super.c

嵌入式系统设计与实验教材二源码linux内核移植与编译

      uid=xxx           set uid of files that don't have uid specified in eas\n\
      gid=xxx           set gid of files that don't have gid specified in eas\n\
      umask=xxx         set mode of files that don't have mode specified in eas\n\
      case=lower        lowercase all files\n\
      case=asis         do not lowercase files (default)\n\
      conv=binary       do not convert CR/LF -> LF (default)\n\
      conv=auto         convert only files with known text extensions\n\
      conv=text         convert all files\n\
      check=none        no fs checks - kernel may crash on corrupted filesystem\n\
      check=normal      do some checks - it should not crash (default)\n\
      check=strict      do extra time-consuming checks, used for debugging\n\
      errors=continue   continue on errors\n\
      errors=remount-ro remount read-only if errors found (default)\n\
      errors=panic      panic on errors\n\
      chkdsk=no         do not mark fs for chkdsking even if there were errors\n\
      chkdsk=errors     mark fs dirty if errors found (default)\n\
      chkdsk=always     always mark fs dirty - used for debugging\n\
      eas=no            ignore extended attributes\n\
      eas=ro            read but do not write extended attributes\n\
      eas=rw            r/w eas => enables chmod, chown, mknod, ln -s (default)\n\
      timeshift=nnn	add nnn seconds to file times\n\
\n");
}

int hpfs_remount_fs(struct super_block *s, int *flags, char *data)
{
	uid_t uid;
	gid_t gid;
	umode_t umask;
	int lowercase, conv, eas, chk, errs, chkdsk, timeshift;
	int o;
	
	*flags |= MS_NOATIME;
	
	uid = s->s_hpfs_uid; gid = s->s_hpfs_gid;
	umask = 0777 & ~s->s_hpfs_mode;
	lowercase = s->s_hpfs_lowercase; conv = s->s_hpfs_conv;
	eas = s->s_hpfs_eas; chk = s->s_hpfs_chk; chkdsk = s->s_hpfs_chkdsk;
	errs = s->s_hpfs_err; timeshift = s->s_hpfs_timeshift;

	if (!(o = parse_opts(data, &uid, &gid, &umask, &lowercase, &conv,
	    &eas, &chk, &errs, &chkdsk, &timeshift))) {
		printk("HPFS: bad mount options.\n");
	    	return 1;
	}
	if (o == 2) {
		hpfs_help();
		return 1;
	}
	if (timeshift != s->s_hpfs_timeshift) {
		printk("HPFS: timeshift can't be changed using remount.\n");
		return 1;
	}

	unmark_dirty(s);

	s->s_hpfs_uid = uid; s->s_hpfs_gid = gid;
	s->s_hpfs_mode = 0777 & ~umask;
	s->s_hpfs_lowercase = lowercase; s->s_hpfs_conv = conv;
	s->s_hpfs_eas = eas; s->s_hpfs_chk = chk; s->s_hpfs_chkdsk = chkdsk;
	s->s_hpfs_err = errs; s->s_hpfs_timeshift = timeshift;

	if (!(*flags & MS_RDONLY)) mark_dirty(s);

	return 0;
}

struct super_block *hpfs_read_super(struct super_block *s, void *options,
				    int silent)
{
	kdev_t dev;
	struct buffer_head *bh0, *bh1, *bh2;
	struct hpfs_boot_block *bootblock;
	struct hpfs_super_block *superblock;
	struct hpfs_spare_block *spareblock;

	uid_t uid;
	gid_t gid;
	umode_t umask;
	int lowercase, conv, eas, chk, errs, chkdsk, timeshift;

	dnode_secno root_dno;
	struct hpfs_dirent *de = NULL;
	struct quad_buffer_head qbh;

	int o;

	s->s_hpfs_bmp_dir = NULL;
	s->s_hpfs_cp_table = NULL;

	s->s_hpfs_creation_de_lock = s->s_hpfs_rd_inode = 0;
	init_waitqueue_head(&s->s_hpfs_creation_de);
	init_waitqueue_head(&s->s_hpfs_iget_q);

	uid = current->uid;
	gid = current->gid;
	umask = current->fs->umask;
	lowercase = 0;
	conv = CONV_BINARY;
	eas = 2;
	chk = 1;
	errs = 1;
	chkdsk = 1;
	timeshift = 0;

	if (!(o = parse_opts(options, &uid, &gid, &umask, &lowercase, &conv,
	    &eas, &chk, &errs, &chkdsk, &timeshift))) {
		printk("HPFS: bad mount options.\n");
		goto bail0;
	}
	if (o==2) {
		hpfs_help();
		goto bail0;
	}

