dir.c 32.4 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
/*
 *  linux/fs/fat/dir.c
 *
 *  directory handling functions for fat-based filesystems
 *
 *  Written 1992,1993 by Werner Almesberger
 *
 *  Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
 *
 *  VFAT extensions by Gordon Chaffee <chaffee@plateau.cs.berkeley.edu>
 *  Merged with msdos fs by Henrik Storner <storner@osiris.ping.dk>
 *  Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV
 *  Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/msdos_fs.h>
#include <linux/dirent.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
23
#include <linux/compat.h>
L
Linus Torvalds 已提交
24 25 26 27 28 29 30 31 32 33
#include <asm/uaccess.h>

static inline loff_t fat_make_i_pos(struct super_block *sb,
				    struct buffer_head *bh,
				    struct msdos_dir_entry *de)
{
	return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
		| (de - (struct msdos_dir_entry *)bh->b_data);
}

34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
				     sector_t phys)
{
	struct super_block *sb = dir->i_sb;
	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	struct buffer_head *bh;
	int sec;

	/* This is not a first sector of cluster, or sec_per_clus == 1 */
	if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
		return;
	/* root dir of FAT12/FAT16 */
	if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
		return;

49 50
	bh = sb_find_get_block(sb, phys);
	if (bh == NULL || !buffer_uptodate(bh)) {
51 52 53 54 55 56
		for (sec = 0; sec < sbi->sec_per_clus; sec++)
			sb_breadahead(sb, phys + sec);
	}
	brelse(bh);
}

L
Linus Torvalds 已提交
57 58 59 60 61 62 63 64 65 66 67 68 69 70 71
/* Returns the inode number of the directory entry at offset pos. If bh is
   non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
   returned in bh.
   AV. Most often we do it item-by-item. Makes sense to optimize.
   AV. OK, there we go: if both bh and de are non-NULL we assume that we just
   AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
   AV. It's done in fat_get_entry() (inlined), here the slow case lives.
   AV. Additionally, when we return -1 (i.e. reached the end of directory)
   AV. we make bh NULL.
 */
static int fat__get_entry(struct inode *dir, loff_t *pos,
			  struct buffer_head **bh, struct msdos_dir_entry **de)
{
	struct super_block *sb = dir->i_sb;
	sector_t phys, iblock;
72 73
	unsigned long mapped_blocks;
	int err, offset;
L
Linus Torvalds 已提交
74 75 76 77 78 79 80

next:
	if (*bh)
		brelse(*bh);

	*bh = NULL;
	iblock = *pos >> sb->s_blocksize_bits;
81
	err = fat_bmap(dir, iblock, &phys, &mapped_blocks);
L
Linus Torvalds 已提交
82 83 84
	if (err || !phys)
		return -1;	/* beyond EOF or error */

85 86
	fat_dir_readahead(dir, iblock, phys);

L
Linus Torvalds 已提交
87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117
	*bh = sb_bread(sb, phys);
	if (*bh == NULL) {
		printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
		       (unsigned long long)phys);
		/* skip this block */
		*pos = (iblock + 1) << sb->s_blocksize_bits;
		goto next;
	}

	offset = *pos & (sb->s_blocksize - 1);
	*pos += sizeof(struct msdos_dir_entry);
	*de = (struct msdos_dir_entry *)((*bh)->b_data + offset);

	return 0;
}

static inline int fat_get_entry(struct inode *dir, loff_t *pos,
				struct buffer_head **bh,
				struct msdos_dir_entry **de)
{
	/* Fast stuff first */
	if (*bh && *de &&
	    (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
		*pos += sizeof(struct msdos_dir_entry);
		(*de)++;
		return 0;
	}
	return fat__get_entry(dir, pos, bh, de);
}

/*
A
Alexey Dobriyan 已提交
118
 * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
L
Linus Torvalds 已提交
119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225
 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
 * colon as an escape character since it is normally invalid on the vfat
 * filesystem. The following four characters are the hexadecimal digits
 * of Unicode value. This lets us do a full dump and restore of Unicode
 * filenames. We could get into some trouble with long Unicode names,
 * but ignore that right now.
 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
 */
static int uni16_to_x8(unsigned char *ascii, wchar_t *uni, int uni_xlate,
		       struct nls_table *nls)
{
	wchar_t *ip, ec;
	unsigned char *op, nc;
	int charlen;
	int k;

	ip = uni;
	op = ascii;

	while (*ip) {
		ec = *ip++;
		if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
			op += charlen;
		} else {
			if (uni_xlate == 1) {
				*op = ':';
				for (k = 4; k > 0; k--) {
					nc = ec & 0xF;
					op[k] = nc > 9	? nc + ('a' - 10)
							: nc + '0';
					ec >>= 4;
				}
				op += 5;
			} else {
				*op++ = '?';
			}
		}
		/* We have some slack there, so it's OK */
		if (op>ascii+256) {
			op = ascii + 256;
			break;
		}
	}
	*op = 0;
	return (op - ascii);
}

