nilfs2: add truncation routine of segment usage file
[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 void nilfs_inode_add_blocks(struct inode *inode, int n)
45 {
46         struct nilfs_root *root = NILFS_I(inode)->i_root;
47
48         inode_add_bytes(inode, (1 << inode->i_blkbits) * n);
49         if (root)
50                 atomic_add(n, &root->blocks_count);
51 }
52
53 void nilfs_inode_sub_blocks(struct inode *inode, int n)
54 {
55         struct nilfs_root *root = NILFS_I(inode)->i_root;
56
57         inode_sub_bytes(inode, (1 << inode->i_blkbits) * n);
58         if (root)
59                 atomic_sub(n, &root->blocks_count);
60 }
61
62 /**
63  * nilfs_get_block() - get a file block on the filesystem (callback function)
64  * @inode - inode struct of the target file
65  * @blkoff - file block number
66  * @bh_result - buffer head to be mapped on
67  * @create - indicate whether allocating the block or not when it has not
68  *      been allocated yet.
69  *
70  * This function does not issue actual read request of the specified data
71  * block. It is done by VFS.
72  */
73 int nilfs_get_block(struct inode *inode, sector_t blkoff,
74                     struct buffer_head *bh_result, int create)
75 {
76         struct nilfs_inode_info *ii = NILFS_I(inode);
77         __u64 blknum = 0;
78         int err = 0, ret;
79         struct inode *dat = NILFS_I_NILFS(inode)->ns_dat;
80         unsigned maxblocks = bh_result->b_size >> inode->i_blkbits;
81
82         down_read(&NILFS_MDT(dat)->mi_sem);
83         ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
84         up_read(&NILFS_MDT(dat)->mi_sem);
85         if (ret >= 0) { /* found */
86                 map_bh(bh_result, inode->i_sb, blknum);
87                 if (ret > 0)
88                         bh_result->b_size = (ret << inode->i_blkbits);
89                 goto out;
90         }
91         /* data block was not found */
92         if (ret == -ENOENT && create) {
93                 struct nilfs_transaction_info ti;
94
95                 bh_result->b_blocknr = 0;
96                 err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
97                 if (unlikely(err))
98                         goto out;
99                 err = nilfs_bmap_insert(ii->i_bmap, (unsigned long)blkoff,
100                                         (unsigned long)bh_result);
101                 if (unlikely(err != 0)) {
102                         if (err == -EEXIST) {
103                                 /*
104                                  * The get_block() function could be called
105                                  * from multiple callers for an inode.
106                                  * However, the page having this block must
107                                  * be locked in this case.
108                                  */
109                                 printk(KERN_WARNING
110                                        "nilfs_get_block: a race condition "
111                                        "while inserting a data block. "
112                                        "(inode number=%lu, file block "
113                                        "offset=%llu)\n",
114                                        inode->i_ino,
115                                        (unsigned long long)blkoff);
116                                 err = 0;
117                         }
118                         nilfs_transaction_abort(inode->i_sb);
119                         goto out;
120                 }
121                 nilfs_mark_inode_dirty(inode);
122                 nilfs_transaction_commit(inode->i_sb); /* never fails */
123                 /* Error handling should be detailed */
124                 set_buffer_new(bh_result);
125                 set_buffer_delay(bh_result);
126                 map_bh(bh_result, inode->i_sb, 0); /* dbn must be changed
127                                                       to proper value */
128         } else if (ret == -ENOENT) {
129                 /* not found is not error (e.g. hole); must return without
130                    the mapped state flag. */
131                 ;
132         } else {
133                 err = ret;
134         }
135
136  out:
137         return err;
138 }
139
140 /**
141  * nilfs_readpage() - implement readpage() method of nilfs_aops {}
142  * address_space_operations.
143  * @file - file struct of the file to be read
144  * @page - the page to be read
145  */
146 static int nilfs_readpage(struct file *file, struct page *page)
147 {
148         return mpage_readpage(page, nilfs_get_block);
149 }
150
151 /**
152  * nilfs_readpages() - implement readpages() method of nilfs_aops {}
153  * address_space_operations.
