| /* |
| * Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank |
| * Copyright (c) 1995 Martin Husemann |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. All advertising materials mentioning features or use of this software |
| * must display the following acknowledgement: |
| * This product includes software developed by Martin Husemann |
| * and Wolfgang Solfrank. |
| * 4. Neither the name of the University nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| |
| #include <sys/cdefs.h> |
| #ifndef lint |
| __RCSID("$NetBSD: fat.c,v 1.12 2000/10/10 20:24:52 is Exp $"); |
| static const char rcsid[] = |
| "$FreeBSD: src/sbin/fsck_msdosfs/fat.c,v 1.9 2008/01/31 13:22:13 yar Exp $"; |
| #endif /* not lint */ |
| |
| #include <stdlib.h> |
| #include <string.h> |
| #include <ctype.h> |
| #include <stdio.h> |
| #include <unistd.h> |
| |
| #include "ext.h" |
| #include "fsutil.h" |
| |
| static int checkclnum(struct bootblock *, int, cl_t, cl_t *); |
| static int clustdiffer(cl_t, cl_t *, cl_t *, int); |
| static int tryclear(struct bootblock *, struct fatEntry *, cl_t, cl_t *); |
| static int _readfat(int, struct bootblock *, int, u_char **); |
| |
| /*- |
| * The first 2 FAT entries contain pseudo-cluster numbers with the following |
| * layout: |
| * |
| * 31...... ........ ........ .......0 |
| * rrrr1111 11111111 11111111 mmmmmmmm FAT32 entry 0 |
| * rrrrsh11 11111111 11111111 11111xxx FAT32 entry 1 |
| * |
| * 11111111 mmmmmmmm FAT16 entry 0 |
| * sh111111 11111xxx FAT16 entry 1 |
| * |
| * r = reserved |
| * m = BPB media ID byte |
| * s = clean flag (1 = dismounted; 0 = still mounted) |
| * h = hard error flag (1 = ok; 0 = I/O error) |
| * x = any value ok |
| */ |
| |
| int |
| checkdirty(int fs, struct bootblock *boot) |
| { |
| off_t off; |
| u_char *buffer; |
| int ret = 0; |
| |
| if (boot->ClustMask != CLUST16_MASK && boot->ClustMask != CLUST32_MASK) |
| return 0; |
| |
| off = boot->ResSectors; |
| off *= boot->BytesPerSec; |
| |
| buffer = malloc(boot->BytesPerSec); |
| if (buffer == NULL) { |
| perror("No space for FAT"); |
| return 1; |
| } |
| |
| if (lseek(fs, off, SEEK_SET) != off) { |
| perror("Unable to read FAT"); |
| goto err; |
| } |
| |
| if (read(fs, buffer, boot->BytesPerSec) != boot->BytesPerSec) { |
| perror("Unable to read FAT"); |
| goto err; |
| } |
| |
| /* |
| * If we don't understand the FAT, then the file system must be |
| * assumed to be unclean. |
| */ |
| if (buffer[0] != boot->Media || buffer[1] != 0xff) |
| goto err; |
| if (boot->ClustMask == CLUST16_MASK) { |
| if ((buffer[2] & 0xf8) != 0xf8 || (buffer[3] & 0x3f) != 0x3f) |
| goto err; |
| } else { |
| if (buffer[2] != 0xff || (buffer[3] & 0x0f) != 0x0f |
| || (buffer[4] & 0xf8) != 0xf8 || buffer[5] != 0xff |
| || buffer[6] != 0xff || (buffer[7] & 0x03) != 0x03) |
| goto err; |
| } |
| |
| /* |
| * Now check the actual clean flag (and the no-error flag). |
| */ |
| if (boot->ClustMask == CLUST16_MASK) { |
| if ((buffer[3] & 0xc0) == 0xc0) |
| ret = 1; |
