/exfat_fs.h

···
 	 * the validation of hint_stat.
 	 */
 	unsigned int version;
-	/* file offset or dentry index for readdir */
-	loff_t rwoffset;
 
 	/* hint for cluster last accessed */
 	struct exfat_hint hint_bmap;

fs/exfat/file.c

···
 	/* hint information */
 	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
 	ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
-	if (ei->rwoffset > new_size)
-		ei->rwoffset = new_size;
 
 	/* hint_stat will be used if this is directory. */
 	ei->hint_stat.eidx = 0;

fs/exfat/inode.c

···
 	unsigned int local_clu_offset = clu_offset;
 	unsigned int num_to_be_allocated = 0, num_clusters = 0;
 
-	ei->rwoffset = EXFAT_CLU_TO_B(clu_offset, sbi);
-
 	if (EXFAT_I(inode)->i_size_ondisk > 0)
 		num_clusters =
 			EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->i_size_ondisk,
···
 	ei->hint_stat.eidx = 0;
 	ei->hint_stat.clu = info->start_clu;
 	ei->hint_femp.eidx = EXFAT_HINT_NONE;
-	ei->rwoffset = 0;
 	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
 	ei->i_pos = 0;
 

fs/exfat/super.c

···
 	ei->flags = ALLOC_FAT_CHAIN;
 	ei->type = TYPE_DIR;
 	ei->version = 0;
-	ei->rwoffset = 0;
 	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
 	ei->hint_stat.eidx = 0;
 	ei->hint_stat.clu = sbi->root_dir;