154  * @file - file struct of the file to be read
155  * @mapping - address_space struct used for reading multiple pages
156  * @pages - the pages to be read
157  * @nr_pages - number of pages to be read
158  */
159 static int nilfs_readpages(struct file *file, struct address_space *mapping,
160                            struct list_head *pages, unsigned nr_pages)
161 {
162         return mpage_readpages(mapping, pages, nr_pages, nilfs_get_block);
163 }
164
165 static int nilfs_writepages(struct address_space *mapping,
166                             struct writeback_control *wbc)
167 {
168         struct inode *inode = mapping->host;
169         int err = 0;
170
171         if (wbc->sync_mode == WB_SYNC_ALL)
172                 err = nilfs_construct_dsync_segment(inode->i_sb, inode,
173                                                     wbc->range_start,
174                                                     wbc->range_end);
175         return err;
176 }
177
178 static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
179 {
180         struct inode *inode = page->mapping->host;
181         int err;
182
183         redirty_page_for_writepage(wbc, page);
184         unlock_page(page);
185
186         if (wbc->sync_mode == WB_SYNC_ALL) {
187                 err = nilfs_construct_segment(inode->i_sb);
188                 if (unlikely(err))
189                         return err;
190         } else if (wbc->for_reclaim)
191                 nilfs_flush_segment(inode->i_sb, inode->i_ino);
192
193         return 0;
194 }
195
196 static int nilfs_set_page_dirty(struct page *page)
197 {
198         int ret = __set_page_dirty_buffers(page);
199
200         if (ret) {
201                 struct inode *inode = page->mapping->host;
202                 unsigned nr_dirty = 1 << (PAGE_SHIFT - inode->i_blkbits);
203
204                 nilfs_set_file_dirty(inode, nr_dirty);
205         }
206         return ret;
207 }
208
209 static int nilfs_write_begin(struct file *file, struct address_space *mapping,
210                              loff_t pos, unsigned len, unsigned flags,
211                              struct page **pagep, void **fsdata)
212
213 {
214         struct inode *inode = mapping->host;
215         int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
216
217         if (unlikely(err))
218                 return err;
219
220         err = block_write_begin(mapping, pos, len, flags, pagep,
221                                 nilfs_get_block);
222         if (unlikely(err)) {
223                 loff_t isize = mapping->host->i_size;
224                 if (pos + len > isize)
225                         vmtruncate(mapping->host, isize);
226
227                 nilfs_transaction_abort(inode->i_sb);
228         }
229         return err;
230 }
231
232 static int nilfs_write_end(struct file *file, struct address_space *mapping,
233                            loff_t pos, unsigned len, unsigned copied,
234                            struct page *page, void *fsdata)
235 {
236         struct inode *inode = mapping->host;
237         unsigned start = pos & (PAGE_CACHE_SIZE - 1);
238         unsigned nr_dirty;
239         int err;
240
241         nr_dirty = nilfs_page_count_clean_buffers(page, start,
242                                                   start + copied);
243         copied = generic_write_end(file, mapping, pos, len, copied, page,
244                                    fsdata);
245         nilfs_set_file_dirty(inode, nr_dirty);
246         err = nilfs_transaction_commit(inode->i_sb);
247         return err ? : copied;
248 }
249
250 static ssize_t
251 nilfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
252                 loff_t offset, unsigned long nr_segs)
253 {
254         struct file *file = iocb->ki_filp;
255         struct inode *inode = file->f_mapping->host;
256         ssize_t size;
257
258         if (rw == WRITE)
259                 return 0;
260
261         /* Needs synchronization with the cleaner */
262         size = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
263                                   offset, nr_segs, nilfs_get_block, NULL);
264
265         /*
266          * In case of error extending write may have instantiated a few
267          * blocks outside i_size. Trim these off again.
