xref: /openbmc/linux/fs/gfs2/dir.c (revision 24b1944f)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 /*
11  * Implements Extendible Hashing as described in:
12  *   "Extendible Hashing" by Fagin, et al in
13  *     __ACM Trans. on Database Systems__, Sept 1979.
14  *
15  *
16  * Here's the layout of dirents which is essentially the same as that of ext2
17  * within a single block. The field de_name_len is the number of bytes
18  * actually required for the name (no null terminator). The field de_rec_len
19  * is the number of bytes allocated to the dirent. The offset of the next
20  * dirent in the block is (dirent + dirent->de_rec_len). When a dirent is
21  * deleted, the preceding dirent inherits its allocated space, ie
22  * prev->de_rec_len += deleted->de_rec_len. Since the next dirent is obtained
23  * by adding de_rec_len to the current dirent, this essentially causes the
24  * deleted dirent to get jumped over when iterating through all the dirents.
25  *
26  * When deleting the first dirent in a block, there is no previous dirent so
27  * the field de_ino is set to zero to designate it as deleted. When allocating
28  * a dirent, gfs2_dirent_alloc iterates through the dirents in a block. If the
29  * first dirent has (de_ino == 0) and de_rec_len is large enough, this first
30  * dirent is allocated. Otherwise it must go through all the 'used' dirents
31  * searching for one in which the amount of total space minus the amount of
32  * used space will provide enough space for the new dirent.
33  *
34  * There are two types of blocks in which dirents reside. In a stuffed dinode,
35  * the dirents begin at offset sizeof(struct gfs2_dinode) from the beginning of
36  * the block.  In leaves, they begin at offset sizeof(struct gfs2_leaf) from the
37  * beginning of the leaf block. The dirents reside in leaves when
38  *
39  * dip->i_diskflags & GFS2_DIF_EXHASH is true
40  *
41  * Otherwise, the dirents are "linear", within a single stuffed dinode block.
42  *
43  * When the dirents are in leaves, the actual contents of the directory file are
44  * used as an array of 64-bit block pointers pointing to the leaf blocks. The
45  * dirents are NOT in the directory file itself. There can be more than one
46  * block pointer in the array that points to the same leaf. In fact, when a
47  * directory is first converted from linear to exhash, all of the pointers
48  * point to the same leaf.
49  *
50  * When a leaf is completely full, the size of the hash table can be
51  * doubled unless it is already at the maximum size which is hard coded into
52  * GFS2_DIR_MAX_DEPTH. After that, leaves are chained together in a linked list,
53  * but never before the maximum hash table size has been reached.
54  */
55 
56 #include <linux/slab.h>
57 #include <linux/spinlock.h>
58 #include <linux/buffer_head.h>
59 #include <linux/sort.h>
60 #include <linux/gfs2_ondisk.h>
61 #include <linux/crc32.h>
62 #include <linux/vmalloc.h>
63 
64 #include "gfs2.h"
65 #include "incore.h"
66 #include "dir.h"
67 #include "glock.h"
68 #include "inode.h"
69 #include "meta_io.h"
70 #include "quota.h"
71 #include "rgrp.h"
72 #include "trans.h"
73 #include "bmap.h"
74 #include "util.h"
75 
76 #define IS_LEAF     1 /* Hashed (leaf) directory */
77 #define IS_DINODE   2 /* Linear (stuffed dinode block) directory */
78 
79 #define MAX_RA_BLOCKS 32 /* max read-ahead blocks */
80 
81 #define gfs2_disk_hash2offset(h) (((u64)(h)) >> 1)
82 #define gfs2_dir_offset2hash(p) ((u32)(((u64)(p)) << 1))
83 
84 struct qstr gfs2_qdot __read_mostly;
85 struct qstr gfs2_qdotdot __read_mostly;
86 
87 typedef int (*gfs2_dscan_t)(const struct gfs2_dirent *dent,
88 			    const struct qstr *name, void *opaque);
89 
90 int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
91 			    struct buffer_head **bhp)
92 {
93 	struct buffer_head *bh;
94 
95 	bh = gfs2_meta_new(ip->i_gl, block);
96 	gfs2_trans_add_meta(ip->i_gl, bh);
97 	gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD);
98 	gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
99 	*bhp = bh;
100 	return 0;
101 }
102 
103 static int gfs2_dir_get_existing_buffer(struct gfs2_inode *ip, u64 block,
104 					struct buffer_head **bhp)
105 {
106 	struct buffer_head *bh;
107 	int error;
108 
109 	error = gfs2_meta_read(ip->i_gl, block, DIO_WAIT, &bh);
110 	if (error)
111 		return error;
112 	if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_JD)) {
113 		brelse(bh);
114 		return -EIO;
115 	}
116 	*bhp = bh;
117 	return 0;
118 }
119 
120 static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf,
121 				  unsigned int offset, unsigned int size)
122 {
123 	struct buffer_head *dibh;
124 	int error;
125 
126 	error = gfs2_meta_inode_buffer(ip, &dibh);
127 	if (error)
128 		return error;
129 
130 	gfs2_trans_add_meta(ip->i_gl, dibh);
131 	memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
132 	if (ip->i_inode.i_size < offset + size)
133 		i_size_write(&ip->i_inode, offset + size);
134 	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
135 	gfs2_dinode_out(ip, dibh->b_data);
136 
137 	brelse(dibh);
138 
139 	return size;
140 }
141 
142 
143 
144 /**
145  * gfs2_dir_write_data - Write directory information to the inode
146  * @ip: The GFS2 inode
147  * @buf: The buffer containing information to be written
148  * @offset: The file offset to start writing at
149  * @size: The amount of data to write
150  *
151  * Returns: The number of bytes correctly written or error code
152  */
153 static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
154 			       u64 offset, unsigned int size)
155 {
156 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
157 	struct buffer_head *dibh;
158 	u64 lblock, dblock;
159 	u32 extlen = 0;
160 	unsigned int o;
161 	int copied = 0;
162 	int error = 0;
163 	int new = 0;
164 
165 	if (!size)
166 		return 0;
167 
168 	if (gfs2_is_stuffed(ip) &&
169 	    offset + size <= sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
170 		return gfs2_dir_write_stuffed(ip, buf, (unsigned int)offset,
171 					      size);
172 
173 	if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
174 		return -EINVAL;
175 
176 	if (gfs2_is_stuffed(ip)) {
177 		error = gfs2_unstuff_dinode(ip, NULL);
178 		if (error)
179 			return error;
180 	}
181 
182 	lblock = offset;
183 	o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
184 
185 	while (copied < size) {
186 		unsigned int amount;
187 		struct buffer_head *bh;
188 
189 		amount = size - copied;
190 		if (amount > sdp->sd_sb.sb_bsize - o)
191 			amount = sdp->sd_sb.sb_bsize - o;
192 
193 		if (!extlen) {
194 			new = 1;
195 			error = gfs2_extent_map(&ip->i_inode, lblock, &new,
196 						&dblock, &extlen);
197 			if (error)
198 				goto fail;
199 			error = -EIO;
200 			if (gfs2_assert_withdraw(sdp, dblock))
201 				goto fail;
202 		}
203 
204 		if (amount == sdp->sd_jbsize || new)
205 			error = gfs2_dir_get_new_buffer(ip, dblock, &bh);
206 		else
207 			error = gfs2_dir_get_existing_buffer(ip, dblock, &bh);
208 
209 		if (error)
210 			goto fail;
211 
212 		gfs2_trans_add_meta(ip->i_gl, bh);
213 		memcpy(bh->b_data + o, buf, amount);
214 		brelse(bh);
215 
216 		buf += amount;
217 		copied += amount;
218 		lblock++;
219 		dblock++;
220 		extlen--;
221 
222 		o = sizeof(struct gfs2_meta_header);
223 	}
224 
225 out:
226 	error = gfs2_meta_inode_buffer(ip, &dibh);
227 	if (error)
228 		return error;
229 
230 	if (ip->i_inode.i_size < offset + copied)
231 		i_size_write(&ip->i_inode, offset + copied);
232 	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
233 
234 	gfs2_trans_add_meta(ip->i_gl, dibh);
235 	gfs2_dinode_out(ip, dibh->b_data);
236 	brelse(dibh);
237 
238 	return copied;
239 fail:
240 	if (copied)
241 		goto out;
242 	return error;
243 }
244 
245 static int gfs2_dir_read_stuffed(struct gfs2_inode *ip, __be64 *buf,
246 				 unsigned int size)
247 {
248 	struct buffer_head *dibh;
249 	int error;
250 
251 	error = gfs2_meta_inode_buffer(ip, &dibh);
252 	if (!error) {
253 		memcpy(buf, dibh->b_data + sizeof(struct gfs2_dinode), size);
254 		brelse(dibh);
255 	}
256 
257 	return (error) ? error : size;
258 }
259 
260 
261 /**
262  * gfs2_dir_read_data - Read a data from a directory inode
263  * @ip: The GFS2 Inode
264  * @buf: The buffer to place result into
265  * @size: Amount of data to transfer
266  *
267  * Returns: The amount of data actually copied or the error
268  */
269 static int gfs2_dir_read_data(struct gfs2_inode *ip, __be64 *buf,
270 			      unsigned int size)
271 {
272 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
273 	u64 lblock, dblock;
274 	u32 extlen = 0;
275 	unsigned int o;
276 	int copied = 0;
277 	int error = 0;
278 
279 	if (gfs2_is_stuffed(ip))
280 		return gfs2_dir_read_stuffed(ip, buf, size);
281 
282 	if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
283 		return -EINVAL;
284 
285 	lblock = 0;
286 	o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
287 
288 	while (copied < size) {
289 		unsigned int amount;
290 		struct buffer_head *bh;
291 		int new;
292 
293 		amount = size - copied;
294 		if (amount > sdp->sd_sb.sb_bsize - o)
295 			amount = sdp->sd_sb.sb_bsize - o;
296 
297 		if (!extlen) {
298 			new = 0;
299 			error = gfs2_extent_map(&ip->i_inode, lblock, &new,
300 						&dblock, &extlen);
301 			if (error || !dblock)
302 				goto fail;
303 			BUG_ON(extlen < 1);
304 			bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
305 		} else {
306 			error = gfs2_meta_read(ip->i_gl, dblock, DIO_WAIT, &bh);
307 			if (error)
308 				goto fail;
309 		}
310 		error = gfs2_metatype_check(sdp, bh, GFS2_METATYPE_JD);
311 		if (error) {
312 			brelse(bh);
313 			goto fail;
314 		}
315 		dblock++;
316 		extlen--;
317 		memcpy(buf, bh->b_data + o, amount);
318 		brelse(bh);
319 		buf += (amount/sizeof(__be64));
320 		copied += amount;
321 		lblock++;
322 		o = sizeof(struct gfs2_meta_header);
323 	}
324 
325 	return copied;
326 fail:
327 	return (copied) ? copied : error;
328 }
329 
330 /**
331  * gfs2_dir_get_hash_table - Get pointer to the dir hash table
332  * @ip: The inode in question
333  *
334  * Returns: The hash table or an error
335  */
336 
337 static __be64 *gfs2_dir_get_hash_table(struct gfs2_inode *ip)
338 {
339 	struct inode *inode = &ip->i_inode;
340 	int ret;
341 	u32 hsize;
342 	__be64 *hc;
343 
344 	BUG_ON(!(ip->i_diskflags & GFS2_DIF_EXHASH));
345 
346 	hc = ip->i_hash_cache;
347 	if (hc)
348 		return hc;
349 
350 	hsize = 1 << ip->i_depth;
351 	hsize *= sizeof(__be64);
352 	if (hsize != i_size_read(&ip->i_inode)) {
353 		gfs2_consist_inode(ip);
354 		return ERR_PTR(-EIO);
355 	}
356 
357 	hc = kmalloc(hsize, GFP_NOFS | __GFP_NOWARN);
358 	if (hc == NULL)
359 		hc = __vmalloc(hsize, GFP_NOFS, PAGE_KERNEL);
360 
361 	if (hc == NULL)
362 		return ERR_PTR(-ENOMEM);
363 
364 	ret = gfs2_dir_read_data(ip, hc, hsize);
365 	if (ret < 0) {
366 		if (is_vmalloc_addr(hc))
367 			vfree(hc);
368 		else
369 			kfree(hc);
370 		return ERR_PTR(ret);
371 	}
372 
373 	spin_lock(&inode->i_lock);
374 	if (ip->i_hash_cache) {
375 		if (is_vmalloc_addr(hc))
376 			vfree(hc);
377 		else
378 			kfree(hc);
379 	} else {
380 		ip->i_hash_cache = hc;
381 	}
382 	spin_unlock(&inode->i_lock);
383 
384 	return ip->i_hash_cache;
385 }
386 
387 /**
388  * gfs2_dir_hash_inval - Invalidate dir hash
389  * @ip: The directory inode
390  *
391  * Must be called with an exclusive glock, or during glock invalidation.
392  */
393 void gfs2_dir_hash_inval(struct gfs2_inode *ip)
394 {
395 	__be64 *hc = ip->i_hash_cache;
396 	ip->i_hash_cache = NULL;
397 	if (is_vmalloc_addr(hc))
398 		vfree(hc);
399 	else
400 		kfree(hc);
401 }
402 
403 static inline int gfs2_dirent_sentinel(const struct gfs2_dirent *dent)
404 {
405 	return dent->de_inum.no_addr == 0 || dent->de_inum.no_formal_ino == 0;
406 }
407 
408 static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent,
409 				     const struct qstr *name, int ret)
410 {
411 	if (!gfs2_dirent_sentinel(dent) &&
412 	    be32_to_cpu(dent->de_hash) == name->hash &&
413 	    be16_to_cpu(dent->de_name_len) == name->len &&
414 	    memcmp(dent+1, name->name, name->len) == 0)
415 		return ret;
416 	return 0;
417 }
418 
419 static int gfs2_dirent_find(const struct gfs2_dirent *dent,
420 			    const struct qstr *name,
421 			    void *opaque)
422 {
423 	return __gfs2_dirent_find(dent, name, 1);
424 }
425 
426 static int gfs2_dirent_prev(const struct gfs2_dirent *dent,
427 			    const struct qstr *name,
428 			    void *opaque)
429 {
430 	return __gfs2_dirent_find(dent, name, 2);
431 }
432 
433 /*
434  * name->name holds ptr to start of block.
435  * name->len holds size of block.
436  */
437 static int gfs2_dirent_last(const struct gfs2_dirent *dent,
438 			    const struct qstr *name,
439 			    void *opaque)
440 {
441 	const char *start = name->name;
442 	const char *end = (const char *)dent + be16_to_cpu(dent->de_rec_len);
443 	if (name->len == (end - start))
444 		return 1;
445 	return 0;
446 }
447 
448 static int gfs2_dirent_find_space(const struct gfs2_dirent *dent,
449 				  const struct qstr *name,
450 				  void *opaque)
451 {
452 	unsigned required = GFS2_DIRENT_SIZE(name->len);
453 	unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
454 	unsigned totlen = be16_to_cpu(dent->de_rec_len);
455 
456 	if (gfs2_dirent_sentinel(dent))
457 		actual = 0;
458 	if (totlen - actual >= required)
459 		return 1;
460 	return 0;
461 }
462 
463 struct dirent_gather {
464 	const struct gfs2_dirent **pdent;
465 	unsigned offset;
466 };
467 
468 static int gfs2_dirent_gather(const struct gfs2_dirent *dent,
469 			      const struct qstr *name,
470 			      void *opaque)
471 {
472 	struct dirent_gather *g = opaque;
473 	if (!gfs2_dirent_sentinel(dent)) {
474 		g->pdent[g->offset++] = dent;
475 	}
476 	return 0;
477 }
478 
479 /*
480  * Other possible things to check:
481  * - Inode located within filesystem size (and on valid block)
482  * - Valid directory entry type
483  * Not sure how heavy-weight we want to make this... could also check
484  * hash is correct for example, but that would take a lot of extra time.
485  * For now the most important thing is to check that the various sizes
486  * are correct.
487  */
488 static int gfs2_check_dirent(struct gfs2_dirent *dent, unsigned int offset,
489 			     unsigned int size, unsigned int len, int first)
490 {
491 	const char *msg = "gfs2_dirent too small";
492 	if (unlikely(size < sizeof(struct gfs2_dirent)))
493 		goto error;
494 	msg = "gfs2_dirent misaligned";
495 	if (unlikely(offset & 0x7))
496 		goto error;
497 	msg = "gfs2_dirent points beyond end of block";
498 	if (unlikely(offset + size > len))
499 		goto error;
500 	msg = "zero inode number";
501 	if (unlikely(!first && gfs2_dirent_sentinel(dent)))
502 		goto error;
503 	msg = "name length is greater than space in dirent";
504 	if (!gfs2_dirent_sentinel(dent) &&
505 	    unlikely(sizeof(struct gfs2_dirent)+be16_to_cpu(dent->de_name_len) >
506 		     size))
507 		goto error;
508 	return 0;
509 error:
510 	printk(KERN_WARNING "gfs2_check_dirent: %s (%s)\n", msg,
511 	       first ? "first in block" : "not first in block");
512 	return -EIO;
513 }
514 
515 static int gfs2_dirent_offset(const void *buf)
516 {
517 	const struct gfs2_meta_header *h = buf;
518 	int offset;
519 
520 	BUG_ON(buf == NULL);
521 
522 	switch(be32_to_cpu(h->mh_type)) {
523 	case GFS2_METATYPE_LF:
524 		offset = sizeof(struct gfs2_leaf);
525 		break;
526 	case GFS2_METATYPE_DI:
527 		offset = sizeof(struct gfs2_dinode);
528 		break;
529 	default:
530 		goto wrong_type;
531 	}
532 	return offset;
533 wrong_type:
534 	printk(KERN_WARNING "gfs2_scan_dirent: wrong block type %u\n",
535 	       be32_to_cpu(h->mh_type));
536 	return -1;
537 }
538 
539 static struct gfs2_dirent *gfs2_dirent_scan(struct inode *inode, void *buf,
540 					    unsigned int len, gfs2_dscan_t scan,
541 					    const struct qstr *name,
542 					    void *opaque)
543 {
544 	struct gfs2_dirent *dent, *prev;
545 	unsigned offset;
546 	unsigned size;
547 	int ret = 0;
548 
549 	ret = gfs2_dirent_offset(buf);
550 	if (ret < 0)
551 		goto consist_inode;
552 
553 	offset = ret;
554 	prev = NULL;
555 	dent = buf + offset;
556 	size = be16_to_cpu(dent->de_rec_len);
557 	if (gfs2_check_dirent(dent, offset, size, len, 1))
558 		goto consist_inode;
559 	do {
560 		ret = scan(dent, name, opaque);
561 		if (ret)
562 			break;
563 		offset += size;
564 		if (offset == len)
565 			break;
566 		prev = dent;
567 		dent = buf + offset;
568 		size = be16_to_cpu(dent->de_rec_len);
569 		if (gfs2_check_dirent(dent, offset, size, len, 0))
570 			goto consist_inode;
571 	} while(1);
572 
573 	switch(ret) {
574 	case 0:
575 		return NULL;
576 	case 1:
577 		return dent;
578 	case 2:
579 		return prev ? prev : dent;
580 	default:
581 		BUG_ON(ret > 0);
582 		return ERR_PTR(ret);
583 	}
584 
585 consist_inode:
586 	gfs2_consist_inode(GFS2_I(inode));
587 	return ERR_PTR(-EIO);
588 }
589 
590 static int dirent_check_reclen(struct gfs2_inode *dip,
591 			       const struct gfs2_dirent *d, const void *end_p)
592 {
593 	const void *ptr = d;
594 	u16 rec_len = be16_to_cpu(d->de_rec_len);
595 
596 	if (unlikely(rec_len < sizeof(struct gfs2_dirent)))
597 		goto broken;
598 	ptr += rec_len;
599 	if (ptr < end_p)
600 		return rec_len;
601 	if (ptr == end_p)
602 		return -ENOENT;
603 broken:
604 	gfs2_consist_inode(dip);
605 	return -EIO;
606 }
607 
608 /**
609  * dirent_next - Next dirent
610  * @dip: the directory
611  * @bh: The buffer
612  * @dent: Pointer to list of dirents
613  *
614  * Returns: 0 on success, error code otherwise
615  */
616 
617 static int dirent_next(struct gfs2_inode *dip, struct buffer_head *bh,
618 		       struct gfs2_dirent **dent)
619 {
620 	struct gfs2_dirent *cur = *dent, *tmp;
621 	char *bh_end = bh->b_data + bh->b_size;
622 	int ret;
623 
624 	ret = dirent_check_reclen(dip, cur, bh_end);
625 	if (ret < 0)
626 		return ret;
627 
628 	tmp = (void *)cur + ret;
629 	ret = dirent_check_reclen(dip, tmp, bh_end);
630 	if (ret == -EIO)
631 		return ret;
632 
633         /* Only the first dent could ever have de_inum.no_addr == 0 */
634 	if (gfs2_dirent_sentinel(tmp)) {
635 		gfs2_consist_inode(dip);
636 		return -EIO;
637 	}
638 
639 	*dent = tmp;
640 	return 0;
641 }
642 
643 /**
644  * dirent_del - Delete a dirent
645  * @dip: The GFS2 inode
646  * @bh: The buffer
647  * @prev: The previous dirent
648  * @cur: The current dirent
649  *
650  */
651 
652 static void dirent_del(struct gfs2_inode *dip, struct buffer_head *bh,
653 		       struct gfs2_dirent *prev, struct gfs2_dirent *cur)
654 {
655 	u16 cur_rec_len, prev_rec_len;
656 
657 	if (gfs2_dirent_sentinel(cur)) {
658 		gfs2_consist_inode(dip);
659 		return;
660 	}
661 
662 	gfs2_trans_add_meta(dip->i_gl, bh);
663 
664 	/* If there is no prev entry, this is the first entry in the block.
665 	   The de_rec_len is already as big as it needs to be.  Just zero
666 	   out the inode number and return.  */
667 
668 	if (!prev) {
669 		cur->de_inum.no_addr = 0;
670 		cur->de_inum.no_formal_ino = 0;
671 		return;
672 	}
673 
674 	/*  Combine this dentry with the previous one.  */
675 
676 	prev_rec_len = be16_to_cpu(prev->de_rec_len);
677 	cur_rec_len = be16_to_cpu(cur->de_rec_len);
678 
679 	if ((char *)prev + prev_rec_len != (char *)cur)
680 		gfs2_consist_inode(dip);
681 	if ((char *)cur + cur_rec_len > bh->b_data + bh->b_size)
682 		gfs2_consist_inode(dip);
683 
684 	prev_rec_len += cur_rec_len;
685 	prev->de_rec_len = cpu_to_be16(prev_rec_len);
686 }
687 
688 /*
689  * Takes a dent from which to grab space as an argument. Returns the
690  * newly created dent.
691  */
692 static struct gfs2_dirent *gfs2_init_dirent(struct inode *inode,
693 					    struct gfs2_dirent *dent,
694 					    const struct qstr *name,
695 					    struct buffer_head *bh)
696 {
697 	struct gfs2_inode *ip = GFS2_I(inode);
698 	struct gfs2_dirent *ndent;
699 	unsigned offset = 0, totlen;
700 
701 	if (!gfs2_dirent_sentinel(dent))
702 		offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
703 	totlen = be16_to_cpu(dent->de_rec_len);
704 	BUG_ON(offset + name->len > totlen);
705 	gfs2_trans_add_meta(ip->i_gl, bh);
706 	ndent = (struct gfs2_dirent *)((char *)dent + offset);
707 	dent->de_rec_len = cpu_to_be16(offset);
708 	gfs2_qstr2dirent(name, totlen - offset, ndent);
709 	return ndent;
710 }
711 
712 static struct gfs2_dirent *gfs2_dirent_alloc(struct inode *inode,
713 					     struct buffer_head *bh,
714 					     const struct qstr *name)
715 {
716 	struct gfs2_dirent *dent;
717 	dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
718 				gfs2_dirent_find_space, name, NULL);
719 	if (!dent || IS_ERR(dent))
720 		return dent;
721 	return gfs2_init_dirent(inode, dent, name, bh);
722 }
723 
724 static int get_leaf(struct gfs2_inode *dip, u64 leaf_no,
725 		    struct buffer_head **bhp)
726 {
727 	int error;
728 
729 	error = gfs2_meta_read(dip->i_gl, leaf_no, DIO_WAIT, bhp);
730 	if (!error && gfs2_metatype_check(GFS2_SB(&dip->i_inode), *bhp, GFS2_METATYPE_LF)) {
731 		/* printk(KERN_INFO "block num=%llu\n", leaf_no); */
732 		error = -EIO;
733 	}
734 
735 	return error;
736 }
737 
738 /**
739  * get_leaf_nr - Get a leaf number associated with the index
740  * @dip: The GFS2 inode
741  * @index:
742  * @leaf_out:
743  *
744  * Returns: 0 on success, error code otherwise
745  */
746 
747 static int get_leaf_nr(struct gfs2_inode *dip, u32 index,
748 		       u64 *leaf_out)
749 {
750 	__be64 *hash;
751 
752 	hash = gfs2_dir_get_hash_table(dip);
753 	if (IS_ERR(hash))
754 		return PTR_ERR(hash);
755 	*leaf_out = be64_to_cpu(*(hash + index));
756 	return 0;
757 }
758 
759 static int get_first_leaf(struct gfs2_inode *dip, u32 index,
760 			  struct buffer_head **bh_out)
761 {
762 	u64 leaf_no;
763 	int error;
764 
765 	error = get_leaf_nr(dip, index, &leaf_no);
766 	if (!error)
767 		error = get_leaf(dip, leaf_no, bh_out);
768 
769 	return error;
770 }
771 
772 static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
773 					      const struct qstr *name,
774 					      gfs2_dscan_t scan,
775 					      struct buffer_head **pbh)
776 {
777 	struct buffer_head *bh;
778 	struct gfs2_dirent *dent;
779 	struct gfs2_inode *ip = GFS2_I(inode);
780 	int error;
781 
782 	if (ip->i_diskflags & GFS2_DIF_EXHASH) {
783 		struct gfs2_leaf *leaf;
784 		unsigned hsize = 1 << ip->i_depth;
785 		unsigned index;
786 		u64 ln;
787 		if (hsize * sizeof(u64) != i_size_read(inode)) {
788 			gfs2_consist_inode(ip);
789 			return ERR_PTR(-EIO);
790 		}
791 
792 		index = name->hash >> (32 - ip->i_depth);
793 		error = get_first_leaf(ip, index, &bh);
794 		if (error)
795 			return ERR_PTR(error);
796 		do {
797 			dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
798 						scan, name, NULL);
799 			if (dent)
800 				goto got_dent;
801 			leaf = (struct gfs2_leaf *)bh->b_data;
802 			ln = be64_to_cpu(leaf->lf_next);
803 			brelse(bh);
804 			if (!ln)
805 				break;
806 
807 			error = get_leaf(ip, ln, &bh);
808 		} while(!error);
809 
810 		return error ? ERR_PTR(error) : NULL;
811 	}
812 
813 
814 	error = gfs2_meta_inode_buffer(ip, &bh);
815 	if (error)
816 		return ERR_PTR(error);
817 	dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL);
818 got_dent:
819 	if (unlikely(dent == NULL || IS_ERR(dent))) {
820 		brelse(bh);
821 		bh = NULL;
822 	}
823 	*pbh = bh;
824 	return dent;
825 }
826 
827 static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh, u16 depth)
828 {
829 	struct gfs2_inode *ip = GFS2_I(inode);
830 	unsigned int n = 1;
831 	u64 bn;
832 	int error;
833 	struct buffer_head *bh;
834 	struct gfs2_leaf *leaf;
835 	struct gfs2_dirent *dent;
836 	struct qstr name = { .name = "" };
837 
838 	error = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL);
839 	if (error)
840 		return NULL;
841 	bh = gfs2_meta_new(ip->i_gl, bn);
842 	if (!bh)
843 		return NULL;
844 
845 	gfs2_trans_add_unrevoke(GFS2_SB(inode), bn, 1);
846 	gfs2_trans_add_meta(ip->i_gl, bh);
847 	gfs2_metatype_set(bh, GFS2_METATYPE_LF, GFS2_FORMAT_LF);
848 	leaf = (struct gfs2_leaf *)bh->b_data;
849 	leaf->lf_depth = cpu_to_be16(depth);
850 	leaf->lf_entries = 0;
851 	leaf->lf_dirent_format = cpu_to_be32(GFS2_FORMAT_DE);
852 	leaf->lf_next = 0;
853 	memset(leaf->lf_reserved, 0, sizeof(leaf->lf_reserved));
854 	dent = (struct gfs2_dirent *)(leaf+1);
855 	gfs2_qstr2dirent(&name, bh->b_size - sizeof(struct gfs2_leaf), dent);
856 	*pbh = bh;
857 	return leaf;
858 }
859 
860 /**
861  * dir_make_exhash - Convert a stuffed directory into an ExHash directory
862  * @dip: The GFS2 inode
863  *
864  * Returns: 0 on success, error code otherwise
865  */
866 
867 static int dir_make_exhash(struct inode *inode)
868 {
869 	struct gfs2_inode *dip = GFS2_I(inode);
870 	struct gfs2_sbd *sdp = GFS2_SB(inode);
871 	struct gfs2_dirent *dent;
872 	struct qstr args;
873 	struct buffer_head *bh, *dibh;
874 	struct gfs2_leaf *leaf;
875 	int y;
876 	u32 x;
877 	__be64 *lp;
878 	u64 bn;
879 	int error;
880 
881 	error = gfs2_meta_inode_buffer(dip, &dibh);
882 	if (error)
883 		return error;
884 
885 	/*  Turn over a new leaf  */
886 
887 	leaf = new_leaf(inode, &bh, 0);
888 	if (!leaf)
889 		return -ENOSPC;
890 	bn = bh->b_blocknr;
891 
892 	gfs2_assert(sdp, dip->i_entries < (1 << 16));
893 	leaf->lf_entries = cpu_to_be16(dip->i_entries);
894 
895 	/*  Copy dirents  */
896 
897 	gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_leaf), dibh,
898 			     sizeof(struct gfs2_dinode));
899 
900 	/*  Find last entry  */
901 
902 	x = 0;
903 	args.len = bh->b_size - sizeof(struct gfs2_dinode) +
904 		   sizeof(struct gfs2_leaf);
905 	args.name = bh->b_data;
906 	dent = gfs2_dirent_scan(&dip->i_inode, bh->b_data, bh->b_size,
907 				gfs2_dirent_last, &args, NULL);
908 	if (!dent) {
909 		brelse(bh);
910 		brelse(dibh);
911 		return -EIO;
912 	}
913 	if (IS_ERR(dent)) {
914 		brelse(bh);
915 		brelse(dibh);
916 		return PTR_ERR(dent);
917 	}
918 
919 	/*  Adjust the last dirent's record length
920 	   (Remember that dent still points to the last entry.)  */
921 
922 	dent->de_rec_len = cpu_to_be16(be16_to_cpu(dent->de_rec_len) +
923 		sizeof(struct gfs2_dinode) -
924 		sizeof(struct gfs2_leaf));
925 
926 	brelse(bh);
927 
928 	/*  We're done with the new leaf block, now setup the new
929 	    hash table.  */
930 
931 	gfs2_trans_add_meta(dip->i_gl, dibh);
932 	gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
933 
934 	lp = (__be64 *)(dibh->b_data + sizeof(struct gfs2_dinode));
935 
936 	for (x = sdp->sd_hash_ptrs; x--; lp++)
937 		*lp = cpu_to_be64(bn);
938 
939 	i_size_write(inode, sdp->sd_sb.sb_bsize / 2);
940 	gfs2_add_inode_blocks(&dip->i_inode, 1);
941 	dip->i_diskflags |= GFS2_DIF_EXHASH;
942 
943 	for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ;
944 	dip->i_depth = y;
945 
946 	gfs2_dinode_out(dip, dibh->b_data);
947 
948 	brelse(dibh);
949 
950 	return 0;
951 }
952 
953 /**
954  * dir_split_leaf - Split a leaf block into two
955  * @dip: The GFS2 inode
956  * @index:
957  * @leaf_no:
958  *
959  * Returns: 0 on success, error code on failure
960  */
961 
962 static int dir_split_leaf(struct inode *inode, const struct qstr *name)
963 {
964 	struct gfs2_inode *dip = GFS2_I(inode);
965 	struct buffer_head *nbh, *obh, *dibh;
966 	struct gfs2_leaf *nleaf, *oleaf;
967 	struct gfs2_dirent *dent = NULL, *prev = NULL, *next = NULL, *new;
968 	u32 start, len, half_len, divider;
969 	u64 bn, leaf_no;
970 	__be64 *lp;
971 	u32 index;
972 	int x, moved = 0;
973 	int error;
974 
975 	index = name->hash >> (32 - dip->i_depth);
976 	error = get_leaf_nr(dip, index, &leaf_no);
977 	if (error)
978 		return error;
979 
980 	/*  Get the old leaf block  */
981 	error = get_leaf(dip, leaf_no, &obh);
982 	if (error)
983 		return error;
984 
985 	oleaf = (struct gfs2_leaf *)obh->b_data;
986 	if (dip->i_depth == be16_to_cpu(oleaf->lf_depth)) {
987 		brelse(obh);
988 		return 1; /* can't split */
989 	}
990 
991 	gfs2_trans_add_meta(dip->i_gl, obh);
992 
993 	nleaf = new_leaf(inode, &nbh, be16_to_cpu(oleaf->lf_depth) + 1);
994 	if (!nleaf) {
995 		brelse(obh);
996 		return -ENOSPC;
997 	}
998 	bn = nbh->b_blocknr;
999 
1000 	/*  Compute the start and len of leaf pointers in the hash table.  */
1001 	len = 1 << (dip->i_depth - be16_to_cpu(oleaf->lf_depth));
1002 	half_len = len >> 1;
1003 	if (!half_len) {
1004 		printk(KERN_WARNING "i_depth %u lf_depth %u index %u\n", dip->i_depth, be16_to_cpu(oleaf->lf_depth), index);
1005 		gfs2_consist_inode(dip);
1006 		error = -EIO;
1007 		goto fail_brelse;
1008 	}
1009 
1010 	start = (index & ~(len - 1));
1011 
1012 	/* Change the pointers.
