nilfs2: set pointer to root object in inodes
[linux-2.6.git] / fs / nilfs2 / inode.c
1 /*
2  * inode.c - NILFS inode operations.
3  *
4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19  *
20  * Written by Ryusuke Konishi <ryusuke@osrg.net>
21  *
22  */
23
24 #include <linux/buffer_head.h>
25 #include <linux/gfp.h>
26 #include <linux/mpage.h>
27 #include <linux/writeback.h>
28 #include <linux/uio.h>
29 #include "nilfs.h"
30 #include "btnode.h"
31 #include "segment.h"
32 #include "page.h"
33 #include "mdt.h"
34 #include "cpfile.h"
35 #include "ifile.h"
36
37 struct nilfs_iget_args {
38         u64 ino;
39         __u64 cno;
40         struct nilfs_root *root;
41         int for_gc;
42 };
43
44 /**
45  * nilfs_get_block() - get a file block on the filesystem (callback function)
46  * @inode - inode struct of the target file
47  * @blkoff - file block number
48  * @bh_result - buffer head to be mapped on
49  * @create - indicate whether allocating the block or not when it has not
50  *      been allocated yet.
51  *
52  * This function does not issue actual read request of the specified data
53  * block. It is done by VFS.
54  */
55 int nilfs_get_block(struct inode *inode, sector_t blkoff,
56                     struct buffer_head *bh_result, int create)
57 {
58         struct nilfs_inode_info *ii = NILFS_I(inode);
59         __u64 blknum = 0;
60         int err = 0, ret;
61         struct inode *dat = nilfs_dat_inode(NILFS_I_NILFS(inode));
62         unsigned maxblocks = bh_result->b_size >> inode->i_blkbits;
63
64         down_read(&NILFS_MDT(dat)->mi_sem);
65         ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
66         up_read(&NILFS_MDT(dat)->mi_sem);
67         if (ret >= 0) { /* found */
68                 map_bh(bh_result, inode->i_sb, blknum);
69                 if (ret > 0)
70                         bh_result->b_size = (ret << inode->i_blkbits);
71                 goto out;
72         }
73         /* data block was not found */
74         if (ret == -ENOENT && create) {
75                 struct nilfs_transaction_info ti;
76
77                 bh_result->b_blocknr = 0;
78                 err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
79                 if (unlikely(err))
80                         goto out;
81                 err = nilfs_bmap_insert(ii->i_bmap, (unsigned long)blkoff,
82                                         (unsigned long)bh_result);
83                 if (unlikely(err != 0)) {
84                         if (err == -EEXIST) {
85                                 /*
86                                  * The get_block() function could be called
87                                  * from multiple callers for an inode.
88                                  * However, the page having this block must
89                                  * be locked in this case.
90                                  */
91                                 printk(KERN_WARNING
92                                        "nilfs_get_block: a race condition "
93                                        "while inserting a data block. "
94                                        "(inode number=%lu, file block "
95                                        "offset=%llu)\n",
96                                        inode->i_ino,
97                                        (unsigned long long)blkoff);
98                                 err = 0;
99                         } else if (err == -EINVAL) {
100                                 nilfs_error(inode->i_sb, __func__,
101                                             "broken bmap (inode=%lu)\n",
102                                             inode->i_ino);
103                                 err = -EIO;
104                         }
105                         nilfs_transaction_abort(inode->i_sb);
106                         goto out;
107                 }
108                 nilfs_mark_inode_dirty(inode);
109                 nilfs_transaction_commit(inode->i_sb); /* never fails */
110                 /* Error handling should be detailed */
111                 set_buffer_new(bh_result);
112                 map_bh(bh_result, inode->i_sb, 0); /* dbn must be changed
113                                                       to proper value */
114         } else if (ret == -ENOENT) {
115                 /* not found is not error (e.g. hole); must return without
116                    the mapped state flag. */
117                 ;
118         } else {
119                 err = ret;
120         }
121
122  out:
123         return err;
124 }
125
126 /**
127  * nilfs_readpage() - implement readpage() method of nilfs_aops {}
128  * address_space_operations.
