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authorBjörn Stenberg <bjorn@haxx.se>2002-10-30 16:16:47 +0000
committerBjörn Stenberg <bjorn@haxx.se>2002-10-30 16:16:47 +0000
commitd2df3c01dc34157fe3c0d414df7c68687f6aaedc (patch)
tree47255fe8e397cd0fbef87438f5978a82e5140ba8
parentb4cf6a1a0be3b76184e2c6a4551c052d8abdaa32 (diff)
downloadrockbox-d2df3c01dc34157fe3c0d414df7c68687f6aaedc.tar.gz
rockbox-d2df3c01dc34157fe3c0d414df7c68687f6aaedc.zip
Improved find_free_cluster(). Split readwrite() in two to simplify debugging.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2783 a1c6a512-1295-4272-9138-f99709370657
-rw-r--r--firmware/drivers/fat.c175
1 files changed, 113 insertions, 62 deletions
diff --git a/firmware/drivers/fat.c b/firmware/drivers/fat.c
index 89b322e10a..40f9c47fa7 100644
--- a/firmware/drivers/fat.c
+++ b/firmware/drivers/fat.c
@@ -429,14 +429,15 @@ static int find_free_cluster(int startcluster)
int offset = startcluster % CLUSTERS_PER_FAT_SECTOR;
int i;
- for (i = sector; i<fat_bpb.fatsize; i++) {
+ for (i = 0; i<fat_bpb.fatsize; i++) {
int j;
- unsigned int* fat = cache_fat_sector(i);
+ int nr = (i + sector) % fat_bpb.fatsize;
+ unsigned int* fat = cache_fat_sector(nr);
if ( !fat )
break;
for (j = offset; j < CLUSTERS_PER_FAT_SECTOR; j++)
if (!(SWAB32(fat[j]) & 0x0fffffff)) {
- int c = i * CLUSTERS_PER_FAT_SECTOR + j;
+ int c = nr * CLUSTERS_PER_FAT_SECTOR + j;
LDEBUGF("find_free_cluster(%x) == %x\n",startcluster,c);
fat_bpb.fsinfo.nextfree = c;
return c;
@@ -472,8 +473,10 @@ static int update_fat_entry(unsigned int entry, unsigned int val)
if (!(SWAB32(sec[offset]) & 0x0fffffff))
fat_bpb.fsinfo.freecount--;
}
- else
- fat_bpb.fsinfo.freecount++;
+ else {
+ if (SWAB32(sec[offset]) & 0x0fffffff)
+ fat_bpb.fsinfo.freecount++;
+ }
/* don't change top 4 bits */
sec[offset] &= SWAB32(0xf0000000);
@@ -503,7 +506,6 @@ static int get_next_cluster(unsigned int cluster)
int next_cluster;
next_cluster = read_fat_entry(cluster);
- LDEBUGF("get_next_cluster(%x) == %x\n",cluster,next_cluster);
/* is this last cluster in chain? */
if ( next_cluster >= FAT_EOF_MARK )
@@ -630,6 +632,7 @@ static int add_dir_entry(struct fat_dir* dir,
while(!done)
{
+ bool new = false;
if (sec_cnt >= fat_bpb.bpb_secperclus)
{
int oldcluster;
@@ -646,26 +649,27 @@ static int add_dir_entry(struct fat_dir* dir,
LDEBUGF("Adding cluster to dir\n");
currdir = find_free_cluster(fat_bpb.fsinfo.nextfree);
if (!currdir) {
- currdir = find_free_cluster(0);
- if (!currdir) {
- DEBUGF("add_dir_entry(): Disk full!\n");
- return -1;
- }
+ DEBUGF("add_dir_entry(): Disk full!\n");
+ return -1;
}
update_fat_entry(oldcluster, currdir);
+ new = true;
+ memset(buf, 0, sizeof buf);
}
LDEBUGF("new cluster is %x\n", currdir);
sec = cluster2sec(currdir);
}
- LDEBUGF("Reading sector %x...\n", sec);
- /* Read the next sector in the current dir */
- err = ata_read_sectors(sec + fat_bpb.startsector,1,buf);
- if (err)
- {
- DEBUGF( "add_dir_entry() - Couldn't read dir sector"
- " (error code %d)\n", err);
- return -2;
+ if (!new) {
+ LDEBUGF("Reading sector %x...\n", sec);
+ /* Read the next sector in the current dir */
+ err = ata_read_sectors(sec + fat_bpb.startsector,1,buf);
+ if (err)
+ {
+ DEBUGF( "add_dir_entry() - Couldn't read dir sector"
+ " (error code %d)\n", err);
+ return -2;
+ }
}
if (need_to_update_last_empty_marker)
@@ -981,8 +985,7 @@ int fat_remove(struct fat_file* file)
return 0;
}
-int fat_readwrite( struct fat_file *file, int sectorcount,
- void* buf, bool write )
+int fat_read( struct fat_file *file, int sectorcount, void* buf )
{
int cluster = file->lastcluster;
int sector = file->lastsector;
@@ -990,48 +993,22 @@ int fat_readwrite( struct fat_file *file, int sectorcount,
int first=0, last=0;
int err, i;
- LDEBUGF( "fat_readwrite(file:%x,count:%d,buf:%x,%s)\n",
- cluster,sectorcount,buf,write?"write":"read");
- LDEBUGF( "fat_readwrite: c=%x s=%x n=%d\n", cluster,sector,numsec);
