| /* |
| * 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/types.h> |
| #include <sys/stat.h> |
| #include <fcntl.h> |
| #include <sys/cdefs.h> |
| #include <assert.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" |
| #include "fatcache.h" |
| #include "fragment.h" |
| static int checkclnum(struct bootblock *, cl_t, cl_t *); |
| static int clustdiffer(cl_t, cl_t *, cl_t *, int,int *); |
| static int tryclear(struct bootblock* ,struct cluster_chain_descriptor *, cl_t, cl_t *); |
| int _readfat(int, struct bootblock *, int, u_char **); |
| |
| static cl_t firstfreecl = 0xFFFFFFFF; |
| /*- |
| * 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 struct fragment *lastfree= NULL; |
| static struct fragment *lastbad= NULL; |
| int checkclnum(struct bootblock *boot, cl_t cl, cl_t *next) |
| { |
| struct fragment *frag; |
| struct fragment *insert; |
| if((*next >= (CLUST_EOFS & boot->ClustMask)) && (*next <= (CLUST_EOF & boot->ClustMask))) |
| return FSOK; |
| if(*next >= (CLUST_RSRVD & boot->ClustMask)){ |
| *next |= ~boot->ClustMask; |
| } |
| /*if it is a free cluster,add to rb_free_root tree*/ |
| if (*next == CLUST_FREE) { |
| boot->NumFree++; |
| /*find the first free cluster ,this value will be used to update fsinfo*/ |
| if(firstfreecl > cl) |
| firstfreecl = cl; |
| if(lastfree){ |
| if( cl == (lastfree->head + lastfree->length)){ |
| lastfree->length += 1; |
| return FSOK; |
| } |
| } |
| frag = New_fragment(); |
| if(!frag){ |
| fsck_info("No space \n"); |
| return FSERROR; |
| } |
| frag->head = cl; |
| frag->length = 1; |
| insert = RB_INSERT(FSCK_MSDOS_FRAGMENT,&rb_free_root,frag); |
| if(insert){ |
| fsck_info("%s:fragment(head:0x%x) exist\n",__func__,frag->head); |
| return FSERROR; |
| } |
| lastfree = frag; |
| return FSOK; |
| } |
| /*if it is a bad cluster ,add to rb_bad_root tree*/ |
| if (*next == CLUST_BAD) { |
| boot->NumBad++; |
| if(lastbad){ |
| if(cl == (lastbad->head + lastbad->length)){ |
| lastbad->length += 1; |
| return FSOK; |
| } |
| } |
| frag = New_fragment(); |
| if(!frag){ |
| fsck_info("No Space\n"); |
| return FSERROR; |
| } |
| frag->head = cl; |
| frag->length = 1; |
| insert = RB_INSERT(FSCK_MSDOS_FRAGMENT,&rb_bad_root,frag); |
| if(insert){ |
| fsck_info("%s:fragment(head:0x%x) exist\n",__func__,frag->head); |
| return FSERROR; |
| } |
| lastbad = frag; |
| return FSOK; |
| } |
| if (*next < CLUST_FIRST || (*next >= boot->NumClusters && *next < (CLUST_EOFS & boot->ClustMask))) { |
| pwarn("Cluster %u in FAT continues with %s cluster number %u\n", |
| cl, |
| *next < CLUST_RSRVD ? "out of range" : "reserved", |
| *next&boot->ClustMask); |
| if (ask(1, "Truncate")) { |
| /*do nothing about truncate*/ |
| return FSFATMOD; |
| } |
| return FSERROR; |
| } |
| return FSOK; |
| } |
| |
| /* |
| * Read a FAT from disk. Returns 1 if successful, 0 otherwise. |
| */ |
| 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 |
| */ |
| unsigned int *fat_bitmap; |
| int checkfat(int fs, struct bootblock *boot, int no,u_char *buffer) |
| { |
| struct cluster_chain_descriptor *fat = NULL,*nextcl_fat,*insert,*remove,tofind; |
| struct fatcache *cache = NULL; |
| u_char *p; |
| cl_t cl,prevcl = 0, nextclus; |
| int len = 0; |