129  * @file - file struct of the file to be read
130  * @page - the page to be read
131  */
132 static int nilfs_readpage(struct file *file, struct page *page)
133 {
134         return mpage_readpage(page, nilfs_get_block);
135 }
136
137 /**
138  * nilfs_readpages() - implement readpages() method of nilfs_aops {}
139  * address_space_operations.
140  * @file - file struct of the file to be read
141  * @mapping - address_space struct used for reading multiple pages
142  * @pages - the pages to be read
143  * @nr_pages - number of pages to be read
144  */
145 static int nilfs_readpages(struct file *file, struct address_space *mapping,
146                            struct list_head *pages, unsigned nr_pages)
147 {
148         return mpage_readpages(mapping, pages, nr_pages, nilfs_get_block);
149 }
150
151 static int nilfs_writepages(struct address_space *mapping,
152                             struct writeback_control *wbc)
153 {
154         struct inode *inode = mapping->host;
155         int err = 0;
156
157         if (wbc->sync_mode == WB_SYNC_ALL)
158                 err = nilfs_construct_dsync_segment(inode->i_sb, inode,
159                                                     wbc->range_start,
160                                                     wbc->range_end);
161         return err;
162 }
163
164 static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
165 {
166         struct inode *inode = page->mapping->host;
167         int err;
168
169         redirty_page_for_writepage(wbc, page);
170         unlock_page(page);
171
172         if (wbc->sync_mode == WB_SYNC_ALL) {
173                 err = nilfs_construct_segment(inode->i_sb);
174                 if (unlikely(err))
175                         return err;
176         } else if (wbc->for_reclaim)
177                 nilfs_flush_segment(inode->i_sb, inode->i_ino);
178
179         return 0;
180 }
181
182 static int nilfs_set_page_dirty(struct page *page)
183 {
184         int ret = __set_page_dirty_buffers(page);
185
186         if (ret) {
187                 struct inode *inode = page->mapping->host;
188                 struct nilfs_sb_info *sbi = NILFS_SB(inode->i_sb);
189                 unsigned nr_dirty = 1 << (PAGE_SHIFT - inode->i_blkbits);
190
191                 nilfs_set_file_dirty(sbi, inode, nr_dirty);
192         }
193         return ret;
194 }
195
196 static int nilfs_write_begin(struct file *file, struct address_space *mapping,
197                              loff_t pos, unsigned len, unsigned flags,
198                              struct page **pagep, void **fsdata)
199
200 {
201         struct inode *inode = mapping->host;
202         int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
203
204         if (unlikely(err))
205                 return err;
206
207         err = block_write_begin(mapping, pos, len, flags, pagep,
208                                 nilfs_get_block);
209         if (unlikely(err)) {
210                 loff_t isize = mapping->host->i_size;
211                 if (pos + len > isize)
212                         vmtruncate(mapping->host, isize);
213
214                 nilfs_transaction_abort(inode->i_sb);
215         }
216         return err;
217 }
218
219 static int nilfs_write_end(struct file *file, struct address_space *mapping,
220                            loff_t pos, unsigned len, unsigned copied,
221                            struct page *page, void *fsdata)
222 {
223         struct inode *inode = mapping->host;
224         unsigned start = pos & (PAGE_CACHE_SIZE - 1);
225         unsigned nr_dirty;
226         int err;
227
228         nr_dirty = nilfs_page_count_clean_buffers(page, start,
229                                                   start + copied);
230         copied = generic_write_end(file, mapping, pos, len, copied, page,
231                                    fsdata);
232         nilfs_set_file_dirty(NILFS_SB(inode->i_sb), inode, nr_dirty);
233         err = nilfs_transaction_commit(inode->i_sb);
234         return err ? : copied;
235 }
236
237 static ssize_t
238 nilfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
239                 loff_t offset, unsigned long nr_segs)
240 {
241         struct file *file = iocb->ki_filp;
242         struct inode *inode = file->f_mapping->host;
243         ssize_t size;
244
245         if (rw == WRITE)
246                 return 0;
247
248         /* Needs synchronization with the cleaner */
249         size = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
250                                   offset, nr_segs, nilfs_get_block, NULL);
251
252         /*
253          * In case of error extending write may have instantiated a few
254          * blocks outside i_size. Trim these off again.
