1 /*
2 * linux/fs/hfs/inode.c
3 *
4 * Copyright (C) 1995-1997 Paul H. Hargrove
5 * (C) 2003 Ardis Technologies <roman@ardistech.com>
6 * This file may be distributed under the terms of the GNU General Public License.
7 *
8 * This file contains inode-related functions which do not depend on
9 * which scheme is being used to represent forks.
10 *
11 * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
12 */
13
14 #include <linux/pagemap.h>
15 #include <linux/mpage.h>
16 #include <linux/sched.h>
17 #include <linux/cred.h>
18 #include <linux/uio.h>
19 #include <linux/xattr.h>
20
21 #include "hfs_fs.h"
22 #include "btree.h"
23
24 static const struct file_operations hfs_file_operations;
25 static const struct inode_operations hfs_file_inode_operations;
26
27 /*================ Variable-like macros ================*/
28
29 #define HFS_VALID_MODE_BITS (S_IFREG | S_IFDIR | S_IRWXUGO)
30
hfs_writepage(struct page * page,struct writeback_control * wbc)31 static int hfs_writepage(struct page *page, struct writeback_control *wbc)
32 {
33 return block_write_full_page(page, hfs_get_block, wbc);
34 }
35
hfs_readpage(struct file * file,struct page * page)36 static int hfs_readpage(struct file *file, struct page *page)
37 {
38 return block_read_full_page(page, hfs_get_block);
39 }
40
hfs_write_failed(struct address_space * mapping,loff_t to)41 static void hfs_write_failed(struct address_space *mapping, loff_t to)
42 {
43 struct inode *inode = mapping->host;
44
45 if (to > inode->i_size) {
46 truncate_pagecache(inode, inode->i_size);
47 hfs_file_truncate(inode);
48 }
49 }
50
hfs_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)51 static int hfs_write_begin(struct file *file, struct address_space *mapping,
52 loff_t pos, unsigned len, unsigned flags,
53 struct page **pagep, void **fsdata)
54 {
55 int ret;
56
57 *pagep = NULL;
58 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
59 hfs_get_block,
60 &HFS_I(mapping->host)->phys_size);
61 if (unlikely(ret))
62 hfs_write_failed(mapping, pos + len);
63
64 return ret;
65 }
66
hfs_bmap(struct address_space * mapping,sector_t block)67 static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
68 {
69 return generic_block_bmap(mapping, block, hfs_get_block);
70 }
71
hfs_releasepage(struct page * page,gfp_t mask)72 static int hfs_releasepage(struct page *page, gfp_t mask)
73 {
74 struct inode *inode = page->mapping->host;
75 struct super_block *sb = inode->i_sb;
76 struct hfs_btree *tree;
77 struct hfs_bnode *node;
78 u32 nidx;
79 int i, res = 1;
80
81 switch (inode->i_ino) {
82 case HFS_EXT_CNID:
83 tree = HFS_SB(sb)->ext_tree;
84 break;
85 case HFS_CAT_CNID:
86 tree = HFS_SB(sb)->cat_tree;
87 break;
88 default:
89 BUG();
90 return 0;
91 }
92
93 if (!tree)
94 return 0;
95
96 if (tree->node_size >= PAGE_SIZE) {
97 nidx = page->index >> (tree->node_size_shift - PAGE_SHIFT);
98 spin_lock(&tree->hash_lock);
99 node = hfs_bnode_findhash(tree, nidx);
100 if (!node)
101 ;
102 else if (atomic_read(&node->refcnt))
103 res = 0;
104 if (res && node) {
105 hfs_bnode_unhash(node);
106 hfs_bnode_free(node);
107 }
108 spin_unlock(&tree->hash_lock);
109 } else {
110 nidx = page->index << (PAGE_SHIFT - tree->node_size_shift);
111 i = 1 << (PAGE_SHIFT - tree->node_size_shift);
112 spin_lock(&tree->hash_lock);
113 do {
114 node = hfs_bnode_findhash(tree, nidx++);
115 if (!node)
116 continue;
117 if (atomic_read(&node->refcnt)) {
118 res = 0;
119 break;
120 }
121 hfs_bnode_unhash(node);
122 hfs_bnode_free(node);
123 } while (--i && nidx < tree->node_count);
124 spin_unlock(&tree->hash_lock);
125 }
126 return res ? try_to_free_buffers(page) : 0;
127 }
128
hfs_direct_IO(struct kiocb * iocb,struct iov_iter * iter)129 static ssize_t hfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
130 {
131 struct file *file = iocb->ki_filp;
132 struct address_space *mapping = file->f_mapping;
133 struct inode *inode = mapping->host;
134 size_t count = iov_iter_count(iter);
135 ssize_t ret;
136
137 ret = blockdev_direct_IO(iocb, inode, iter, hfs_get_block);
138
139 /*
140 * In case of error extending write may have instantiated a few
141 * blocks outside i_size. Trim these off again.
