xref: /openbmc/linux/fs/udf/namei.c (revision fe2ead24)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * namei.c
4  *
5  * PURPOSE
6  *      Inode name handling routines for the OSTA-UDF(tm) filesystem.
7  *
8  * COPYRIGHT
9  *  (C) 1998-2004 Ben Fennema
10  *  (C) 1999-2000 Stelias Computing Inc
11  *
12  * HISTORY
13  *
14  *  12/12/98 blf  Created. Split out the lookup code from dir.c
15  *  04/19/99 blf  link, mknod, symlink support
16  */
17 
18 #include "udfdecl.h"
19 
20 #include "udf_i.h"
21 #include "udf_sb.h"
22 #include <linux/string.h>
23 #include <linux/errno.h>
24 #include <linux/mm.h>
25 #include <linux/slab.h>
26 #include <linux/sched.h>
27 #include <linux/crc-itu-t.h>
28 #include <linux/exportfs.h>
29 #include <linux/iversion.h>
30 
udf_match(int len1,const unsigned char * name1,int len2,const unsigned char * name2)31 static inline int udf_match(int len1, const unsigned char *name1, int len2,
32 			    const unsigned char *name2)
33 {
34 	if (len1 != len2)
35 		return 0;
36 
37 	return !memcmp(name1, name2, len1);
38 }
39 
40 /**
41  * udf_fiiter_find_entry - find entry in given directory.
42  *
43  * @dir:	directory inode to search in
44  * @child:	qstr of the name
45  * @iter:	iter to use for searching
46  *
47  * This function searches in the directory @dir for a file name @child. When
48  * found, @iter points to the position in the directory with given entry.
49  *
50  * Returns 0 on success, < 0 on error (including -ENOENT).
51  */
udf_fiiter_find_entry(struct inode * dir,const struct qstr * child,struct udf_fileident_iter * iter)52 static int udf_fiiter_find_entry(struct inode *dir, const struct qstr *child,
53 				 struct udf_fileident_iter *iter)
54 {
55 	int flen;
56 	unsigned char *fname = NULL;
57 	struct super_block *sb = dir->i_sb;
58 	int isdotdot = child->len == 2 &&
59 		child->name[0] == '.' && child->name[1] == '.';
60 	int ret;
61 
62 	fname = kmalloc(UDF_NAME_LEN, GFP_NOFS);
63 	if (!fname)
64 		return -ENOMEM;
65 
66 	for (ret = udf_fiiter_init(iter, dir, 0);
67 	     !ret && iter->pos < dir->i_size;
68 	     ret = udf_fiiter_advance(iter)) {
69 		if (iter->fi.fileCharacteristics & FID_FILE_CHAR_DELETED) {
70 			if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE))
71 				continue;
72 		}
73 
74 		if (iter->fi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) {
75 			if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE))
76 				continue;
77 		}
78 
79 		if ((iter->fi.fileCharacteristics & FID_FILE_CHAR_PARENT) &&
80 		    isdotdot)
81 			goto out_ok;
82 
83 		if (!iter->fi.lengthFileIdent)
84 			continue;
85 
86 		flen = udf_get_filename(sb, iter->name,
87 				iter->fi.lengthFileIdent, fname, UDF_NAME_LEN);
88 		if (flen < 0) {
89 			ret = flen;
90 			goto out_err;
91 		}
92 
93 		if (udf_match(flen, fname, child->len, child->name))
94 			goto out_ok;
95 	}
96 	if (!ret)
97 		ret = -ENOENT;
98 
99 out_err:
100 	udf_fiiter_release(iter);
101 out_ok:
102 	kfree(fname);
103 
104 	return ret;
105 }
106 
udf_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)107 static struct dentry *udf_lookup(struct inode *dir, struct dentry *dentry,
108 				 unsigned int flags)
109 {
110 	struct inode *inode = NULL;
111 	struct udf_fileident_iter iter;
112 	int err;
113 
114 	if (dentry->d_name.len > UDF_NAME_LEN)
115 		return ERR_PTR(-ENAMETOOLONG);
116 
117 	err = udf_fiiter_find_entry(dir, &dentry->d_name, &iter);
118 	if (err < 0 && err != -ENOENT)
119 		return ERR_PTR(err);
120 
121 	if (err == 0) {
122 		struct kernel_lb_addr loc;
123 
124 		loc = lelb_to_cpu(iter.fi.icb.extLocation);
125 		udf_fiiter_release(&iter);
126 
127 		inode = udf_iget(dir->i_sb, &loc);
128 		if (IS_ERR(inode))
129 			return ERR_CAST(inode);
130 	}
131 
132 	return d_splice_alias(inode, dentry);
133 }
134 
udf_expand_dir_adinicb(struct inode * inode,udf_pblk_t * block)135 static int udf_expand_dir_adinicb(struct inode *inode, udf_pblk_t *block)
136 {
