xref: /openbmc/linux/fs/ocfs2/dir.c (revision 9ac8d3fb)
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * dir.c
5  *
6  * Creates, reads, walks and deletes directory-nodes
7  *
8  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
9  *
10  *  Portions of this code from linux/fs/ext3/dir.c
11  *
12  *  Copyright (C) 1992, 1993, 1994, 1995
13  *  Remy Card (card@masi.ibp.fr)
14  *  Laboratoire MASI - Institut Blaise pascal
15  *  Universite Pierre et Marie Curie (Paris VI)
16  *
17  *   from
18  *
19  *   linux/fs/minix/dir.c
20  *
21  *   Copyright (C) 1991, 1992 Linux Torvalds
22  *
23  * This program is free software; you can redistribute it and/or
24  * modify it under the terms of the GNU General Public
25  * License as published by the Free Software Foundation; either
26  * version 2 of the License, or (at your option) any later version.
27  *
28  * This program is distributed in the hope that it will be useful,
29  * but WITHOUT ANY WARRANTY; without even the implied warranty of
30  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
31  * General Public License for more details.
32  *
33  * You should have received a copy of the GNU General Public
34  * License along with this program; if not, write to the
35  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
36  * Boston, MA 021110-1307, USA.
37  */
38 
39 #include <linux/fs.h>
40 #include <linux/types.h>
41 #include <linux/slab.h>
42 #include <linux/highmem.h>
43 
44 #define MLOG_MASK_PREFIX ML_NAMEI
45 #include <cluster/masklog.h>
46 
47 #include "ocfs2.h"
48 
49 #include "alloc.h"
50 #include "dir.h"
51 #include "dlmglue.h"
52 #include "extent_map.h"
53 #include "file.h"
54 #include "inode.h"
55 #include "journal.h"
56 #include "namei.h"
57 #include "suballoc.h"
58 #include "super.h"
59 #include "uptodate.h"
60 
61 #include "buffer_head_io.h"
62 
63 #define NAMEI_RA_CHUNKS  2
64 #define NAMEI_RA_BLOCKS  4
65 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
66 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
67 
68 static unsigned char ocfs2_filetype_table[] = {
69 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
70 };
71 
72 static int ocfs2_extend_dir(struct ocfs2_super *osb,
73 			    struct inode *dir,
74 			    struct buffer_head *parent_fe_bh,
75 			    unsigned int blocks_wanted,
76 			    struct buffer_head **new_de_bh);
77 static int ocfs2_do_extend_dir(struct super_block *sb,
78 			       handle_t *handle,
79 			       struct inode *dir,
80 			       struct buffer_head *parent_fe_bh,
81 			       struct ocfs2_alloc_context *data_ac,
82 			       struct ocfs2_alloc_context *meta_ac,
83 			       struct buffer_head **new_bh);
84 
85 static struct buffer_head *ocfs2_bread(struct inode *inode,
86 				       int block, int *err, int reada)
87 {
88 	struct buffer_head *bh = NULL;
89 	int tmperr;
90 	u64 p_blkno;
91 	int readflags = 0;
92 
93 	if (reada)
94 		readflags |= OCFS2_BH_READAHEAD;
95 
96 	if (((u64)block << inode->i_sb->s_blocksize_bits) >=
97 	    i_size_read(inode)) {
98 		BUG_ON(!reada);
99 		return NULL;
100 	}
101 
102 	down_read(&OCFS2_I(inode)->ip_alloc_sem);
103 	tmperr = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
104 					     NULL);
105 	up_read(&OCFS2_I(inode)->ip_alloc_sem);
106 	if (tmperr < 0) {
107 		mlog_errno(tmperr);
108 		goto fail;
109 	}
110 
111 	tmperr = ocfs2_read_blocks(inode, p_blkno, 1, &bh, readflags);
112 	if (tmperr < 0)
113 		goto fail;
114 
115 	tmperr = 0;
116 
117 	*err = 0;
118 	return bh;
119 
120 fail:
121 	brelse(bh);
122 	bh = NULL;
123 
124 	*err = -EIO;
125 	return NULL;
126 }
127 
128 /*
129  * bh passed here can be an inode block or a dir data block, depending
130  * on the inode inline data flag.
131  */
132 static int ocfs2_check_dir_entry(struct inode * dir,
133 				 struct ocfs2_dir_entry * de,
134 				 struct buffer_head * bh,
135 				 unsigned long offset)
136 {
137 	const char *error_msg = NULL;
138 	const int rlen = le16_to_cpu(de->rec_len);
139 
140 	if (rlen < OCFS2_DIR_REC_LEN(1))
141 		error_msg = "rec_len is smaller than minimal";
142 	else if (rlen % 4 != 0)
143 		error_msg = "rec_len % 4 != 0";
144 	else if (rlen < OCFS2_DIR_REC_LEN(de->name_len))
145 		error_msg = "rec_len is too small for name_len";
146 	else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)
147 		error_msg = "directory entry across blocks";
148 
149 	if (error_msg != NULL)
150 		mlog(ML_ERROR, "bad entry in directory #%llu: %s - "
151 		     "offset=%lu, inode=%llu, rec_len=%d, name_len=%d\n",
152 		     (unsigned long long)OCFS2_I(dir)->ip_blkno, error_msg,
153 		     offset, (unsigned long long)le64_to_cpu(de->inode), rlen,
154 		     de->name_len);
155 	return error_msg == NULL ? 1 : 0;
156 }
157 
158 static inline int ocfs2_match(int len,
159 			      const char * const name,
160 			      struct ocfs2_dir_entry *de)
161 {
162 	if (len != de->name_len)
163 		return 0;
164 	if (!de->inode)
165 		return 0;
166 	return !memcmp(name, de->name, len);
167 }
168 
169 /*
170  * Returns 0 if not found, -1 on failure, and 1 on success
171  */
172 static int inline ocfs2_search_dirblock(struct buffer_head *bh,
173 					struct inode *dir,
174 					const char *name, int namelen,
175 					unsigned long offset,
176 					char *first_de,
177 					unsigned int bytes,
178 					struct ocfs2_dir_entry **res_dir)
179 {
180 	struct ocfs2_dir_entry *de;
181 	char *dlimit, *de_buf;
182 	int de_len;
183 	int ret = 0;
184 
185 	mlog_entry_void();
186 
187 	de_buf = first_de;
188 	dlimit = de_buf + bytes;
189 
190 	while (de_buf < dlimit) {
191 		/* this code is executed quadratically often */
192 		/* do minimal checking `by hand' */
193 
194 		de = (struct ocfs2_dir_entry *) de_buf;
195 
196 		if (de_buf + namelen <= dlimit &&
197 		    ocfs2_match(namelen, name, de)) {
198 			/* found a match - just to be sure, do a full check */
199 			if (!ocfs2_check_dir_entry(dir, de, bh, offset)) {
200 				ret = -1;
201 				goto bail;
202 			}
203 			*res_dir = de;
204 			ret = 1;
205 			goto bail;
206 		}
207 
208 		/* prevent looping on a bad block */
209 		de_len = le16_to_cpu(de->rec_len);
210 		if (de_len <= 0) {
211 			ret = -1;
212 			goto bail;
213 		}
214 
215 		de_buf += de_len;
216 		offset += de_len;
217 	}
218 
219 bail:
220 	mlog_exit(ret);
221 	return ret;
222 }
223 
224 static struct buffer_head *ocfs2_find_entry_id(const char *name,
225 					       int namelen,
226 					       struct inode *dir,
227 					       struct ocfs2_dir_entry **res_dir)
228 {
229 	int ret, found;
230 	struct buffer_head *di_bh = NULL;
231 	struct ocfs2_dinode *di;
232 	struct ocfs2_inline_data *data;
233 
234 	ret = ocfs2_read_block(dir, OCFS2_I(dir)->ip_blkno, &di_bh);
235 	if (ret) {
236 		mlog_errno(ret);
237 		goto out;
238 	}
239 
240 	di = (struct ocfs2_dinode *)di_bh->b_data;
241 	data = &di->id2.i_data;
242 
243 	found = ocfs2_search_dirblock(di_bh, dir, name, namelen, 0,
244 				      data->id_data, i_size_read(dir), res_dir);
245 	if (found == 1)
246 		return di_bh;
247 
248 	brelse(di_bh);
249 out:
250 	return NULL;
251 }
252 
253 static struct buffer_head *ocfs2_find_entry_el(const char *name, int namelen,
254 					       struct inode *dir,
255 					       struct ocfs2_dir_entry **res_dir)
256 {
257 	struct super_block *sb;
258 	struct buffer_head *bh_use[NAMEI_RA_SIZE];
259 	struct buffer_head *bh, *ret = NULL;
260 	unsigned long start, block, b;
261 	int ra_max = 0;		/* Number of bh's in the readahead
262 				   buffer, bh_use[] */
263 	int ra_ptr = 0;		/* Current index into readahead
264 				   buffer */
265 	int num = 0;
266 	int nblocks, i, err;
267 
268 	mlog_entry_void();
269 
270 	sb = dir->i_sb;
271 
272 	nblocks = i_size_read(dir) >> sb->s_blocksize_bits;
273 	start = OCFS2_I(dir)->ip_dir_start_lookup;
274 	if (start >= nblocks)
275 		start = 0;
276 	block = start;
277 
278 restart:
279 	do {
280 		/*
281 		 * We deal with the read-ahead logic here.
282 		 */
283 		if (ra_ptr >= ra_max) {
284 			/* Refill the readahead buffer */
285 			ra_ptr = 0;
286 			b = block;
287 			for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
288 				/*
289 				 * Terminate if we reach the end of the
290 				 * directory and must wrap, or if our
291 				 * search has finished at this block.
292 				 */
293 				if (b >= nblocks || (num && block == start)) {
294 					bh_use[ra_max] = NULL;
295 					break;
296 				}
297 				num++;
298 
299 				bh = ocfs2_bread(dir, b++, &err, 1);
300 				bh_use[ra_max] = bh;
301 			}
302 		}
303 		if ((bh = bh_use[ra_ptr++]) == NULL)
304 			goto next;
305 		if (ocfs2_read_block(dir, block, &bh)) {
306 			/* read error, skip block & hope for the best.
307 			 * ocfs2_read_block() has released the bh. */
308 			ocfs2_error(dir->i_sb, "reading directory %llu, "
309 				    "offset %lu\n",
310 				    (unsigned long long)OCFS2_I(dir)->ip_blkno,
311 				    block);
312 			goto next;
313 		}
314 		i = ocfs2_search_dirblock(bh, dir, name, namelen,
315 					  block << sb->s_blocksize_bits,
316 					  bh->b_data, sb->s_blocksize,
317 					  res_dir);
318 		if (i == 1) {
319 			OCFS2_I(dir)->ip_dir_start_lookup = block;
320 			ret = bh;
321 			goto cleanup_and_exit;
322 		} else {
323 			brelse(bh);
324 			if (i < 0)
325 				goto cleanup_and_exit;
326 		}
327 	next:
328 		if (++block >= nblocks)
329 			block = 0;
330 	} while (block != start);
331 
332 	/*
333 	 * If the directory has grown while we were searching, then
334 	 * search the last part of the directory before giving up.
335 	 */
336 	block = nblocks;
337 	nblocks = i_size_read(dir) >> sb->s_blocksize_bits;
338 	if (block < nblocks) {
339 		start = 0;
340 		goto restart;
341 	}
342 
343 cleanup_and_exit:
344 	/* Clean up the read-ahead blocks */
345 	for (; ra_ptr < ra_max; ra_ptr++)
346 		brelse(bh_use[ra_ptr]);
347 
348 	mlog_exit_ptr(ret);
349 	return ret;
350 }
351 
352 /*
353  * Try to find an entry of the provided name within 'dir'.
354  *
355  * If nothing was found, NULL is returned. Otherwise, a buffer_head
356  * and pointer to the dir entry are passed back.
357  *
358  * Caller can NOT assume anything about the contents of the
359  * buffer_head - it is passed back only so that it can be passed into
360  * any one of the manipulation functions (add entry, delete entry,
361  * etc). As an example, bh in the extent directory case is a data
362  * block, in the inline-data case it actually points to an inode.
363  */
364 struct buffer_head *ocfs2_find_entry(const char *name, int namelen,
365 				     struct inode *dir,
366 				     struct ocfs2_dir_entry **res_dir)
367 {
368 	*res_dir = NULL;
369 
370 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
371 		return ocfs2_find_entry_id(name, namelen, dir, res_dir);
372 
373 	return ocfs2_find_entry_el(name, namelen, dir, res_dir);
374 }
375 
376 /*
377  * Update inode number and type of a previously found directory entry.
378  */
379 int ocfs2_update_entry(struct inode *dir, handle_t *handle,
380 		       struct buffer_head *de_bh, struct ocfs2_dir_entry *de,
381 		       struct inode *new_entry_inode)
382 {
383 	int ret;
384 
385 	/*
386 	 * The same code works fine for both inline-data and extent
387 	 * based directories, so no need to split this up.
388 	 */
389 
390 	ret = ocfs2_journal_access(handle, dir, de_bh,
391 				   OCFS2_JOURNAL_ACCESS_WRITE);
392 	if (ret) {
393 		mlog_errno(ret);
394 		goto out;
395 	}
396 
397 	de->inode = cpu_to_le64(OCFS2_I(new_entry_inode)->ip_blkno);
398 	ocfs2_set_de_type(de, new_entry_inode->i_mode);
399 
400 	ocfs2_journal_dirty(handle, de_bh);
401 
402 out:
403 	return ret;
404 }
405 
406 static int __ocfs2_delete_entry(handle_t *handle, struct inode *dir,
407 				struct ocfs2_dir_entry *de_del,
408 				struct buffer_head *bh, char *first_de,
409 				unsigned int bytes)
410 {
411 	struct ocfs2_dir_entry *de, *pde;
412 	int i, status = -ENOENT;
413 
414 	mlog_entry("(0x%p, 0x%p, 0x%p, 0x%p)\n", handle, dir, de_del, bh);
415 
416 	i = 0;
417 	pde = NULL;
418 	de = (struct ocfs2_dir_entry *) first_de;
419 	while (i < bytes) {
420 		if (!ocfs2_check_dir_entry(dir, de, bh, i)) {
421 			status = -EIO;
422 			mlog_errno(status);
423 			goto bail;
424 		}
425 		if (de == de_del)  {
426 			status = ocfs2_journal_access(handle, dir, bh,
427 						      OCFS2_JOURNAL_ACCESS_WRITE);
428 			if (status < 0) {
429 				status = -EIO;
430 				mlog_errno(status);
431 				goto bail;
432 			}
433 			if (pde)
434 				le16_add_cpu(&pde->rec_len,
435 						le16_to_cpu(de->rec_len));
436 			else
437 				de->inode = 0;
438 			dir->i_version++;
439 			status = ocfs2_journal_dirty(handle, bh);
440 			goto bail;
441 		}
442 		i += le16_to_cpu(de->rec_len);
443 		pde = de;
444 		de = (struct ocfs2_dir_entry *)((char *)de + le16_to_cpu(de->rec_len));
445 	}
446 bail:
447 	mlog_exit(status);
448 	return status;
449 }
450 
451 static inline int ocfs2_delete_entry_id(handle_t *handle,
452 					struct inode *dir,
453 					struct ocfs2_dir_entry *de_del,
454 					struct buffer_head *bh)
455 {
456 	int ret;
457 	struct buffer_head *di_bh = NULL;
458 	struct ocfs2_dinode *di;
459 	struct ocfs2_inline_data *data;
460 
461 	ret = ocfs2_read_block(dir, OCFS2_I(dir)->ip_blkno, &di_bh);
462 	if (ret) {
463 		mlog_errno(ret);
464 		goto out;
465 	}
466 
467 	di = (struct ocfs2_dinode *)di_bh->b_data;
468 	data = &di->id2.i_data;
469 
470 	ret = __ocfs2_delete_entry(handle, dir, de_del, bh, data->id_data,
471 				   i_size_read(dir));
472 
473 	brelse(di_bh);
474 out:
475 	return ret;
476 }
477 
478 static inline int ocfs2_delete_entry_el(handle_t *handle,
479 					struct inode *dir,
480 					struct ocfs2_dir_entry *de_del,
481 					struct buffer_head *bh)
482 {
483 	return __ocfs2_delete_entry(handle, dir, de_del, bh, bh->b_data,
484 				    bh->b_size);
485 }
486 
487 /*
488  * ocfs2_delete_entry deletes a directory entry by merging it with the
489  * previous entry
490  */
491 int ocfs2_delete_entry(handle_t *handle,
492 		       struct inode *dir,
493 		       struct ocfs2_dir_entry *de_del,
494 		       struct buffer_head *bh)
495 {
496 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
497 		return ocfs2_delete_entry_id(handle, dir, de_del, bh);
498 
499 	return ocfs2_delete_entry_el(handle, dir, de_del, bh);
500 }
501 
502 /*
503  * Check whether 'de' has enough room to hold an entry of
504  * 'new_rec_len' bytes.
