forked from len0rd/rockbox
modify fat cache entries atomic, this was potentially unsafe
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@5534 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jörg Hohensohn
parent
8be9775d53
commit
50dba1fad0
1 changed files with 24 additions and 12 deletions
|
|
@ -27,6 +27,7 @@
|
|||
#include "panic.h"
|
||||
#include "system.h"
|
||||
#include "timefuncs.h"
|
||||
#include "kernel.h"
|
||||
|
||||
#define BYTES2INT16(array,pos) \
|
||||
(array[pos] | (array[pos+1] << 8 ))
|
||||
|
|
@ -230,7 +231,7 @@ static struct bpb fat_bpbs[NUM_VOLUMES]; /* mounted partition info */
|
|||
|
||||
static int update_fsinfo(IF_MV_NONVOID(struct bpb* fat_bpb));
|
||||
static int bpb_is_sane(IF_MV_NONVOID(struct bpb* fat_bpb));
|
||||
static void *cache_fat_sector(IF_MV2(struct bpb* fat_bpb,) int secnum);
|
||||
static void *cache_fat_sector(IF_MV2(struct bpb* fat_bpb,) int secnum, bool dirty);
|
||||
static int create_dos_name(const unsigned char *name, unsigned char *newname);
|
||||
static unsigned int find_free_cluster(IF_MV2(struct bpb* fat_bpb,) unsigned int start);
|
||||
static int transfer(IF_MV2(struct bpb* fat_bpb,) unsigned int start, int count, char* buf, bool write );
|
||||
|
|
@ -250,6 +251,7 @@ struct fat_cache_entry
|
|||
|
||||
static char fat_cache_sectors[FAT_CACHE_SIZE][SECTOR_SIZE];
|
||||
static struct fat_cache_entry fat_cache[FAT_CACHE_SIZE];
|
||||
static struct mutex cache_mutex;
|
||||
|
||||
static int cluster2sec(IF_MV2(struct bpb* fat_bpb,) int cluster)
|
||||
{
|
||||
|
|
@ -299,6 +301,9 @@ void fat_size(IF_MV2(int volume,) unsigned int* size, unsigned int* free)
|
|||
void fat_init(void)
|
||||
{
|
||||
unsigned int i;
|
||||
|
||||
mutex_init(&cache_mutex);
|
||||
|
||||
/* mark the FAT cache as unused */
|
||||
for(i = 0;i < FAT_CACHE_SIZE;i++)
|
||||
{
|
||||
|
|
@ -488,7 +493,7 @@ void fat_recalc_free(IF_MV_NONVOID(int volume))
|
|||
{
|
||||
for (i = 0; i<fat_bpb->fatsize; i++) {
|
||||
unsigned int j;
|
||||
unsigned short* fat = cache_fat_sector(IF_MV2(fat_bpb,) i);
|
||||
unsigned short* fat = cache_fat_sector(IF_MV2(fat_bpb,) i, false);
|
||||
for (j = 0; j < CLUSTERS_PER_FAT16_SECTOR; j++) {
|
||||
unsigned int c = i * CLUSTERS_PER_FAT16_SECTOR + j;
|
||||
if ( c > fat_bpb->dataclusters+1 ) /* nr 0 is unused */
|
||||
|
|
@ -507,7 +512,7 @@ void fat_recalc_free(IF_MV_NONVOID(int volume))
|
|||
{
|
||||
for (i = 0; i<fat_bpb->fatsize; i++) {
|
||||
unsigned int j;
|
||||
unsigned int* fat = cache_fat_sector(IF_MV2(fat_bpb,) i);
|
||||
unsigned int* fat = cache_fat_sector(IF_MV2(fat_bpb,) i, false);
|
||||
for (j = 0; j < CLUSTERS_PER_FAT_SECTOR; j++) {
|
||||
unsigned int c = i * CLUSTERS_PER_FAT_SECTOR + j;
|
||||
if ( c > fat_bpb->dataclusters+1 ) /* nr 0 is unused */
|
||||
|
|
@ -621,7 +626,10 @@ static void flush_fat_sector(struct fat_cache_entry *fce,
|
|||
fce->dirty = false;
|
||||
}
|
||||
|
||||
static void *cache_fat_sector(IF_MV2(struct bpb* fat_bpb,) int fatsector)
|
||||
/* Note: The returned pointer is only safely valid until the next
|
||||
task switch! (Any subsequent ata read/write may yield.) */
|
||||
static void *cache_fat_sector(IF_MV2(struct bpb* fat_bpb,)
|
||||
int fatsector, bool dirty)
|
||||
{
|
||||
#ifndef HAVE_MULTIVOLUME
|
||||
struct bpb* fat_bpb = &fat_bpbs[0];
|
||||
|
|
@ -632,6 +640,8 @@ static void *cache_fat_sector(IF_MV2(struct bpb* fat_bpb,) int fatsector)
|
|||
unsigned char *sectorbuf = &fat_cache_sectors[cache_index][0];
|
||||
int rc;
|
||||
|
||||
mutex_lock(&cache_mutex); /* make changes atomic */
|
||||
|
||||
/* Delete the cache entry if it isn't the sector we want */
|
||||
if(fce->inuse && (fce->secnum != secnum
|