| } else { |
| if ((buffer[7] & 0x0c) == 0x0c) |
| ret = 1; |
| } |
| |
| err: |
| free(buffer); |
| return ret; |
| } |
| |
| /* |
| * Check a cluster number for valid value |
| */ |
| static int |
| checkclnum(struct bootblock *boot, int fat, cl_t cl, cl_t *next) |
| { |
| if (*next >= (CLUST_RSRVD&boot->ClustMask)) |
| *next |= ~boot->ClustMask; |
| if (*next == CLUST_FREE) { |
| boot->NumFree++; |
| return FSOK; |
| } |
| if (*next == CLUST_BAD) { |
| boot->NumBad++; |
| return FSOK; |
| } |
| if (*next < CLUST_FIRST |
| || (*next >= boot->NumClusters && *next < CLUST_EOFS)) { |
| pwarn("Cluster %u in FAT %d continues with %s cluster number %u\n", |
| cl, fat, |
| *next < CLUST_RSRVD ? "out of range" : "reserved", |
| *next&boot->ClustMask); |
| if (ask(1, "Truncate")) { |
| *next = CLUST_EOF; |
| return FSFATMOD; |
| } |
| return FSERROR; |
| } |
| return FSOK; |
| } |
| |
| /* |
| * Read a FAT from disk. Returns 1 if successful, 0 otherwise. |
| */ |
| static int |
| _readfat(int fs, struct bootblock *boot, int no, u_char **buffer) |
| { |
| off_t off; |
| |
| printf("Attempting to allocate %u KB for FAT\n", |
| (boot->FATsecs * boot->BytesPerSec) / 1024); |
| |
| *buffer = malloc(boot->FATsecs * boot->BytesPerSec); |
| if (*buffer == NULL) { |
| perror("No space for FAT"); |
| return 0; |
| } |
| |
| off = boot->ResSectors + no * boot->FATsecs; |
| off *= boot->BytesPerSec; |
| |
| if (lseek(fs, off, SEEK_SET) != off) { |
| perror("Unable to read FAT"); |
| goto err; |
| } |
| |
| if (read(fs, *buffer, boot->FATsecs * boot->BytesPerSec) |
| != boot->FATsecs * boot->BytesPerSec) { |
| perror("Unable to read FAT"); |
| goto err; |
| } |
| |
| return 1; |
| |
| err: |
| free(*buffer); |
| return 0; |
| } |
| |
| /* |
| * Read a FAT and decode it into internal format |
| */ |
| int |
| readfat(int fs, struct bootblock *boot, int no, struct fatEntry **fp) |
| { |
| struct fatEntry *fat; |
| u_char *buffer, *p; |
| cl_t cl; |
| int ret = FSOK; |
| |
| boot->NumFree = boot->NumBad = 0; |
| |
| if (!_readfat(fs, boot, no, &buffer)) |
| return FSFATAL; |
| |
| fat = calloc(boot->NumClusters, sizeof(struct fatEntry)); |
| if (fat == NULL) { |
| perror("No space for FAT"); |
| free(buffer); |
| return FSFATAL; |
| } |
| |
| if (buffer[0] != boot->Media |
| || buffer[1] != 0xff || buffer[2] != 0xff |
| || (boot->ClustMask == CLUST16_MASK && buffer[3] != 0xff) |
| || (boot->ClustMask == CLUST32_MASK |
| && ((buffer[3]&0x0f) != 0x0f |
| || buffer[4] != 0xff || buffer[5] != 0xff |
| || buffer[6] != 0xff || (buffer[7]&0x0f) != 0x0f))) { |
| |
| /* Windows 95 OSR2 (and possibly any later) changes |
| * the FAT signature to 0xXXffff7f for FAT16 and to |
| * 0xXXffff0fffffff07 for FAT32 upon boot, to know that the |
| * file system is dirty if it doesn't reboot cleanly. |
| * Check this special condition before errorring out. |
| */ |
| if (buffer[0] == boot->Media && buffer[1] == 0xff |
| && buffer[2] == 0xff |
| && ((boot->ClustMask == CLUST16_MASK && buffer[3] == 0x7f) |
| || (boot->ClustMask == CLUST32_MASK |
| && buffer[3] == 0x0f && buffer[4] == 0xff |
| && buffer[5] == 0xff && buffer[6] == 0xff |
| && buffer[7] == 0x07))) |
| 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", |
| "FAT starts with odd byte sequence", |
| buffer[0], buffer[1], buffer[2], buffer[3], |
| buffer[4], buffer[5], buffer[6], buffer[7]); |
| break; |
| case CLUST16_MASK: |
| pwarn("%s (%02x%02x%02x%02x)\n", |
| "FAT starts with odd byte sequence", |
| buffer[0], buffer[1], buffer[2], buffer[3]); |
| break; |
| default: |
| pwarn("%s (%02x%02x%02x)\n", |
| "FAT starts with odd byte sequence", |
| buffer[0], buffer[1], buffer[2]); |
| break; |
| } |
| |
| |
| if (ask(1, "Correct")) |
| ret |= FSFIXFAT; |
| } |
| } |
| switch (boot->ClustMask) { |
| case CLUST32_MASK: |
| p = buffer + 8; |
| break; |
| case CLUST16_MASK: |
| p = buffer + 4; |
| break; |
| default: |
| p = buffer + 3; |
| break; |
| } |
| for (cl = CLUST_FIRST; cl < boot->NumClusters;) { |
| switch (boot->ClustMask) { |
| case CLUST32_MASK: |
| fat[cl].next = p[0] + (p[1] << 8) |
| + (p[2] << 16) + (p[3] << 24); |
| fat[cl].next &= boot->ClustMask; |
| ret |= checkclnum(boot, no, cl, &fat[cl].next); |
| cl++; |
| p += 4; |
| break; |
| case CLUST16_MASK: |
| fat[cl].next = p[0] + (p[1] << 8); |
| ret |= checkclnum(boot, no, cl, &fat[cl].next); |
| cl++; |
| p += 2; |
| break; |
| default: |
| fat[cl].next = (p[0] + (p[1] << 8)) & 0x0fff; |
| ret |= checkclnum(boot, no, cl, &fat[cl].next); |
| cl++; |
| if (cl >= boot->NumClusters) |
| break; |
| fat[cl].next = ((p[1] >> 4) + (p[2] << 4)) & 0x0fff; |
| ret |= checkclnum(boot, no, cl, &fat[cl].next); |
| cl++; |
| p += 3; |
| break; |
| } |
| } |
| |
| free(buffer); |
| *fp = fat; |
| return ret; |
| } |
| |
| /* |
| * Get type of reserved cluster |
| */ |
| char * |
| rsrvdcltype(cl_t cl) |
| { |
| if (cl == CLUST_FREE) |
| return "free"; |
| if (cl < CLUST_BAD) |
| return "reserved"; |
| if (cl > CLUST_BAD) |
| return "as EOF"; |
| return "bad"; |
| } |
| |
| static int |
| clustdiffer(cl_t cl, cl_t *cp1, cl_t *cp2, int fatnum) |
| { |
| if (*cp1 == CLUST_FREE || *cp1 >= CLUST_RSRVD) { |
| if (*cp2 == CLUST_FREE || *cp2 >= CLUST_RSRVD) { |
| if ((*cp1 != CLUST_FREE && *cp1 < CLUST_BAD |
| && *cp2 != CLUST_FREE && *cp2 < CLUST_BAD) |
| || (*cp1 > CLUST_BAD && *cp2 > CLUST_BAD)) { |
| pwarn("Cluster %u is marked %s with different indicators\n", |
| cl, rsrvdcltype(*cp1)); |
| if (ask(1, "Fix")) { |
| *cp2 = *cp1; |
| return FSFATMOD; |
| } |
| return FSFATAL; |
| } |
| pwarn("Cluster %u is marked %s in FAT 0, %s in FAT %d\n", |
| cl, rsrvdcltype(*cp1), rsrvdcltype(*cp2), fatnum); |
| if (ask(1, "Use FAT 0's entry")) { |
| *cp2 = *cp1; |
| return FSFATMOD; |
| } |
| if (ask(1, "Use FAT %d's entry", fatnum)) { |
| *cp1 = *cp2; |
| return FSFATMOD; |
| } |
| return FSFATAL; |
| } |
| pwarn("Cluster %u is marked %s in FAT 0, but continues with cluster %u in FAT %d\n", |
| cl, rsrvdcltype(*cp1), *cp2, fatnum); |
| if (ask(1, "Use continuation from FAT %d", fatnum)) { |
| *cp1 = *cp2; |
| return FSFATMOD; |
| } |
| if (ask(1, "Use mark from FAT 0")) { |
| *cp2 = *cp1; |
| return FSFATMOD; |
| } |
| return FSFATAL; |
| } |
| if (*cp2 == CLUST_FREE || *cp2 >= CLUST_RSRVD) { |
| pwarn("Cluster %u continues with cluster %u in FAT 0, but is marked %s in FAT %d\n", |
| cl, *cp1, rsrvdcltype(*cp2), fatnum); |
| if (ask(1, "Use continuation from FAT 0")) { |
| *cp2 = *cp1; |
| return FSFATMOD; |
| } |
| if (ask(1, "Use mark from FAT %d", fatnum)) { |
| *cp1 = *cp2; |
| return FSFATMOD; |
| } |
| return FSERROR; |
| } |
| pwarn("Cluster %u continues with cluster %u in FAT 0, but with cluster %u in FAT %d\n", |
| cl, *cp1, *cp2, fatnum); |
| if (ask(1, "Use continuation from FAT 0")) { |
| *cp2 = *cp1; |
| return FSFATMOD; |
| } |
| if (ask(1, "Use continuation from FAT %d", fatnum)) { |
| *cp1 = *cp2; |
| return FSFATMOD; |
| } |
| return FSERROR; |
| } |
| |
| /* |
| * Compare two FAT copies in memory. Resolve any conflicts and merge them |
| * into the first one. |
| */ |
| int |
| comparefat(struct bootblock *boot, struct fatEntry *first, |
| struct fatEntry *second, int fatnum) |
| { |
| cl_t cl; |
| int ret = FSOK; |
| |
| for (cl = CLUST_FIRST; cl < boot->NumClusters; cl++) |
| if (first[cl].next != second[cl].next) |
| ret |= clustdiffer(cl, &first[cl].next, &second[cl].next, fatnum); |
| return ret; |
| } |
| |
| void |
| clearchain(struct bootblock *boot, struct fatEntry *fat, cl_t head) |
| { |
| cl_t p, q; |
| |
| for (p = head; p >= CLUST_FIRST && p < boot->NumClusters; p = q) { |
| if (fat[p].head != head) |
| break; |
| q = fat[p].next; |
| fat[p].next = fat[p].head = CLUST_FREE; |
| fat[p].length = 0; |
| } |
| } |
| |
| int |
| tryclear(struct bootblock *boot, struct fatEntry *fat, cl_t head, cl_t *trunc) |
| { |
| if (ask(1, "Clear chain starting at %u", head)) { |
| clearchain(boot, fat, head); |
| return FSFATMOD; |
| } else if (ask(1, "Truncate")) { |
| *trunc = CLUST_EOF; |
| return FSFATMOD; |
| } else |
| return FSERROR; |
| } |
| |
| /* |
| * Check a complete FAT in-memory for crosslinks |
| */ |
| int |
| checkfat(struct bootblock *boot, struct fatEntry *fat) |
| { |
| cl_t head, p, h, n, wdk; |
| u_int len; |
| int ret = 0; |
| int conf; |
| |
| /* |
| * pass 1: figure out the cluster chains. |
| */ |
| for (head = CLUST_FIRST; head < boot->NumClusters; head++) { |
| /* find next untravelled chain */ |
| if (fat[head].head != 0 /* cluster already belongs to some chain */ |
| || fat[head].next == CLUST_FREE |
| || fat[head].next == CLUST_BAD) |
| continue; /* skip it. */ |
| |
| /* follow the chain and mark all clusters on the way */ |
| for (len = 0, p = head; |
| p >= CLUST_FIRST && p < boot->NumClusters; |
| p = fat[p].next) { |
| /* we have to check the len, to avoid infinite loop */ |
| if (len > boot->NumClusters) { |
| printf("detect cluster chain loop: head %u for p %u\n", head, p); |
| break; |
| } |
| |
| fat[p].head = head; |
| len++; |
| } |
| |
| /* the head record gets the length */ |
| fat[head].length = fat[head].next == CLUST_FREE ? 0 : len; |
| } |
| |
| /* |
| * pass 2: check for crosslinked chains (we couldn't do this in pass 1 because |
| * we didn't know the real start of the chain then - would have treated partial |
| * chains as interlinked with their main chain) |
| */ |
| for (head = CLUST_FIRST; head < boot->NumClusters; head++) { |
| /* find next untravelled chain */ |
| if (fat[head].head != head) |
| continue; |
| |
| /* follow the chain to its end (hopefully) */ |
| /* also possible infinite loop, that's why I insert wdk counter */ |
| for (p = head,wdk=boot->NumClusters; |
| (n = fat[p].next) >= CLUST_FIRST && n < boot->NumClusters && wdk; |
| p = n,wdk--) { |
| if (fat[n].head != head) |
| break; |
| } |
| |
| if (n >= CLUST_EOFS) |
| continue; |
| |
| if (n == CLUST_FREE || n >= CLUST_RSRVD) { |
| pwarn("Cluster chain starting at %u ends with cluster marked %s\n", |
| head, rsrvdcltype(n)); |
| 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; |
| } |
| pwarn("Cluster chains starting at %u and %u are linked at cluster %u\n", |
| head, fat[n].head, n); |
| conf = tryclear(boot, fat, head, &fat[p].next); |
| if (ask(1, "Clear chain starting at %u", h = fat[n].head)) { |
| if (conf == FSERROR) { |
| /* |
| * Transfer the common chain to the one not cleared above. |
| */ |
| for (p = n; |
| p >= CLUST_FIRST && p < boot->NumClusters; |
| p = fat[p].next) { |
| if (h != fat[p].head) { |
| /* |
| * Have to reexamine this chain. |
| */ |
| head--; |
| break; |
| } |
| fat[p].head = head; |
| } |
| } |
| clearchain(boot, fat, h); |
| conf |= FSFATMOD; |
| } |
| ret |= conf; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Write out FATs encoding them from the internal format |
| */ |
| int |
| writefat(int fs, struct bootblock *boot, struct fatEntry *fat, int correct_fat) |
| { |
| u_char *buffer, *p; |
| cl_t cl; |
| int i; |
| u_int32_t fatsz; |
| off_t off; |
| int ret = FSOK; |
| |
| buffer = malloc(fatsz = boot->FATsecs * boot->BytesPerSec); |
| if (buffer == NULL) { |
| perror("No space for FAT"); |
| return FSFATAL; |
| } |
| memset(buffer, 0, fatsz); |
| boot->NumFree = 0; |
| p = buffer; |
| if (correct_fat) { |
| *p++ = (u_char)boot->Media; |
| *p++ = 0xff; |
| *p++ = 0xff; |
| switch (boot->ClustMask) { |
| case CLUST16_MASK: |
| *p++ = 0xff; |
| break; |
| case CLUST32_MASK: |
| *p++ = 0x0f; |
| *p++ = 0xff; |
| *p++ = 0xff; |
| *p++ = 0xff; |
| *p++ = 0x0f; |
| break; |
| } |
| } else { |
| /* use same FAT signature as the old FAT has */ |
| int count; |
| u_char *old_fat; |
| |
| switch (boot->ClustMask) { |
| case CLUST32_MASK: |
| count = 8; |
| break; |
| case CLUST16_MASK: |
| count = 4; |
| break; |
| default: |
| count = 3; |
| break; |
| } |
| |
| if (!_readfat(fs, boot, boot->ValidFat >= 0 ? boot->ValidFat :0, |
| &old_fat)) { |
| free(buffer); |
| return FSFATAL; |
| } |
| |
| memcpy(p, old_fat, count); |
| free(old_fat); |
| p += count; |
| } |
| |
| for (cl = CLUST_FIRST; cl < boot->NumClusters; cl++) { |
