xref: /openbmc/linux/fs/udf/inode.c (revision c67ce71d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * inode.c
4  *
5  * PURPOSE
6  *  Inode handling routines for the OSTA-UDF(tm) filesystem.
7  *
8  * COPYRIGHT
9  *  (C) 1998 Dave Boynton
10  *  (C) 1998-2004 Ben Fennema
11  *  (C) 1999-2000 Stelias Computing Inc
12  *
13  * HISTORY
14  *
15  *  10/04/98 dgb  Added rudimentary directory functions
16  *  10/07/98      Fully working udf_block_map! It works!
17  *  11/25/98      bmap altered to better support extents
18  *  12/06/98 blf  partition support in udf_iget, udf_block_map
19  *                and udf_read_inode
20  *  12/12/98      rewrote udf_block_map to handle next extents and descs across
21  *                block boundaries (which is not actually allowed)
22  *  12/20/98      added support for strategy 4096
23  *  03/07/99      rewrote udf_block_map (again)
24  *                New funcs, inode_bmap, udf_next_aext
25  *  04/19/99      Support for writing device EA's for major/minor #
26  */
27 
28 #include "udfdecl.h"
29 #include <linux/mm.h>
30 #include <linux/module.h>
31 #include <linux/pagemap.h>
32 #include <linux/writeback.h>
33 #include <linux/slab.h>
34 #include <linux/crc-itu-t.h>
35 #include <linux/mpage.h>
36 #include <linux/uio.h>
37 #include <linux/bio.h>
38 
39 #include "udf_i.h"
40 #include "udf_sb.h"
41 
42 #define EXTENT_MERGE_SIZE 5
43 
44 #define FE_MAPPED_PERMS	(FE_PERM_U_READ | FE_PERM_U_WRITE | FE_PERM_U_EXEC | \
45 			 FE_PERM_G_READ | FE_PERM_G_WRITE | FE_PERM_G_EXEC | \
46 			 FE_PERM_O_READ | FE_PERM_O_WRITE | FE_PERM_O_EXEC)
47 
48 #define FE_DELETE_PERMS	(FE_PERM_U_DELETE | FE_PERM_G_DELETE | \
49 			 FE_PERM_O_DELETE)
50 
51 struct udf_map_rq;
52 
53 static umode_t udf_convert_permissions(struct fileEntry *);
54 static int udf_update_inode(struct inode *, int);
55 static int udf_sync_inode(struct inode *inode);
56 static int udf_alloc_i_data(struct inode *inode, size_t size);
57 static int inode_getblk(struct inode *inode, struct udf_map_rq *map);
58 static int udf_insert_aext(struct inode *, struct extent_position,
59 			   struct kernel_lb_addr, uint32_t);
60 static void udf_split_extents(struct inode *, int *, int, udf_pblk_t,
61 			      struct kernel_long_ad *, int *);
62 static void udf_prealloc_extents(struct inode *, int, int,
63 				 struct kernel_long_ad *, int *);
64 static void udf_merge_extents(struct inode *, struct kernel_long_ad *, int *);
65 static int udf_update_extents(struct inode *, struct kernel_long_ad *, int,
66 			      int, struct extent_position *);
67 static int udf_get_block_wb(struct inode *inode, sector_t block,
68 			    struct buffer_head *bh_result, int create);
69 
70 static void __udf_clear_extent_cache(struct inode *inode)
71 {
72 	struct udf_inode_info *iinfo = UDF_I(inode);
73 
74 	if (iinfo->cached_extent.lstart != -1) {
75 		brelse(iinfo->cached_extent.epos.bh);
76 		iinfo->cached_extent.lstart = -1;
77 	}
78 }
79 
80 /* Invalidate extent cache */
81 static void udf_clear_extent_cache(struct inode *inode)
82 {
83 	struct udf_inode_info *iinfo = UDF_I(inode);
84 
85 	spin_lock(&iinfo->i_extent_cache_lock);
86 	__udf_clear_extent_cache(inode);
87 	spin_unlock(&iinfo->i_extent_cache_lock);
88 }
89 
90 /* Return contents of extent cache */
91 static int udf_read_extent_cache(struct inode *inode, loff_t bcount,
92 				 loff_t *lbcount, struct extent_position *pos)
93 {
94 	struct udf_inode_info *iinfo = UDF_I(inode);
95 	int ret = 0;
96 
97 	spin_lock(&iinfo->i_extent_cache_lock);
98 	if ((iinfo->cached_extent.lstart <= bcount) &&
99 	    (iinfo->cached_extent.lstart != -1)) {
100 		/* Cache hit */
101 		*lbcount = iinfo->cached_extent.lstart;
102 		memcpy(pos, &iinfo->cached_extent.epos,
103 		       sizeof(struct extent_position));
104 		if (pos->bh)
105 			get_bh(pos->bh);
106 		ret = 1;
107 	}
108 	spin_unlock(&iinfo->i_extent_cache_lock);
109 	return ret;
110 }
111 
112 /* Add extent to extent cache */
113 static void udf_update_extent_cache(struct inode *inode, loff_t estart,
114 				    struct extent_position *pos)
115 {
116 	struct udf_inode_info *iinfo = UDF_I(inode);
117 
118 	spin_lock(&iinfo->i_extent_cache_lock);
119 	/* Invalidate previously cached extent */
120 	__udf_clear_extent_cache(inode);
121 	if (pos->bh)
122 		get_bh(pos->bh);
123 	memcpy(&iinfo->cached_extent.epos, pos, sizeof(*pos));
124 	iinfo->cached_extent.lstart = estart;
125 	switch (iinfo->i_alloc_type) {
126 	case ICBTAG_FLAG_AD_SHORT:
127 		iinfo->cached_extent.epos.offset -= sizeof(struct short_ad);
128 		break;
129 	case ICBTAG_FLAG_AD_LONG:
130 		iinfo->cached_extent.epos.offset -= sizeof(struct long_ad);
131 		break;
132 	}
133 	spin_unlock(&iinfo->i_extent_cache_lock);
134 }
135 
136 void udf_evict_inode(struct inode *inode)
137 {
138 	struct udf_inode_info *iinfo = UDF_I(inode);
139 	int want_delete = 0;
140 
141 	if (!is_bad_inode(inode)) {
142 		if (!inode->i_nlink) {
143 			want_delete = 1;
144 			udf_setsize(inode, 0);
145 			udf_update_inode(inode, IS_SYNC(inode));
146 		}
147 		if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB &&
148 		    inode->i_size != iinfo->i_lenExtents) {
149 			udf_warn(inode->i_sb,
150 				 "Inode %lu (mode %o) has inode size %llu different from extent length %llu. Filesystem need not be standards compliant.\n",
151 				 inode->i_ino, inode->i_mode,
152 				 (unsigned long long)inode->i_size,
153 				 (unsigned long long)iinfo->i_lenExtents);
154 		}
155 	}
156 	truncate_inode_pages_final(&inode->i_data);
157 	invalidate_inode_buffers(inode);
158 	clear_inode(inode);
159 	kfree(iinfo->i_data);
160 	iinfo->i_data = NULL;
161 	udf_clear_extent_cache(inode);
162 	if (want_delete) {
163 		udf_free_inode(inode);
164 	}
165 }
166 
167 static void udf_write_failed(struct address_space *mapping, loff_t to)
168 {
169 	struct inode *inode = mapping->host;
170 	struct udf_inode_info *iinfo = UDF_I(inode);
171 	loff_t isize = inode->i_size;
172 
173 	if (to > isize) {
174 		truncate_pagecache(inode, isize);
175 		if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
176 			down_write(&iinfo->i_data_sem);
177 			udf_clear_extent_cache(inode);
178 			udf_truncate_extents(inode);
179 			up_write(&iinfo->i_data_sem);
180 		}
181 	}
182 }
183 
184 static int udf_adinicb_writepage(struct folio *folio,
185 				 struct writeback_control *wbc, void *data)
186 {
187 	struct inode *inode = folio->mapping->host;
188 	struct udf_inode_info *iinfo = UDF_I(inode);
189 
190 	BUG_ON(!folio_test_locked(folio));
191 	BUG_ON(folio->index != 0);
192 	memcpy_from_file_folio(iinfo->i_data + iinfo->i_lenEAttr, folio, 0,
193 		       i_size_read(inode));
194 	folio_unlock(folio);
195 	mark_inode_dirty(inode);
196 
197 	return 0;
198 }
199 
200 static int udf_writepages(struct address_space *mapping,
201 			  struct writeback_control *wbc)
202 {
203 	struct inode *inode = mapping->host;
204 	struct udf_inode_info *iinfo = UDF_I(inode);
205 
206 	if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB)
207 		return mpage_writepages(mapping, wbc, udf_get_block_wb);
208 	return write_cache_pages(mapping, wbc, udf_adinicb_writepage, NULL);
209 }
210 
211 static void udf_adinicb_readpage(struct page *page)
212 {
213 	struct inode *inode = page->mapping->host;
214 	char *kaddr;
215 	struct udf_inode_info *iinfo = UDF_I(inode);
216 	loff_t isize = i_size_read(inode);
217 
218 	kaddr = kmap_local_page(page);
219 	memcpy(kaddr, iinfo->i_data + iinfo->i_lenEAttr, isize);
220 	memset(kaddr + isize, 0, PAGE_SIZE - isize);
221 	flush_dcache_page(page);
222 	SetPageUptodate(page);
223 	kunmap_local(kaddr);
224 }
225 
226 static int udf_read_folio(struct file *file, struct folio *folio)
227 {
228 	struct udf_inode_info *iinfo = UDF_I(file_inode(file));
229 
230 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
231 		udf_adinicb_readpage(&folio->page);
232 		folio_unlock(folio);
233 		return 0;
234 	}
235 	return mpage_read_folio(folio, udf_get_block);
236 }
237 
238 static void udf_readahead(struct readahead_control *rac)
239 {
240 	struct udf_inode_info *iinfo = UDF_I(rac->mapping->host);
241 
242 	/*
243 	 * No readahead needed for in-ICB files and udf_get_block() would get
244 	 * confused for such file anyway.