||||
#ifdef HAVE_MULTIVOLUME
|
||||
|
|
@ -657,6 +667,7 @@ static void *cache_fat_sector(IF_MV2(struct bpb* fat_bpb,) int fatsector)
|
|||
{
|
||||
DEBUGF( "cache_fat_sector() - Could not read sector %d"
|
||||
" (error %d)\n", secnum, rc);
|
||||
mutex_unlock(&cache_mutex);
|
||||
return NULL;
|
||||
}
|
||||
fce->inuse = true;
|
||||
|
|
@ -665,6 +676,9 @@ static void *cache_fat_sector(IF_MV2(struct bpb* fat_bpb,) int fatsector)
|
|||
fce->fat_vol = fat_bpb;
|
||||
#endif
|
||||
}
|
||||
if (dirty)
|
||||
fce->dirty = true; /* dirt remains, sticky until flushed */
|
||||
mutex_unlock(&cache_mutex);
|
||||
return sectorbuf;
|
||||
}
|
||||
|
||||
|
|
@ -686,7 +700,7 @@ static unsigned int find_free_cluster(IF_MV2(struct bpb* fat_bpb,) unsigned int
|
|||
for (i = 0; i<fat_bpb->fatsize; i++) {
|
||||
unsigned int j;
|
||||
unsigned int nr = (i + sector) % fat_bpb->fatsize;
|
||||
unsigned short* fat = cache_fat_sector(IF_MV2(fat_bpb,) nr);
|
||||
unsigned short* fat = cache_fat_sector(IF_MV2(fat_bpb,) nr, false);
|
||||
if ( !fat )
|
||||
break;
|
||||
for (j = 0; j < CLUSTERS_PER_FAT16_SECTOR; j++) {
|
||||
|
|
@ -714,7 +728,7 @@ static unsigned int find_free_cluster(IF_MV2(struct bpb* fat_bpb,) unsigned int
|
|||
for (i = 0; i<fat_bpb->fatsize; i++) {
|
||||
unsigned int j;
|
||||
unsigned int nr = (i + sector) % fat_bpb->fatsize;
|
||||
unsigned int* fat = cache_fat_sector(IF_MV2(fat_bpb,) nr);
|
||||
unsigned int* fat = cache_fat_sector(IF_MV2(fat_bpb,) nr, false);
|
||||
if ( !fat )
|
||||
break;
|
||||
for (j = 0; j < CLUSTERS_PER_FAT_SECTOR; j++) {
|
||||
|
|
@ -760,13 +774,12 @@ static int update_fat_entry(IF_MV2(struct bpb* fat_bpb,) unsigned int entry, uns
|
|||
if ( entry < 2 )
|
||||
panicf("Updating reserved FAT entry %d.\n",entry);
|
||||
|
||||
sec = cache_fat_sector(IF_MV2(fat_bpb,) sector);
|
||||
sec = cache_fat_sector(IF_MV2(fat_bpb,) sector, true);
|
||||
if (!sec)
|
||||
{
|
||||
DEBUGF( "update_fat_entry() - Could not cache sector %d\n", sector);
|
||||
return -1;
|
||||
}
|
||||
fat_cache[(sector + fat_bpb->bpb_rsvdseccnt) & FAT_CACHE_MASK].dirty = true;
|
||||
|
||||
if ( val ) {
|
||||
if (SWAB16(sec[offset]) == 0x0000 && fat_bpb->fsinfo.freecount > 0)
|
||||
|
|
@ -796,13 +809,12 @@ static int update_fat_entry(IF_MV2(struct bpb* fat_bpb,) unsigned int entry, uns
|
|||
if ( entry < 2 )
|
||||
panicf("Updating reserved FAT entry %d.\n",entry);
|
||||
|
||||
sec = cache_fat_sector(IF_MV2(fat_bpb,) sector);
|
||||
sec = cache_fat_sector(IF_MV2(fat_bpb,) sector, true);
|
||||
if (!sec)
|
||||
{
|
||||
DEBUGF( "update_fat_entry() - Could not cache sector %d\n", sector);
|
||||
return -1;
|
||||
}
|
||||
fat_cache[(sector + fat_bpb->bpb_rsvdseccnt) & FAT_CACHE_MASK].dirty = true;
|
||||
|
||||
if ( val ) {
|
||||
if (!(SWAB32(sec[offset]) & 0x0fffffff) &&
|
||||
|
|
@ -836,7 +848,7 @@ static int read_fat_entry(IF_MV2(struct bpb* fat_bpb,) unsigned int entry)
|
|||
int offset = entry % CLUSTERS_PER_FAT16_SECTOR;
|
||||
unsigned short* sec;
|
||||
|
||||
sec = cache_fat_sector(IF_MV2(fat_bpb,) sector);
|
||||
sec = cache_fat_sector(IF_MV2(fat_bpb,) sector, false);
|
||||
if (!sec)
|
||||
{
|
||||
DEBUGF( "read_fat_entry() - Could not cache sector %d\n", sector);
|
||||
|
|
@ -852,7 +864,7 @@ static int read_fat_entry(IF_MV2(struct bpb* fat_bpb,) unsigned int entry)
|
|||
int offset = entry % CLUSTERS_PER_FAT_SECTOR;
|
||||
unsigned int* sec;
|
||||
|
||||
sec = cache_fat_sector(IF_MV2(fat_bpb,) sector);
|
||||
sec = cache_fat_sector(IF_MV2(fat_bpb,) sector, false);
|
||||
if (!sec)
|
||||
{
|
||||
DEBUGF( "read_fat_entry() - Could not cache sector %d\n", sector);
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue