diff options
| -rw-r--r-- | fs/fat/dir.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/fs/fat/dir.c b/fs/fat/dir.c index e5ae1b720dd..895049b2ac9 100644 --- a/fs/fat/dir.c +++ b/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 @@ 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: |