142 */
143 if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
144 loff_t isize = i_size_read(inode);
145 loff_t end = iocb->ki_pos + count;
146
147 if (end > isize)
148 hfs_write_failed(mapping, end);
149 }
150
151 return ret;
152 }
153
hfs_writepages(struct address_space * mapping,struct writeback_control * wbc)154 static int hfs_writepages(struct address_space *mapping,
155 struct writeback_control *wbc)
156 {
157 return mpage_writepages(mapping, wbc, hfs_get_block);
158 }
159
160 const struct address_space_operations hfs_btree_aops = {
161 .readpage = hfs_readpage,
162 .writepage = hfs_writepage,
163 .write_begin = hfs_write_begin,
164 .write_end = generic_write_end,
165 .bmap = hfs_bmap,
166 .releasepage = hfs_releasepage,
167 };
168
169 const struct address_space_operations hfs_aops = {
170 .readpage = hfs_readpage,
171 .writepage = hfs_writepage,
172 .write_begin = hfs_write_begin,
173 .write_end = generic_write_end,
174 .bmap = hfs_bmap,
175 .direct_IO = hfs_direct_IO,
176 .writepages = hfs_writepages,
177 };
178
179 /*
180 * hfs_new_inode
181 */
hfs_new_inode(struct inode * dir,const struct qstr * name,umode_t mode)182 struct inode *hfs_new_inode(struct inode *dir, const struct qstr *name, umode_t mode)
183 {
184 struct super_block *sb = dir->i_sb;
185 struct inode *inode = new_inode(sb);
186 if (!inode)
187 return NULL;
188
189 mutex_init(&HFS_I(inode)->extents_lock);
190 INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
191 spin_lock_init(&HFS_I(inode)->open_dir_lock);
192 hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, name);
193 inode->i_ino = HFS_SB(sb)->next_id++;
194 inode->i_mode = mode;
195 inode->i_uid = current_fsuid();
196 inode->i_gid = current_fsgid();
197 set_nlink(inode, 1);
198 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
199 HFS_I(inode)->flags = 0;
200 HFS_I(inode)->rsrc_inode = NULL;
201 HFS_I(inode)->fs_blocks = 0;
202 if (S_ISDIR(mode)) {
203 inode->i_size = 2;
204 HFS_SB(sb)->folder_count++;
205 if (dir->i_ino == HFS_ROOT_CNID)
206 HFS_SB(sb)->root_dirs++;
207 inode->i_op = &hfs_dir_inode_operations;
208 inode->i_fop = &hfs_dir_operations;
209 inode->i_mode |= S_IRWXUGO;
210 inode->i_mode &= ~HFS_SB(inode->i_sb)->s_dir_umask;
211 } else if (S_ISREG(mode)) {
212 HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
213 HFS_SB(sb)->file_count++;
214 if (dir->i_ino == HFS_ROOT_CNID)
215 HFS_SB(sb)->root_files++;
216 inode->i_op = &hfs_file_inode_operations;
217 inode->i_fop = &hfs_file_operations;
218 inode->i_mapping->a_ops = &hfs_aops;
219 inode->i_mode |= S_IRUGO|S_IXUGO;
220 if (mode & S_IWUSR)
221 inode->i_mode |= S_IWUGO;
222 inode->i_mode &= ~HFS_SB(inode->i_sb)->s_file_umask;
223 HFS_I(inode)->phys_size = 0;
224 HFS_I(inode)->alloc_blocks = 0;
225 HFS_I(inode)->first_blocks = 0;
226 HFS_I(inode)->cached_start = 0;
227 HFS_I(inode)->cached_blocks = 0;
228 memset(HFS_I(inode)->first_extents, 0, sizeof(hfs_extent_rec));
229 memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
230 }
231 insert_inode_hash(inode);
232 mark_inode_dirty(inode);
233 set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
234 hfs_mark_mdb_dirty(sb);
235
236 return inode;
237 }
238
hfs_delete_inode(struct inode * inode)239 void hfs_delete_inode(struct inode *inode)
240 {
241 struct super_block *sb = inode->i_sb;
242
243 hfs_dbg(INODE, "delete_inode: %lu\n", inode->i_ino);
244 if (S_ISDIR(inode->i_mode)) {
245 HFS_SB(sb)->folder_count--;
246 if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
247 HFS_SB(sb)->root_dirs--;
248 set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
249 hfs_mark_mdb_dirty(sb);
250 return;
251 }
252 HFS_SB(sb)->file_count--;
253 if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
254 HFS_SB(sb)->root_files--;
255 if (S_ISREG(inode->i_mode)) {
256 if (!inode->i_nlink) {
257 inode->i_size = 0;
258 hfs_file_truncate(inode);
259 }
260 }
261 set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
262 hfs_mark_mdb_dirty(sb);
263 }
264
hfs_inode_read_fork(struct inode * inode,struct hfs_extent * ext,__be32 __log_size,__be32 phys_size,u32 clump_size)265 void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
266 __be32 __log_size, __be32 phys_size, u32 clump_size)
267 {
268 struct super_block *sb = inode->i_sb;
269 u32 log_size = be32_to_cpu(__log_size);
270 u16 count;
271 int i;
272
273 memcpy(HFS_I(inode)->first_extents, ext, sizeof(hfs_extent_rec));
274 for (count = 0, i = 0; i < 3; i++)
275 count += be16_to_cpu(ext[i].count);
276 HFS_I(inode)->first_blocks = count;
277
278 inode->i_size = HFS_I(inode)->phys_size = log_size;
279 HFS_I(inode)->fs_blocks = (log_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
280 inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
281 HFS_I(inode)->alloc_blocks = be32_to_cpu(phys_size) /
282 HFS_SB(sb)->alloc_blksz;
283 HFS_I(inode)->clump_blocks = clump_size / HFS_SB(sb)->alloc_blksz;
284 if (!HFS_I(inode)->clump_blocks)
285 HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
286 }
287
288 struct hfs_iget_data {
289 struct hfs_cat_key *key;
290 hfs_cat_rec *rec;
291 };
292
hfs_test_inode(struct inode * inode,void * data)293 static int hfs_test_inode(struct inode *inode, void *data)
294 {
295 struct hfs_iget_data *idata = data;
296 hfs_cat_rec *rec;
297
298 rec = idata->rec;
299 switch (rec->type) {
300 case HFS_CDR_DIR:
301 return inode->i_ino == be32_to_cpu(rec->dir.DirID);
302 case HFS_CDR_FIL:
303 return inode->i_ino == be32_to_cpu(rec->file.FlNum);
304 default:
305 BUG();
306 return 1;
307 }
308 }
309
310 /*
311 * hfs_read_inode
312 */
hfs_read_inode(struct inode * inode,void * data)313 static int hfs_read_inode(struct inode *inode, void *data)
314 {
315 struct hfs_iget_data *idata = data;
316 struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
317 hfs_cat_rec *rec;
318
319 HFS_I(inode)->flags = 0;
320 HFS_I(inode)->rsrc_inode = NULL;
321 mutex_init(&HFS_I(inode)->extents_lock);
322 INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
323 spin_lock_init(&HFS_I(inode)->open_dir_lock);
324
325 /* Initialize the inode */
326 inode->i_uid = hsb->s_uid;
327 inode->i_gid = hsb->s_gid;
328 set_nlink(inode, 1);
329
330 if (idata->key)
331 HFS_I(inode)->cat_key = *idata->key;
332 else
333 HFS_I(inode)->flags |= HFS_FLG_RSRC;
334 HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
335
336 rec = idata->rec;
337 switch (rec->type) {
338 case HFS_CDR_FIL:
339 if (!HFS_IS_RSRC(inode)) {
340 hfs_inode_read_fork(inode, rec->file.ExtRec, rec->file.LgLen,
341 rec->file.PyLen, be16_to_cpu(rec->file.ClpSize));
342 } else {
343 hfs_inode_read_fork(inode, rec->file.RExtRec, rec->file.RLgLen,
344 rec->file.RPyLen, be16_to_cpu(rec->file.ClpSize));
345 }
346
347 inode->i_ino = be32_to_cpu(rec->file.FlNum);
348 inode->i_mode = S_IRUGO | S_IXUGO;
349 if (!(rec->file.Flags & HFS_FIL_LOCK))
350 inode->i_mode |= S_IWUGO;
351 inode->i_mode &= ~hsb->s_file_umask;
352 inode->i_mode |= S_IFREG;
353 inode->i_ctime = inode->i_atime = inode->i_mtime =
354 timespec_to_timespec64(hfs_m_to_utime(rec->file.MdDat));
355 inode->i_op = &hfs_file_inode_operations;
356 inode->i_fop = &hfs_file_operations;
357 inode->i_mapping->a_ops = &hfs_aops;
358 break;
359 case HFS_CDR_DIR:
360 inode->i_ino = be32_to_cpu(rec->dir.DirID);
361 inode->i_size = be16_to_cpu(rec->dir.Val) + 2;
362 HFS_I(inode)->fs_blocks = 0;
363 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~hsb->s_dir_umask);
364 inode->i_ctime = inode->i_atime = inode->i_mtime =
365 timespec_to_timespec64(hfs_m_to_utime(rec->dir.MdDat));
366 inode->i_op = &hfs_dir_inode_operations;
367 inode->i_fop = &hfs_dir_operations;
368 break;
369 default:
370 make_bad_inode(inode);
371 }
372 return 0;
373 }
374
375 /*
376 * __hfs_iget()
377 *
378 * Given the MDB for a HFS filesystem, a 'key' and an 'entry' in
379 * the catalog B-tree and the 'type' of the desired file return the
380 * inode for that file/directory or NULL. Note that 'type' indicates
381 * whether we want the actual file or directory, or the corresponding
382 * metadata (AppleDouble header file or CAP metadata file).
