diff options
| -rw-r--r-- | block/vvfat.c | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/block/vvfat.c b/block/vvfat.c index 36e73d4c64..b2b58d93b8 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -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 */ |