| int ret = FSOK,err = 0; |
| boot->NumFree = boot->NumBad = 0; |
| fat_bitmap = calloc(boot->NumClusters/32+1,sizeof(unsigned int)); |
| if(!fat_bitmap){ |
| fsck_err("NO space left\n"); |
| 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; |
| } |
| } |
| fsck_info("Begin to handle the cluster chain\n"); |
| for (cl = CLUST_FIRST; cl < boot->NumClusters;cl++) { |
| /*have handled it by cluster chain*/ |
| if(BIT(fat_bitmap[cl/32],cl%32)) |
| continue; |
| prevcl = nextclus = cl; |
| len = 0; |
| switch (boot->ClustMask) { |
| case CLUST32_MASK: |
| p = buffer + 4*cl; |
| break; |
| case CLUST16_MASK: |
| p = buffer + 2*cl; |
| break; |
| default: |
| p = buffer + 3*(cl/2); |
| break; |
| } |
| while(nextclus >= CLUST_FIRST && nextclus < boot->NumClusters){ |
| |
| switch (boot->ClustMask) { |
| case CLUST32_MASK: |
| nextclus = p[0] + (p[1] << 8) |
| + (p[2] << 16) + (p[3] << 24); |
| nextclus &= boot->ClustMask; |
| p = buffer + 4*nextclus; |
| break; |
| case CLUST16_MASK: |
| nextclus = p[0] + (p[1] << 8); |
| p = buffer + 2*nextclus; |
| break; |
| /*FAT12 is special*/ |
| default: |
| /* odd */ |
| if(!(nextclus & 0x1)) |
| nextclus = (p[0] + (p[1] << 8)) & 0x0fff; |
| else |
| nextclus = ((p[1] >> 4) + (p[2] << 4)) & 0x0fff; |
| p = buffer + 3*(nextclus/2); |
| break; |
| } |
| err = checkclnum(boot,prevcl,&nextclus); |
| ret |= err; |
| if(err & FSERROR) |
| return -1; |
| //truncate the rest clusters |
| if(err & FSFATMOD) |
| break; |
| len++; |
| /* |
| *TODO:because this cluster chain is special,such as |
| *fatentry->fatcache->fatcache->fatcache->NULL |
| *so you should treat the first fatcache specially |
| */ |
| if(len == 1){ |
| if(nextclus == CLUST_FREE || nextclus == CLUST_BAD ){ |
| SET_BIT(fat_bitmap[prevcl/32],prevcl%32); |
| break; |
| } |
| } |
| /*last cluster*/ |
| if((nextclus >= (CLUST_EOFS & boot->ClustMask)) && (nextclus <= (CLUST_EOF & boot->ClustMask)) && (len != 1)){ |
| SET_BIT(fat_bitmap[prevcl/32],prevcl%32); |
| break; |
| } |
| /*rsrvd*/ |
| if(nextclus == CLUST_FREE || ((nextclus >= (CLUST_RSRVD & boot->ClustMask)) && (nextclus < (CLUST_EOFS & boot->ClustMask)))){ |
| fsck_warn("Cluster chain starting at %u ends with cluster marked %s,cl = %d ,nextclus = %d\n",cl,rsrvdcltype(nextclus),cl,nextclus); |
| SET_BIT(fat_bitmap[prevcl/32],prevcl%32); |
| /*if the next cluster is free or reversed ,just clear the existing cluster chain ,let this free or reversed cluster alone*/ |
| ret |= tryclear(boot,fat,cl,&prevcl); |
| break; |
| } |
| /*out of range*/ |
| if(nextclus < CLUST_FIRST ||(( nextclus >= boot->NumClusters) && (nextclus < (CLUST_EOFS & boot->ClustMask)))){ |
| fsck_warn("Clusters chain starting at %u ends with cluster out of range (%u) \n",cl,nextclus); |
| SET_BIT(fat_bitmap[prevcl/32],prevcl%32); |
| ret |= tryclear(boot,fat,cl,&prevcl); |
| break; |
| } |
| |
| if((nextclus >= CLUST_FIRST && nextclus < boot->NumClusters)&& BIT(fat_bitmap[nextclus/32],nextclus%32)){ |
| /* |
| *it is interesting,because 0x3->0x34->0x35->EOF,then you find 0x100->0x3. |
| *it is right here,must merge them |
| */ |
| tofind.head = nextclus; |
| nextcl_fat = RB_FIND(FSCK_MSDOS_CACHE,&rb_root,&tofind); |
| /*if nextcl_fat == fat ,unfortunately ,it is a cluster loop,such as 0x2->0x3->0x4->0x2*/ |
| if(nextcl_fat && (nextcl_fat != fat)){ |
| if(len == 1){ |
| /*the first one ,you should malloc both fatEntry and fatcache*/ |
| fat = New_fatentry(); |
| if(!fat) |
| return FSFATAL; |
| fat->head = prevcl; |
| fat->length = 1; |
| /* |
| *i was puzzled whether check the pointer insert here |
| *if some error,there is a exsting fatentry in rb tree.NOT check maybe a good choice |
| */ |
| insert = RB_INSERT(FSCK_MSDOS_CACHE,&rb_root,fat); |
| if(insert){ |
| fsck_err("%s:fatentry(head:0x%x) exist\n",__func__,fat->head); |
| return FSFATAL; |
| } |
| cache = New_fatcache(); |
| if(!cache) |
| return FSFATAL; |
| cache->head = prevcl; |
| cache->length = 1; |
| err = add_fatcache_To_ClusterChain(fat,cache); |
| if(err){ |
| fsck_err("add_fatcache_To_ClusterChain ,err = %d \n",err); |
| return FSFATAL; |
| } |
| /*merge nextcl_fat chain to new one*/ |
| cache->next = nextcl_fat->child; |
| fat->length += nextcl_fat->length; |
| }else{ |
| /* |
| *we use fat directly here,after handling a cluster chain ,must set fat = NULL, |
| *otherwise ,the fat is prev cluster chain |
| */ |
| add_fatcache_Totail(fat,nextcl_fat->child); |
| fat->length += nextcl_fat->length; |
| } |
| nextcl_fat->child = NULL; |
| /*now delete nextcl_fat entry ,because have merge its child to fat*/ |
| remove = RB_REMOVE(FSCK_MSDOS_CACHE,&rb_root,nextcl_fat); |
| free(nextcl_fat); |
| SET_BIT(fat_bitmap[prevcl/32],prevcl%32); |
| break; |
| } |
| /* |
| *it is very complex here,if a cluster has been handled ,but it is not a head of a cluster chain,there are some cases: |
| *case 1:Due to some error ,this cluster has been removed from rb tree by tryclear() |
| *case 2:clsuter chains linked |
| *case 3:cluster loop |
| *whatever ,i think tryclear() is a simplest solution |
| */ |
| fsck_err("Cluster chian is wrong\n"); |
| Dump_fatentry(fat); |
| Dump_fatentry(nextcl_fat); |
| /*sometimes ,fat == NULL here,it means this cluster chain haven't be insert to rb tree,ok,do nothing here*/ |
| if(!fat) |
| break; |
| if(ask(1,"Clear chain starting at %u",nextclus)){ |
| /* |
| *compare with orginal code,i delete some codes here |
| *because i handle fat chain by chain here, |
| *it never appear situation that three or more cluster chains linked |
| */ |
| ret |= tryclear(boot,fat,cl,&prevcl); |
| break; |
| } |
| } |
| /*it is a legal cluster ,add it*/ |
| SET_BIT(fat_bitmap[prevcl/32],prevcl%32); |
| if(len == 1){ |
| /*TODO: |
| *that is the first cluster of this legal chain |
| *it is special ,normally, we just add nextcluster to chain |
| *but if it is first one ,we must add both two. |
| */ |
| fat = New_fatentry(); |
| if(!fat){ |
| fsck_err("No space \n"); |
| return FSFATAL; |
| } |
| fat->head = cl; |
| insert = RB_INSERT(FSCK_MSDOS_CACHE,&rb_root,fat); |
| if(insert){ |
| fsck_err("%s:fatentry(head:0x%x) exist\n",__func__,fat->head); |
| return FSFATAL; |
| } |
| cache = New_fatcache(); |
| if(!cache){ |
| fsck_err("No space \n"); |
| return FSFATAL; |
| } |
| cache->head = prevcl; |
| cache->length = 1; |
| err = add_fatcache_To_ClusterChain(fat,cache); |
| if(err){ |
| fsck_err("add_fatcache_To_ClusterChain ,err = %d \n",err); |
| } |
| if(nextclus >= (CLUST_EOFS & boot->ClustMask) && nextclus <= (CLUST_EOF & boot->ClustMask)){ |
| break; |
| } |
| if(prevcl + 1 == nextclus){ |
| cache->length += 1; |
| fat->length += 1; |
| prevcl = nextclus; |
| continue; |
| }else{ |
| cache = New_fatcache(); |
| if(!cache){ |
| fsck_err("No space\n"); |
| return FSFATAL; |
| } |
| cache->head = nextclus; |
| cache->length = 1; |
| err = add_fatcache_To_ClusterChain(fat,cache); |
| if(err){ |
| fsck_err("add_fatcache_To_ClusterChain ,err = %d \n",err); |
| } |
| } |
| }else{ |
| if(nextclus >= (CLUST_EOFS & boot->ClustMask) && nextclus <= (CLUST_EOF & boot->ClustMask)){ |
| break; |
| } |
| if( prevcl + 1 == nextclus){ |
| /*if it is continuous ,just modify the length*/ |
| cache->length += 1; |
| fat->length += 1; |
| }else{ |
| cache = New_fatcache(); |
| if(!cache){ |
| fsck_err("No Space\n"); |
| return FSFATAL; |
| } |
| cache->head = nextclus; |
| cache->length = 1; |
| err = add_fatcache_To_ClusterChain(fat,cache); |
| if(err){ |
| fsck_err("add_fatcache_To_ClusterChain ,err = %d \n",err); |
| } |
| } |
| } |
| prevcl = nextclus; |
| } |
| /*set fat = NULL,otherwise this fat pointer will impact the next process*/ |
| fat = NULL; |
| } |
| #if 0 |
| fsck_info("Dump cluster chains\n"); |
| RB_FOREACH(fat, FSCK_MSDOS_CACHE,&rb_root){ |
| fsck_info("head:0x%x:length:0x%x\n",fat->head,fat->length); |
| } |
| #endif |
| free(fat_bitmap); |
| 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"; |
| } |
| /* |
| *if *res = 1,that means *cp1 = *cp2 |
| *if *res = 0 ,means *cp2 = *cp1; |
| */ |
| static int |
| clustdiffer(cl_t cl, cl_t *cp1, cl_t *cp2, int fatnum, int *res) |
| { |
| fsck_debug("clustdiff:%u : %u \n",*cp1,*cp2); |
| 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")) { |
| *res = 0; |
| 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")) { |
| *res = 0; |
| return FSFATMOD; |
| } |
| if (ask(1, "Use FAT %d's entry", fatnum)) { |
| *res = 1; |
| 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)) { |
| *res = 1; |
| return FSFATMOD; |
| } |
| if (ask(1, "Use mark from FAT 0")) { |
| *res = 0; |
| 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")) { |
| *res = 0; |
| return FSFATMOD; |
| } |
| if (ask(1, "Use mark from FAT %d", fatnum)) { |
| *res = 1; |
| 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")) { |
| *res = 0; |
| return FSFATMOD; |
| } |
| if (ask(1, "Use continuation from FAT %d", fatnum)) { |
| *res = 1; |
| 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, u_char*first, u_char *second, int fatnum) |
| { |
| cl_t cl; |
| u_char *sp,*fp,*wp; |
| int ret = FSOK,res = 0; |
| cl_t first_cl,second_cl,w_cl; |
| fsck_info("Begin to compare FAT\n"); |
| for (cl = CLUST_FIRST; cl < boot->NumClusters; cl++){ |
| switch(boot->ClustMask){ |
| case CLUST32_MASK: |
| fp = first + 4*cl; |
| sp = second + 4*cl; |
| first_cl = (fp[0] + (fp[1]<<8) + (fp[2]<<16) + (fp[3]<<24)) & boot->ClustMask; |
| second_cl = (sp[0] + (sp[1]<<8) + (sp[2]<<16) + (sp[3]<<24)) & boot->ClustMask; |
| break; |
| |
| case CLUST16_MASK: |
| fp = first + 2*cl; |
| sp = second + 2*cl; |
| first_cl = (fp[0] + (fp[1] << 8)) & boot->ClustMask; |
| second_cl = (sp[0] + (sp[1] << 8)) & boot->ClustMask; |
| break; |
| |
| default: |
| fp = first + 3*(cl/2); |
| sp = second + 3*(cl/2); |
| if(cl & 0x1){ |
| first_cl = ((fp[1]>>4) + (fp[2]<<4)) & 0x0fff; |
| second_cl = ((sp[1]>>4) + (sp[2]<<4)) & 0x0fff; |
| }else{ |
| first_cl = (fp[0] + (fp[1] << 8)) & 0x0fff; |
| second_cl = (sp[0] + (sp[1] << 8)) & 0x0fff; |
| } |
| break; |
| } |
| if(first_cl == second_cl) |
| continue; |
| fsck_warn("%u is not same(%u ; %u)\n",cl,first_cl,second_cl); |
| ret |= clustdiffer(cl, &first_cl,&second_cl, fatnum,&res); |
| if(res){ |
| wp = fp; |
| w_cl = second_cl; |
| }else{ |
| wp = sp; |
| w_cl = first_cl; |
| } |
| /* fisrt_cl = second_cl */ |
| switch(boot->ClustMask){ |
| case CLUST32_MASK: |
| *wp++ = (u_char)w_cl; |
| *wp++ = (u_char)(w_cl >>8); |
| *wp++ = (u_char)(w_cl >> 16); |
| *wp &= 0xf0; |
| *wp |= (w_cl >>24) &0x0f; |
| break; |
| |
| case CLUST16_MASK: |
| *wp++ = (u_char)w_cl; |
| *wp = (u_char)(w_cl >> 8); |
| break; |
| |
| default: |
| if(cl & 0x1){ |
| /* wp[1] ,wp[2]*/ |
| wp++; |
| *wp++ |= (u_char)((w_cl << 4) & 0xf0); |
| *wp = (u_char)(w_cl >> 4); |
| }else{ |
| /* wp[0] ,wp[1]*/ |
| *wp++ = (u_char)w_cl; |
| *wp |= (u_char)((w_cl >> 8) & 0x0f); |
| } |
| break; |
| } |
| } |
| return ret; |
| } |
| |
| void |
| clearchain(struct bootblock *boot,struct cluster_chain_descriptor *fat, cl_t head) |
| { |
| struct fatcache * curr,*next; |
| struct fragment *frag, *insert; |
| |
| fsck_debug("%s:fat:%p , head(%d) ,length(%d)\n",__func__,fat,fat->head,fat->length); |
| assert(fat); |
| if(fat->head != head) |
| return; |
| /*re-calc free blocks*/ |
| boot->NumFree += fat->length; |
| /*move to free tree for writefat()*/ |
| curr = fat->child; |
| while(curr){ |
| next = curr->next; |
| frag = New_fragment(); |
| if(!frag){ |
| fsck_warn("%s: No space left\n",__func__); |
| goto free; |
| } |
| frag->head = curr->head; |
| frag->length = curr->length; |
| insert = RB_INSERT(FSCK_MSDOS_FRAGMENT,&rb_free_root,frag); |
| if(insert) |
| fsck_warn("%s:fragment(head:0x%x) exist\n",__func__,frag->head); |
| free: |
| free(curr); |
| curr = next; |
| } |
| /*must remove from rb tree before free*/ |
| RB_REMOVE(FSCK_MSDOS_CACHE,&rb_root,fat); |
| free(fat); |
| } |
| |
| int |
| tryclear(struct bootblock* boot, struct cluster_chain_descriptor *fat, cl_t head, cl_t *trunc) |
| { |
| fsck_debug("fat:%p ,head :%d ,trunc :%d \n",fat,head,*trunc); |
| if(!fat || !trunc){ |
| pwarn("%s :null pointer\n",__func__); |
| return FSERROR; |
| } |
| if (ask(1, "Clear chain starting at %u", head)) { |
| clearchain(boot,fat, head); |
| return FSFATMOD; |
| } else if (ask(1, "Truncate")) { |
| Trunc(boot,fat,*trunc); |
| return FSFATMOD; |
| } else |
| return FSERROR; |
| } |
| |
| /* |
| * Write out FATs encoding them from the internal format |
| */ |
| int |
| writefat(int fs, struct bootblock *boot, int correct_fat) |
| { |
| u_char *buffer, *p; |
| cl_t cl; |
| unsigned int i; |
| u_int32_t fatsz; |
| off_t off; |
| int ret = FSOK; |
| struct cluster_chain_descriptor *fat; |
| struct fatcache* cache,*next_cache; |
| struct fragment *frag; |
| fsck_debug("begin to writefat \n"); |
| buffer = malloc(fatsz = boot->FATsecs * boot->BytesPerSec); |
| if (buffer == NULL) { |
