GNU Linux-libre 4.9.308-gnu1
[releases.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  * Written by Ryusuke Konishi.
17  *
18  */
19
20 #include <linux/buffer_head.h>
21 #include <linux/gfp.h>
22 #include <linux/mpage.h>
23 #include <linux/pagemap.h>
24 #include <linux/writeback.h>
25 #include <linux/uio.h>
26 #include "nilfs.h"
27 #include "btnode.h"
28 #include "segment.h"
29 #include "page.h"
30 #include "mdt.h"
31 #include "cpfile.h"
32 #include "ifile.h"
33
34 /**
35  * struct nilfs_iget_args - arguments used during comparison between inodes
36  * @ino: inode number
37  * @cno: checkpoint number
38  * @root: pointer on NILFS root object (mounted checkpoint)
39  * @for_gc: inode for GC flag
40  */
41 struct nilfs_iget_args {
42         u64 ino;
43         __u64 cno;
44         struct nilfs_root *root;
45         int for_gc;
46 };
47
48 static int nilfs_iget_test(struct inode *inode, void *opaque);
49
50 void nilfs_inode_add_blocks(struct inode *inode, int n)
51 {
52         struct nilfs_root *root = NILFS_I(inode)->i_root;
53
54         inode_add_bytes(inode, i_blocksize(inode) * n);
55         if (root)
56                 atomic64_add(n, &root->blocks_count);
57 }
58
59 void nilfs_inode_sub_blocks(struct inode *inode, int n)
60 {
61         struct nilfs_root *root = NILFS_I(inode)->i_root;
62
63         inode_sub_bytes(inode, i_blocksize(inode) * n);
64         if (root)
65                 atomic64_sub(n, &root->blocks_count);
66 }
67
68 /**
69  * nilfs_get_block() - get a file block on the filesystem (callback function)
70  * @inode - inode struct of the target file
71  * @blkoff - file block number
72  * @bh_result - buffer head to be mapped on
73  * @create - indicate whether allocating the block or not when it has not
74  *      been allocated yet.
75  *
76  * This function does not issue actual read request of the specified data
77  * block. It is done by VFS.
78  */
79 int nilfs_get_block(struct inode *inode, sector_t blkoff,
80                     struct buffer_head *bh_result, int create)
81 {
82         struct nilfs_inode_info *ii = NILFS_I(inode);
83         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
84         __u64 blknum = 0;
85         int err = 0, ret;
86         unsigned int maxblocks = bh_result->b_size >> inode->i_blkbits;
87
88         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
89         ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
90         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
91         if (ret >= 0) { /* found */
92                 map_bh(bh_result, inode->i_sb, blknum);
93                 if (ret > 0)
94                         bh_result->b_size = (ret << inode->i_blkbits);
95                 goto out;
96         }
97         /* data block was not found */
98         if (ret == -ENOENT && create) {
99                 struct nilfs_transaction_info ti;
100
101                 bh_result->b_blocknr = 0;
102                 err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
103                 if (unlikely(err))
104                         goto out;
105                 err = nilfs_bmap_insert(ii->i_bmap, blkoff,
106                                         (unsigned long)bh_result);
107                 if (unlikely(err != 0)) {
108                         if (err == -EEXIST) {
109                                 /*
110                                  * The get_block() function could be called
111                                  * from multiple callers for an inode.
112                                  * However, the page having this block must
113                                  * be locked in this case.
114                                  */
115                                 nilfs_msg(inode->i_sb, KERN_WARNING,
116                                           "%s (ino=%lu): a race condition while inserting a data block at offset=%llu",
117                                           __func__, inode->i_ino,
118                                           (unsigned long long)blkoff);
119                                 err = 0;
120                         }
121                         nilfs_transaction_abort(inode->i_sb);
122                         goto out;
123                 }
124                 nilfs_mark_inode_dirty_sync(inode);
125                 nilfs_transaction_commit(inode->i_sb); /* never fails */
126                 /* Error handling should be detailed */
127                 set_buffer_new(bh_result);
128                 set_buffer_delay(bh_result);
129                 map_bh(bh_result, inode->i_sb, 0);
130                 /* Disk block number must be changed to proper value */
131
132         } else if (ret == -ENOENT) {
133                 /*
134                  * not found is not error (e.g. hole); must return without
135                  * the mapped state flag.
136                  */
137                 ;
138         } else {
139                 err = ret;
140         }
141
142  out:
143         return err;
144 }
145
146 /**
147  * nilfs_readpage() - implement readpage() method of nilfs_aops {}
148  * address_space_operations.
149  * @file - file struct of the file to be read
150  * @page - the page to be read
151  */
152 static int nilfs_readpage(struct file *file, struct page *page)
153 {
154         return mpage_readpage(page, nilfs_get_block);
155 }
156
157 /**
158  * nilfs_readpages() - implement readpages() method of nilfs_aops {}
159  * address_space_operations.
160  * @file - file struct of the file to be read
161  * @mapping - address_space struct used for reading multiple pages
162  * @pages - the pages to be read
163  * @nr_pages - number of pages to be read
164  */
165 static int nilfs_readpages(struct file *file, struct address_space *mapping,
166                            struct list_head *pages, unsigned int nr_pages)
167 {
168         return mpage_readpages(mapping, pages, nr_pages, nilfs_get_block);
169 }
170
171 static int nilfs_writepages(struct address_space *mapping,
172                             struct writeback_control *wbc)
173 {
174         struct inode *inode = mapping->host;
175         int err = 0;
176
177         if (inode->i_sb->s_flags & MS_RDONLY) {
178                 nilfs_clear_dirty_pages(mapping, false);
179                 return -EROFS;
180         }
181
182         if (wbc->sync_mode == WB_SYNC_ALL)
183                 err = nilfs_construct_dsync_segment(inode->i_sb, inode,
184                                                     wbc->range_start,
185                                                     wbc->range_end);
186         return err;
187 }
188
189 static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
190 {
191         struct inode *inode = page->mapping->host;
192         int err;
193
194         if (inode->i_sb->s_flags & MS_RDONLY) {
195                 /*
196                  * It means that filesystem was remounted in read-only
197                  * mode because of error or metadata corruption. But we
198                  * have dirty pages that try to be flushed in background.
199                  * So, here we simply discard this dirty page.
200                  */
201                 nilfs_clear_dirty_page(page, false);
202                 unlock_page(page);
203                 return -EROFS;
204         }
205
206         redirty_page_for_writepage(wbc, page);
207         unlock_page(page);
208
209         if (wbc->sync_mode == WB_SYNC_ALL) {
210                 err = nilfs_construct_segment(inode->i_sb);
211                 if (unlikely(err))
212                         return err;
213         } else if (wbc->for_reclaim)
214                 nilfs_flush_segment(inode->i_sb, inode->i_ino);
215
216         return 0;
217 }
218
219 static int nilfs_set_page_dirty(struct page *page)
220 {
221         struct inode *inode = page->mapping->host;
222         int ret = __set_page_dirty_nobuffers(page);
223
224         if (page_has_buffers(page)) {
225                 unsigned int nr_dirty = 0;
226                 struct buffer_head *bh, *head;
227
228                 /*
229                  * This page is locked by callers, and no other thread
230                  * concurrently marks its buffers dirty since they are
231                  * only dirtied through routines in fs/buffer.c in
232                  * which call sites of mark_buffer_dirty are protected
233                  * by page lock.
234                  */
235                 bh = head = page_buffers(page);
236                 do {
237                         /* Do not mark hole blocks dirty */
238                         if (buffer_dirty(bh) || !buffer_mapped(bh))
239                                 continue;
240
241                         set_buffer_dirty(bh);
242                         nr_dirty++;
243                 } while (bh = bh->b_this_page, bh != head);
244
245                 if (nr_dirty)
246                         nilfs_set_file_dirty(inode, nr_dirty);
247         } else if (ret) {
248                 unsigned int nr_dirty = 1 << (PAGE_SHIFT - inode->i_blkbits);
249
250                 nilfs_set_file_dirty(inode, nr_dirty);
251         }
252         return ret;
253 }
254
255 void nilfs_write_failed(struct address_space *mapping, loff_t to)
256 {
257         struct inode *inode = mapping->host;
258
259         if (to > inode->i_size) {
260                 truncate_pagecache(inode, inode->i_size);
261                 nilfs_truncate(inode);
262         }
263 }
264
265 static int nilfs_write_begin(struct file *file, struct address_space *mapping,
266                              loff_t pos, unsigned len, unsigned flags,
267                              struct page **pagep, void **fsdata)
268
269 {
270         struct inode *inode = mapping->host;
271         int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
272
273         if (unlikely(err))
274                 return err;
275
276         err = block_write_begin(mapping, pos, len, flags, pagep,
277                                 nilfs_get_block);
278         if (unlikely(err)) {
279                 nilfs_write_failed(mapping, pos + len);
280                 nilfs_transaction_abort(inode->i_sb);
281         }
282         return err;
283 }
284
285 static int nilfs_write_end(struct file *file, struct address_space *mapping,
286                            loff_t pos, unsigned len, unsigned copied,
287                            struct page *page, void *fsdata)
288 {
289         struct inode *inode = mapping->host;
290         unsigned int start = pos & (PAGE_SIZE - 1);
291         unsigned int nr_dirty;
292         int err;
293
294         nr_dirty = nilfs_page_count_clean_buffers(page, start,
295                                                   start + copied);
296         copied = generic_write_end(file, mapping, pos, len, copied, page,
297                                    fsdata);
298         nilfs_set_file_dirty(inode, nr_dirty);
299         err = nilfs_transaction_commit(inode->i_sb);
300         return err ? : copied;
301 }
302
303 static ssize_t
304 nilfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
305 {
306         struct inode *inode = file_inode(iocb->ki_filp);
307
308         if (iov_iter_rw(iter) == WRITE)
309                 return 0;
310
311         /* Needs synchronization with the cleaner */
312         return blockdev_direct_IO(iocb, inode, iter, nilfs_get_block);
313 }
314
315 const struct address_space_operations nilfs_aops = {
316         .writepage              = nilfs_writepage,
317         .readpage               = nilfs_readpage,
318         .writepages             = nilfs_writepages,
319         .set_page_dirty         = nilfs_set_page_dirty,
320         .readpages              = nilfs_readpages,
321         .write_begin            = nilfs_write_begin,
322         .write_end              = nilfs_write_end,
323         /* .releasepage         = nilfs_releasepage, */
324         .invalidatepage         = block_invalidatepage,
325         .direct_IO              = nilfs_direct_IO,
326         .is_partially_uptodate  = block_is_partially_uptodate,
327 };
328
329 static int nilfs_insert_inode_locked(struct inode *inode,
330                                      struct nilfs_root *root,
331                                      unsigned long ino)
332 {
333         struct nilfs_iget_args args = {
334                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
335         };
336
337         return insert_inode_locked4(inode, ino, nilfs_iget_test, &args);
338 }
339
340 struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
341 {
342         struct super_block *sb = dir->i_sb;
343         struct the_nilfs *nilfs = sb->s_fs_info;
344         struct inode *inode;
345         struct nilfs_inode_info *ii;
346         struct nilfs_root *root;
347         int err = -ENOMEM;
348         ino_t ino;
349
350         inode = new_inode(sb);
351         if (unlikely(!inode))
352                 goto failed;
353
354         mapping_set_gfp_mask(inode->i_mapping,
355                            mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
356
357         root = NILFS_I(dir)->i_root;
358         ii = NILFS_I(inode);
359         ii->i_state = BIT(NILFS_I_NEW);
360         ii->i_root = root;
361
362         err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
363         if (unlikely(err))
364                 goto failed_ifile_create_inode;
365         /* reference count of i_bh inherits from nilfs_mdt_read_block() */
366
367         atomic64_inc(&root->inodes_count);
368         inode_init_owner(inode, dir, mode);
369         inode->i_ino = ino;
370         inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
371
372         if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
373                 err = nilfs_bmap_read(ii->i_bmap, NULL);
374                 if (err < 0)
375                         goto failed_after_creation;
376
377                 set_bit(NILFS_I_BMAP, &ii->i_state);
378                 /* No lock is needed; iget() ensures it. */
379         }
380
381         ii->i_flags = nilfs_mask_flags(
382                 mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
383
384         /* ii->i_file_acl = 0; */
385         /* ii->i_dir_acl = 0; */
386         ii->i_dir_start_lookup = 0;
387         nilfs_set_inode_flags(inode);
388         spin_lock(&nilfs->ns_next_gen_lock);
389         inode->i_generation = nilfs->ns_next_generation++;
390         spin_unlock(&nilfs->ns_next_gen_lock);
391         if (nilfs_insert_inode_locked(inode, root, ino) < 0) {
392                 err = -EIO;
393                 goto failed_after_creation;
394         }
395
396         err = nilfs_init_acl(inode, dir);
397         if (unlikely(err))
398                 /*
399                  * Never occur.  When supporting nilfs_init_acl(),
400                  * proper cancellation of above jobs should be considered.
401                  */
402                 goto failed_after_creation;
403
404         return inode;
405
406  failed_after_creation:
407         clear_nlink(inode);
408         unlock_new_inode(inode);
409         iput(inode);  /*
410                        * raw_inode will be deleted through
411                        * nilfs_evict_inode().
412                        */
413         goto failed;
414
415  failed_ifile_create_inode:
416         make_bad_inode(inode);
417         iput(inode);
418  failed:
419         return ERR_PTR(err);
420 }
421
422 void nilfs_set_inode_flags(struct inode *inode)
423 {
424         unsigned int flags = NILFS_I(inode)->i_flags;
425         unsigned int new_fl = 0;
426
427         if (flags & FS_SYNC_FL)
428                 new_fl |= S_SYNC;
429         if (flags & FS_APPEND_FL)
430                 new_fl |= S_APPEND;
431         if (flags & FS_IMMUTABLE_FL)
432                 new_fl |= S_IMMUTABLE;
433         if (flags & FS_NOATIME_FL)
434                 new_fl |= S_NOATIME;
435         if (flags & FS_DIRSYNC_FL)
436                 new_fl |= S_DIRSYNC;
437         inode_set_flags(inode, new_fl, S_SYNC | S_APPEND | S_IMMUTABLE |
438                         S_NOATIME | S_DIRSYNC);
439 }
440
441 int nilfs_read_inode_common(struct inode *inode,
442                             struct nilfs_inode *raw_inode)
443 {
444         struct nilfs_inode_info *ii = NILFS_I(inode);
445         int err;
446
447         inode->i_mode = le16_to_cpu(raw_inode->i_mode);
448         i_uid_write(inode, le32_to_cpu(raw_inode->i_uid));
449         i_gid_write(inode, le32_to_cpu(raw_inode->i_gid));
450         set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
451         inode->i_size = le64_to_cpu(raw_inode->i_size);
452         inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
453         inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
454         inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
455         inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
456         inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
457         inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
458         if (inode->i_nlink == 0)
459                 return -ESTALE; /* this inode is deleted */
460
461         inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
462         ii->i_flags = le32_to_cpu(raw_inode->i_flags);
463 #if 0
464         ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
465         ii->i_dir_acl = S_ISREG(inode->i_mode) ?
466                 0 : le32_to_cpu(raw_inode->i_dir_acl);
467 #endif
468         ii->i_dir_start_lookup = 0;
469         inode->i_generation = le32_to_cpu(raw_inode->i_generation);
470
471         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
472             S_ISLNK(inode->i_mode)) {
473                 err = nilfs_bmap_read(ii->i_bmap, raw_inode);
474                 if (err < 0)
475                         return err;
476                 set_bit(NILFS_I_BMAP, &ii->i_state);
477                 /* No lock is needed; iget() ensures it. */
478         }
479         return 0;
480 }
481
482 static int __nilfs_read_inode(struct super_block *sb,
483                               struct nilfs_root *root, unsigned long ino,
484                               struct inode *inode)
485 {
486         struct the_nilfs *nilfs = sb->s_fs_info;
487         struct buffer_head *bh;
488         struct nilfs_inode *raw_inode;
489         int err;
490
491         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
492         err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
493         if (unlikely(err))
494                 goto bad_inode;
495
496         raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
497
498         err = nilfs_read_inode_common(inode, raw_inode);
499         if (err)
500                 goto failed_unmap;
501
502         if (S_ISREG(inode->i_mode)) {
503                 inode->i_op = &nilfs_file_inode_operations;
504                 inode->i_fop = &nilfs_file_operations;
505                 inode->i_mapping->a_ops = &nilfs_aops;
506         } else if (S_ISDIR(inode->i_mode)) {
507                 inode->i_op = &nilfs_dir_inode_operations;
508                 inode->i_fop = &nilfs_dir_operations;
509                 inode->i_mapping->a_ops = &nilfs_aops;
510         } else if (S_ISLNK(inode->i_mode)) {
511                 inode->i_op = &nilfs_symlink_inode_operations;
512                 inode_nohighmem(inode);
513                 inode->i_mapping->a_ops = &nilfs_aops;
514         } else {
515                 inode->i_op = &nilfs_special_inode_operations;
516                 init_special_inode(
517                         inode, inode->i_mode,
518                         huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
519         }
520         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
521         brelse(bh);
522         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
523         nilfs_set_inode_flags(inode);
524         mapping_set_gfp_mask(inode->i_mapping,
525                            mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
526         return 0;
527
528  failed_unmap:
529         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
530         brelse(bh);
531
532  bad_inode:
533         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
534         return err;
535 }
536
537 static int nilfs_iget_test(struct inode *inode, void *opaque)
538 {
539         struct nilfs_iget_args *args = opaque;
540         struct nilfs_inode_info *ii;
541
542         if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
543                 return 0;
544
545         ii = NILFS_I(inode);
546         if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
547                 return !args->for_gc;
548
549         return args->for_gc && args->cno == ii->i_cno;
550 }
551
552 static int nilfs_iget_set(struct inode *inode, void *opaque)
553 {
554         struct nilfs_iget_args *args = opaque;
555
556         inode->i_ino = args->ino;
557         if (args->for_gc) {
558                 NILFS_I(inode)->i_state = BIT(NILFS_I_GCINODE);
559                 NILFS_I(inode)->i_cno = args->cno;
560                 NILFS_I(inode)->i_root = NULL;
561         } else {
562                 if (args->root && args->ino == NILFS_ROOT_INO)
563                         nilfs_get_root(args->root);
564                 NILFS_I(inode)->i_root = args->root;
565         }
566         return 0;
567 }
568
569 struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
570                             unsigned long ino)
571 {
572         struct nilfs_iget_args args = {
573                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
574         };
575
576         return ilookup5(sb, ino, nilfs_iget_test, &args);
577 }
578
579 struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
580                                 unsigned long ino)
581 {
582         struct nilfs_iget_args args = {
583                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
584         };
585
586         return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
587 }
588
589 struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
590                          unsigned long ino)
591 {
592         struct inode *inode;
593         int err;
594
595         inode = nilfs_iget_locked(sb, root, ino);
596         if (unlikely(!inode))
597                 return ERR_PTR(-ENOMEM);
598         if (!(inode->i_state & I_NEW))
599                 return inode;
600
601         err = __nilfs_read_inode(sb, root, ino, inode);
602         if (unlikely(err)) {
603                 iget_failed(inode);
604                 return ERR_PTR(err);
605         }
606         unlock_new_inode(inode);
607         return inode;
608 }
609
610 struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
611                                 __u64 cno)
612 {
613         struct nilfs_iget_args args = {
614                 .ino = ino, .root = NULL, .cno = cno, .for_gc = 1
615         };
616         struct inode *inode;
617         int err;
618
619         inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
620         if (unlikely(!inode))
621                 return ERR_PTR(-ENOMEM);
622         if (!(inode->i_state & I_NEW))
623                 return inode;
624
625         err = nilfs_init_gcinode(inode);
626         if (unlikely(err)) {
627                 iget_failed(inode);
628                 return ERR_PTR(err);
629         }
630         unlock_new_inode(inode);
631         return inode;
632 }
633
634 void nilfs_write_inode_common(struct inode *inode,
635                               struct nilfs_inode *raw_inode, int has_bmap)
636 {
637         struct nilfs_inode_info *ii = NILFS_I(inode);
638
639         raw_inode->i_mode = cpu_to_le16(inode->i_mode);
640         raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
641         raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
642         raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
643         raw_inode->i_size = cpu_to_le64(inode->i_size);
644         raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
645         raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
646         raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
647         raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
648         raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
649
650         raw_inode->i_flags = cpu_to_le32(ii->i_flags);
651         raw_inode->i_generation = cpu_to_le32(inode->i_generation);
652
653         if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
654                 struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
655
656                 /* zero-fill unused portion in the case of super root block */
657                 raw_inode->i_xattr = 0;
658                 raw_inode->i_pad = 0;
659                 memset((void *)raw_inode + sizeof(*raw_inode), 0,
660                        nilfs->ns_inode_size - sizeof(*raw_inode));
661         }
662
663         if (has_bmap)
664                 nilfs_bmap_write(ii->i_bmap, raw_inode);
665         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
666                 raw_inode->i_device_code =
667                         cpu_to_le64(huge_encode_dev(inode->i_rdev));
668         /*
669          * When extending inode, nilfs->ns_inode_size should be checked
670          * for substitutions of appended fields.
671          */
672 }
673
674 void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh, int flags)
675 {
676         ino_t ino = inode->i_ino;
677         struct nilfs_inode_info *ii = NILFS_I(inode);
678         struct inode *ifile = ii->i_root->ifile;
679         struct nilfs_inode *raw_inode;
680
681         raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
682
683         if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
684                 memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
685         if (flags & I_DIRTY_DATASYNC)
686                 set_bit(NILFS_I_INODE_SYNC, &ii->i_state);
687
688         nilfs_write_inode_common(inode, raw_inode, 0);
689                 /*
690                  * XXX: call with has_bmap = 0 is a workaround to avoid
691                  * deadlock of bmap.  This delays update of i_bmap to just
692                  * before writing.
693                  */
694
695         nilfs_ifile_unmap_inode(ifile, ino, ibh);
696 }
697
698 #define NILFS_MAX_TRUNCATE_BLOCKS       16384  /* 64MB for 4KB block */
699
700 static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
701                                 unsigned long from)
702 {
703         __u64 b;
704         int ret;
705
706         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
707                 return;
708 repeat:
709         ret = nilfs_bmap_last_key(ii->i_bmap, &b);
710         if (ret == -ENOENT)
711                 return;
712         else if (ret < 0)
713                 goto failed;
714
715         if (b < from)
716                 return;
717
718         b -= min_t(__u64, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
719         ret = nilfs_bmap_truncate(ii->i_bmap, b);
720         nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
721         if (!ret || (ret == -ENOMEM &&
722                      nilfs_bmap_truncate(ii->i_bmap, b) == 0))
723                 goto repeat;
724
725 failed:
726         nilfs_msg(ii->vfs_inode.i_sb, KERN_WARNING,
727                   "error %d truncating bmap (ino=%lu)", ret,
728                   ii->vfs_inode.i_ino);
729 }
730
731 void nilfs_truncate(struct inode *inode)
732 {
733         unsigned long blkoff;
734         unsigned int blocksize;
735         struct nilfs_transaction_info ti;
736         struct super_block *sb = inode->i_sb;
737         struct nilfs_inode_info *ii = NILFS_I(inode);
738
739         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
740                 return;
741         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
742                 return;
743
744         blocksize = sb->s_blocksize;
745         blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
746         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
747
748         block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
749
750         nilfs_truncate_bmap(ii, blkoff);
751
752         inode->i_mtime = inode->i_ctime = current_time(inode);
753         if (IS_SYNC(inode))
754                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
755
756         nilfs_mark_inode_dirty(inode);
757         nilfs_set_file_dirty(inode, 0);
758         nilfs_transaction_commit(sb);
759         /*
760          * May construct a logical segment and may fail in sync mode.
761          * But truncate has no return value.
762          */
763 }
764
765 static void nilfs_clear_inode(struct inode *inode)
766 {
767         struct nilfs_inode_info *ii = NILFS_I(inode);
768
769         /*
770          * Free resources allocated in nilfs_read_inode(), here.
771          */
772         BUG_ON(!list_empty(&ii->i_dirty));
773         brelse(ii->i_bh);
774         ii->i_bh = NULL;
775
776         if (nilfs_is_metadata_file_inode(inode))
777                 nilfs_mdt_clear(inode);
778
779         if (test_bit(NILFS_I_BMAP, &ii->i_state))
780                 nilfs_bmap_clear(ii->i_bmap);
781
782         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
783
784         if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
785                 nilfs_put_root(ii->i_root);
786 }
787
788 void nilfs_evict_inode(struct inode *inode)
789 {
790         struct nilfs_transaction_info ti;
791         struct super_block *sb = inode->i_sb;
792         struct nilfs_inode_info *ii = NILFS_I(inode);
793         int ret;
794
795         if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
796                 truncate_inode_pages_final(&inode->i_data);
797                 clear_inode(inode);
798                 nilfs_clear_inode(inode);
799                 return;
800         }
801         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
802
803         truncate_inode_pages_final(&inode->i_data);
804
805         /* TODO: some of the following operations may fail.  */
806         nilfs_truncate_bmap(ii, 0);
807         nilfs_mark_inode_dirty(inode);
808         clear_inode(inode);
809
810         ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
811         if (!ret)
812                 atomic64_dec(&ii->i_root->inodes_count);
813
814         nilfs_clear_inode(inode);
815
816         if (IS_SYNC(inode))
817                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
818         nilfs_transaction_commit(sb);
819         /*
820          * May construct a logical segment and may fail in sync mode.
821          * But delete_inode has no return value.
822          */
823 }
824
825 int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
826 {
827         struct nilfs_transaction_info ti;
828         struct inode *inode = d_inode(dentry);
829         struct super_block *sb = inode->i_sb;
830         int err;
831
832         err = setattr_prepare(dentry, iattr);
833         if (err)
834                 return err;
835
836         err = nilfs_transaction_begin(sb, &ti, 0);
837         if (unlikely(err))
838                 return err;
839
840         if ((iattr->ia_valid & ATTR_SIZE) &&
841             iattr->ia_size != i_size_read(inode)) {
842                 inode_dio_wait(inode);
843                 truncate_setsize(inode, iattr->ia_size);
844                 nilfs_truncate(inode);
845         }
846
847         setattr_copy(inode, iattr);
848         mark_inode_dirty(inode);
849
850         if (iattr->ia_valid & ATTR_MODE) {
851                 err = nilfs_acl_chmod(inode);
852                 if (unlikely(err))
853                         goto out_err;
854         }
855
856         return nilfs_transaction_commit(sb);
857
858 out_err:
859         nilfs_transaction_abort(sb);
860         return err;
861 }
862
863 int nilfs_permission(struct inode *inode, int mask)
864 {
865         struct nilfs_root *root = NILFS_I(inode)->i_root;
866
867         if ((mask & MAY_WRITE) && root &&
868             root->cno != NILFS_CPTREE_CURRENT_CNO)
869                 return -EROFS; /* snapshot is not writable */
870
871         return generic_permission(inode, mask);
872 }
873
874 int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
875 {
876         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
877         struct nilfs_inode_info *ii = NILFS_I(inode);
878         int err;
879
880         spin_lock(&nilfs->ns_inode_lock);
881         if (ii->i_bh == NULL) {
882                 spin_unlock(&nilfs->ns_inode_lock);
883                 err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
884                                                   inode->i_ino, pbh);
885                 if (unlikely(err))
886                         return err;
887                 spin_lock(&nilfs->ns_inode_lock);
888                 if (ii->i_bh == NULL)
889                         ii->i_bh = *pbh;
890                 else {
891                         brelse(*pbh);
892                         *pbh = ii->i_bh;
893                 }
894         } else
895                 *pbh = ii->i_bh;
896
897         get_bh(*pbh);
898         spin_unlock(&nilfs->ns_inode_lock);
899         return 0;
900 }
901
902 int nilfs_inode_dirty(struct inode *inode)
903 {
904         struct nilfs_inode_info *ii = NILFS_I(inode);
905         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
906         int ret = 0;
907
908         if (!list_empty(&ii->i_dirty)) {
909                 spin_lock(&nilfs->ns_inode_lock);
910                 ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
911                         test_bit(NILFS_I_BUSY, &ii->i_state);
912                 spin_unlock(&nilfs->ns_inode_lock);
913         }
914         return ret;
915 }
916
917 int nilfs_set_file_dirty(struct inode *inode, unsigned int nr_dirty)
918 {
919         struct nilfs_inode_info *ii = NILFS_I(inode);
920         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
921
922         atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
923
924         if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
925                 return 0;
926
927         spin_lock(&nilfs->ns_inode_lock);
928         if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
929             !test_bit(NILFS_I_BUSY, &ii->i_state)) {
930                 /*
931                  * Because this routine may race with nilfs_dispose_list(),
932                  * we have to check NILFS_I_QUEUED here, too.
933                  */
934                 if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
935                         /*
936                          * This will happen when somebody is freeing
937                          * this inode.
938                          */
939                         nilfs_msg(inode->i_sb, KERN_WARNING,
940                                   "cannot set file dirty (ino=%lu): the file is being freed",
941                                   inode->i_ino);
942                         spin_unlock(&nilfs->ns_inode_lock);
943                         return -EINVAL; /*
944                                          * NILFS_I_DIRTY may remain for
945                                          * freeing inode.
946                                          */
947                 }
948                 list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
949                 set_bit(NILFS_I_QUEUED, &ii->i_state);
950         }
951         spin_unlock(&nilfs->ns_inode_lock);
952         return 0;
953 }
954
955 int __nilfs_mark_inode_dirty(struct inode *inode, int flags)
956 {
957         struct buffer_head *ibh;
958         int err;
959
960         err = nilfs_load_inode_block(inode, &ibh);
961         if (unlikely(err)) {
962                 nilfs_msg(inode->i_sb, KERN_WARNING,
963                           "cannot mark inode dirty (ino=%lu): error %d loading inode block",
964                           inode->i_ino, err);
965                 return err;
966         }
967         nilfs_update_inode(inode, ibh, flags);
968         mark_buffer_dirty(ibh);
969         nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
970         brelse(ibh);
971         return 0;
972 }
973
974 /**
975  * nilfs_dirty_inode - reflect changes on given inode to an inode block.
976  * @inode: inode of the file to be registered.
977  *
978  * nilfs_dirty_inode() loads a inode block containing the specified
979  * @inode and copies data from a nilfs_inode to a corresponding inode
980  * entry in the inode block. This operation is excluded from the segment
981  * construction. This function can be called both as a single operation
982  * and as a part of indivisible file operations.