505  */
506 static inline int ocfs2_dirent_would_fit(struct ocfs2_dir_entry *de,
507 					 unsigned int new_rec_len)
508 {
509 	unsigned int de_really_used;
510 
511 	/* Check whether this is an empty record with enough space */
512 	if (le64_to_cpu(de->inode) == 0 &&
513 	    le16_to_cpu(de->rec_len) >= new_rec_len)
514 		return 1;
515 
516 	/*
517 	 * Record might have free space at the end which we can
518 	 * use.
519 	 */
520 	de_really_used = OCFS2_DIR_REC_LEN(de->name_len);
521 	if (le16_to_cpu(de->rec_len) >= (de_really_used + new_rec_len))
522 	    return 1;
523 
524 	return 0;
525 }
526 
527 /* we don't always have a dentry for what we want to add, so people
528  * like orphan dir can call this instead.
529  *
530  * If you pass me insert_bh, I'll skip the search of the other dir
531  * blocks and put the record in there.
532  */
533 int __ocfs2_add_entry(handle_t *handle,
534 		      struct inode *dir,
535 		      const char *name, int namelen,
536 		      struct inode *inode, u64 blkno,
537 		      struct buffer_head *parent_fe_bh,
538 		      struct buffer_head *insert_bh)
539 {
540 	unsigned long offset;
541 	unsigned short rec_len;
542 	struct ocfs2_dir_entry *de, *de1;
543 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_fe_bh->b_data;
544 	struct super_block *sb = dir->i_sb;
545 	int retval, status;
546 	unsigned int size = sb->s_blocksize;
547 	char *data_start = insert_bh->b_data;
548 
549 	mlog_entry_void();
550 
551 	if (!namelen)
552 		return -EINVAL;
553 
554 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
555 		data_start = di->id2.i_data.id_data;
556 		size = i_size_read(dir);
557 
558 		BUG_ON(insert_bh != parent_fe_bh);
559 	}
560 
561 	rec_len = OCFS2_DIR_REC_LEN(namelen);
562 	offset = 0;
563 	de = (struct ocfs2_dir_entry *) data_start;
564 	while (1) {
565 		BUG_ON((char *)de >= (size + data_start));
566 
567 		/* These checks should've already been passed by the
568 		 * prepare function, but I guess we can leave them
569 		 * here anyway. */
570 		if (!ocfs2_check_dir_entry(dir, de, insert_bh, offset)) {
571 			retval = -ENOENT;
572 			goto bail;
573 		}
574 		if (ocfs2_match(namelen, name, de)) {
575 			retval = -EEXIST;
576 			goto bail;
577 		}
578 
579 		if (ocfs2_dirent_would_fit(de, rec_len)) {
580 			dir->i_mtime = dir->i_ctime = CURRENT_TIME;
581 			retval = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh);
582 			if (retval < 0) {
583 				mlog_errno(retval);
584 				goto bail;
585 			}
586 
587 			status = ocfs2_journal_access(handle, dir, insert_bh,
588 						      OCFS2_JOURNAL_ACCESS_WRITE);
589 			/* By now the buffer is marked for journaling */
590 			offset += le16_to_cpu(de->rec_len);
591 			if (le64_to_cpu(de->inode)) {
592 				de1 = (struct ocfs2_dir_entry *)((char *) de +
593 					OCFS2_DIR_REC_LEN(de->name_len));
594 				de1->rec_len =
595 					cpu_to_le16(le16_to_cpu(de->rec_len) -
596 					OCFS2_DIR_REC_LEN(de->name_len));
597 				de->rec_len = cpu_to_le16(OCFS2_DIR_REC_LEN(de->name_len));
598 				de = de1;
599 			}
600 			de->file_type = OCFS2_FT_UNKNOWN;
601 			if (blkno) {
602 				de->inode = cpu_to_le64(blkno);
603 				ocfs2_set_de_type(de, inode->i_mode);
604 			} else
605 				de->inode = 0;
606 			de->name_len = namelen;
607 			memcpy(de->name, name, namelen);
608 
609 			dir->i_version++;
610 			status = ocfs2_journal_dirty(handle, insert_bh);
611 			retval = 0;
612 			goto bail;
613 		}
614 		offset += le16_to_cpu(de->rec_len);
615 		de = (struct ocfs2_dir_entry *) ((char *) de + le16_to_cpu(de->rec_len));
616 	}
617 
618 	/* when you think about it, the assert above should prevent us
619 	 * from ever getting here. */
620 	retval = -ENOSPC;
621 bail:
622 
623 	mlog_exit(retval);
624 	return retval;
625 }
626 
627 static int ocfs2_dir_foreach_blk_id(struct inode *inode,
628 				    u64 *f_version,
629 				    loff_t *f_pos, void *priv,
630 				    filldir_t filldir, int *filldir_err)
631 {
632 	int ret, i, filldir_ret;
633 	unsigned long offset = *f_pos;
634 	struct buffer_head *di_bh = NULL;
635 	struct ocfs2_dinode *di;
636 	struct ocfs2_inline_data *data;
637 	struct ocfs2_dir_entry *de;
638 
639 	ret = ocfs2_read_block(inode, OCFS2_I(inode)->ip_blkno, &di_bh);
640 	if (ret) {
641 		mlog(ML_ERROR, "Unable to read inode block for dir %llu\n",
642 		     (unsigned long long)OCFS2_I(inode)->ip_blkno);
643 		goto out;
644 	}
645 
646 	di = (struct ocfs2_dinode *)di_bh->b_data;
647 	data = &di->id2.i_data;
648 
649 	while (*f_pos < i_size_read(inode)) {
650 revalidate:
651 		/* If the dir block has changed since the last call to
652 		 * readdir(2), then we might be pointing to an invalid
653 		 * dirent right now.  Scan from the start of the block
654 		 * to make sure. */
655 		if (*f_version != inode->i_version) {
656 			for (i = 0; i < i_size_read(inode) && i < offset; ) {
657 				de = (struct ocfs2_dir_entry *)
658 					(data->id_data + i);
659 				/* It's too expensive to do a full
660 				 * dirent test each time round this
661 				 * loop, but we do have to test at
662 				 * least that it is non-zero.  A
663 				 * failure will be detected in the
664 				 * dirent test below. */
665 				if (le16_to_cpu(de->rec_len) <
666 				    OCFS2_DIR_REC_LEN(1))
667 					break;
668 				i += le16_to_cpu(de->rec_len);
669 			}
670 			*f_pos = offset = i;
671 			*f_version = inode->i_version;
672 		}
673 
674 		de = (struct ocfs2_dir_entry *) (data->id_data + *f_pos);
675 		if (!ocfs2_check_dir_entry(inode, de, di_bh, *f_pos)) {
676 			/* On error, skip the f_pos to the end. */
677 			*f_pos = i_size_read(inode);
678 			goto out;
679 		}
680 		offset += le16_to_cpu(de->rec_len);
681 		if (le64_to_cpu(de->inode)) {
682 			/* We might block in the next section
683 			 * if the data destination is
684 			 * currently swapped out.  So, use a
685 			 * version stamp to detect whether or
686 			 * not the directory has been modified
687 			 * during the copy operation.