1013 	   Don't bother distinguishing stuffed from non-stuffed.
1014 	   This code is complicated enough already. */
1015 	lp = kmalloc(half_len * sizeof(__be64), GFP_NOFS);
1016 	if (!lp) {
1017 		error = -ENOMEM;
1018 		goto fail_brelse;
1019 	}
1020 
1021 	/*  Change the pointers  */
1022 	for (x = 0; x < half_len; x++)
1023 		lp[x] = cpu_to_be64(bn);
1024 
1025 	gfs2_dir_hash_inval(dip);
1026 
1027 	error = gfs2_dir_write_data(dip, (char *)lp, start * sizeof(u64),
1028 				    half_len * sizeof(u64));
1029 	if (error != half_len * sizeof(u64)) {
1030 		if (error >= 0)
1031 			error = -EIO;
1032 		goto fail_lpfree;
1033 	}
1034 
1035 	kfree(lp);
1036 
1037 	/*  Compute the divider  */
1038 	divider = (start + half_len) << (32 - dip->i_depth);
1039 
1040 	/*  Copy the entries  */
1041 	dent = (struct gfs2_dirent *)(obh->b_data + sizeof(struct gfs2_leaf));
1042 
1043 	do {
1044 		next = dent;
1045 		if (dirent_next(dip, obh, &next))
1046 			next = NULL;
1047 
1048 		if (!gfs2_dirent_sentinel(dent) &&
1049 		    be32_to_cpu(dent->de_hash) < divider) {
1050 			struct qstr str;
1051 			str.name = (char*)(dent+1);
1052 			str.len = be16_to_cpu(dent->de_name_len);
1053 			str.hash = be32_to_cpu(dent->de_hash);
1054 			new = gfs2_dirent_alloc(inode, nbh, &str);
1055 			if (IS_ERR(new)) {
1056 				error = PTR_ERR(new);
1057 				break;
1058 			}
1059 
1060 			new->de_inum = dent->de_inum; /* No endian worries */
1061 			new->de_type = dent->de_type; /* No endian worries */
1062 			be16_add_cpu(&nleaf->lf_entries, 1);
1063 
1064 			dirent_del(dip, obh, prev, dent);
1065 
1066 			if (!oleaf->lf_entries)
1067 				gfs2_consist_inode(dip);
1068 			be16_add_cpu(&oleaf->lf_entries, -1);
1069 
1070 			if (!prev)
1071 				prev = dent;
1072 
1073 			moved = 1;
1074 		} else {
1075 			prev = dent;
1076 		}
1077 		dent = next;
1078 	} while (dent);
1079 
1080 	oleaf->lf_depth = nleaf->lf_depth;
1081 
1082 	error = gfs2_meta_inode_buffer(dip, &dibh);
1083 	if (!gfs2_assert_withdraw(GFS2_SB(&dip->i_inode), !error)) {
1084 		gfs2_trans_add_meta(dip->i_gl, dibh);
1085 		gfs2_add_inode_blocks(&dip->i_inode, 1);
1086 		gfs2_dinode_out(dip, dibh->b_data);
1087 		brelse(dibh);
1088 	}
1089 
1090 	brelse(obh);
1091 	brelse(nbh);
1092 
1093 	return error;
1094 
1095 fail_lpfree:
1096 	kfree(lp);
1097 
1098 fail_brelse:
1099 	brelse(obh);
1100 	brelse(nbh);
1101 	return error;
1102 }
1103 
1104 /**
1105  * dir_double_exhash - Double size of ExHash table
1106  * @dip: The GFS2 dinode
1107  *
1108  * Returns: 0 on success, error code on failure
1109  */
1110 
1111 static int dir_double_exhash(struct gfs2_inode *dip)
1112 {
1113 	struct buffer_head *dibh;
1114 	u32 hsize;
1115 	u32 hsize_bytes;
1116 	__be64 *hc;
1117 	__be64 *hc2, *h;
1118 	int x;
1119 	int error = 0;
1120 
1121 	hsize = 1 << dip->i_depth;
1122 	hsize_bytes = hsize * sizeof(__be64);
1123 
1124 	hc = gfs2_dir_get_hash_table(dip);
1125 	if (IS_ERR(hc))
1126 		return PTR_ERR(hc);
1127 
1128 	h = hc2 = kmalloc(hsize_bytes * 2, GFP_NOFS | __GFP_NOWARN);
1129 	if (hc2 == NULL)
1130 		hc2 = __vmalloc(hsize_bytes * 2, GFP_NOFS, PAGE_KERNEL);
1131 
1132 	if (!hc2)
1133 		return -ENOMEM;
1134 
1135 	error = gfs2_meta_inode_buffer(dip, &dibh);
1136 	if (error)
1137 		goto out_kfree;
1138 
1139 	for (x = 0; x < hsize; x++) {
1140 		*h++ = *hc;
1141 		*h++ = *hc;
1142 		hc++;
1143 	}
1144 
1145 	error = gfs2_dir_write_data(dip, (char *)hc2, 0, hsize_bytes * 2);
1146 	if (error != (hsize_bytes * 2))
1147 		goto fail;
1148 
1149 	gfs2_dir_hash_inval(dip);
1150 	dip->i_hash_cache = hc2;
1151 	dip->i_depth++;
1152 	gfs2_dinode_out(dip, dibh->b_data);
1153 	brelse(dibh);
1154 	return 0;
1155 
1156 fail:
1157 	/* Replace original hash table & size */
1158 	gfs2_dir_write_data(dip, (char *)hc, 0, hsize_bytes);
1159 	i_size_write(&dip->i_inode, hsize_bytes);
1160 	gfs2_dinode_out(dip, dibh->b_data);
1161 	brelse(dibh);
1162 out_kfree:
1163 	if (is_vmalloc_addr(hc2))
1164 		vfree(hc2);
1165 	else
1166 		kfree(hc2);
1167 	return error;
1168 }
1169 
1170 /**
1171  * compare_dents - compare directory entries by hash value
1172  * @a: first dent
1173  * @b: second dent
1174  *
1175  * When comparing the hash entries of @a to @b:
1176  *   gt: returns 1
1177  *   lt: returns -1
1178  *   eq: returns 0
1179  */
1180 
1181 static int compare_dents(const void *a, const void *b)
1182 {
1183 	const struct gfs2_dirent *dent_a, *dent_b;
1184 	u32 hash_a, hash_b;
1185 	int ret = 0;
1186 
1187 	dent_a = *(const struct gfs2_dirent **)a;
1188 	hash_a = be32_to_cpu(dent_a->de_hash);
1189 
1190 	dent_b = *(const struct gfs2_dirent **)b;
1191 	hash_b = be32_to_cpu(dent_b->de_hash);
1192 
1193 	if (hash_a > hash_b)
1194 		ret = 1;
1195 	else if (hash_a < hash_b)
1196 		ret = -1;
1197 	else {
1198 		unsigned int len_a = be16_to_cpu(dent_a->de_name_len);
1199 		unsigned int len_b = be16_to_cpu(dent_b->de_name_len);
1200 
1201 		if (len_a > len_b)
1202 			ret = 1;
1203 		else if (len_a < len_b)
1204 			ret = -1;
1205 		else
1206 			ret = memcmp(dent_a + 1, dent_b + 1, len_a);
1207 	}
1208 
1209 	return ret;
1210 }
1211 
1212 /**
1213  * do_filldir_main - read out directory entries
1214  * @dip: The GFS2 inode
1215  * @offset: The offset in the file to read from
1216  * @opaque: opaque data to pass to filldir
1217  * @filldir: The function to pass entries to
1218  * @darr: an array of struct gfs2_dirent pointers to read
1219  * @entries: the number of entries in darr
1220  * @copied: pointer to int that's non-zero if a entry has been copied out
1221  *
1222  * Jump through some hoops to make sure that if there are hash collsions,
1223  * they are read out at the beginning of a buffer.  We want to minimize
1224  * the possibility that they will fall into different readdir buffers or
1225  * that someone will want to seek to that location.
1226  *
1227  * Returns: errno, >0 on exception from filldir
1228  */
1229 
1230 static int do_filldir_main(struct gfs2_inode *dip, u64 *offset,
1231 			   void *opaque, filldir_t filldir,
1232 			   const struct gfs2_dirent **darr, u32 entries,
1233 			   int *copied)
1234 {
1235 	const struct gfs2_dirent *dent, *dent_next;
1236 	u64 off, off_next;
1237 	unsigned int x, y;
1238 	int run = 0;
1239 	int error = 0;
1240 
1241 	sort(darr, entries, sizeof(struct gfs2_dirent *), compare_dents, NULL);
1242 
1243 	dent_next = darr[0];
1244 	off_next = be32_to_cpu(dent_next->de_hash);
1245 	off_next = gfs2_disk_hash2offset(off_next);
1246 
1247 	for (x = 0, y = 1; x < entries; x++, y++) {
1248 		dent = dent_next;
1249 		off = off_next;
1250 
1251 		if (y < entries) {
1252 			dent_next = darr[y];
1253 			off_next = be32_to_cpu(dent_next->de_hash);
1254 			off_next = gfs2_disk_hash2offset(off_next);
1255 
1256 			if (off < *offset)
1257 				continue;
1258 			*offset = off;
1259 
1260 			if (off_next == off) {
1261 				if (*copied && !run)
1262 					return 1;
1263 				run = 1;
1264 			} else
1265 				run = 0;
1266 		} else {
1267 			if (off < *offset)
1268 				continue;
1269 			*offset = off;
1270 		}
1271 
1272 		error = filldir(opaque, (const char *)(dent + 1),
1273 				be16_to_cpu(dent->de_name_len),
1274 				off, be64_to_cpu(dent->de_inum.no_addr),
1275 				be16_to_cpu(dent->de_type));
1276 		if (error)
1277 			return 1;
1278 
1279 		*copied = 1;
1280 	}
1281 
1282 	/* Increment the *offset by one, so the next time we come into the
1283 	   do_filldir fxn, we get the next entry instead of the last one in the
1284 	   current leaf */
1285 
1286 	(*offset)++;
1287 
1288 	return 0;
1289 }
1290 
1291 static void *gfs2_alloc_sort_buffer(unsigned size)
1292 {
1293 	void *ptr = NULL;
1294 
1295 	if (size < KMALLOC_MAX_SIZE)
1296 		ptr = kmalloc(size, GFP_NOFS | __GFP_NOWARN);
1297 	if (!ptr)
1298 		ptr = __vmalloc(size, GFP_NOFS, PAGE_KERNEL);
1299 	return ptr;
1300 }
1301 
1302 static void gfs2_free_sort_buffer(void *ptr)
1303 {
1304 	if (is_vmalloc_addr(ptr))
1305 		vfree(ptr);
1306 	else
1307 		kfree(ptr);
1308 }
1309 
1310 static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
1311 			      filldir_t filldir, int *copied, unsigned *depth,
1312 			      u64 leaf_no)
1313 {
1314 	struct gfs2_inode *ip = GFS2_I(inode);
1315 	struct gfs2_sbd *sdp = GFS2_SB(inode);
1316 	struct buffer_head *bh;
1317 	struct gfs2_leaf *lf;
1318 	unsigned entries = 0, entries2 = 0;
1319 	unsigned leaves = 0;
1320 	const struct gfs2_dirent **darr, *dent;
1321 	struct dirent_gather g;
1322 	struct buffer_head **larr;
1323 	int leaf = 0;
1324 	int error, i;
1325 	u64 lfn = leaf_no;
1326 
1327 	do {
1328 		error = get_leaf(ip, lfn, &bh);
1329 		if (error)
1330 			goto out;
1331 		lf = (struct gfs2_leaf *)bh->b_data;
1332 		if (leaves == 0)
1333 			*depth = be16_to_cpu(lf->lf_depth);
1334 		entries += be16_to_cpu(lf->lf_entries);
1335 		leaves++;
1336 		lfn = be64_to_cpu(lf->lf_next);
1337 		brelse(bh);
1338 	} while(lfn);
1339 
1340 	if (!entries)
1341 		return 0;
1342 
1343 	error = -ENOMEM;
1344 	/*
1345 	 * The extra 99 entries are not normally used, but are a buffer
1346 	 * zone in case the number of entries in the leaf is corrupt.
1347 	 * 99 is the maximum number of entries that can fit in a single
1348 	 * leaf block.
1349 	 */
1350 	larr = gfs2_alloc_sort_buffer((leaves + entries + 99) * sizeof(void *));
1351 	if (!larr)
1352 		goto out;
1353 	darr = (const struct gfs2_dirent **)(larr + leaves);
1354 	g.pdent = darr;
1355 	g.offset = 0;
1356 	lfn = leaf_no;
1357 
1358 	do {
1359 		error = get_leaf(ip, lfn, &bh);
1360 		if (error)
1361 			goto out_free;
1362 		lf = (struct gfs2_leaf *)bh->b_data;
1363 		lfn = be64_to_cpu(lf->lf_next);
1364 		if (lf->lf_entries) {
1365 			entries2 += be16_to_cpu(lf->lf_entries);
1366 			dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
1367 						gfs2_dirent_gather, NULL, &g);
1368 			error = PTR_ERR(dent);
1369 			if (IS_ERR(dent))
1370 				goto out_free;
1371 			if (entries2 != g.offset) {
1372 				fs_warn(sdp, "Number of entries corrupt in dir "
1373 						"leaf %llu, entries2 (%u) != "
1374 						"g.offset (%u)\n",
1375 					(unsigned long long)bh->b_blocknr,
1376 					entries2, g.offset);
1377 
1378 				error = -EIO;
1379 				goto out_free;
1380 			}
1381 			error = 0;
1382 			larr[leaf++] = bh;
1383 		} else {
1384 			brelse(bh);
1385 		}
1386 	} while(lfn);
1387 
1388 	BUG_ON(entries2 != entries);
1389 	error = do_filldir_main(ip, offset, opaque, filldir, darr,
1390 				entries, copied);
1391 out_free:
1392 	for(i = 0; i < leaf; i++)
1393 		brelse(larr[i]);
1394 	gfs2_free_sort_buffer(larr);
1395 out:
1396 	return error;
1397 }
1398 
1399 /**
1400  * gfs2_dir_readahead - Issue read-ahead requests for leaf blocks.
1401  *
1402  * Note: we can't calculate each index like dir_e_read can because we don't
1403  * have the leaf, and therefore we don't have the depth, and therefore we
1404  * don't have the length. So we have to just read enough ahead to make up
1405  * for the loss of information.
1406  */
1407 static void gfs2_dir_readahead(struct inode *inode, unsigned hsize, u32 index,
1408 			       struct file_ra_state *f_ra)
1409 {
1410 	struct gfs2_inode *ip = GFS2_I(inode);
1411 	struct gfs2_glock *gl = ip->i_gl;
1412 	struct buffer_head *bh;
1413 	u64 blocknr = 0, last;
1414 	unsigned count;
1415 
1416 	/* First check if we've already read-ahead for the whole range. */
1417 	if (index + MAX_RA_BLOCKS < f_ra->start)
1418 		return;
1419 
1420 	f_ra->start = max((pgoff_t)index, f_ra->start);
1421 	for (count = 0; count < MAX_RA_BLOCKS; count++) {
1422 		if (f_ra->start >= hsize) /* if exceeded the hash table */
1423 			break;
1424 
1425 		last = blocknr;
1426 		blocknr = be64_to_cpu(ip->i_hash_cache[f_ra->start]);
1427 		f_ra->start++;
1428 		if (blocknr == last)
1429 			continue;
1430 
1431 		bh = gfs2_getbuf(gl, blocknr, 1);
1432 		if (trylock_buffer(bh)) {
1433 			if (buffer_uptodate(bh)) {
1434 				unlock_buffer(bh);
1435 				brelse(bh);
1436 				continue;
1437 			}
1438 			bh->b_end_io = end_buffer_read_sync;
1439 			submit_bh(READA | REQ_META, bh);
1440 			continue;
1441 		}
1442 		brelse(bh);
1443 	}
1444 }
1445 
1446 /**
1447  * dir_e_read - Reads the entries from a directory into a filldir buffer
1448  * @dip: dinode pointer
1449  * @offset: the hash of the last entry read shifted to the right once
1450  * @opaque: buffer for the filldir function to fill
1451  * @filldir: points to the filldir function to use
1452  *
1453  * Returns: errno
1454  */
1455 
1456 static int dir_e_read(struct inode *inode, u64 *offset, void *opaque,
1457 		      filldir_t filldir, struct file_ra_state *f_ra)
1458 {
1459 	struct gfs2_inode *dip = GFS2_I(inode);
1460 	u32 hsize, len = 0;
1461 	u32 hash, index;
1462 	__be64 *lp;
1463 	int copied = 0;
1464 	int error = 0;
1465 	unsigned depth = 0;
1466 
1467 	hsize = 1 << dip->i_depth;
1468 	hash = gfs2_dir_offset2hash(*offset);
1469 	index = hash >> (32 - dip->i_depth);
1470 
1471 	if (dip->i_hash_cache == NULL)
1472 		f_ra->start = 0;
1473 	lp = gfs2_dir_get_hash_table(dip);
1474 	if (IS_ERR(lp))
1475 		return PTR_ERR(lp);
1476 
1477 	gfs2_dir_readahead(inode, hsize, index, f_ra);
1478 
1479 	while (index < hsize) {
1480 		error = gfs2_dir_read_leaf(inode, offset, opaque, filldir,
1481 					   &copied, &depth,
1482 					   be64_to_cpu(lp[index]));
1483 		if (error)
1484 			break;
1485 
1486 		len = 1 << (dip->i_depth - depth);
1487 		index = (index & ~(len - 1)) + len;
1488 	}
1489 
1490 	if (error > 0)
1491 		error = 0;
1492 	return error;
1493 }
1494 
1495 int gfs2_dir_read(struct inode *inode, u64 *offset, void *opaque,
1496 		  filldir_t filldir, struct file_ra_state *f_ra)
1497 {
1498 	struct gfs2_inode *dip = GFS2_I(inode);
1499 	struct gfs2_sbd *sdp = GFS2_SB(inode);
1500 	struct dirent_gather g;
1501 	const struct gfs2_dirent **darr, *dent;
1502 	struct buffer_head *dibh;
1503 	int copied = 0;
1504 	int error;
1505 
1506 	if (!dip->i_entries)
1507 		return 0;
1508 
1509 	if (dip->i_diskflags & GFS2_DIF_EXHASH)
1510 		return dir_e_read(inode, offset, opaque, filldir, f_ra);
1511 
1512 	if (!gfs2_is_stuffed(dip)) {
1513 		gfs2_consist_inode(dip);
1514 		return -EIO;
1515 	}
1516 
1517 	error = gfs2_meta_inode_buffer(dip, &dibh);
1518 	if (error)
1519 		return error;
1520 
1521 	error = -ENOMEM;
1522 	/* 96 is max number of dirents which can be stuffed into an inode */
1523 	darr = kmalloc(96 * sizeof(struct gfs2_dirent *), GFP_NOFS);
1524 	if (darr) {
1525 		g.pdent = darr;
1526 		g.offset = 0;
1527 		dent = gfs2_dirent_scan(inode, dibh->b_data, dibh->b_size,
1528 					gfs2_dirent_gather, NULL, &g);
1529 		if (IS_ERR(dent)) {
1530 			error = PTR_ERR(dent);
1531 			goto out;
1532 		}
1533 		if (dip->i_entries != g.offset) {
1534 			fs_warn(sdp, "Number of entries corrupt in dir %llu, "
1535 				"ip->i_entries (%u) != g.offset (%u)\n",
1536 				(unsigned long long)dip->i_no_addr,
1537 				dip->i_entries,
1538 				g.offset);
1539 			error = -EIO;
1540 			goto out;
1541 		}
1542 		error = do_filldir_main(dip, offset, opaque, filldir, darr,
1543 					dip->i_entries, &copied);
1544 out:
1545 		kfree(darr);
1546 	}
1547 
1548 	if (error > 0)
1549 		error = 0;
1550 
1551 	brelse(dibh);
1552 
1553 	return error;
1554 }
1555 
1556 /**
1557  * gfs2_dir_search - Search a directory
1558  * @dip: The GFS2 inode
1559  * @filename:
1560  * @inode:
1561  *
1562  * This routine searches a directory for a file or another directory.
1563  * Assumes a glock is held on dip.
1564  *
1565  * Returns: errno
1566  */
1567 
1568 struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name)
1569 {
1570 	struct buffer_head *bh;
1571 	struct gfs2_dirent *dent;
1572 	struct inode *inode;
1573 
1574 	dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1575 	if (dent) {
1576 		if (IS_ERR(dent))
1577 			return ERR_CAST(dent);
1578 		inode = gfs2_inode_lookup(dir->i_sb,
1579 				be16_to_cpu(dent->de_type),
1580 				be64_to_cpu(dent->de_inum.no_addr),
1581 				be64_to_cpu(dent->de_inum.no_formal_ino), 0);
1582 		brelse(bh);
1583 		return inode;
1584 	}
1585 	return ERR_PTR(-ENOENT);
1586 }
1587 
1588 int gfs2_dir_check(struct inode *dir, const struct qstr *name,
1589 		   const struct gfs2_inode *ip)
1590 {
1591 	struct buffer_head *bh;
1592 	struct gfs2_dirent *dent;
1593 	int ret = -ENOENT;
1594 
1595 	dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
1596 	if (dent) {
1597 		if (IS_ERR(dent))
1598 			return PTR_ERR(dent);
1599 		if (ip) {
1600 			if (be64_to_cpu(dent->de_inum.no_addr) != ip->i_no_addr)
1601 				goto out;
1602 			if (be64_to_cpu(dent->de_inum.no_formal_ino) !=
1603 			    ip->i_no_formal_ino)
1604 				goto out;
1605 			if (unlikely(IF2DT(ip->i_inode.i_mode) !=
1606 			    be16_to_cpu(dent->de_type))) {
1607 				gfs2_consist_inode(GFS2_I(dir));
1608 				ret = -EIO;
1609 				goto out;
1610 			}
1611 		}
1612 		ret = 0;
1613 out:
1614 		brelse(bh);
1615 	}
1616 	return ret;
1617 }
1618 
1619 static int dir_new_leaf(struct inode *inode, const struct qstr *name)
1620 {
1621 	struct buffer_head *bh, *obh;
1622 	struct gfs2_inode *ip = GFS2_I(inode);
1623 	struct gfs2_leaf *leaf, *oleaf;
1624 	int error;
1625 	u32 index;
1626 	u64 bn;
1627 
1628 	index = name->hash >> (32 - ip->i_depth);
1629 	error = get_first_leaf(ip, index, &obh);
1630 	if (error)
1631 		return error;
1632 	do {
1633 		oleaf = (struct gfs2_leaf *)obh->b_data;
1634 		bn = be64_to_cpu(oleaf->lf_next);
1635 		if (!bn)
1636 			break;
1637 		brelse(obh);
1638 		error = get_leaf(ip, bn, &obh);
1639 		if (error)
1640 			return error;
1641 	} while(1);
1642 
1643 	gfs2_trans_add_meta(ip->i_gl, obh);
1644 
1645 	leaf = new_leaf(inode, &bh, be16_to_cpu(oleaf->lf_depth));
1646 	if (!leaf) {
1647 		brelse(obh);
1648 		return -ENOSPC;
1649 	}
1650 	oleaf->lf_next = cpu_to_be64(bh->b_blocknr);
1651 	brelse(bh);
1652 	brelse(obh);
1653 
1654 	error = gfs2_meta_inode_buffer(ip, &bh);
1655 	if (error)
1656 		return error;
1657 	gfs2_trans_add_meta(ip->i_gl, bh);
1658 	gfs2_add_inode_blocks(&ip->i_inode, 1);
1659 	gfs2_dinode_out(ip, bh->b_data);
1660 	brelse(bh);
1661 	return 0;
1662 }
1663 
1664 /**
1665  * gfs2_dir_add - Add new filename into directory
1666  * @dip: The GFS2 inode
1667  * @filename: The new name
1668  * @inode: The inode number of the entry
1669  * @type: The type of the entry
1670  *
1671  * Returns: 0 on success, error code on failure
1672  */
1673 
1674 int gfs2_dir_add(struct inode *inode, const struct qstr *name,
1675 		 const struct gfs2_inode *nip)
1676 {
1677 	struct gfs2_inode *ip = GFS2_I(inode);
1678 	struct buffer_head *bh;
1679 	struct gfs2_dirent *dent;
1680 	struct gfs2_leaf *leaf;
1681 	int error;
1682 
1683 	while(1) {
1684 		dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space,
1685 					  &bh);
1686 		if (dent) {
1687 			if (IS_ERR(dent))
1688 				return PTR_ERR(dent);
1689 			dent = gfs2_init_dirent(inode, dent, name, bh);
1690 			gfs2_inum_out(nip, dent);
1691 			dent->de_type = cpu_to_be16(IF2DT(nip->i_inode.i_mode));
1692 			if (ip->i_diskflags & GFS2_DIF_EXHASH) {
1693 				leaf = (struct gfs2_leaf *)bh->b_data;
1694 				be16_add_cpu(&leaf->lf_entries, 1);
1695 			}
1696 			brelse(bh);
1697 			ip->i_entries++;
1698 			ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
1699 			if (S_ISDIR(nip->i_inode.i_mode))
1700 				inc_nlink(&ip->i_inode);
1701 			mark_inode_dirty(inode);
1702 			error = 0;
1703 			break;
1704 		}
1705 		if (!(ip->i_diskflags & GFS2_DIF_EXHASH)) {
1706 			error = dir_make_exhash(inode);
1707 			if (error)
1708 				break;
1709 			continue;
1710 		}
1711 		error = dir_split_leaf(inode, name);
1712 		if (error == 0)
1713 			continue;
1714 		if (error < 0)
1715 			break;
1716 		if (ip->i_depth < GFS2_DIR_MAX_DEPTH) {
1717 			error = dir_double_exhash(ip);
1718 			if (error)
1719 				break;
1720 			error = dir_split_leaf(inode, name);
1721 			if (error < 0)
1722 				break;
1723 			if (error == 0)
1724 				continue;
1725 		}
1726 		error = dir_new_leaf(inode, name);
1727 		if (!error)
1728 			continue;
1729 		error = -ENOSPC;
1730 		break;
1731 	}
1732 	return error;
1733 }
1734 
1735 
1736 /**
1737  * gfs2_dir_del - Delete a directory entry
1738  * @dip: The GFS2 inode
1739  * @filename: The filename
1740  *
1741  * Returns: 0 on success, error code on failure
1742  */
1743 
1744 int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry)
1745 {
1746 	const struct qstr *name = &dentry->d_name;
1747 	struct gfs2_dirent *dent, *prev = NULL;
1748 	struct buffer_head *bh;
1749 
1750 	/* Returns _either_ the entry (if its first in block) or the
1751 	   previous entry otherwise */
1752 	dent = gfs2_dirent_search(&dip->i_inode, name, gfs2_dirent_prev, &bh);
1753 	if (!dent) {
1754 		gfs2_consist_inode(dip);
1755 		return -EIO;
1756 	}
1757 	if (IS_ERR(dent)) {
1758 		gfs2_consist_inode(dip);
1759 		return PTR_ERR(dent);
1760 	}
1761 	/* If not first in block, adjust pointers accordingly */
1762 	if (gfs2_dirent_find(dent, name, NULL) == 0) {
1763 		prev = dent;
1764 		dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len));
1765 	}
1766 
1767 	dirent_del(dip, bh, prev, dent);
1768 	if (dip->i_diskflags & GFS2_DIF_EXHASH) {
1769 		struct gfs2_leaf *leaf = (struct gfs2_leaf *)bh->b_data;
1770 		u16 entries = be16_to_cpu(leaf->lf_entries);
1771 		if (!entries)
1772 			gfs2_consist_inode(dip);
1773 		leaf->lf_entries = cpu_to_be16(--entries);
1774 	}
1775 	brelse(bh);
1776 
1777 	if (!dip->i_entries)
1778 		gfs2_consist_inode(dip);
1779 	dip->i_entries--;
1780 	dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
1781 	if (S_ISDIR(dentry->d_inode->i_mode))
1782 		drop_nlink(&dip->i_inode);
1783 	mark_inode_dirty(&dip->i_inode);
1784 
1785 	return 0;
1786 }
1787 
1788 /**
1789  * gfs2_dir_mvino - Change inode number of directory entry
1790  * @dip: The GFS2 inode
1791  * @filename:
1792  * @new_inode:
1793  *
1794  * This routine changes the inode number of a directory entry.  It's used
1795  * by rename to change ".." when a directory is moved.