| switch (boot->ClustMask) { |
| case CLUST32_MASK: |
| if (fat[cl].next == CLUST_FREE) |
| boot->NumFree++; |
| *p++ = (u_char)fat[cl].next; |
| *p++ = (u_char)(fat[cl].next >> 8); |
| *p++ = (u_char)(fat[cl].next >> 16); |
| *p &= 0xf0; |
| *p++ |= (fat[cl].next >> 24)&0x0f; |
| break; |
| case CLUST16_MASK: |
| if (fat[cl].next == CLUST_FREE) |
| boot->NumFree++; |
| *p++ = (u_char)fat[cl].next; |
| *p++ = (u_char)(fat[cl].next >> 8); |
| break; |
| 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); |
| break; |
| } |
| } |
| for (i = 0; i < boot->FATs; i++) { |
| off = boot->ResSectors + i * boot->FATsecs; |
| off *= boot->BytesPerSec; |
| if (lseek(fs, off, SEEK_SET) != off |
| || write(fs, buffer, fatsz) != fatsz) { |
| perror("Unable to write FAT"); |
| ret = FSFATAL; /* Return immediately? XXX */ |
| } |
| } |
| free(buffer); |
| return ret; |
| } |
| |
| /* |
| * Check a complete in-memory FAT for lost cluster chains |
| */ |
| int |
| 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 |
| || fat[head].next == CLUST_FREE |
| || (fat[head].next >= CLUST_RSRVD |
| && fat[head].next < CLUST_EOFS) |
| || (fat[head].flags & FAT_USED)) |
| continue; |
| |
| pwarn("Lost cluster chain at cluster %u\n%d Cluster(s) lost\n", |
| head, fat[head].length); |
| mod |= ret = reconnect(dosfs, boot, fat, head); |
| if (mod & FSFATAL) { |
| /* If the reconnect failed, then just clear the chain */ |
| pwarn("Error reconnecting chain - clearing\n"); |
| mod &= ~FSFATAL; |
| clearchain(boot, fat, head); |
| mod |= FSFATMOD; |
| continue; |
| } |
| if (ret == FSERROR && ask(1, "Clear")) { |
| clearchain(boot, fat, head); |
| mod |= FSFATMOD; |
| } |
| } |
| finishlf(); |
| |
| if (boot->FSInfo) { |
| ret = 0; |
| if (boot->FSFree != boot->NumFree) { |
| pwarn("Free space in FSInfo block (%d) not correct (%d)\n", |
| boot->FSFree, boot->NumFree); |
| if (ask(1, "Fix")) { |
| boot->FSFree = boot->NumFree; |
| ret = 1; |
| } |
| } |
| |
| if (boot->NumFree) { |
| if ((boot->FSNext >= boot->NumClusters) || (fat[boot->FSNext].next != CLUST_FREE)) { |
| pwarn("Next free cluster in FSInfo block (%u) not free\n", |
| boot->FSNext); |
| if (ask(1, "Fix")) |
| for (head = CLUST_FIRST; head < boot->NumClusters; head++) |
| if (fat[head].next == CLUST_FREE) { |
| boot->FSNext = head; |
| ret = 1; |
| break; |
| } |
| } |
| } |
| |
| if (boot->FSNext > boot->NumClusters ) { |
| pwarn("FSNext block (%d) not correct NumClusters (%d)\n", |
| boot->FSNext, boot->NumClusters); |
| boot->FSNext=CLUST_FIRST; // boot->FSNext can have -1 value. |
| } |
| |
| if (boot->NumFree && fat[boot->FSNext].next != CLUST_FREE) { |
| pwarn("Next free cluster in FSInfo block (%u) not free\n", |
| boot->FSNext); |
| if (ask(1, "Fix")) |
| for (head = CLUST_FIRST; head < boot->NumClusters; head++) |
| if (fat[head].next == CLUST_FREE) { |
| boot->FSNext = head; |
| ret = 1; |
| break; |
| } |
| } |
| |
| if (ret) |
| mod |= writefsinfo(dosfs, boot); |
| } |
| |
| return mod; |
| } |