static inline int
fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
{
	int charlen;

	charlen = t->char2uni(c, clen, uni);
	if (charlen < 0) {
		*uni = 0x003f;	/* a question mark */
		charlen = 1;
	}
	return charlen;
}

static inline int
fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
{
	int charlen;
	wchar_t wc;

	charlen = t->char2uni(c, clen, &wc);
	if (charlen < 0) {
		*uni = 0x003f;	/* a question mark */
		charlen = 1;
	} else if (charlen <= 1) {
		unsigned char nc = t->charset2lower[*c];

		if (!nc)
			nc = *c;

		if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
			*uni = 0x003f;	/* a question mark */
			charlen = 1;
		}
	} else
		*uni = wc;

	return charlen;
}

static inline int
fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
		  wchar_t *uni_buf, unsigned short opt, int lower)
{
	int len = 0;

	if (opt & VFAT_SFN_DISPLAY_LOWER)
		len =  fat_short2lower_uni(nls, buf, buf_size, uni_buf);
	else if (opt & VFAT_SFN_DISPLAY_WIN95)
		len = fat_short2uni(nls, buf, buf_size, uni_buf);
	else if (opt & VFAT_SFN_DISPLAY_WINNT) {
		if (lower)
			len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
		else
			len = fat_short2uni(nls, buf, buf_size, uni_buf);
	} else
		len = fat_short2uni(nls, buf, buf_size, uni_buf);

	return len;
}

226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299
enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };

/**
 * fat_parse_long - Parse extended directory entry.
 *
 * This function returns zero on success, negative value on error, or one of
 * the following:
 *
 * %PARSE_INVALID - Directory entry is invalid.
 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
 * %PARSE_EOF - Directory has no more entries.
 */
static int fat_parse_long(struct inode *dir, loff_t *pos,
			  struct buffer_head **bh, struct msdos_dir_entry **de,
			  wchar_t **unicode, unsigned char *nr_slots)
{
	struct msdos_dir_slot *ds;
	unsigned char id, slot, slots, alias_checksum;

	if (!*unicode) {
		*unicode = (wchar_t *)__get_free_page(GFP_KERNEL);
		if (!*unicode) {
			brelse(*bh);
			return -ENOMEM;
		}
	}
parse_long:
	slots = 0;
	ds = (struct msdos_dir_slot *)*de;
	id = ds->id;
	if (!(id & 0x40))
		return PARSE_INVALID;
	slots = id & ~0x40;
	if (slots > 20 || !slots)	/* ceil(256 * 2 / 26) */
		return PARSE_INVALID;
	*nr_slots = slots;
	alias_checksum = ds->alias_checksum;

	slot = slots;
	while (1) {
		int offset;

		slot--;
		offset = slot * 13;
		fat16_towchar(*unicode + offset, ds->name0_4, 5);
		fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
		fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);

		if (ds->id & 0x40)
			(*unicode)[offset + 13] = 0;
		if (fat_get_entry(dir, pos, bh, de) < 0)
			return PARSE_EOF;
		if (slot == 0)
			break;
		ds = (struct msdos_dir_slot *)*de;
		if (ds->attr != ATTR_EXT)
			return PARSE_NOT_LONGNAME;
		if ((ds->id & ~0x40) != slot)
			goto parse_long;
		if (ds->alias_checksum != alias_checksum)
			goto parse_long;
	}
	if ((*de)->name[0] == DELETED_FLAG)
		return PARSE_INVALID;
	if ((*de)->attr == ATTR_EXT)
		goto parse_long;
	if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
		return PARSE_INVALID;
	if (fat_checksum((*de)->name) != alias_checksum)
		*nr_slots = 0;

	return 0;
}

L
Linus Torvalds 已提交
300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336
/*
 * Return values: negative -> error, 0 -> not found, positive -> found,
 * value is the total amount of slots, including the shortname entry.
 */
int fat_search_long(struct inode *inode, const unsigned char *name,
		    int name_len, struct fat_slot_info *sinfo)
{
	struct super_block *sb = inode->i_sb;
	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	struct buffer_head *bh = NULL;
	struct msdos_dir_entry *de;
	struct nls_table *nls_io = sbi->nls_io;
	struct nls_table *nls_disk = sbi->nls_disk;
	wchar_t bufuname[14];
	unsigned char xlate_len, nr_slots;
	wchar_t *unicode = NULL;
	unsigned char work[8], bufname[260];	/* 256 + 4 */
	int uni_xlate = sbi->options.unicode_xlate;
	int utf8 = sbi->options.utf8;
	int anycase = (sbi->options.name_check != 's');
	unsigned short opt_shortname = sbi->options.shortname;
	loff_t cpos = 0;
	int chl, i, j, last_u, err;