268          */
269         if (unlikely((rw & WRITE) && size < 0)) {
270                 loff_t isize = i_size_read(inode);
271                 loff_t end = offset + iov_length(iov, nr_segs);
272
273                 if (end > isize)
274                         vmtruncate(inode, isize);
275         }
276
277         return size;
278 }
279
280 const struct address_space_operations nilfs_aops = {
281         .writepage              = nilfs_writepage,
282         .readpage               = nilfs_readpage,
283         .writepages             = nilfs_writepages,
284         .set_page_dirty         = nilfs_set_page_dirty,
285         .readpages              = nilfs_readpages,
286         .write_begin            = nilfs_write_begin,
287         .write_end              = nilfs_write_end,
288         /* .releasepage         = nilfs_releasepage, */
289         .invalidatepage         = block_invalidatepage,
290         .direct_IO              = nilfs_direct_IO,
291         .is_partially_uptodate  = block_is_partially_uptodate,
292 };
293
294 struct inode *nilfs_new_inode(struct inode *dir, int mode)
295 {
296         struct super_block *sb = dir->i_sb;
297         struct the_nilfs *nilfs = sb->s_fs_info;
298         struct inode *inode;
299         struct nilfs_inode_info *ii;
300         struct nilfs_root *root;
301         int err = -ENOMEM;
302         ino_t ino;
303
304         inode = new_inode(sb);
305         if (unlikely(!inode))
306                 goto failed;
307
308         mapping_set_gfp_mask(inode->i_mapping,
309                              mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
310
311         root = NILFS_I(dir)->i_root;
312         ii = NILFS_I(inode);
313         ii->i_state = 1 << NILFS_I_NEW;
314         ii->i_root = root;
315
316         err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
317         if (unlikely(err))
318                 goto failed_ifile_create_inode;
319         /* reference count of i_bh inherits from nilfs_mdt_read_block() */
320
321         atomic_inc(&root->inodes_count);
322         inode_init_owner(inode, dir, mode);
323         inode->i_ino = ino;
324         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
325
326         if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
327                 err = nilfs_bmap_read(ii->i_bmap, NULL);
328                 if (err < 0)
329                         goto failed_bmap;
330
331                 set_bit(NILFS_I_BMAP, &ii->i_state);
332                 /* No lock is needed; iget() ensures it. */
333         }
334
335         ii->i_flags = nilfs_mask_flags(
336                 mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
337
338         /* ii->i_file_acl = 0; */
339         /* ii->i_dir_acl = 0; */
340         ii->i_dir_start_lookup = 0;
341         nilfs_set_inode_flags(inode);
342         spin_lock(&nilfs->ns_next_gen_lock);
343         inode->i_generation = nilfs->ns_next_generation++;
344         spin_unlock(&nilfs->ns_next_gen_lock);
345         insert_inode_hash(inode);
346
347         err = nilfs_init_acl(inode, dir);
348         if (unlikely(err))
349                 goto failed_acl; /* never occur. When supporting
350                                     nilfs_init_acl(), proper cancellation of
351                                     above jobs should be considered */
352
353         return inode;
354
355  failed_acl:
356  failed_bmap:
357         inode->i_nlink = 0;
358         iput(inode);  /* raw_inode will be deleted through
359                          generic_delete_inode() */
360         goto failed;
361
362  failed_ifile_create_inode:
363         make_bad_inode(inode);
364         iput(inode);  /* if i_nlink == 1, generic_forget_inode() will be
365                          called */
366  failed:
367         return ERR_PTR(err);
368 }
369
370 void nilfs_set_inode_flags(struct inode *inode)
371 {
372         unsigned int flags = NILFS_I(inode)->i_flags;
373
374         inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |
375                             S_DIRSYNC);
376         if (flags & FS_SYNC_FL)
377                 inode->i_flags |= S_SYNC;
378         if (flags & FS_APPEND_FL)
379                 inode->i_flags |= S_APPEND;
380         if (flags & FS_IMMUTABLE_FL)
381                 inode->i_flags |= S_IMMUTABLE;
382         if (flags & FS_NOATIME_FL)
383                 inode->i_flags |= S_NOATIME;
384         if (flags & FS_DIRSYNC_FL)
385                 inode->i_flags |= S_DIRSYNC;
386         mapping_set_gfp_mask(inode->i_mapping,
387                              mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
388 }
389
390 int nilfs_read_inode_common(struct inode *inode,
391                             struct nilfs_inode *raw_inode)
392 {
393         struct nilfs_inode_info *ii = NILFS_I(inode);
394         int err;
395
396         inode->i_mode = le16_to_cpu(raw_inode->i_mode);
397         inode->i_uid = (uid_t)le32_to_cpu(raw_inode->i_uid);
398         inode->i_gid = (gid_t)le32_to_cpu(raw_inode->i_gid);
399         inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
400         inode->i_size = le64_to_cpu(raw_inode->i_size);
401         inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
402         inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
403         inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
404         inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
405         inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
406         inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
407         if (inode->i_nlink == 0 && inode->i_mode == 0)
408                 return -EINVAL; /* this inode is deleted */
409
410         inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
411         ii->i_flags = le32_to_cpu(raw_inode->i_flags);
412 #if 0
413         ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
414         ii->i_dir_acl = S_ISREG(inode->i_mode) ?
415                 0 : le32_to_cpu(raw_inode->i_dir_acl);
416 #endif
417         ii->i_dir_start_lookup = 0;
418         inode->i_generation = le32_to_cpu(raw_inode->i_generation);
419
420         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
421             S_ISLNK(inode->i_mode)) {
422                 err = nilfs_bmap_read(ii->i_bmap, raw_inode);
423                 if (err < 0)
424                         return err;
425                 set_bit(NILFS_I_BMAP, &ii->i_state);
426                 /* No lock is needed; iget() ensures it. */
427         }
428         return 0;
429 }
430
431 static int __nilfs_read_inode(struct super_block *sb,
432                               struct nilfs_root *root, unsigned long ino,
433                               struct inode *inode)
434 {
435         struct the_nilfs *nilfs = sb->s_fs_info;
436         struct buffer_head *bh;
437         struct nilfs_inode *raw_inode;
438         int err;
439
440         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
441         err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
442         if (unlikely(err))
443                 goto bad_inode;
444
445         raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
446
447         err = nilfs_read_inode_common(inode, raw_inode);
448         if (err)
449                 goto failed_unmap;
450
451         if (S_ISREG(inode->i_mode)) {
452                 inode->i_op = &nilfs_file_inode_operations;
453                 inode->i_fop = &nilfs_file_operations;
454                 inode->i_mapping->a_ops = &nilfs_aops;
455         } else if (S_ISDIR(inode->i_mode)) {
456                 inode->i_op = &nilfs_dir_inode_operations;
457                 inode->i_fop = &nilfs_dir_operations;
458                 inode->i_mapping->a_ops = &nilfs_aops;
459         } else if (S_ISLNK(inode->i_mode)) {
460                 inode->i_op = &nilfs_symlink_inode_operations;
461                 inode->i_mapping->a_ops = &nilfs_aops;
462         } else {
463                 inode->i_op = &nilfs_special_inode_operations;
464                 init_special_inode(
465                         inode, inode->i_mode,
466                         huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
467         }
468         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
469         brelse(bh);
470         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
471         nilfs_set_inode_flags(inode);
472         return 0;
473
474  failed_unmap:
475         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
476         brelse(bh);
477
478  bad_inode:
479         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
480         return err;
481 }
482
483 static int nilfs_iget_test(struct inode *inode, void *opaque)
484 {
485         struct nilfs_iget_args *args = opaque;
486         struct nilfs_inode_info *ii;
487
488         if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
489                 return 0;
490
491         ii = NILFS_I(inode);
492         if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
493                 return !args->for_gc;
494
495         return args->for_gc && args->cno == ii->i_cno;
496 }
497
498 static int nilfs_iget_set(struct inode *inode, void *opaque)
499 {
500         struct nilfs_iget_args *args = opaque;
501
502         inode->i_ino = args->ino;
503         if (args->for_gc) {
504                 NILFS_I(inode)->i_state = 1 << NILFS_I_GCINODE;
505                 NILFS_I(inode)->i_cno = args->cno;
506                 NILFS_I(inode)->i_root = NULL;
507         } else {
508                 if (args->root && args->ino == NILFS_ROOT_INO)
509                         nilfs_get_root(args->root);
510                 NILFS_I(inode)->i_root = args->root;
511         }
512         return 0;
513 }
514
515 struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
516                             unsigned long ino)
517 {
518         struct nilfs_iget_args args = {
519                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
520         };
521
522         return ilookup5(sb, ino, nilfs_iget_test, &args);
523 }
524
525 struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
526                                 unsigned long ino)
527 {
528         struct nilfs_iget_args args = {
529                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
530         };
531
532         return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
533 }
534
535 struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
536                          unsigned long ino)
537 {
538         struct inode *inode;
539         int err;
540
541         inode = nilfs_iget_locked(sb, root, ino);
542         if (unlikely(!inode))
543                 return ERR_PTR(-ENOMEM);
544         if (!(inode->i_state & I_NEW))
545                 return inode;
546
547         err = __nilfs_read_inode(sb, root, ino, inode);
548         if (unlikely(err)) {
549                 iget_failed(inode);
550                 return ERR_PTR(err);
551         }
552         unlock_new_inode(inode);
553         return inode;
554 }
555
556 struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
557                                 __u64 cno)
558 {
559         struct nilfs_iget_args args = {
560                 .ino = ino, .root = NULL, .cno = cno, .for_gc = 1
561         };
562         struct inode *inode;
563         int err;
564
565         inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