137 	udf_pblk_t newblock;
138 	struct buffer_head *dbh = NULL;
139 	struct kernel_lb_addr eloc;
140 	struct extent_position epos;
141 	uint8_t alloctype;
142 	struct udf_inode_info *iinfo = UDF_I(inode);
143 	struct udf_fileident_iter iter;
144 	uint8_t *impuse;
145 	int ret;
146 
147 	if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
148 		alloctype = ICBTAG_FLAG_AD_SHORT;
149 	else
150 		alloctype = ICBTAG_FLAG_AD_LONG;
151 
152 	if (!inode->i_size) {
153 		iinfo->i_alloc_type = alloctype;
154 		mark_inode_dirty(inode);
155 		return 0;
156 	}
157 
158 	/* alloc block, and copy data to it */
159 	*block = udf_new_block(inode->i_sb, inode,
160 			       iinfo->i_location.partitionReferenceNum,
161 			       iinfo->i_location.logicalBlockNum, &ret);
162 	if (!(*block))
163 		return ret;
164 	newblock = udf_get_pblock(inode->i_sb, *block,
165 				  iinfo->i_location.partitionReferenceNum,
166 				0);
167 	if (newblock == 0xffffffff)
168 		return -EFSCORRUPTED;
169 	dbh = sb_getblk(inode->i_sb, newblock);
170 	if (!dbh)
171 		return -ENOMEM;
172 	lock_buffer(dbh);
173 	memcpy(dbh->b_data, iinfo->i_data, inode->i_size);
174 	memset(dbh->b_data + inode->i_size, 0,
175 	       inode->i_sb->s_blocksize - inode->i_size);
176 	set_buffer_uptodate(dbh);
177 	unlock_buffer(dbh);
178 
179 	/* Drop inline data, add block instead */
180 	iinfo->i_alloc_type = alloctype;
181 	memset(iinfo->i_data + iinfo->i_lenEAttr, 0, iinfo->i_lenAlloc);
182 	iinfo->i_lenAlloc = 0;
183 	eloc.logicalBlockNum = *block;
184 	eloc.partitionReferenceNum =
185 				iinfo->i_location.partitionReferenceNum;
186 	iinfo->i_lenExtents = inode->i_size;
187 	epos.bh = NULL;
188 	epos.block = iinfo->i_location;
189 	epos.offset = udf_file_entry_alloc_offset(inode);
190 	ret = udf_add_aext(inode, &epos, &eloc, inode->i_size, 0);
191 	brelse(epos.bh);
192 	if (ret < 0) {
193 		brelse(dbh);
194 		udf_free_blocks(inode->i_sb, inode, &eloc, 0, 1);
195 		return ret;
196 	}
197 	mark_inode_dirty(inode);
198 
199 	/* Now fixup tags in moved directory entries */
200 	for (ret = udf_fiiter_init(&iter, inode, 0);
201 	     !ret && iter.pos < inode->i_size;
202 	     ret = udf_fiiter_advance(&iter)) {
203 		iter.fi.descTag.tagLocation = cpu_to_le32(*block);
204 		if (iter.fi.lengthOfImpUse != cpu_to_le16(0))
205 			impuse = dbh->b_data + iter.pos +
206 						sizeof(struct fileIdentDesc);
207 		else
208 			impuse = NULL;
209 		udf_fiiter_write_fi(&iter, impuse);
210 	}
211 	brelse(dbh);
212 	/*
213 	 * We don't expect the iteration to fail as the directory has been
214 	 * already verified to be correct
215 	 */
216 	WARN_ON_ONCE(ret);
217 	udf_fiiter_release(&iter);
218 
219 	return 0;
220 }
221 
udf_fiiter_add_entry(struct inode * dir,struct dentry * dentry,struct udf_fileident_iter * iter)222 static int udf_fiiter_add_entry(struct inode *dir, struct dentry *dentry,
223 				struct udf_fileident_iter *iter)
224 {
225 	struct udf_inode_info *dinfo = UDF_I(dir);
226 	int nfidlen, namelen = 0;
227 	int ret;
228 	int off, blksize = 1 << dir->i_blkbits;
229 	udf_pblk_t block;
230 	char name[UDF_NAME_LEN_CS0];
231 
232 	if (dentry) {
233 		if (!dentry->d_name.len)
234 			return -EINVAL;
235 		namelen = udf_put_filename(dir->i_sb, dentry->d_name.name,
236 					   dentry->d_name.len,
237 					   name, UDF_NAME_LEN_CS0);
238 		if (!namelen)
239 			return -ENAMETOOLONG;
240 	}
241 	nfidlen = ALIGN(sizeof(struct fileIdentDesc) + namelen, UDF_NAME_PAD);
242 
243 	for (ret = udf_fiiter_init(iter, dir, 0);
244 	     !ret && iter->pos < dir->i_size;
245 	     ret = udf_fiiter_advance(iter)) {
246 		if (iter->fi.fileCharacteristics & FID_FILE_CHAR_DELETED) {
247 			if (udf_dir_entry_len(&iter->fi) == nfidlen) {
248 				iter->fi.descTag.tagSerialNum = cpu_to_le16(1);
249 				iter->fi.fileVersionNum = cpu_to_le16(1);
250 				iter->fi.fileCharacteristics = 0;
251 				iter->fi.lengthFileIdent = namelen;
252 				iter->fi.lengthOfImpUse = cpu_to_le16(0);
253 				memcpy(iter->namebuf, name, namelen);
254 				iter->name = iter->namebuf;
255 				return 0;
256 			}
257 		}
258 	}
259 	if (ret) {
260 		udf_fiiter_release(iter);
261 		return ret;
262 	}
263 	if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB &&
264 	    blksize - udf_ext0_offset(dir) - iter->pos < nfidlen) {
265 		udf_fiiter_release(iter);
266 		ret = udf_expand_dir_adinicb(dir, &block);
267 		if (ret)
268 			return ret;
269 		ret = udf_fiiter_init(iter, dir, dir->i_size);
270 		if (ret < 0)
271 			return ret;
272 	}
273 
274 	/* Get blocknumber to use for entry tag */
275 	if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
276 		block = dinfo->i_location.logicalBlockNum;
277 	} else {
278 		block = iter->eloc.logicalBlockNum +
279 				((iter->elen - 1) >> dir->i_blkbits);
280 	}
281 	off = iter->pos & (blksize - 1);
282 	if (!off)
283 		off = blksize;
284 	/* Entry fits into current block? */
285 	if (blksize - udf_ext0_offset(dir) - off >= nfidlen)
286 		goto store_fi;
287 
288 	ret = udf_fiiter_append_blk(iter);
289 	if (ret) {
290 		udf_fiiter_release(iter);
291 		return ret;
292 	}
293 
294 	/* Entry will be completely in the new block? Update tag location... */
295 	if (!(iter->pos & (blksize - 1)))
296 		block = iter->eloc.logicalBlockNum +
297 				((iter->elen - 1) >> dir->i_blkbits);
298 store_fi:
299 	memset(&iter->fi, 0, sizeof(struct fileIdentDesc));
300 	if (UDF_SB(dir->i_sb)->s_udfrev >= 0x0200)
301 		udf_new_tag((char *)(&iter->fi), TAG_IDENT_FID, 3, 1, block,
302 			    sizeof(struct tag));
303 	else
304 		udf_new_tag((char *)(&iter->fi), TAG_IDENT_FID, 2, 1, block,
305 			    sizeof(struct tag));
306 	iter->fi.fileVersionNum = cpu_to_le16(1);
307 	iter->fi.lengthFileIdent = namelen;
308 	iter->fi.lengthOfImpUse = cpu_to_le16(0);
309 	memcpy(iter->namebuf, name, namelen);
310 	iter->name = iter->namebuf;
311 
312 	dir->i_size += nfidlen;
313 	if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
314 		dinfo->i_lenAlloc += nfidlen;
315 	} else {
316 		/* Truncate last extent to proper size */
317 		udf_fiiter_update_elen(iter, iter->elen -
318 					(dinfo->i_lenExtents - dir->i_size));
319 	}
320 	mark_inode_dirty(dir);
321 
322 	return 0;
323 }
324 
udf_fiiter_delete_entry(struct udf_fileident_iter * iter)325 static void udf_fiiter_delete_entry(struct udf_fileident_iter *iter)
326 {
327 	iter->fi.fileCharacteristics |= FID_FILE_CHAR_DELETED;
328 
329 	if (UDF_QUERY_FLAG(iter->dir->i_sb, UDF_FLAG_STRICT))
330 		memset(&iter->fi.icb, 0x00, sizeof(struct long_ad));
331 
332 	udf_fiiter_write_fi(iter, NULL);
333 }
334 
udf_add_fid_counter(struct super_block * sb,bool dir,int val)335 static void udf_add_fid_counter(struct super_block *sb, bool dir, int val)
336 {
337 	struct logicalVolIntegrityDescImpUse *lvidiu = udf_sb_lvidiu(sb);
338 
339 	if (!lvidiu)
340 		return;
341 	mutex_lock(&UDF_SB(sb)->s_alloc_mutex);
342 	if (dir)
343 		le32_add_cpu(&lvidiu->numDirs, val);
344 	else
345 		le32_add_cpu(&lvidiu->numFiles, val);
346 	udf_updated_lvid(sb);
347 	mutex_unlock(&UDF_SB(sb)->s_alloc_mutex);
348 }
349 
udf_add_nondir(struct dentry * dentry,struct inode * inode)350 static int udf_add_nondir(struct dentry *dentry, struct inode *inode)
351 {
352 	struct udf_inode_info *iinfo = UDF_I(inode);
353 	struct inode *dir = d_inode(dentry->d_parent);
354 	struct udf_fileident_iter iter;
355 	int err;
356 
357 	err = udf_fiiter_add_entry(dir, dentry, &iter);
358 	if (err) {
359 		inode_dec_link_count(inode);
360 		discard_new_inode(inode);
361 		return err;
362 	}
363 	iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
364 	iter.fi.icb.extLocation = cpu_to_lelb(iinfo->i_location);
365 	*(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
366 		cpu_to_le32(iinfo->i_unique & 0x00000000FFFFFFFFUL);
367 	udf_fiiter_write_fi(&iter, NULL);
368 	dir->i_mtime = inode_set_ctime_current(dir);
369 	mark_inode_dirty(dir);
370 	udf_fiiter_release(&iter);
371 	udf_add_fid_counter(dir->i_sb, false, 1);
372 	d_instantiate_new(dentry, inode);
373 
374 	return 0;
375 }
376 
udf_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)377 static int udf_create(struct mnt_idmap *idmap, struct inode *dir,
378 		      struct dentry *dentry, umode_t mode, bool excl)
379 {
380 	struct inode *inode = udf_new_inode(dir, mode);
381 
382 	if (IS_ERR(inode))
383 		return PTR_ERR(inode);
384 
385 	inode->i_data.a_ops = &udf_aops;
386 	inode->i_op = &udf_file_inode_operations;
387 	inode->i_fop = &udf_file_operations;
388 	mark_inode_dirty(inode);
389 
390 	return udf_add_nondir(dentry, inode);
391 }
392 
udf_tmpfile(struct mnt_idmap * idmap,struct inode * dir,struct file * file,umode_t mode)393 static int udf_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
394 		       struct file *file, umode_t mode)
395 {
396 	struct inode *inode = udf_new_inode(dir, mode);
397 
398 	if (IS_ERR(inode))
399 		return PTR_ERR(inode);
400 
401 	inode->i_data.a_ops = &udf_aops;
402 	inode->i_op = &udf_file_inode_operations;
403 	inode->i_fop = &udf_file_operations;
404 	mark_inode_dirty(inode);
405 	d_tmpfile(file, inode);
406 	unlock_new_inode(inode);
407 	return finish_open_simple(file, 0);
408 }
409 
udf_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)410 static int udf_mknod(struct mnt_idmap *idmap, struct inode *dir,
411 		     struct dentry *dentry, umode_t mode, dev_t rdev)
412 {
413 	struct inode *inode;
414 
415 	if (!old_valid_dev(rdev))
416 		return -EINVAL;
417 
418 	inode = udf_new_inode(dir, mode);
419 	if (IS_ERR(inode))
420 		return PTR_ERR(inode);
421 
422 	init_special_inode(inode, mode, rdev);
423 	return udf_add_nondir(dentry, inode);
424 }
425 
udf_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)426 static int udf_mkdir(struct mnt_idmap *idmap, struct inode *dir,
427 		     struct dentry *dentry, umode_t mode)
428 {
429 	struct inode *inode;
430 	struct udf_fileident_iter iter;
431 	int err;
432 	struct udf_inode_info *dinfo = UDF_I(dir);
433 	struct udf_inode_info *iinfo;
434 
435 	inode = udf_new_inode(dir, S_IFDIR | mode);
436 	if (IS_ERR(inode))
437 		return PTR_ERR(inode);
438 
439 	iinfo = UDF_I(inode);
440 	inode->i_op = &udf_dir_inode_operations;
441 	inode->i_fop = &udf_dir_operations;
442 	err = udf_fiiter_add_entry(inode, NULL, &iter);
443 	if (err) {
444 		clear_nlink(inode);
445 		discard_new_inode(inode);
446 		return err;
447 	}
448 	set_nlink(inode, 2);
449 	iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
450 	iter.fi.icb.extLocation = cpu_to_lelb(dinfo->i_location);
451 	*(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
452 		cpu_to_le32(dinfo->i_unique & 0x00000000FFFFFFFFUL);
453 	iter.fi.fileCharacteristics =
454 			FID_FILE_CHAR_DIRECTORY | FID_FILE_CHAR_PARENT;
455 	udf_fiiter_write_fi(&iter, NULL);
456 	udf_fiiter_release(&iter);
457 	mark_inode_dirty(inode);
458 
459 	err = udf_fiiter_add_entry(dir, dentry, &iter);
460 	if (err) {
461 		clear_nlink(inode);
462 		discard_new_inode(inode);
463 		return err;
464 	}
465 	iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
466 	iter.fi.icb.extLocation = cpu_to_lelb(iinfo->i_location);
467 	*(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
468 		cpu_to_le32(iinfo->i_unique & 0x00000000FFFFFFFFUL);
469 	iter.fi.fileCharacteristics |= FID_FILE_CHAR_DIRECTORY;
470 	udf_fiiter_write_fi(&iter, NULL);
471 	udf_fiiter_release(&iter);
472 	udf_add_fid_counter(dir->i_sb, true, 1);
473 	inc_nlink(dir);
474 	dir->i_mtime = inode_set_ctime_current(dir);
475 	mark_inode_dirty(dir);
476 	d_instantiate_new(dentry, inode);
477 
478 	return 0;
479 }
480 
empty_dir(struct inode * dir)481 static int empty_dir(struct inode *dir)
482 {
483 	struct udf_fileident_iter iter;
484 	int ret;
485 
486 	for (ret = udf_fiiter_init(&iter, dir, 0);
487 	     !ret && iter.pos < dir->i_size;
488 	     ret = udf_fiiter_advance(&iter)) {
489 		if (iter.fi.lengthFileIdent &&
