1 /*
2  *  Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3  */
4 
5 /*
6  *  Written by Anatoly P. Pinchuk pap@namesys.botik.ru
7  *  Programm System Institute
8  *  Pereslavl-Zalessky Russia
9  */
10 
11 #include <linux/time.h>
12 #include <linux/string.h>
13 #include <linux/pagemap.h>
14 #include <linux/bio.h>
15 #include "reiserfs.h"
16 #include <linux/buffer_head.h>
17 #include <linux/quotaops.h>
18 
19 /* Does the buffer contain a disk block which is in the tree. */
B_IS_IN_TREE(const struct buffer_head * bh)20 inline int B_IS_IN_TREE(const struct buffer_head *bh)
21 {
22 
23 	RFALSE(B_LEVEL(bh) > MAX_HEIGHT,
24 	       "PAP-1010: block (%b) has too big level (%z)", bh, bh);
25 
26 	return (B_LEVEL(bh) != FREE_LEVEL);
27 }
28 
29 /* to get item head in le form */
copy_item_head(struct item_head * to,const struct item_head * from)30 inline void copy_item_head(struct item_head *to,
31 			   const struct item_head *from)
32 {
33 	memcpy(to, from, IH_SIZE);
34 }
35 
36 /*
37  * k1 is pointer to on-disk structure which is stored in little-endian
38  * form. k2 is pointer to cpu variable. For key of items of the same
39  * object this returns 0.
40  * Returns: -1 if key1 < key2
41  * 0 if key1 == key2
42  * 1 if key1 > key2
43  */
comp_short_keys(const struct reiserfs_key * le_key,const struct cpu_key * cpu_key)44 inline int comp_short_keys(const struct reiserfs_key *le_key,
45 			   const struct cpu_key *cpu_key)
46 {
47 	__u32 n;
48 	n = le32_to_cpu(le_key->k_dir_id);
49 	if (n < cpu_key->on_disk_key.k_dir_id)
50 		return -1;
51 	if (n > cpu_key->on_disk_key.k_dir_id)
52 		return 1;
53 	n = le32_to_cpu(le_key->k_objectid);
54 	if (n < cpu_key->on_disk_key.k_objectid)
55 		return -1;
56 	if (n > cpu_key->on_disk_key.k_objectid)
57 		return 1;
58 	return 0;
59 }
60 
61 /*
62  * k1 is pointer to on-disk structure which is stored in little-endian
63  * form. k2 is pointer to cpu variable.
64  * Compare keys using all 4 key fields.
65  * Returns: -1 if key1 < key2 0
66  * if key1 = key2 1 if key1 > key2
67  */
comp_keys(const struct reiserfs_key * le_key,const struct cpu_key * cpu_key)68 static inline int comp_keys(const struct reiserfs_key *le_key,
69 			    const struct cpu_key *cpu_key)
70 {
71 	int retval;
72 
73 	retval = comp_short_keys(le_key, cpu_key);
74 	if (retval)
75 		return retval;
76 	if (le_key_k_offset(le_key_version(le_key), le_key) <
77 	    cpu_key_k_offset(cpu_key))
78 		return -1;
79 	if (le_key_k_offset(le_key_version(le_key), le_key) >
80 	    cpu_key_k_offset(cpu_key))
81 		return 1;
82 
83 	if (cpu_key->key_length == 3)
84 		return 0;
85 
86 	/* this part is needed only when tail conversion is in progress */
87 	if (le_key_k_type(le_key_version(le_key), le_key) <
88 	    cpu_key_k_type(cpu_key))
89 		return -1;
90 
91 	if (le_key_k_type(le_key_version(le_key), le_key) >
92 	    cpu_key_k_type(cpu_key))
93 		return 1;
94 
95 	return 0;
96 }
97 
comp_short_le_keys(const struct reiserfs_key * key1,const struct reiserfs_key * key2)98 inline int comp_short_le_keys(const struct reiserfs_key *key1,
99 			      const struct reiserfs_key *key2)
100 {
101 	__u32 *k1_u32, *k2_u32;
102 	int key_length = REISERFS_SHORT_KEY_LEN;
103 
104 	k1_u32 = (__u32 *) key1;
105 	k2_u32 = (__u32 *) key2;
106 	for (; key_length--; ++k1_u32, ++k2_u32) {
107 		if (le32_to_cpu(*k1_u32) < le32_to_cpu(*k2_u32))
108 			return -1;
109 		if (le32_to_cpu(*k1_u32) > le32_to_cpu(*k2_u32))
110 			return 1;
111 	}
112 	return 0;
113 }
114 
le_key2cpu_key(struct cpu_key * to,const struct reiserfs_key * from)115 inline void le_key2cpu_key(struct cpu_key *to, const struct reiserfs_key *from)
116 {
117 	int version;
118 	to->on_disk_key.k_dir_id = le32_to_cpu(from->k_dir_id);
119 	to->on_disk_key.k_objectid = le32_to_cpu(from->k_objectid);
120 
121 	/* find out version of the key */
122 	version = le_key_version(from);
123 	to->version = version;
124 	to->on_disk_key.k_offset = le_key_k_offset(version, from);
125 	to->on_disk_key.k_type = le_key_k_type(version, from);
126 }
127 
128 /*
129  * this does not say which one is bigger, it only returns 1 if keys
130  * are not equal, 0 otherwise
131  */
comp_le_keys(const struct reiserfs_key * k1,const struct reiserfs_key * k2)132 inline int comp_le_keys(const struct reiserfs_key *k1,
133 			const struct reiserfs_key *k2)
134 {
135 	return memcmp(k1, k2, sizeof(struct reiserfs_key));
136 }
137 
138 /**************************************************************************
139  *  Binary search toolkit function                                        *
140  *  Search for an item in the array by the item key                       *
141  *  Returns:    1 if found,  0 if not found;                              *
142  *        *pos = number of the searched element if found, else the        *
143  *        number of the first element that is larger than key.            *
144  **************************************************************************/
145 /*
146  * For those not familiar with binary search: lbound is the leftmost item
147  * that it could be, rbound the rightmost item that it could be.  We examine
148  * the item halfway between lbound and rbound, and that tells us either
149  * that we can increase lbound, or decrease rbound, or that we have found it,
150  * or if lbound <= rbound that there are no possible items, and we have not
151  * found it. With each examination we cut the number of possible items it
152  * could be by one more than half rounded down, or we find it.
153  */
bin_search(const void * key,const void * base,int num,int width,int * pos)154 static inline int bin_search(const void *key,	/* Key to search for. */
155 			     const void *base,	/* First item in the array. */
156 			     int num,	/* Number of items in the array. */
157 			     /*
158 			      * Item size in the array.  searched. Lest the
159 			      * reader be confused, note that this is crafted
160 			      * as a general function, and when it is applied
161 			      * specifically to the array of item headers in a
162 			      * node, width is actually the item header size
163 			      * not the item size.
164 			      */
165 			     int width,
166 			     int *pos /* Number of the searched for element. */
167     )
168 {
169 	int rbound, lbound, j;
170 
171 	for (j = ((rbound = num - 1) + (lbound = 0)) / 2;
172 	     lbound <= rbound; j = (rbound + lbound) / 2)
173 		switch (comp_keys
174 			((struct reiserfs_key *)((char *)base + j * width),
175 			 (struct cpu_key *)key)) {
176 		case -1:
177 			lbound = j + 1;
178 			continue;
179 		case 1:
180 			rbound = j - 1;
181 			continue;
182 		case 0:
183 			*pos = j;
184 			return ITEM_FOUND;	/* Key found in the array.  */
185 		}
186 
187 	/*
188 	 * bin_search did not find given key, it returns position of key,
189 	 * that is minimal and greater than the given one.
190 	 */
191 	*pos = lbound;
192 	return ITEM_NOT_FOUND;
193 }
194 
195 
196 /* Minimal possible key. It is never in the tree. */
197 const struct reiserfs_key MIN_KEY = { 0, 0, {{0, 0},} };
198 
199 /* Maximal possible key. It is never in the tree. */
200 static const struct reiserfs_key MAX_KEY = {
201 	cpu_to_le32(0xffffffff),
202 	cpu_to_le32(0xffffffff),
203 	{{cpu_to_le32(0xffffffff),
204 	  cpu_to_le32(0xffffffff)},}
205 };
206 
207 /*
208  * Get delimiting key of the buffer by looking for it in the buffers in the
209  * path, starting from the bottom of the path, and going upwards.  We must
210  * check the path's validity at each step.  If the key is not in the path,
211  * there is no delimiting key in the tree (buffer is first or last buffer
212  * in tree), and in this case we return a special key, either MIN_KEY or
213  * MAX_KEY.
214  */
get_lkey(const struct treepath * chk_path,const struct super_block * sb)215 static inline const struct reiserfs_key *get_lkey(const struct treepath *chk_path,
216 						  const struct super_block *sb)
217 {
218 	int position, path_offset = chk_path->path_length;
219 	struct buffer_head *parent;
220 
221 	RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET,
222 	       "PAP-5010: invalid offset in the path");
223 
224 	/* While not higher in path than first element. */
225 	while (path_offset-- > FIRST_PATH_ELEMENT_OFFSET) {
226 
227 		RFALSE(!buffer_uptodate
228 		       (PATH_OFFSET_PBUFFER(chk_path, path_offset)),
229 		       "PAP-5020: parent is not uptodate");
230 
231 		/* Parent at the path is not in the tree now. */
232 		if (!B_IS_IN_TREE
233 		    (parent =
234 		     PATH_OFFSET_PBUFFER(chk_path, path_offset)))
235 			return &MAX_KEY;
236 		/* Check whether position in the parent is correct. */
237 		if ((position =
238 		     PATH_OFFSET_POSITION(chk_path,
239 					  path_offset)) >
240 		    B_NR_ITEMS(parent))
241 			return &MAX_KEY;
242 		/* Check whether parent at the path really points to the child. */
243 		if (B_N_CHILD_NUM(parent, position) !=
244 		    PATH_OFFSET_PBUFFER(chk_path,
245 					path_offset + 1)->b_blocknr)
246 			return &MAX_KEY;
247 		/*
248 		 * Return delimiting key if position in the parent
249 		 * is not equal to zero.
250 		 */
251 		if (position)
252 			return internal_key(parent, position - 1);
253 	}
254 	/* Return MIN_KEY if we are in the root of the buffer tree. */
255 	if (PATH_OFFSET_PBUFFER(chk_path, FIRST_PATH_ELEMENT_OFFSET)->
256 	    b_blocknr == SB_ROOT_BLOCK(sb))
257 		return &MIN_KEY;
258 	return &MAX_KEY;
259 }
260 
261 /* Get delimiting key of the buffer at the path and its right neighbor. */
get_rkey(const struct treepath * chk_path,const struct super_block * sb)262 inline const struct reiserfs_key *get_rkey(const struct treepath *chk_path,
263 					   const struct super_block *sb)
264 {
265 	int position, path_offset = chk_path->path_length;
266 	struct buffer_head *parent;
267 
268 	RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET,
269 	       "PAP-5030: invalid offset in the path");
270 
271 	while (path_offset-- > FIRST_PATH_ELEMENT_OFFSET) {
272 
273 		RFALSE(!buffer_uptodate
274 		       (PATH_OFFSET_PBUFFER(chk_path, path_offset)),
275 		       "PAP-5040: parent is not uptodate");
276 
277 		/* Parent at the path is not in the tree now. */
278 		if (!B_IS_IN_TREE
279 		    (parent =
280 		     PATH_OFFSET_PBUFFER(chk_path, path_offset)))
281 			return &MIN_KEY;
282 		/* Check whether position in the parent is correct. */
283 		if ((position =
284 		     PATH_OFFSET_POSITION(chk_path,
285 					  path_offset)) >
286 		    B_NR_ITEMS(parent))
287 			return &MIN_KEY;
288 		/*
289 		 * Check whether parent at the path really points
290 		 * to the child.
