@@ -882,7 +882,7 @@ static int read_directory(BDRVVVFATState* s, int mapping_index)
return 0;
}
-static inline uint32_t sector2cluster(BDRVVVFATState* s,off_t sector_num)
+static inline int32_t sector2cluster(BDRVVVFATState* s,off_t sector_num)
{
return (sector_num - s->offset_to_root_dir) / s->sectors_per_cluster;
}
@@ -2981,6 +2981,7 @@ static int vvfat_write(BlockDriverState *bs, int64_t sector_num,
{
BDRVVVFATState *s = bs->opaque;
int i, ret;
+ int first_cluster, last_cluster;
DLOG(checkpoint());
@@ -2999,9 +3000,20 @@ DLOG(checkpoint());
if (sector_num < s->offset_to_fat)
return -1;
- for (i = sector2cluster(s, sector_num);
- i <= sector2cluster(s, sector_num + nb_sectors - 1);) {
- mapping_t* mapping = find_mapping_for_cluster(s, i);
+ /*
+ * Values will be negative for writes to the FAT, which is located before
+ * the root directory.
+ */
+ first_cluster = sector2cluster(s, sector_num);
+ last_cluster = sector2cluster(s, sector_num + nb_sectors - 1);
+
+ for (i = first_cluster; i <= last_cluster;) {
+ mapping_t *mapping = NULL;
+
+ if (i >= 0) {
+ mapping = find_mapping_for_cluster(s, i);
+ }
+
if (mapping) {
if (mapping->read_only) {
fprintf(stderr, "Tried to write to write-protected file %s\n",
@@ -3041,8 +3053,9 @@ DLOG(checkpoint());
}
}
i = mapping->end;
- } else
+ } else {
i++;
+ }
}
/*
@@ -3056,10 +3069,11 @@ DLOG(fprintf(stderr, "Write to qcow backend: %d + %d\n", (int)sector_num, nb_sec
return ret;
}
- for (i = sector2cluster(s, sector_num);
- i <= sector2cluster(s, sector_num + nb_sectors - 1); i++)
- if (i >= 0)
+ for (i = first_cluster; i <= last_cluster; i++) {
+ if (i >= 0) {
s->used_clusters[i] |= USED_ALLOCATED;
+ }
+ }
DLOG(checkpoint());
/* TODO: add timeout */