245 	 */
246 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
247 		return;
248 
249 	mpage_readahead(rac, udf_get_block);
250 }
251 
252 static int udf_write_begin(struct file *file, struct address_space *mapping,
253 			   loff_t pos, unsigned len,
254 			   struct page **pagep, void **fsdata)
255 {
256 	struct udf_inode_info *iinfo = UDF_I(file_inode(file));
257 	struct page *page;
258 	int ret;
259 
260 	if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
261 		ret = block_write_begin(mapping, pos, len, pagep,
262 					udf_get_block);
263 		if (unlikely(ret))
264 			udf_write_failed(mapping, pos + len);
265 		return ret;
266 	}
267 	if (WARN_ON_ONCE(pos >= PAGE_SIZE))
268 		return -EIO;
269 	page = grab_cache_page_write_begin(mapping, 0);
270 	if (!page)
271 		return -ENOMEM;
272 	*pagep = page;
273 	if (!PageUptodate(page))
274 		udf_adinicb_readpage(page);
275 	return 0;
276 }
277 
278 static int udf_write_end(struct file *file, struct address_space *mapping,
279 			 loff_t pos, unsigned len, unsigned copied,
280 			 struct page *page, void *fsdata)
281 {
282 	struct inode *inode = file_inode(file);
283 	loff_t last_pos;
284 
285 	if (UDF_I(inode)->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB)
286 		return generic_write_end(file, mapping, pos, len, copied, page,
287 					 fsdata);
288 	last_pos = pos + copied;
289 	if (last_pos > inode->i_size)
290 		i_size_write(inode, last_pos);
291 	set_page_dirty(page);
292 	unlock_page(page);
293 	put_page(page);
294 
295 	return copied;
296 }
297 
298 static ssize_t udf_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
299 {
300 	struct file *file = iocb->ki_filp;
301 	struct address_space *mapping = file->f_mapping;
302 	struct inode *inode = mapping->host;
303 	size_t count = iov_iter_count(iter);
304 	ssize_t ret;
305 
306 	/* Fallback to buffered IO for in-ICB files */
307 	if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
308 		return 0;
309 	ret = blockdev_direct_IO(iocb, inode, iter, udf_get_block);
310 	if (unlikely(ret < 0 && iov_iter_rw(iter) == WRITE))
311 		udf_write_failed(mapping, iocb->ki_pos + count);
312 	return ret;
313 }
314 
315 static sector_t udf_bmap(struct address_space *mapping, sector_t block)
316 {
317 	struct udf_inode_info *iinfo = UDF_I(mapping->host);
318 
319 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
320 		return -EINVAL;
321 	return generic_block_bmap(mapping, block, udf_get_block);
322 }
323 
324 const struct address_space_operations udf_aops = {
325 	.dirty_folio	= block_dirty_folio,
326 	.invalidate_folio = block_invalidate_folio,
327 	.read_folio	= udf_read_folio,
328 	.readahead	= udf_readahead,
329 	.writepages	= udf_writepages,
330 	.write_begin	= udf_write_begin,
331 	.write_end	= udf_write_end,
332 	.direct_IO	= udf_direct_IO,
333 	.bmap		= udf_bmap,
334 	.migrate_folio	= buffer_migrate_folio,
335 };
336 
337 /*
338  * Expand file stored in ICB to a normal one-block-file
339  *
340  * This function requires i_mutex held
341  */
342 int udf_expand_file_adinicb(struct inode *inode)
343 {
344 	struct folio *folio;
345 	struct udf_inode_info *iinfo = UDF_I(inode);
346 	int err;
347 
348 	WARN_ON_ONCE(!inode_is_locked(inode));
349 	if (!iinfo->i_lenAlloc) {
350 		down_write(&iinfo->i_data_sem);
351 		if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
352 			iinfo->i_alloc_type = ICBTAG_FLAG_AD_SHORT;
353 		else
354 			iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG;
355 		up_write(&iinfo->i_data_sem);
356 		mark_inode_dirty(inode);
357 		return 0;
358 	}
359 
360 	folio = __filemap_get_folio(inode->i_mapping, 0,
361 			FGP_LOCK | FGP_ACCESSED | FGP_CREAT, GFP_KERNEL);
362 	if (IS_ERR(folio))
363 		return PTR_ERR(folio);
364 
365 	if (!folio_test_uptodate(folio))
366 		udf_adinicb_readpage(&folio->page);
367 	down_write(&iinfo->i_data_sem);
368 	memset(iinfo->i_data + iinfo->i_lenEAttr, 0x00,
369 	       iinfo->i_lenAlloc);
370 	iinfo->i_lenAlloc = 0;
371 	if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
372 		iinfo->i_alloc_type = ICBTAG_FLAG_AD_SHORT;
373 	else
374 		iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG;
375 	folio_mark_dirty(folio);
376 	folio_unlock(folio);
377 	up_write(&iinfo->i_data_sem);
378 	err = filemap_fdatawrite(inode->i_mapping);
379 	if (err) {
380 		/* Restore everything back so that we don't lose data... */
381 		folio_lock(folio);
382 		down_write(&iinfo->i_data_sem);
383 		memcpy_from_folio(iinfo->i_data + iinfo->i_lenEAttr,
384 				folio, 0, inode->i_size);
385 		folio_unlock(folio);
386 		iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB;
387 		iinfo->i_lenAlloc = inode->i_size;
388 		up_write(&iinfo->i_data_sem);
389 	}
390 	folio_put(folio);
391 	mark_inode_dirty(inode);
392 
393 	return err;
394 }
395 
396 #define UDF_MAP_CREATE		0x01	/* Mapping can allocate new blocks */
397 #define UDF_MAP_NOPREALLOC	0x02	/* Do not preallocate blocks */
398 
399 #define UDF_BLK_MAPPED	0x01	/* Block was successfully mapped */
400 #define UDF_BLK_NEW	0x02	/* Block was freshly allocated */
401 
402 struct udf_map_rq {
403 	sector_t lblk;
404 	udf_pblk_t pblk;
405 	int iflags;		/* UDF_MAP_ flags determining behavior */
406 	int oflags;		/* UDF_BLK_ flags reporting results */
407 };
408 
409 static int udf_map_block(struct inode *inode, struct udf_map_rq *map)
410 {
411 	int ret;
412 	struct udf_inode_info *iinfo = UDF_I(inode);
413 
414 	if (WARN_ON_ONCE(iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB))
415 		return -EFSCORRUPTED;
416 
417 	map->oflags = 0;
418 	if (!(map->iflags & UDF_MAP_CREATE)) {
419 		struct kernel_lb_addr eloc;
420 		uint32_t elen;
421 		sector_t offset;
422 		struct extent_position epos = {};
423 		int8_t etype;
424 
425 		down_read(&iinfo->i_data_sem);
426 		ret = inode_bmap(inode, map->lblk, &epos, &eloc, &elen, &offset,
427 				 &etype);
428 		if (ret < 0)
429 			goto out_read;
430 		if (ret > 0 && etype == (EXT_RECORDED_ALLOCATED >> 30)) {
431 			map->pblk = udf_get_lb_pblock(inode->i_sb, &eloc,
432 							offset);
433 			map->oflags |= UDF_BLK_MAPPED;
434 			ret = 0;
435 		}
436 out_read:
437 		up_read(&iinfo->i_data_sem);
438 		brelse(epos.bh);
439 
440 		return ret;
441 	}
442 
443 	down_write(&iinfo->i_data_sem);
444 	/*
445 	 * Block beyond EOF and prealloc extents? Just discard preallocation
446 	 * as it is not useful and complicates things.
447 	 */
448 	if (((loff_t)map->lblk) << inode->i_blkbits >= iinfo->i_lenExtents)
449 		udf_discard_prealloc(inode);
450 	udf_clear_extent_cache(inode);
451 	ret = inode_getblk(inode, map);
452 	up_write(&iinfo->i_data_sem);
453 	return ret;
454 }
455 
456 static int __udf_get_block(struct inode *inode, sector_t block,
457 			   struct buffer_head *bh_result, int flags)
458 {
459 	int err;
460 	struct udf_map_rq map = {
461 		.lblk = block,
462 		.iflags = flags,
463 	};
464 
465 	err = udf_map_block(inode, &map);
466 	if (err < 0)
467 		return err;
468 	if (map.oflags & UDF_BLK_MAPPED) {
469 		map_bh(bh_result, inode->i_sb, map.pblk);
470 		if (map.oflags & UDF_BLK_NEW)
471 			set_buffer_new(bh_result);
472 	}
473 	return 0;
474 }
475 
476 int udf_get_block(struct inode *inode, sector_t block,
477 		  struct buffer_head *bh_result, int create)
478 {
479 	int flags = create ? UDF_MAP_CREATE : 0;
480 
481 	/*
482 	 * We preallocate blocks only for regular files. It also makes sense
483 	 * for directories but there's a problem when to drop the
484 	 * preallocation. We might use some delayed work for that but I feel
485 	 * it's overengineering for a filesystem like UDF.
486 	 */
487 	if (!S_ISREG(inode->i_mode))
488 		flags |= UDF_MAP_NOPREALLOC;
489 	return __udf_get_block(inode, block, bh_result, flags);
490 }
491 
492 /*
493  * We shouldn't be allocating blocks on page writeback since we allocate them
494  * on page fault. We can spot dirty buffers without allocated blocks though
495  * when truncate expands file. These however don't have valid data so we can
496  * safely ignore them. So never allocate blocks from page writeback.
497  */
498 static int udf_get_block_wb(struct inode *inode, sector_t block,
499 			    struct buffer_head *bh_result, int create)
500 {
501 	return __udf_get_block(inode, block, bh_result, 0);
502 }
503 
504 /* Extend the file with new blocks totaling 'new_block_bytes',
505  * return the number of extents added
506  */
507 static int udf_do_extend_file(struct inode *inode,
508 			      struct extent_position *last_pos,
509 			      struct kernel_long_ad *last_ext,
510 			      loff_t new_block_bytes)
511 {
512 	uint32_t add;
513 	int count = 0, fake = !(last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
514 	struct super_block *sb = inode->i_sb;
515 	struct udf_inode_info *iinfo;
516 	int err;
517 
518 	/* The previous extent is fake and we should not extend by anything
519 	 * - there's nothing to do... */
520 	if (!new_block_bytes && fake)
521 		return 0;
522 
523 	iinfo = UDF_I(inode);
524 	/* Round the last extent up to a multiple of block size */
525 	if (last_ext->extLength & (sb->s_blocksize - 1)) {
526 		last_ext->extLength =
527 			(last_ext->extLength & UDF_EXTENT_FLAG_MASK) |
528 			(((last_ext->extLength & UDF_EXTENT_LENGTH_MASK) +
529 			  sb->s_blocksize - 1) & ~(sb->s_blocksize - 1));
530 		iinfo->i_lenExtents =
531 			(iinfo->i_lenExtents + sb->s_blocksize - 1) &
532 			~(sb->s_blocksize - 1);
533 	}
534 
535 	add = 0;
536 	/* Can we merge with the previous extent? */
537 	if ((last_ext->extLength & UDF_EXTENT_FLAG_MASK) ==
538 					EXT_NOT_RECORDED_NOT_ALLOCATED) {
539 		add = (1 << 30) - sb->s_blocksize -
540 			(last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
541 		if (add > new_block_bytes)
542 			add = new_block_bytes;
543 		new_block_bytes -= add;
544 		last_ext->extLength += add;
545 	}
546 
547 	if (fake) {
548 		err = udf_add_aext(inode, last_pos, &last_ext->extLocation,
549 				   last_ext->extLength, 1);
550 		if (err < 0)
551 			goto out_err;
552 		count++;
553 	} else {
554 		struct kernel_lb_addr tmploc;
555 		uint32_t tmplen;
556 		int8_t tmptype;
557 
558 		udf_write_aext(inode, last_pos, &last_ext->extLocation,
559 				last_ext->extLength, 1);
560 
561 		/*
562 		 * We've rewritten the last extent. If we are going to add
563 		 * more extents, we may need to enter possible following
564 		 * empty indirect extent.
565 		 */
566 		if (new_block_bytes) {
567 			err = udf_next_aext(inode, last_pos, &tmploc, &tmplen,
568 					    &tmptype, 0);
569 			if (err < 0)
570 				goto out_err;
571 		}
572 	}
573 	iinfo->i_lenExtents += add;
574 
575 	/* Managed to do everything necessary? */
576 	if (!new_block_bytes)
577 		goto out;
578 
579 	/* All further extents will be NOT_RECORDED_NOT_ALLOCATED */
580 	last_ext->extLocation.logicalBlockNum = 0;
581 	last_ext->extLocation.partitionReferenceNum = 0;
582 	add = (1 << 30) - sb->s_blocksize;
583 	last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED | add;
584 
585 	/* Create enough extents to cover the whole hole */
586 	while (new_block_bytes > add) {
587 		new_block_bytes -= add;
588 		err = udf_add_aext(inode, last_pos, &last_ext->extLocation,
589 				   last_ext->extLength, 1);
590 		if (err)
591 			goto out_err;
592 		iinfo->i_lenExtents += add;
593 		count++;
594 	}
595 	if (new_block_bytes) {
596 		last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
597 			new_block_bytes;
598 		err = udf_add_aext(inode, last_pos, &last_ext->extLocation,
599 				   last_ext->extLength, 1);
600 		if (err)
601 			goto out_err;
602 		iinfo->i_lenExtents += new_block_bytes;
603 		count++;
604 	}
605 
606 out:
607 	/* last_pos should point to the last written extent... */
608 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
609 		last_pos->offset -= sizeof(struct short_ad);
610 	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
611 		last_pos->offset -= sizeof(struct long_ad);
612 	else
613 		return -EIO;
614 
615 	return count;
616 out_err:
617 	/* Remove extents we've created so far */
618 	udf_clear_extent_cache(inode);
619 	udf_truncate_extents(inode);
620 	return err;
621 }
622 
623 /* Extend the final block of the file to final_block_len bytes */
624 static void udf_do_extend_final_block(struct inode *inode,
625 				      struct extent_position *last_pos,
626 				      struct kernel_long_ad *last_ext,
627 				      uint32_t new_elen)
628 {
629 	uint32_t added_bytes;
630 
631 	/*
632 	 * Extent already large enough? It may be already rounded up to block
633 	 * size...
634 	 */
635 	if (new_elen <= (last_ext->extLength & UDF_EXTENT_LENGTH_MASK))
636 		return;
637 	added_bytes = new_elen - (last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
638 	last_ext->extLength += added_bytes;
639 	UDF_I(inode)->i_lenExtents += added_bytes;
640 
641 	udf_write_aext(inode, last_pos, &last_ext->extLocation,
642 			last_ext->extLength, 1);
643 }
644 
645 static int udf_extend_file(struct inode *inode, loff_t newsize)
646 {
647 
648 	struct extent_position epos;
649 	struct kernel_lb_addr eloc;
650 	uint32_t elen;
651 	int8_t etype;
652 	struct super_block *sb = inode->i_sb;
653 	sector_t first_block = newsize >> sb->s_blocksize_bits, offset;
654 	loff_t new_elen;
655 	int adsize;
656 	struct udf_inode_info *iinfo = UDF_I(inode);
657 	struct kernel_long_ad extent;
658 	int err = 0;
659 	bool within_last_ext;
660 
661 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
662 		adsize = sizeof(struct short_ad);
663 	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
664 		adsize = sizeof(struct long_ad);
665 	else
666 		BUG();
667 
668 	down_write(&iinfo->i_data_sem);
669 	/*
670 	 * When creating hole in file, just don't bother with preserving
671 	 * preallocation. It likely won't be very useful anyway.