291 		 */
292 		if (B_N_CHILD_NUM(parent, position) !=
293 		    PATH_OFFSET_PBUFFER(chk_path,
294 					path_offset + 1)->b_blocknr)
295 			return &MIN_KEY;
296 
297 		/*
298 		 * Return delimiting key if position in the parent
299 		 * is not the last one.
300 		 */
301 		if (position != B_NR_ITEMS(parent))
302 			return internal_key(parent, position);
303 	}
304 
305 	/* Return MAX_KEY if we are in the root of the buffer tree. */
306 	if (PATH_OFFSET_PBUFFER(chk_path, FIRST_PATH_ELEMENT_OFFSET)->
307 	    b_blocknr == SB_ROOT_BLOCK(sb))
308 		return &MAX_KEY;
309 	return &MIN_KEY;
310 }
311 
312 /*
313  * Check whether a key is contained in the tree rooted from a buffer at a path.
314  * This works by looking at the left and right delimiting keys for the buffer
315  * in the last path_element in the path.  These delimiting keys are stored
316  * at least one level above that buffer in the tree. If the buffer is the
317  * first or last node in the tree order then one of the delimiting keys may
318  * be absent, and in this case get_lkey and get_rkey return a special key
319  * which is MIN_KEY or MAX_KEY.
320  */
key_in_buffer(struct treepath * chk_path,const struct cpu_key * key,struct super_block * sb)321 static inline int key_in_buffer(
322 				/* Path which should be checked. */
323 				struct treepath *chk_path,
324 				/* Key which should be checked. */
325 				const struct cpu_key *key,
326 				struct super_block *sb
327     )
328 {
329 
330 	RFALSE(!key || chk_path->path_length < FIRST_PATH_ELEMENT_OFFSET
331 	       || chk_path->path_length > MAX_HEIGHT,
332 	       "PAP-5050: pointer to the key(%p) is NULL or invalid path length(%d)",
333 	       key, chk_path->path_length);
334 	RFALSE(!PATH_PLAST_BUFFER(chk_path)->b_bdev,
335 	       "PAP-5060: device must not be NODEV");
336 
337 	if (comp_keys(get_lkey(chk_path, sb), key) == 1)
338 		/* left delimiting key is bigger, that the key we look for */
339 		return 0;
340 	/*  if ( comp_keys(key, get_rkey(chk_path, sb)) != -1 ) */
341 	if (comp_keys(get_rkey(chk_path, sb), key) != 1)
342 		/* key must be less than right delimitiing key */
343 		return 0;
344 	return 1;
345 }
346 
reiserfs_check_path(struct treepath * p)347 int reiserfs_check_path(struct treepath *p)
348 {
349 	RFALSE(p->path_length != ILLEGAL_PATH_ELEMENT_OFFSET,
350 	       "path not properly relsed");
351 	return 0;
352 }
353 
354 /*
355  * Drop the reference to each buffer in a path and restore
356  * dirty bits clean when preparing the buffer for the log.
357  * This version should only be called from fix_nodes()
358  */
pathrelse_and_restore(struct super_block * sb,struct treepath * search_path)359 void pathrelse_and_restore(struct super_block *sb,
360 			   struct treepath *search_path)
361 {
362 	int path_offset = search_path->path_length;
363 
364 	RFALSE(path_offset < ILLEGAL_PATH_ELEMENT_OFFSET,
365 	       "clm-4000: invalid path offset");
366 
367 	while (path_offset > ILLEGAL_PATH_ELEMENT_OFFSET) {
368 		struct buffer_head *bh;
369 		bh = PATH_OFFSET_PBUFFER(search_path, path_offset--);
370 		reiserfs_restore_prepared_buffer(sb, bh);
371 		brelse(bh);
372 	}
373 	search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET;
374 }
375 
376 /* Drop the reference to each buffer in a path */
pathrelse(struct treepath * search_path)377 void pathrelse(struct treepath *search_path)
378 {
379 	int path_offset = search_path->path_length;
380 
381 	RFALSE(path_offset < ILLEGAL_PATH_ELEMENT_OFFSET,
382 	       "PAP-5090: invalid path offset");
383 
384 	while (path_offset > ILLEGAL_PATH_ELEMENT_OFFSET)
385 		brelse(PATH_OFFSET_PBUFFER(search_path, path_offset--));
386 
387 	search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET;
388 }
389 
has_valid_deh_location(struct buffer_head * bh,struct item_head * ih)390 static int has_valid_deh_location(struct buffer_head *bh, struct item_head *ih)
391 {
392 	struct reiserfs_de_head *deh;
393 	int i;
394 
395 	deh = B_I_DEH(bh, ih);
396 	for (i = 0; i < ih_entry_count(ih); i++) {
397 		if (deh_location(&deh[i]) > ih_item_len(ih)) {
398 			reiserfs_warning(NULL, "reiserfs-5094",
399 					 "directory entry location seems wrong %h",
400 					 &deh[i]);
401 			return 0;
402 		}
403 	}
404 
405 	return 1;
406 }
407 
is_leaf(char * buf,int blocksize,struct buffer_head * bh)408 static int is_leaf(char *buf, int blocksize, struct buffer_head *bh)
409 {
410 	struct block_head *blkh;
411 	struct item_head *ih;
412 	int used_space;
413 	int prev_location;
414 	int i;
415 	int nr;
416 
417 	blkh = (struct block_head *)buf;
418 	if (blkh_level(blkh) != DISK_LEAF_NODE_LEVEL) {
419 		reiserfs_warning(NULL, "reiserfs-5080",
420 				 "this should be caught earlier");
421 		return 0;
422 	}
423 
424 	nr = blkh_nr_item(blkh);
425 	if (nr < 1 || nr > ((blocksize - BLKH_SIZE) / (IH_SIZE + MIN_ITEM_LEN))) {
426 		/* item number is too big or too small */
427 		reiserfs_warning(NULL, "reiserfs-5081",
428 				 "nr_item seems wrong: %z", bh);
429 		return 0;
430 	}
431 	ih = (struct item_head *)(buf + BLKH_SIZE) + nr - 1;
432 	used_space = BLKH_SIZE + IH_SIZE * nr + (blocksize - ih_location(ih));
433 
434 	/* free space does not match to calculated amount of use space */
435 	if (used_space != blocksize - blkh_free_space(blkh)) {
436 		reiserfs_warning(NULL, "reiserfs-5082",
437 				 "free space seems wrong: %z", bh);
438 		return 0;
439 	}
440 	/*
441 	 * FIXME: it is_leaf will hit performance too much - we may have
442 	 * return 1 here
443 	 */
444 
445 	/* check tables of item heads */
446 	ih = (struct item_head *)(buf + BLKH_SIZE);
447 	prev_location = blocksize;
448 	for (i = 0; i < nr; i++, ih++) {
449 		if (le_ih_k_type(ih) == TYPE_ANY) {
450 			reiserfs_warning(NULL, "reiserfs-5083",
451 					 "wrong item type for item %h",
452 					 ih);
453 			return 0;
454 		}
455 		if (ih_location(ih) >= blocksize
456 		    || ih_location(ih) < IH_SIZE * nr) {
457 			reiserfs_warning(NULL, "reiserfs-5084",
458 					 "item location seems wrong: %h",
459 					 ih);
460 			return 0;
461 		}
462 		if (ih_item_len(ih) < 1
463 		    || ih_item_len(ih) > MAX_ITEM_LEN(blocksize)) {
464 			reiserfs_warning(NULL, "reiserfs-5085",
465 					 "item length seems wrong: %h",
466 					 ih);
467 			return 0;
468 		}
469 		if (prev_location - ih_location(ih) != ih_item_len(ih)) {
470 			reiserfs_warning(NULL, "reiserfs-5086",
471 					 "item location seems wrong "
472 					 "(second one): %h", ih);
473 			return 0;
474 		}
475 		if (is_direntry_le_ih(ih)) {
476 			if (ih_item_len(ih) < (ih_entry_count(ih) * IH_SIZE)) {
477 				reiserfs_warning(NULL, "reiserfs-5093",
478 						 "item entry count seems wrong %h",
479 						 ih);
480 				return 0;
481 			}
482 			return has_valid_deh_location(bh, ih);
483 		}
484 		prev_location = ih_location(ih);
485 	}
486 
487 	/* one may imagine many more checks */
488 	return 1;
489 }
490 
491 /* returns 1 if buf looks like an internal node, 0 otherwise */
is_internal(char * buf,int blocksize,struct buffer_head * bh)492 static int is_internal(char *buf, int blocksize, struct buffer_head *bh)
493 {
494 	struct block_head *blkh;
495 	int nr;
496 	int used_space;
497 
498 	blkh = (struct block_head *)buf;
499 	nr = blkh_level(blkh);
500 	if (nr <= DISK_LEAF_NODE_LEVEL || nr > MAX_HEIGHT) {
501 		/* this level is not possible for internal nodes */
502 		reiserfs_warning(NULL, "reiserfs-5087",
503 				 "this should be caught earlier");
504 		return 0;
505 	}
506 
507 	nr = blkh_nr_item(blkh);
508 	/* for internal which is not root we might check min number of keys */
509 	if (nr > (blocksize - BLKH_SIZE - DC_SIZE) / (KEY_SIZE + DC_SIZE)) {
510 		reiserfs_warning(NULL, "reiserfs-5088",
511 				 "number of key seems wrong: %z", bh);
512 		return 0;
513 	}
514 
515 	used_space = BLKH_SIZE + KEY_SIZE * nr + DC_SIZE * (nr + 1);
516 	if (used_space != blocksize - blkh_free_space(blkh)) {
517 		reiserfs_warning(NULL, "reiserfs-5089",
518 				 "free space seems wrong: %z", bh);
519 		return 0;
520 	}
521 
522 	/* one may imagine many more checks */
523 	return 1;
524 }
525 
526 /*
527  * make sure that bh contains formatted node of reiserfs tree of
528  * 'level'-th level
529  */
is_tree_node(struct buffer_head * bh,int level)530 static int is_tree_node(struct buffer_head *bh, int level)
531 {
532 	if (B_LEVEL(bh) != level) {
533 		reiserfs_warning(NULL, "reiserfs-5090", "node level %d does "
534 				 "not match to the expected one %d",
535 				 B_LEVEL(bh), level);
536 		return 0;
537 	}
538 	if (level == DISK_LEAF_NODE_LEVEL)
539 		return is_leaf(bh->b_data, bh->b_size, bh);
540 
541 	return is_internal(bh->b_data, bh->b_size, bh);
542 }
543 
544 #define SEARCH_BY_KEY_READA 16
545 
546 /*
547  * The function is NOT SCHEDULE-SAFE!
548  * It might unlock the write lock if we needed to wait for a block
549  * to be read. Note that in this case it won't recover the lock to avoid
550  * high contention resulting from too much lock requests, especially
551  * the caller (search_by_key) will perform other schedule-unsafe
552  * operations just after calling this function.
553  *
554  * @return depth of lock to be restored after read completes
555  */
search_by_key_reada(struct super_block * s,struct buffer_head ** bh,b_blocknr_t * b,int num)556 static int search_by_key_reada(struct super_block *s,
557 				struct buffer_head **bh,
558 				b_blocknr_t *b, int num)
559 {
560 	int i, j;
561 	int depth = -1;
562 
563 	for (i = 0; i < num; i++) {
564 		bh[i] = sb_getblk(s, b[i]);
565 	}
566 	/*
567 	 * We are going to read some blocks on which we
568 	 * have a reference. It's safe, though we might be
569 	 * reading blocks concurrently changed if we release
570 	 * the lock. But it's still fine because we check later
571 	 * if the tree changed
572 	 */
573 	for (j = 0; j < i; j++) {
574 		/*
575 		 * note, this needs attention if we are getting rid of the BKL
576 		 * you have to make sure the prepared bit isn't set on this
577 		 * buffer
578 		 */
579 		if (!buffer_uptodate(bh[j])) {
580 			if (depth == -1)
581 				depth = reiserfs_write_unlock_nested(s);
582 			ll_rw_block(REQ_OP_READ, REQ_RAHEAD, 1, bh + j);
583 		}
584 		brelse(bh[j]);
585 	}
586 	return depth;
587 }
588 
589 /*
590  * This function fills up the path from the root to the leaf as it
591  * descends the tree looking for the key.  It uses reiserfs_bread to
592  * try to find buffers in the cache given their block number.  If it
593  * does not find them in the cache it reads them from disk.  For each
594  * node search_by_key finds using reiserfs_bread it then uses
595  * bin_search to look through that node.  bin_search will find the
596  * position of the block_number of the next node if it is looking
597  * through an internal node.  If it is looking through a leaf node
598  * bin_search will find the position of the item which has key either
599  * equal to given key, or which is the maximal key less than the given
600  * key.  search_by_key returns a path that must be checked for the
601  * correctness of the top of the path but need not be checked for the
602  * correctness of the bottom of the path
603  */
604 /*
605  * search_by_key - search for key (and item) in stree
606  * @sb: superblock
607  * @key: pointer to key to search for
608  * @search_path: Allocated and initialized struct treepath; Returned filled
609  *		 on success.
610  * @stop_level: How far down the tree to search, Use DISK_LEAF_NODE_LEVEL to
611  *		stop at leaf level.
612  *
613  * The function is NOT SCHEDULE-SAFE!
614  */
search_by_key(struct super_block * sb,const struct cpu_key * key,struct treepath * search_path,int stop_level)615 int search_by_key(struct super_block *sb, const struct cpu_key *key,
616 		  struct treepath *search_path, int stop_level)
617 {
618 	b_blocknr_t block_number;
619 	int expected_level;
620 	struct buffer_head *bh;
621 	struct path_element *last_element;
622 	int node_level, retval;
623 	int right_neighbor_of_leaf_node;
624 	int fs_gen;
625 	struct buffer_head *reada_bh[SEARCH_BY_KEY_READA];
626 	b_blocknr_t reada_blocks[SEARCH_BY_KEY_READA];
627 	int reada_count = 0;
628 
629 #ifdef CONFIG_REISERFS_CHECK
630 	int repeat_counter = 0;
631 #endif
632 
633 	PROC_INFO_INC(sb, search_by_key);
634 
635 	/*
636 	 * As we add each node to a path we increase its count.  This means
637 	 * that we must be careful to release all nodes in a path before we
638 	 * either discard the path struct or re-use the path struct, as we
639 	 * do here.
640 	 */
641 
642 	pathrelse(search_path);
643 
644 	right_neighbor_of_leaf_node = 0;
645 
646 	/*
647 	 * With each iteration of this loop we search through the items in the
648 	 * current node, and calculate the next current node(next path element)
649 	 * for the next iteration of this loop..
650 	 */
651 	block_number = SB_ROOT_BLOCK(sb);
652 	expected_level = -1;
653 	while (1) {
654 
655 #ifdef CONFIG_REISERFS_CHECK
656 		if (!(++repeat_counter % 50000))
657 			reiserfs_warning(sb, "PAP-5100",
658 					 "%s: there were %d iterations of "
659 					 "while loop looking for key %K",
660 					 current->comm, repeat_counter,
661 					 key);
662 #endif
663 
664 		/* prep path to have another element added to it. */
665 		last_element =
666 		    PATH_OFFSET_PELEMENT(search_path,
667 					 ++search_path->path_length);
668 		fs_gen = get_generation(sb);
669 
670 		/*
671 		 * Read the next tree node, and set the last element
672 		 * in the path to have a pointer to it.
673 		 */
674 		if ((bh = last_element->pe_buffer =
675 		     sb_getblk(sb, block_number))) {
676 
677 			/*
678 			 * We'll need to drop the lock if we encounter any
679 			 * buffers that need to be read. If all of them are
680 			 * already up to date, we don't need to drop the lock.
681 			 */
682 			int depth = -1;
683 
684 			if (!buffer_uptodate(bh) && reada_count > 1)
685 				depth = search_by_key_reada(sb, reada_bh,
686 						    reada_blocks, reada_count);
687 
688 			if (!buffer_uptodate(bh) && depth == -1)
689 				depth = reiserfs_write_unlock_nested(sb);
690 
691 			ll_rw_block(REQ_OP_READ, 0, 1, &bh);
692 			wait_on_buffer(bh);
693 
694 			if (depth != -1)
695 				reiserfs_write_lock_nested(sb, depth);
696 			if (!buffer_uptodate(bh))
697 				goto io_error;
698 		} else {
699 io_error:
700 			search_path->path_length--;
701 			pathrelse(search_path);
702 			return IO_ERROR;
703 		}
704 		reada_count = 0;
705 		if (expected_level == -1)
706 			expected_level = SB_TREE_HEIGHT(sb);
707 		expected_level--;
708 
709 		/*
710 		 * It is possible that schedule occurred. We must check
711 		 * whether the key to search is still in the tree rooted
712 		 * from the current buffer. If not then repeat search
713 		 * from the root.
714 		 */
715 		if (fs_changed(fs_gen, sb) &&
716 		    (!B_IS_IN_TREE(bh) ||
717 		     B_LEVEL(bh) != expected_level ||
718 		     !key_in_buffer(search_path, key, sb))) {
719 			PROC_INFO_INC(sb, search_by_key_fs_changed);
720 			PROC_INFO_INC(sb, search_by_key_restarted);
721 			PROC_INFO_INC(sb,
722 				      sbk_restarted[expected_level - 1]);
723 			pathrelse(search_path);
724 
725 			/*
726 			 * Get the root block number so that we can
727 			 * repeat the search starting from the root.
728 			 */
729 			block_number = SB_ROOT_BLOCK(sb);
730 			expected_level = -1;
731 			right_neighbor_of_leaf_node = 0;
732 
733 			/* repeat search from the root */
734 			continue;
735 		}
736 
737 		/*
738 		 * only check that the key is in the buffer if key is not
739 		 * equal to the MAX_KEY. Latter case is only possible in
740 		 * "finish_unfinished()" processing during mount.
741 		 */
742 		RFALSE(comp_keys(&MAX_KEY, key) &&
743 		       !key_in_buffer(search_path, key, sb),
744 		       "PAP-5130: key is not in the buffer");
745 #ifdef CONFIG_REISERFS_CHECK
746 		if (REISERFS_SB(sb)->cur_tb) {
747 			print_cur_tb("5140");
748 			reiserfs_panic(sb, "PAP-5140",
749 				       "schedule occurred in do_balance!");
750 		}
751 #endif
752 
753 		/*
754 		 * make sure, that the node contents look like a node of
755 		 * certain level
756 		 */
757 		if (!is_tree_node(bh, expected_level)) {
758 			reiserfs_error(sb, "vs-5150",
759 				       "invalid format found in block %ld. "
760 				       "Fsck?", bh->b_blocknr);
761 			pathrelse(search_path);
762 			return IO_ERROR;
763 		}
764 
765 		/* ok, we have acquired next formatted node in the tree */
766 		node_level = B_LEVEL(bh);
767 
768 		PROC_INFO_BH_STAT(sb, bh, node_level - 1);
769 
770 		RFALSE(node_level < stop_level,
771 		       "vs-5152: tree level (%d) is less than stop level (%d)",
772 		       node_level, stop_level);
773 
774 		retval = bin_search(key, item_head(bh, 0),
775 				      B_NR_ITEMS(bh),
776 				      (node_level ==
777 				       DISK_LEAF_NODE_LEVEL) ? IH_SIZE :
778 				      KEY_SIZE,
779 				      &last_element->pe_position);
780 		if (node_level == stop_level) {
781 			return retval;
782 		}
783 
784 		/* we are not in the stop level */
785 		/*
786 		 * item has been found, so we choose the pointer which
787 		 * is to the right of the found one
788 		 */
789 		if (retval == ITEM_FOUND)
790 			last_element->pe_position++;
791 
792 		/*
793 		 * if item was not found we choose the position which is to
794 		 * the left of the found item. This requires no code,
795 		 * bin_search did it already.
796 		 */
797 
798 		/*
799 		 * So we have chosen a position in the current node which is
800 		 * an internal node.  Now we calculate child block number by
801 		 * position in the node.
802 		 */
803 		block_number =
804 		    B_N_CHILD_NUM(bh, last_element->pe_position);
805 
806 		/*
807 		 * if we are going to read leaf nodes, try for read
808 		 * ahead as well
809 		 */
810 		if ((search_path->reada & PATH_READA) &&
811 		    node_level == DISK_LEAF_NODE_LEVEL + 1) {
812 			int pos = last_element->pe_position;
813 			int limit = B_NR_ITEMS(bh);
814 			struct reiserfs_key *le_key;
815 
816 			if (search_path->reada & PATH_READA_BACK)
817 				limit = 0;
818 			while (reada_count < SEARCH_BY_KEY_READA) {
819 				if (pos == limit)
820 					break;
821 				reada_blocks[reada_count++] =
822 				    B_N_CHILD_NUM(bh, pos);
823 				if (search_path->reada & PATH_READA_BACK)
824 					pos--;
825 				else
826 					pos++;
827 
828 				/*
829 				 * check to make sure we're in the same object
830 				 */
831 				le_key = internal_key(bh, pos);
832 				if (le32_to_cpu(le_key->k_objectid) !=
833 				    key->on_disk_key.k_objectid) {
834 					break;
835 				}
836 			}
837 		}
838 	}
839 }
840 
841 /*
842  * Form the path to an item and position in this item which contains
843  * file byte defined by key. If there is no such item
844  * corresponding to the key, we point the path to the item with
845  * maximal key less than key, and *pos_in_item is set to one
846  * past the last entry/byte in the item.  If searching for entry in a
847  * directory item, and it is not found, *pos_in_item is set to one
848  * entry more than the entry with maximal key which is less than the
849  * sought key.
850  *
851  * Note that if there is no entry in this same node which is one more,
852  * then we point to an imaginary entry.  for direct items, the
853  * position is in units of bytes, for indirect items the position is
854  * in units of blocknr entries, for directory items the position is in
855  * units of directory entries.
856  */
857 /* The function is NOT SCHEDULE-SAFE! */
search_for_position_by_key(struct super_block * sb,const struct cpu_key * p_cpu_key,struct treepath * search_path)858 int search_for_position_by_key(struct super_block *sb,
859 			       /* Key to search (cpu variable) */
860 			       const struct cpu_key *p_cpu_key,
861 			       /* Filled up by this function. */
862 			       struct treepath *search_path)
863 {
864 	struct item_head *p_le_ih;	/* pointer to on-disk structure */
865 	int blk_size;
866 	loff_t item_offset, offset;
867 	struct reiserfs_dir_entry de;
868 	int retval;
869 
870 	/* If searching for directory entry. */
871 	if (is_direntry_cpu_key(p_cpu_key))
872 		return search_by_entry_key(sb, p_cpu_key, search_path,
873 					   &de);
874 
875 	/* If not searching for directory entry. */
876 
877 	/* If item is found. */
878 	retval = search_item(sb, p_cpu_key, search_path);
879 	if (retval == IO_ERROR)
880 		return retval;
881 	if (retval == ITEM_FOUND) {
882 
883 		RFALSE(!ih_item_len
884 		       (item_head
885 			(PATH_PLAST_BUFFER(search_path),
886 			 PATH_LAST_POSITION(search_path))),
887 		       "PAP-5165: item length equals zero");
888 
889 		pos_in_item(search_path) = 0;
890 		return POSITION_FOUND;
891 	}
892 
893 	RFALSE(!PATH_LAST_POSITION(search_path),
894 	       "PAP-5170: position equals zero");
895 
896 	/* Item is not found. Set path to the previous item. */
897 	p_le_ih =
898 	    item_head(PATH_PLAST_BUFFER(search_path),
899 			   --PATH_LAST_POSITION(search_path));
900 	blk_size = sb->s_blocksize;
901 
902 	if (comp_short_keys(&p_le_ih->ih_key, p_cpu_key))
903 		return FILE_NOT_FOUND;
904 
905 	/* FIXME: quite ugly this far */
906 
907 	item_offset = le_ih_k_offset(p_le_ih);
908 	offset = cpu_key_k_offset(p_cpu_key);
909 
910 	/* Needed byte is contained in the item pointed to by the path. */
911 	if (item_offset <= offset &&
912 	    item_offset + op_bytes_number(p_le_ih, blk_size) > offset) {
913 		pos_in_item(search_path) = offset - item_offset;
914 		if (is_indirect_le_ih(p_le_ih)) {
915 			pos_in_item(search_path) /= blk_size;
916 		}
917 		return POSITION_FOUND;
918 	}
919 
920 	/*
921 	 * Needed byte is not contained in the item pointed to by the
922 	 * path. Set pos_in_item out of the item.
923 	 */
924 	if (is_indirect_le_ih(p_le_ih))
925 		pos_in_item(search_path) =
926 		    ih_item_len(p_le_ih) / UNFM_P_SIZE;
927 	else
928 		pos_in_item(search_path) = ih_item_len(p_le_ih);
929 
930 	return POSITION_NOT_FOUND;
931 }
932 
933 /* Compare given item and item pointed to by the path. */
comp_items(const struct item_head * stored_ih,const struct treepath * path)934 int comp_items(const struct item_head *stored_ih, const struct treepath *path)
935 {
936 	struct buffer_head *bh = PATH_PLAST_BUFFER(path);
937 	struct item_head *ih;
938 
939 	/* Last buffer at the path is not in the tree. */
940 	if (!B_IS_IN_TREE(bh))
941 		return 1;
942 
943 	/* Last path position is invalid. */
944 	if (PATH_LAST_POSITION(path) >= B_NR_ITEMS(bh))
945 		return 1;
946 
947 	/* we need only to know, whether it is the same item */
948 	ih = tp_item_head(path);
949 	return memcmp(stored_ih, ih, IH_SIZE);
950 }
951 
952 /* unformatted nodes are not logged anymore, ever.  This is safe now */
953 #define held_by_others(bh) (atomic_read(&(bh)->b_count) > 1)
954 
955 /* block can not be forgotten as it is in I/O or held by someone */
956 #define block_in_use(bh) (buffer_locked(bh) || (held_by_others(bh)))
957 
958 /* prepare for delete or cut of direct item */
prepare_for_direct_item(struct treepath * path,struct item_head * le_ih,struct inode * inode,loff_t new_file_length,int * cut_size)959 static inline int prepare_for_direct_item(struct treepath *path,
960 					  struct item_head *le_ih,
961 					  struct inode *inode,
962 					  loff_t new_file_length, int *cut_size)
963 {
964 	loff_t round_len;
965 
966 	if (new_file_length == max_reiserfs_offset(inode)) {
967 		/* item has to be deleted */
968 		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
969 		return M_DELETE;
970 	}
971 	/* new file gets truncated */
972 	if (get_inode_item_key_version(inode) == KEY_FORMAT_3_6) {
973 		round_len = ROUND_UP(new_file_length);
974 		/* this was new_file_length < le_ih ... */
975 		if (round_len < le_ih_k_offset(le_ih)) {
976 			*cut_size = -(IH_SIZE + ih_item_len(le_ih));
977 			return M_DELETE;	/* Delete this item. */
978 		}
979 		/* Calculate first position and size for cutting from item. */
980 		pos_in_item(path) = round_len - (le_ih_k_offset(le_ih) - 1);
981 		*cut_size = -(ih_item_len(le_ih) - pos_in_item(path));
982 
983 		return M_CUT;	/* Cut from this item. */
984 	}
985 
986 	/* old file: items may have any length */
987 
988 	if (new_file_length < le_ih_k_offset(le_ih)) {
989 		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
990 		return M_DELETE;	/* Delete this item. */
991 	}
992 
993 	/* Calculate first position and size for cutting from item. */
994 	*cut_size = -(ih_item_len(le_ih) -
995 		      (pos_in_item(path) =
996 		       new_file_length + 1 - le_ih_k_offset(le_ih)));
997 	return M_CUT;		/* Cut from this item. */
998 }
999 
prepare_for_direntry_item(struct treepath * path,struct item_head * le_ih,struct inode * inode,loff_t new_file_length,int * cut_size)1000 static inline int prepare_for_direntry_item(struct treepath *path,
1001 					    struct item_head *le_ih,
1002 					    struct inode *inode,
1003 					    loff_t new_file_length,
1004 					    int *cut_size)
1005 {
1006 	if (le_ih_k_offset(le_ih) == DOT_OFFSET &&
1007 	    new_file_length == max_reiserfs_offset(inode)) {
1008 		RFALSE(ih_entry_count(le_ih) != 2,
1009 		       "PAP-5220: incorrect empty directory item (%h)", le_ih);
1010 		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
1011 		/* Delete the directory item containing "." and ".." entry. */
1012 		return M_DELETE;
1013 	}
1014 
1015 	if (ih_entry_count(le_ih) == 1) {
1016 		/*
1017 		 * Delete the directory item such as there is one record only
1018 		 * in this item
1019 		 */
1020 		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
1021 		return M_DELETE;
1022 	}
1023 
1024 	/* Cut one record from the directory item. */
1025 	*cut_size =
1026 	    -(DEH_SIZE +
1027 	      entry_length(get_last_bh(path), le_ih, pos_in_item(path)));
1028 	return M_CUT;
1029 }
1030 
1031 #define JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD (2 * JOURNAL_PER_BALANCE_CNT + 1)
1032 
1033 /*
1034  * If the path points to a directory or direct item, calculate mode
1035  * and the size cut, for balance.
1036  * If the path points to an indirect item, remove some number of its
1037  * unformatted nodes.
1038  * In case of file truncate calculate whether this item must be
1039  * deleted/truncated or last unformatted node of this item will be
1040  * converted to a direct item.
1041  * This function returns a determination of what balance mode the
1042  * calling function should employ.
1043  */
prepare_for_delete_or_cut(struct reiserfs_transaction_handle * th,struct inode * inode,struct treepath * path,const struct cpu_key * item_key,int * removed,int * cut_size,unsigned long long new_file_length)1044 static char prepare_for_delete_or_cut(struct reiserfs_transaction_handle *th,
1045 				      struct inode *inode,
1046 				      struct treepath *path,
1047 				      const struct cpu_key *item_key,
1048 				      /*
1049 				       * Number of unformatted nodes
1050 				       * which were removed from end
1051 				       * of the file.
1052 				       */
1053 				      int *removed,
1054 				      int *cut_size,
1055 				      /* MAX_KEY_OFFSET in case of delete. */
1056 				      unsigned long long new_file_length
1057     )
1058 {
1059 	struct super_block *sb = inode->i_sb;
1060 	struct item_head *p_le_ih = tp_item_head(path);
1061 	struct buffer_head *bh = PATH_PLAST_BUFFER(path);
1062 
1063 	BUG_ON(!th->t_trans_id);
1064 
1065 	/* Stat_data item. */
1066 	if (is_statdata_le_ih(p_le_ih)) {
1067 
1068 		RFALSE(new_file_length != max_reiserfs_offset(inode),
1069 		       "PAP-5210: mode must be M_DELETE");
1070 
1071 		*cut_size = -(IH_SIZE + ih_item_len(p_le_ih));
1072 		return M_DELETE;
1073 	}
1074 
1075 	/* Directory item. */
1076 	if (is_direntry_le_ih(p_le_ih))
1077 		return prepare_for_direntry_item(path, p_le_ih, inode,
1078 						 new_file_length,
1079 						 cut_size);
1080 
1081 	/* Direct item. */
1082 	if (is_direct_le_ih(p_le_ih))
1083 		return prepare_for_direct_item(path, p_le_ih, inode,
1084 					       new_file_length, cut_size);
1085 
1086 	/* Case of an indirect item. */
1087 	{
1088 	    int blk_size = sb->s_blocksize;
1089 	    struct item_head s_ih;
1090 	    int need_re_search;
1091 	    int delete = 0;
1092 	    int result = M_CUT;
1093 	    int pos = 0;
1094 
1095 	    if ( new_file_length == max_reiserfs_offset (inode) ) {
1096 		/*
1097 		 * prepare_for_delete_or_cut() is called by
1098 		 * reiserfs_delete_item()
1099 		 */
1100 		new_file_length = 0;
1101 		delete = 1;
1102 	    }
1103 
1104 	    do {
1105 		need_re_search = 0;
1106 		*cut_size = 0;
1107 		bh = PATH_PLAST_BUFFER(path);
1108 		copy_item_head(&s_ih, tp_item_head(path));
1109 		pos = I_UNFM_NUM(&s_ih);
1110 
1111 		while (le_ih_k_offset (&s_ih) + (pos - 1) * blk_size > new_file_length) {
1112 		    __le32 *unfm;
1113 		    __u32 block;
1114 
1115 		    /*
1116 		     * Each unformatted block deletion may involve
1117 		     * one additional bitmap block into the transaction,
1118 		     * thereby the initial journal space reservation
1119 		     * might not be enough.
1120 		     */
1121 		    if (!delete && (*cut_size) != 0 &&
1122 			reiserfs_transaction_free_space(th) < JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD)
1123 			break;
1124 
1125 		    unfm = (__le32 *)ih_item_body(bh, &s_ih) + pos - 1;
1126 		    block = get_block_num(unfm, 0);
1127 
1128 		    if (block != 0) {
1129 			reiserfs_prepare_for_journal(sb, bh, 1);
1130 			put_block_num(unfm, 0, 0);
1131 			journal_mark_dirty(th, bh);
1132 			reiserfs_free_block(th, inode, block, 1);
1133 		    }
1134 
1135 		    reiserfs_cond_resched(sb);
1136 
1137 		    if (item_moved (&s_ih, path))  {
1138 			need_re_search = 1;
1139 			break;
1140 		    }
1141 
1142 		    pos --;
1143 		    (*removed)++;
1144 		    (*cut_size) -= UNFM_P_SIZE;
1145 
1146 		    if (pos == 0) {
1147 			(*cut_size) -= IH_SIZE;
1148 			result = M_DELETE;
1149 			break;
1150 		    }
1151 		}
1152 		/*
1153 		 * a trick.  If the buffer has been logged, this will
1154 		 * do nothing.  If we've broken the loop without logging
1155 		 * it, it will restore the buffer
1156 		 */
1157 		reiserfs_restore_prepared_buffer(sb, bh);
1158 	    } while (need_re_search &&
1159 		     search_for_position_by_key(sb, item_key, path) == POSITION_FOUND);
1160 	    pos_in_item(path) = pos * UNFM_P_SIZE;
1161 
1162 	    if (*cut_size == 0) {
1163 		/*
1164 		 * Nothing was cut. maybe convert last unformatted node to the
1165 		 * direct item?
1166 		 */
1167 		result = M_CONVERT;
1168 	    }
1169 	    return result;
1170 	}
1171 }
1172 
1173 /* Calculate number of bytes which will be deleted or cut during balance */
calc_deleted_bytes_number(struct tree_balance * tb,char mode)1174 static int calc_deleted_bytes_number(struct tree_balance *tb, char mode)
1175 {
1176 	int del_size;
1177 	struct item_head *p_le_ih = tp_item_head(tb->tb_path);
1178 
1179 	if (is_statdata_le_ih(p_le_ih))
1180 		return 0;
1181 
1182 	del_size =
1183 	    (mode ==
1184 	     M_DELETE) ? ih_item_len(p_le_ih) : -tb->insert_size[0];
1185 	if (is_direntry_le_ih(p_le_ih)) {
1186 		/*
1187 		 * return EMPTY_DIR_SIZE; We delete emty directories only.
1188 		 * we can't use EMPTY_DIR_SIZE, as old format dirs have a
1189 		 * different empty size.  ick. FIXME, is this right?
1190 		 */
1191 		return del_size;
1192 	}
1193 
1194 	if (is_indirect_le_ih(p_le_ih))
1195 		del_size = (del_size / UNFM_P_SIZE) *
1196 				(PATH_PLAST_BUFFER(tb->tb_path)->b_size);
1197 	return del_size;
1198 }
1199 
init_tb_struct(struct reiserfs_transaction_handle * th,struct tree_balance * tb,struct super_block * sb,struct treepath * path,int size)1200 static void init_tb_struct(struct reiserfs_transaction_handle *th,
1201 			   struct tree_balance *tb,
1202 			   struct super_block *sb,
1203 			   struct treepath *path, int size)
1204 {
1205 
1206 	BUG_ON(!th->t_trans_id);
1207 
1208 	memset(tb, '\0', sizeof(struct tree_balance));
1209 	tb->transaction_handle = th;
1210 	tb->tb_sb = sb;
1211 	tb->tb_path = path;
1212 	PATH_OFFSET_PBUFFER(path, ILLEGAL_PATH_ELEMENT_OFFSET) = NULL;
1213 	PATH_OFFSET_POSITION(path, ILLEGAL_PATH_ELEMENT_OFFSET) = 0;
1214 	tb->insert_size[0] = size;
1215 }
1216 
padd_item(char * item,int total_length,int length)1217 void padd_item(char *item, int total_length, int length)
1218 {
1219 	int i;
1220 
1221 	for (i = total_length; i > length;)
1222 		item[--i] = 0;
1223 }
1224 
1225 #ifdef REISERQUOTA_DEBUG
key2type(struct reiserfs_key * ih)1226 char key2type(struct reiserfs_key *ih)
1227 {
1228 	if (is_direntry_le_key(2, ih))
1229 		return 'd';
1230 	if (is_direct_le_key(2, ih))
1231 		return 'D';
1232 	if (is_indirect_le_key(2, ih))
1233 		return 'i';
1234 	if (is_statdata_le_key(2, ih))
1235 		return 's';
1236 	return 'u';
1237 }
1238 
head2type(struct item_head * ih)1239 char head2type(struct item_head *ih)
1240 {
1241 	if (is_direntry_le_ih(ih))
1242 		return 'd';
1243 	if (is_direct_le_ih(ih))
1244 		return 'D';
1245 	if (is_indirect_le_ih(ih))
1246 		return 'i';
1247 	if (is_statdata_le_ih(ih))
1248 		return 's';
1249 	return 'u';
1250 }
1251 #endif
1252 
1253 /*
1254  * Delete object item.
1255  * th       - active transaction handle
1256  * path     - path to the deleted item
1257  * item_key - key to search for the deleted item
1258  * indode   - used for updating i_blocks and quotas
1259  * un_bh    - NULL or unformatted node pointer
1260  */
reiserfs_delete_item(struct reiserfs_transaction_handle * th,struct treepath * path,const struct cpu_key * item_key,struct inode * inode,struct buffer_head * un_bh)1261 int reiserfs_delete_item(struct reiserfs_transaction_handle *th,
1262 			 struct treepath *path, const struct cpu_key *item_key,
1263 			 struct inode *inode, struct buffer_head *un_bh)
1264 {
1265 	struct super_block *sb = inode->i_sb;
1266 	struct tree_balance s_del_balance;
1267 	struct item_head s_ih;
1268 	struct item_head *q_ih;
1269 	int quota_cut_bytes;
1270 	int ret_value, del_size, removed;
1271 	int depth;
1272 
1273 #ifdef CONFIG_REISERFS_CHECK
1274 	char mode;
1275 	int iter = 0;
1276 #endif
1277 
1278 	BUG_ON(!th->t_trans_id);
1279 
1280 	init_tb_struct(th, &s_del_balance, sb, path,
1281 		       0 /*size is unknown */ );
1282 
1283 	while (1) {
1284 		removed = 0;
1285 
1286 #ifdef CONFIG_REISERFS_CHECK
1287 		iter++;
1288 		mode =
1289 #endif
1290 		    prepare_for_delete_or_cut(th, inode, path,
1291 					      item_key, &removed,
1292 					      &del_size,
1293 					      max_reiserfs_offset(inode));
1294 
1295 		RFALSE(mode != M_DELETE, "PAP-5320: mode must be M_DELETE");
1296 
1297 		copy_item_head(&s_ih, tp_item_head(path));
1298 		s_del_balance.insert_size[0] = del_size;
1299 
1300 		ret_value = fix_nodes(M_DELETE, &s_del_balance, NULL, NULL);
1301 		if (ret_value != REPEAT_SEARCH)
1302 			break;
1303 
1304 		PROC_INFO_INC(sb, delete_item_restarted);
1305 
1306 		/* file system changed, repeat search */
1307 		ret_value =
1308 		    search_for_position_by_key(sb, item_key, path);
1309 		if (ret_value == IO_ERROR)
1310 			break;
1311 		if (ret_value == FILE_NOT_FOUND) {
1312 			reiserfs_warning(sb, "vs-5340",
1313 					 "no items of the file %K found",
1314 					 item_key);
1315 			break;
1316 		}
1317 	}			/* while (1) */
1318 
1319 	if (ret_value != CARRY_ON) {
1320 		unfix_nodes(&s_del_balance);
1321 		return 0;
1322 	}
1323 
1324 	/* reiserfs_delete_item returns item length when success */
1325 	ret_value = calc_deleted_bytes_number(&s_del_balance, M_DELETE);
1326 	q_ih = tp_item_head(path);
1327 	quota_cut_bytes = ih_item_len(q_ih);
1328 
1329 	/*
1330 	 * hack so the quota code doesn't have to guess if the file has a
1331 	 * tail.  On tail insert, we allocate quota for 1 unformatted node.
1332 	 * We test the offset because the tail might have been
1333 	 * split into multiple items, and we only want to decrement for
1334 	 * the unfm node once
1335 	 */
1336 	if (!S_ISLNK(inode->i_mode) && is_direct_le_ih(q_ih)) {
1337 		if ((le_ih_k_offset(q_ih) & (sb->s_blocksize - 1)) == 1) {
1338 			quota_cut_bytes = sb->s_blocksize + UNFM_P_SIZE;
1339 		} else {
1340 			quota_cut_bytes = 0;
1341 		}
1342 	}
1343 
1344 	if (un_bh) {
1345 		int off;
1346 		char *data;
1347 
1348 		/*
1349 		 * We are in direct2indirect conversion, so move tail contents
1350 		 * to the unformatted node
1351 		 */
1352 		/*
1353 		 * note, we do the copy before preparing the buffer because we
1354 		 * don't care about the contents of the unformatted node yet.
1355 		 * the only thing we really care about is the direct item's
1356 		 * data is in the unformatted node.
1357 		 *
1358 		 * Otherwise, we would have to call
1359 		 * reiserfs_prepare_for_journal on the unformatted node,
1360 		 * which might schedule, meaning we'd have to loop all the
1361 		 * way back up to the start of the while loop.
1362 		 *
1363 		 * The unformatted node must be dirtied later on.  We can't be
1364 		 * sure here if the entire tail has been deleted yet.
1365 		 *
1366 		 * un_bh is from the page cache (all unformatted nodes are
1367 		 * from the page cache) and might be a highmem page.  So, we
1368 		 * can't use un_bh->b_data.
1369 		 * -clm
1370 		 */
1371 
1372 		data = kmap_atomic(un_bh->b_page);
1373 		off = ((le_ih_k_offset(&s_ih) - 1) & (PAGE_SIZE - 1));
1374 		memcpy(data + off,
1375 		       ih_item_body(PATH_PLAST_BUFFER(path), &s_ih),
1376 		       ret_value);
1377 		kunmap_atomic(data);
1378 	}
1379 
1380 	/* Perform balancing after all resources have been collected at once. */
1381 	do_balance(&s_del_balance, NULL, NULL, M_DELETE);
1382 
1383 #ifdef REISERQUOTA_DEBUG
1384 	reiserfs_debug(sb, REISERFS_DEBUG_CODE,
1385 		       "reiserquota delete_item(): freeing %u, id=%u type=%c",
1386 		       quota_cut_bytes, inode->i_uid, head2type(&s_ih));
1387 #endif
1388 	depth = reiserfs_write_unlock_nested(inode->i_sb);
1389 	dquot_free_space_nodirty(inode, quota_cut_bytes);
1390 	reiserfs_write_lock_nested(inode->i_sb, depth);
1391 
1392 	/* Return deleted body length */
1393 	return ret_value;
1394 }
1395 
1396 /*
1397  * Summary Of Mechanisms For Handling Collisions Between Processes:
1398  *
1399  *  deletion of the body of the object is performed by iput(), with the
1400  *  result that if multiple processes are operating on a file, the
1401  *  deletion of the body of the file is deferred until the last process
1402  *  that has an open inode performs its iput().
1403  *
1404  *  writes and truncates are protected from collisions by use of
1405  *  semaphores.
1406  *
1407  *  creates, linking, and mknod are protected from collisions with other
1408  *  processes by making the reiserfs_add_entry() the last step in the
1409  *  creation, and then rolling back all changes if there was a collision.
1410  *  - Hans
1411 */
1412 
1413 /* this deletes item which never gets split */
reiserfs_delete_solid_item(struct reiserfs_transaction_handle * th,struct inode * inode,struct reiserfs_key * key)1414 void reiserfs_delete_solid_item(struct reiserfs_transaction_handle *th,
1415 				struct inode *inode, struct reiserfs_key *key)
1416 {
1417 	struct super_block *sb = th->t_super;
1418 	struct tree_balance tb;
1419 	INITIALIZE_PATH(path);
1420 	int item_len = 0;
1421 	int tb_init = 0;
1422 	struct cpu_key cpu_key;
1423 	int retval;
1424 	int quota_cut_bytes = 0;
1425 
1426 	BUG_ON(!th->t_trans_id);
1427 
1428 	le_key2cpu_key(&cpu_key, key);
1429 
1430 	while (1) {
1431 		retval = search_item(th->t_super, &cpu_key, &path);
1432 		if (retval == IO_ERROR) {
1433 			reiserfs_error(th->t_super, "vs-5350",
1434 				       "i/o failure occurred trying "
1435 				       "to delete %K", &cpu_key);
1436 			break;
1437 		}
1438 		if (retval != ITEM_FOUND) {
1439 			pathrelse(&path);
1440 			/*
1441 			 * No need for a warning, if there is just no free
1442 			 * space to insert '..' item into the
1443 			 * newly-created subdir
1444 			 */
1445 			if (!
1446 			    ((unsigned long long)
1447 			     GET_HASH_VALUE(le_key_k_offset
1448 					    (le_key_version(key), key)) == 0
1449 			     && (unsigned long long)
1450 			     GET_GENERATION_NUMBER(le_key_k_offset
1451 						   (le_key_version(key),
1452 						    key)) == 1))
1453 				reiserfs_warning(th->t_super, "vs-5355",
1454 						 "%k not found", key);
1455 			break;
1456 		}
1457 		if (!tb_init) {
1458 			tb_init = 1;
1459 			item_len = ih_item_len(tp_item_head(&path));
1460 			init_tb_struct(th, &tb, th->t_super, &path,
1461 				       -(IH_SIZE + item_len));
1462 		}
1463 		quota_cut_bytes = ih_item_len(tp_item_head(&path));
1464 
1465 		retval = fix_nodes(M_DELETE, &tb, NULL, NULL);
1466 		if (retval == REPEAT_SEARCH) {
1467 			PROC_INFO_INC(th->t_super, delete_solid_item_restarted);
1468 			continue;
1469 		}
1470 
1471 		if (retval == CARRY_ON) {
1472 			do_balance(&tb, NULL, NULL, M_DELETE);
1473 			/*
1474 			 * Should we count quota for item? (we don't
1475 			 * count quotas for save-links)
1476 			 */
1477 			if (inode) {
1478 				int depth;
1479 #ifdef REISERQUOTA_DEBUG
1480 				reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
1481 					       "reiserquota delete_solid_item(): freeing %u id=%u type=%c",
1482 					       quota_cut_bytes, inode->i_uid,
1483 					       key2type(key));
1484 #endif
1485 				depth = reiserfs_write_unlock_nested(sb);
1486 				dquot_free_space_nodirty(inode,
1487 							 quota_cut_bytes);
1488 				reiserfs_write_lock_nested(sb, depth);
1489 			}
1490 			break;
1491 		}
1492 
1493 		/* IO_ERROR, NO_DISK_SPACE, etc */
1494 		reiserfs_warning(th->t_super, "vs-5360",
1495 				 "could not delete %K due to fix_nodes failure",
1496 				 &cpu_key);
1497 		unfix_nodes(&tb);
1498 		break;
1499 	}
1500 
1501 	reiserfs_check_path(&path);
1502 }
1503 
reiserfs_delete_object(struct reiserfs_transaction_handle * th,struct inode * inode)1504 int reiserfs_delete_object(struct reiserfs_transaction_handle *th,
1505 			   struct inode *inode)
1506 {
1507 	int err;
1508 	inode->i_size = 0;
1509 	BUG_ON(!th->t_trans_id);
1510 
1511 	/* for directory this deletes item containing "." and ".." */
1512 	err =
1513 	    reiserfs_do_truncate(th, inode, NULL, 0 /*no timestamp updates */ );
1514 	if (err)
1515 		return err;
1516 
1517 #if defined( USE_INODE_GENERATION_COUNTER )
1518 	if (!old_format_only(th->t_super)) {
1519 		__le32 *inode_generation;
1520 
1521 		inode_generation =
1522 		    &REISERFS_SB(th->t_super)->s_rs->s_inode_generation;
1523 		le32_add_cpu(inode_generation, 1);
1524 	}
1525 /* USE_INODE_GENERATION_COUNTER */
1526 #endif
1527 	reiserfs_delete_solid_item(th, inode, INODE_PKEY(inode));
1528 
1529 	return err;
1530 }
1531 
unmap_buffers(struct page * page,loff_t pos)1532 static void unmap_buffers(struct page *page, loff_t pos)
1533 {
1534 	struct buffer_head *bh;
1535 	struct buffer_head *head;
1536 	struct buffer_head *next;
1537 	unsigned long tail_index;
1538 	unsigned long cur_index;
1539 
1540 	if (page) {
1541 		if (page_has_buffers(page)) {
1542 			tail_index = pos & (PAGE_SIZE - 1);
1543 			cur_index = 0;
1544 			head = page_buffers(page);
1545 			bh = head;
1546 			do {
1547 				next = bh->b_this_page;
1548 
1549 				/*
1550 				 * we want to unmap the buffers that contain
1551 				 * the tail, and all the buffers after it
1552 				 * (since the tail must be at the end of the
1553 				 * file).  We don't want to unmap file data
1554 				 * before the tail, since it might be dirty
1555 				 * and waiting to reach disk
1556 				 */
1557 				cur_index += bh->b_size;
1558 				if (cur_index > tail_index) {
1559 					reiserfs_unmap_buffer(bh);
1560 				}
1561 				bh = next;
1562 			} while (bh != head);
1563 		}
1564 	}
1565 }
1566 
maybe_indirect_to_direct(struct reiserfs_transaction_handle * th,struct inode * inode,struct page * page,struct treepath * path,const struct cpu_key * item_key,loff_t new_file_size,char * mode)1567 static int maybe_indirect_to_direct(struct reiserfs_transaction_handle *th,
1568 				    struct inode *inode,
1569 				    struct page *page,
1570 				    struct treepath *path,
1571 				    const struct cpu_key *item_key,
1572 				    loff_t new_file_size, char *mode)
1573 {
1574 	struct super_block *sb = inode->i_sb;
1575 	int block_size = sb->s_blocksize;
1576 	int cut_bytes;
1577 	BUG_ON(!th->t_trans_id);
1578 	BUG_ON(new_file_size != inode->i_size);
1579 
1580 	/*
1581 	 * the page being sent in could be NULL if there was an i/o error
1582 	 * reading in the last block.  The user will hit problems trying to
1583 	 * read the file, but for now we just skip the indirect2direct
1584 	 */
1585 	if (atomic_read(&inode->i_count) > 1 ||
1586 	    !tail_has_to_be_packed(inode) ||
1587 	    !page || (REISERFS_I(inode)->i_flags & i_nopack_mask)) {
1588 		/* leave tail in an unformatted node */
1589 		*mode = M_SKIP_BALANCING;
1590 		cut_bytes =
1591 		    block_size - (new_file_size & (block_size - 1));
1592 		pathrelse(path);
1593 		return cut_bytes;
1594 	}
1595 
1596 	/* Perform the conversion to a direct_item. */
1597 	return indirect2direct(th, inode, page, path, item_key,
1598 			       new_file_size, mode);
1599 }
1600 
1601 /*
1602  * we did indirect_to_direct conversion. And we have inserted direct
1603  * item successesfully, but there were no disk space to cut unfm
1604  * pointer being converted. Therefore we have to delete inserted
1605  * direct item(s)
1606  */
indirect_to_direct_roll_back(struct reiserfs_transaction_handle * th,struct inode * inode,struct treepath * path)1607 static void indirect_to_direct_roll_back(struct reiserfs_transaction_handle *th,
1608 					 struct inode *inode, struct treepath *path)
1609 {
1610 	struct cpu_key tail_key;
1611 	int tail_len;
1612 	int removed;
1613 	BUG_ON(!th->t_trans_id);
1614 
1615 	make_cpu_key(&tail_key, inode, inode->i_size + 1, TYPE_DIRECT, 4);
1616 	tail_key.key_length = 4;
1617 
1618 	tail_len =
1619 	    (cpu_key_k_offset(&tail_key) & (inode->i_sb->s_blocksize - 1)) - 1;
1620 	while (tail_len) {
1621 		/* look for the last byte of the tail */
1622 		if (search_for_position_by_key(inode->i_sb, &tail_key, path) ==
1623 		    POSITION_NOT_FOUND)
1624 			reiserfs_panic(inode->i_sb, "vs-5615",
1625 				       "found invalid item");
1626 		RFALSE(path->pos_in_item !=
1627 		       ih_item_len(tp_item_head(path)) - 1,
1628 		       "vs-5616: appended bytes found");
1629 		PATH_LAST_POSITION(path)--;
1630 
1631 		removed =
1632 		    reiserfs_delete_item(th, path, &tail_key, inode,
1633 					 NULL /*unbh not needed */ );
1634 		RFALSE(removed <= 0
1635 		       || removed > tail_len,
1636 		       "vs-5617: there was tail %d bytes, removed item length %d bytes",
1637 		       tail_len, removed);
1638 		tail_len -= removed;
1639 		set_cpu_key_k_offset(&tail_key,
1640 				     cpu_key_k_offset(&tail_key) - removed);
1641 	}
1642 	reiserfs_warning(inode->i_sb, "reiserfs-5091", "indirect_to_direct "
1643 			 "conversion has been rolled back due to "
1644 			 "lack of disk space");
1645 	mark_inode_dirty(inode);
1646 }
1647 
1648 /* (Truncate or cut entry) or delete object item. Returns < 0 on failure */
reiserfs_cut_from_item(struct reiserfs_transaction_handle * th,struct treepath * path,struct cpu_key * item_key,struct inode * inode,struct page * page,loff_t new_file_size)1649 int reiserfs_cut_from_item(struct reiserfs_transaction_handle *th,
1650 			   struct treepath *path,
1651 			   struct cpu_key *item_key,
1652 			   struct inode *inode,
1653 			   struct page *page, loff_t new_file_size)
1654 {
1655 	struct super_block *sb = inode->i_sb;
1656 	/*
1657 	 * Every function which is going to call do_balance must first
1658 	 * create a tree_balance structure.  Then it must fill up this
1659 	 * structure by using the init_tb_struct and fix_nodes functions.
1660 	 * After that we can make tree balancing.
1661 	 */
1662 	struct tree_balance s_cut_balance;
1663 	struct item_head *p_le_ih;
1664 	int cut_size = 0;	/* Amount to be cut. */
1665 	int ret_value = CARRY_ON;
1666 	int removed = 0;	/* Number of the removed unformatted nodes. */
1667 	int is_inode_locked = 0;
1668 	char mode;		/* Mode of the balance. */
1669 	int retval2 = -1;
1670 	int quota_cut_bytes;
1671 	loff_t tail_pos = 0;
1672 	int depth;
1673 
1674 	BUG_ON(!th->t_trans_id);
1675 
1676 	init_tb_struct(th, &s_cut_balance, inode->i_sb, path,
1677 		       cut_size);
1678 
1679 	/*
1680 	 * Repeat this loop until we either cut the item without needing
1681 	 * to balance, or we fix_nodes without schedule occurring
1682 	 */
1683 	while (1) {
1684 		/*
1685 		 * Determine the balance mode, position of the first byte to
1686 		 * be cut, and size to be cut.  In case of the indirect item
1687 		 * free unformatted nodes which are pointed to by the cut
1688 		 * pointers.
1689 		 */
1690 
1691 		mode =
1692 		    prepare_for_delete_or_cut(th, inode, path,
1693 					      item_key, &removed,
1694 					      &cut_size, new_file_size);
1695 		if (mode == M_CONVERT) {
1696 			/*
1697 			 * convert last unformatted node to direct item or
1698 			 * leave tail in the unformatted node
1699 			 */
1700 			RFALSE(ret_value != CARRY_ON,
1701 			       "PAP-5570: can not convert twice");
1702 
1703 			ret_value =
1704 			    maybe_indirect_to_direct(th, inode, page,
1705 						     path, item_key,
1706 						     new_file_size, &mode);
1707 			if (mode == M_SKIP_BALANCING)
1708 				/* tail has been left in the unformatted node */
1709 				return ret_value;
1710 
1711 			is_inode_locked = 1;
1712 
1713 			/*
1714 			 * removing of last unformatted node will
1715 			 * change value we have to return to truncate.
1716 			 * Save it
1717 			 */
1718 			retval2 = ret_value;
1719 
1720 			/*
1721 			 * So, we have performed the first part of the
1722 			 * conversion:
1723 			 * inserting the new direct item.  Now we are
1724 			 * removing the last unformatted node pointer.
1725 			 * Set key to search for it.
