check.c

来自「linux dosfs 工具,可以移植到嵌入式系统下检查存储状态下的磁盘状况,修」· C语言 代码 · 共 850 行 · 第 1/2 页

    if (FSTART(file,fs) >= fs->clusters+2) {
	printf("%s\n  Start cluster beyond limit (%lu > %lu). Truncating file.\n",
	  path_name(file),FSTART(file,fs),fs->clusters+1);
	if (!file->offset)
	    die( "Bad FAT32 root directory! (bad start cluster)\n" );
	MODIFY_START(file,0,fs);
    }
    clusters = prev = 0;
    for (curr = FSTART(file,fs) ? FSTART(file,fs) :
      -1; curr != -1; curr = next_cluster(fs,curr)) {
	if (!fs->fat[curr].value || bad_cluster(fs,curr)) {
	    printf("%s\n  Contains a %s cluster (%lu). Assuming EOF.\n",
	      path_name(file),fs->fat[curr].value ? "bad" : "free",curr);
	    if (prev) set_fat(fs,prev,-1);
	    else if (!file->offset)
		die( "FAT32 root dir starts with a bad cluster!" );
	    else MODIFY_START(file,0,fs);
	    break;
	}
	if (!(file->dir_ent.attr & ATTR_DIR) && CF_LE_L(file->dir_ent.size) <=
	  clusters*fs->cluster_size) {
	    printf("%s\n  File size is %u bytes, cluster chain length is > %lu "
	      "bytes.\n  Truncating file to %u bytes.\n",path_name(file),
	      CF_LE_L(file->dir_ent.size),clusters*fs->cluster_size,
	      CF_LE_L(file->dir_ent.size));
	    truncate_file(fs,file,clusters);
	    break;
	}
	if ((owner = get_owner(fs,curr))) {
	    int do_trunc = 0;
	    printf("%s  and\n",path_name(owner));
	    printf("%s\n  share clusters.\n",path_name(file));
	    clusters2 = 0;
	    for (walk = FSTART(owner,fs); walk > 0 && walk != -1; walk =
	      next_cluster(fs,walk))
		if (walk == curr) break;
		else clusters2++;
	    restart = file->dir_ent.attr & ATTR_DIR;
	    if (!owner->offset) {
		printf( "  Truncating second to %lu bytes because first "
			"is FAT32 root dir.\n", clusters2*fs->cluster_size );
		do_trunc = 2;
	    }
	    else if (!file->offset) {
		printf( "  Truncating first to %lu bytes because second "
			"is FAT32 root dir.\n", clusters*fs->cluster_size );
		do_trunc = 1;
	    }
	    else if (interactive)
		printf("1) Truncate first to %lu bytes%s\n"
		  "2) Truncate second to %lu bytes\n",clusters*fs->cluster_size,
		  restart ? " and restart" : "",clusters2*fs->cluster_size);
	    else printf("  Truncating second to %lu bytes.\n",clusters2*
		  fs->cluster_size);
	    if (do_trunc != 2 &&
		(do_trunc == 1 ||
		 (interactive && get_key("12","?") == '1'))) {
		prev = 0;
		clusters = 0;
		for (this = FSTART(owner,fs); this > 0 && this != -1; this =
		  next_cluster(fs,this)) {
		    if (this == curr) {
			if (prev) set_fat(fs,prev,-1);
			else MODIFY_START(owner,0,fs);
			MODIFY(owner,size,CT_LE_L(clusters*fs->cluster_size));
			if (restart) return 1;
			while (this > 0 && this != -1) {
			    set_owner(fs,this,NULL);
			    this = next_cluster(fs,this);
			}
			break;
		    }
		    clusters++;
		    prev = this;
		}
		if (this != curr)
		    die("Internal error: didn't find cluster %d in chain"
		      " starting at %d",curr,FSTART(owner,fs));
	    }
	    else {
		if (prev) set_fat(fs,prev,-1);
		else MODIFY_START(file,0,fs);
		break;
	    }
	}
	set_owner(fs,curr,file);
	clusters++;
	prev = curr;
    }
    if (!(file->dir_ent.attr & ATTR_DIR) && CF_LE_L(file->dir_ent.size) >
      clusters*fs->cluster_size) {
	printf("%s\n  File size is %u bytes, cluster chain length is %lu bytes."
	  "\n  Truncating file to %lu bytes.\n",path_name(file),CF_LE_L(file->
	  dir_ent.size),clusters*fs->cluster_size,clusters*fs->cluster_size);
	MODIFY(file,size,CT_LE_L(clusters*fs->cluster_size));
    }
    return 0;
}