255          */
256         if (unlikely((rw & WRITE) && size < 0)) {
257                 loff_t isize = i_size_read(inode);
258                 loff_t end = offset + iov_length(iov, nr_segs);
259
260                 if (end > isize)
261                         vmtruncate(inode, isize);
262         }
263
264         return size;
265 }
266
267 const struct address_space_operations nilfs_aops = {
268         .writepage              = nilfs_writepage,
269         .readpage               = nilfs_readpage,
270         .sync_page              = block_sync_page,
271         .writepages             = nilfs_writepages,
272         .set_page_dirty         = nilfs_set_page_dirty,
273         .readpages              = nilfs_readpages,
274         .write_begin            = nilfs_write_begin,
275         .write_end              = nilfs_write_end,
276         /* .releasepage         = nilfs_releasepage, */
277         .invalidatepage         = block_invalidatepage,
278         .direct_IO              = nilfs_direct_IO,
279         .is_partially_uptodate  = block_is_partially_uptodate,
280 };
281
282 struct inode *nilfs_new_inode(struct inode *dir, int mode)
283 {
284         struct super_block *sb = dir->i_sb;
285         struct nilfs_sb_info *sbi = NILFS_SB(sb);
286         struct inode *inode;
287         struct nilfs_inode_info *ii;
288         struct nilfs_root *root;
289         int err = -ENOMEM;
290         ino_t ino;
291
292         inode = new_inode(sb);
293         if (unlikely(!inode))
294                 goto failed;
295
296         mapping_set_gfp_mask(inode->i_mapping,
297                              mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
298
299         root = NILFS_I(dir)->i_root;
300         ii = NILFS_I(inode);
301         ii->i_state = 1 << NILFS_I_NEW;
302         ii->i_root = root;
303
304         err = nilfs_ifile_create_inode(sbi->s_ifile, &ino, &ii->i_bh);
305         if (unlikely(err))
306                 goto failed_ifile_create_inode;
307         /* reference count of i_bh inherits from nilfs_mdt_read_block() */
308
309         atomic_inc(&sbi->s_inodes_count);
310         inode_init_owner(inode, dir, mode);
311         inode->i_ino = ino;
312         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
313
314         if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
315                 err = nilfs_bmap_read(ii->i_bmap, NULL);
316                 if (err < 0)
317                         goto failed_bmap;
318
319                 set_bit(NILFS_I_BMAP, &ii->i_state);
320                 /* No lock is needed; iget() ensures it. */
321         }
322
323         ii->i_flags = NILFS_I(dir)->i_flags;
324         if (S_ISLNK(mode))
325                 ii->i_flags &= ~(NILFS_IMMUTABLE_FL | NILFS_APPEND_FL);
326         if (!S_ISDIR(mode))
327                 ii->i_flags &= ~NILFS_DIRSYNC_FL;
328
329         /* ii->i_file_acl = 0; */
330         /* ii->i_dir_acl = 0; */
331         ii->i_dir_start_lookup = 0;
332         nilfs_set_inode_flags(inode);
333         spin_lock(&sbi->s_next_gen_lock);
334         inode->i_generation = sbi->s_next_generation++;
335         spin_unlock(&sbi->s_next_gen_lock);
336         insert_inode_hash(inode);
337
338         err = nilfs_init_acl(inode, dir);