688 			 */
689 			u64 version = *f_version;
690 			unsigned char d_type = DT_UNKNOWN;
691 
692 			if (de->file_type < OCFS2_FT_MAX)
693 				d_type = ocfs2_filetype_table[de->file_type];
694 
695 			filldir_ret = filldir(priv, de->name,
696 					      de->name_len,
697 					      *f_pos,
698 					      le64_to_cpu(de->inode),
699 					      d_type);
700 			if (filldir_ret) {
701 				if (filldir_err)
702 					*filldir_err = filldir_ret;
703 				break;
704 			}
705 			if (version != *f_version)
706 				goto revalidate;
707 		}
708 		*f_pos += le16_to_cpu(de->rec_len);
709 	}
710 
711 out:
712 	brelse(di_bh);
713 
714 	return 0;
715 }
716 
717 static int ocfs2_dir_foreach_blk_el(struct inode *inode,
718 				    u64 *f_version,
719 				    loff_t *f_pos, void *priv,
720 				    filldir_t filldir, int *filldir_err)
721 {
722 	int error = 0;
723 	unsigned long offset, blk, last_ra_blk = 0;
724 	int i, stored;
725 	struct buffer_head * bh, * tmp;
726 	struct ocfs2_dir_entry * de;
727 	int err;
728 	struct super_block * sb = inode->i_sb;
729 	unsigned int ra_sectors = 16;
730 
731 	stored = 0;
732 	bh = NULL;
733 
734 	offset = (*f_pos) & (sb->s_blocksize - 1);
735 
736 	while (!error && !stored && *f_pos < i_size_read(inode)) {
737 		blk = (*f_pos) >> sb->s_blocksize_bits;
738 		bh = ocfs2_bread(inode, blk, &err, 0);
739 		if (!bh) {
740 			mlog(ML_ERROR,
741 			     "directory #%llu contains a hole at offset %lld\n",
742 			     (unsigned long long)OCFS2_I(inode)->ip_blkno,
743 			     *f_pos);
744 			*f_pos += sb->s_blocksize - offset;
745 			continue;
746 		}
747 
748 		/* The idea here is to begin with 8k read-ahead and to stay
749 		 * 4k ahead of our current position.
750 		 *
751 		 * TODO: Use the pagecache for this. We just need to
752 		 * make sure it's cluster-safe... */
753 		if (!last_ra_blk
754 		    || (((last_ra_blk - blk) << 9) <= (ra_sectors / 2))) {
755 			for (i = ra_sectors >> (sb->s_blocksize_bits - 9);
756 			     i > 0; i--) {
757 				tmp = ocfs2_bread(inode, ++blk, &err, 1);
758 				brelse(tmp);
759 			}
760 			last_ra_blk = blk;
761 			ra_sectors = 8;
762 		}
763 
764 revalidate:
765 		/* If the dir block has changed since the last call to
766 		 * readdir(2), then we might be pointing to an invalid
767 		 * dirent right now.  Scan from the start of the block
768 		 * to make sure. */
769 		if (*f_version != inode->i_version) {
770 			for (i = 0; i < sb->s_blocksize && i < offset; ) {
771 				de = (struct ocfs2_dir_entry *) (bh->b_data + i);
772 				/* It's too expensive to do a full
773 				 * dirent test each time round this
774 				 * loop, but we do have to test at
775 				 * least that it is non-zero.  A
776 				 * failure will be detected in the
777 				 * dirent test below. */
778 				if (le16_to_cpu(de->rec_len) <
779 				    OCFS2_DIR_REC_LEN(1))
780 					break;
781 				i += le16_to_cpu(de->rec_len);
782 			}
783 			offset = i;
784 			*f_pos = ((*f_pos) & ~(sb->s_blocksize - 1))
785 				| offset;
786 			*f_version = inode->i_version;
787 		}
788 
789 		while (!error && *f_pos < i_size_read(inode)
790 		       && offset < sb->s_blocksize) {
791 			de = (struct ocfs2_dir_entry *) (bh->b_data + offset);
792 			if (!ocfs2_check_dir_entry(inode, de, bh, offset)) {
793 				/* On error, skip the f_pos to the
794 				   next block. */
795 				*f_pos = ((*f_pos) | (sb->s_blocksize - 1)) + 1;
796 				brelse(bh);
797 				goto out;
798 			}
799 			offset += le16_to_cpu(de->rec_len);
800 			if (le64_to_cpu(de->inode)) {
801 				/* We might block in the next section
802 				 * if the data destination is
803 				 * currently swapped out.  So, use a
804 				 * version stamp to detect whether or
805 				 * not the directory has been modified
806 				 * during the copy operation.
807 				 */
808 				unsigned long version = *f_version;
809 				unsigned char d_type = DT_UNKNOWN;
810 
811 				if (de->file_type < OCFS2_FT_MAX)
812 					d_type = ocfs2_filetype_table[de->file_type];
813 				error = filldir(priv, de->name,
814 						de->name_len,
815 						*f_pos,
816 						le64_to_cpu(de->inode),
817 						d_type);
818 				if (error) {
819 					if (filldir_err)
820 						*filldir_err = error;
821 					break;
822 				}
823 				if (version != *f_version)
824 					goto revalidate;
825 				stored ++;
826 			}
827 			*f_pos += le16_to_cpu(de->rec_len);
828 		}
829 		offset = 0;
830 		brelse(bh);
831 	}
832 
833 	stored = 0;
834 out:
835 	return stored;
836 }
837 
838 static int ocfs2_dir_foreach_blk(struct inode *inode, u64 *f_version,
839 				 loff_t *f_pos, void *priv, filldir_t filldir,
840 				 int *filldir_err)
841 {
842 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
843 		return ocfs2_dir_foreach_blk_id(inode, f_version, f_pos, priv,
844 						filldir, filldir_err);
845 
846 	return ocfs2_dir_foreach_blk_el(inode, f_version, f_pos, priv, filldir,
847 					filldir_err);
848 }
849 
850 /*
851  * This is intended to be called from inside other kernel functions,
852  * so we fake some arguments.
853  */
854 int ocfs2_dir_foreach(struct inode *inode, loff_t *f_pos, void *priv,
855 		      filldir_t filldir)
856 {
857 	int ret = 0, filldir_err = 0;
858 	u64 version = inode->i_version;
859 
860 	while (*f_pos < i_size_read(inode)) {
861 		ret = ocfs2_dir_foreach_blk(inode, &version, f_pos, priv,
862 					    filldir, &filldir_err);
863 		if (ret || filldir_err)
864 			break;
865 	}
866 
867 	if (ret > 0)
868 		ret = -EIO;
869 
870 	return 0;
871 }
872 
873 /*
874  * ocfs2_readdir()
875  *
876  */
877 int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir)
878 {
879 	int error = 0;
880 	struct inode *inode = filp->f_path.dentry->d_inode;
881 	int lock_level = 0;
882 
883 	mlog_entry("dirino=%llu\n",
884 		   (unsigned long long)OCFS2_I(inode)->ip_blkno);
885 
886 	error = ocfs2_inode_lock_atime(inode, filp->f_vfsmnt, &lock_level);
887 	if (lock_level && error >= 0) {
888 		/* We release EX lock which used to update atime
889 		 * and get PR lock again to reduce contention
890 		 * on commonly accessed directories. */
891 		ocfs2_inode_unlock(inode, 1);
892 		lock_level = 0;
893 		error = ocfs2_inode_lock(inode, NULL, 0);
894 	}
895 	if (error < 0) {
896 		if (error != -ENOENT)
897 			mlog_errno(error);
898 		/* we haven't got any yet, so propagate the error. */
899 		goto bail_nolock;
900 	}
901 
902 	error = ocfs2_dir_foreach_blk(inode, &filp->f_version, &filp->f_pos,
903 				      dirent, filldir, NULL);
904 
905 	ocfs2_inode_unlock(inode, lock_level);
906 
907 bail_nolock:
908 	mlog_exit(error);
909 
910 	return error;
911 }
912 
913 /*
914  * NOTE: this should always be called with parent dir i_mutex taken.
915  */
916 int ocfs2_find_files_on_disk(const char *name,
917 			     int namelen,
918 			     u64 *blkno,
919 			     struct inode *inode,
920 			     struct buffer_head **dirent_bh,
921 			     struct ocfs2_dir_entry **dirent)
922 {
923 	int status = -ENOENT;
924 
925 	mlog_entry("(name=%.*s, blkno=%p, inode=%p, dirent_bh=%p, dirent=%p)\n",
926 		   namelen, name, blkno, inode, dirent_bh, dirent);
927 
928 	*dirent_bh = ocfs2_find_entry(name, namelen, inode, dirent);
929 	if (!*dirent_bh || !*dirent) {
930 		status = -ENOENT;
931 		goto leave;
932 	}
933 
934 	*blkno = le64_to_cpu((*dirent)->inode);
935 
936 	status = 0;
937 leave:
938 	if (status < 0) {
939 		*dirent = NULL;
940 		brelse(*dirent_bh);
941 		*dirent_bh = NULL;
942 	}
943 
944 	mlog_exit(status);
945 	return status;
946 }
947 
948 /*
949  * Convenience function for callers which just want the block number
950  * mapped to a name and don't require the full dirent info, etc.
951  */
952 int ocfs2_lookup_ino_from_name(struct inode *dir, const char *name,
953 			       int namelen, u64 *blkno)
954 {
955 	int ret;
956 	struct buffer_head *bh = NULL;
957 	struct ocfs2_dir_entry *dirent = NULL;
958 
959 	ret = ocfs2_find_files_on_disk(name, namelen, blkno, dir, &bh, &dirent);
960 	brelse(bh);
961 
962 	return ret;
963 }
964 
965 /* Check for a name within a directory.
966  *
967  * Return 0 if the name does not exist
968  * Return -EEXIST if the directory contains the name
969  *
970  * Callers should have i_mutex + a cluster lock on dir
971  */
972 int ocfs2_check_dir_for_entry(struct inode *dir,
973 			      const char *name,
974 			      int namelen)
975 {
976 	int ret;
977 	struct buffer_head *dirent_bh = NULL;
978 	struct ocfs2_dir_entry *dirent = NULL;
979 
980 	mlog_entry("dir %llu, name '%.*s'\n",
981 		   (unsigned long long)OCFS2_I(dir)->ip_blkno, namelen, name);
982 
983 	ret = -EEXIST;
984 	dirent_bh = ocfs2_find_entry(name, namelen, dir, &dirent);
985 	if (dirent_bh)
986 		goto bail;
987 
988 	ret = 0;
989 bail:
990 	brelse(dirent_bh);
991 
992 	mlog_exit(ret);
993 	return ret;
994 }
995 
996 struct ocfs2_empty_dir_priv {
997 	unsigned seen_dot;
998 	unsigned seen_dot_dot;
999 	unsigned seen_other;
1000 };
1001 static int ocfs2_empty_dir_filldir(void *priv, const char *name, int name_len,
1002 				   loff_t pos, u64 ino, unsigned type)
1003 {
1004 	struct ocfs2_empty_dir_priv *p = priv;
1005 
1006 	/*
1007 	 * Check the positions of "." and ".." records to be sure
1008 	 * they're in the correct place.
1009 	 */
1010 	if (name_len == 1 && !strncmp(".", name, 1) && pos == 0) {
1011 		p->seen_dot = 1;
1012 		return 0;
1013 	}
1014 
1015 	if (name_len == 2 && !strncmp("..", name, 2) &&
1016 	    pos == OCFS2_DIR_REC_LEN(1)) {
1017 		p->seen_dot_dot = 1;
1018 		return 0;
1019 	}
1020 
1021 	p->seen_other = 1;
1022 	return 1;
1023 }
1024 /*
1025  * routine to check that the specified directory is empty (for rmdir)
1026  *
1027  * Returns 1 if dir is empty, zero otherwise.
1028  */
1029 int ocfs2_empty_dir(struct inode *inode)
1030 {
1031 	int ret;
1032 	loff_t start = 0;
1033 	struct ocfs2_empty_dir_priv priv;
1034 
1035 	memset(&priv, 0, sizeof(priv));
1036 
1037 	ret = ocfs2_dir_foreach(inode, &start, &priv, ocfs2_empty_dir_filldir);
1038 	if (ret)
1039 		mlog_errno(ret);
1040 
1041 	if (!priv.seen_dot || !priv.seen_dot_dot) {
1042 		mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n",
1043 		     (unsigned long long)OCFS2_I(inode)->ip_blkno);
1044 		/*
1045 		 * XXX: Is it really safe to allow an unlink to continue?
1046 		 */
1047 		return 1;
1048 	}
1049 
1050 	return !priv.seen_other;
1051 }
1052 
1053 static void ocfs2_fill_initial_dirents(struct inode *inode,
1054 				       struct inode *parent,
1055 				       char *start, unsigned int size)
1056 {
1057 	struct ocfs2_dir_entry *de = (struct ocfs2_dir_entry *)start;
1058 
1059 	de->inode = cpu_to_le64(OCFS2_I(inode)->ip_blkno);
1060 	de->name_len = 1;
1061 	de->rec_len =
1062 		cpu_to_le16(OCFS2_DIR_REC_LEN(de->name_len));
1063 	strcpy(de->name, ".");
1064 	ocfs2_set_de_type(de, S_IFDIR);
1065 
1066 	de = (struct ocfs2_dir_entry *) ((char *)de + le16_to_cpu(de->rec_len));
1067 	de->inode = cpu_to_le64(OCFS2_I(parent)->ip_blkno);
1068 	de->rec_len = cpu_to_le16(size - OCFS2_DIR_REC_LEN(1));
1069 	de->name_len = 2;
1070 	strcpy(de->name, "..");
1071 	ocfs2_set_de_type(de, S_IFDIR);
1072 }
1073 
1074 /*
1075  * This works together with code in ocfs2_mknod_locked() which sets
1076  * the inline-data flag and initializes the inline-data section.
1077  */
1078 static int ocfs2_fill_new_dir_id(struct ocfs2_super *osb,
1079 				 handle_t *handle,
1080 				 struct inode *parent,
1081 				 struct inode *inode,
1082 				 struct buffer_head *di_bh)
1083 {
1084 	int ret;
1085 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1086 	struct ocfs2_inline_data *data = &di->id2.i_data;
1087 	unsigned int size = le16_to_cpu(data->id_count);
1088 
1089 	ret = ocfs2_journal_access(handle, inode, di_bh,
1090 				   OCFS2_JOURNAL_ACCESS_WRITE);
1091 	if (ret) {
1092 		mlog_errno(ret);
1093 		goto out;
1094 	}
1095 
1096 	ocfs2_fill_initial_dirents(inode, parent, data->id_data, size);
1097 
1098 	ocfs2_journal_dirty(handle, di_bh);
1099 	if (ret) {
1100 		mlog_errno(ret);
1101 		goto out;
1102 	}
1103 
1104 	i_size_write(inode, size);
1105 	inode->i_nlink = 2;
1106 	inode->i_blocks = ocfs2_inode_sector_count(inode);
1107 
1108 	ret = ocfs2_mark_inode_dirty(handle, inode, di_bh);
1109 	if (ret < 0)
1110 		mlog_errno(ret);
1111 
1112 out:
1113 	return ret;
1114 }
1115 
1116 static int ocfs2_fill_new_dir_el(struct ocfs2_super *osb,
1117 				 handle_t *handle,
1118 				 struct inode *parent,
1119 				 struct inode *inode,
1120 				 struct buffer_head *fe_bh,
1121 				 struct ocfs2_alloc_context *data_ac)
1122 {
1123 	int status;
1124 	struct buffer_head *new_bh = NULL;
1125 
1126 	mlog_entry_void();
1127 
1128 	status = ocfs2_do_extend_dir(osb->sb, handle, inode, fe_bh,
1129 				     data_ac, NULL, &new_bh);
1130 	if (status < 0) {
1131 		mlog_errno(status);
1132 		goto bail;
1133 	}
1134 
1135 	ocfs2_set_new_buffer_uptodate(inode, new_bh);
1136 
1137 	status = ocfs2_journal_access(handle, inode, new_bh,
1138 				      OCFS2_JOURNAL_ACCESS_CREATE);
1139 	if (status < 0) {
1140 		mlog_errno(status);
1141 		goto bail;
1142 	}
1143 	memset(new_bh->b_data, 0, osb->sb->s_blocksize);
1144 
1145 	ocfs2_fill_initial_dirents(inode, parent, new_bh->b_data,
1146 				   osb->sb->s_blocksize);
1147 
1148 	status = ocfs2_journal_dirty(handle, new_bh);
1149 	if (status < 0) {
1150 		mlog_errno(status);
1151 		goto bail;
1152 	}
1153 
1154 	i_size_write(inode, inode->i_sb->s_blocksize);
1155 	inode->i_nlink = 2;
1156 	inode->i_blocks = ocfs2_inode_sector_count(inode);
1157 	status = ocfs2_mark_inode_dirty(handle, inode, fe_bh);
1158 	if (status < 0) {
1159 		mlog_errno(status);
1160 		goto bail;
1161 	}
1162 
1163 	status = 0;
1164 bail:
1165 	brelse(new_bh);
1166 
1167 	mlog_exit(status);
1168 	return status;
1169 }
1170 
1171 int ocfs2_fill_new_dir(struct ocfs2_super *osb,
1172 		       handle_t *handle,
1173 		       struct inode *parent,
1174 		       struct inode *inode,
1175 		       struct buffer_head *fe_bh,
1176 		       struct ocfs2_alloc_context *data_ac)
1177 {
1178 	BUG_ON(!ocfs2_supports_inline_data(osb) && data_ac == NULL);
1179 
1180 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
1181 		return ocfs2_fill_new_dir_id(osb, handle, parent, inode, fe_bh);
1182 
1183 	return ocfs2_fill_new_dir_el(osb, handle, parent, inode, fe_bh,
1184 				     data_ac);
1185 }
1186 
1187 static void ocfs2_expand_last_dirent(char *start, unsigned int old_size,
1188 				     unsigned int new_size)
1189 {
1190 	struct ocfs2_dir_entry *de;
1191 	struct ocfs2_dir_entry *prev_de;
1192 	char *de_buf, *limit;
1193 	unsigned int bytes = new_size - old_size;
1194 
1195 	limit = start + old_size;
1196 	de_buf = start;
1197 	de = (struct ocfs2_dir_entry *)de_buf;
1198 	do {
1199 		prev_de = de;
1200 		de_buf += le16_to_cpu(de->rec_len);
1201 		de = (struct ocfs2_dir_entry *)de_buf;
1202 	} while (de_buf < limit);
1203 
1204 	le16_add_cpu(&prev_de->rec_len, bytes);
1205 }
1206 
1207 /*
1208  * We allocate enough clusters to fulfill "blocks_wanted", but set
1209  * i_size to exactly one block. Ocfs2_extend_dir() will handle the
1210  * rest automatically for us.
