---

yaml
---
r: 7365
b: refs/heads/master
c: f3ef6f6
h: refs/heads/master
i:
  7363: cdf59c3
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 378bac820be6a0ec95df8151524de73ad2b2d2ac
+refs/heads/master: f3ef6f63e5c575c136b39bb423a6e9a002932da7

trunk/fs/fat/dir.c

@@ -30,6 +30,29 @@ static inline loff_t fat_make_i_pos(struct super_block *sb,
 		| (de - (struct msdos_dir_entry *)bh->b_data);
 }
 
+static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
+				     sector_t phys)
+{
+	struct super_block *sb = dir->i_sb;
+	struct msdos_sb_info *sbi = MSDOS_SB(sb);
+	struct buffer_head *bh;
+	int sec;
+
+	/* This is not a first sector of cluster, or sec_per_clus == 1 */
+	if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
+		return;
+	/* root dir of FAT12/FAT16 */
+	if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
+		return;
+
+	bh = sb_getblk(sb, phys);
+	if (bh && !buffer_uptodate(bh)) {
+		for (sec = 0; sec < sbi->sec_per_clus; sec++)
+			sb_breadahead(sb, phys + sec);
+	}
+	brelse(bh);
+}
+
 /* Returns the inode number of the directory entry at offset pos. If bh is
    non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
    returned in bh.
@@ -58,6 +81,8 @@ static int fat__get_entry(struct inode *dir, loff_t *pos,
 	if (err || !phys)
 		return -1;	/* beyond EOF or error */
 
+	fat_dir_readahead(dir, iblock, phys);
+
 	*bh = sb_bread(sb, phys);
 	if (*bh == NULL) {
 		printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
@@ -635,8 +660,7 @@ static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,
 EODir:
 	filp->f_pos = cpos;
 FillFailed:
-	if (bh)
-		brelse(bh);
+	brelse(bh);
 	if (unicode)
 		free_page((unsigned long)unicode);
 out: