diff options
Diffstat (limited to 'sbin/fsck_msdosfs/fat.c')
| -rw-r--r-- | sbin/fsck_msdosfs/fat.c | 52 |
1 files changed, 35 insertions, 17 deletions
diff --git a/sbin/fsck_msdosfs/fat.c b/sbin/fsck_msdosfs/fat.c index d2d1444..b509c50 100644 --- a/sbin/fsck_msdosfs/fat.c +++ b/sbin/fsck_msdosfs/fat.c @@ -242,7 +242,7 @@ readfat(int fs, struct bootblock *boot, u_int no, struct fatEntry **fp) ret |= FSDIRTY; else { /* just some odd byte sequence in FAT */ - + switch (boot->ClustMask) { case CLUST32_MASK: pwarn("%s (%02x%02x%02x%02x%02x%02x%02x%02x)\n", @@ -262,7 +262,7 @@ readfat(int fs, struct bootblock *boot, u_int no, struct fatEntry **fp) break; } - + if (ask(1, "Correct")) ret |= FSFIXFAT; } @@ -436,7 +436,15 @@ tryclear(struct bootblock *boot, struct fatEntry *fat, cl_t head, cl_t *truncp) clearchain(boot, fat, head); return FSFATMOD; } else if (ask(0, "Truncate")) { + uint32_t len; + cl_t p; + + for (p = head, len = 0; + p >= CLUST_FIRST && p < boot->NumClusters; + p = fat[p].next, len++) + continue; *truncp = CLUST_EOF; + fat[head].length = len; return FSFATMOD; } else return FSERROR; @@ -465,7 +473,8 @@ checkfat(struct bootblock *boot, struct fatEntry *fat) /* follow the chain and mark all clusters on the way */ for (len = 0, p = head; - p >= CLUST_FIRST && p < boot->NumClusters; + p >= CLUST_FIRST && p < boot->NumClusters && + fat[p].head != head; p = fat[p].next) { fat[p].head = head; len++; @@ -486,10 +495,10 @@ checkfat(struct bootblock *boot, struct fatEntry *fat) continue; /* follow the chain to its end (hopefully) */ - for (p = head; + for (len = fat[head].length, p = head; (n = fat[p].next) >= CLUST_FIRST && n < boot->NumClusters; p = n) - if (fat[n].head != head) + if (fat[n].head != head || len-- < 2) break; if (n >= CLUST_EOFS) continue; @@ -497,14 +506,20 @@ checkfat(struct bootblock *boot, struct fatEntry *fat) if (n == CLUST_FREE || n >= CLUST_RSRVD) { pwarn("Cluster chain starting at %u ends with cluster marked %s\n", head, rsrvdcltype(n)); +clear: ret |= tryclear(boot, fat, head, &fat[p].next); continue; } if (n < CLUST_FIRST || n >= boot->NumClusters) { pwarn("Cluster chain starting at %u ends with cluster out of range (%u)\n", - head, n); - ret |= tryclear(boot, fat, head, &fat[p].next); - continue; + head, n); + goto clear; + } + if (head == fat[n].head) { + pwarn("Cluster chain starting at %u loops at cluster %u\n", + + head, p); + goto clear; } pwarn("Cluster chains starting at %u and %u are linked at cluster %u\n", head, fat[n].head, n); @@ -621,13 +636,15 @@ writefat(int fs, struct bootblock *boot, struct fatEntry *fat, int correct_fat) default: if (fat[cl].next == CLUST_FREE) boot->NumFree++; - if (cl + 1 < boot->NumClusters - && fat[cl + 1].next == CLUST_FREE) - boot->NumFree++; *p++ = (u_char)fat[cl].next; - *p++ = (u_char)((fat[cl].next >> 8) & 0xf) - |(u_char)(fat[cl+1].next << 4); - *p++ = (u_char)(fat[++cl].next >> 4); + *p = (u_char)((fat[cl].next >> 8) & 0xf); + cl++; + if (cl >= boot->NumClusters) + break; + if (fat[cl].next == CLUST_FREE) + boot->NumFree++; + *p++ |= (u_char)(fat[cl + 1].next << 4); + *p++ = (u_char)(fat[cl + 1].next >> 4); break; } } @@ -653,7 +670,7 @@ checklost(int dosfs, struct bootblock *boot, struct fatEntry *fat) cl_t head; int mod = FSOK; int ret; - + for (head = CLUST_FIRST; head < boot->NumClusters; head++) { /* find next untravelled chain */ if (fat[head].head != head @@ -677,8 +694,9 @@ checklost(int dosfs, struct bootblock *boot, struct fatEntry *fat) if (boot->bpbFSInfo) { ret = 0; - if (boot->FSFree != boot->NumFree) { - pwarn("Free space in FSInfo block (%d) not correct (%d)\n", + if (boot->FSFree != 0xffffffffU && + boot->FSFree != boot->NumFree) { + pwarn("Free space in FSInfo block (%u) not correct (%u)\n", boot->FSFree, boot->NumFree); if (ask(1, "Fix")) { boot->FSFree = boot->NumFree; |