1211  *
1212  * *first_block_bh is a pointer to the 1st data block allocated to the
1213  *  directory.
1214  */
1215 static int ocfs2_expand_inline_dir(struct inode *dir, struct buffer_head *di_bh,
1216 				   unsigned int blocks_wanted,
1217 				   struct buffer_head **first_block_bh)
1218 {
1219 	int ret, credits = OCFS2_INLINE_TO_EXTENTS_CREDITS;
1220 	u32 alloc, bit_off, len;
1221 	struct super_block *sb = dir->i_sb;
1222 	u64 blkno, bytes = blocks_wanted << sb->s_blocksize_bits;
1223 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
1224 	struct ocfs2_inode_info *oi = OCFS2_I(dir);
1225 	struct ocfs2_alloc_context *data_ac;
1226 	struct buffer_head *dirdata_bh = NULL;
1227 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1228 	handle_t *handle;
1229 	struct ocfs2_extent_tree et;
1230 
1231 	ocfs2_init_dinode_extent_tree(&et, dir, di_bh);
1232 
1233 	alloc = ocfs2_clusters_for_bytes(sb, bytes);
1234 
1235 	/*
1236 	 * We should never need more than 2 clusters for this -
1237 	 * maximum dirent size is far less than one block. In fact,
1238 	 * the only time we'd need more than one cluster is if
1239 	 * blocksize == clustersize and the dirent won't fit in the
1240 	 * extra space that the expansion to a single block gives. As
1241 	 * of today, that only happens on 4k/4k file systems.
1242 	 */
1243 	BUG_ON(alloc > 2);
1244 
1245 	ret = ocfs2_reserve_clusters(osb, alloc, &data_ac);
1246 	if (ret) {
1247 		mlog_errno(ret);
1248 		goto out;
1249 	}
1250 
1251 	down_write(&oi->ip_alloc_sem);
1252 
1253 	/*
1254 	 * Prepare for worst case allocation scenario of two separate
1255 	 * extents.
1256 	 */
1257 	if (alloc == 2)
1258 		credits += OCFS2_SUBALLOC_ALLOC;
1259 
1260 	handle = ocfs2_start_trans(osb, credits);
1261 	if (IS_ERR(handle)) {
1262 		ret = PTR_ERR(handle);
1263 		mlog_errno(ret);
1264 		goto out_sem;
1265 	}
1266 
1267 	/*
1268 	 * Try to claim as many clusters as the bitmap can give though
1269 	 * if we only get one now, that's enough to continue. The rest
1270 	 * will be claimed after the conversion to extents.
1271 	 */
1272 	ret = ocfs2_claim_clusters(osb, handle, data_ac, 1, &bit_off, &len);
1273 	if (ret) {
1274 		mlog_errno(ret);
1275 		goto out_commit;
1276 	}
1277 
1278 	/*
1279 	 * Operations are carefully ordered so that we set up the new
1280 	 * data block first. The conversion from inline data to
1281 	 * extents follows.
1282 	 */
1283 	blkno = ocfs2_clusters_to_blocks(dir->i_sb, bit_off);
1284 	dirdata_bh = sb_getblk(sb, blkno);
1285 	if (!dirdata_bh) {
1286 		ret = -EIO;
1287 		mlog_errno(ret);
1288 		goto out_commit;
1289 	}
1290 
1291 	ocfs2_set_new_buffer_uptodate(dir, dirdata_bh);
1292 
1293 	ret = ocfs2_journal_access(handle, dir, dirdata_bh,
1294 				   OCFS2_JOURNAL_ACCESS_CREATE);
1295 	if (ret) {
1296 		mlog_errno(ret);
1297 		goto out_commit;
1298 	}
1299 
1300 	memcpy(dirdata_bh->b_data, di->id2.i_data.id_data, i_size_read(dir));
1301 	memset(dirdata_bh->b_data + i_size_read(dir), 0,
1302 	       sb->s_blocksize - i_size_read(dir));
1303 	ocfs2_expand_last_dirent(dirdata_bh->b_data, i_size_read(dir),
1304 				 sb->s_blocksize);
1305 
1306 	ret = ocfs2_journal_dirty(handle, dirdata_bh);
1307 	if (ret) {
1308 		mlog_errno(ret);
1309 		goto out_commit;
1310 	}
1311 
1312 	/*
1313 	 * Set extent, i_size, etc on the directory. After this, the
1314 	 * inode should contain the same exact dirents as before and
1315 	 * be fully accessible from system calls.
1316 	 *
1317 	 * We let the later dirent insert modify c/mtime - to the user
1318 	 * the data hasn't changed.
1319 	 */
1320 	ret = ocfs2_journal_access(handle, dir, di_bh,
1321 				   OCFS2_JOURNAL_ACCESS_CREATE);
1322 	if (ret) {
1323 		mlog_errno(ret);
1324 		goto out_commit;
1325 	}
1326 
1327 	spin_lock(&oi->ip_lock);
1328 	oi->ip_dyn_features &= ~OCFS2_INLINE_DATA_FL;
1329 	di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
1330 	spin_unlock(&oi->ip_lock);
1331 
1332 	ocfs2_dinode_new_extent_list(dir, di);
1333 
1334 	i_size_write(dir, sb->s_blocksize);
1335 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
1336 
1337 	di->i_size = cpu_to_le64(sb->s_blocksize);
1338 	di->i_ctime = di->i_mtime = cpu_to_le64(dir->i_ctime.tv_sec);
1339 	di->i_ctime_nsec = di->i_mtime_nsec = cpu_to_le32(dir->i_ctime.tv_nsec);
1340 
1341 	/*
1342 	 * This should never fail as our extent list is empty and all
1343 	 * related blocks have been journaled already.
1344 	 */
1345 	ret = ocfs2_insert_extent(osb, handle, dir, &et, 0, blkno, len,
1346 				  0, NULL);
1347 	if (ret) {
1348 		mlog_errno(ret);
1349 		goto out_commit;
1350 	}
1351 
1352 	/*
1353 	 * Set i_blocks after the extent insert for the most up to
1354 	 * date ip_clusters value.