490 		    !(iter.fi.fileCharacteristics & FID_FILE_CHAR_DELETED)) {
491 			udf_fiiter_release(&iter);
492 			return 0;
493 		}
494 	}
495 	udf_fiiter_release(&iter);
496 
497 	return 1;
498 }
499 
udf_rmdir(struct inode * dir,struct dentry * dentry)500 static int udf_rmdir(struct inode *dir, struct dentry *dentry)
501 {
502 	int ret;
503 	struct inode *inode = d_inode(dentry);
504 	struct udf_fileident_iter iter;
505 	struct kernel_lb_addr tloc;
506 
507 	ret = udf_fiiter_find_entry(dir, &dentry->d_name, &iter);
508 	if (ret)
509 		goto out;
510 
511 	ret = -EFSCORRUPTED;
512 	tloc = lelb_to_cpu(iter.fi.icb.extLocation);
513 	if (udf_get_lb_pblock(dir->i_sb, &tloc, 0) != inode->i_ino)
514 		goto end_rmdir;
515 	ret = -ENOTEMPTY;
516 	if (!empty_dir(inode))
517 		goto end_rmdir;
518 	udf_fiiter_delete_entry(&iter);
519 	if (inode->i_nlink != 2)
520 		udf_warn(inode->i_sb, "empty directory has nlink != 2 (%u)\n",
521 			 inode->i_nlink);
522 	clear_nlink(inode);
523 	inode->i_size = 0;
524 	inode_dec_link_count(dir);
525 	udf_add_fid_counter(dir->i_sb, true, -1);
526 	dir->i_mtime = inode_set_ctime_to_ts(dir,
527 					     inode_set_ctime_current(inode));
528 	mark_inode_dirty(dir);
529 	ret = 0;
530 end_rmdir:
531 	udf_fiiter_release(&iter);
532 out:
533 	return ret;
534 }
535 
udf_unlink(struct inode * dir,struct dentry * dentry)536 static int udf_unlink(struct inode *dir, struct dentry *dentry)
537 {
538 	int ret;
539 	struct inode *inode = d_inode(dentry);
540 	struct udf_fileident_iter iter;
541 	struct kernel_lb_addr tloc;
542 
543 	ret = udf_fiiter_find_entry(dir, &dentry->d_name, &iter);
544 	if (ret)
545 		goto out;
546 
547 	ret = -EFSCORRUPTED;
548 	tloc = lelb_to_cpu(iter.fi.icb.extLocation);
549 	if (udf_get_lb_pblock(dir->i_sb, &tloc, 0) != inode->i_ino)
550 		goto end_unlink;
551 
552 	if (!inode->i_nlink) {
553 		udf_debug("Deleting nonexistent file (%lu), %u\n",
554 			  inode->i_ino, inode->i_nlink);
555 		set_nlink(inode, 1);
556 	}
557 	udf_fiiter_delete_entry(&iter);
558 	dir->i_mtime = inode_set_ctime_current(dir);
559 	mark_inode_dirty(dir);
560 	inode_dec_link_count(inode);
561 	udf_add_fid_counter(dir->i_sb, false, -1);
562 	inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
563 	ret = 0;
564 end_unlink:
565 	udf_fiiter_release(&iter);
566 out:
567 	return ret;
568 }
569 
udf_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * symname)570 static int udf_symlink(struct mnt_idmap *idmap, struct inode *dir,
571 		       struct dentry *dentry, const char *symname)
572 {
573 	struct inode *inode = udf_new_inode(dir, S_IFLNK | 0777);
574 	struct pathComponent *pc;
575 	const char *compstart;
576 	struct extent_position epos = {};
577 	int eoffset, elen = 0;
578 	uint8_t *ea;
579 	int err;
580 	udf_pblk_t block;
581 	unsigned char *name = NULL;
582 	int namelen;
583 	struct udf_inode_info *iinfo;
584 	struct super_block *sb = dir->i_sb;
585 
586 	if (IS_ERR(inode))
587 		return PTR_ERR(inode);
588 
589 	iinfo = UDF_I(inode);
590 	down_write(&iinfo->i_data_sem);
591 	name = kmalloc(UDF_NAME_LEN_CS0, GFP_NOFS);
592 	if (!name) {
593 		err = -ENOMEM;
594 		goto out_no_entry;
595 	}
596 
597 	inode->i_data.a_ops = &udf_symlink_aops;
598 	inode->i_op = &udf_symlink_inode_operations;
599 	inode_nohighmem(inode);
600 
601 	if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
602 		struct kernel_lb_addr eloc;
603 		uint32_t bsize;
604 
605 		block = udf_new_block(sb, inode,
606 				iinfo->i_location.partitionReferenceNum,
607 				iinfo->i_location.logicalBlockNum, &err);
608 		if (!block)
609 			goto out_no_entry;
610 		epos.block = iinfo->i_location;
611 		epos.offset = udf_file_entry_alloc_offset(inode);
612 		epos.bh = NULL;
613 		eloc.logicalBlockNum = block;
614 		eloc.partitionReferenceNum =
615 				iinfo->i_location.partitionReferenceNum;
616 		bsize = sb->s_blocksize;
617 		iinfo->i_lenExtents = bsize;
618 		err = udf_add_aext(inode, &epos, &eloc, bsize, 0);