672 	 */
673 	udf_discard_prealloc(inode);
674 
675 	err = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset, &etype);
676 	if (err < 0)
677 		goto out;
678 	within_last_ext = (err == 1);
679 	/* We don't expect extents past EOF... */
680 	WARN_ON_ONCE(within_last_ext &&
681 		     elen > ((loff_t)offset + 1) << inode->i_blkbits);
682 
683 	if ((!epos.bh && epos.offset == udf_file_entry_alloc_offset(inode)) ||
684 	    (epos.bh && epos.offset == sizeof(struct allocExtDesc))) {
685 		/* File has no extents at all or has empty last
686 		 * indirect extent! Create a fake extent... */
687 		extent.extLocation.logicalBlockNum = 0;
688 		extent.extLocation.partitionReferenceNum = 0;
689 		extent.extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
690 	} else {
691 		epos.offset -= adsize;
692 		err = udf_next_aext(inode, &epos, &extent.extLocation,
693 				    &extent.extLength, &etype, 0);
694 		if (err <= 0)
695 			goto out;
696 		extent.extLength |= etype << 30;
697 	}
698 
699 	new_elen = ((loff_t)offset << inode->i_blkbits) |
700 					(newsize & (sb->s_blocksize - 1));
701 
702 	/* File has extent covering the new size (could happen when extending
703 	 * inside a block)?
704 	 */
705 	if (within_last_ext) {
706 		/* Extending file within the last file block */
707 		udf_do_extend_final_block(inode, &epos, &extent, new_elen);
708 	} else {
709 		err = udf_do_extend_file(inode, &epos, &extent, new_elen);
710 	}
711 
712 	if (err < 0)
713 		goto out;
714 	err = 0;
715 out:
716 	brelse(epos.bh);
717 	up_write(&iinfo->i_data_sem);
718 	return err;
719 }
720 
721 static int inode_getblk(struct inode *inode, struct udf_map_rq *map)
722 {
723 	struct kernel_long_ad laarr[EXTENT_MERGE_SIZE];
724 	struct extent_position prev_epos, cur_epos, next_epos;
725 	int count = 0, startnum = 0, endnum = 0;
726 	uint32_t elen = 0, tmpelen;
727 	struct kernel_lb_addr eloc, tmpeloc;
728 	int c = 1;
729 	loff_t lbcount = 0, b_off = 0;
730 	udf_pblk_t newblocknum;
731 	sector_t offset = 0;
732 	int8_t etype, tmpetype;
733 	struct udf_inode_info *iinfo = UDF_I(inode);
734 	udf_pblk_t goal = 0, pgoal = iinfo->i_location.logicalBlockNum;
735 	int lastblock = 0;
736 	bool isBeyondEOF = false;
737 	int ret = 0;
738 
739 	prev_epos.offset = udf_file_entry_alloc_offset(inode);
740 	prev_epos.block = iinfo->i_location;
741 	prev_epos.bh = NULL;
742 	cur_epos = next_epos = prev_epos;
743 	b_off = (loff_t)map->lblk << inode->i_sb->s_blocksize_bits;
744 
745 	/* find the extent which contains the block we are looking for.
746 	   alternate between laarr[0] and laarr[1] for locations of the
747 	   current extent, and the previous extent */
748 	do {
749 		if (prev_epos.bh != cur_epos.bh) {
750 			brelse(prev_epos.bh);
751 			get_bh(cur_epos.bh);
752 			prev_epos.bh = cur_epos.bh;
753 		}
754 		if (cur_epos.bh != next_epos.bh) {
755 			brelse(cur_epos.bh);
756 			get_bh(next_epos.bh);
757 			cur_epos.bh = next_epos.bh;
758 		}
759 
760 		lbcount += elen;
761 
762 		prev_epos.block = cur_epos.block;
763 		cur_epos.block = next_epos.block;
764 
765 		prev_epos.offset = cur_epos.offset;
766 		cur_epos.offset = next_epos.offset;
767 
768 		ret = udf_next_aext(inode, &next_epos, &eloc, &elen, &etype, 1);
769 		if (ret < 0) {
770 			goto out_free;
771 		} else if (ret == 0) {
772 			isBeyondEOF = true;
773 			break;
774 		}
775 
776 		c = !c;
777 
778 		laarr[c].extLength = (etype << 30) | elen;
779 		laarr[c].extLocation = eloc;
780 
781 		if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
782 			pgoal = eloc.logicalBlockNum +
783 				((elen + inode->i_sb->s_blocksize - 1) >>
784 				 inode->i_sb->s_blocksize_bits);
785 
786 		count++;
787 	} while (lbcount + elen <= b_off);
788 
789 	b_off -= lbcount;
790 	offset = b_off >> inode->i_sb->s_blocksize_bits;
791 	/*
792 	 * Move prev_epos and cur_epos into indirect extent if we are at
793 	 * the pointer to it
794 	 */
795 	ret = udf_next_aext(inode, &prev_epos, &tmpeloc, &tmpelen, &tmpetype, 0);
796 	if (ret < 0)
797 		goto out_free;
798 	ret = udf_next_aext(inode, &cur_epos, &tmpeloc, &tmpelen, &tmpetype, 0);
799 	if (ret < 0)
800 		goto out_free;
801 
802 	/* if the extent is allocated and recorded, return the block
803 	   if the extent is not a multiple of the blocksize, round up */
804 
805 	if (!isBeyondEOF && etype == (EXT_RECORDED_ALLOCATED >> 30)) {
806 		if (elen & (inode->i_sb->s_blocksize - 1)) {
807 			elen = EXT_RECORDED_ALLOCATED |
808 				((elen + inode->i_sb->s_blocksize - 1) &
809 				 ~(inode->i_sb->s_blocksize - 1));
810 			iinfo->i_lenExtents =
811 				ALIGN(iinfo->i_lenExtents,
812 				      inode->i_sb->s_blocksize);
813 			udf_write_aext(inode, &cur_epos, &eloc, elen, 1);
814 		}
815 		map->oflags = UDF_BLK_MAPPED;
816 		map->pblk = udf_get_lb_pblock(inode->i_sb, &eloc, offset);
817 		goto out_free;
818 	}
819 
820 	/* Are we beyond EOF and preallocated extent? */
821 	if (isBeyondEOF) {
822 		loff_t hole_len;
823 
824 		if (count) {
825 			if (c)
826 				laarr[0] = laarr[1];
827 			startnum = 1;
828 		} else {
829 			/* Create a fake extent when there's not one */
830 			memset(&laarr[0].extLocation, 0x00,
831 				sizeof(struct kernel_lb_addr));
832 			laarr[0].extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
833 			/* Will udf_do_extend_file() create real extent from
834 			   a fake one? */
835 			startnum = (offset > 0);
836 		}
837 		/* Create extents for the hole between EOF and offset */
838 		hole_len = (loff_t)offset << inode->i_blkbits;
839 		ret = udf_do_extend_file(inode, &prev_epos, laarr, hole_len);
840 		if (ret < 0)
841 			goto out_free;
842 		c = 0;
843 		offset = 0;
844 		count += ret;
845 		/*
846 		 * Is there any real extent? - otherwise we overwrite the fake
847 		 * one...
848 		 */
849 		if (count)
850 			c = !c;
851 		laarr[c].extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
852 			inode->i_sb->s_blocksize;
853 		memset(&laarr[c].extLocation, 0x00,
854 			sizeof(struct kernel_lb_addr));
855 		count++;
856 		endnum = c + 1;
857 		lastblock = 1;
858 	} else {
859 		endnum = startnum = ((count > 2) ? 2 : count);
860 
861 		/* if the current extent is in position 0,
862 		   swap it with the previous */
863 		if (!c && count != 1) {
864 			laarr[2] = laarr[0];
865 			laarr[0] = laarr[1];
866 			laarr[1] = laarr[2];
867 			c = 1;
868 		}
869 
870 		/* if the current block is located in an extent,
871 		   read the next extent */
872 		ret = udf_next_aext(inode, &next_epos, &eloc, &elen, &etype, 0);
873 		if (ret > 0) {
874 			laarr[c + 1].extLength = (etype << 30) | elen;
875 			laarr[c + 1].extLocation = eloc;
876 			count++;
877 			startnum++;
878 			endnum++;
879 		} else if (ret == 0)
880 			lastblock = 1;
881 		else
882 			goto out_free;
883 	}
884 
885 	/* if the current extent is not recorded but allocated, get the
886 	 * block in the extent corresponding to the requested block */
887 	if ((laarr[c].extLength >> 30) == (EXT_NOT_RECORDED_ALLOCATED >> 30))
888 		newblocknum = laarr[c].extLocation.logicalBlockNum + offset;
889 	else { /* otherwise, allocate a new block */
890 		if (iinfo->i_next_alloc_block == map->lblk)
891 			goal = iinfo->i_next_alloc_goal;
892 
893 		if (!goal) {
894 			if (!(goal = pgoal)) /* XXX: what was intended here? */
895 				goal = iinfo->i_location.logicalBlockNum + 1;
896 		}
897 
898 		newblocknum = udf_new_block(inode->i_sb, inode,
899 				iinfo->i_location.partitionReferenceNum,
900 				goal, &ret);
901 		if (!newblocknum)
902 			goto out_free;
903 		if (isBeyondEOF)
904 			iinfo->i_lenExtents += inode->i_sb->s_blocksize;
905 	}
906 
907 	/* if the extent the requsted block is located in contains multiple
908 	 * blocks, split the extent into at most three extents. blocks prior
909 	 * to requested block, requested block, and blocks after requested
910 	 * block */
911 	udf_split_extents(inode, &c, offset, newblocknum, laarr, &endnum);
912 
913 	if (!(map->iflags & UDF_MAP_NOPREALLOC))
914 		udf_prealloc_extents(inode, c, lastblock, laarr, &endnum);
915 
916 	/* merge any continuous blocks in laarr */
917 	udf_merge_extents(inode, laarr, &endnum);
918 
919 	/* write back the new extents, inserting new extents if the new number
920 	 * of extents is greater than the old number, and deleting extents if
921 	 * the new number of extents is less than the old number */
922 	ret = udf_update_extents(inode, laarr, startnum, endnum, &prev_epos);
923 	if (ret < 0)
924 		goto out_free;
925 
926 	map->pblk = udf_get_pblock(inode->i_sb, newblocknum,
927 				iinfo->i_location.partitionReferenceNum, 0);
928 	if (!map->pblk) {
929 		ret = -EFSCORRUPTED;
930 		goto out_free;
931 	}
932 	map->oflags = UDF_BLK_NEW | UDF_BLK_MAPPED;
933 	iinfo->i_next_alloc_block = map->lblk + 1;
934 	iinfo->i_next_alloc_goal = newblocknum + 1;
935 	inode_set_ctime_current(inode);
936 
937 	if (IS_SYNC(inode))
938 		udf_sync_inode(inode);
939 	else
940 		mark_inode_dirty(inode);
941 	ret = 0;
942 out_free:
943 	brelse(prev_epos.bh);
944 	brelse(cur_epos.bh);
945 	brelse(next_epos.bh);
946 	return ret;
947 }
948 
949 static void udf_split_extents(struct inode *inode, int *c, int offset,
950 			       udf_pblk_t newblocknum,
951 			       struct kernel_long_ad *laarr, int *endnum)
952 {
953 	unsigned long blocksize = inode->i_sb->s_blocksize;
954 	unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
955 
956 	if ((laarr[*c].extLength >> 30) == (EXT_NOT_RECORDED_ALLOCATED >> 30) ||
957 	    (laarr[*c].extLength >> 30) ==
958 				(EXT_NOT_RECORDED_NOT_ALLOCATED >> 30)) {
959 		int curr = *c;
960 		int blen = ((laarr[curr].extLength & UDF_EXTENT_LENGTH_MASK) +
961 			    blocksize - 1) >> blocksize_bits;
962 		int8_t etype = (laarr[curr].extLength >> 30);
963 
964 		if (blen == 1)
965 			;
966 		else if (!offset || blen == offset + 1) {
967 			laarr[curr + 2] = laarr[curr + 1];
968 			laarr[curr + 1] = laarr[curr];
969 		} else {
970 			laarr[curr + 3] = laarr[curr + 1];
971 			laarr[curr + 2] = laarr[curr + 1] = laarr[curr];
972 		}
973 
974 		if (offset) {
975 			if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
976 				udf_free_blocks(inode->i_sb, inode,
977 						&laarr[curr].extLocation,
978 						0, offset);
979 				laarr[curr].extLength =
980 					EXT_NOT_RECORDED_NOT_ALLOCATED |
981 					(offset << blocksize_bits);
982 				laarr[curr].extLocation.logicalBlockNum = 0;
983 				laarr[curr].extLocation.