339         if (unlikely(err))
340                 goto failed_acl; /* never occur. When supporting
341                                     nilfs_init_acl(), proper cancellation of
342                                     above jobs should be considered */
343
344         return inode;
345
346  failed_acl:
347  failed_bmap:
348         inode->i_nlink = 0;
349         iput(inode);  /* raw_inode will be deleted through
350                          generic_delete_inode() */
351         goto failed;
352
353  failed_ifile_create_inode:
354         make_bad_inode(inode);
355         iput(inode);  /* if i_nlink == 1, generic_forget_inode() will be
356                          called */
357  failed:
358         return ERR_PTR(err);
359 }
360
361 void nilfs_free_inode(struct inode *inode)
362 {
363         struct super_block *sb = inode->i_sb;
364         struct nilfs_sb_info *sbi = NILFS_SB(sb);
365
366         /* XXX: check error code? Is there any thing I can do? */
367         (void) nilfs_ifile_delete_inode(sbi->s_ifile, inode->i_ino);
368         atomic_dec(&sbi->s_inodes_count);
369 }
370
371 void nilfs_set_inode_flags(struct inode *inode)
372 {
373         unsigned int flags = NILFS_I(inode)->i_flags;
374
375         inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |
376                             S_DIRSYNC);
377         if (flags & NILFS_SYNC_FL)
378                 inode->i_flags |= S_SYNC;
379         if (flags & NILFS_APPEND_FL)
380                 inode->i_flags |= S_APPEND;
381         if (flags & NILFS_IMMUTABLE_FL)
382                 inode->i_flags |= S_IMMUTABLE;
383 #ifndef NILFS_ATIME_DISABLE
384         if (flags & NILFS_NOATIME_FL)
385 #endif
386                 inode->i_flags |= S_NOATIME;
387         if (flags & NILFS_DIRSYNC_FL)
388                 inode->i_flags |= S_DIRSYNC;
389         mapping_set_gfp_mask(inode->i_mapping,
390                              mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
391 }
392
393 int nilfs_read_inode_common(struct inode *inode,
394                             struct nilfs_inode *raw_inode)
395 {
396         struct nilfs_inode_info *ii = NILFS_I(inode);
397         int err;
398
399         inode->i_mode = le16_to_cpu(raw_inode->i_mode);
400         inode->i_uid = (uid_t)le32_to_cpu(raw_inode->i_uid);
401         inode->i_gid = (gid_t)le32_to_cpu(raw_inode->i_gid);
402         inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
403         inode->i_size = le64_to_cpu(raw_inode->i_size);
404         inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
405         inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
406         inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
407         inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
408         inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
409         inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
410         if (inode->i_nlink == 0 && inode->i_mode == 0)
411                 return -EINVAL; /* this inode is deleted */
412
413         inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
414         ii->i_flags = le32_to_cpu(raw_inode->i_flags);
415 #if 0
416         ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
417         ii->i_dir_acl = S_ISREG(inode->i_mode) ?