1355 	 */
1356 	dir->i_blocks = ocfs2_inode_sector_count(dir);
1357 
1358 	ret = ocfs2_journal_dirty(handle, di_bh);
1359 	if (ret) {
1360 		mlog_errno(ret);
1361 		goto out_commit;
1362 	}
1363 
1364 	/*
1365 	 * We asked for two clusters, but only got one in the 1st
1366 	 * pass. Claim the 2nd cluster as a separate extent.
1367 	 */
1368 	if (alloc > len) {
1369 		ret = ocfs2_claim_clusters(osb, handle, data_ac, 1, &bit_off,
1370 					   &len);
1371 		if (ret) {
1372 			mlog_errno(ret);
1373 			goto out_commit;
1374 		}
1375 		blkno = ocfs2_clusters_to_blocks(dir->i_sb, bit_off);
1376 
1377 		ret = ocfs2_insert_extent(osb, handle, dir, &et, 1,
1378 					  blkno, len, 0, NULL);
1379 		if (ret) {
1380 			mlog_errno(ret);
1381 			goto out_commit;
1382 		}
1383 	}
1384 
1385 	*first_block_bh = dirdata_bh;
1386 	dirdata_bh = NULL;
1387 
1388 out_commit:
1389 	ocfs2_commit_trans(osb, handle);
1390 
1391 out_sem:
1392 	up_write(&oi->ip_alloc_sem);
1393 
1394 out:
1395 	if (data_ac)
1396 		ocfs2_free_alloc_context(data_ac);
1397 
1398 	brelse(dirdata_bh);
1399 
1400 	return ret;
1401 }
1402 
1403 /* returns a bh of the 1st new block in the allocation. */
1404 static int ocfs2_do_extend_dir(struct super_block *sb,
1405 			       handle_t *handle,
1406 			       struct inode *dir,
1407 			       struct buffer_head *parent_fe_bh,
1408 			       struct ocfs2_alloc_context *data_ac,
1409 			       struct ocfs2_alloc_context *meta_ac,
1410 			       struct buffer_head **new_bh)
1411 {
1412 	int status;
1413 	int extend;
1414 	u64 p_blkno, v_blkno;
1415 
1416 	spin_lock(&OCFS2_I(dir)->ip_lock);
1417 	extend = (i_size_read(dir) == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters));
1418 	spin_unlock(&OCFS2_I(dir)->ip_lock);
1419 
1420 	if (extend) {
1421 		u32 offset = OCFS2_I(dir)->ip_clusters;
1422 
1423 		status = ocfs2_add_inode_data(OCFS2_SB(sb), dir, &offset,
1424 					      1, 0, parent_fe_bh, handle,
1425 					      data_ac, meta_ac, NULL);
1426 		BUG_ON(status == -EAGAIN);
1427 		if (status < 0) {
1428 			mlog_errno(status);
1429 			goto bail;
1430 		}
1431 	}
1432 
1433 	v_blkno = ocfs2_blocks_for_bytes(sb, i_size_read(dir));
1434 	status = ocfs2_extent_map_get_blocks(dir, v_blkno, &p_blkno, NULL, NULL);
1435 	if (status < 0) {
1436 		mlog_errno(status);
1437 		goto bail;
1438 	}
1439 
1440 	*new_bh = sb_getblk(sb, p_blkno);
1441 	if (!*new_bh) {
1442 		status = -EIO;
1443 		mlog_errno(status);
1444 		goto bail;
1445 	}
1446 	status = 0;
1447 bail:
1448 	mlog_exit(status);
1449 	return status;
1450 }
1451 
1452 /*
1453  * Assumes you already have a cluster lock on the directory.
1454  *
1455  * 'blocks_wanted' is only used if we have an inline directory which
1456  * is to be turned into an extent based one. The size of the dirent to
1457  * insert might be larger than the space gained by growing to just one
1458  * block, so we may have to grow the inode by two blocks in that case.
1459  */
1460 static int ocfs2_extend_dir(struct ocfs2_super *osb,
1461 			    struct inode *dir,
1462 			    struct buffer_head *parent_fe_bh,
1463 			    unsigned int blocks_wanted,
1464 			    struct buffer_head **new_de_bh)
1465 {
1466 	int status = 0;
1467 	int credits, num_free_extents, drop_alloc_sem = 0;
1468 	loff_t dir_i_size;
1469 	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
1470 	struct ocfs2_extent_list *el = &fe->id2.i_list;
1471 	struct ocfs2_alloc_context *data_ac = NULL;
1472 	struct ocfs2_alloc_context *meta_ac = NULL;
1473 	handle_t *handle = NULL;
1474 	struct buffer_head *new_bh = NULL;
1475 	struct ocfs2_dir_entry * de;
1476 	struct super_block *sb = osb->sb;
1477 	struct ocfs2_extent_tree et;
1478 
1479 	mlog_entry_void();
1480 
1481 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1482 		status = ocfs2_expand_inline_dir(dir, parent_fe_bh,
1483 						 blocks_wanted, &new_bh);
1484 		if (status) {
1485 			mlog_errno(status);
1486 			goto bail;
1487 		}
1488 
1489 		if (blocks_wanted == 1) {
1490 			/*
1491 			 * If the new dirent will fit inside the space
1492 			 * created by pushing out to one block, then
1493 			 * we can complete the operation
1494 			 * here. Otherwise we have to expand i_size
1495 			 * and format the 2nd block below.
1496 			 */
1497 			BUG_ON(new_bh == NULL);
1498 			goto bail_bh;
1499 		}
1500 
1501 		/*
1502 		 * Get rid of 'new_bh' - we want to format the 2nd
1503 		 * data block and return that instead.
1504 		 */
1505 		brelse(new_bh);
1506 		new_bh = NULL;
1507 
1508 		dir_i_size = i_size_read(dir);
1509 		credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS;
1510 		goto do_extend;
1511 	}
1512 
1513 	dir_i_size = i_size_read(dir);
1514 	mlog(0, "extending dir %llu (i_size = %lld)\n",
1515 	     (unsigned long long)OCFS2_I(dir)->ip_blkno, dir_i_size);
1516 
1517 	/* dir->i_size is always block aligned. */
1518 	spin_lock(&OCFS2_I(dir)->ip_lock);
1519 	if (dir_i_size == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)) {
1520 		spin_unlock(&OCFS2_I(dir)->ip_lock);
1521 		ocfs2_init_dinode_extent_tree(&et, dir, parent_fe_bh);
1522 		num_free_extents = ocfs2_num_free_extents(osb, dir, &et);
1523 		if (num_free_extents < 0) {
1524 			status = num_free_extents;
1525 			mlog_errno(status);
1526 			goto bail;
1527 		}
1528 
1529 		if (!num_free_extents) {
1530 			status = ocfs2_reserve_new_metadata(osb, el, &meta_ac);
1531 			if (status < 0) {
1532 				if (status != -ENOSPC)
1533 					mlog_errno(status);
1534 				goto bail;
1535 			}
1536 		}
1537 
1538 		status = ocfs2_reserve_clusters(osb, 1, &data_ac);
1539 		if (status < 0) {
1540 			if (status != -ENOSPC)
1541 				mlog_errno(status);
1542 			goto bail;
1543 		}
1544 
1545 		credits = ocfs2_calc_extend_credits(sb, el, 1);
1546 	} else {
1547 		spin_unlock(&OCFS2_I(dir)->ip_lock);
1548 		credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS;
1549 	}
1550 
1551 do_extend:
1552 	down_write(&OCFS2_I(dir)->ip_alloc_sem);
1553 	drop_alloc_sem = 1;
1554 
1555 	handle = ocfs2_start_trans(osb, credits);
1556 	if (IS_ERR(handle)) {
1557 		status = PTR_ERR(handle);
1558 		handle = NULL;
1559 		mlog_errno(status);
1560 		goto bail;
1561 	}
1562 
1563 	status = ocfs2_do_extend_dir(osb->sb, handle, dir, parent_fe_bh,
1564 				     data_ac, meta_ac, &new_bh);
1565 	if (status < 0) {
