nilfs2: move mount options to nilfs object
[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         .sync_page              = block_sync_page,
284         .writepages             = nilfs_writepages,
285         .set_page_dirty         = nilfs_set_page_dirty,
286         .readpages              = nilfs_readpages,
287         .write_begin            = nilfs_write_begin,
288         .write_end              = nilfs_write_end,
289         /* .releasepage         = nilfs_releasepage, */
290         .invalidatepage         = block_invalidatepage,
291         .direct_IO              = nilfs_direct_IO,
292         .is_partially_uptodate  = block_is_partially_uptodate,
293 };
294
295 struct inode *nilfs_new_inode(struct inode *dir, int mode)
296 {
297         struct super_block *sb = dir->i_sb;
298         struct nilfs_sb_info *sbi = NILFS_SB(sb);
299         struct inode *inode;
300         struct nilfs_inode_info *ii;
301         struct nilfs_root *root;
302         int err = -ENOMEM;
303         ino_t ino;
304
305         inode = new_inode(sb);
306         if (unlikely(!inode))
307                 goto failed;
308
309         mapping_set_gfp_mask(inode->i_mapping,
310                              mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
311
312         root = NILFS_I(dir)->i_root;
313         ii = NILFS_I(inode);
314         ii->i_state = 1 << NILFS_I_NEW;
315         ii->i_root = root;
316
317         err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
318         if (unlikely(err))
319                 goto failed_ifile_create_inode;
320         /* reference count of i_bh inherits from nilfs_mdt_read_block() */
321
322         atomic_inc(&root->inodes_count);
323         inode_init_owner(inode, dir, mode);
324         inode->i_ino = ino;
325         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
326
327         if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
328                 err = nilfs_bmap_read(ii->i_bmap, NULL);
329                 if (err < 0)
330                         goto failed_bmap;
331
332                 set_bit(NILFS_I_BMAP, &ii->i_state);
333                 /* No lock is needed; iget() ensures it. */
334         }
335
336         ii->i_flags = nilfs_mask_flags(
337                 mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
338
339         /* ii->i_file_acl = 0; */
340         /* ii->i_dir_acl = 0; */
341         ii->i_dir_start_lookup = 0;
342         nilfs_set_inode_flags(inode);
343         spin_lock(&sbi->s_next_gen_lock);
344         inode->i_generation = sbi->s_next_generation++;
345         spin_unlock(&sbi->s_next_gen_lock);
346         insert_inode_hash(inode);
347
348         err = nilfs_init_acl(inode, dir);
349         if (unlikely(err))
350                 goto failed_acl; /* never occur. When supporting
351                                     nilfs_init_acl(), proper cancellation of
352                                     above jobs should be considered */
353
354         return inode;
355
356  failed_acl:
357  failed_bmap:
358         inode->i_nlink = 0;
359         iput(inode);  /* raw_inode will be deleted through
360                          generic_delete_inode() */
361         goto failed;
362
363  failed_ifile_create_inode:
364         make_bad_inode(inode);
365         iput(inode);  /* if i_nlink == 1, generic_forget_inode() will be
366                          called */
367  failed:
368         return ERR_PTR(err);
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 & FS_SYNC_FL)
378                 inode->i_flags |= S_SYNC;
379         if (flags & FS_APPEND_FL)
380                 inode->i_flags |= S_APPEND;
381         if (flags & FS_IMMUTABLE_FL)
382                 inode->i_flags |= S_IMMUTABLE;
383         if (flags & FS_NOATIME_FL)
384                 inode->i_flags |= S_NOATIME;
385         if (flags & FS_DIRSYNC_FL)
386                 inode->i_flags |= S_DIRSYNC;
387         mapping_set_gfp_mask(inode->i_mapping,
388                              mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
389 }
390
391 int nilfs_read_inode_common(struct inode *inode,
392                             struct nilfs_inode *raw_inode)
393 {
394         struct nilfs_inode_info *ii = NILFS_I(inode);
395         int err;
396
397         inode->i_mode = le16_to_cpu(raw_inode->i_mode);
398         inode->i_uid = (uid_t)le32_to_cpu(raw_inode->i_uid);
399         inode->i_gid = (gid_t)le32_to_cpu(raw_inode->i_gid);
400         inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
401         inode->i_size = le64_to_cpu(raw_inode->i_size);
402         inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
403         inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
404         inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
405         inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
406         inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
407         inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
408         if (inode->i_nlink == 0 && inode->i_mode == 0)
409                 return -EINVAL; /* this inode is deleted */
410
411         inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
412         ii->i_flags = le32_to_cpu(raw_inode->i_flags);
413 #if 0
414         ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
415         ii->i_dir_acl = S_ISREG(inode->i_mode) ?
416                 0 : le32_to_cpu(raw_inode->i_dir_acl);
417 #endif
418         ii->i_dir_start_lookup = 0;
419         inode->i_generation = le32_to_cpu(raw_inode->i_generation);
420
421         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
422             S_ISLNK(inode->i_mode)) {
423                 err = nilfs_bmap_read(ii->i_bmap, raw_inode);
424                 if (err < 0)
425                         return err;
426                 set_bit(NILFS_I_BMAP, &ii->i_state);
427                 /* No lock is needed; iget() ensures it. */
428         }
429         return 0;
430 }
431
432 static int __nilfs_read_inode(struct super_block *sb,
433                               struct nilfs_root *root, unsigned long ino,
434                               struct inode *inode)
435 {
436         struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs;
437         struct buffer_head *bh;
438         struct nilfs_inode *raw_inode;
439         int err;
440
441         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
442         err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
443         if (unlikely(err))
444                 goto bad_inode;
445
446         raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
447
448         err = nilfs_read_inode_common(inode, raw_inode);
449         if (err)
450                 goto failed_unmap;
451
452         if (S_ISREG(inode->i_mode)) {
453                 inode->i_op = &nilfs_file_inode_operations;
454                 inode->i_fop = &nilfs_file_operations;
455                 inode->i_mapping->a_ops = &nilfs_aops;
456         } else if (S_ISDIR(inode->i_mode)) {
457                 inode->i_op = &nilfs_dir_inode_operations;
458                 inode->i_fop = &nilfs_dir_operations;
459                 inode->i_mapping->a_ops = &nilfs_aops;
460         } else if (S_ISLNK(inode->i_mode)) {
461                 inode->i_op = &nilfs_symlink_inode_operations;
462                 inode->i_mapping->a_ops = &nilfs_aops;
463         } else {
464                 inode->i_op = &nilfs_special_inode_operations;
465                 init_special_inode(
466                         inode, inode->i_mode,
467                         huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
468         }
469         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
470         brelse(bh);
471         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
472         nilfs_set_inode_flags(inode);
473         return 0;
474
475  failed_unmap:
476         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
477         brelse(bh);
478
479  bad_inode:
480         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
481         return err;
482 }
483
484 static int nilfs_iget_test(struct inode *inode, void *opaque)
485 {
486         struct nilfs_iget_args *args = opaque;
487         struct nilfs_inode_info *ii;
488
489         if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
490                 return 0;
491
492         ii = NILFS_I(inode);
493         if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
494                 return !args->for_gc;
495
496         return args->for_gc && args->cno == ii->i_cno;
497 }
498
499 static int nilfs_iget_set(struct inode *inode, void *opaque)
500 {
501         struct nilfs_iget_args *args = opaque;
502
503         inode->i_ino = args->ino;
504         if (args->for_gc) {
505                 NILFS_I(inode)->i_state = 1 << NILFS_I_GCINODE;
506                 NILFS_I(inode)->i_cno = args->cno;
507                 NILFS_I(inode)->i_root = NULL;
508         } else {
509                 if (args->root && args->ino == NILFS_ROOT_INO)
510                         nilfs_get_root(args->root);
511                 NILFS_I(inode)->i_root = args->root;
512         }
513         return 0;
514 }
515
516 struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
517                             unsigned long ino)
518 {
519         struct nilfs_iget_args args = {
520                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
521         };
522
523         return ilookup5(sb, ino, nilfs_iget_test, &args);
524 }
525
526 struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
527                                 unsigned long ino)
528 {
529         struct nilfs_iget_args args = {
530                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
531         };
532
533         return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
534 }
535
536 struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
537                          unsigned long ino)
538 {
539         struct inode *inode;
540         int err;
541
542         inode = nilfs_iget_locked(sb, root, ino);
543         if (unlikely(!inode))
544                 return ERR_PTR(-ENOMEM);
545         if (!(inode->i_state & I_NEW))
546                 return inode;
547
548         err = __nilfs_read_inode(sb, root, ino, inode);
549         if (unlikely(err)) {
550                 iget_failed(inode);
551                 return ERR_PTR(err);
552         }
553         unlock_new_inode(inode);
554         return inode;
555 }
556
557 struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
558                                 __u64 cno)
559 {
560         struct nilfs_iget_args args = {
561                 .ino = ino, .root = NULL, .cno = cno, .for_gc = 1
562         };
563         struct inode *inode;
564         int err;
565
566         inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
567         if (unlikely(!inode))
568                 return ERR_PTR(-ENOMEM);
569         if (!(inode->i_state & I_NEW))
570                 return inode;
571
572         err = nilfs_init_gcinode(inode);
573         if (unlikely(err)) {
574                 iget_failed(inode);
575                 return ERR_PTR(err);
576         }
577         unlock_new_inode(inode);
578         return inode;
579 }
580
581 void nilfs_write_inode_common(struct inode *inode,
582                               struct nilfs_inode *raw_inode, int has_bmap)
583 {
584         struct nilfs_inode_info *ii = NILFS_I(inode);
585
586         raw_inode->i_mode = cpu_to_le16(inode->i_mode);
587         raw_inode->i_uid = cpu_to_le32(inode->i_uid);
588         raw_inode->i_gid = cpu_to_le32(inode->i_gid);
589         raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
590         raw_inode->i_size = cpu_to_le64(inode->i_size);
591         raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
592         raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
593         raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
594         raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
595         raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
596
597         raw_inode->i_flags = cpu_to_le32(ii->i_flags);
598         raw_inode->i_generation = cpu_to_le32(inode->i_generation);
599
600         if (has_bmap)
601                 nilfs_bmap_write(ii->i_bmap, raw_inode);
602         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
603                 raw_inode->i_device_code =
604                         cpu_to_le64(huge_encode_dev(inode->i_rdev));
605         /* When extending inode, nilfs->ns_inode_size should be checked
606            for substitutions of appended fields */
607 }
608
609 void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh)
610 {
611         ino_t ino = inode->i_ino;
612         struct nilfs_inode_info *ii = NILFS_I(inode);
613         struct inode *ifile = ii->i_root->ifile;
614         struct nilfs_inode *raw_inode;
615
616         raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
617
618         if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
619                 memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
620         set_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
621
622         nilfs_write_inode_common(inode, raw_inode, 0);
623                 /* XXX: call with has_bmap = 0 is a workaround to avoid
624                    deadlock of bmap. This delays update of i_bmap to just
625                    before writing */
626         nilfs_ifile_unmap_inode(ifile, ino, ibh);
627 }
628
629 #define NILFS_MAX_TRUNCATE_BLOCKS       16384  /* 64MB for 4KB block */
630
631 static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
632                                 unsigned long from)
633 {
634         unsigned long b;
635         int ret;
636
637         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
638                 return;
639 repeat:
640         ret = nilfs_bmap_last_key(ii->i_bmap, &b);
641         if (ret == -ENOENT)
642                 return;
643         else if (ret < 0)
644                 goto failed;
645
646         if (b < from)
647                 return;
648
649         b -= min_t(unsigned long, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
650         ret = nilfs_bmap_truncate(ii->i_bmap, b);
651         nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
652         if (!ret || (ret == -ENOMEM &&
653                      nilfs_bmap_truncate(ii->i_bmap, b) == 0))
654                 goto repeat;
655
656 failed:
657         nilfs_warning(ii->vfs_inode.i_sb, __func__,
658                       "failed to truncate bmap (ino=%lu, err=%d)",
659                       ii->vfs_inode.i_ino, ret);
660 }
661
662 void nilfs_truncate(struct inode *inode)
663 {
664         unsigned long blkoff;
665         unsigned int blocksize;
666         struct nilfs_transaction_info ti;
667         struct super_block *sb = inode->i_sb;
668         struct nilfs_inode_info *ii = NILFS_I(inode);
669
670         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
671                 return;
672         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
673                 return;
674
675         blocksize = sb->s_blocksize;
676         blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
677         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
678
679         block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
680
681         nilfs_truncate_bmap(ii, blkoff);
682
683         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
684         if (IS_SYNC(inode))
685                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
686
687         nilfs_mark_inode_dirty(inode);
688         nilfs_set_file_dirty(inode, 0);
689         nilfs_transaction_commit(sb);
690         /* May construct a logical segment and may fail in sync mode.
691            But truncate has no return value. */
692 }
693
694 static void nilfs_clear_inode(struct inode *inode)
695 {
696         struct nilfs_inode_info *ii = NILFS_I(inode);
697         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
698
699         /*
700          * Free resources allocated in nilfs_read_inode(), here.
701          */
702         BUG_ON(!list_empty(&ii->i_dirty));
703         brelse(ii->i_bh);
704         ii->i_bh = NULL;
705
706         if (mdi && mdi->mi_palloc_cache)
707                 nilfs_palloc_destroy_cache(inode);
708
709         if (test_bit(NILFS_I_BMAP, &ii->i_state))
710                 nilfs_bmap_clear(ii->i_bmap);
711
712         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
713
714         if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
715                 nilfs_put_root(ii->i_root);
716 }
717
718 void nilfs_evict_inode(struct inode *inode)
719 {
720         struct nilfs_transaction_info ti;
721         struct super_block *sb = inode->i_sb;
722         struct nilfs_inode_info *ii = NILFS_I(inode);
723         int ret;
724
725         if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
726                 if (inode->i_data.nrpages)
727                         truncate_inode_pages(&inode->i_data, 0);
728                 end_writeback(inode);
729                 nilfs_clear_inode(inode);
730                 return;
731         }
732         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
733
734         if (inode->i_data.nrpages)
735                 truncate_inode_pages(&inode->i_data, 0);
736
737         /* TODO: some of the following operations may fail.  */
738         nilfs_truncate_bmap(ii, 0);
739         nilfs_mark_inode_dirty(inode);
740         end_writeback(inode);
741
742         ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
743         if (!ret)
744                 atomic_dec(&ii->i_root->inodes_count);
745
746         nilfs_clear_inode(inode);
747
748         if (IS_SYNC(inode))
749                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
750         nilfs_transaction_commit(sb);
751         /* May construct a logical segment and may fail in sync mode.
752            But delete_inode has no return value. */
753 }
754
755 int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
756 {
757         struct nilfs_transaction_info ti;
758         struct inode *inode = dentry->d_inode;
759         struct super_block *sb = inode->i_sb;
760         int err;
761
762         err = inode_change_ok(inode, iattr);
763         if (err)
764                 return err;
765
766         err = nilfs_transaction_begin(sb, &ti, 0);
767         if (unlikely(err))
768                 return err;
769
770         if ((iattr->ia_valid & ATTR_SIZE) &&
771             iattr->ia_size != i_size_read(inode)) {
772                 err = vmtruncate(inode, iattr->ia_size);
773                 if (unlikely(err))
774                         goto out_err;
775         }
776
777         setattr_copy(inode, iattr);
778         mark_inode_dirty(inode);
779
780         if (iattr->ia_valid & ATTR_MODE) {
781                 err = nilfs_acl_chmod(inode);
782                 if (unlikely(err))
783                         goto out_err;
784         }
785
786         return nilfs_transaction_commit(sb);
787
788 out_err:
789         nilfs_transaction_abort(sb);
790         return err;
791 }
792
793 int nilfs_permission(struct inode *inode, int mask, unsigned int flags)
794 {
795         struct nilfs_root *root;
796
797         if (flags & IPERM_FLAG_RCU)
798                 return -ECHILD;
799
800         root = NILFS_I(inode)->i_root;
801         if ((mask & MAY_WRITE) && root &&
802             root->cno != NILFS_CPTREE_CURRENT_CNO)
803                 return -EROFS; /* snapshot is not writable */
804
805         return generic_permission(inode, mask, flags, NULL);
806 }
807
808 int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
809 {
810         struct nilfs_sb_info *sbi = NILFS_SB(inode->i_sb);