418                 0 : le32_to_cpu(raw_inode->i_dir_acl);
419 #endif
420         ii->i_dir_start_lookup = 0;
421         inode->i_generation = le32_to_cpu(raw_inode->i_generation);
422
423         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
424             S_ISLNK(inode->i_mode)) {
425                 err = nilfs_bmap_read(ii->i_bmap, raw_inode);
426                 if (err < 0)
427                         return err;
428                 set_bit(NILFS_I_BMAP, &ii->i_state);
429                 /* No lock is needed; iget() ensures it. */
430         }
431         return 0;
432 }
433
434 static int __nilfs_read_inode(struct super_block *sb, unsigned long ino,
435                               struct inode *inode)
436 {
437         struct nilfs_sb_info *sbi = NILFS_SB(sb);
438         struct inode *dat = nilfs_dat_inode(sbi->s_nilfs);
439         struct buffer_head *bh;
440         struct nilfs_inode *raw_inode;
441         int err;
442
443         down_read(&NILFS_MDT(dat)->mi_sem);     /* XXX */
444         err = nilfs_ifile_get_inode_block(sbi->s_ifile, ino, &bh);
445         if (unlikely(err))
446                 goto bad_inode;
447
448         raw_inode = nilfs_ifile_map_inode(sbi->s_ifile, ino, bh);
449
450         err = nilfs_read_inode_common(inode, raw_inode);
451         if (err)
452                 goto failed_unmap;
453
454         if (S_ISREG(inode->i_mode)) {
455                 inode->i_op = &nilfs_file_inode_operations;
456                 inode->i_fop = &nilfs_file_operations;
457                 inode->i_mapping->a_ops = &nilfs_aops;
458         } else if (S_ISDIR(inode->i_mode)) {
459                 inode->i_op = &nilfs_dir_inode_operations;
460                 inode->i_fop = &nilfs_dir_operations;
461                 inode->i_mapping->a_ops = &nilfs_aops;
462         } else if (S_ISLNK(inode->i_mode)) {
463                 inode->i_op = &nilfs_symlink_inode_operations;
464                 inode->i_mapping->a_ops = &nilfs_aops;
465         } else {
466                 inode->i_op = &nilfs_special_inode_operations;
467                 init_special_inode(
468                         inode, inode->i_mode,
469                         huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
470         }
471         nilfs_ifile_unmap_inode(sbi->s_ifile, ino, bh);
472         brelse(bh);
473         up_read(&NILFS_MDT(dat)->mi_sem);       /* XXX */
474         nilfs_set_inode_flags(inode);
475         return 0;
476
477  failed_unmap:
478         nilfs_ifile_unmap_inode(sbi->s_ifile, ino, bh);
479         brelse(bh);
480
481  bad_inode:
482         up_read(&NILFS_MDT(dat)->mi_sem);       /* XXX */
483         return err;
484 }
485
486 static int nilfs_iget_test(struct inode *inode, void *opaque)
487 {
488         struct nilfs_iget_args *args = opaque;
489         struct nilfs_inode_info *ii;
490
491         if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
492                 return 0;
493
494         ii = NILFS_I(inode);
495         if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
496                 return !args->for_gc;
497
498         return args->for_gc && args->cno == ii->i_cno;
499 }
500
501 static int nilfs_iget_set(struct inode *inode, void *opaque)
502 {
503         struct nilfs_iget_args *args = opaque;
504
505         inode->i_ino = args->ino;
506         if (args->for_gc) {
507                 NILFS_I(inode)->i_state = 1 << NILFS_I_GCINODE;
508                 NILFS_I(inode)->i_cno = args->cno;
509                 NILFS_I(inode)->i_root = NULL;
510         } else {
511                 if (args->root && args->ino == NILFS_ROOT_INO)
512                         nilfs_get_root(args->root);
513                 NILFS_I(inode)->i_root = args->root;
514         }
515         return 0;
516 }
517
518 struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
519                          unsigned long ino)
520 {
521         struct nilfs_iget_args args = {
522                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
523         };
524         struct inode *inode;
525         int err;
526
527         inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
528         if (unlikely(!inode))
529                 return ERR_PTR(-ENOMEM);
530         if (!(inode->i_state & I_NEW))
531                 return inode;
532
533         err = __nilfs_read_inode(sb, ino, inode);
534         if (unlikely(err)) {
535                 iget_failed(inode);
536                 return ERR_PTR(err);
537         }
538         unlock_new_inode(inode);
539         return inode;
540 }
541
542 struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
543                                 __u64 cno)
544 {
545         struct nilfs_iget_args args = {
546                 .ino = ino, .root = NULL, .cno = cno, .for_gc = 1
547         };
548         struct inode *inode;
549         int err;
550
551         inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
552         if (unlikely(!inode))
553                 return ERR_PTR(-ENOMEM);
554         if (!(inode->i_state & I_NEW))
555                 return inode;
556