984 						partitionReferenceNum = 0;
985 			} else
986 				laarr[curr].extLength = (etype << 30) |
987 					(offset << blocksize_bits);
988 			curr++;
989 			(*c)++;
990 			(*endnum)++;
991 		}
992 
993 		laarr[curr].extLocation.logicalBlockNum = newblocknum;
994 		if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
995 			laarr[curr].extLocation.partitionReferenceNum =
996 				UDF_I(inode)->i_location.partitionReferenceNum;
997 		laarr[curr].extLength = EXT_RECORDED_ALLOCATED |
998 			blocksize;
999 		curr++;
1000 
1001 		if (blen != offset + 1) {
1002 			if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
1003 				laarr[curr].extLocation.logicalBlockNum +=
1004 								offset + 1;
1005 			laarr[curr].extLength = (etype << 30) |
1006 				((blen - (offset + 1)) << blocksize_bits);
1007 			curr++;
1008 			(*endnum)++;
1009 		}
1010 	}
1011 }
1012 
1013 static void udf_prealloc_extents(struct inode *inode, int c, int lastblock,
1014 				 struct kernel_long_ad *laarr,
1015 				 int *endnum)
1016 {
1017 	int start, length = 0, currlength = 0, i;
1018 
1019 	if (*endnum >= (c + 1)) {
1020 		if (!lastblock)
1021 			return;
1022 		else
1023 			start = c;
1024 	} else {
1025 		if ((laarr[c + 1].extLength >> 30) ==
1026 					(EXT_NOT_RECORDED_ALLOCATED >> 30)) {
1027 			start = c + 1;
1028 			length = currlength =
1029 				(((laarr[c + 1].extLength &
1030 					UDF_EXTENT_LENGTH_MASK) +
1031 				inode->i_sb->s_blocksize - 1) >>
1032 				inode->i_sb->s_blocksize_bits);
1033 		} else
1034 			start = c;
1035 	}
1036 
1037 	for (i = start + 1; i <= *endnum; i++) {
1038 		if (i == *endnum) {
1039 			if (lastblock)
1040 				length += UDF_DEFAULT_PREALLOC_BLOCKS;
1041 		} else if ((laarr[i].extLength >> 30) ==
1042 				(EXT_NOT_RECORDED_NOT_ALLOCATED >> 30)) {
1043 			length += (((laarr[i].extLength &
1044 						UDF_EXTENT_LENGTH_MASK) +
1045 				    inode->i_sb->s_blocksize - 1) >>
1046 				    inode->i_sb->s_blocksize_bits);
1047 		} else
1048 			break;
1049 	}
1050 
1051 	if (length) {
1052 		int next = laarr[start].extLocation.logicalBlockNum +
1053 			(((laarr[start].extLength & UDF_EXTENT_LENGTH_MASK) +
1054 			  inode->i_sb->s_blocksize - 1) >>
1055 			  inode->i_sb->s_blocksize_bits);
1056 		int numalloc = udf_prealloc_blocks(inode->i_sb, inode,
1057 				laarr[start].extLocation.partitionReferenceNum,
1058 				next, (UDF_DEFAULT_PREALLOC_BLOCKS > length ?
1059 				length : UDF_DEFAULT_PREALLOC_BLOCKS) -
1060 				currlength);
1061 		if (numalloc) 	{
1062 			if (start == (c + 1))
1063 				laarr[start].extLength +=
1064 					(numalloc <<
1065 					 inode->i_sb->s_blocksize_bits);
1066 			else {
1067 				memmove(&laarr[c + 2], &laarr[c + 1],
1068 					sizeof(struct long_ad) * (*endnum - (c + 1)));
1069 				(*endnum)++;
1070 				laarr[c + 1].extLocation.logicalBlockNum = next;
1071 				laarr[c + 1].extLocation.partitionReferenceNum =
1072 					laarr[c].extLocation.
1073 							partitionReferenceNum;
1074 				laarr[c + 1].extLength =
1075 					EXT_NOT_RECORDED_ALLOCATED |
1076 					(numalloc <<
1077 					 inode->i_sb->s_blocksize_bits);
1078 				start = c + 1;
1079 			}
1080 
1081 			for (i = start + 1; numalloc && i < *endnum; i++) {
1082 				int elen = ((laarr[i].extLength &
1083 						UDF_EXTENT_LENGTH_MASK) +
1084 					    inode->i_sb->s_blocksize - 1) >>
1085 					    inode->i_sb->s_blocksize_bits;
1086 
1087 				if (elen > numalloc) {
1088 					laarr[i].extLength -=
1089 						(numalloc <<
1090 						 inode->i_sb->s_blocksize_bits);
1091 					numalloc = 0;
1092 				} else {
1093 					numalloc -= elen;
1094 					if (*endnum > (i + 1))
1095 						memmove(&laarr[i],
1096 							&laarr[i + 1],
1097 							sizeof(struct long_ad) *
1098 							(*endnum - (i + 1)));
1099 					i--;
1100 					(*endnum)--;
1101 				}
1102 			}
1103 			UDF_I(inode)->i_lenExtents +=
1104 				numalloc << inode->i_sb->s_blocksize_bits;
1105 		}
1106 	}
1107 }
1108 
1109 static void udf_merge_extents(struct inode *inode, struct kernel_long_ad *laarr,
1110 			      int *endnum)
1111 {
1112 	int i;
1113 	unsigned long blocksize = inode->i_sb->s_blocksize;
1114 	unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
1115 
1116 	for (i = 0; i < (*endnum - 1); i++) {
1117 		struct kernel_long_ad *li /*l[i]*/ = &laarr[i];
1118 		struct kernel_long_ad *lip1 /*l[i plus 1]*/ = &laarr[i + 1];
1119 
1120 		if (((li->extLength >> 30) == (lip1->extLength >> 30)) &&
1121 			(((li->extLength >> 30) ==
1122 				(EXT_NOT_RECORDED_NOT_ALLOCATED >> 30)) ||
1123 			((lip1->extLocation.logicalBlockNum -
1124 			  li->extLocation.logicalBlockNum) ==
1125 			(((li->extLength & UDF_EXTENT_LENGTH_MASK) +
1126 			blocksize - 1) >> blocksize_bits)))) {
1127 
1128 			if (((li->extLength & UDF_EXTENT_LENGTH_MASK) +
1129 			     (lip1->extLength & UDF_EXTENT_LENGTH_MASK) +
1130 			     blocksize - 1) <= UDF_EXTENT_LENGTH_MASK) {
1131 				li->extLength = lip1->extLength +
1132 					(((li->extLength &
1133 						UDF_EXTENT_LENGTH_MASK) +
1134 					 blocksize - 1) & ~(blocksize - 1));
1135 				if (*endnum > (i + 2))
1136 					memmove(&laarr[i + 1], &laarr[i + 2],
1137 						sizeof(struct long_ad) *
1138 						(*endnum - (i + 2)));
1139 				i--;
1140 				(*endnum)--;
1141 			}
1142 		} else if (((li->extLength >> 30) ==
1143 				(EXT_NOT_RECORDED_ALLOCATED >> 30)) &&
1144 			   ((lip1->extLength >> 30) ==
1145 				(EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))) {
1146 			udf_free_blocks(inode->i_sb, inode, &li->extLocation, 0,
1147 					((li->extLength &
1148 					  UDF_EXTENT_LENGTH_MASK) +
1149 					 blocksize - 1) >> blocksize_bits);
1150 			li->extLocation.logicalBlockNum = 0;
1151 			li->extLocation.partitionReferenceNum = 0;
1152 
1153 			if (((li->extLength & UDF_EXTENT_LENGTH_MASK) +
1154 			     (lip1->extLength & UDF_EXTENT_LENGTH_MASK) +
1155 			     blocksize - 1) & ~UDF_EXTENT_LENGTH_MASK) {
1156 				lip1->extLength = (lip1->extLength -
1157 						   (li->extLength &
1158 						   UDF_EXTENT_LENGTH_MASK) +
1159 						   UDF_EXTENT_LENGTH_MASK) &
1160 						   ~(blocksize - 1);
1161 				li->extLength = (li->extLength &
1162 						 UDF_EXTENT_FLAG_MASK) +
1163 						(UDF_EXTENT_LENGTH_MASK + 1) -
1164 						blocksize;
1165 			} else {
1166 				li->extLength = lip1->extLength +
1167 					(((li->extLength &
1168 						UDF_EXTENT_LENGTH_MASK) +
1169 					  blocksize - 1) & ~(blocksize - 1));
1170 				if (*endnum > (i + 2))
1171 					memmove(&laarr[i + 1], &laarr[i + 2],
1172 						sizeof(struct long_ad) *
1173 						(*endnum - (i + 2)));
1174 				i--;
1175 				(*endnum)--;
1176 			}
1177 		} else if ((li->extLength >> 30) ==
1178 					(EXT_NOT_RECORDED_ALLOCATED >> 30)) {
1179 			udf_free_blocks(inode->i_sb, inode,
1180 					&li->extLocation, 0,
1181 					((li->extLength &
1182 						UDF_EXTENT_LENGTH_MASK) +
1183 					 blocksize - 1) >> blocksize_bits);
1184 			li->extLocation.logicalBlockNum = 0;
1185 			li->extLocation.partitionReferenceNum = 0;
1186 			li->extLength = (li->extLength &
1187 						UDF_EXTENT_LENGTH_MASK) |
1188 						EXT_NOT_RECORDED_NOT_ALLOCATED;
1189 		}
1190 	}
1191 }
1192 
1193 static int udf_update_extents(struct inode *inode, struct kernel_long_ad *laarr,
1194 			      int startnum, int endnum,
1195 			      struct extent_position *epos)
1196 {
1197 	int start = 0, i;
1198 	struct kernel_lb_addr tmploc;
1199 	uint32_t tmplen;
1200 	int8_t tmpetype;
1201 	int err;
1202 
1203 	if (startnum > endnum) {
1204 		for (i = 0; i < (startnum - endnum); i++)
1205 			udf_delete_aext(inode, *epos);
1206 	} else if (startnum < endnum) {
1207 		for (i = 0; i < (endnum - startnum); i++) {
1208 			err = udf_insert_aext(inode, *epos,
1209 					      laarr[i].extLocation,
1210 					      laarr[i].extLength);
1211 			/*
1212 			 * If we fail here, we are likely corrupting the extent
1213 			 * list and leaking blocks. At least stop early to
1214 			 * limit the damage.
1215 			 */
1216 			if (err < 0)
1217 				return err;
1218 			err = udf_next_aext(inode, epos, &laarr[i].extLocation,
1219 				      &laarr[i].extLength, &tmpetype, 1);
1220 			if (err < 0)
1221 				return err;
1222 			start++;
1223 		}
1224 	}
1225 
1226 	for (i = start; i < endnum; i++) {
1227 		err = udf_next_aext(inode, epos, &tmploc, &tmplen, &tmpetype, 0);
1228 		if (err < 0)
1229 			return err;
1230 
1231 		udf_write_aext(inode, epos, &laarr[i].extLocation,
1232 			       laarr[i].extLength, 1);
1233 	}
1234 	return 0;
1235 }
1236 
1237 struct buffer_head *udf_bread(struct inode *inode, udf_pblk_t block,
1238 			      int create, int *err)
1239 {
1240 	struct buffer_head *bh = NULL;
1241 	struct udf_map_rq map = {
1242 		.lblk = block,
1243 		.iflags = UDF_MAP_NOPREALLOC | (create ? UDF_MAP_CREATE : 0),
1244 	};
1245 
1246 	*err = udf_map_block(inode, &map);
1247 	if (*err || !(map.oflags & UDF_BLK_MAPPED))
1248 		return NULL;
1249 
1250 	bh = sb_getblk(inode->i_sb, map.pblk);
1251 	if (!bh) {
1252 		*err = -ENOMEM;
1253 		return NULL;
1254 	}
1255 	if (map.oflags & UDF_BLK_NEW) {
1256 		lock_buffer(bh);
1257 		memset(bh->b_data, 0x00, inode->i_sb->s_blocksize);
1258 		set_buffer_uptodate(bh);
1259 		unlock_buffer(bh);
1260 		mark_buffer_dirty_inode(bh, inode);
1261 		return bh;
1262 	}
1263 
1264 	if (bh_read(bh, 0) >= 0)
1265 		return bh;
1266 
1267 	brelse(bh);
1268 	*err = -EIO;
1269 	return NULL;
1270 }
1271 
1272 int udf_setsize(struct inode *inode, loff_t newsize)
1273 {
1274 	int err = 0;
1275 	struct udf_inode_info *iinfo;
1276 	unsigned int bsize = i_blocksize(inode);
1277 
1278 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1279 	      S_ISLNK(inode->i_mode)))
1280 		return -EINVAL;
1281 	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1282 		return -EPERM;
1283 
1284 	iinfo = UDF_I(inode);
1285 	if (newsize > inode->i_size) {
1286 		if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
1287 			if (bsize >=
1288 			    (udf_file_entry_alloc_offset(inode) + newsize)) {
1289 				down_write(&iinfo->i_data_sem);
1290 				iinfo->i_lenAlloc = newsize;
1291 				up_write(&iinfo->i_data_sem);
1292 				goto set_size;
1293 			}
1294 			err = udf_expand_file_adinicb(inode);
1295 			if (err)
1296 				return err;
1297 		}
1298 		err = udf_extend_file(inode, newsize);
1299 		if (err)
1300 			return err;
1301 set_size:
1302 		truncate_setsize(inode, newsize);
1303 	} else {
1304 		if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
1305 			down_write(&iinfo->i_data_sem);
1306 			udf_clear_extent_cache(inode);
1307 			memset(iinfo->i_data + iinfo->i_lenEAttr + newsize,
1308 			       0x00, bsize - newsize -
1309 			       udf_file_entry_alloc_offset(inode));
1310 			iinfo->i_lenAlloc = newsize;
1311 			truncate_setsize(inode, newsize);
1312 			up_write(&iinfo->i_data_sem);
1313 			goto update_time;
1314 		}
1315 		err = block_truncate_page(inode->i_mapping, newsize,
1316 					  udf_get_block);
1317 		if (err)
1318 			return err;
1319 		truncate_setsize(inode, newsize);
1320 		down_write(&iinfo->i_data_sem);
1321 		udf_clear_extent_cache(inode);
1322 		err = udf_truncate_extents(inode);
1323 		up_write(&iinfo->i_data_sem);
1324 		if (err)
1325 			return err;
1326 	}
1327 update_time:
1328 	inode->i_mtime = inode_set_ctime_current(inode);
1329 	if (IS_SYNC(inode))
1330 		udf_sync_inode(inode);
1331 	else
1332 		mark_inode_dirty(inode);
1333 	return err;
1334 }
1335 
1336 /*
1337  * Maximum length of linked list formed by ICB hierarchy. The chosen number is
1338  * arbitrary - just that we hopefully don't limit any real use of rewritten
1339  * inode on write-once media but avoid looping for too long on corrupted media.