	err = -ENOENT;
	while(1) {
		if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
			goto EODir;
parse_record:
		nr_slots = 0;
		if (de->name[0] == DELETED_FLAG)
			continue;
		if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
			continue;
		if (de->attr != ATTR_EXT && IS_FREE(de->name))
			continue;
		if (de->attr == ATTR_EXT) {
337 338 339 340 341
			int status = fat_parse_long(inode, &cpos, &bh, &de,
						    &unicode, &nr_slots);
			if (status < 0)
				return status;
			else if (status == PARSE_INVALID)
L
Linus Torvalds 已提交
342
				continue;
343 344 345 346
			else if (status == PARSE_NOT_LONGNAME)
				goto parse_record;
			else if (status == PARSE_EOF)
				goto EODir;
L
Linus Torvalds 已提交
347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421
		}

		memcpy(work, de->name, sizeof(de->name));
		/* see namei.c, msdos_format_name */
		if (work[0] == 0x05)
			work[0] = 0xE5;
		for (i = 0, j = 0, last_u = 0; i < 8;) {
			if (!work[i]) break;
			chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
						&bufuname[j++], opt_shortname,
						de->lcase & CASE_LOWER_BASE);
			if (chl <= 1) {
				if (work[i] != ' ')
					last_u = j;
			} else {
				last_u = j;
			}
			i += chl;
		}
		j = last_u;
		fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
		for (i = 0; i < 3;) {
			if (!de->ext[i]) break;
			chl = fat_shortname2uni(nls_disk, &de->ext[i], 3 - i,
						&bufuname[j++], opt_shortname,
						de->lcase & CASE_LOWER_EXT);
			if (chl <= 1) {
				if (de->ext[i] != ' ')
					last_u = j;
			} else {
				last_u = j;
			}
			i += chl;
		}
		if (!last_u)
			continue;

		bufuname[last_u] = 0x0000;
		xlate_len = utf8
			?utf8_wcstombs(bufname, bufuname, sizeof(bufname))
			:uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
		if (xlate_len == name_len)
			if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
			    (anycase && !nls_strnicmp(nls_io, name, bufname,
								xlate_len)))
				goto Found;

		if (nr_slots) {
			xlate_len = utf8
				?utf8_wcstombs(bufname, unicode, sizeof(bufname))
				:uni16_to_x8(bufname, unicode, uni_xlate, nls_io);
			if (xlate_len != name_len)
				continue;
			if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
			    (anycase && !nls_strnicmp(nls_io, name, bufname,
								xlate_len)))
				goto Found;
		}
	}

Found:
	nr_slots++;	/* include the de */
	sinfo->slot_off = cpos - nr_slots * sizeof(*de);
	sinfo->nr_slots = nr_slots;
	sinfo->de = de;
	sinfo->bh = bh;
	sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
	err = 0;
EODir:
	if (unicode)
		free_page((unsigned long)unicode);

	return err;
}

422
EXPORT_SYMBOL_GPL(fat_search_long);
L
Linus Torvalds 已提交
423 424 425 426 427 428 429 430 431 432 433

struct fat_ioctl_filldir_callback {
	struct dirent __user *dirent;
	int result;
	/* for dir ioctl */
	const char *longname;
	int long_len;
	const char *shortname;
	int short_len;
};

434 435
static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
			 filldir_t filldir, int short_only, int both)
L
Linus Torvalds 已提交
436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485
{
	struct super_block *sb = inode->i_sb;
	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	struct buffer_head *bh;
	struct msdos_dir_entry *de;
	struct nls_table *nls_io = sbi->nls_io;
	struct nls_table *nls_disk = sbi->nls_disk;
	unsigned char long_slots;
	const char *fill_name;
	int fill_len;
	wchar_t bufuname[14];
	wchar_t *unicode = NULL;
	unsigned char c, work[8], bufname[56], *ptname = bufname;
	unsigned long lpos, dummy, *furrfu = &lpos;
	int uni_xlate = sbi->options.unicode_xlate;
	int isvfat = sbi->options.isvfat;
	int utf8 = sbi->options.utf8;
	int nocase = sbi->options.nocase;
	unsigned short opt_shortname = sbi->options.shortname;
	unsigned long inum;
	int chi, chl, i, i2, j, last, last_u, dotoffset = 0;
	loff_t cpos;
	int ret = 0;

	lock_kernel();

	cpos = filp->f_pos;
	/* Fake . and .. for the root directory. */
	if (inode->i_ino == MSDOS_ROOT_INO) {
		while (cpos < 2) {
			if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
				goto out;
			cpos++;
			filp->f_pos++;
		}
		if (cpos == 2) {
			dummy = 2;
			furrfu = &dummy;
			cpos = 0;
		}
	}
	if (cpos & (sizeof(struct msdos_dir_entry)-1)) {
		ret = -ENOENT;
		goto out;
	}