566         if (unlikely(!inode))
567                 return ERR_PTR(-ENOMEM);
568         if (!(inode->i_state & I_NEW))
569                 return inode;
570
571         err = nilfs_init_gcinode(inode);
572         if (unlikely(err)) {
573                 iget_failed(inode);
574                 return ERR_PTR(err);
575         }
576         unlock_new_inode(inode);
577         return inode;
578 }
579
580 void nilfs_write_inode_common(struct inode *inode,
581                               struct nilfs_inode *raw_inode, int has_bmap)
582 {
583         struct nilfs_inode_info *ii = NILFS_I(inode);
584
585         raw_inode->i_mode = cpu_to_le16(inode->i_mode);
586         raw_inode->i_uid = cpu_to_le32(inode->i_uid);
587         raw_inode->i_gid = cpu_to_le32(inode->i_gid);
588         raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
589         raw_inode->i_size = cpu_to_le64(inode->i_size);
590         raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
591         raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
592         raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
593         raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
594         raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
595
596         raw_inode->i_flags = cpu_to_le32(ii->i_flags);
597         raw_inode->i_generation = cpu_to_le32(inode->i_generation);
598
599         if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
600                 struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
601
602                 /* zero-fill unused portion in the case of super root block */
603                 raw_inode->i_xattr = 0;
604                 raw_inode->i_pad = 0;
605                 memset((void *)raw_inode + sizeof(*raw_inode), 0,
606                        nilfs->ns_inode_size - sizeof(*raw_inode));
607         }
608
609         if (has_bmap)
610                 nilfs_bmap_write(ii->i_bmap, raw_inode);
611         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
612                 raw_inode->i_device_code =
613                         cpu_to_le64(huge_encode_dev(inode->i_rdev));
614         /* When extending inode, nilfs->ns_inode_size should be checked
615            for substitutions of appended fields */
616 }
617
618 void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh)
619 {
620         ino_t ino = inode->i_ino;
621         struct nilfs_inode_info *ii = NILFS_I(inode);
622         struct inode *ifile = ii->i_root->ifile;
623         struct nilfs_inode *raw_inode;
624
625         raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
626
627         if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
628                 memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
629         set_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
630
631         nilfs_write_inode_common(inode, raw_inode, 0);
632                 /* XXX: call with has_bmap = 0 is a workaround to avoid
633                    deadlock of bmap. This delays update of i_bmap to just
634                    before writing */
635         nilfs_ifile_unmap_inode(ifile, ino, ibh);
636 }
637
638 #define NILFS_MAX_TRUNCATE_BLOCKS       16384  /* 64MB for 4KB block */
639
640 static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
641                                 unsigned long from)
642 {
643         unsigned long b;
644         int ret;
645
646         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
647                 return;
648 repeat:
649         ret = nilfs_bmap_last_key(ii->i_bmap, &b);
650         if (ret == -ENOENT)
651                 return;
652         else if (ret < 0)
653                 goto failed;
654
655         if (b < from)
656                 return;
657
658         b -= min_t(unsigned long, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
659         ret = nilfs_bmap_truncate(ii->i_bmap, b);
660         nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
661         if (!ret || (ret == -ENOMEM &&
662                      nilfs_bmap_truncate(ii->i_bmap, b) == 0))
663                 goto repeat;
664
665 failed:
666         nilfs_warning(ii->vfs_inode.i_sb, __func__,
667                       "failed to truncate bmap (ino=%lu, err=%d)",
668                       ii->vfs_inode.i_ino, ret);
669 }
670
671 void nilfs_truncate(struct inode *inode)
672 {
673         unsigned long blkoff;
674         unsigned int blocksize;
675         struct nilfs_transaction_info ti;
676         struct super_block *sb = inode->i_sb;
677         struct nilfs_inode_info *ii = NILFS_I(inode);
678
679         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
680                 return;
681         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
682                 return;
683
684         blocksize = sb->s_blocksize;
685         blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
686         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
687
688         block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
689
690         nilfs_truncate_bmap(ii, blkoff);
691
692         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
693         if (IS_SYNC(inode))
694                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
695
696         nilfs_mark_inode_dirty(inode);
697         nilfs_set_file_dirty(inode, 0);
698         nilfs_transaction_commit(sb);
699         /* May construct a logical segment and may fail in sync mode.