557         err = nilfs_init_gcinode(inode);
558         if (unlikely(err)) {
559                 iget_failed(inode);
560                 return ERR_PTR(err);
561         }
562         unlock_new_inode(inode);
563         return inode;
564 }
565
566 void nilfs_write_inode_common(struct inode *inode,
567                               struct nilfs_inode *raw_inode, int has_bmap)
568 {
569         struct nilfs_inode_info *ii = NILFS_I(inode);
570
571         raw_inode->i_mode = cpu_to_le16(inode->i_mode);
572         raw_inode->i_uid = cpu_to_le32(inode->i_uid);
573         raw_inode->i_gid = cpu_to_le32(inode->i_gid);
574         raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
575         raw_inode->i_size = cpu_to_le64(inode->i_size);
576         raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
577         raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
578         raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
579         raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
580         raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
581
582         raw_inode->i_flags = cpu_to_le32(ii->i_flags);
583         raw_inode->i_generation = cpu_to_le32(inode->i_generation);
584
585         if (has_bmap)
586                 nilfs_bmap_write(ii->i_bmap, raw_inode);
587         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
588                 raw_inode->i_device_code =
589                         cpu_to_le64(huge_encode_dev(inode->i_rdev));
590         /* When extending inode, nilfs->ns_inode_size should be checked
591            for substitutions of appended fields */
592 }
593
594 void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh)
595 {
596         ino_t ino = inode->i_ino;
597         struct nilfs_inode_info *ii = NILFS_I(inode);
598         struct super_block *sb = inode->i_sb;
599         struct nilfs_sb_info *sbi = NILFS_SB(sb);
600         struct nilfs_inode *raw_inode;
601
602         raw_inode = nilfs_ifile_map_inode(sbi->s_ifile, ino, ibh);
603
604         if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
605                 memset(raw_inode, 0, NILFS_MDT(sbi->s_ifile)->mi_entry_size);
606         set_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
607
608         nilfs_write_inode_common(inode, raw_inode, 0);
609                 /* XXX: call with has_bmap = 0 is a workaround to avoid
610                    deadlock of bmap. This delays update of i_bmap to just
611                    before writing */
612         nilfs_ifile_unmap_inode(sbi->s_ifile, ino, ibh);
613 }
614
615 #define NILFS_MAX_TRUNCATE_BLOCKS       16384  /* 64MB for 4KB block */
616
617 static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
618                                 unsigned long from)
619 {
620         unsigned long b;
621         int ret;
622
623         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
624                 return;
625  repeat:
626         ret = nilfs_bmap_last_key(ii->i_bmap, &b);
627         if (ret == -ENOENT)
628                 return;
629         else if (ret < 0)
630                 goto failed;
631
632         if (b < from)
633                 return;
634
635         b -= min_t(unsigned long, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
636         ret = nilfs_bmap_truncate(ii->i_bmap, b);
637         nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
638         if (!ret || (ret == -ENOMEM &&
639                      nilfs_bmap_truncate(ii->i_bmap, b) == 0))
640                 goto repeat;
641
642  failed:
643         if (ret == -EINVAL)
644                 nilfs_error(ii->vfs_inode.i_sb, __func__,
645                             "bmap is broken (ino=%lu)", ii->vfs_inode.i_ino);
646         else
647                 nilfs_warning(ii->vfs_inode.i_sb, __func__,
648                               "failed to truncate bmap (ino=%lu, err=%d)",
649                               ii->vfs_inode.i_ino, ret);
650 }
651
652 void nilfs_truncate(struct inode *inode)
653 {
654         unsigned long blkoff;
655         unsigned int blocksize;
656         struct nilfs_transaction_info ti;
657         struct super_block *sb = inode->i_sb;
658         struct nilfs_inode_info *ii = NILFS_I(inode);
659
660         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
661                 return;
662         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
663                 return;
664
665         blocksize = sb->s_blocksize;
666         blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
667         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
668
669         block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
670
671         nilfs_truncate_bmap(ii, blkoff);
672
673         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
674         if (IS_SYNC(inode))
675                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
676
677         nilfs_mark_inode_dirty(inode);
678         nilfs_set_file_dirty(NILFS_SB(sb), inode, 0);
679         nilfs_transaction_commit(sb);
680         /* May construct a logical segment and may fail in sync mode.