983  */
984 void nilfs_dirty_inode(struct inode *inode, int flags)
985 {
986         struct nilfs_transaction_info ti;
987         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
988
989         if (is_bad_inode(inode)) {
990                 nilfs_msg(inode->i_sb, KERN_WARNING,
991                           "tried to mark bad_inode dirty. ignored.");
992                 dump_stack();
993                 return;
994         }
995         if (mdi) {
996                 nilfs_mdt_mark_dirty(inode);
997                 return;
998         }
999         nilfs_transaction_begin(inode->i_sb, &ti, 0);
1000         __nilfs_mark_inode_dirty(inode, flags);
1001         nilfs_transaction_commit(inode->i_sb); /* never fails */
1002 }
1003
1004 int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1005                  __u64 start, __u64 len)
1006 {
1007         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1008         __u64 logical = 0, phys = 0, size = 0;
1009         __u32 flags = 0;
1010         loff_t isize;
1011         sector_t blkoff, end_blkoff;
1012         sector_t delalloc_blkoff;
1013         unsigned long delalloc_blklen;
1014         unsigned int blkbits = inode->i_blkbits;
1015         int ret, n;
1016
1017         ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
1018         if (ret)
1019                 return ret;
1020
1021         inode_lock(inode);
1022
1023         isize = i_size_read(inode);
1024
1025         blkoff = start >> blkbits;
1026         end_blkoff = (start + len - 1) >> blkbits;
1027
1028         delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
1029                                                         &delalloc_blkoff);
1030
1031         do {
1032                 __u64 blkphy;
1033                 unsigned int maxblocks;
1034
1035                 if (delalloc_blklen && blkoff == delalloc_blkoff) {
1036                         if (size) {
1037                                 /* End of the current extent */
1038                                 ret = fiemap_fill_next_extent(
1039                                         fieinfo, logical, phys, size, flags);
1040                                 if (ret)
1041                                         break;
1042                         }
1043                         if (blkoff > end_blkoff)
1044                                 break;
1045
1046                         flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
1047                         logical = blkoff << blkbits;
1048                         phys = 0;
1049                         size = delalloc_blklen << blkbits;
1050
1051                         blkoff = delalloc_blkoff + delalloc_blklen;
1052                         delalloc_blklen = nilfs_find_uncommitted_extent(
1053                                 inode, blkoff, &delalloc_blkoff);
1054                         continue;
1055                 }
1056
1057                 /*
1058                  * Limit the number of blocks that we look up so as
1059                  * not to get into the next delayed allocation extent.
1060                  */
1061                 maxblocks = INT_MAX;
1062                 if (delalloc_blklen)
1063                         maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1064                                           maxblocks);
1065                 blkphy = 0;
1066
1067                 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1068                 n = nilfs_bmap_lookup_contig(
1069                         NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1070                 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1071
1072                 if (n < 0) {
1073                         int past_eof;
1074
1075                         if (unlikely(n != -ENOENT))
1076                                 break; /* error */
1077
1078                         /* HOLE */
1079                         blkoff++;
1080                         past_eof = ((blkoff << blkbits) >= isize);
1081
1082                         if (size) {
1083                                 /* End of the current extent */
1084
1085                                 if (past_eof)
1086                                         flags |= FIEMAP_EXTENT_LAST;
1087
1088                                 ret = fiemap_fill_next_extent(
1089                                         fieinfo, logical, phys, size, flags);
1090                                 if (ret)
1091                                         break;
1092                                 size = 0;
1093                         }
1094                         if (blkoff > end_blkoff || past_eof)
1095                                 break;
1096                 } else {
1097                         if (size) {
1098                                 if (phys && blkphy << blkbits == phys + size) {
1099                                         /* The current extent goes on */
1100                                         size += n << blkbits;
1101                                 } else {
1102                                         /* Terminate the current extent */
1103                                         ret = fiemap_fill_next_extent(
1104                                                 fieinfo, logical, phys, size,
1105                                                 flags);
1106                                         if (ret || blkoff > end_blkoff)
1107                                                 break;
1108
1109                                         /* Start another extent */
1110                                         flags = FIEMAP_EXTENT_MERGED;
1111                                         logical = blkoff << blkbits;
1112                                         phys = blkphy << blkbits;
1113                                         size = n << blkbits;
1114                                 }
1115                         } else {
1116                                 /* Start a new extent */
1117                                 flags = FIEMAP_EXTENT_MERGED;
1118                                 logical = blkoff << blkbits;
1119                                 phys = blkphy << blkbits;
1120                                 size = n << blkbits;
1121                         }
1122                         blkoff += n;
1123                 }
1124                 cond_resched();
1125         } while (true);
1126
1127         /* If ret is 1 then we just hit the end of the extent array */
1128         if (ret == 1)
1129                 ret = 0;
1130
1131         inode_unlock(inode);
1132         return ret;
1133 }