700            But truncate has no return value. */
701 }
702
703 static void nilfs_clear_inode(struct inode *inode)
704 {
705         struct nilfs_inode_info *ii = NILFS_I(inode);
706         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
707
708         /*
709          * Free resources allocated in nilfs_read_inode(), here.
710          */
711         BUG_ON(!list_empty(&ii->i_dirty));
712         brelse(ii->i_bh);
713         ii->i_bh = NULL;
714
715         if (mdi && mdi->mi_palloc_cache)
716                 nilfs_palloc_destroy_cache(inode);
717
718         if (test_bit(NILFS_I_BMAP, &ii->i_state))
719                 nilfs_bmap_clear(ii->i_bmap);
720
721         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
722
723         if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
724                 nilfs_put_root(ii->i_root);
725 }
726
727 void nilfs_evict_inode(struct inode *inode)
728 {
729         struct nilfs_transaction_info ti;
730         struct super_block *sb = inode->i_sb;
731         struct nilfs_inode_info *ii = NILFS_I(inode);
732         int ret;
733
734         if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
735                 if (inode->i_data.nrpages)
736                         truncate_inode_pages(&inode->i_data, 0);
737                 end_writeback(inode);
738                 nilfs_clear_inode(inode);
739                 return;
740         }
741         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
742
743         if (inode->i_data.nrpages)
744                 truncate_inode_pages(&inode->i_data, 0);
745
746         /* TODO: some of the following operations may fail.  */
747         nilfs_truncate_bmap(ii, 0);
748         nilfs_mark_inode_dirty(inode);
749         end_writeback(inode);
750
751         ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
752         if (!ret)
753                 atomic_dec(&ii->i_root->inodes_count);
754
755         nilfs_clear_inode(inode);
756
757         if (IS_SYNC(inode))
758                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
759         nilfs_transaction_commit(sb);
760         /* May construct a logical segment and may fail in sync mode.
761            But delete_inode has no return value. */
762 }
763
764 int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
765 {
766         struct nilfs_transaction_info ti;
767         struct inode *inode = dentry->d_inode;
768         struct super_block *sb = inode->i_sb;
769         int err;
770
771         err = inode_change_ok(inode, iattr);
772         if (err)
773                 return err;
774
775         err = nilfs_transaction_begin(sb, &ti, 0);
776         if (unlikely(err))
777                 return err;
778
779         if ((iattr->ia_valid & ATTR_SIZE) &&
780             iattr->ia_size != i_size_read(inode)) {
781                 err = vmtruncate(inode, iattr->ia_size);
782                 if (unlikely(err))
783                         goto out_err;
784         }
785
786         setattr_copy(inode, iattr);
787         mark_inode_dirty(inode);
788
789         if (iattr->ia_valid & ATTR_MODE) {
790                 err = nilfs_acl_chmod(inode);
791                 if (unlikely(err))
792                         goto out_err;
793         }
794
795         return nilfs_transaction_commit(sb);
796
797 out_err:
798         nilfs_transaction_abort(sb);
799         return err;
800 }
801
802 int nilfs_permission(struct inode *inode, int mask, unsigned int flags)
803 {
804         struct nilfs_root *root;
805
806         if (flags & IPERM_FLAG_RCU)
807                 return -ECHILD;
808
809         root = NILFS_I(inode)->i_root;
810         if ((mask & MAY_WRITE) && root &&
811             root->cno != NILFS_CPTREE_CURRENT_CNO)
812                 return -EROFS; /* snapshot is not writable */
813
814         return generic_permission(inode, mask, flags, NULL);
815 }
816
817 int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
818 {
819         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