	bh = NULL;
GetNew:
	if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
		goto EODir;
486 487
parse_record:
	long_slots = 0;
L
Linus Torvalds 已提交
488 489 490 491 492 493 494 495 496 497 498 499 500 501
	/* Check for long filename entry */
	if (isvfat) {
		if (de->name[0] == DELETED_FLAG)
			goto RecEnd;
		if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
			goto RecEnd;
		if (de->attr != ATTR_EXT && IS_FREE(de->name))
			goto RecEnd;
	} else {
		if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
			goto RecEnd;
	}

	if (isvfat && de->attr == ATTR_EXT) {
502 503 504 505 506 507 508
		int status = fat_parse_long(inode, &cpos, &bh, &de,
					    &unicode, &long_slots);
		if (status < 0) {
			filp->f_pos = cpos;
			ret = status;
			goto out;
		} else if (status == PARSE_INVALID)
L
Linus Torvalds 已提交
509
			goto RecEnd;
510 511 512 513
		else if (status == PARSE_NOT_LONGNAME)
			goto parse_record;
		else if (status == PARSE_EOF)
			goto EODir;
L
Linus Torvalds 已提交
514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581
	}

	if (sbi->options.dotsOK) {
		ptname = bufname;
		dotoffset = 0;
		if (de->attr & ATTR_HIDDEN) {
			*ptname++ = '.';
			dotoffset = 1;
		}
	}

	memcpy(work, de->name, sizeof(de->name));
	/* see namei.c, msdos_format_name */
	if (work[0] == 0x05)
		work[0] = 0xE5;
	for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
		if (!(c = work[i])) break;
		chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
					&bufuname[j++], opt_shortname,
					de->lcase & CASE_LOWER_BASE);
		if (chl <= 1) {
			ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
			if (c != ' ') {
				last = i;
				last_u = j;
			}
		} else {
			last_u = j;
			for (chi = 0; chi < chl && i < 8; chi++) {
				ptname[i] = work[i];
				i++; last = i;
			}
		}
	}
	i = last;
	j = last_u;
	fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
	ptname[i++] = '.';
	for (i2 = 0; i2 < 3;) {
		if (!(c = de->ext[i2])) break;
		chl = fat_shortname2uni(nls_disk, &de->ext[i2], 3 - i2,
					&bufuname[j++], opt_shortname,
					de->lcase & CASE_LOWER_EXT);
		if (chl <= 1) {
			i2++;
			ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
			if (c != ' ') {
				last = i;
				last_u = j;
			}
		} else {
			last_u = j;
			for (chi = 0; chi < chl && i2 < 3; chi++) {
				ptname[i++] = de->ext[i2++];
				last = i;
			}
		}
	}
	if (!last)
		goto RecEnd;

	i = last + dotoffset;
	j = last_u;

	lpos = cpos - (long_slots+1)*sizeof(struct msdos_dir_entry);
	if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
		inum = inode->i_ino;
	else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
582
		inum = parent_ino(filp->f_path.dentry);
L
Linus Torvalds 已提交
583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635
	} else {
		loff_t i_pos = fat_make_i_pos(sb, bh, de);
		struct inode *tmp = fat_iget(sb, i_pos);
		if (tmp) {
			inum = tmp->i_ino;
			iput(tmp);
		} else
			inum = iunique(sb, MSDOS_ROOT_INO);
	}

	if (isvfat) {
		bufuname[j] = 0x0000;
		i = utf8 ? utf8_wcstombs(bufname, bufuname, sizeof(bufname))
			 : uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
	}

	fill_name = bufname;
	fill_len = i;
	if (!short_only && long_slots) {
		/* convert the unicode long name. 261 is maximum size
		 * of unicode buffer. (13 * slots + nul) */
		void *longname = unicode + 261;
		int buf_size = PAGE_SIZE - (261 * sizeof(unicode[0]));
		int long_len = utf8
			? utf8_wcstombs(longname, unicode, buf_size)
			: uni16_to_x8(longname, unicode, uni_xlate, nls_io);

		if (!both) {
			fill_name = longname;
			fill_len = long_len;
		} else {
			/* hack for fat_ioctl_filldir() */
			struct fat_ioctl_filldir_callback *p = dirent;

			p->longname = longname;
			p->long_len = long_len;
			p->shortname = bufname;
			p->short_len = i;
			fill_name = NULL;
			fill_len = 0;
		}
	}
	if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
		    (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
		goto FillFailed;