619 		brelse(epos.bh);
620 		if (err < 0) {
621 			udf_free_blocks(sb, inode, &eloc, 0, 1);
622 			goto out_no_entry;
623 		}
624 
625 		block = udf_get_pblock(sb, block,
626 				iinfo->i_location.partitionReferenceNum,
627 				0);
628 		epos.bh = sb_getblk(sb, block);
629 		if (unlikely(!epos.bh)) {
630 			err = -ENOMEM;
631 			udf_free_blocks(sb, inode, &eloc, 0, 1);
632 			goto out_no_entry;
633 		}
634 		lock_buffer(epos.bh);
635 		memset(epos.bh->b_data, 0x00, bsize);
636 		set_buffer_uptodate(epos.bh);
637 		unlock_buffer(epos.bh);
638 		mark_buffer_dirty_inode(epos.bh, inode);
639 		ea = epos.bh->b_data + udf_ext0_offset(inode);
640 	} else
641 		ea = iinfo->i_data + iinfo->i_lenEAttr;
642 
643 	eoffset = sb->s_blocksize - udf_ext0_offset(inode);
644 	pc = (struct pathComponent *)ea;
645 
646 	if (*symname == '/') {
647 		do {
648 			symname++;
649 		} while (*symname == '/');
650 
651 		pc->componentType = 1;
652 		pc->lengthComponentIdent = 0;
653 		pc->componentFileVersionNum = 0;
654 		elen += sizeof(struct pathComponent);
655 	}
656 
657 	err = -ENAMETOOLONG;
658 
659 	while (*symname) {
660 		if (elen + sizeof(struct pathComponent) > eoffset)
661 			goto out_no_entry;
662 
663 		pc = (struct pathComponent *)(ea + elen);
664 
665 		compstart = symname;
666 
667 		do {
668 			symname++;
669 		} while (*symname && *symname != '/');
670 
671 		pc->componentType = 5;
672 		pc->lengthComponentIdent = 0;
673 		pc->componentFileVersionNum = 0;
674 		if (compstart[0] == '.') {
675 			if ((symname - compstart) == 1)
676 				pc->componentType = 4;
677 			else if ((symname - compstart) == 2 &&
678 					compstart[1] == '.')
679 				pc->componentType = 3;
680 		}
681 
682 		if (pc->componentType == 5) {
683 			namelen = udf_put_filename(sb, compstart,
684 						   symname - compstart,
685 						   name, UDF_NAME_LEN_CS0);
686 			if (!namelen)
687 				goto out_no_entry;
688 
689 			if (elen + sizeof(struct pathComponent) + namelen >
690 					eoffset)
691 				goto out_no_entry;
692 			else
693 				pc->lengthComponentIdent = namelen;
694 
695 			memcpy(pc->componentIdent, name, namelen);
696 		}
697 
698 		elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
699 
700 		if (*symname) {
701 			do {
702 				symname++;
703 			} while (*symname == '/');
704 		}
705 	}
706 
707 	brelse(epos.bh);
708 	inode->i_size = elen;
709 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
710 		iinfo->i_lenAlloc = inode->i_size;
711 	else
712 		udf_truncate_tail_extent(inode);
713 	mark_inode_dirty(inode);
714 	up_write(&iinfo->i_data_sem);
715 
716 	err = udf_add_nondir(dentry, inode);
717 out:
718 	kfree(name);
719 	return err;
720 
721 out_no_entry:
722 	up_write(&iinfo->i_data_sem);
723 	inode_dec_link_count(inode);
724 	discard_new_inode(inode);
725 	goto out;
726 }
727 
udf_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)728 static int udf_link(struct dentry *old_dentry, struct inode *dir,
729 		    struct dentry *dentry)
730 {
731 	struct inode *inode = d_inode(old_dentry);
732 	struct udf_fileident_iter iter;
733 	int err;
734 
735 	err = udf_fiiter_add_entry(dir, dentry, &iter);
736 	if (err)
737 		return err;
738 	iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
739 	iter.fi.icb.extLocation = cpu_to_lelb(UDF_I(inode)->i_location);
740 	if (UDF_SB(inode->i_sb)->s_lvid_bh) {
741 		*(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
742 			cpu_to_le32(lvid_get_unique_id(inode->i_sb));
743 	}
744 	udf_fiiter_write_fi(&iter, NULL);
745 	udf_fiiter_release(&iter);
746 
747 	inc_nlink(inode);
748 	udf_add_fid_counter(dir->i_sb, false, 1);
749 	inode_set_ctime_current(inode);
750 	mark_inode_dirty(inode);
751 	dir->i_mtime = inode_set_ctime_current(dir);
752 	mark_inode_dirty(dir);
753 	ihold(inode);
754 	d_instantiate(dentry, inode);
755 
756 	return 0;
757 }
758 
759 /* Anybody can rename anything with this: the permission checks are left to the
760  * higher-level routines.