1796  * Assumes a glock is held on dvp.
1797  *
1798  * Returns: errno
1799  */
1800 
1801 int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
1802 		   const struct gfs2_inode *nip, unsigned int new_type)
1803 {
1804 	struct buffer_head *bh;
1805 	struct gfs2_dirent *dent;
1806 	int error;
1807 
1808 	dent = gfs2_dirent_search(&dip->i_inode, filename, gfs2_dirent_find, &bh);
1809 	if (!dent) {
1810 		gfs2_consist_inode(dip);
1811 		return -EIO;
1812 	}
1813 	if (IS_ERR(dent))
1814 		return PTR_ERR(dent);
1815 
1816 	gfs2_trans_add_meta(dip->i_gl, bh);
1817 	gfs2_inum_out(nip, dent);
1818 	dent->de_type = cpu_to_be16(new_type);
1819 
1820 	if (dip->i_diskflags & GFS2_DIF_EXHASH) {
1821 		brelse(bh);
1822 		error = gfs2_meta_inode_buffer(dip, &bh);
1823 		if (error)
1824 			return error;
1825 		gfs2_trans_add_meta(dip->i_gl, bh);
1826 	}
1827 
1828 	dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
1829 	gfs2_dinode_out(dip, bh->b_data);
1830 	brelse(bh);
1831 	return 0;
1832 }
1833 
1834 /**
1835  * leaf_dealloc - Deallocate a directory leaf
1836  * @dip: the directory
1837  * @index: the hash table offset in the directory
1838  * @len: the number of pointers to this leaf
1839  * @leaf_no: the leaf number
1840  * @leaf_bh: buffer_head for the starting leaf
1841  * last_dealloc: 1 if this is the final dealloc for the leaf, else 0
1842  *
1843  * Returns: errno
1844  */
1845 
1846 static int leaf_dealloc(struct gfs2_inode *dip, u32 index, u32 len,
1847 			u64 leaf_no, struct buffer_head *leaf_bh,
1848 			int last_dealloc)
1849 {
1850 	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
1851 	struct gfs2_leaf *tmp_leaf;
1852 	struct gfs2_rgrp_list rlist;
1853 	struct buffer_head *bh, *dibh;
1854 	u64 blk, nblk;
1855 	unsigned int rg_blocks = 0, l_blocks = 0;
1856 	char *ht;
1857 	unsigned int x, size = len * sizeof(u64);
1858 	int error;
1859 
1860 	error = gfs2_rindex_update(sdp);
1861 	if (error)
1862 		return error;
1863 
1864 	memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
1865 
1866 	ht = kzalloc(size, GFP_NOFS);
1867 	if (ht == NULL)
1868 		ht = vzalloc(size);
1869 	if (!ht)
1870 		return -ENOMEM;
1871 
1872 	error = gfs2_quota_hold(dip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1873 	if (error)
1874 		goto out;
1875 
1876 	/*  Count the number of leaves  */
1877 	bh = leaf_bh;
1878 
1879 	for (blk = leaf_no; blk; blk = nblk) {
1880 		if (blk != leaf_no) {
1881 			error = get_leaf(dip, blk, &bh);
1882 			if (error)
1883 				goto out_rlist;
1884 		}
1885 		tmp_leaf = (struct gfs2_leaf *)bh->b_data;
1886 		nblk = be64_to_cpu(tmp_leaf->lf_next);
1887 		if (blk != leaf_no)
1888 			brelse(bh);
1889 
1890 		gfs2_rlist_add(dip, &rlist, blk);
1891 		l_blocks++;
1892 	}
1893 
1894 	gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE);
1895 
1896 	for (x = 0; x < rlist.rl_rgrps; x++) {
1897 		struct gfs2_rgrpd *rgd;
1898 		rgd = rlist.rl_ghs[x].gh_gl->gl_object;
1899 		rg_blocks += rgd->rd_length;
1900 	}
1901 
1902 	error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
1903 	if (error)
1904 		goto out_rlist;
1905 
1906 	error = gfs2_trans_begin(sdp,
1907 			rg_blocks + (DIV_ROUND_UP(size, sdp->sd_jbsize) + 1) +
1908 			RES_DINODE + RES_STATFS + RES_QUOTA, l_blocks);
1909 	if (error)
1910 		goto out_rg_gunlock;
1911 
1912 	bh = leaf_bh;
1913 
1914 	for (blk = leaf_no; blk; blk = nblk) {
1915 		if (blk != leaf_no) {
1916 			error = get_leaf(dip, blk, &bh);
1917 			if (error)
1918 				goto out_end_trans;
1919 		}
1920 		tmp_leaf = (struct gfs2_leaf *)bh->b_data;
1921 		nblk = be64_to_cpu(tmp_leaf->lf_next);
1922 		if (blk != leaf_no)
1923 			brelse(bh);
1924 
1925 		gfs2_free_meta(dip, blk, 1);
1926 		gfs2_add_inode_blocks(&dip->i_inode, -1);
1927 	}
1928 
1929 	error = gfs2_dir_write_data(dip, ht, index * sizeof(u64), size);
1930 	if (error != size) {
1931 		if (error >= 0)
1932 			error = -EIO;
1933 		goto out_end_trans;
1934 	}
1935 
1936 	error = gfs2_meta_inode_buffer(dip, &dibh);
1937 	if (error)
1938 		goto out_end_trans;
1939 
1940 	gfs2_trans_add_meta(dip->i_gl, dibh);
1941 	/* On the last dealloc, make this a regular file in case we crash.
1942 	   (We don't want to free these blocks a second time.)  */
1943 	if (last_dealloc)
1944 		dip->i_inode.i_mode = S_IFREG;
1945 	gfs2_dinode_out(dip, dibh->b_data);
1946 	brelse(dibh);
1947 
1948 out_end_trans:
1949 	gfs2_trans_end(sdp);
1950 out_rg_gunlock:
1951 	gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
1952 out_rlist:
1953 	gfs2_rlist_free(&rlist);
1954 	gfs2_quota_unhold(dip);
1955 out:
1956 	if (is_vmalloc_addr(ht))
1957 		vfree(ht);
1958 	else
1959 		kfree(ht);
1960 	return error;
1961 }
1962 
1963 /**
1964  * gfs2_dir_exhash_dealloc - free all the leaf blocks in a directory
1965  * @dip: the directory
1966  *
1967  * Dealloc all on-disk directory leaves to FREEMETA state
1968  * Change on-disk inode type to "regular file"
1969  *
1970  * Returns: errno
1971  */
1972 
1973 int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip)
1974 {
1975 	struct buffer_head *bh;
1976 	struct gfs2_leaf *leaf;
1977 	u32 hsize, len;
1978 	u32 index = 0, next_index;
1979 	__be64 *lp;
1980 	u64 leaf_no;
1981 	int error = 0, last;
1982 
1983 	hsize = 1 << dip->i_depth;
1984 
1985 	lp = gfs2_dir_get_hash_table(dip);
1986 	if (IS_ERR(lp))
1987 		return PTR_ERR(lp);
1988 
1989 	while (index < hsize) {
1990 		leaf_no = be64_to_cpu(lp[index]);
1991 		if (leaf_no) {
1992 			error = get_leaf(dip, leaf_no, &bh);
1993 			if (error)
1994 				goto out;
1995 			leaf = (struct gfs2_leaf *)bh->b_data;
1996 			len = 1 << (dip->i_depth - be16_to_cpu(leaf->lf_depth));
1997 
1998 			next_index = (index & ~(len - 1)) + len;
1999 			last = ((next_index >= hsize) ? 1 : 0);
2000 			error = leaf_dealloc(dip, index, len, leaf_no, bh,
2001 					     last);
2002 			brelse(bh);
2003 			if (error)
2004 				goto out;
2005 			index = next_index;
2006 		} else
2007 			index++;
2008 	}
2009 
2010 	if (index != hsize) {
2011 		gfs2_consist_inode(dip);
2012 		error = -EIO;
2013 	}
2014 
2015 out:
2016 
2017 	return error;
2018 }
2019 
2020 /**
2021  * gfs2_diradd_alloc_required - find if adding entry will require an allocation
2022  * @ip: the file being written to
2023  * @filname: the filename that's going to be added
2024  *
2025  * Returns: 1 if alloc required, 0 if not, -ve on error
2026  */
2027 
2028 int gfs2_diradd_alloc_required(struct inode *inode, const struct qstr *name)
2029 {
2030 	struct gfs2_dirent *dent;
2031 	struct buffer_head *bh;
2032 
2033 	dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space, &bh);
2034 	if (!dent) {
2035 		return 1;
2036 	}
2037 	if (IS_ERR(dent))
2038 		return PTR_ERR(dent);
2039 	brelse(bh);
2040 	return 0;
2041 }
2042 
2043