1566 		mlog_errno(status);
1567 		goto bail;
1568 	}
1569 
1570 	ocfs2_set_new_buffer_uptodate(dir, new_bh);
1571 
1572 	status = ocfs2_journal_access(handle, dir, new_bh,
1573 				      OCFS2_JOURNAL_ACCESS_CREATE);
1574 	if (status < 0) {
1575 		mlog_errno(status);
1576 		goto bail;
1577 	}
1578 	memset(new_bh->b_data, 0, sb->s_blocksize);
1579 	de = (struct ocfs2_dir_entry *) new_bh->b_data;
1580 	de->inode = 0;
1581 	de->rec_len = cpu_to_le16(sb->s_blocksize);
1582 	status = ocfs2_journal_dirty(handle, new_bh);
1583 	if (status < 0) {
1584 		mlog_errno(status);
1585 		goto bail;
1586 	}
1587 
1588 	dir_i_size += dir->i_sb->s_blocksize;
1589 	i_size_write(dir, dir_i_size);
1590 	dir->i_blocks = ocfs2_inode_sector_count(dir);
1591 	status = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh);
1592 	if (status < 0) {
1593 		mlog_errno(status);
1594 		goto bail;
1595 	}
1596 
1597 bail_bh:
1598 	*new_de_bh = new_bh;
1599 	get_bh(*new_de_bh);
1600 bail:
1601 	if (drop_alloc_sem)
1602 		up_write(&OCFS2_I(dir)->ip_alloc_sem);
1603 	if (handle)
1604 		ocfs2_commit_trans(osb, handle);
1605 
1606 	if (data_ac)
1607 		ocfs2_free_alloc_context(data_ac);
1608 	if (meta_ac)
1609 		ocfs2_free_alloc_context(meta_ac);
1610 
1611 	brelse(new_bh);
1612 
1613 	mlog_exit(status);
1614 	return status;
1615 }
1616 
1617 static int ocfs2_find_dir_space_id(struct inode *dir, struct buffer_head *di_bh,
1618 				   const char *name, int namelen,
1619 				   struct buffer_head **ret_de_bh,
1620 				   unsigned int *blocks_wanted)
1621 {
1622 	int ret;
1623 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1624 	struct ocfs2_dir_entry *de, *last_de = NULL;
1625 	char *de_buf, *limit;
1626 	unsigned long offset = 0;
1627 	unsigned int rec_len, new_rec_len;
1628 
1629 	de_buf = di->id2.i_data.id_data;
1630 	limit = de_buf + i_size_read(dir);
1631 	rec_len = OCFS2_DIR_REC_LEN(namelen);
1632 
1633 	while (de_buf < limit) {
1634 		de = (struct ocfs2_dir_entry *)de_buf;
1635 
1636 		if (!ocfs2_check_dir_entry(dir, de, di_bh, offset)) {
1637 			ret = -ENOENT;
1638 			goto out;
1639 		}
1640 		if (ocfs2_match(namelen, name, de)) {
1641 			ret = -EEXIST;
1642 			goto out;
1643 		}
1644 		if (ocfs2_dirent_would_fit(de, rec_len)) {
1645 			/* Ok, we found a spot. Return this bh and let
1646 			 * the caller actually fill it in. */
1647 			*ret_de_bh = di_bh;
1648 			get_bh(*ret_de_bh);
1649 			ret = 0;
1650 			goto out;
1651 		}
1652 
1653 		last_de = de;
1654 		de_buf += le16_to_cpu(de->rec_len);
1655 		offset += le16_to_cpu(de->rec_len);
1656 	}
1657 
1658 	/*
1659 	 * We're going to require expansion of the directory - figure
1660 	 * out how many blocks we'll need so that a place for the
1661 	 * dirent can be found.
1662 	 */
1663 	*blocks_wanted = 1;
1664 	new_rec_len = le16_to_cpu(last_de->rec_len) + (dir->i_sb->s_blocksize - i_size_read(dir));
1665 	if (new_rec_len < (rec_len + OCFS2_DIR_REC_LEN(last_de->name_len)))
1666 		*blocks_wanted = 2;
1667 
1668 	ret = -ENOSPC;
1669 out:
1670 	return ret;
1671 }
1672 
1673 static int ocfs2_find_dir_space_el(struct inode *dir, const char *name,
1674 				   int namelen, struct buffer_head **ret_de_bh)
1675 {
1676 	unsigned long offset;
1677 	struct buffer_head *bh = NULL;
1678 	unsigned short rec_len;
1679 	struct ocfs2_dir_entry *de;
1680 	struct super_block *sb = dir->i_sb;
1681 	int status;
1682 
1683 	bh = ocfs2_bread(dir, 0, &status, 0);
1684 	if (!bh) {
1685 		mlog_errno(status);
1686 		goto bail;
1687 	}
1688 
1689 	rec_len = OCFS2_DIR_REC_LEN(namelen);
1690 	offset = 0;
1691 	de = (struct ocfs2_dir_entry *) bh->b_data;
1692 	while (1) {
1693 		if ((char *)de >= sb->s_blocksize + bh->b_data) {
1694 			brelse(bh);
1695 			bh = NULL;
1696 
1697 			if (i_size_read(dir) <= offset) {
1698 				/*
1699 				 * Caller will have to expand this
1700 				 * directory.
1701 				 */
1702 				status = -ENOSPC;
1703 				goto bail;
1704 			}
1705 			bh = ocfs2_bread(dir,
1706 					 offset >> sb->s_blocksize_bits,
1707 					 &status,
1708 					 0);
1709 			if (!bh) {
1710 				mlog_errno(status);
1711 				goto bail;
1712 			}
1713 			/* move to next block */
1714 			de = (struct ocfs2_dir_entry *) bh->b_data;
1715 		}
1716 		if (!ocfs2_check_dir_entry(dir, de, bh, offset)) {
1717 			status = -ENOENT;
1718 			goto bail;
1719 		}
1720 		if (ocfs2_match(namelen, name, de)) {
1721 			status = -EEXIST;
1722 			goto bail;
1723 		}
1724 		if (ocfs2_dirent_would_fit(de, rec_len)) {
1725 			/* Ok, we found a spot. Return this bh and let
1726 			 * the caller actually fill it in. */
1727 			*ret_de_bh = bh;
1728 			get_bh(*ret_de_bh);
1729 			status = 0;
1730 			goto bail;
1731 		}
1732 		offset += le16_to_cpu(de->rec_len);
1733 		de = (struct ocfs2_dir_entry *)((char *) de + le16_to_cpu(de->rec_len));
1734 	}
1735 
1736 	status = 0;
1737 bail:
1738 	brelse(bh);
1739 
1740 	mlog_exit(status);
1741 	return status;
1742 }
1743 
1744 int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb,
1745 				 struct inode *dir,
1746 				 struct buffer_head *parent_fe_bh,
1747 				 const char *name,
1748 				 int namelen,
1749 				 struct buffer_head **ret_de_bh)
1750 {
1751 	int ret;
1752 	unsigned int blocks_wanted = 1;
1753 	struct buffer_head *bh = NULL;
1754 
1755 	mlog(0, "getting ready to insert namelen %d into dir %llu\n",
1756 	     namelen, (unsigned long long)OCFS2_I(dir)->ip_blkno);
1757 
1758 	*ret_de_bh = NULL;
1759 
1760 	if (!namelen) {
1761 		ret = -EINVAL;
1762 		mlog_errno(ret);
1763 		goto out;
1764 	}
1765 
1766 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1767 		ret = ocfs2_find_dir_space_id(dir, parent_fe_bh, name,
1768 					      namelen, &bh, &blocks_wanted);
1769 	} else
1770 		ret = ocfs2_find_dir_space_el(dir, name, namelen, &bh);
1771 
1772 	if (ret && ret != -ENOSPC) {
1773 		mlog_errno(ret);
1774 		goto out;
1775 	}
1776 
1777 	if (ret == -ENOSPC) {
1778 		/*
1779 		 * We have to expand the directory to add this name.
1780 		 */
1781 		BUG_ON(bh);
1782 
1783 		ret = ocfs2_extend_dir(osb, dir, parent_fe_bh, blocks_wanted,
1784 				       &bh);
1785 		if (ret) {
1786 			if (ret != -ENOSPC)
1787 				mlog_errno(ret);
1788 			goto out;
1789 		}
1790 
1791 		BUG_ON(!bh);
1792 	}
1793 
1794 	*ret_de_bh = bh;
1795 	bh = NULL;
1796 out:
1797 	brelse(bh);
1798 	return ret;
1799 }
1800