RecEnd:
	furrfu = &lpos;
	filp->f_pos = cpos;
	goto GetNew;
EODir:
	filp->f_pos = cpos;
FillFailed:
636
	brelse(bh);
L
Linus Torvalds 已提交
637 638 639 640 641 642 643 644 645
	if (unicode)
		free_page((unsigned long)unicode);
out:
	unlock_kernel();
	return ret;
}

static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
646
	struct inode *inode = filp->f_path.dentry->d_inode;
647
	return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
L
Linus Torvalds 已提交
648 649 650
}

static int fat_ioctl_filldir(void *__buf, const char *name, int name_len,
651
			     loff_t offset, u64 ino, unsigned int d_type)
L
Linus Torvalds 已提交
652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732
{
	struct fat_ioctl_filldir_callback *buf = __buf;
	struct dirent __user *d1 = buf->dirent;
	struct dirent __user *d2 = d1 + 1;

	if (buf->result)
		return -EINVAL;
	buf->result++;

	if (name != NULL) {
		/* dirent has only short name */
		if (name_len >= sizeof(d1->d_name))
			name_len = sizeof(d1->d_name) - 1;

		if (put_user(0, d2->d_name)			||
		    put_user(0, &d2->d_reclen)			||
		    copy_to_user(d1->d_name, name, name_len)	||
		    put_user(0, d1->d_name + name_len)		||
		    put_user(name_len, &d1->d_reclen))
			goto efault;
	} else {
		/* dirent has short and long name */
		const char *longname = buf->longname;
		int long_len = buf->long_len;
		const char *shortname = buf->shortname;
		int short_len = buf->short_len;

		if (long_len >= sizeof(d1->d_name))
			long_len = sizeof(d1->d_name) - 1;
		if (short_len >= sizeof(d1->d_name))
			short_len = sizeof(d1->d_name) - 1;

		if (copy_to_user(d2->d_name, longname, long_len)	||
		    put_user(0, d2->d_name + long_len)			||
		    put_user(long_len, &d2->d_reclen)			||
		    put_user(ino, &d2->d_ino)				||
		    put_user(offset, &d2->d_off)			||
		    copy_to_user(d1->d_name, shortname, short_len)	||
		    put_user(0, d1->d_name + short_len)			||
		    put_user(short_len, &d1->d_reclen))
			goto efault;
	}
	return 0;
efault:
	buf->result = -EFAULT;
	return -EFAULT;
}

static int fat_dir_ioctl(struct inode * inode, struct file * filp,
		  unsigned int cmd, unsigned long arg)
{
	struct fat_ioctl_filldir_callback buf;
	struct dirent __user *d1;
	int ret, short_only, both;

	switch (cmd) {
	case VFAT_IOCTL_READDIR_SHORT:
		short_only = 1;
		both = 0;
		break;
	case VFAT_IOCTL_READDIR_BOTH:
		short_only = 0;
		both = 1;
		break;
	default:
		return fat_generic_ioctl(inode, filp, cmd, arg);
	}

	d1 = (struct dirent __user *)arg;
	if (!access_ok(VERIFY_WRITE, d1, sizeof(struct dirent[2])))
		return -EFAULT;
	/*
	 * Yes, we don't need this put_user() absolutely. However old
	 * code didn't return the right value. So, app use this value,
	 * in order to check whether it is EOF.
	 */
	if (put_user(0, &d1->d_reclen))
		return -EFAULT;

	buf.dirent = d1;
	buf.result = 0;
733
	mutex_lock(&inode->i_mutex);
L
Linus Torvalds 已提交
734 735
	ret = -ENOENT;
	if (!IS_DEADDIR(inode)) {
736 737
		ret = __fat_readdir(inode, filp, &buf, fat_ioctl_filldir,
				    short_only, both);
L
Linus Torvalds 已提交
738
	}
739
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
740 741 742 743 744
	if (ret >= 0)
		ret = buf.result;
	return ret;
}

745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784
#ifdef CONFIG_COMPAT
#define	VFAT_IOCTL_READDIR_BOTH32	_IOR('r', 1, struct compat_dirent[2])
#define	VFAT_IOCTL_READDIR_SHORT32	_IOR('r', 2, struct compat_dirent[2])

static long fat_compat_put_dirent32(struct dirent *d,
				    struct compat_dirent __user *d32)
{
        if (!access_ok(VERIFY_WRITE, d32, sizeof(struct compat_dirent)))
                return -EFAULT;

        __put_user(d->d_ino, &d32->d_ino);
        __put_user(d->d_off, &d32->d_off);
        __put_user(d->d_reclen, &d32->d_reclen);
        if (__copy_to_user(d32->d_name, d->d_name, d->d_reclen))
		return -EFAULT;

        return 0;
}

static long fat_compat_dir_ioctl(struct file *file, unsigned cmd,
				 unsigned long arg)
{
	struct compat_dirent __user *p = compat_ptr(arg);
	int ret;
	mm_segment_t oldfs = get_fs();
	struct dirent d[2];

	switch (cmd) {
	case VFAT_IOCTL_READDIR_BOTH32:
		cmd = VFAT_IOCTL_READDIR_BOTH;
		break;
	case VFAT_IOCTL_READDIR_SHORT32:
		cmd = VFAT_IOCTL_READDIR_SHORT;
		break;
	default:
		return -ENOIOCTLCMD;
	}

	set_fs(KERNEL_DS);
	lock_kernel();
785
	ret = fat_dir_ioctl(file->f_path.dentry->d_inode, file,
786 787 788 789 790 791 792 793 794 795 796
			    cmd, (unsigned long) &d);
	unlock_kernel();
	set_fs(oldfs);
	if (ret >= 0) {
		ret |= fat_compat_put_dirent32(&d[0], p);
		ret |= fat_compat_put_dirent32(&d[1], p + 1);
	}
	return ret;
}
#endif /* CONFIG_COMPAT */