1340  */
1341 #define UDF_MAX_ICB_NESTING 1024
1342 
1343 static int udf_read_inode(struct inode *inode, bool hidden_inode)
1344 {
1345 	struct buffer_head *bh = NULL;
1346 	struct fileEntry *fe;
1347 	struct extendedFileEntry *efe;
1348 	uint16_t ident;
1349 	struct udf_inode_info *iinfo = UDF_I(inode);
1350 	struct udf_sb_info *sbi = UDF_SB(inode->i_sb);
1351 	struct kernel_lb_addr *iloc = &iinfo->i_location;
1352 	unsigned int link_count;
1353 	unsigned int indirections = 0;
1354 	int bs = inode->i_sb->s_blocksize;
1355 	int ret = -EIO;
1356 	uint32_t uid, gid;
1357 	struct timespec64 ctime;
1358 
1359 reread:
1360 	if (iloc->partitionReferenceNum >= sbi->s_partitions) {
1361 		udf_debug("partition reference: %u > logical volume partitions: %u\n",
1362 			  iloc->partitionReferenceNum, sbi->s_partitions);
1363 		return -EIO;
1364 	}
1365 
1366 	if (iloc->logicalBlockNum >=
1367 	    sbi->s_partmaps[iloc->partitionReferenceNum].s_partition_len) {
1368 		udf_debug("block=%u, partition=%u out of range\n",
1369 			  iloc->logicalBlockNum, iloc->partitionReferenceNum);
1370 		return -EIO;
1371 	}
1372 
1373 	/*
1374 	 * Set defaults, but the inode is still incomplete!
1375 	 * Note: get_new_inode() sets the following on a new inode:
1376 	 *      i_sb = sb
1377 	 *      i_no = ino
1378 	 *      i_flags = sb->s_flags
1379 	 *      i_state = 0
1380 	 * clean_inode(): zero fills and sets
1381 	 *      i_count = 1
1382 	 *      i_nlink = 1
1383 	 *      i_op = NULL;
1384 	 */
1385 	bh = udf_read_ptagged(inode->i_sb, iloc, 0, &ident);
1386 	if (!bh) {
1387 		udf_err(inode->i_sb, "(ino %lu) failed !bh\n", inode->i_ino);
1388 		return -EIO;
1389 	}
1390 
1391 	if (ident != TAG_IDENT_FE && ident != TAG_IDENT_EFE &&
1392 	    ident != TAG_IDENT_USE) {
1393 		udf_err(inode->i_sb, "(ino %lu) failed ident=%u\n",
1394 			inode->i_ino, ident);
1395 		goto out;
1396 	}
1397 
1398 	fe = (struct fileEntry *)bh->b_data;
1399 	efe = (struct extendedFileEntry *)bh->b_data;
1400 
1401 	if (fe->icbTag.strategyType == cpu_to_le16(4096)) {
1402 		struct buffer_head *ibh;
1403 
1404 		ibh = udf_read_ptagged(inode->i_sb, iloc, 1, &ident);
1405 		if (ident == TAG_IDENT_IE && ibh) {
1406 			struct kernel_lb_addr loc;
1407 			struct indirectEntry *ie;
1408 
1409 			ie = (struct indirectEntry *)ibh->b_data;
1410 			loc = lelb_to_cpu(ie->indirectICB.extLocation);
1411 
1412 			if (ie->indirectICB.extLength) {
1413 				brelse(ibh);
1414 				memcpy(&iinfo->i_location, &loc,
1415 				       sizeof(struct kernel_lb_addr));
1416 				if (++indirections > UDF_MAX_ICB_NESTING) {
1417 					udf_err(inode->i_sb,
1418 						"too many ICBs in ICB hierarchy"
1419 						" (max %d supported)\n",
1420 						UDF_MAX_ICB_NESTING);
1421 					goto out;
1422 				}
1423 				brelse(bh);
1424 				goto reread;
1425 			}
1426 		}
1427 		brelse(ibh);
1428 	} else if (fe->icbTag.strategyType != cpu_to_le16(4)) {
1429 		udf_err(inode->i_sb, "unsupported strategy type: %u\n",
1430 			le16_to_cpu(fe->icbTag.strategyType));
1431 		goto out;
1432 	}
1433 	if (fe->icbTag.strategyType == cpu_to_le16(4))
1434 		iinfo->i_strat4096 = 0;
1435 	else /* if (fe->icbTag.strategyType == cpu_to_le16(4096)) */
1436 		iinfo->i_strat4096 = 1;
1437 
1438 	iinfo->i_alloc_type = le16_to_cpu(fe->icbTag.flags) &
1439 							ICBTAG_FLAG_AD_MASK;
1440 	if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_SHORT &&
1441 	    iinfo->i_alloc_type != ICBTAG_FLAG_AD_LONG &&
1442 	    iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
1443 		ret = -EIO;
1444 		goto out;
1445 	}
1446 	iinfo->i_hidden = hidden_inode;
1447 	iinfo->i_unique = 0;
1448 	iinfo->i_lenEAttr = 0;
1449 	iinfo->i_lenExtents = 0;
1450 	iinfo->i_lenAlloc = 0;
1451 	iinfo->i_next_alloc_block = 0;
1452 	iinfo->i_next_alloc_goal = 0;
1453 	if (fe->descTag.tagIdent == cpu_to_le16(TAG_IDENT_EFE)) {
1454 		iinfo->i_efe = 1;
1455 		iinfo->i_use = 0;
1456 		ret = udf_alloc_i_data(inode, bs -
1457 					sizeof(struct extendedFileEntry));
1458 		if (ret)
1459 			goto out;
1460 		memcpy(iinfo->i_data,
1461 		       bh->b_data + sizeof(struct extendedFileEntry),
1462 		       bs - sizeof(struct extendedFileEntry));
1463 	} else if (fe->descTag.tagIdent == cpu_to_le16(TAG_IDENT_FE)) {
1464 		iinfo->i_efe = 0;
1465 		iinfo->i_use = 0;
1466 		ret = udf_alloc_i_data(inode, bs - sizeof(struct fileEntry));
1467 		if (ret)
1468 			goto out;
1469 		memcpy(iinfo->i_data,
1470 		       bh->b_data + sizeof(struct fileEntry),
1471 		       bs - sizeof(struct fileEntry));
1472 	} else if (fe->descTag.tagIdent == cpu_to_le16(TAG_IDENT_USE)) {
1473 		iinfo->i_efe = 0;
1474 		iinfo->i_use = 1;
1475 		iinfo->i_lenAlloc = le32_to_cpu(
1476 				((struct unallocSpaceEntry *)bh->b_data)->
1477 				 lengthAllocDescs);
1478 		ret = udf_alloc_i_data(inode, bs -
1479 					sizeof(struct unallocSpaceEntry));
1480 		if (ret)
1481 			goto out;
1482 		memcpy(iinfo->i_data,
1483 		       bh->b_data + sizeof(struct unallocSpaceEntry),
1484 		       bs - sizeof(struct unallocSpaceEntry));
1485 		return 0;
1486 	}
1487 
1488 	ret = -EIO;
1489 	read_lock(&sbi->s_cred_lock);
1490 	uid = le32_to_cpu(fe->uid);
1491 	if (uid == UDF_INVALID_ID ||
1492 	    UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_UID_SET))
1493 		inode->i_uid = sbi->s_uid;
1494 	else
1495 		i_uid_write(inode, uid);
1496 
1497 	gid = le32_to_cpu(fe->gid);
1498 	if (gid == UDF_INVALID_ID ||
1499 	    UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_GID_SET))
1500 		inode->i_gid = sbi->s_gid;
1501 	else
1502 		i_gid_write(inode, gid);
1503 
1504 	if (fe->icbTag.fileType != ICBTAG_FILE_TYPE_DIRECTORY &&
1505 			sbi->s_fmode != UDF_INVALID_MODE)
1506 		inode->i_mode = sbi->s_fmode;
1507 	else if (fe->icbTag.fileType == ICBTAG_FILE_TYPE_DIRECTORY &&
1508 			sbi->s_dmode != UDF_INVALID_MODE)
1509 		inode->i_mode = sbi->s_dmode;
1510 	else
1511 		inode->i_mode = udf_convert_permissions(fe);
1512 	inode->i_mode &= ~sbi->s_umask;
1513 	iinfo->i_extraPerms = le32_to_cpu(fe->permissions) & ~FE_MAPPED_PERMS;
1514 
1515 	read_unlock(&sbi->s_cred_lock);
1516 
1517 	link_count = le16_to_cpu(fe->fileLinkCount);
1518 	if (!link_count) {
1519 		if (!hidden_inode) {
1520 			ret = -ESTALE;
1521 			goto out;
1522 		}
1523 		link_count = 1;
1524 	}
1525 	set_nlink(inode, link_count);
1526 
1527 	inode->i_size = le64_to_cpu(fe->informationLength);
1528 	iinfo->i_lenExtents = inode->i_size;
1529 
1530 	if (iinfo->i_efe == 0) {
1531 		inode->i_blocks = le64_to_cpu(fe->logicalBlocksRecorded) <<
1532 			(inode->i_sb->s_blocksize_bits - 9);
1533 
1534 		udf_disk_stamp_to_time(&inode->i_atime, fe->accessTime);
1535 		udf_disk_stamp_to_time(&inode->i_mtime, fe->modificationTime);
1536 		udf_disk_stamp_to_time(&ctime, fe->attrTime);
1537 		inode_set_ctime_to_ts(inode, ctime);
1538 
1539 		iinfo->i_unique = le64_to_cpu(fe->uniqueID);
1540 		iinfo->i_lenEAttr = le32_to_cpu(fe->lengthExtendedAttr);
1541 		iinfo->i_lenAlloc = le32_to_cpu(fe->lengthAllocDescs);
1542 		iinfo->i_checkpoint = le32_to_cpu(fe->checkpoint);
1543 		iinfo->i_streamdir = 0;
1544 		iinfo->i_lenStreams = 0;
1545 	} else {
1546 		inode->i_blocks = le64_to_cpu(efe->logicalBlocksRecorded) <<
1547 		    (inode->i_sb->s_blocksize_bits - 9);
1548 
1549 		udf_disk_stamp_to_time(&inode->i_atime, efe->accessTime);
1550 		udf_disk_stamp_to_time(&inode->i_mtime, efe->modificationTime);
1551 		udf_disk_stamp_to_time(&iinfo->i_crtime, efe->createTime);
1552 		udf_disk_stamp_to_time(&ctime, efe->attrTime);
1553 		inode_set_ctime_to_ts(inode, ctime);
1554 
1555 		iinfo->i_unique = le64_to_cpu(efe->uniqueID);
1556 		iinfo->i_lenEAttr = le32_to_cpu(efe->lengthExtendedAttr);
1557 		iinfo->i_lenAlloc = le32_to_cpu(efe->lengthAllocDescs);
1558 		iinfo->i_checkpoint = le32_to_cpu(efe->checkpoint);
1559 
1560 		/* Named streams */
1561 		iinfo->i_streamdir = (efe->streamDirectoryICB.extLength != 0);
1562 		iinfo->i_locStreamdir =
1563 			lelb_to_cpu(efe->streamDirectoryICB.extLocation);
1564 		iinfo->i_lenStreams = le64_to_cpu(efe->objectSize);
1565 		if (iinfo->i_lenStreams >= inode->i_size)
1566 			iinfo->i_lenStreams -= inode->i_size;
1567 		else
1568 			iinfo->i_lenStreams = 0;
1569 	}
1570 	inode->i_generation = iinfo->i_unique;
1571 
1572 	/*
1573 	 * Sanity check length of allocation descriptors and extended attrs to
1574 	 * avoid integer overflows
1575 	 */
1576 	if (iinfo->i_lenEAttr > bs || iinfo->i_lenAlloc > bs)
1577 		goto out;
1578 	/* Now do exact checks */
1579 	if (udf_file_entry_alloc_offset(inode) + iinfo->i_lenAlloc > bs)
1580 		goto out;
1581 	/* Sanity checks for files in ICB so that we don't get confused later */
1582 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
1583 		/*
1584 		 * For file in ICB data is stored in allocation descriptor
1585 		 * so sizes should match
1586 		 */
1587 		if (iinfo->i_lenAlloc != inode->i_size)
1588 			goto out;
1589 		/* File in ICB has to fit in there... */
1590 		if (inode->i_size > bs - udf_file_entry_alloc_offset(inode))
1591 			goto out;
1592 	}
1593 
1594 	switch (fe->icbTag.fileType) {
1595 	case ICBTAG_FILE_TYPE_DIRECTORY:
1596 		inode->i_op = &udf_dir_inode_operations;
1597 		inode->i_fop = &udf_dir_operations;
1598 		inode->i_mode |= S_IFDIR;
1599 		inc_nlink(inode);
1600 		break;
1601 	case ICBTAG_FILE_TYPE_REALTIME:
1602 	case ICBTAG_FILE_TYPE_REGULAR:
1603 	case ICBTAG_FILE_TYPE_UNDEF:
1604 	case ICBTAG_FILE_TYPE_VAT20:
1605 		inode->i_data.a_ops = &udf_aops;
1606 		inode->i_op = &udf_file_inode_operations;
1607 		inode->i_fop = &udf_file_operations;
1608 		inode->i_mode |= S_IFREG;
1609 		break;
1610 	case ICBTAG_FILE_TYPE_BLOCK:
1611 		inode->i_mode |= S_IFBLK;
1612 		break;
1613 	case ICBTAG_FILE_TYPE_CHAR:
1614 		inode->i_mode |= S_IFCHR;
1615 		break;
1616 	case ICBTAG_FILE_TYPE_FIFO:
1617 		init_special_inode(inode, inode->i_mode | S_IFIFO, 0);
1618 		break;
1619 	case ICBTAG_FILE_TYPE_SOCKET:
1620 		init_special_inode(inode, inode->i_mode | S_IFSOCK, 0);
1621 		break;
1622 	case ICBTAG_FILE_TYPE_SYMLINK:
1623 		inode->i_data.a_ops = &udf_symlink_aops;
1624 		inode->i_op = &udf_symlink_inode_operations;
1625 		inode_nohighmem(inode);
1626 		inode->i_mode = S_IFLNK | 0777;
1627 		break;
1628 	case ICBTAG_FILE_TYPE_MAIN:
1629 		udf_debug("METADATA FILE-----\n");
1630 		break;
1631 	case ICBTAG_FILE_TYPE_MIRROR:
1632 		udf_debug("METADATA MIRROR FILE-----\n");
1633 		break;
1634 	case ICBTAG_FILE_TYPE_BITMAP:
1635 		udf_debug("METADATA BITMAP FILE-----\n");
1636 		break;
1637 	default:
1638 		udf_err(inode->i_sb, "(ino %lu) failed unknown file type=%u\n",
1639 			inode->i_ino, fe->icbTag.fileType);
1640 		goto out;
1641 	}
1642 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1643 		struct deviceSpec *dsea =
1644 			(struct deviceSpec *)udf_get_extendedattr(inode, 12, 1);
1645 		if (dsea) {
1646 			init_special_inode(inode, inode->i_mode,
1647 				MKDEV(le32_to_cpu(dsea->majorDeviceIdent),
1648 				      le32_to_cpu(dsea->minorDeviceIdent)));
1649 			/* Developer ID ??? */
1650 		} else
1651 			goto out;
1652 	}
1653 	ret = 0;
1654 out:
1655 	brelse(bh);
1656 	return ret;
1657 }
1658 
1659 static int udf_alloc_i_data(struct inode *inode, size_t size)
1660 {
1661 	struct udf_inode_info *iinfo = UDF_I(inode);
1662 	iinfo->i_data = kmalloc(size, GFP_KERNEL);
1663 	if (!iinfo->i_data)
1664 		return -ENOMEM;
1665 	return 0;
1666 }
1667 
1668 static umode_t udf_convert_permissions(struct fileEntry *fe)
1669 {
1670 	umode_t mode;
1671 	uint32_t permissions;
1672 	uint32_t flags;
1673 
1674 	permissions = le32_to_cpu(fe->permissions);
1675 	flags = le16_to_cpu(fe->icbTag.flags);
1676 
1677 	mode =	((permissions) & 0007) |
1678 		((permissions >> 2) & 0070) |
1679 		((permissions >> 4) & 0700) |
1680 		((flags & ICBTAG_FLAG_SETUID) ? S_ISUID : 0) |
1681 		((flags & ICBTAG_FLAG_SETGID) ? S_ISGID : 0) |
1682 		((flags & ICBTAG_FLAG_STICKY) ? S_ISVTX : 0);
1683 
1684 	return mode;
1685 }
1686 
1687 void udf_update_extra_perms(struct inode *inode, umode_t mode)
1688 {
1689 	struct udf_inode_info *iinfo = UDF_I(inode);
1690 
1691 	/*
1692 	 * UDF 2.01 sec. 3.3.3.3 Note 2:
1693 	 * In Unix, delete permission tracks write
1694 	 */
1695 	iinfo->i_extraPerms &= ~FE_DELETE_PERMS;
1696 	if (mode & 0200)
1697 		iinfo->i_extraPerms |= FE_PERM_U_DELETE;
1698 	if (mode & 0020)
1699 		iinfo->i_extraPerms |= FE_PERM_G_DELETE;
1700 	if (mode & 0002)
1701 		iinfo->i_extraPerms |= FE_PERM_O_DELETE;
1702 }
1703 
1704 int udf_write_inode(struct inode *inode, struct writeback_control *wbc)
1705 {
1706 	return udf_update_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
1707 }
1708 
1709 static int udf_sync_inode(struct inode *inode)
1710 {
1711 	return udf_update_inode(inode, 1);
1712 }
1713 
1714 static void udf_adjust_time(struct udf_inode_info *iinfo, struct timespec64 time)
1715 {
1716 	if (iinfo->i_crtime.tv_sec > time.tv_sec ||
1717 	    (iinfo->i_crtime.tv_sec == time.tv_sec &&
1718 	     iinfo->i_crtime.tv_nsec > time.tv_nsec))
1719 		iinfo->i_crtime = time;
1720 }
1721 
1722 static int udf_update_inode(struct inode *inode, int do_sync)
1723 {
1724 	struct buffer_head *bh = NULL;
1725 	struct fileEntry *fe;
1726 	struct extendedFileEntry *efe;
1727 	uint64_t lb_recorded;
1728 	uint32_t udfperms;
1729 	uint16_t icbflags;
1730 	uint16_t crclen;
1731 	int err = 0;
1732 	struct udf_sb_info *sbi = UDF_SB(inode->i_sb);
1733 	unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
1734 	struct udf_inode_info *iinfo = UDF_I(inode);
1735 
1736 	bh = sb_getblk(inode->i_sb,
1737 			udf_get_lb_pblock(inode->i_sb, &iinfo->i_location, 0));
1738 	if (!bh) {
1739 		udf_debug("getblk failure\n");
1740 		return -EIO;
1741 	}
1742 
1743 	lock_buffer(bh);
1744 	memset(bh->b_data, 0, inode->i_sb->s_blocksize);
1745 	fe = (struct fileEntry *)bh->b_data;
1746 	efe = (struct extendedFileEntry *)bh->b_data;
1747 
1748 	if (iinfo->i_use) {
1749 		struct unallocSpaceEntry *use =
1750 			(struct unallocSpaceEntry *)bh->b_data;
1751 
1752 		use->lengthAllocDescs = cpu_to_le32(iinfo->i_lenAlloc);
1753 		memcpy(bh->b_data + sizeof(struct unallocSpaceEntry),
1754 		       iinfo->i_data, inode->i_sb->s_blocksize -
1755 					sizeof(struct unallocSpaceEntry));
1756 		use->descTag.tagIdent = cpu_to_le16(TAG_IDENT_USE);
1757 		crclen = sizeof(struct unallocSpaceEntry);
1758 
1759 		goto finish;
1760 	}
1761 
1762 	if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_UID_FORGET))
1763 		fe->uid = cpu_to_le32(UDF_INVALID_ID);
1764 	else
1765 		fe->uid = cpu_to_le32(i_uid_read(inode));
1766 
1767 	if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_GID_FORGET))
1768 		fe->gid = cpu_to_le32(UDF_INVALID_ID);
1769 	else
1770 		fe->gid = cpu_to_le32(i_gid_read(inode));
1771 
1772 	udfperms = ((inode->i_mode & 0007)) |
1773 		   ((inode->i_mode & 0070) << 2) |
1774 		   ((inode->i_mode & 0700) << 4);
1775 
1776 	udfperms |= iinfo->i_extraPerms;
1777 	fe->permissions = cpu_to_le32(udfperms);
1778 
1779 	if (S_ISDIR(inode->i_mode) && inode->i_nlink > 0)
1780 		fe->fileLinkCount = cpu_to_le16(inode->i_nlink - 1);
1781 	else {
1782 		if (iinfo->i_hidden)
1783 			fe->fileLinkCount = cpu_to_le16(0);
1784 		else
1785 			fe->fileLinkCount = cpu_to_le16(inode->i_nlink);
1786 	}
1787 
1788 	fe->informationLength = cpu_to_le64(inode->i_size);
1789 
1790 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1791 		struct regid *eid;
1792 		struct deviceSpec *dsea =
1793 			(struct deviceSpec *)udf_get_extendedattr(inode, 12, 1);
1794 		if (!dsea) {
1795 			dsea = (struct deviceSpec *)
1796 				udf_add_extendedattr(inode,
1797 						     sizeof(struct deviceSpec) +
1798 						     sizeof(struct regid), 12, 0x3);
1799 			dsea->attrType = cpu_to_le32(12);
1800 			dsea->attrSubtype = 1;
1801 			dsea->attrLength = cpu_to_le32(
1802 						sizeof(struct deviceSpec) +
1803 						sizeof(struct regid));
1804 			dsea->impUseLength = cpu_to_le32(sizeof(struct regid));
1805 		}
1806 		eid = (struct regid *)dsea->impUse;
1807 		memset(eid, 0, sizeof(*eid));
1808 		strcpy(eid->ident, UDF_ID_DEVELOPER);
1809 		eid->identSuffix[0] = UDF_OS_CLASS_UNIX;
1810 		eid->identSuffix[1] = UDF_OS_ID_LINUX;
1811 		dsea->majorDeviceIdent = cpu_to_le32(imajor(inode));
1812 		dsea->minorDeviceIdent = cpu_to_le32(iminor(inode));
1813 	}
1814 
1815 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
1816 		lb_recorded = 0; /* No extents => no blocks! */
1817 	else
1818 		lb_recorded =
1819 			(inode->i_blocks + (1 << (blocksize_bits - 9)) - 1) >>
1820 			(blocksize_bits - 9);
1821 
1822 	if (iinfo->i_efe == 0) {
1823 		memcpy(bh->b_data + sizeof(struct fileEntry),
1824 		       iinfo->i_data,
1825 		       inode->i_sb->s_blocksize - sizeof(struct fileEntry));
1826 		fe->logicalBlocksRecorded = cpu_to_le64(lb_recorded);
1827 
1828 		udf_time_to_disk_stamp(&fe->accessTime, inode->i_atime);
1829 		udf_time_to_disk_stamp(&fe->modificationTime, inode->i_mtime);
1830 		udf_time_to_disk_stamp(&fe->attrTime, inode_get_ctime(inode));
1831 		memset(&(fe->impIdent), 0, sizeof(struct regid));
1832 		strcpy(fe->impIdent.ident, UDF_ID_DEVELOPER);
1833 		fe->impIdent.identSuffix[0] = UDF_OS_CLASS_UNIX;
1834 		fe->impIdent.identSuffix[1] = UDF_OS_ID_LINUX;
1835 		fe->uniqueID = cpu_to_le64(iinfo->i_unique);
1836 		fe->lengthExtendedAttr = cpu_to_le32(iinfo->i_lenEAttr);
1837 		fe->lengthAllocDescs = cpu_to_le32(iinfo->i_lenAlloc);
1838 		fe->checkpoint = cpu_to_le32(iinfo->i_checkpoint);
1839 		fe->descTag.tagIdent = cpu_to_le16(TAG_IDENT_FE);
1840 		crclen = sizeof(struct fileEntry);
1841 	} else {
1842 		memcpy(bh->b_data + sizeof(struct extendedFileEntry),
1843 		       iinfo->i_data,
1844 		       inode->i_sb->s_blocksize -
1845 					sizeof(struct extendedFileEntry));
1846 		efe->objectSize =
1847 			cpu_to_le64(inode->i_size + iinfo->i_lenStreams);
1848 		efe->logicalBlocksRecorded = cpu_to_le64(lb_recorded);
1849 
1850 		if (iinfo->i_streamdir) {
1851 			struct long_ad *icb_lad = &efe->streamDirectoryICB;
1852 
1853 			icb_lad->extLocation =
1854 				cpu_to_lelb(iinfo->i_locStreamdir);
1855 			icb_lad->extLength =
1856 				cpu_to_le32(inode->i_sb->s_blocksize);
1857 		}
1858 
1859 		udf_adjust_time(iinfo, inode->i_atime);
1860 		udf_adjust_time(iinfo, inode->i_mtime);
1861 		udf_adjust_time(iinfo, inode_get_ctime(inode));
1862 
1863 		udf_time_to_disk_stamp(&efe->accessTime, inode->i_atime);
1864 		udf_time_to_disk_stamp(&efe->modificationTime, inode->i_mtime);
1865 		udf_time_to_disk_stamp(&efe->createTime, iinfo->i_crtime);
1866 		udf_time_to_disk_stamp(&efe->attrTime, inode_get_ctime(inode));
1867 
1868 		memset(&(efe->impIdent), 0, sizeof(efe->impIdent));
1869 		strcpy(efe->impIdent.ident, UDF_ID_DEVELOPER);
1870 		efe->impIdent.identSuffix[0] = UDF_OS_CLASS_UNIX;
1871 		efe->impIdent.identSuffix[1] = UDF_OS_ID_LINUX;
1872 		efe->uniqueID = cpu_to_le64(iinfo->i_unique);
1873 		efe->lengthExtendedAttr = cpu_to_le32(iinfo->i_lenEAttr);
1874 		efe->lengthAllocDescs = cpu_to_le32(iinfo->i_lenAlloc);
1875 		efe->checkpoint = cpu_to_le32(iinfo->i_checkpoint);
1876 		efe->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EFE);
1877 		crclen = sizeof(struct extendedFileEntry);
1878 	}
1879 
1880 finish:
1881 	if (iinfo->i_strat4096) {
1882 		fe->icbTag.strategyType = cpu_to_le16(4096);
1883 		fe->icbTag.strategyParameter = cpu_to_le16(1);
1884 		fe->icbTag.numEntries = cpu_to_le16(2);
1885 	} else {
1886 		fe->icbTag.strategyType = cpu_to_le16(4);
1887 		fe->icbTag.numEntries = cpu_to_le16(1);
1888 	}
1889 
1890 	if (iinfo->i_use)
1891 		fe->icbTag.fileType = ICBTAG_FILE_TYPE_USE;
1892 	else if (S_ISDIR(inode->i_mode))
1893 		fe->icbTag.fileType = ICBTAG_FILE_TYPE_DIRECTORY;
1894 	else if (S_ISREG(inode->i_mode))
1895 		fe->icbTag.fileType = ICBTAG_FILE_TYPE_REGULAR;
1896 	else if (S_ISLNK(inode->i_mode))
1897 		fe->icbTag.fileType = ICBTAG_FILE_TYPE_SYMLINK;
1898 	else if (S_ISBLK(inode->i_mode))
1899 		fe->icbTag.fileType = ICBTAG_FILE_TYPE_BLOCK;
1900 	else if (S_ISCHR(inode->i_mode))
1901 		fe->icbTag.fileType = ICBTAG_FILE_TYPE_CHAR;
1902 	else if (S_ISFIFO(inode->i_mode))
1903 		fe->icbTag.fileType = ICBTAG_FILE_TYPE_FIFO;
1904 	else if (S_ISSOCK(inode->i_mode))
1905 		fe->icbTag.fileType = ICBTAG_FILE_TYPE_SOCKET;
1906 
1907 	icbflags =	iinfo->i_alloc_type |
1908 			((inode->i_mode & S_ISUID) ? ICBTAG_FLAG_SETUID : 0) |
1909 			((inode->i_mode & S_ISGID) ? ICBTAG_FLAG_SETGID : 0) |
1910 			((inode->i_mode & S_ISVTX) ? ICBTAG_FLAG_STICKY : 0) |
1911 			(le16_to_cpu(fe->icbTag.flags) &
1912 				~(ICBTAG_FLAG_AD_MASK | ICBTAG_FLAG_SETUID |
1913 				ICBTAG_FLAG_SETGID | ICBTAG_FLAG_STICKY));
1914 
1915 	fe->icbTag.flags = cpu_to_le16(icbflags);
1916 	if (sbi->s_udfrev >= 0x0200)
1917 		fe->descTag.descVersion = cpu_to_le16(3);
1918 	else
1919 		fe->descTag.descVersion = cpu_to_le16(2);
1920 	fe->descTag.tagSerialNum = cpu_to_le16(sbi->s_serial_number);
1921 	fe->descTag.tagLocation = cpu_to_le32(
1922 					iinfo->i_location.logicalBlockNum);
1923 	crclen += iinfo->i_lenEAttr + iinfo->i_lenAlloc - sizeof(struct tag);
1924 	fe->descTag.descCRCLength = cpu_to_le16(crclen);
1925 	fe->descTag.descCRC = cpu_to_le16(crc_itu_t(0, (char *)fe + sizeof(struct tag),
1926 						  crclen));
1927 	fe->descTag.tagChecksum = udf_tag_checksum(&fe->descTag);
1928 
1929 	set_buffer_uptodate(bh);
1930 	unlock_buffer(bh);
1931 
1932 	/* write the data blocks */
1933 	mark_buffer_dirty(bh);
1934 	if (do_sync) {
1935 		sync_dirty_buffer(bh);
1936 		if (buffer_write_io_error(bh)) {
1937 			udf_warn(inode->i_sb, "IO error syncing udf inode [%08lx]\n",
1938 				 inode->i_ino);
1939 			err = -EIO;
1940 		}
1941 	}
1942 	brelse(bh);
1943 
1944 	return err;
1945 }
1946 
1947 struct inode *__udf_iget(struct super_block *sb, struct kernel_lb_addr *ino,
1948 			 bool hidden_inode)
1949 {
1950 	unsigned long block = udf_get_lb_pblock(sb, ino, 0);
1951 	struct inode *inode = iget_locked(sb, block);
1952 	int err;
1953 
1954 	if (!inode)
1955 		return ERR_PTR(-ENOMEM);
1956 
1957 	if (!(inode->i_state & I_NEW)) {
1958 		if (UDF_I(inode)->i_hidden != hidden_inode) {
1959 			iput(inode);
1960 			return ERR_PTR(-EFSCORRUPTED);
1961 		}
1962 		return inode;
1963 	}
1964 
1965 	memcpy(&UDF_I(inode)->i_location, ino, sizeof(struct kernel_lb_addr));
1966 	err = udf_read_inode(inode, hidden_inode);
1967 	if (err < 0) {
1968 		iget_failed(inode);
1969 		return ERR_PTR(err);
1970 	}
1971 	unlock_new_inode(inode);
1972 
1973 	return inode;
1974 }
1975 
1976 int udf_setup_indirect_aext(struct inode *inode, udf_pblk_t block,
1977 			    struct extent_position *epos)
1978 {
1979 	struct super_block *sb = inode->i_sb;
1980 	struct buffer_head *bh;
1981 	struct allocExtDesc *aed;
1982 	struct extent_position nepos;
1983 	struct kernel_lb_addr neloc;
1984 	int ver, adsize;
1985 	int err = 0;
1986 
1987 	if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
1988 		adsize = sizeof(struct short_ad);
1989 	else if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_LONG)
1990 		adsize = sizeof(struct long_ad);
1991 	else
1992 		return -EIO;
1993 
1994 	neloc.logicalBlockNum = block;
1995 	neloc.partitionReferenceNum = epos->block.partitionReferenceNum;
1996 
1997 	bh = sb_getblk(sb, udf_get_lb_pblock(sb, &neloc, 0));
1998 	if (!bh)
1999 		return -EIO;
2000 	lock_buffer(bh);
2001 	memset(bh->b_data, 0x00, sb->s_blocksize);
2002 	set_buffer_uptodate(bh);
2003 	unlock_buffer(bh);
2004 	mark_buffer_dirty_inode(bh, inode);
2005 
2006 	aed = (struct allocExtDesc *)(bh->b_data);
2007 	if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT)) {
2008 		aed->previousAllocExtLocation =
2009 				cpu_to_le32(epos->block.logicalBlockNum);
2010 	}
2011 	aed->lengthAllocDescs = cpu_to_le32(0);
2012 	if (UDF_SB(sb)->s_udfrev >= 0x0200)
2013 		ver = 3;
2014 	else
2015 		ver = 2;
2016 	udf_new_tag(bh->b_data, TAG_IDENT_AED, ver, 1, block,
2017 		    sizeof(struct tag));
2018 
2019 	nepos.block = neloc;
2020 	nepos.offset = sizeof(struct allocExtDesc);
2021 	nepos.bh = bh;
2022 
2023 	/*
2024 	 * Do we have to copy current last extent to make space for indirect
2025 	 * one?
2026 	 */
2027 	if (epos->offset + adsize > sb->s_blocksize) {
2028 		struct kernel_lb_addr cp_loc;
2029 		uint32_t cp_len;
2030 		int8_t cp_type;
2031 
2032 		epos->offset -= adsize;
2033 		err = udf_current_aext(inode, epos, &cp_loc, &cp_len, &cp_type, 0);
2034 		if (err <= 0)
2035 			goto err_out;
2036 		cp_len |= ((uint32_t)cp_type) << 30;
2037 
2038 		__udf_add_aext(inode, &nepos, &cp_loc, cp_len, 1);
2039 		udf_write_aext(inode, epos, &nepos.block,
2040 			       sb->s_blocksize | EXT_NEXT_EXTENT_ALLOCDESCS, 0);
2041 	} else {
2042 		__udf_add_aext(inode, epos, &nepos.block,
2043 			       sb->s_blocksize | EXT_NEXT_EXTENT_ALLOCDESCS, 0);
2044 	}
2045 
2046 	brelse(epos->bh);
2047 	*epos = nepos;
2048 
2049 	return 0;
2050 err_out:
2051 	brelse(bh);
2052 	return err;
2053 }
2054 
2055 /*
2056  * Append extent at the given position - should be the first free one in inode
2057  * / indirect extent. This function assumes there is enough space in the inode
2058  * or indirect extent. Use udf_add_aext() if you didn't check for this before.
2059  */
2060 int __udf_add_aext(struct inode *inode, struct extent_position *epos,
2061 		   struct kernel_lb_addr *eloc, uint32_t elen, int inc)
2062 {
2063 	struct udf_inode_info *iinfo = UDF_I(inode);
2064 	struct allocExtDesc *aed;
2065 	int adsize;
2066 
2067 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
2068 		adsize = sizeof(struct short_ad);
2069 	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
2070 		adsize = sizeof(struct long_ad);
2071 	else
2072 		return -EIO;
2073 
2074 	if (!epos->bh) {
2075 		WARN_ON(iinfo->i_lenAlloc !=
2076 			epos->offset - udf_file_entry_alloc_offset(inode));
2077 	} else {
2078 		aed = (struct allocExtDesc *)epos->bh->b_data;
2079 		WARN_ON(le32_to_cpu(aed->lengthAllocDescs) !=
2080 			epos->offset - sizeof(struct allocExtDesc));
2081 		WARN_ON(epos->offset + adsize > inode->i_sb->s_blocksize);
2082 	}
2083 
2084 	udf_write_aext(inode, epos, eloc, elen, inc);
2085 
2086 	if (!epos->bh) {
2087 		iinfo->i_lenAlloc += adsize;
2088 		mark_inode_dirty(inode);
2089 	} else {
2090 		aed = (struct allocExtDesc *)epos->bh->b_data;
2091 		le32_add_cpu(&aed->lengthAllocDescs, adsize);
2092 		if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
2093 				UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
2094 			udf_update_tag(epos->bh->b_data,
2095 					epos->offset + (inc ? 0 : adsize));
2096 		else
2097 			udf_update_tag(epos->bh->b_data,
2098 					sizeof(struct allocExtDesc));
2099 		mark_buffer_dirty_inode(epos->bh, inode);
2100 	}
2101 
2102 	return 0;
2103 }
2104 
2105 /*
2106  * Append extent at given position - should be the first free one in inode
2107  * / indirect extent. Takes care of allocating and linking indirect blocks.