| perror("No space for FAT"); |
| return FSFATAL; |
| } |
| memset(buffer, 0, fatsz); |
| 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; |
| } |
| |
| fsck_info("begin to write FAT\n"); |
| fat = RB_MIN(FSCK_MSDOS_CACHE,&rb_root); |
| if(!fat){ |
| fsck_info("%s:rb tree is empty\n",__func__); |
| return FSFATAL; |
| } |
| fsck_info("write valid cluster chain\n"); |
| while(fat){ |
| cache = fat->child; |
| while(cache){ |
| cl = cache->head; |
| for( i = 0 ; i < (cache->length - 1);i++) |
| SetNextClusToFAT(boot,buffer,cl+i ,cl+i+1); |
| next_cache = cache->next; |
| if(next_cache) |
| SetNextClusToFAT(boot,buffer,cl+cache->length -1,next_cache->head); |
| else |
| SetNextClusToFAT(boot,buffer,cl+cache->length -1,CLUST_EOF); |
| cache = next_cache; |
| } |
| fat = RB_NEXT(FSCK_MSDOS_CACHE,0,fat); |
| } |
| /*the FreeNumber may be not correct*/ |
| fsck_info("write free cluster\n"); |
| RB_FOREACH(frag, FSCK_MSDOS_FRAGMENT,&rb_free_root){ |
| cl = frag->head; |
| for(i = 0 ; i < frag->length ;i++) |
| SetNextClusToFAT(boot,buffer,cl+i ,CLUST_FREE); |
| } |
| fsck_info("write bad cluster\n"); |
| RB_FOREACH(frag, FSCK_MSDOS_FRAGMENT,&rb_bad_root){ |
| cl = frag->head; |
| for(i = 0 ; i < frag->length ;i++) |
| SetNextClusToFAT(boot,buffer,cl+i ,CLUST_BAD); |
| } |
| fsck_debug("write FATs\n"); |
| for (i = 0; i < boot->FATs; i++) { |
| fsck_debug("write FAT copy %d \n",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) |
| { |
| int mod = FSOK; |
| int ret; |
| struct cluster_chain_descriptor *fat, *next; |
| fat = RB_MIN(FSCK_MSDOS_CACHE,&rb_root); |
| if(!fat){ |
| fsck_info("%s:rb_root tree is empty\n",__func__); |
| //After format FAT16,nothing left |
| if(boot->ClustMask & CLUST16_MASK) |
| return FSOK; |
| else |
| return FSFATAL; |
| } |
| while(fat){ |
| if(fat->flag & FAT_USED){ |
| fat = RB_NEXT(FSCK_MSDOS_CACHE,0,fat); |
| continue; |
| } |
| fsck_info("Lost cluster chain at head %u ,%d Cluster(s) lost\n",fat->head, fat->length); |
| mod |= ret = reconnect(dosfs, boot,fat, fat->head); |
| if (mod & FSFATAL) { |
| /* If the reconnect failed, then just clear the chain */ |
| pwarn("Error reconnecting chain - clearing\n"); |
| mod &= ~FSFATAL; |
| next = RB_NEXT(FSCK_MSDOS_CACHE,0,fat); |
| clearchain(boot,fat,fat->head); |
| mod |= FSFATMOD; |
| fat = next; |
| continue; |
| } |
| if (ret == FSERROR && ask(1, "Clear")) { |
| next = RB_NEXT(FSCK_MSDOS_CACHE,0,fat); |
| clearchain(boot, fat, fat->head); |
| mod |= FSFATMOD; |
| fat = next; |
| continue; |
| } |
| fat = RB_NEXT(FSCK_MSDOS_CACHE,0,fat); |
| } |
| finishlf(); |
| fsck_debug("Verify Filesystem information\n"); |
| //verify the fs infomation |
| 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)) { |
| pwarn("Next free cluster in FSInfo block out of range\n"); |
| if (ask(1, "Fix")){ |
| boot->FSNext = firstfreecl; |
| ret = 1; |
| } |
| } |
| } |
| if (boot->FSNext > boot->NumClusters || boot->FSNext < CLUST_FIRST) { |
| pwarn("FSNext block (%d) not correct NumClusters (%d)\n", |
| boot->FSNext, boot->NumClusters); |
| boot->FSNext=CLUST_FIRST; // boot->FSNext can have -1 value. |
| } |
| if (ret) |
| mod |= writefsinfo(dosfs, boot); |
| } |
| |
| return mod; |
| } |