Karsten Wiese <[EMAIL PROTECTED]> writes:

> Please give this a try and commit to -mm or mainline, if approved.

Looks good. Thanks.  However, I tweaked the patch.

    - replace __getblk() to sb_getblk()
    - exclude root-dir of FAT12/FAT16 from readahead
    - exclude (sec_per_clus == 1) from readahead
    - move the all readahead stuff to one inline function

What do you think of the following patch?
-- 
OGAWA Hirofumi <[EMAIL PROTECTED]>


Signed-off-by: Karsten Wiese <[EMAIL PROTECTED]>
Signed-off-by: OGAWA Hirofumi <[EMAIL PROTECTED]>
---

 fs/fat/dir.c |   28 ++++++++++++++++++++++++++--
 1 files changed, 26 insertions(+), 2 deletions(-)

diff -puN fs/fat/dir.c~fat-sb_breadahead fs/fat/dir.c
--- linux-2.6.13-rc4/fs/fat/dir.c~fat-sb_breadahead     2005-08-04 
21:21:59.000000000 +0900
+++ linux-2.6.13-rc4-hirofumi/fs/fat/dir.c      2005-08-04 23:05:58.000000000 
+0900
@@ -30,6 +30,29 @@ static inline loff_t fat_make_i_pos(stru
                | (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 @@ next:
        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 @@ RecEnd:
 EODir:
        filp->f_pos = cpos;
 FillFailed:
-       if (bh)
-               brelse(bh);
+       brelse(bh);
        if (unicode)
                free_page((unsigned long)unicode);
 out:
_
-
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