	/*s->s_hpfs_mounting = 1;*/
	dev = s->s_dev;
	set_blocksize(dev, 512);
	s->s_hpfs_fs_size = -1;
	if (!(bootblock = hpfs_map_sector(s, 0, &bh0, 0))) goto bail1;
	if (!(superblock = hpfs_map_sector(s, 16, &bh1, 1))) goto bail2;
	if (!(spareblock = hpfs_map_sector(s, 17, &bh2, 0))) goto bail3;

	/* Check magics */
	if (/*bootblock->magic != BB_MAGIC
	    ||*/ superblock->magic != SB_MAGIC
	    || spareblock->magic != SP_MAGIC) {
		if (!silent) printk("HPFS: Bad magic ... probably not HPFS\n");
		goto bail4;
	}

	/* Check version */
	if (!(s->s_flags & MS_RDONLY) &&
	      superblock->funcversion != 2 && superblock->funcversion != 3) {
		printk("HPFS: Bad version %d,%d. Mount readonly to go around\n",
			(int)superblock->version, (int)superblock->funcversion);
		printk("HPFS: please try recent version of HPFS driver at http://artax.karlin.mff.cuni.cz/~mikulas/vyplody/hpfs/index-e.cgi and if it still can't understand this format, contact author - [e-mail]\n");
		goto bail4;
	}

	s->s_flags |= MS_NOATIME;

	/* Fill superblock stuff */
	s->s_magic = HPFS_SUPER_MAGIC;
	s->s_blocksize = 512;
	s->s_blocksize_bits = 9;
	s->s_op = &hpfs_sops;

	s->s_hpfs_root = superblock->root;
	s->s_hpfs_fs_size = superblock->n_sectors;
	s->s_hpfs_bitmaps = superblock->bitmaps;
	s->s_hpfs_dirband_start = superblock->dir_band_start;
	s->s_hpfs_dirband_size = superblock->n_dir_band;
	s->s_hpfs_dmap = superblock->dir_band_bitmap;
	s->s_hpfs_uid = uid;
	s->s_hpfs_gid = gid;
	s->s_hpfs_mode = 0777 & ~umask;
	s->s_hpfs_n_free = -1;
	s->s_hpfs_n_free_dnodes = -1;
	s->s_hpfs_lowercase = lowercase;
	s->s_hpfs_conv = conv;
	s->s_hpfs_eas = eas;
	s->s_hpfs_chk = chk;
	s->s_hpfs_chkdsk = chkdsk;
	s->s_hpfs_err = errs;
	s->s_hpfs_timeshift = timeshift;
	s->s_hpfs_was_error = 0;
	s->s_hpfs_cp_table = NULL;
	s->s_hpfs_c_bitmap = -1;
	
	/* Load bitmap directory */
	if (!(s->s_hpfs_bmp_dir = hpfs_load_bitmap_directory(s, superblock->bitmaps)))
		goto bail4;
	
	/* Check for general fs errors*/
	if (spareblock->dirty && !spareblock->old_wrote) {
		if (errs == 2) {
			printk("HPFS: Improperly stopped, not mounted\n");
			goto bail4;
		}
		hpfs_error(s, "improperly stopped");
	}

	if (!(s->s_flags & MS_RDONLY)) {
		spareblock->dirty = 1;
		spareblock->old_wrote = 0;
		mark_buffer_dirty(bh2);
	}