761  */
udf_rename(struct mnt_idmap * idmap,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)762 static int udf_rename(struct mnt_idmap *idmap, struct inode *old_dir,
763 		      struct dentry *old_dentry, struct inode *new_dir,
764 		      struct dentry *new_dentry, unsigned int flags)
765 {
766 	struct inode *old_inode = d_inode(old_dentry);
767 	struct inode *new_inode = d_inode(new_dentry);
768 	struct udf_fileident_iter oiter, niter, diriter;
769 	bool has_diriter = false;
770 	int retval;
771 	struct kernel_lb_addr tloc;
772 
773 	if (flags & ~RENAME_NOREPLACE)
774 		return -EINVAL;
775 
776 	retval = udf_fiiter_find_entry(old_dir, &old_dentry->d_name, &oiter);
777 	if (retval)
778 		return retval;
779 
780 	tloc = lelb_to_cpu(oiter.fi.icb.extLocation);
781 	if (udf_get_lb_pblock(old_dir->i_sb, &tloc, 0) != old_inode->i_ino) {
782 		retval = -ENOENT;
783 		goto out_oiter;
784 	}
785 
786 	if (S_ISDIR(old_inode->i_mode)) {
787 		if (new_inode) {
788 			retval = -ENOTEMPTY;
789 			if (!empty_dir(new_inode))
790 				goto out_oiter;
791 		}
792 		retval = udf_fiiter_find_entry(old_inode, &dotdot_name,
793 					       &diriter);
794 		if (retval == -ENOENT) {
795 			udf_err(old_inode->i_sb,
796 				"directory (ino %lu) has no '..' entry\n",
797 				old_inode->i_ino);
798 			retval = -EFSCORRUPTED;
799 		}
800 		if (retval)
801 			goto out_oiter;
802 		has_diriter = true;
803 		tloc = lelb_to_cpu(diriter.fi.icb.extLocation);
804 		if (udf_get_lb_pblock(old_inode->i_sb, &tloc, 0) !=
805 				old_dir->i_ino) {
806 			retval = -EFSCORRUPTED;
807 			udf_err(old_inode->i_sb,
808 				"directory (ino %lu) has parent entry pointing to another inode (%lu != %u)\n",
809 				old_inode->i_ino, old_dir->i_ino,
810 				udf_get_lb_pblock(old_inode->i_sb, &tloc, 0));
811 			goto out_oiter;
812 		}
813 	}
814 
815 	retval = udf_fiiter_find_entry(new_dir, &new_dentry->d_name, &niter);
816 	if (retval && retval != -ENOENT)
817 		goto out_oiter;
818 	/* Entry found but not passed by VFS? */
819 	if (!retval && !new_inode) {
820 		retval = -EFSCORRUPTED;
821 		udf_fiiter_release(&niter);
822 		goto out_oiter;
823 	}
824 	/* Entry not found? Need to add one... */
825 	if (retval) {
826 		udf_fiiter_release(&niter);
827 		retval = udf_fiiter_add_entry(new_dir, new_dentry, &niter);
828 		if (retval)
829 			goto out_oiter;
830 	}
831 
832 	/*
833 	 * Like most other Unix systems, set the ctime for inodes on a
834 	 * rename.
835 	 */
836 	inode_set_ctime_current(old_inode);
837 	mark_inode_dirty(old_inode);
838 
839 	/*
840 	 * ok, that's it
841 	 */
842 	niter.fi.fileVersionNum = oiter.fi.fileVersionNum;
843 	niter.fi.fileCharacteristics = oiter.fi.fileCharacteristics;
844 	memcpy(&(niter.fi.icb), &(oiter.fi.icb), sizeof(oiter.fi.icb));
845 	udf_fiiter_write_fi(&niter, NULL);
846 	udf_fiiter_release(&niter);
847 
848 	/*
849 	 * The old entry may have moved due to new entry allocation. Find it
850 	 * again.