811         struct nilfs_inode_info *ii = NILFS_I(inode);
812         int err;
813
814         spin_lock(&sbi->s_inode_lock);
815         if (ii->i_bh == NULL) {
816                 spin_unlock(&sbi->s_inode_lock);
817                 err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
818                                                   inode->i_ino, pbh);
819                 if (unlikely(err))
820                         return err;
821                 spin_lock(&sbi->s_inode_lock);
822                 if (ii->i_bh == NULL)
823                         ii->i_bh = *pbh;
824                 else {
825                         brelse(*pbh);
826                         *pbh = ii->i_bh;
827                 }
828         } else
829                 *pbh = ii->i_bh;
830
831         get_bh(*pbh);
832         spin_unlock(&sbi->s_inode_lock);
833         return 0;
834 }
835
836 int nilfs_inode_dirty(struct inode *inode)
837 {
838         struct nilfs_inode_info *ii = NILFS_I(inode);
839         struct nilfs_sb_info *sbi = NILFS_SB(inode->i_sb);
840         int ret = 0;
841
842         if (!list_empty(&ii->i_dirty)) {
843                 spin_lock(&sbi->s_inode_lock);
844                 ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
845                         test_bit(NILFS_I_BUSY, &ii->i_state);
846                 spin_unlock(&sbi->s_inode_lock);
847         }
848         return ret;
849 }
850
851 int nilfs_set_file_dirty(struct inode *inode, unsigned nr_dirty)
852 {
853         struct nilfs_sb_info *sbi = NILFS_SB(inode->i_sb);
854         struct nilfs_inode_info *ii = NILFS_I(inode);
855
856         atomic_add(nr_dirty, &sbi->s_nilfs->ns_ndirtyblks);
857
858         if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
859                 return 0;
860
861         spin_lock(&sbi->s_inode_lock);
862         if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
863             !test_bit(NILFS_I_BUSY, &ii->i_state)) {
864                 /* Because this routine may race with nilfs_dispose_list(),
865                    we have to check NILFS_I_QUEUED here, too. */
866                 if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
867                         /* This will happen when somebody is freeing
868                            this inode. */
869                         nilfs_warning(sbi->s_super, __func__,
870                                       "cannot get inode (ino=%lu)\n",
871                                       inode->i_ino);
872                         spin_unlock(&sbi->s_inode_lock);
873                         return -EINVAL; /* NILFS_I_DIRTY may remain for
874                                            freeing inode */
875                 }
876                 list_del(&ii->i_dirty);
877                 list_add_tail(&ii->i_dirty, &sbi->s_dirty_files);
878                 set_bit(NILFS_I_QUEUED, &ii->i_state);
879         }
880         spin_unlock(&sbi->s_inode_lock);
881         return 0;
882 }
883
884 int nilfs_mark_inode_dirty(struct inode *inode)
885 {
886         struct buffer_head *ibh;
887         int err;
888
889         err = nilfs_load_inode_block(inode, &ibh);
890         if (unlikely(err)) {
891                 nilfs_warning(inode->i_sb, __func__,
892                               "failed to reget inode block.\n");
893                 return err;
894         }
895         nilfs_update_inode(inode, ibh);
896         nilfs_mdt_mark_buffer_dirty(ibh);
897         nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
898         brelse(ibh);
899         return 0;
900 }
901
902 /**
903  * nilfs_dirty_inode - reflect changes on given inode to an inode block.
904  * @inode: inode of the file to be registered.
905  *
906  * nilfs_dirty_inode() loads a inode block containing the specified
907  * @inode and copies data from a nilfs_inode to a corresponding inode
908  * entry in the inode block. This operation is excluded from the segment
909  * construction. This function can be called both as a single operation
910  * and as a part of indivisible file operations.
911  */
912 void nilfs_dirty_inode(struct inode *inode)
913 {
914         struct nilfs_transaction_info ti;
915         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
916
917         if (is_bad_inode(inode)) {
918                 nilfs_warning(inode->i_sb, __func__,
919                               "tried to mark bad_inode dirty. ignored.\n");
920                 dump_stack();
921                 return;
922         }
923         if (mdi) {
924                 nilfs_mdt_mark_dirty(inode);
925                 return;
926         }
927         nilfs_transaction_begin(inode->i_sb, &ti, 0);
928         nilfs_mark_inode_dirty(inode);
929         nilfs_transaction_commit(inode->i_sb); /* never fails */
930 }
931
932 int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
933                  __u64 start, __u64 len)
934 {
935         struct the_nilfs *nilfs = NILFS_I_NILFS(inode);
936         __u64 logical = 0, phys = 0, size = 0;
937         __u32 flags = 0;
938         loff_t isize;
939         sector_t blkoff, end_blkoff;
940         sector_t delalloc_blkoff;
941         unsigned long delalloc_blklen;
942         unsigned int blkbits = inode->i_blkbits;
943         int ret, n;
944
945         ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
946         if (ret)
947                 return ret;
948
949         mutex_lock(&inode->i_mutex);
950
951         isize = i_size_read(inode);
952
953         blkoff = start >> blkbits;
954         end_blkoff = (start + len - 1) >> blkbits;
955
956         delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
957                                                         &delalloc_blkoff);
958
959         do {
960                 __u64 blkphy;
961                 unsigned int maxblocks;
962
963                 if (delalloc_blklen && blkoff == delalloc_blkoff) {
964                         if (size) {
965                                 /* End of the current extent */
966                                 ret = fiemap_fill_next_extent(
967                                         fieinfo, logical, phys, size, flags);
968                                 if (ret)
969                                         break;
970                         }
971                         if (blkoff > end_blkoff)
972                                 break;
973
974                         flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
975                         logical = blkoff << blkbits;
976                         phys = 0;
977                         size = delalloc_blklen << blkbits;
978
979                         blkoff = delalloc_blkoff + delalloc_blklen;
980                         delalloc_blklen = nilfs_find_uncommitted_extent(
981                                 inode, blkoff, &delalloc_blkoff);
982                         continue;
983                 }
984
985                 /*
986                  * Limit the number of blocks that we look up so as
987                  * not to get into the next delayed allocation extent.
988                  */
989                 maxblocks = INT_MAX;
990                 if (delalloc_blklen)
991                         maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
992                                           maxblocks);
993                 blkphy = 0;
994
995                 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
996                 n = nilfs_bmap_lookup_contig(
997                         NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
998                 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
999
1000                 if (n < 0) {
1001                         int past_eof;
1002
1003                         if (unlikely(n != -ENOENT))
1004                                 break; /* error */
1005
1006                         /* HOLE */
1007                         blkoff++;
1008                         past_eof = ((blkoff << blkbits) >= isize);
1009
1010                         if (size) {
1011                                 /* End of the current extent */
1012
1013                                 if (past_eof)
1014                                         flags |= FIEMAP_EXTENT_LAST;
1015
1016                                 ret = fiemap_fill_next_extent(
1017                                         fieinfo, logical, phys, size, flags);
1018                                 if (ret)
1019                                         break;
1020                                 size = 0;
1021                         }
1022                         if (blkoff > end_blkoff || past_eof)
1023                                 break;
1024                 } else {
1025                         if (size) {
1026                                 if (phys && blkphy << blkbits == phys + size) {
1027                                         /* The current extent goes on */
1028                                         size += n << blkbits;
1029                                 } else {
1030                                         /* Terminate the current extent */
1031                                         ret = fiemap_fill_next_extent(
1032                                                 fieinfo, logical, phys, size,
1033                                                 flags);
1034                                         if (ret || blkoff > end_blkoff)
1035                                                 break;
1036
1037                                         /* Start another extent */
1038                                         flags = FIEMAP_EXTENT_MERGED;
1039                                         logical = blkoff << blkbits;
1040                                         phys = blkphy << blkbits;
1041                                         size = n << blkbits;
1042                                 }
1043                         } else {
1044                                 /* Start a new extent */
1045                                 flags = FIEMAP_EXTENT_MERGED;
1046                                 logical = blkoff << blkbits;
1047                                 phys = blkphy << blkbits;
1048                                 size = n << blkbits;
1049                         }
1050                         blkoff += n;
1051                 }
1052                 cond_resched();
1053         } while (true);
1054
1055         /* If ret is 1 then we just hit the end of the extent array */
1056         if (ret == 1)
1057                 ret = 0;
1058
1059         mutex_unlock(&inode->i_mutex);
1060         return ret;
1061 }