797
const struct file_operations fat_dir_operations = {
L
Linus Torvalds 已提交
798 799 800
	.read		= generic_read_dir,
	.readdir	= fat_readdir,
	.ioctl		= fat_dir_ioctl,
801 802 803
#ifdef CONFIG_COMPAT
	.compat_ioctl	= fat_compat_dir_ioctl,
#endif
L
Linus Torvalds 已提交
804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838
	.fsync		= file_fsync,
};

static int fat_get_short_entry(struct inode *dir, loff_t *pos,
			       struct buffer_head **bh,
			       struct msdos_dir_entry **de)
{
	while (fat_get_entry(dir, pos, bh, de) >= 0) {
		/* free entry or long name entry or volume label */
		if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
			return 0;
	}
	return -ENOENT;
}

/*
 * The ".." entry can not provide the "struct fat_slot_info" informations
 * for inode. So, this function provide the some informations only.
 */
int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
			 struct msdos_dir_entry **de, loff_t *i_pos)
{
	loff_t offset;

	offset = 0;
	*bh = NULL;
	while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
		if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
			*i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
			return 0;
		}
	}
	return -ENOENT;
}

839
EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
L
Linus Torvalds 已提交
840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861

/* See if directory is empty */
int fat_dir_empty(struct inode *dir)
{
	struct buffer_head *bh;
	struct msdos_dir_entry *de;
	loff_t cpos;
	int result = 0;

	bh = NULL;
	cpos = 0;
	while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
		if (strncmp(de->name, MSDOS_DOT   , MSDOS_NAME) &&
		    strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
			result = -ENOTEMPTY;
			break;
		}
	}
	brelse(bh);
	return result;
}

862
EXPORT_SYMBOL_GPL(fat_dir_empty);
L
Linus Torvalds 已提交
863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907

/*
 * fat_subdirs counts the number of sub-directories of dir. It can be run
 * on directories being created.
 */
int fat_subdirs(struct inode *dir)
{
	struct buffer_head *bh;
	struct msdos_dir_entry *de;
	loff_t cpos;
	int count = 0;

	bh = NULL;
	cpos = 0;
	while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
		if (de->attr & ATTR_DIR)
			count++;
	}
	brelse(bh);
	return count;
}

/*
 * Scans a directory for a given file (name points to its formatted name).
 * Returns an error code or zero.
 */
int fat_scan(struct inode *dir, const unsigned char *name,
	     struct fat_slot_info *sinfo)
{
	struct super_block *sb = dir->i_sb;

	sinfo->slot_off = 0;
	sinfo->bh = NULL;
	while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
				   &sinfo->de) >= 0) {
		if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
			sinfo->slot_off -= sizeof(*sinfo->de);
			sinfo->nr_slots = 1;
			sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
			return 0;
		}
	}
	return -ENOENT;
}

908
EXPORT_SYMBOL_GPL(fat_scan);
L
Linus Torvalds 已提交
909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994

static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
{
	struct super_block *sb = dir->i_sb;
	struct buffer_head *bh;
	struct msdos_dir_entry *de, *endp;
	int err = 0, orig_slots;

	while (nr_slots) {
		bh = NULL;
		if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
			err = -EIO;
			break;
		}

		orig_slots = nr_slots;
		endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
		while (nr_slots && de < endp) {
			de->name[0] = DELETED_FLAG;
			de++;
			nr_slots--;
		}
		mark_buffer_dirty(bh);
		if (IS_DIRSYNC(dir))
			err = sync_dirty_buffer(bh);
		brelse(bh);
		if (err)
			break;

		/* pos is *next* de's position, so this does `- sizeof(de)' */
		pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
	}

	return err;
}

int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
{
	struct msdos_dir_entry *de;
	struct buffer_head *bh;
	int err = 0, nr_slots;

	/*
	 * First stage: Remove the shortname. By this, the directory
	 * entry is removed.
	 */
	nr_slots = sinfo->nr_slots;
	de = sinfo->de;
	sinfo->de = NULL;
	bh = sinfo->bh;
	sinfo->bh = NULL;
	while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
		de->name[0] = DELETED_FLAG;
		de--;
		nr_slots--;
	}
	mark_buffer_dirty(bh);
	if (IS_DIRSYNC(dir))
		err = sync_dirty_buffer(bh);
	brelse(bh);
	if (err)
		return err;
	dir->i_version++;

	if (nr_slots) {
		/*
		 * Second stage: remove the remaining longname slots.
		 * (This directory entry is already removed, and so return
		 * the success)
		 */
		err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
		if (err) {
			printk(KERN_WARNING
			       "FAT: Couldn't remove the long name slots\n");
		}
	}

	dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
	if (IS_DIRSYNC(dir))
		(void)fat_sync_inode(dir);
	else
		mark_inode_dirty(dir);

	return 0;
}

995
EXPORT_SYMBOL_GPL(fat_remove_entries);
L
Linus Torvalds 已提交
996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106

static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
			      struct buffer_head **bhs, int nr_bhs)
{
	struct super_block *sb = dir->i_sb;
	sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
	int err, i, n;

