ocfs2: don't use MLF* in the file system
[linux-2.6.git] / fs / ocfs2 / dir.c
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 "uptodate.h"
59
60 #include "buffer_head_io.h"
61
62 static unsigned char ocfs2_filetype_table[] = {
63         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
64 };
65
66 static int ocfs2_extend_dir(struct ocfs2_super *osb,
67                             struct inode *dir,
68                             struct buffer_head *parent_fe_bh,
69                             struct buffer_head **new_de_bh);
70 /*
71  * ocfs2_readdir()
72  *
73  */
74 int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir)
75 {
76         int error = 0;
77         unsigned long offset, blk;
78         int i, num, stored;
79         struct buffer_head * bh, * tmp;
80         struct ocfs2_dir_entry * de;
81         int err;
82         struct inode *inode = filp->f_dentry->d_inode;
83         struct super_block * sb = inode->i_sb;
84         int have_disk_lock = 0;
85
86         mlog_entry("dirino=%llu\n",
87                    (unsigned long long)OCFS2_I(inode)->ip_blkno);
88
89         stored = 0;
90         bh = NULL;
91
92         error = ocfs2_meta_lock(inode, NULL, NULL, 0);
93         if (error < 0) {
94                 if (error != -ENOENT)
95                         mlog_errno(error);
96                 /* we haven't got any yet, so propagate the error. */
97                 stored = error;
98                 goto bail;
99         }
100         have_disk_lock = 1;
101
102         offset = filp->f_pos & (sb->s_blocksize - 1);
103
104         while (!error && !stored && filp->f_pos < i_size_read(inode)) {
105                 blk = (filp->f_pos) >> sb->s_blocksize_bits;
106                 bh = ocfs2_bread(inode, blk, &err, 0);
107                 if (!bh) {
108                         mlog(ML_ERROR,
109                              "directory #%llu contains a hole at offset %lld\n",
110                              (unsigned long long)OCFS2_I(inode)->ip_blkno,
111                              filp->f_pos);
112                         filp->f_pos += sb->s_blocksize - offset;
113                         continue;
114                 }
115
116                 /*
117                  * Do the readahead (8k)
118                  */
119                 if (!offset) {
120                         for (i = 16 >> (sb->s_blocksize_bits - 9), num = 0;
121                              i > 0; i--) {
122                                 tmp = ocfs2_bread(inode, ++blk, &err, 1);
123                                 if (tmp)
124                                         brelse(tmp);
125                         }
126                 }
127
128 revalidate:
129                 /* If the dir block has changed since the last call to
130                  * readdir(2), then we might be pointing to an invalid
131                  * dirent right now.  Scan from the start of the block
132                  * to make sure. */
133                 if (filp->f_version != inode->i_version) {
134                         for (i = 0; i < sb->s_blocksize && i < offset; ) {
135                                 de = (struct ocfs2_dir_entry *) (bh->b_data + i);
136                                 /* It's too expensive to do a full
137                                  * dirent test each time round this
138                                  * loop, but we do have to test at
139                                  * least that it is non-zero.  A
140                                  * failure will be detected in the
141                                  * dirent test below. */
142                                 if (le16_to_cpu(de->rec_len) <
143                                     OCFS2_DIR_REC_LEN(1))
144                                         break;
145                                 i += le16_to_cpu(de->rec_len);
146                         }
147                         offset = i;
148                         filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
149                                 | offset;
150                         filp->f_version = inode->i_version;
151                 }
152
153                 while (!error && filp->f_pos < i_size_read(inode)
154                        && offset < sb->s_blocksize) {
155                         de = (struct ocfs2_dir_entry *) (bh->b_data + offset);
156                         if (!ocfs2_check_dir_entry(inode, de, bh, offset)) {
157                                 /* On error, skip the f_pos to the
158                                    next block. */
159                                 filp->f_pos = (filp->f_pos |
160                                                (sb->s_blocksize - 1)) + 1;
161                                 brelse(bh);
162                                 goto bail;
163                         }
164                         offset += le16_to_cpu(de->rec_len);
165                         if (le64_to_cpu(de->inode)) {
166                                 /* We might block in the next section
167                                  * if the data destination is
168                                  * currently swapped out.  So, use a
169                                  * version stamp to detect whether or
170                                  * not the directory has been modified
171                                  * during the copy operation.
