From fd639b8abf1b82a74d14fbfe0180d853bbb43855 Mon Sep 17 00:00:00 2001 From: Christian Mauderer Date: Thu, 21 Jan 2021 16:53:55 +0100 Subject: dosfs: Use peek support This speeds up reading fragmented files. Fix #3689 --- cpukit/libfs/src/dosfs/fat_file.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) (limited to 'cpukit/libfs/src/dosfs/fat_file.c') diff --git a/cpukit/libfs/src/dosfs/fat_file.c b/cpukit/libfs/src/dosfs/fat_file.c index b4af8a11ca..ef9df0a67c 100644 --- a/cpukit/libfs/src/dosfs/fat_file.c +++ b/cpukit/libfs/src/dosfs/fat_file.c @@ -301,8 +301,11 @@ fat_file_read( uint32_t ofs = 0; uint32_t save_ofs; uint32_t sec = 0; + uint32_t sec_peek = 0; uint32_t byte = 0; uint32_t c = 0; + uint32_t blk = 0; + uint32_t blk_cnt = 0; /* it couldn't be removed - otherwise cache update will be broken */ if (count == 0) @@ -345,19 +348,27 @@ fat_file_read( c = MIN(count, (fs_info->vol.bpc - ofs)); sec = fat_cluster_num_to_sector_num(fs_info, cur_cln); + + save_cln = cur_cln; + rc = fat_get_fat_cluster(fs_info, cur_cln, &cur_cln); + if ( rc != RC_OK ) + return rc; + + sec_peek = fat_cluster_num_to_sector_num(fs_info, cur_cln); + blk = fat_sector_num_to_block_num (fs_info, sec_peek); + blk_cnt = fs_info->vol.bpc >> fs_info->vol.bytes_per_block_log2; + if (blk_cnt == 0) + blk_cnt = 1; + fat_block_peek(fs_info, blk, blk_cnt); + sec += (ofs >> fs_info->vol.sec_log2); byte = ofs & (fs_info->vol.bps - 1); - ret = _fat_block_read(fs_info, sec, byte, c, buf + cmpltd); if ( ret < 0 ) return -1; count -= c; cmpltd += c; - save_cln = cur_cln; - rc = fat_get_fat_cluster(fs_info, cur_cln, &cur_cln); - if ( rc != RC_OK ) - return rc; ofs = 0; } -- cgit v1.2.3