	if (spareblock->hotfixes_used || spareblock->n_spares_used) {
		if (errs >= 2) {
			printk("HPFS: Hotfixes not supported here, try chkdsk\n");
			mark_dirty(s);
			goto bail4;
		}
		hpfs_error(s, "hotfixes not supported here, try chkdsk");
		if (errs == 0) printk("HPFS: Proceeding, but your filesystem will be probably corrupted by this driver...\n");
		else printk("HPFS: This driver may read bad files or crash when operating on disk with hotfixes.\n");
	}
	if (spareblock->n_dnode_spares != spareblock->n_dnode_spares_free) {
		if (errs >= 2) {
			printk("HPFS: Spare dnodes used, try chkdsk\n");
			mark_dirty(s);
			goto bail4;
		}
		hpfs_error(s, "warning: spare dnodes used, try chkdsk");
		if (errs == 0) printk("HPFS: Proceeding, but your filesystem could be corrupted if you delete files or directories\n");
	}
	if (chk) {
		unsigned a;
		if (superblock->dir_band_end - superblock->dir_band_start + 1 != superblock->n_dir_band ||
		    superblock->dir_band_end < superblock->dir_band_start || superblock->n_dir_band > 0x4000) {
			hpfs_error(s, "dir band size mismatch: dir_band_start==%08x, dir_band_end==%08x, n_dir_band==%08x",
				superblock->dir_band_start, superblock->dir_band_end, superblock->n_dir_band);
			goto bail4;
		}
		a = s->s_hpfs_dirband_size;
		s->s_hpfs_dirband_size = 0;
		if (hpfs_chk_sectors(s, superblock->dir_band_start, superblock->n_dir_band, "dir_band") ||
		    hpfs_chk_sectors(s, superblock->dir_band_bitmap, 4, "dir_band_bitmap") ||
		    hpfs_chk_sectors(s, superblock->bitmaps, 4, "bitmaps")) {
			mark_dirty(s);
			goto bail4;
		}
		s->s_hpfs_dirband_size = a;
	} else printk("HPFS: You really don't want any checks? You are crazy...\n");

	/* Load code page table */
	if (spareblock->n_code_pages)
		if (!(s->s_hpfs_cp_table = hpfs_load_code_page(s, spareblock->code_page_dir)))
			printk("HPFS: Warning: code page support is disabled\n");

	brelse(bh2);
	brelse(bh1);
	brelse(bh0);

	hpfs_lock_iget(s, 1);
	s->s_root = d_alloc_root(iget(s, s->s_hpfs_root));
	hpfs_unlock_iget(s);
	if (!s->s_root || !s->s_root->d_inode) {
		printk("HPFS: iget failed. Why???\n");
		goto bail0;
	}
	hpfs_set_dentry_operations(s->s_root);

	/*
	 * find the root directory's . pointer & finish filling in the inode
	 */

	root_dno = hpfs_fnode_dno(s, s->s_hpfs_root);
	if (root_dno)
		de = map_dirent(s->s_root->d_inode, root_dno, "\001\001", 2, NULL, &qbh);
	if (!root_dno || !de) hpfs_error(s, "unable to find root dir");
	else {
		s->s_root->d_inode->i_atime = local_to_gmt(s, de->read_date);
		s->s_root->d_inode->i_mtime = local_to_gmt(s, de->write_date);
		s->s_root->d_inode->i_ctime = local_to_gmt(s, de->creation_date);
		s->s_root->d_inode->i_hpfs_ea_size = de->ea_size;
		s->s_root->d_inode->i_hpfs_parent_dir = s->s_root->d_inode->i_ino;
		if (s->s_root->d_inode->i_size == -1) s->s_root->d_inode->i_size = 2048;
		if (s->s_root->d_inode->i_blocks == -1) s->s_root->d_inode->i_blocks = 5;
	}
	if (de) hpfs_brelse4(&qbh);

	return s;

bail4:	brelse(bh2);
bail3:	brelse(bh1);
bail2:	brelse(bh0);
bail1:
bail0:
	if (s->s_hpfs_bmp_dir) kfree(s->s_hpfs_bmp_dir);
	if (s->s_hpfs_cp_table) kfree(s->s_hpfs_cp_table);
	return NULL;
}

DECLARE_FSTYPE_DEV(hpfs_fs_type, "hpfs", hpfs_read_super);

static int __init init_hpfs_fs(void)
{
	return register_filesystem(&hpfs_fs_type);
}

static void __exit exit_hpfs_fs(void)
{
	unregister_filesystem(&hpfs_fs_type);
}

EXPORT_NO_SYMBOLS;

module_init(init_hpfs_fs)
module_exit(exit_hpfs_fs)