851 	 */
852 	udf_fiiter_release(&oiter);
853 	retval = udf_fiiter_find_entry(old_dir, &old_dentry->d_name, &oiter);
854 	if (retval) {
855 		udf_err(old_dir->i_sb,
856 			"failed to find renamed entry again in directory (ino %lu)\n",
857 			old_dir->i_ino);
858 	} else {
859 		udf_fiiter_delete_entry(&oiter);
860 		udf_fiiter_release(&oiter);
861 	}
862 
863 	if (new_inode) {
864 		inode_set_ctime_current(new_inode);
865 		inode_dec_link_count(new_inode);
866 		udf_add_fid_counter(old_dir->i_sb, S_ISDIR(new_inode->i_mode),
867 				    -1);
868 	}
869 	old_dir->i_mtime = inode_set_ctime_current(old_dir);
870 	new_dir->i_mtime = inode_set_ctime_current(new_dir);
871 	mark_inode_dirty(old_dir);
872 	mark_inode_dirty(new_dir);
873 
874 	if (has_diriter) {
875 		diriter.fi.icb.extLocation =
876 					cpu_to_lelb(UDF_I(new_dir)->i_location);
877 		udf_fiiter_write_fi(&diriter, NULL);
878 		udf_fiiter_release(&diriter);
879 
880 		inode_dec_link_count(old_dir);
881 		if (new_inode)
882 			inode_dec_link_count(new_inode);
883 		else {
884 			inc_nlink(new_dir);
885 			mark_inode_dirty(new_dir);
886 		}
887 	}
888 	return 0;
889 out_oiter:
890 	if (has_diriter)
891 		udf_fiiter_release(&diriter);
892 	udf_fiiter_release(&oiter);
893 
894 	return retval;
895 }
896 
udf_get_parent(struct dentry * child)897 static struct dentry *udf_get_parent(struct dentry *child)
898 {
899 	struct kernel_lb_addr tloc;
900 	struct inode *inode = NULL;
901 	struct udf_fileident_iter iter;
902 	int err;
903 
904 	err = udf_fiiter_find_entry(d_inode(child), &dotdot_name, &iter);
905 	if (err)
906 		return ERR_PTR(err);
907 
908 	tloc = lelb_to_cpu(iter.fi.icb.extLocation);
909 	udf_fiiter_release(&iter);
910 	inode = udf_iget(child->d_sb, &tloc);
911 	if (IS_ERR(inode))
912 		return ERR_CAST(inode);
913 
914 	return d_obtain_alias(inode);
915 }
916 
917 
udf_nfs_get_inode(struct super_block * sb,u32 block,u16 partref,__u32 generation)918 static struct dentry *udf_nfs_get_inode(struct super_block *sb, u32 block,
919 					u16 partref, __u32 generation)
920 {
921 	struct inode *inode;
922 	struct kernel_lb_addr loc;
923 
924 	if (block == 0)
925 		return ERR_PTR(-ESTALE);
926 
927 	loc.logicalBlockNum = block;
928 	loc.partitionReferenceNum = partref;
929 	inode = udf_iget(sb, &loc);
930 
931 	if (IS_ERR(inode))
932 		return ERR_CAST(inode);
933 
934 	if (generation && inode->i_generation != generation) {
935 		iput(inode);
936 		return ERR_PTR(-ESTALE);
937 	}
938 	return d_obtain_alias(inode);
939 }
940 
udf_fh_to_dentry(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)941 static struct dentry *udf_fh_to_dentry(struct super_block *sb,
942 				       struct fid *fid, int fh_len, int fh_type)
943 {
944 	if (fh_len < 3 ||
945 	    (fh_type != FILEID_UDF_WITH_PARENT &&
946 	     fh_type != FILEID_UDF_WITHOUT_PARENT))
947 		return NULL;
948 
949 	return udf_nfs_get_inode(sb, fid->udf.block, fid->udf.partref,
950 			fid->udf.generation);
951 }
952 
udf_fh_to_parent(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)953 static struct dentry *udf_fh_to_parent(struct super_block *sb,
954 				       struct fid *fid, int fh_len, int fh_type)
955 {
956 	if (fh_len < 5 || fh_type != FILEID_UDF_WITH_PARENT)
957 		return NULL;
958 
959 	return udf_nfs_get_inode(sb, fid->udf.parent_block,
960 				 fid->udf.parent_partref,
961 				 fid->udf.parent_generation);
962 }
udf_encode_fh(struct inode * inode,__u32 * fh,int * lenp,struct inode * parent)963 static int udf_encode_fh(struct inode *inode, __u32 *fh, int *lenp,
964 			 struct inode *parent)
965 {
966 	int len = *lenp;
967 	struct kernel_lb_addr location = UDF_I(inode)->i_location;
968 	struct fid *fid = (struct fid *)fh;
969 	int type = FILEID_UDF_WITHOUT_PARENT;
970 
971 	if (parent && (len < 5)) {
972 		*lenp = 5;
973 		return FILEID_INVALID;
974 	} else if (len < 3) {
975 		*lenp = 3;
976 		return FILEID_INVALID;
977 	}
978 
979 	*lenp = 3;
980 	fid->udf.block = location.logicalBlockNum;
981 	fid->udf.partref = location.partitionReferenceNum;
982 	fid->udf.parent_partref = 0;
983 	fid->udf.generation = inode->i_generation;
984 
985 	if (parent) {
986 		location = UDF_I(parent)->i_location;
987 		fid->udf.parent_block = location.logicalBlockNum;
988 		fid->udf.parent_partref = location.partitionReferenceNum;
989 		fid->udf.parent_generation = inode->i_generation;
990 		*lenp = 5;
991 		type = FILEID_UDF_WITH_PARENT;
992 	}
993 
994 	return type;
995 }
996 
997 const struct export_operations udf_export_ops = {
998 	.encode_fh	= udf_encode_fh,
999 	.fh_to_dentry   = udf_fh_to_dentry,
1000 	.fh_to_parent   = udf_fh_to_parent,
1001 	.get_parent     = udf_get_parent,
1002 };
1003 
1004 const struct inode_operations udf_dir_inode_operations = {
1005 	.lookup				= udf_lookup,
1006 	.create				= udf_create,
1007 	.link				= udf_link,
1008 	.unlink				= udf_unlink,
1009 	.symlink			= udf_symlink,
1010 	.mkdir				= udf_mkdir,
1011 	.rmdir				= udf_rmdir,
1012 	.mknod				= udf_mknod,
1013 	.rename				= udf_rename,
1014 	.tmpfile			= udf_tmpfile,
1015 };
1016