	/* Zeroing the unused blocks on this cluster */
	blknr += nr_used;
	n = nr_used;
	while (blknr < last_blknr) {
		bhs[n] = sb_getblk(sb, blknr);
		if (!bhs[n]) {
			err = -ENOMEM;
			goto error;
		}
		memset(bhs[n]->b_data, 0, sb->s_blocksize);
		set_buffer_uptodate(bhs[n]);
		mark_buffer_dirty(bhs[n]);

		n++;
		blknr++;
		if (n == nr_bhs) {
			if (IS_DIRSYNC(dir)) {
				err = fat_sync_bhs(bhs, n);
				if (err)
					goto error;
			}
			for (i = 0; i < n; i++)
				brelse(bhs[i]);
			n = 0;
		}
	}
	if (IS_DIRSYNC(dir)) {
		err = fat_sync_bhs(bhs, n);
		if (err)
			goto error;
	}
	for (i = 0; i < n; i++)
		brelse(bhs[i]);

	return 0;

error:
	for (i = 0; i < n; i++)
		bforget(bhs[i]);
	return err;
}

int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
{
	struct super_block *sb = dir->i_sb;
	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	struct buffer_head *bhs[MAX_BUF_PER_PAGE];
	struct msdos_dir_entry *de;
	sector_t blknr;
	__le16 date, time;
	int err, cluster;

	err = fat_alloc_clusters(dir, &cluster, 1);
	if (err)
		goto error;

	blknr = fat_clus_to_blknr(sbi, cluster);
	bhs[0] = sb_getblk(sb, blknr);
	if (!bhs[0]) {
		err = -ENOMEM;
		goto error_free;
	}

	fat_date_unix2dos(ts->tv_sec, &time, &date);

	de = (struct msdos_dir_entry *)bhs[0]->b_data;
	/* filling the new directory slots ("." and ".." entries) */
	memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
	memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
	de->attr = de[1].attr = ATTR_DIR;
	de[0].lcase = de[1].lcase = 0;
	de[0].time = de[1].time = time;
	de[0].date = de[1].date = date;
	de[0].ctime_cs = de[1].ctime_cs = 0;
	if (sbi->options.isvfat) {
		/* extra timestamps */
		de[0].ctime = de[1].ctime = time;
		de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
	} else {
		de[0].ctime = de[1].ctime = 0;
		de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
	}
	de[0].start = cpu_to_le16(cluster);
	de[0].starthi = cpu_to_le16(cluster >> 16);
	de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
	de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
	de[0].size = de[1].size = 0;
	memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
	set_buffer_uptodate(bhs[0]);
	mark_buffer_dirty(bhs[0]);

	err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
	if (err)
		goto error_free;

	return cluster;

error_free:
	fat_free_clusters(dir, cluster);
error:
	return err;
}

1107
EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
L
Linus Torvalds 已提交
1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322

static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
			       int *nr_cluster, struct msdos_dir_entry **de,
			       struct buffer_head **bh, loff_t *i_pos)
{
	struct super_block *sb = dir->i_sb;
	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	struct buffer_head *bhs[MAX_BUF_PER_PAGE];
	sector_t blknr, start_blknr, last_blknr;
	unsigned long size, copy;
	int err, i, n, offset, cluster[2];

	/*
	 * The minimum cluster size is 512bytes, and maximum entry
	 * size is 32*slots (672bytes).  So, iff the cluster size is
	 * 512bytes, we may need two clusters.
	 */
	size = nr_slots * sizeof(struct msdos_dir_entry);
	*nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
	BUG_ON(*nr_cluster > 2);

	err = fat_alloc_clusters(dir, cluster, *nr_cluster);
	if (err)
		goto error;

	/*
	 * First stage: Fill the directory entry.  NOTE: This cluster
	 * is not referenced from any inode yet, so updates order is
	 * not important.
	 */
	i = n = copy = 0;
	do {
		start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
		last_blknr = start_blknr + sbi->sec_per_clus;
		while (blknr < last_blknr) {
			bhs[n] = sb_getblk(sb, blknr);
			if (!bhs[n]) {
				err = -ENOMEM;
				goto error_nomem;
			}

