summaryrefslogtreecommitdiff
path: root/fs
diff options
context:
space:
mode:
authorBenoît Thébaudeau <benoit.thebaudeau@advansee.com>2012-07-20 15:20:12 +0200
committerWolfgang Denk <wd@denx.de>2012-09-02 17:16:08 +0200
commitcd1b042c5c035719018cffb751714d30513af0a6 (patch)
treeaef17d32566d445ca603ef09715f1744e8fb0f0f /fs
parent88503ad3bb5a21a95fe388a1d45e303c206a4e9d (diff)
FAT: Fix redundant sector read
With the previous code, the remaining prefetched sectors were read again after each sector. With this patch, each sector is read only once, thus making the prefetch useful. Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Cc: Wolfgang Denk <wd@denx.de>
Diffstat (limited to 'fs')
-rw-r--r--fs/fat/fat.c59
1 files changed, 33 insertions, 26 deletions
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 48c88448a30..fbc2d7de111 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -775,7 +775,7 @@ do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
volume_info volinfo;
fsdata datablock;
fsdata *mydata = &datablock;
- dir_entry *dentptr;
+ dir_entry *dentptr = NULL;
__u16 prevcksum = 0xffff;
char *subname = "";
__u32 cursect;
@@ -874,19 +874,21 @@ do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
while (1) {
int i;
- debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
- cursect, mydata->clust_size, DIRENTSPERBLOCK);
+ if (j == 0) {
+ debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
+ cursect, mydata->clust_size, DIRENTSPERBLOCK);
- if (disk_read(cursect,
- (mydata->fatsize == 32) ?
- (mydata->clust_size) :
- PREFETCH_BLOCKS,
- do_fat_read_block) < 0) {
- debug("Error: reading rootdir block\n");
- goto exit;
- }
+ if (disk_read(cursect,
+ (mydata->fatsize == 32) ?
+ (mydata->clust_size) :
+ PREFETCH_BLOCKS,
+ do_fat_read_block) < 0) {
+ debug("Error: reading rootdir block\n");
+ goto exit;
+ }
- dentptr = (dir_entry *) do_fat_read_block;
+ dentptr = (dir_entry *) do_fat_read_block;
+ }
for (i = 0; i < DIRENTSPERBLOCK; i++) {
char s_name[14], l_name[VFAT_MAXLEN_BYTES];
@@ -1028,28 +1030,33 @@ do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
* completely processed.
*/
++j;
- int fat32_end = 0;
- if ((mydata->fatsize == 32) && (j == mydata->clust_size)) {
- int nxtsect = 0;
- int nxt_clust = 0;
+ int rootdir_end = 0;
+ if (mydata->fatsize == 32) {
+ if (j == mydata->clust_size) {
+ int nxtsect = 0;
+ int nxt_clust = 0;
- nxt_clust = get_fatent(mydata, root_cluster);
- fat32_end = CHECK_CLUST(nxt_clust, 32);
+ nxt_clust = get_fatent(mydata, root_cluster);
+ rootdir_end = CHECK_CLUST(nxt_clust, 32);
- nxtsect = mydata->data_begin +
- (nxt_clust * mydata->clust_size);
+ nxtsect = mydata->data_begin +
+ (nxt_clust * mydata->clust_size);
- root_cluster = nxt_clust;
+ root_cluster = nxt_clust;
- cursect = nxtsect;
- j = 0;
+ cursect = nxtsect;
+ j = 0;
+ }
} else {
- cursect++;
+ if (j == PREFETCH_BLOCKS)
+ j = 0;
+
+ rootdir_end = (++cursect - mydata->rootdir_sect >=
+ rootdir_size);
}
/* If end of rootdir reached */
- if ((mydata->fatsize == 32 && fat32_end) ||
- (mydata->fatsize != 32 && j == rootdir_size)) {
+ if (rootdir_end) {
if (dols == LS_ROOT) {
printf("\n%d file(s), %d dir(s)\n\n",
files, dirs);