820         struct nilfs_inode_info *ii = NILFS_I(inode);
821         int err;
822
823         spin_lock(&nilfs->ns_inode_lock);
824         if (ii->i_bh == NULL) {
825                 spin_unlock(&nilfs->ns_inode_lock);
826                 err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
827                                                   inode->i_ino, pbh);
828                 if (unlikely(err))
829                         return err;
830                 spin_lock(&nilfs->ns_inode_lock);
831                 if (ii->i_bh == NULL)
832                         ii->i_bh = *pbh;
833                 else {
834                         brelse(*pbh);
835                         *pbh = ii->i_bh;
836                 }
837         } else
838                 *pbh = ii->i_bh;
839
840         get_bh(*pbh);
841         spin_unlock(&nilfs->ns_inode_lock);
842         return 0;
843 }
844
845 int nilfs_inode_dirty(struct inode *inode)
846 {
847         struct nilfs_inode_info *ii = NILFS_I(inode);
848         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
849         int ret = 0;
850
851         if (!list_empty(&ii->i_dirty)) {
852                 spin_lock(&nilfs->ns_inode_lock);
853                 ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
854                         test_bit(NILFS_I_BUSY, &ii->i_state);
855                 spin_unlock(&nilfs->ns_inode_lock);
856         }
857         return ret;
858 }
859
860 int nilfs_set_file_dirty(struct inode *inode, unsigned nr_dirty)
861 {
862         struct nilfs_inode_info *ii = NILFS_I(inode);
863         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
864
865         atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
866
867         if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
868                 return 0;
869
870         spin_lock(&nilfs->ns_inode_lock);
871         if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
872             !test_bit(NILFS_I_BUSY, &ii->i_state)) {
873                 /* Because this routine may race with nilfs_dispose_list(),
874                    we have to check NILFS_I_QUEUED here, too. */
875                 if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
876                         /* This will happen when somebody is freeing
877                            this inode. */
878                         nilfs_warning(inode->i_sb, __func__,
879                                       "cannot get inode (ino=%lu)\n",
880                                       inode->i_ino);
881                         spin_unlock(&nilfs->ns_inode_lock);
882                         return -EINVAL; /* NILFS_I_DIRTY may remain for
883                                            freeing inode */
884                 }
885                 list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
886                 set_bit(NILFS_I_QUEUED, &ii->i_state);
887         }
888         spin_unlock(&nilfs->ns_inode_lock);
889         return 0;
890 }
891
892 int nilfs_mark_inode_dirty(struct inode *inode)
893 {
894         struct buffer_head *ibh;
895         int err;
896
897         err = nilfs_load_inode_block(inode, &ibh);
898         if (unlikely(err)) {
899                 nilfs_warning(inode->i_sb, __func__,
900                               "failed to reget inode block.\n");
901                 return err;
902         }
903         nilfs_update_inode(inode, ibh);
904         nilfs_mdt_mark_buffer_dirty(ibh);
905         nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
906         brelse(ibh);
907         return 0;
908 }
909
910 /**
911  * nilfs_dirty_inode - reflect changes on given inode to an inode block.
912  * @inode: inode of the file to be registered.
913  *
914  * nilfs_dirty_inode() loads a inode block containing the specified
915  * @inode and copies data from a nilfs_inode to a corresponding inode
916  * entry in the inode block. This operation is excluded from the segment
917  * construction. This function can be called both as a single operation
918  * and as a part of indivisible file operations.