static int check_files(DOS_FS *fs,DOS_FILE *start)
{
    while (start) {
	if (check_file(fs,start)) return 1;
	start = start->next;
    }
    return 0;
}


static int check_dir(DOS_FS *fs,DOS_FILE **root,int dots)
{
    DOS_FILE *parent,**walk,**scan;
    int dot,dotdot,skip,redo;
    int good,bad;

    if (!*root) return 0;
    parent = (*root)->parent;
    good = bad = 0;
    for (walk = root; *walk; walk = &(*walk)->next)
	if (bad_name((*walk)->dir_ent.name)) bad++;
	else good++;
    if (*root && parent && good+bad > 4 && bad > good/2) {
	printf("%s\n  Has a large number of bad entries. (%d/%d)\n",
	  path_name(parent),bad,good+bad);
	if (!dots) printf( "  Not dropping root directory.\n" );
	else if (!interactive) printf("  Not dropping it in auto-mode.\n");
	else if (get_key("yn","Drop directory ? (y/n)") == 'y') {
	    truncate_file(fs,parent,0);
	    MODIFY(parent,name[0],DELETED_FLAG);
	    /* buglet: deleted directory stays in the list. */
	    return 1;
	}
    }
    dot = dotdot = redo = 0;
    walk = root;
    while (*walk) {
	if (!strncmp((*walk)->dir_ent.name,MSDOS_DOT,MSDOS_NAME) ||
	  !strncmp((*walk)->dir_ent.name,MSDOS_DOTDOT,MSDOS_NAME)) {
	    if (handle_dot(fs,*walk,dots)) {
		*walk = (*walk)->next;
		continue;
	    }
	    if (!strncmp((*walk)->dir_ent.name,MSDOS_DOT,MSDOS_NAME)) dot++;
	    else dotdot++;
	}
	if (!((*walk)->dir_ent.attr & ATTR_VOLUME) &&
	    bad_name((*walk)->dir_ent.name)) {
	    printf("%s\n  Bad file name.\n",path_name(*walk));
	    if (interactive)
		printf("1) Drop file\n2) Rename file\n3) Auto-rename\n"
		  "4) Keep it\n");
	    else printf("  Auto-renaming it.\n");
	    switch (interactive ? get_key("1234","?") : '3') {
		case '1':
		    drop_file(fs,*walk);
		    walk = &(*walk)->next;
		    continue;
		case '2':
		    rename_file(*walk);
		    redo = 1;
		    break;
		case '3':
		    auto_rename(*walk);
		    printf("  Renamed to %s\n",file_name((*walk)->dir_ent.
		      name));
		    break;
		case '4':
		    break;
	    }
	}
	/* don't check for duplicates of the volume label */
	if (!((*walk)->dir_ent.attr & ATTR_VOLUME)) {
	    scan = &(*walk)->next;
	    skip = 0;
	    while (*scan && !skip) {
		if (!((*scan)->dir_ent.attr & ATTR_VOLUME) &&
		    !strncmp((*walk)->dir_ent.name,(*scan)->dir_ent.name,MSDOS_NAME)) {
		    printf("%s\n  Duplicate directory entry.\n  First  %s\n",
			   path_name(*walk),file_stat(*walk));
		    printf("  Second %s\n",file_stat(*scan));
		    if (interactive)
			printf("1) Drop first\n2) Drop second\n3) Rename first\n"
			       "4) Rename second\n5) Auto-rename first\n"
			       "6) Auto-rename second\n");
		    else printf("  Auto-renaming second.\n");
		    switch (interactive ? get_key("123456","?") : '6') {
		      case '1':
			drop_file(fs,*walk);
			*walk = (*walk)->next;
			skip = 1;
			break;
		      case '2':
			drop_file(fs,*scan);
			*scan = (*scan)->next;
			continue;
		      case '3':
			rename_file(*walk);
			printf("  Renamed to %s\n",path_name(*walk));
			redo = 1;
			break;
		      case '4':
			rename_file(*scan);
			printf("  Renamed to %s\n",path_name(*walk));
			redo = 1;
			break;
		      case '5':
			auto_rename(*walk);
			printf("  Renamed to %s\n",file_name((*walk)->dir_ent.
			  name));
			break;
		      case '6':
			auto_rename(*scan);
			printf("  Renamed to %s\n",file_name((*scan)->dir_ent.
			  name));
			break;
		    }
		}
		scan = &(*scan)->next;
	    }
	    if (skip) continue;
	}
	if (!redo) walk = &(*walk)->next;
	else {
	    walk = root;
	    dot = dotdot = redo = 0;
	}
    }
    if (dots && !dot)
	printf("%s\n  \".\" is missing. Can't fix this yet.\n",
	  path_name(parent));
    if (dots && !dotdot)
	printf("%s\n  \"..\" is missing. Can't fix this yet.\n",
	  path_name(parent));
    return 0;
}


