diff options
Diffstat (limited to 'fs/hpfs/map.c')
| -rw-r--r-- | fs/hpfs/map.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/fs/hpfs/map.c b/fs/hpfs/map.c index 4acb19d78359..3aa66ae1031e 100644 --- a/fs/hpfs/map.c +++ b/fs/hpfs/map.c @@ -17,7 +17,9 @@ __le32 *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block, struct quad_buffer_head *qbh, char *id) { secno sec; - if (hpfs_sb(s)->sb_chk) if (bmp_block * 16384 > hpfs_sb(s)->sb_fs_size) { + __le32 *ret; + unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14; + if (hpfs_sb(s)->sb_chk) if (bmp_block >= n_bands) { hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id); return NULL; } @@ -26,7 +28,23 @@ __le32 *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block, hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id); return NULL; } - return hpfs_map_4sectors(s, sec, qbh, 4); + ret = hpfs_map_4sectors(s, sec, qbh, 4); + if (ret) hpfs_prefetch_bitmap(s, bmp_block + 1); + return ret; +} + +void hpfs_prefetch_bitmap(struct super_block *s, unsigned bmp_block) +{ + unsigned to_prefetch, next_prefetch; + unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14; + if (unlikely(bmp_block >= n_bands)) + return; + to_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]); + if (unlikely(bmp_block + 1 >= n_bands)) + next_prefetch = 0; + else + next_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block + 1]); + hpfs_prefetch_sectors(s, to_prefetch, 4 + 4 * (to_prefetch + 4 == next_prefetch)); } /* |