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dosfs: Use peek support

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This speeds up reading fragmented files.

Fix #3689
This commit is contained in:
Christian Mauderer
2021-01-21 16:53:55 +01:00
parent 6ae79e6df6
commit fd639b8abf
3 changed files with 31 additions and 5 deletions
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10
cpukit/libfs/src/dosfs/fat.c
View File

@@ -200,6 +200,16 @@ _fat_block_read(
return cmpltd;
}
void
fat_block_peek(
fat_fs_info_t *fs_info,
const uint32_t blk,
const uint32_t blk_cnt
)
{
rtems_bdbuf_peek(fs_info->vol.dd, blk, blk_cnt);
}
static ssize_t
fat_block_write(
fat_fs_info_t *fs_info,

5
cpukit/libfs/src/dosfs/fat.h
View File

@@ -499,6 +499,11 @@ _fat_block_read(fat_fs_info_t *fs_info,
uint32_t count,
void *buff);
void
fat_block_peek(fat_fs_info_t *fs_info,
const uint32_t blk,
const uint32_t blk_cnt);
ssize_t
fat_cluster_write(fat_fs_info_t *fs_info,
uint32_t start_cln,

21
cpukit/libfs/src/dosfs/fat_file.c
View File

@@ -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;
}