1726 			 */
1727 			set_cpu_key_k_type(item_key, TYPE_INDIRECT);
1728 			item_key->key_length = 4;
1729 			new_file_size -=
1730 			    (new_file_size & (sb->s_blocksize - 1));
1731 			tail_pos = new_file_size;
1732 			set_cpu_key_k_offset(item_key, new_file_size + 1);
1733 			if (search_for_position_by_key
1734 			    (sb, item_key,
1735 			     path) == POSITION_NOT_FOUND) {
1736 				print_block(PATH_PLAST_BUFFER(path), 3,
1737 					    PATH_LAST_POSITION(path) - 1,
1738 					    PATH_LAST_POSITION(path) + 1);
1739 				reiserfs_panic(sb, "PAP-5580", "item to "
1740 					       "convert does not exist (%K)",
1741 					       item_key);
1742 			}
1743 			continue;
1744 		}
1745 		if (cut_size == 0) {
1746 			pathrelse(path);
1747 			return 0;
1748 		}
1749 
1750 		s_cut_balance.insert_size[0] = cut_size;
1751 
1752 		ret_value = fix_nodes(mode, &s_cut_balance, NULL, NULL);
1753 		if (ret_value != REPEAT_SEARCH)
1754 			break;
1755 
1756 		PROC_INFO_INC(sb, cut_from_item_restarted);
1757 
1758 		ret_value =
1759 		    search_for_position_by_key(sb, item_key, path);
1760 		if (ret_value == POSITION_FOUND)
1761 			continue;
1762 
1763 		reiserfs_warning(sb, "PAP-5610", "item %K not found",
1764 				 item_key);
1765 		unfix_nodes(&s_cut_balance);
1766 		return (ret_value == IO_ERROR) ? -EIO : -ENOENT;
1767 	}			/* while */
1768 
1769 	/* check fix_nodes results (IO_ERROR or NO_DISK_SPACE) */
1770 	if (ret_value != CARRY_ON) {
1771 		if (is_inode_locked) {
1772 			/*
1773 			 * FIXME: this seems to be not needed: we are always
1774 			 * able to cut item
1775 			 */
1776 			indirect_to_direct_roll_back(th, inode, path);
1777 		}
1778 		if (ret_value == NO_DISK_SPACE)
1779 			reiserfs_warning(sb, "reiserfs-5092",
1780 					 "NO_DISK_SPACE");
1781 		unfix_nodes(&s_cut_balance);
1782 		return -EIO;
1783 	}
1784 
1785 	/* go ahead and perform balancing */
1786 
1787 	RFALSE(mode == M_PASTE || mode == M_INSERT, "invalid mode");
1788 
1789 	/* Calculate number of bytes that need to be cut from the item. */
1790 	quota_cut_bytes =
1791 	    (mode ==
1792 	     M_DELETE) ? ih_item_len(tp_item_head(path)) : -s_cut_balance.
1793 	    insert_size[0];
1794 	if (retval2 == -1)
1795 		ret_value = calc_deleted_bytes_number(&s_cut_balance, mode);
1796 	else
1797 		ret_value = retval2;
1798 
1799 	/*
1800 	 * For direct items, we only change the quota when deleting the last
1801 	 * item.
1802 	 */
1803 	p_le_ih = tp_item_head(s_cut_balance.tb_path);
1804 	if (!S_ISLNK(inode->i_mode) && is_direct_le_ih(p_le_ih)) {
1805 		if (mode == M_DELETE &&
1806 		    (le_ih_k_offset(p_le_ih) & (sb->s_blocksize - 1)) ==
1807 		    1) {
1808 			/* FIXME: this is to keep 3.5 happy */
1809 			REISERFS_I(inode)->i_first_direct_byte = U32_MAX;
1810 			quota_cut_bytes = sb->s_blocksize + UNFM_P_SIZE;
1811 		} else {
1812 			quota_cut_bytes = 0;
1813 		}
1814 	}
1815 #ifdef CONFIG_REISERFS_CHECK
1816 	if (is_inode_locked) {
1817 		struct item_head *le_ih =
1818 		    tp_item_head(s_cut_balance.tb_path);
1819 		/*
1820 		 * we are going to complete indirect2direct conversion. Make
1821 		 * sure, that we exactly remove last unformatted node pointer
1822 		 * of the item
1823 		 */
1824 		if (!is_indirect_le_ih(le_ih))
1825 			reiserfs_panic(sb, "vs-5652",
1826 				       "item must be indirect %h", le_ih);
1827 
1828 		if (mode == M_DELETE && ih_item_len(le_ih) != UNFM_P_SIZE)
1829 			reiserfs_panic(sb, "vs-5653", "completing "
1830 				       "indirect2direct conversion indirect "
1831 				       "item %h being deleted must be of "
1832 				       "4 byte long", le_ih);
1833 
1834 		if (mode == M_CUT
1835 		    && s_cut_balance.insert_size[0] != -UNFM_P_SIZE) {
1836 			reiserfs_panic(sb, "vs-5654", "can not complete "
1837 				       "indirect2direct conversion of %h "
1838 				       "(CUT, insert_size==%d)",
1839 				       le_ih, s_cut_balance.insert_size[0]);
1840 		}
1841 		/*
1842 		 * it would be useful to make sure, that right neighboring
1843 		 * item is direct item of this file
1844 		 */
1845 	}
1846 #endif
1847 
1848 	do_balance(&s_cut_balance, NULL, NULL, mode);
1849 	if (is_inode_locked) {
1850 		/*
1851 		 * we've done an indirect->direct conversion.  when the
1852 		 * data block was freed, it was removed from the list of
1853 		 * blocks that must be flushed before the transaction
1854 		 * commits, make sure to unmap and invalidate it
1855 		 */
1856 		unmap_buffers(page, tail_pos);
1857 		REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask;
1858 	}
1859 #ifdef REISERQUOTA_DEBUG
1860 	reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
1861 		       "reiserquota cut_from_item(): freeing %u id=%u type=%c",
1862 		       quota_cut_bytes, inode->i_uid, '?');
1863 #endif
1864 	depth = reiserfs_write_unlock_nested(sb);
1865 	dquot_free_space_nodirty(inode, quota_cut_bytes);
1866 	reiserfs_write_lock_nested(sb, depth);
1867 	return ret_value;
1868 }
1869 
truncate_directory(struct reiserfs_transaction_handle * th,struct inode * inode)1870 static void truncate_directory(struct reiserfs_transaction_handle *th,
1871 			       struct inode *inode)
1872 {
1873 	BUG_ON(!th->t_trans_id);
1874 	if (inode->i_nlink)
1875 		reiserfs_error(inode->i_sb, "vs-5655", "link count != 0");
1876 
1877 	set_le_key_k_offset(KEY_FORMAT_3_5, INODE_PKEY(inode), DOT_OFFSET);
1878 	set_le_key_k_type(KEY_FORMAT_3_5, INODE_PKEY(inode), TYPE_DIRENTRY);
1879 	reiserfs_delete_solid_item(th, inode, INODE_PKEY(inode));
1880 	reiserfs_update_sd(th, inode);
1881 	set_le_key_k_offset(KEY_FORMAT_3_5, INODE_PKEY(inode), SD_OFFSET);
1882 	set_le_key_k_type(KEY_FORMAT_3_5, INODE_PKEY(inode), TYPE_STAT_DATA);
1883 }
1884 
1885 /*
1886  * Truncate file to the new size. Note, this must be called with a
1887  * transaction already started
1888  */
reiserfs_do_truncate(struct reiserfs_transaction_handle * th,struct inode * inode,struct page * page,int update_timestamps)1889 int reiserfs_do_truncate(struct reiserfs_transaction_handle *th,
1890 			 struct inode *inode,	/* ->i_size contains new size */
1891 			 struct page *page,	/* up to date for last block */
1892 			 /*
1893 			  * when it is called by file_release to convert
1894 			  * the tail - no timestamps should be updated
1895 			  */
1896 			 int update_timestamps
1897     )
1898 {
1899 	INITIALIZE_PATH(s_search_path);	/* Path to the current object item. */
1900 	struct item_head *p_le_ih;	/* Pointer to an item header. */
1901 
1902 	/* Key to search for a previous file item. */
1903 	struct cpu_key s_item_key;
1904 	loff_t file_size,	/* Old file size. */
1905 	 new_file_size;	/* New file size. */
1906 	int deleted;		/* Number of deleted or truncated bytes. */
1907 	int retval;
1908 	int err = 0;
1909 
1910 	BUG_ON(!th->t_trans_id);
1911 	if (!
1912 	    (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1913 	     || S_ISLNK(inode->i_mode)))
1914 		return 0;
1915 
1916 	/* deletion of directory - no need to update timestamps */
1917 	if (S_ISDIR(inode->i_mode)) {
1918 		truncate_directory(th, inode);
1919 		return 0;
1920 	}
1921 
1922 	/* Get new file size. */
1923 	new_file_size = inode->i_size;
1924 
1925 	/* FIXME: note, that key type is unimportant here */
1926 	make_cpu_key(&s_item_key, inode, max_reiserfs_offset(inode),
1927 		     TYPE_DIRECT, 3);
1928 
1929 	retval =
1930 	    search_for_position_by_key(inode->i_sb, &s_item_key,
1931 				       &s_search_path);
1932 	if (retval == IO_ERROR) {
1933 		reiserfs_error(inode->i_sb, "vs-5657",
1934 			       "i/o failure occurred trying to truncate %K",
1935 			       &s_item_key);
1936 		err = -EIO;
1937 		goto out;
1938 	}
1939 	if (retval == POSITION_FOUND || retval == FILE_NOT_FOUND) {
1940 		reiserfs_error(inode->i_sb, "PAP-5660",
1941 			       "wrong result %d of search for %K", retval,
1942 			       &s_item_key);
1943 
1944 		err = -EIO;
1945 		goto out;
1946 	}
1947 
1948 	s_search_path.pos_in_item--;
1949 
1950 	/* Get real file size (total length of all file items) */
1951 	p_le_ih = tp_item_head(&s_search_path);
1952 	if (is_statdata_le_ih(p_le_ih))
1953 		file_size = 0;
1954 	else {
1955 		loff_t offset = le_ih_k_offset(p_le_ih);
1956 		int bytes =
1957 		    op_bytes_number(p_le_ih, inode->i_sb->s_blocksize);
1958 
1959 		/*
1960 		 * this may mismatch with real file size: if last direct item
1961 		 * had no padding zeros and last unformatted node had no free
1962 		 * space, this file would have this file size
1963 		 */
1964 		file_size = offset + bytes - 1;
1965 	}
1966 	/*
1967 	 * are we doing a full truncate or delete, if so
1968 	 * kick in the reada code
1969 	 */
1970 	if (new_file_size == 0)
1971 		s_search_path.reada = PATH_READA | PATH_READA_BACK;
1972 
1973 	if (file_size == 0 || file_size < new_file_size) {
1974 		goto update_and_out;
1975 	}
1976 
1977 	/* Update key to search for the last file item. */
1978 	set_cpu_key_k_offset(&s_item_key, file_size);
1979 
1980 	do {
1981 		/* Cut or delete file item. */
1982 		deleted =
1983 		    reiserfs_cut_from_item(th, &s_search_path, &s_item_key,
1984 					   inode, page, new_file_size);
1985 		if (deleted < 0) {
1986 			reiserfs_warning(inode->i_sb, "vs-5665",
1987 					 "reiserfs_cut_from_item failed");
1988 			reiserfs_check_path(&s_search_path);
1989 			return 0;
1990 		}
1991 
1992 		RFALSE(deleted > file_size,
1993 		       "PAP-5670: reiserfs_cut_from_item: too many bytes deleted: deleted %d, file_size %lu, item_key %K",
1994 		       deleted, file_size, &s_item_key);
1995 
1996 		/* Change key to search the last file item. */
1997 		file_size -= deleted;
1998 
1999 		set_cpu_key_k_offset(&s_item_key, file_size);
2000 
2001 		/*
2002 		 * While there are bytes to truncate and previous
2003 		 * file item is presented in the tree.