static void test_file(DOS_FS *fs,DOS_FILE *file,int read_test)
{
    DOS_FILE *owner;
    unsigned long walk,prev,clusters,next_clu;

    prev = clusters = 0;
    for (walk = FSTART(file,fs); walk > 0 && walk < fs->clusters+2;
      walk = next_clu) {
	next_clu = next_cluster(fs,walk);
	if ((owner = get_owner(fs,walk))) {
	    if (owner == file) {
		printf("%s\n  Circular cluster chain. Truncating to %lu "
		  "cluster%s.\n",path_name(file),clusters,clusters == 1 ? "" :
		  "s");
		if (prev) set_fat(fs,prev,-1);
		else if (!file->offset)
		    die( "Bad FAT32 root directory! (bad start cluster)\n" );
		else MODIFY_START(file,0,fs);
	    }
	    break;
	}
	if (bad_cluster(fs,walk)) break;
	if (read_test) {
	    if (fs_test(cluster_start(fs,walk),fs->cluster_size)) {
		prev = walk;
		clusters++;
	    }
	    else {
		printf("%s\n  Cluster %lu (%lu) is unreadable. Skipping it.\n",
		  path_name(file),clusters,walk);
		if (prev) set_fat(fs,prev,next_cluster(fs,walk));
		else MODIFY_START(file,next_cluster(fs,walk),fs);
		set_fat(fs,walk,-2);
	    }
	}
	set_owner(fs,walk,file);
    }
    for (walk = FSTART(file,fs); walk > 0 && walk < fs->clusters+2;
      walk = next_cluster(fs,walk))
	if (bad_cluster(fs,walk)) break;
	else if (get_owner(fs,walk) == file) set_owner(fs,walk,NULL);
	    else break;
}


static void undelete(DOS_FS *fs,DOS_FILE *file)
{
    unsigned long clusters,left,prev,walk;

    clusters = left = (CF_LE_L(file->dir_ent.size)+fs->cluster_size-1)/
      fs->cluster_size;
    prev = 0;
    for (walk = FSTART(file,fs); left && walk >= 2 && walk <
       fs->clusters+2 && !fs->fat[walk].value; walk++) {
	left--;
	if (prev) set_fat(fs,prev,walk);
	prev = walk;
    }
    if (prev) set_fat(fs,prev,-1);
    else MODIFY_START(file,0,fs);
    if (left)
	printf("Warning: Did only undelete %lu of %lu cluster%s.\n",clusters-left,
	  clusters,clusters == 1 ? "" : "s");
   