681            But truncate has no return value. */
682 }
683
684 static void nilfs_clear_inode(struct inode *inode)
685 {
686         struct nilfs_inode_info *ii = NILFS_I(inode);
687
688         /*
689          * Free resources allocated in nilfs_read_inode(), here.
690          */
691         BUG_ON(!list_empty(&ii->i_dirty));
692         brelse(ii->i_bh);
693         ii->i_bh = NULL;
694
695         if (test_bit(NILFS_I_BMAP, &ii->i_state))
696                 nilfs_bmap_clear(ii->i_bmap);
697
698         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
699
700         if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
701                 nilfs_put_root(ii->i_root);
702 }
703
704 void nilfs_evict_inode(struct inode *inode)
705 {
706         struct nilfs_transaction_info ti;
707         struct super_block *sb = inode->i_sb;
708         struct nilfs_inode_info *ii = NILFS_I(inode);
709
710         if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
711                 if (inode->i_data.nrpages)
712                         truncate_inode_pages(&inode->i_data, 0);
713                 end_writeback(inode);
714                 nilfs_clear_inode(inode);
715                 return;
716         }
717         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
718
719         if (inode->i_data.nrpages)
720                 truncate_inode_pages(&inode->i_data, 0);
721
722         nilfs_truncate_bmap(ii, 0);
723         nilfs_mark_inode_dirty(inode);
724         end_writeback(inode);
725         nilfs_clear_inode(inode);
726         nilfs_free_inode(inode);
727         /* nilfs_free_inode() marks inode buffer dirty */
728         if (IS_SYNC(inode))
729                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
730         nilfs_transaction_commit(sb);
731         /* May construct a logical segment and may fail in sync mode.
732            But delete_inode has no return value. */
733 }
734
735 int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
736 {
737         struct nilfs_transaction_info ti;
738         struct inode *inode = dentry->d_inode;
739         struct super_block *sb = inode->i_sb;
740         int err;
741
742         err = inode_change_ok(inode, iattr);
743         if (err)
744                 return err;
745
746         err = nilfs_transaction_begin(sb, &ti, 0);
747         if (unlikely(err))
748                 return err;
749
750         if ((iattr->ia_valid & ATTR_SIZE) &&
751             iattr->ia_size != i_size_read(inode)) {
752                 err = vmtruncate(inode, iattr->ia_size);
753                 if (unlikely(err))
754                         goto out_err;
755         }
756
757         setattr_copy(inode, iattr);
758         mark_inode_dirty(inode);
759
760         if (iattr->ia_valid & ATTR_MODE) {
761                 err = nilfs_acl_chmod(inode);
762                 if (unlikely(err))
763                         goto out_err;
764         }
765
766         return nilfs_transaction_commit(sb);
767
768 out_err:
769         nilfs_transaction_abort(sb);
770         return err;
771 }
772
773 int nilfs_load_inode_block(struct nilfs_sb_info *sbi, struct inode *inode,
774                            struct buffer_head **pbh)
775 {
776         struct nilfs_inode_info *ii = NILFS_I(inode);
777         int err;
778
779         spin_lock(&sbi->s_inode_lock);
780         if (ii->i_bh == NULL) {
781                 spin_unlock(&sbi->s_inode_lock);
782                 err = nilfs_ifile_get_inode_block(sbi->s_ifile, inode->i_ino,
783                                                   pbh);
784                 if (unlikely(err))
785                         return err;
786                 spin_lock(&sbi->s_inode_lock);
787                 if (ii->i_bh == NULL)
788                         ii->i_bh = *pbh;
789                 else {
790                         brelse(*pbh);
791                         *pbh = ii->i_bh;
792                 }
793         } else
794                 *pbh = ii->i_bh;
795
796         get_bh(*pbh);