2108  */
2109 int udf_add_aext(struct inode *inode, struct extent_position *epos,
2110 		 struct kernel_lb_addr *eloc, uint32_t elen, int inc)
2111 {
2112 	int adsize;
2113 	struct super_block *sb = inode->i_sb;
2114 
2115 	if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
2116 		adsize = sizeof(struct short_ad);
2117 	else if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_LONG)
2118 		adsize = sizeof(struct long_ad);
2119 	else
2120 		return -EIO;
2121 
2122 	if (epos->offset + (2 * adsize) > sb->s_blocksize) {
2123 		int err;
2124 		udf_pblk_t new_block;
2125 
2126 		new_block = udf_new_block(sb, NULL,
2127 					  epos->block.partitionReferenceNum,
2128 					  epos->block.logicalBlockNum, &err);
2129 		if (!new_block)
2130 			return -ENOSPC;
2131 
2132 		err = udf_setup_indirect_aext(inode, new_block, epos);
2133 		if (err)
2134 			return err;
2135 	}
2136 
2137 	return __udf_add_aext(inode, epos, eloc, elen, inc);
2138 }
2139 
2140 void udf_write_aext(struct inode *inode, struct extent_position *epos,
2141 		    struct kernel_lb_addr *eloc, uint32_t elen, int inc)
2142 {
2143 	int adsize;
2144 	uint8_t *ptr;
2145 	struct short_ad *sad;
2146 	struct long_ad *lad;
2147 	struct udf_inode_info *iinfo = UDF_I(inode);
2148 
2149 	if (!epos->bh)
2150 		ptr = iinfo->i_data + epos->offset -
2151 			udf_file_entry_alloc_offset(inode) +
2152 			iinfo->i_lenEAttr;
2153 	else
2154 		ptr = epos->bh->b_data + epos->offset;
2155 
2156 	switch (iinfo->i_alloc_type) {
2157 	case ICBTAG_FLAG_AD_SHORT:
2158 		sad = (struct short_ad *)ptr;
2159 		sad->extLength = cpu_to_le32(elen);
2160 		sad->extPosition = cpu_to_le32(eloc->logicalBlockNum);
2161 		adsize = sizeof(struct short_ad);
2162 		break;
2163 	case ICBTAG_FLAG_AD_LONG:
2164 		lad = (struct long_ad *)ptr;
2165 		lad->extLength = cpu_to_le32(elen);
2166 		lad->extLocation = cpu_to_lelb(*eloc);
2167 		memset(lad->impUse, 0x00, sizeof(lad->impUse));
2168 		adsize = sizeof(struct long_ad);
2169 		break;
2170 	default:
2171 		return;
2172 	}
2173 
2174 	if (epos->bh) {
2175 		if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
2176 		    UDF_SB(inode->i_sb)->s_udfrev >= 0x0201) {
2177 			struct allocExtDesc *aed =
2178 				(struct allocExtDesc *)epos->bh->b_data;
2179 			udf_update_tag(epos->bh->b_data,
2180 				       le32_to_cpu(aed->lengthAllocDescs) +
2181 				       sizeof(struct allocExtDesc));
2182 		}
2183 		mark_buffer_dirty_inode(epos->bh, inode);
2184 	} else {
2185 		mark_inode_dirty(inode);
2186 	}
2187 
2188 	if (inc)
2189 		epos->offset += adsize;
2190 }
2191 
2192 /*
2193  * Only 1 indirect extent in a row really makes sense but allow upto 16 in case
2194  * someone does some weird stuff.
2195  */
2196 #define UDF_MAX_INDIR_EXTS 16
2197 
2198 /*
2199  * Returns 1 on success, -errno on error, 0 on hit EOF.
2200  */
2201 int udf_next_aext(struct inode *inode, struct extent_position *epos,
2202 		  struct kernel_lb_addr *eloc, uint32_t *elen, int8_t *etype,
2203 		  int inc)
2204 {
2205 	unsigned int indirections = 0;
2206 	int ret = 0;
2207 	udf_pblk_t block;
2208 
2209 	while (1) {
2210 		ret = udf_current_aext(inode, epos, eloc, elen,
2211 				       etype, inc);
2212 		if (ret <= 0)
2213 			return ret;
2214 		if (*etype != (EXT_NEXT_EXTENT_ALLOCDESCS >> 30))
2215 			return ret;
2216 
2217 		if (++indirections > UDF_MAX_INDIR_EXTS) {
2218 			udf_err(inode->i_sb,
2219 				"too many indirect extents in inode %lu\n",
2220 				inode->i_ino);
2221 			return -EFSCORRUPTED;
2222 		}
2223 
2224 		epos->block = *eloc;
2225 		epos->offset = sizeof(struct allocExtDesc);
2226 		brelse(epos->bh);
2227 		block = udf_get_lb_pblock(inode->i_sb, &epos->block, 0);
2228 		epos->bh = sb_bread(inode->i_sb, block);
2229 		if (!epos->bh) {
2230 			udf_debug("reading block %u failed!\n", block);
2231 			return -EIO;
2232 		}
2233 	}
2234 }
2235 
2236 /*
2237  * Returns 1 on success, -errno on error, 0 on hit EOF.
2238  */
2239 int udf_current_aext(struct inode *inode, struct extent_position *epos,
2240 		     struct kernel_lb_addr *eloc, uint32_t *elen, int8_t *etype,
2241 		     int inc)
2242 {
2243 	int alen;
2244 	uint8_t *ptr;
2245 	struct short_ad *sad;
2246 	struct long_ad *lad;
2247 	struct udf_inode_info *iinfo = UDF_I(inode);
2248 
2249 	if (!epos->bh) {
2250 		if (!epos->offset)
2251 			epos->offset = udf_file_entry_alloc_offset(inode);
2252 		ptr = iinfo->i_data + epos->offset -
2253 			udf_file_entry_alloc_offset(inode) +
2254 			iinfo->i_lenEAttr;
2255 		alen = udf_file_entry_alloc_offset(inode) +
2256 							iinfo->i_lenAlloc;
2257 	} else {
2258 		struct allocExtDesc *header =
2259 			(struct allocExtDesc *)epos->bh->b_data;
2260 
2261 		if (!epos->offset)
2262 			epos->offset = sizeof(struct allocExtDesc);
2263 		ptr = epos->bh->b_data + epos->offset;
2264 		if (check_add_overflow(sizeof(struct allocExtDesc),
2265 				le32_to_cpu(header->lengthAllocDescs), &alen))
2266 			return -1;
2267 	}
2268 
2269 	switch (iinfo->i_alloc_type) {
2270 	case ICBTAG_FLAG_AD_SHORT:
2271 		sad = udf_get_fileshortad(ptr, alen, &epos->offset, inc);
2272 		if (!sad)
2273 			return 0;
2274 		*etype = le32_to_cpu(sad->extLength) >> 30;
2275 		eloc->logicalBlockNum = le32_to_cpu(sad->extPosition);
2276 		eloc->partitionReferenceNum =
2277 				iinfo->i_location.partitionReferenceNum;
2278 		*elen = le32_to_cpu(sad->extLength) & UDF_EXTENT_LENGTH_MASK;
2279 		break;
2280 	case ICBTAG_FLAG_AD_LONG:
2281 		lad = udf_get_filelongad(ptr, alen, &epos->offset, inc);
2282 		if (!lad)
2283 			return 0;
2284 		*etype = le32_to_cpu(lad->extLength) >> 30;
2285 		*eloc = lelb_to_cpu(lad->extLocation);
2286 		*elen = le32_to_cpu(lad->extLength) & UDF_EXTENT_LENGTH_MASK;
2287 		break;
2288 	default:
2289 		udf_debug("alloc_type = %u unsupported\n", iinfo->i_alloc_type);
2290 		return -EINVAL;
2291 	}
2292 
2293 	return 1;
2294 }
2295 
2296 static int udf_insert_aext(struct inode *inode, struct extent_position epos,
2297 			   struct kernel_lb_addr neloc, uint32_t nelen)
2298 {
2299 	struct kernel_lb_addr oeloc;
2300 	uint32_t oelen;
2301 	int8_t etype;
2302 	int ret;
2303 
2304 	if (epos.bh)
2305 		get_bh(epos.bh);
2306 
2307 	while (1) {
2308 		ret = udf_next_aext(inode, &epos, &oeloc, &oelen, &etype, 0);
2309 		if (ret <= 0)
2310 			break;
2311 		udf_write_aext(inode, &epos, &neloc, nelen, 1);
2312 		neloc = oeloc;
2313 		nelen = (etype << 30) | oelen;
2314 	}
2315 	if (ret == 0)
2316 		ret = udf_add_aext(inode, &epos, &neloc, nelen, 1);
2317 	brelse(epos.bh);
2318 
2319 	return ret;
2320 }
2321 
2322 int8_t udf_delete_aext(struct inode *inode, struct extent_position epos)
2323 {
2324 	struct extent_position oepos;
2325 	int adsize;
2326 	int8_t etype;
2327 	struct allocExtDesc *aed;
2328 	struct udf_inode_info *iinfo;
2329 	struct kernel_lb_addr eloc;
2330 	uint32_t elen;
2331 	int ret;
2332 
2333 	if (epos.bh) {
2334 		get_bh(epos.bh);
2335 		get_bh(epos.bh);
2336 	}
2337 
2338 	iinfo = UDF_I(inode);
2339 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
2340 		adsize = sizeof(struct short_ad);
2341 	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
2342 		adsize = sizeof(struct long_ad);
2343 	else
2344 		adsize = 0;
2345 
2346 	oepos = epos;
2347 	if (udf_next_aext(inode, &epos, &eloc, &elen, &etype, 1) <= 0)
2348 		return -1;
2349 
2350 	while (1) {
2351 		ret = udf_next_aext(inode, &epos, &eloc, &elen, &etype, 1);
2352 		if (ret < 0) {
2353 			brelse(epos.bh);
2354 			brelse(oepos.bh);
2355 			return -1;
2356 		}
2357 		if (ret == 0)
2358 			break;
2359 		udf_write_aext(inode, &oepos, &eloc, (etype << 30) | elen, 1);
2360 		if (oepos.bh != epos.bh) {
2361 			oepos.block = epos.block;
2362 			brelse(oepos.bh);
2363 			get_bh(epos.bh);
2364 			oepos.bh = epos.bh;
2365 			oepos.offset = epos.offset - adsize;
2366 		}
2367 	}
2368 	memset(&eloc, 0x00, sizeof(struct kernel_lb_addr));
2369 	elen = 0;
2370 
2371 	if (epos.bh != oepos.bh) {
2372 		udf_free_blocks(inode->i_sb, inode, &epos.block, 0, 1);
2373 		udf_write_aext(inode, &oepos, &eloc, elen, 1);
2374 		udf_write_aext(inode, &oepos, &eloc, elen, 1);
2375 		if (!oepos.bh) {
2376 			iinfo->i_lenAlloc -= (adsize * 2);
2377 			mark_inode_dirty(inode);
2378 		} else {
2379 			aed = (struct allocExtDesc *)oepos.bh->b_data;
2380 			le32_add_cpu(&aed->lengthAllocDescs, -(2 * adsize));
2381 			if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
2382 			    UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
2383 				udf_update_tag(oepos.bh->b_data,
2384 						oepos.offset - (2 * adsize));
2385 			else
2386 				udf_update_tag(oepos.bh->b_data,
2387 						sizeof(struct allocExtDesc));
2388 			mark_buffer_dirty_inode(oepos.bh, inode);
2389 		}
2390 	} else {
2391 		udf_write_aext(inode, &oepos, &eloc, elen, 1);
2392 		if (!oepos.bh) {
2393 			iinfo->i_lenAlloc -= adsize;
2394 			mark_inode_dirty(inode);
2395 		} else {
2396 			aed = (struct allocExtDesc *)oepos.bh->b_data;
2397 			le32_add_cpu(&aed->lengthAllocDescs, -adsize);
2398 			if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
2399 			    UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
2400 				udf_update_tag(oepos.bh->b_data,
2401 						epos.offset - adsize);
2402 			else
2403 				udf_update_tag(oepos.bh->b_data,
2404 						sizeof(struct allocExtDesc));
2405 			mark_buffer_dirty_inode(oepos.bh, inode);
2406 		}
2407 	}
2408 
2409 	brelse(epos.bh);
2410 	brelse(oepos.bh);
2411 
2412 	return (elen >> 30);
2413 }
2414 
2415 /*
2416  * Returns 1 on success, -errno on error, 0 on hit EOF.
2417  */
2418 int inode_bmap(struct inode *inode, sector_t block, struct extent_position *pos,
2419 	       struct kernel_lb_addr *eloc, uint32_t *elen, sector_t *offset,
2420 	       int8_t *etype)
2421 {
2422 	unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
2423 	loff_t lbcount = 0, bcount = (loff_t) block << blocksize_bits;
2424 	struct udf_inode_info *iinfo;
2425 	int err = 0;
2426 
2427 	iinfo = UDF_I(inode);
2428 	if (!udf_read_extent_cache(inode, bcount, &lbcount, pos)) {
2429 		pos->offset = 0;
2430 		pos->block = iinfo->i_location;
2431 		pos->bh = NULL;
2432 	}
2433 	*elen = 0;
2434 	do {
2435 		err = udf_next_aext(inode, pos, eloc, elen, etype, 1);
2436 		if (err <= 0) {
2437 			if (err == 0) {
2438 				*offset = (bcount - lbcount) >> blocksize_bits;
2439 				iinfo->i_lenExtents = lbcount;
2440 			}
2441 			return err;
2442 		}
2443 		lbcount += *elen;
2444 	} while (lbcount <= bcount);
2445 	/* update extent cache */
2446 	udf_update_extent_cache(inode, lbcount - *elen, pos);
2447 	*offset = (bcount + *elen - lbcount) >> blocksize_bits;
2448 
2449 	return 1;
2450 }
2451