			/* fill the directory entry */
			copy = min(size, sb->s_blocksize);
			memcpy(bhs[n]->b_data, slots, copy);
			slots += copy;
			size -= copy;
			set_buffer_uptodate(bhs[n]);
			mark_buffer_dirty(bhs[n]);
			if (!size)
				break;
			n++;
			blknr++;
		}
	} while (++i < *nr_cluster);

	memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
	offset = copy - sizeof(struct msdos_dir_entry);
	get_bh(bhs[n]);
	*bh = bhs[n];
	*de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
	*i_pos = fat_make_i_pos(sb, *bh, *de);

	/* Second stage: clear the rest of cluster, and write outs */
	err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
	if (err)
		goto error_free;

	return cluster[0];

error_free:
	brelse(*bh);
	*bh = NULL;
	n = 0;
error_nomem:
	for (i = 0; i < n; i++)
		bforget(bhs[i]);
	fat_free_clusters(dir, cluster[0]);
error:
	return err;
}

int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
		    struct fat_slot_info *sinfo)
{
	struct super_block *sb = dir->i_sb;
	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
	struct msdos_dir_entry *de;
	int err, free_slots, i, nr_bhs;
	loff_t pos, i_pos;

	sinfo->nr_slots = nr_slots;

	/* First stage: search free direcotry entries */
	free_slots = nr_bhs = 0;
	bh = prev = NULL;
	pos = 0;
	err = -ENOSPC;
	while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
		/* check the maximum size of directory */
		if (pos >= FAT_MAX_DIR_SIZE)
			goto error;

		if (IS_FREE(de->name)) {
			if (prev != bh) {
				get_bh(bh);
				bhs[nr_bhs] = prev = bh;
				nr_bhs++;
			}
			free_slots++;
			if (free_slots == nr_slots)
				goto found;
		} else {
			for (i = 0; i < nr_bhs; i++)
				brelse(bhs[i]);
			prev = NULL;
			free_slots = nr_bhs = 0;
		}
	}
	if (dir->i_ino == MSDOS_ROOT_INO) {
		if (sbi->fat_bits != 32)
			goto error;
	} else if (MSDOS_I(dir)->i_start == 0) {
		printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
		       MSDOS_I(dir)->i_pos);
		err = -EIO;
		goto error;
	}

found:
	err = 0;
	pos -= free_slots * sizeof(*de);
	nr_slots -= free_slots;
	if (free_slots) {
		/*
		 * Second stage: filling the free entries with new entries.
		 * NOTE: If this slots has shortname, first, we write
		 * the long name slots, then write the short name.
		 */
		int size = free_slots * sizeof(*de);
		int offset = pos & (sb->s_blocksize - 1);
		int long_bhs = nr_bhs - (nr_slots == 0);

		/* Fill the long name slots. */
		for (i = 0; i < long_bhs; i++) {
			int copy = min_t(int, sb->s_blocksize - offset, size);
			memcpy(bhs[i]->b_data + offset, slots, copy);
			mark_buffer_dirty(bhs[i]);
			offset = 0;
			slots += copy;
			size -= copy;
		}
		if (long_bhs && IS_DIRSYNC(dir))
			err = fat_sync_bhs(bhs, long_bhs);
		if (!err && i < nr_bhs) {
			/* Fill the short name slot. */
			int copy = min_t(int, sb->s_blocksize - offset, size);
			memcpy(bhs[i]->b_data + offset, slots, copy);
			mark_buffer_dirty(bhs[i]);
			if (IS_DIRSYNC(dir))
				err = sync_dirty_buffer(bhs[i]);
		}
		for (i = 0; i < nr_bhs; i++)
			brelse(bhs[i]);
		if (err)
			goto error_remove;
	}

	if (nr_slots) {
		int cluster, nr_cluster;

		/*
		 * Third stage: allocate the cluster for new entries.
		 * And initialize the cluster with new entries, then
		 * add the cluster to dir.
		 */
		cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
					      &de, &bh, &i_pos);
		if (cluster < 0) {
			err = cluster;
			goto error_remove;
		}
		err = fat_chain_add(dir, cluster, nr_cluster);
		if (err) {
			fat_free_clusters(dir, cluster);
			goto error_remove;
		}
		if (dir->i_size & (sbi->cluster_size - 1)) {
			fat_fs_panic(sb, "Odd directory size");
			dir->i_size = (dir->i_size + sbi->cluster_size - 1)
				& ~((loff_t)sbi->cluster_size - 1);
		}
		dir->i_size += nr_cluster << sbi->cluster_bits;
		MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
	}
	sinfo->slot_off = pos;
	sinfo->de = de;
	sinfo->bh = bh;
	sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);

	return 0;

error:
	brelse(bh);
	for (i = 0; i < nr_bhs; i++)
		brelse(bhs[i]);
	return err;

error_remove:
	brelse(bh);
	if (free_slots)
		__fat_remove_entries(dir, pos, free_slots);
	return err;
}

1323
EXPORT_SYMBOL_GPL(fat_add_entries);