797         spin_unlock(&sbi->s_inode_lock);
798         return 0;
799 }
800
801 int nilfs_inode_dirty(struct inode *inode)
802 {
803         struct nilfs_inode_info *ii = NILFS_I(inode);
804         struct nilfs_sb_info *sbi = NILFS_SB(inode->i_sb);
805         int ret = 0;
806
807         if (!list_empty(&ii->i_dirty)) {
808                 spin_lock(&sbi->s_inode_lock);
809                 ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
810                         test_bit(NILFS_I_BUSY, &ii->i_state);
811                 spin_unlock(&sbi->s_inode_lock);
812         }
813         return ret;
814 }
815
816 int nilfs_set_file_dirty(struct nilfs_sb_info *sbi, struct inode *inode,
817                          unsigned nr_dirty)
818 {
819         struct nilfs_inode_info *ii = NILFS_I(inode);
820
821         atomic_add(nr_dirty, &sbi->s_nilfs->ns_ndirtyblks);
822
823         if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
824                 return 0;
825
826         spin_lock(&sbi->s_inode_lock);
827         if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
828             !test_bit(NILFS_I_BUSY, &ii->i_state)) {
829                 /* Because this routine may race with nilfs_dispose_list(),
830                    we have to check NILFS_I_QUEUED here, too. */
831                 if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
832                         /* This will happen when somebody is freeing
833                            this inode. */
834                         nilfs_warning(sbi->s_super, __func__,
835                                       "cannot get inode (ino=%lu)\n",
836                                       inode->i_ino);
837                         spin_unlock(&sbi->s_inode_lock);
838                         return -EINVAL; /* NILFS_I_DIRTY may remain for
839                                            freeing inode */
840                 }
841                 list_del(&ii->i_dirty);
842                 list_add_tail(&ii->i_dirty, &sbi->s_dirty_files);
843                 set_bit(NILFS_I_QUEUED, &ii->i_state);
844         }
845         spin_unlock(&sbi->s_inode_lock);
846         return 0;
847 }
848
849 int nilfs_mark_inode_dirty(struct inode *inode)
850 {
851         struct nilfs_sb_info *sbi = NILFS_SB(inode->i_sb);
852         struct buffer_head *ibh;
853         int err;
854
855         err = nilfs_load_inode_block(sbi, inode, &ibh);
856         if (unlikely(err)) {
857                 nilfs_warning(inode->i_sb, __func__,
858                               "failed to reget inode block.\n");
859                 return err;
860         }
861         nilfs_update_inode(inode, ibh);
862         nilfs_mdt_mark_buffer_dirty(ibh);
863         nilfs_mdt_mark_dirty(sbi->s_ifile);
864         brelse(ibh);
865         return 0;
866 }
867
868 /**
869  * nilfs_dirty_inode - reflect changes on given inode to an inode block.
870  * @inode: inode of the file to be registered.
871  *
872  * nilfs_dirty_inode() loads a inode block containing the specified
873  * @inode and copies data from a nilfs_inode to a corresponding inode
874  * entry in the inode block. This operation is excluded from the segment
875  * construction. This function can be called both as a single operation
876  * and as a part of indivisible file operations.
877  */
878 void nilfs_dirty_inode(struct inode *inode)
879 {
880         struct nilfs_transaction_info ti;
881         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
882
883         if (is_bad_inode(inode)) {
884                 nilfs_warning(inode->i_sb, __func__,
885                               "tried to mark bad_inode dirty. ignored.\n");
886                 dump_stack();
887                 return;
888         }
889         if (mdi) {
890                 nilfs_mdt_mark_dirty(inode);
891                 return;
892         }
893         nilfs_transaction_begin(inode->i_sb, &ti, 0);
894         nilfs_mark_inode_dirty(inode);
895         nilfs_transaction_commit(inode->i_sb); /* never fails */
896 }