172                                  */
173                                 unsigned long version = filp->f_version;
174                                 unsigned char d_type = DT_UNKNOWN;
175
176                                 if (de->file_type < OCFS2_FT_MAX)
177                                         d_type = ocfs2_filetype_table[de->file_type];
178                                 error = filldir(dirent, de->name,
179                                                 de->name_len,
180                                                 filp->f_pos,
181                                                 ino_from_blkno(sb, le64_to_cpu(de->inode)),
182                                                 d_type);
183                                 if (error)
184                                         break;
185                                 if (version != filp->f_version)
186                                         goto revalidate;
187                                 stored ++;
188                         }
189                         filp->f_pos += le16_to_cpu(de->rec_len);
190                 }
191                 offset = 0;
192                 brelse(bh);
193         }
194
195         stored = 0;
196 bail:
197         if (have_disk_lock)
198                 ocfs2_meta_unlock(inode, 0);
199
200         mlog_exit(stored);
201
202         return stored;
203 }
204
205 /*
206  * NOTE: this should always be called with parent dir i_mutex taken.
207  */
208 int ocfs2_find_files_on_disk(const char *name,
209                              int namelen,
210                              u64 *blkno,
211                              struct inode *inode,
212                              struct buffer_head **dirent_bh,
213                              struct ocfs2_dir_entry **dirent)
214 {
215         int status = -ENOENT;
216         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
217
218         mlog_entry("(osb=%p, parent=%llu, name='%.*s', blkno=%p, inode=%p)\n",
219                    osb, (unsigned long long)OCFS2_I(inode)->ip_blkno,
220                    namelen, name, blkno, inode);
221
222         *dirent_bh = ocfs2_find_entry(name, namelen, inode, dirent);
223         if (!*dirent_bh || !*dirent) {
224                 status = -ENOENT;
225                 goto leave;
226         }
227
228         *blkno = le64_to_cpu((*dirent)->inode);
229
230         status = 0;
231 leave:
232         if (status < 0) {
233                 *dirent = NULL;
234                 if (*dirent_bh) {
235                         brelse(*dirent_bh);
236                         *dirent_bh = NULL;
237                 }
238         }
239
240         mlog_exit(status);
241         return status;
242 }
243
244 /* Check for a name within a directory.
245  *
246  * Return 0 if the name does not exist
247  * Return -EEXIST if the directory contains the name
248  *
249  * Callers should have i_mutex + a cluster lock on dir
250  */
251 int ocfs2_check_dir_for_entry(struct inode *dir,
252                               const char *name,
253                               int namelen)
254 {
255         int ret;
256         struct buffer_head *dirent_bh = NULL;
257         struct ocfs2_dir_entry *dirent = NULL;
258
259         mlog_entry("dir %llu, name '%.*s'\n",
260                    (unsigned long long)OCFS2_I(dir)->ip_blkno, namelen, name);
261
262         ret = -EEXIST;
263         dirent_bh = ocfs2_find_entry(name, namelen, dir, &dirent);
264         if (dirent_bh)
265                 goto bail;
266
267         ret = 0;
268 bail:
269         if (dirent_bh)
270                 brelse(dirent_bh);
271
272         mlog_exit(ret);
273         return ret;
274 }
275
276 /*
277  * routine to check that the specified directory is empty (for rmdir)
278  */
279 int ocfs2_empty_dir(struct inode *inode)
280 {
281         unsigned long offset;
282         struct buffer_head * bh;
283         struct ocfs2_dir_entry * de, * de1;
284         struct super_block * sb;
285         int err;
286
287         sb = inode->i_sb;
288         if ((i_size_read(inode) <
289              (OCFS2_DIR_REC_LEN(1) + OCFS2_DIR_REC_LEN(2))) ||
290             !(bh = ocfs2_bread(inode, 0, &err, 0))) {
291                 mlog(ML_ERROR, "bad directory (dir #%llu) - no data block\n",
292                      (unsigned long long)OCFS2_I(inode)->ip_blkno);
293                 return 1;
294         }
295
296         de = (struct ocfs2_dir_entry *) bh->b_data;
297         de1 = (struct ocfs2_dir_entry *)
298                         ((char *)de + le16_to_cpu(de->rec_len));
299         if ((le64_to_cpu(de->inode) != OCFS2_I(inode)->ip_blkno) ||
300                         !le64_to_cpu(de1->inode) ||
301                         strcmp(".", de->name) ||
302                         strcmp("..", de1->name)) {
303                 mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n",
304                      (unsigned long long)OCFS2_I(inode)->ip_blkno);
305                 brelse(bh);
306                 return 1;
307         }
308         offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
309         de = (struct ocfs2_dir_entry *)((char *)de1 + le16_to_cpu(de1->rec_len));
310         while (offset < i_size_read(inode) ) {
311                 if (!bh || (void *)de >= (void *)(bh->b_data + sb->s_blocksize)) {
312                         brelse(bh);
313                         bh = ocfs2_bread(inode,
314                                          offset >> sb->s_blocksize_bits, &err, 0);
315                         if (!bh) {
316                                 mlog(ML_ERROR, "dir %llu has a hole at %lu\n",
317                                      (unsigned long long)OCFS2_I(inode)->ip_blkno, offset);
318                                 offset += sb->s_blocksize;
319                                 continue;
320                         }
321                         de = (struct ocfs2_dir_entry *) bh->b_data;
322                 }
323                 if (!ocfs2_check_dir_entry(inode, de, bh, offset)) {
324                         brelse(bh);
325                         return 1;
326                 }
327                 if (le64_to_cpu(de->inode)) {
328                         brelse(bh);
329                         return 0;
330                 }
331                 offset += le16_to_cpu(de->rec_len);
332                 de = (struct ocfs2_dir_entry *)
333                         ((char *)de + le16_to_cpu(de->rec_len));
334         }
335         brelse(bh);
336         return 1;
337 }
338
339 /* returns a bh of the 1st new block in the allocation. */
340 int ocfs2_do_extend_dir(struct super_block *sb,
341                         struct ocfs2_journal_handle *handle,
342                         struct inode *dir,
343                         struct buffer_head *parent_fe_bh,
344                         struct ocfs2_alloc_context *data_ac,
345                         struct ocfs2_alloc_context *meta_ac,
346                         struct buffer_head **new_bh)
347 {
348         int status;
349         int extend;
350         u64 p_blkno;
351
352         spin_lock(&OCFS2_I(dir)->ip_lock);
353         extend = (i_size_read(dir) == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters));
354         spin_unlock(&OCFS2_I(dir)->ip_lock);
355
356         if (extend) {
357                 status = ocfs2_do_extend_allocation(OCFS2_SB(sb), dir, 1,
358                                                     parent_fe_bh, handle,
359                                                     data_ac, meta_ac, NULL);
360                 BUG_ON(status == -EAGAIN);
361                 if (status < 0) {
362                         mlog_errno(status);
363                         goto bail;
364                 }
365         }
366
367         status = ocfs2_extent_map_get_blocks(dir, (dir->i_blocks >>
368                                                    (sb->s_blocksize_bits - 9)),
369                                              1, &p_blkno, NULL);
370         if (status < 0) {
371                 mlog_errno(status);
372                 goto bail;
373         }
374
375         *new_bh = sb_getblk(sb, p_blkno);
376         if (!*new_bh) {
377                 status = -EIO;
378                 mlog_errno(status);
379                 goto bail;
380         }
381         status = 0;
382 bail:
383         mlog_exit(status);
384         return status;
385 }
386
387 /* assumes you already have a cluster lock on the directory. */
388 static int ocfs2_extend_dir(struct ocfs2_super *osb,
389                             struct inode *dir,
390                             struct buffer_head *parent_fe_bh,
391                             struct buffer_head **new_de_bh)
392 {
393         int status = 0;
394         int credits, num_free_extents;
395         loff_t dir_i_size;
396         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
397         struct ocfs2_alloc_context *data_ac = NULL;
398         struct ocfs2_alloc_context *meta_ac = NULL;
399         struct ocfs2_journal_handle *handle = NULL;
400         struct buffer_head *new_bh = NULL;
401         struct ocfs2_dir_entry * de;
402         struct super_block *sb = osb->sb;
403
404         mlog_entry_void();
405
406         dir_i_size = i_size_read(dir);
407         mlog(0, "extending dir %llu (i_size = %lld)\n",
408              (unsigned long long)OCFS2_I(dir)->ip_blkno, dir_i_size);
409
410         handle = ocfs2_alloc_handle(osb);
411         if (handle == NULL) {
412                 status = -ENOMEM;
413                 mlog_errno(status);
414                 goto bail;
415         }
416
417         /* dir->i_size is always block aligned. */
418         spin_lock(&OCFS2_I(dir)->ip_lock);
419         if (dir_i_size == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)) {
420                 spin_unlock(&OCFS2_I(dir)->ip_lock);
421                 num_free_extents = ocfs2_num_free_extents(osb, dir, fe);
422                 if (num_free_extents < 0) {
423                         status = num_free_extents;
424                         mlog_errno(status);
425                         goto bail;
426                 }
427
428                 if (!num_free_extents) {
429                         status = ocfs2_reserve_new_metadata(osb, handle,
430                                                             fe, &meta_ac);
431                         if (status < 0) {
432                                 if (status != -ENOSPC)
433                                         mlog_errno(status);
434                                 goto bail;
435                         }
436                 }
437
438                 status = ocfs2_reserve_clusters(osb, handle, 1, &data_ac);
439                 if (status < 0) {
440                         if (status != -ENOSPC)
441                                 mlog_errno(status);
442                         goto bail;
443                 }
444
445                 credits = ocfs2_calc_extend_credits(sb, fe, 1);
446         } else {
447                 spin_unlock(&OCFS2_I(dir)->ip_lock);
448                 credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS;
449         }
450
451         handle = ocfs2_start_trans(osb, handle, credits);
452         if (IS_ERR(handle)) {
453                 status = PTR_ERR(handle);
454                 handle = NULL;
455                 mlog_errno(status);
456                 goto bail;
457         }
458
459         status = ocfs2_do_extend_dir(osb->sb, handle, dir, parent_fe_bh,
460                                      data_ac, meta_ac, &new_bh);
461         if (status < 0) {
462                 mlog_errno(status);
463                 goto bail;
464         }
465
466         ocfs2_set_new_buffer_uptodate(dir, new_bh);
467
468         status = ocfs2_journal_access(handle, dir, new_bh,
469                                       OCFS2_JOURNAL_ACCESS_CREATE);
470         if (status < 0) {
471                 mlog_errno(status);
472                 goto bail;
473         }
474         memset(new_bh->b_data, 0, sb->s_blocksize);
475         de = (struct ocfs2_dir_entry *) new_bh->b_data;
476         de->inode = 0;
477         de->rec_len = cpu_to_le16(sb->s_blocksize);
478         status = ocfs2_journal_dirty(handle, new_bh);
479         if (status < 0) {
480                 mlog_errno(status);
481                 goto bail;
482         }
483
484         dir_i_size += dir->i_sb->s_blocksize;
485         i_size_write(dir, dir_i_size);
486         dir->i_blocks = ocfs2_align_bytes_to_sectors(dir_i_size);
487         status = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh);
488         if (status < 0) {
489                 mlog_errno(status);
490                 goto bail;
491         }
492
493         *new_de_bh = new_bh;
494         get_bh(*new_de_bh);
495 bail:
496         if (handle)
497                 ocfs2_commit_trans(handle);
498
499         if (data_ac)
500                 ocfs2_free_alloc_context(data_ac);
501         if (meta_ac)
502                 ocfs2_free_alloc_context(meta_ac);
503
504         if (new_bh)
505                 brelse(new_bh);
506
507         mlog_exit(status);
508         return status;
509 }
510
511 /*
512  * Search the dir for a good spot, extending it if necessary. The
513  * block containing an appropriate record is returned in ret_de_bh.
514  */
515 int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb,
516                                  struct inode *dir,
517                                  struct buffer_head *parent_fe_bh,
518                                  const char *name,
519                                  int namelen,
520                                  struct buffer_head **ret_de_bh)
521 {
522         unsigned long offset;
523         struct buffer_head * bh = NULL;
524         unsigned short rec_len;
525         struct ocfs2_dinode *fe;
526         struct ocfs2_dir_entry *de;
527         struct super_block *sb;
528         int status;
529
530         mlog_entry_void();
531
532         mlog(0, "getting ready to insert namelen %d into dir %llu\n",
533              namelen, (unsigned long long)OCFS2_I(dir)->ip_blkno);
534
535         BUG_ON(!S_ISDIR(dir->i_mode));
536         fe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
537         BUG_ON(le64_to_cpu(fe->i_size) != i_size_read(dir));
538
539         sb = dir->i_sb;
540
541         if (!namelen) {
542                 status = -EINVAL;
543                 mlog_errno(status);
544                 goto bail;
545         }
546
547         bh = ocfs2_bread(dir, 0, &status, 0);
548         if (!bh) {
549                 mlog_errno(status);
550                 goto bail;
551         }
552
553         rec_len = OCFS2_DIR_REC_LEN(namelen);
554         offset = 0;
555         de = (struct ocfs2_dir_entry *) bh->b_data;
556         while (1) {
557                 if ((char *)de >= sb->s_blocksize + bh->b_data) {
558                         brelse(bh);
559                         bh = NULL;
560
561                         if (i_size_read(dir) <= offset) {
562                                 status = ocfs2_extend_dir(osb,
563                                                           dir,
564                                                           parent_fe_bh,
565                                                           &bh);
566                                 if (status < 0) {
567                                         mlog_errno(status);
568                                         goto bail;
569                                 }
570                                 BUG_ON(!bh);
571                                 *ret_de_bh = bh;
572                                 get_bh(*ret_de_bh);
573                                 goto bail;
574                         }
575                         bh = ocfs2_bread(dir,
576                                          offset >> sb->s_blocksize_bits,
577                                          &status,
578                                          0);
579                         if (!bh) {
580                                 mlog_errno(status);
581                                 goto bail;
582                         }
583                         /* move to next block */
584                         de = (struct ocfs2_dir_entry *) bh->b_data;
585                 }
586                 if (!ocfs2_check_dir_entry(dir, de, bh, offset)) {
587                         status = -ENOENT;
588                         goto bail;
589                 }
590                 if (ocfs2_match(namelen, name, de)) {
591                         status = -EEXIST;
592                         goto bail;
593                 }
594                 if (((le64_to_cpu(de->inode) == 0) &&
595                      (le16_to_cpu(de->rec_len) >= rec_len)) ||
596                     (le16_to_cpu(de->rec_len) >=
597                      (OCFS2_DIR_REC_LEN(de->name_len) + rec_len))) {
598                         /* Ok, we found a spot. Return this bh and let
599                          * the caller actually fill it in. */
600                         *ret_de_bh = bh;
601                         get_bh(*ret_de_bh);
602                         status = 0;
603                         goto bail;
604                 }
605                 offset += le16_to_cpu(de->rec_len);
606                 de = (struct ocfs2_dir_entry *)((char *) de + le16_to_cpu(de->rec_len));
607         }
608
609         status = 0;
610 bail:
611         if (bh)
612                 brelse(bh);
613
614         mlog_exit(status);
615         return status;
616 }