919  */
920 void nilfs_dirty_inode(struct inode *inode)
921 {
922         struct nilfs_transaction_info ti;
923         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
924
925         if (is_bad_inode(inode)) {
926                 nilfs_warning(inode->i_sb, __func__,
927                               "tried to mark bad_inode dirty. ignored.\n");
928                 dump_stack();
929                 return;
930         }
931         if (mdi) {
932                 nilfs_mdt_mark_dirty(inode);
933                 return;
934         }
935         nilfs_transaction_begin(inode->i_sb, &ti, 0);
936         nilfs_mark_inode_dirty(inode);
937         nilfs_transaction_commit(inode->i_sb); /* never fails */
938 }
939
940 int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
941                  __u64 start, __u64 len)
942 {
943         struct the_nilfs *nilfs = NILFS_I_NILFS(inode);
944         __u64 logical = 0, phys = 0, size = 0;
945         __u32 flags = 0;
946         loff_t isize;
947         sector_t blkoff, end_blkoff;
948         sector_t delalloc_blkoff;
949         unsigned long delalloc_blklen;
950         unsigned int blkbits = inode->i_blkbits;
951         int ret, n;
952
953         ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
954         if (ret)
955                 return ret;
956
957         mutex_lock(&inode->i_mutex);
958
959         isize = i_size_read(inode);
960
961         blkoff = start >> blkbits;
962         end_blkoff = (start + len - 1) >> blkbits;
963
964         delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
965                                                         &delalloc_blkoff);
966
967         do {
968                 __u64 blkphy;
969                 unsigned int maxblocks;
970
971                 if (delalloc_blklen && blkoff == delalloc_blkoff) {
972                         if (size) {
973                                 /* End of the current extent */
974                                 ret = fiemap_fill_next_extent(
975                                         fieinfo, logical, phys, size, flags);
976                                 if (ret)
977                                         break;
978                         }
979                         if (blkoff > end_blkoff)
980                                 break;
981
982                         flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
983                         logical = blkoff << blkbits;
984                         phys = 0;
985                         size = delalloc_blklen << blkbits;
986
987                         blkoff = delalloc_blkoff + delalloc_blklen;
988                         delalloc_blklen = nilfs_find_uncommitted_extent(
989                                 inode, blkoff, &delalloc_blkoff);
990                         continue;
991                 }
992
993                 /*
994                  * Limit the number of blocks that we look up so as
995                  * not to get into the next delayed allocation extent.
996                  */
997                 maxblocks = INT_MAX;
998                 if (delalloc_blklen)
999                         maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1000                                           maxblocks);
1001                 blkphy = 0;
1002
1003                 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1004                 n = nilfs_bmap_lookup_contig(
1005                         NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1006                 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1007
1008                 if (n < 0) {
1009                         int past_eof;
1010
1011                         if (unlikely(n != -ENOENT))
1012                                 break; /* error */
1013
1014                         /* HOLE */
1015                         blkoff++;
1016                         past_eof = ((blkoff << blkbits) >= isize);
1017
1018                         if (size) {
1019                                 /* End of the current extent */
1020
1021                                 if (past_eof)
1022                                         flags |= FIEMAP_EXTENT_LAST;
1023
1024                                 ret = fiemap_fill_next_extent(
1025                                         fieinfo, logical, phys, size, flags);
1026                                 if (ret)
1027                                         break;
1028                                 size = 0;
1029                         }
1030                         if (blkoff > end_blkoff || past_eof)
1031                                 break;
1032                 } else {
1033                         if (size) {
1034                                 if (phys && blkphy << blkbits == phys + size) {
1035                                         /* The current extent goes on */
1036                                         size += n << blkbits;
1037                                 } else {
1038                                         /* Terminate the current extent */
1039                                         ret = fiemap_fill_next_extent(
1040                                                 fieinfo, logical, phys, size,
1041                                                 flags);
1042                                         if (ret || blkoff > end_blkoff)
1043                                                 break;
1044
1045                                         /* Start another extent */
1046                                         flags = FIEMAP_EXTENT_MERGED;
1047                                         logical = blkoff << blkbits;
1048                                         phys = blkphy << blkbits;
1049                                         size = n << blkbits;
1050                                 }
1051                         } else {
1052                                 /* Start a new extent */
1053                                 flags = FIEMAP_EXTENT_MERGED;
1054                                 logical = blkoff << blkbits;
1055                                 phys = blkphy << blkbits;
1056                                 size = n << blkbits;
1057                         }
1058                         blkoff += n;
1059                 }
1060                 cond_resched();
1061         } while (true);
1062
1063         /* If ret is 1 then we just hit the end of the extent array */
1064         if (ret == 1)
1065                 ret = 0;
1066
1067         mutex_unlock(&inode->i_mutex);
1068         return ret;
1069 }