}


static void new_dir( void )
{
    lfn_reset();
}


static void add_file(DOS_FS *fs,DOS_FILE ***chain,DOS_FILE *parent,
					 loff_t offset,FDSC **cp)
{
    DOS_FILE *new;
    DIR_ENT de;
    FD_TYPE type;

    if (offset)
	fs_read(offset,sizeof(DIR_ENT),&de);
    else {
	memcpy(de.name,"           ",MSDOS_NAME);
	de.attr = ATTR_DIR;
	de.size = de.time = de.date = 0;
	de.start = CT_LE_W(fs->root_cluster & 0xffff);
	de.starthi = CT_LE_W((fs->root_cluster >> 16) & 0xffff);
    }
    if ((type = file_type(cp,de.name)) != fdt_none) {
	if (type == fdt_undelete && (de.attr & ATTR_DIR))
	    die("Can't undelete directories.");
	file_modify(cp,de.name);
	fs_write(offset,1,&de);
    }
    if (IS_FREE(de.name)) return;
    if (de.attr == VFAT_LN_ATTR) {
	lfn_add_slot(&de,offset);
	return;
    }
    new = qalloc(&mem_queue,sizeof(DOS_FILE));
    new->lfn = lfn_get(&de);
    new->offset = offset;
    memcpy(&new->dir_ent,&de,sizeof(de));
    new->next = new->first = NULL;
    new->parent = parent;
    if (type == fdt_undelete) undelete(fs,new);
    **chain = new;
    *chain = &new->next;
    if (list) {
	printf("Checking file %s",path_name(new));
	if (new->lfn)
	    printf(" (%s)", file_name(new->dir_ent.name) );
	printf("\n");
    }
    if (offset &&
	strncmp(de.name,MSDOS_DOT,MSDOS_NAME) != 0 &&
	strncmp(de.name,MSDOS_DOTDOT,MSDOS_NAME) != 0)
	++n_files;
    test_file(fs,new,test);
}


static int subdirs(DOS_FS *fs,DOS_FILE *parent,FDSC **cp);


static int scan_dir(DOS_FS *fs,DOS_FILE *this,FDSC **cp)
{
    DOS_FILE **chain;
    int i;
    unsigned long clu_num;

    chain = &this->first;
    i = 0;
    clu_num = FSTART(this,fs);
    new_dir();
    while (clu_num > 0 && clu_num != -1) {
	add_file(fs,&chain,this,cluster_start(fs,clu_num)+(i % fs->
	  cluster_size),cp);
	i += sizeof(DIR_ENT);
	if (!(i % fs->cluster_size))
	    if ((clu_num = next_cluster(fs,clu_num)) == 0 || clu_num == -1)
		break;
    }
    if (check_dir(fs,&this->first,this->offset)) return 0;
    if (check_files(fs,this->first)) return 1;
    return subdirs(fs,this,cp);
}


static int subdirs(DOS_FS *fs,DOS_FILE *parent,FDSC **cp)
{
    DOS_FILE *walk;

    for (walk = parent ? parent->first : root; walk; walk = walk->next)
	if (walk->dir_ent.attr & ATTR_DIR)
	    if (strncmp(walk->dir_ent.name,MSDOS_DOT,MSDOS_NAME) &&
	      strncmp(walk->dir_ent.name,MSDOS_DOTDOT,MSDOS_NAME))
		if (scan_dir(fs,walk,file_cd(cp,walk->dir_ent.name))) return 1;
    return 0;
}


int scan_root(DOS_FS *fs)
{
    DOS_FILE **chain;
    int i;

    root = NULL;
    chain = &root;
    new_dir();
    if (fs->root_cluster) {
	add_file(fs,&chain,NULL,0,&fp_root);
    }
    else {
	for (i = 0; i < fs->root_entries; i++)
	    add_file(fs,&chain,NULL,fs->root_start+i*sizeof(DIR_ENT),&fp_root);
    }
    (void) check_dir(fs,&root,0);
    if (check_files(fs,root)) return 1;
    return subdirs(fs,NULL,&fp_root);
}

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