+ LDEBUGF( "fat_read(file:%x,count:%d,buf:%x)\n",
+ cluster,sectorcount,buf);
+ LDEBUGF( "fat_read: c=%x s=%x n=%d\n", cluster,sector,numsec);
if ( sector == -1 )
return 0;
- if (!write)
- first = last = sector;
+ first = last = sector;
/* find sequential sectors and read/write them all at once */
for (i=0; i<sectorcount && sector>=0; i++ ) {
numsec++;
- if ( numsec >= fat_bpb.bpb_secperclus || !cluster) {
- int oldcluster = cluster;
+ if ( numsec >= fat_bpb.bpb_secperclus ) {
cluster = get_next_cluster(cluster);
if (!cluster) {
- if ( write ) {
- if (!oldcluster) /* new file */
- cluster = find_free_cluster(fat_bpb.fsinfo.nextfree);
- else /* writing past end-of-file */
- cluster = find_free_cluster(oldcluster+1);
- if (!cluster) {
- /* no free cluster found after last,
- search from beginning */
- cluster = find_free_cluster(0);
- if (!cluster) {
- /* no free clusters. disk is full. */
- sector = -1;
- DEBUGF("fat_readwrite(): Disk full!\n");
- }
- }
- if ( cluster ) {
- if ( !oldcluster )
- file->firstcluster = cluster;
- else
- update_fat_entry(oldcluster, cluster);
- }
- }
- else {
- /* reading past end-of-file */
- sector = -1;
- }
+ /* reading past end-of-file */
+ sector = -1;
}
if (cluster) {
@@ -1045,21 +1022,15 @@ int fat_readwrite( struct fat_file *file, int sectorcount,
else
sector++;
- if (write && !first)
- first = last = sector;
-
if ( (sector != last+1) || /* not sequential any more? */
(i == sectorcount-1) || /* last sector requested? */
(last-first+1 == 256) ) { /* max 256 sectors per ata request */
int count = last - first + 1;
int start = first + fat_bpb.startsector;
LDEBUGF("s=%x, l=%x, f=%x, i=%d\n",sector,last,first,i);
- if (write)
- err = ata_write_sectors(start, count, buf);
- else
- err = ata_read_sectors(start, count, buf);
+ err = ata_read_sectors(start, count, buf);
if (err) {
- DEBUGF( "fat_readwrite() - Couldn't read sector %d"
+ DEBUGF( "fat_read() - Couldn't read sector %d"
" (error code %d)\n", sector,err);
return -2;
}
@@ -1076,6 +1047,86 @@ int fat_readwrite( struct fat_file *file, int sectorcount,
return sectorcount;
}
+int fat_write( struct fat_file *file, int sectorcount, void* buf )
+{
+ int cluster = file->lastcluster;
+ int sector = file->lastsector;
+ int numsec = file->sectornum;
+ int first=0, last=0;
+ int err, i;
+
+ LDEBUGF( "fat_write(file:%x,count:%d,buf:%x)\n",
+ cluster,sectorcount,buf);
+ LDEBUGF( "fat_write: c=%x s=%x n=%d\n", cluster,sector,numsec);
+ if ( sector == -1 )
+ return 0;
+
+ /* find sequential sectors and write them all at once */
+ for (i=0; i<sectorcount && sector>=0; i++ ) {
+ numsec++;
+
+ /* find a new cluster */
+ if ( numsec >= fat_bpb.bpb_secperclus || !cluster) {
+ int oldcluster = cluster;
+ cluster = get_next_cluster(cluster);
+ if (!cluster) {
+ if (!oldcluster)
+ cluster = find_free_cluster(fat_bpb.fsinfo.nextfree);
+ else
+ cluster = find_free_cluster(oldcluster+1);
+
+ if (cluster) {
+ if ( !oldcluster )
+ file->firstcluster = cluster;
+ else
+ update_fat_entry(oldcluster, cluster);
+ }
+ else {
+ sector = -1;
+ DEBUGF("fat_write(): Disk full!\n");
+ }
+ }
+
+ if (cluster) {
+ sector = cluster2sec(cluster);
+ LDEBUGF("cluster2sec(%x) == %x\n",cluster,sector);
+ if (sector<0)
+ return -1;
+ numsec=0;
+
+ if (!oldcluster)
+ first = last = sector;
+ }
+ }
+ else
+ sector++;
+
+ /* we start simple: one sector at a time */
+ err = ata_write_sectors(sector, 1, buf);
+ if (err) {
+ DEBUGF( "fat_write() - Couldn't write sector %d"
+ " (error code %d)\n", sector,err);
+ return -2;
+ }
+ ((char*)buf) += SECTOR_SIZE;
+ }
+
+ file->lastcluster = cluster;
+ file->lastsector = sector;
+ file->sectornum = numsec;
+
+ return sectorcount;
+}
+
+int fat_readwrite( struct fat_file *file, int sectorcount,
+ void* buf, bool write )
+{
+ if (write)
+ return fat_write(file, sectorcount, buf);
+ else
+ return fat_read(file, sectorcount, buf);
+}
+
int fat_seek(struct fat_file *file, int seeksector )
{
int cluster = file->firstcluster;