2004 		 */
2005 
2006 		/*
2007 		 * This loop could take a really long time, and could log
2008 		 * many more blocks than a transaction can hold.  So, we do
2009 		 * a polite journal end here, and if the transaction needs
2010 		 * ending, we make sure the file is consistent before ending
2011 		 * the current trans and starting a new one
2012 		 */
2013 		if (journal_transaction_should_end(th, 0) ||
2014 		    reiserfs_transaction_free_space(th) <= JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD) {
2015 			pathrelse(&s_search_path);
2016 
2017 			if (update_timestamps) {
2018 				inode->i_mtime = current_time(inode);
2019 				inode->i_ctime = current_time(inode);
2020 			}
2021 			reiserfs_update_sd(th, inode);
2022 
2023 			err = journal_end(th);
2024 			if (err)
2025 				goto out;
2026 			err = journal_begin(th, inode->i_sb,
2027 					    JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD + JOURNAL_PER_BALANCE_CNT * 4) ;
2028 			if (err)
2029 				goto out;
2030 			reiserfs_update_inode_transaction(inode);
2031 		}
2032 	} while (file_size > ROUND_UP(new_file_size) &&
2033 		 search_for_position_by_key(inode->i_sb, &s_item_key,
2034 					    &s_search_path) == POSITION_FOUND);
2035 
2036 	RFALSE(file_size > ROUND_UP(new_file_size),
2037 	       "PAP-5680: truncate did not finish: new_file_size %lld, current %lld, oid %d",
2038 	       new_file_size, file_size, s_item_key.on_disk_key.k_objectid);
2039 
2040 update_and_out:
2041 	if (update_timestamps) {
2042 		/* this is truncate, not file closing */
2043 		inode->i_mtime = current_time(inode);
2044 		inode->i_ctime = current_time(inode);
2045 	}
2046 	reiserfs_update_sd(th, inode);
2047 
2048 out:
2049 	pathrelse(&s_search_path);
2050 	return err;
2051 }
2052 
2053 #ifdef CONFIG_REISERFS_CHECK
2054 /* this makes sure, that we __append__, not overwrite or add holes */
check_research_for_paste(struct treepath * path,const struct cpu_key * key)2055 static void check_research_for_paste(struct treepath *path,
2056 				     const struct cpu_key *key)
2057 {
2058 	struct item_head *found_ih = tp_item_head(path);
2059 
2060 	if (is_direct_le_ih(found_ih)) {
2061 		if (le_ih_k_offset(found_ih) +
2062 		    op_bytes_number(found_ih,
2063 				    get_last_bh(path)->b_size) !=
2064 		    cpu_key_k_offset(key)
2065 		    || op_bytes_number(found_ih,
2066 				       get_last_bh(path)->b_size) !=
2067 		    pos_in_item(path))
2068 			reiserfs_panic(NULL, "PAP-5720", "found direct item "
2069 				       "%h or position (%d) does not match "
2070 				       "to key %K", found_ih,
2071 				       pos_in_item(path), key);
2072 	}
2073 	if (is_indirect_le_ih(found_ih)) {
2074 		if (le_ih_k_offset(found_ih) +
2075 		    op_bytes_number(found_ih,
2076 				    get_last_bh(path)->b_size) !=
2077 		    cpu_key_k_offset(key)
2078 		    || I_UNFM_NUM(found_ih) != pos_in_item(path)
2079 		    || get_ih_free_space(found_ih) != 0)
2080 			reiserfs_panic(NULL, "PAP-5730", "found indirect "
2081 				       "item (%h) or position (%d) does not "
2082 				       "match to key (%K)",
2083 				       found_ih, pos_in_item(path), key);
2084 	}
2085 }
2086 #endif				/* config reiserfs check */
2087 
2088 /*
2089  * Paste bytes to the existing item.
2090  * Returns bytes number pasted into the item.
2091  */
reiserfs_paste_into_item(struct reiserfs_transaction_handle * th,struct treepath * search_path,const struct cpu_key * key,struct inode * inode,const char * body,int pasted_size)2092 int reiserfs_paste_into_item(struct reiserfs_transaction_handle *th,
2093 			     /* Path to the pasted item. */
2094 			     struct treepath *search_path,
2095 			     /* Key to search for the needed item. */
2096 			     const struct cpu_key *key,
2097 			     /* Inode item belongs to */
2098 			     struct inode *inode,
2099 			     /* Pointer to the bytes to paste. */
2100 			     const char *body,
2101 			     /* Size of pasted bytes. */
2102 			     int pasted_size)
2103 {
2104 	struct super_block *sb = inode->i_sb;
2105 	struct tree_balance s_paste_balance;
2106 	int retval;
2107 	int fs_gen;
2108 	int depth;
2109 
2110 	BUG_ON(!th->t_trans_id);
2111 
2112 	fs_gen = get_generation(inode->i_sb);
2113 
2114 #ifdef REISERQUOTA_DEBUG
2115 	reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
2116 		       "reiserquota paste_into_item(): allocating %u id=%u type=%c",
2117 		       pasted_size, inode->i_uid,
2118 		       key2type(&key->on_disk_key));
2119 #endif
2120 
2121 	depth = reiserfs_write_unlock_nested(sb);
2122 	retval = dquot_alloc_space_nodirty(inode, pasted_size);
2123 	reiserfs_write_lock_nested(sb, depth);
2124 	if (retval) {
2125 		pathrelse(search_path);
2126 		return retval;
2127 	}
2128 	init_tb_struct(th, &s_paste_balance, th->t_super, search_path,
2129 		       pasted_size);
2130 #ifdef DISPLACE_NEW_PACKING_LOCALITIES
2131 	s_paste_balance.key = key->on_disk_key;
2132 #endif
2133 
2134 	/* DQUOT_* can schedule, must check before the fix_nodes */
2135 	if (fs_changed(fs_gen, inode->i_sb)) {
2136 		goto search_again;
2137 	}
2138 
2139 	while ((retval =
2140 		fix_nodes(M_PASTE, &s_paste_balance, NULL,
2141 			  body)) == REPEAT_SEARCH) {
2142 search_again:
2143 		/* file system changed while we were in the fix_nodes */
2144 		PROC_INFO_INC(th->t_super, paste_into_item_restarted);
2145 		retval =
2146 		    search_for_position_by_key(th->t_super, key,
2147 					       search_path);
2148 		if (retval == IO_ERROR) {
2149 			retval = -EIO;
2150 			goto error_out;
2151 		}
2152 		if (retval == POSITION_FOUND) {
2153 			reiserfs_warning(inode->i_sb, "PAP-5710",
2154 					 "entry or pasted byte (%K) exists",
2155 					 key);
2156 			retval = -EEXIST;
2157 			goto error_out;
2158 		}
2159 #ifdef CONFIG_REISERFS_CHECK
2160 		check_research_for_paste(search_path, key);
2161 #endif
2162 	}
2163 
2164 	/*
2165 	 * Perform balancing after all resources are collected by fix_nodes,
2166 	 * and accessing them will not risk triggering schedule.
2167 	 */
2168 	if (retval == CARRY_ON) {
2169 		do_balance(&s_paste_balance, NULL /*ih */ , body, M_PASTE);
2170 		return 0;
2171 	}
2172 	retval = (retval == NO_DISK_SPACE) ? -ENOSPC : -EIO;
2173 error_out:
2174 	/* this also releases the path */
2175 	unfix_nodes(&s_paste_balance);
2176 #ifdef REISERQUOTA_DEBUG
2177 	reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
2178 		       "reiserquota paste_into_item(): freeing %u id=%u type=%c",
2179 		       pasted_size, inode->i_uid,
2180 		       key2type(&key->on_disk_key));
2181 #endif
2182 	depth = reiserfs_write_unlock_nested(sb);
2183 	dquot_free_space_nodirty(inode, pasted_size);
2184 	reiserfs_write_lock_nested(sb, depth);
2185 	return retval;
2186 }
2187 
2188 /*
2189  * Insert new item into the buffer at the path.
2190  * th   - active transaction handle
2191  * path - path to the inserted item
2192  * ih   - pointer to the item header to insert
2193  * body - pointer to the bytes to insert
2194  */
reiserfs_insert_item(struct reiserfs_transaction_handle * th,struct treepath * path,const struct cpu_key * key,struct item_head * ih,struct inode * inode,const char * body)2195 int reiserfs_insert_item(struct reiserfs_transaction_handle *th,
2196 			 struct treepath *path, const struct cpu_key *key,
2197 			 struct item_head *ih, struct inode *inode,
2198 			 const char *body)
2199 {
2200 	struct tree_balance s_ins_balance;
2201 	int retval;
2202 	int fs_gen = 0;
2203 	int quota_bytes = 0;
2204 
2205 	BUG_ON(!th->t_trans_id);
2206 
2207 	if (inode) {		/* Do we count quotas for item? */
2208 		int depth;
2209 		fs_gen = get_generation(inode->i_sb);
2210 		quota_bytes = ih_item_len(ih);
2211 
2212 		/*
2213 		 * hack so the quota code doesn't have to guess
2214 		 * if the file has a tail, links are always tails,
2215 		 * so there's no guessing needed
2216 		 */
2217 		if (!S_ISLNK(inode->i_mode) && is_direct_le_ih(ih))
2218 			quota_bytes = inode->i_sb->s_blocksize + UNFM_P_SIZE;
2219 #ifdef REISERQUOTA_DEBUG
2220 		reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
2221 			       "reiserquota insert_item(): allocating %u id=%u type=%c",
2222 			       quota_bytes, inode->i_uid, head2type(ih));
2223 #endif
2224 		/*
2225 		 * We can't dirty inode here. It would be immediately
2226 		 * written but appropriate stat item isn't inserted yet...
2227 		 */
2228 		depth = reiserfs_write_unlock_nested(inode->i_sb);
2229 		retval = dquot_alloc_space_nodirty(inode, quota_bytes);
2230 		reiserfs_write_lock_nested(inode->i_sb, depth);
2231 		if (retval) {
2232 			pathrelse(path);
2233 			return retval;
2234 		}
2235 	}
2236 	init_tb_struct(th, &s_ins_balance, th->t_super, path,
2237 		       IH_SIZE + ih_item_len(ih));
2238 #ifdef DISPLACE_NEW_PACKING_LOCALITIES
2239 	s_ins_balance.key = key->on_disk_key;
2240 #endif
2241 	/*
2242 	 * DQUOT_* can schedule, must check to be sure calling
2243 	 * fix_nodes is safe
2244 	 */
2245 	if (inode && fs_changed(fs_gen, inode->i_sb)) {
2246 		goto search_again;
2247 	}
2248 
2249 	while ((retval =
2250 		fix_nodes(M_INSERT, &s_ins_balance, ih,
2251 			  body)) == REPEAT_SEARCH) {
2252 search_again:
2253 		/* file system changed while we were in the fix_nodes */
2254 		PROC_INFO_INC(th->t_super, insert_item_restarted);
2255 		retval = search_item(th->t_super, key, path);
2256 		if (retval == IO_ERROR) {
2257 			retval = -EIO;
2258 			goto error_out;
2259 		}
2260 		if (retval == ITEM_FOUND) {
2261 			reiserfs_warning(th->t_super, "PAP-5760",
2262 					 "key %K already exists in the tree",
2263 					 key);
2264 			retval = -EEXIST;
2265 			goto error_out;
2266 		}
2267 	}
2268 
2269 	/* make balancing after all resources will be collected at a time */
2270 	if (retval == CARRY_ON) {
2271 		do_balance(&s_ins_balance, ih, body, M_INSERT);
2272 		return 0;
2273 	}
2274 
2275 	retval = (retval == NO_DISK_SPACE) ? -ENOSPC : -EIO;
2276 error_out:
2277 	/* also releases the path */
2278 	unfix_nodes(&s_ins_balance);
2279 #ifdef REISERQUOTA_DEBUG
2280 	if (inode)
2281 		reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
2282 		       "reiserquota insert_item(): freeing %u id=%u type=%c",
2283 		       quota_bytes, inode->i_uid, head2type(ih));
2284 #endif
2285 	if (inode) {
2286 		int depth = reiserfs_write_unlock_nested(inode->i_sb);
2287 		dquot_free_space_nodirty(inode, quota_bytes);
2288 		reiserfs_write_lock_nested(inode->i_sb, depth);
2289 	}
2290 	return retval;
2291 }
2292