383 */
hfs_iget(struct super_block * sb,struct hfs_cat_key * key,hfs_cat_rec * rec)384 struct inode *hfs_iget(struct super_block *sb, struct hfs_cat_key *key, hfs_cat_rec *rec)
385 {
386 struct hfs_iget_data data = { key, rec };
387 struct inode *inode;
388 u32 cnid;
389
390 switch (rec->type) {
391 case HFS_CDR_DIR:
392 cnid = be32_to_cpu(rec->dir.DirID);
393 break;
394 case HFS_CDR_FIL:
395 cnid = be32_to_cpu(rec->file.FlNum);
396 break;
397 default:
398 return NULL;
399 }
400 inode = iget5_locked(sb, cnid, hfs_test_inode, hfs_read_inode, &data);
401 if (inode && (inode->i_state & I_NEW))
402 unlock_new_inode(inode);
403 return inode;
404 }
405
hfs_inode_write_fork(struct inode * inode,struct hfs_extent * ext,__be32 * log_size,__be32 * phys_size)406 void hfs_inode_write_fork(struct inode *inode, struct hfs_extent *ext,
407 __be32 *log_size, __be32 *phys_size)
408 {
409 memcpy(ext, HFS_I(inode)->first_extents, sizeof(hfs_extent_rec));
410
411 if (log_size)
412 *log_size = cpu_to_be32(inode->i_size);
413 if (phys_size)
414 *phys_size = cpu_to_be32(HFS_I(inode)->alloc_blocks *
415 HFS_SB(inode->i_sb)->alloc_blksz);
416 }
417
hfs_write_inode(struct inode * inode,struct writeback_control * wbc)418 int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
419 {
420 struct inode *main_inode = inode;
421 struct hfs_find_data fd;
422 hfs_cat_rec rec;
423 int res;
424
425 hfs_dbg(INODE, "hfs_write_inode: %lu\n", inode->i_ino);
426 res = hfs_ext_write_extent(inode);
427 if (res)
428 return res;
429
430 if (inode->i_ino < HFS_FIRSTUSER_CNID) {
431 switch (inode->i_ino) {
432 case HFS_ROOT_CNID:
433 break;
434 case HFS_EXT_CNID:
435 hfs_btree_write(HFS_SB(inode->i_sb)->ext_tree);
436 return 0;
437 case HFS_CAT_CNID:
438 hfs_btree_write(HFS_SB(inode->i_sb)->cat_tree);
439 return 0;
440 default:
441 BUG();
442 return -EIO;
443 }
444 }
445
446 if (HFS_IS_RSRC(inode))
447 main_inode = HFS_I(inode)->rsrc_inode;
448
449 if (!main_inode->i_nlink)
450 return 0;
451
452 if (hfs_find_init(HFS_SB(main_inode->i_sb)->cat_tree, &fd))
453 /* panic? */
454 return -EIO;
455
456 fd.search_key->cat = HFS_I(main_inode)->cat_key;
457 if (hfs_brec_find(&fd))
458 /* panic? */
459 goto out;
460
461 if (S_ISDIR(main_inode->i_mode)) {
462 if (fd.entrylength < sizeof(struct hfs_cat_dir))
463 /* panic? */;
464 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
465 sizeof(struct hfs_cat_dir));
466 if (rec.type != HFS_CDR_DIR ||
467 be32_to_cpu(rec.dir.DirID) != inode->i_ino) {
468 }
469
470 rec.dir.MdDat = hfs_u_to_mtime(inode->i_mtime);
471 rec.dir.Val = cpu_to_be16(inode->i_size - 2);
472
473 hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
474 sizeof(struct hfs_cat_dir));
475 } else if (HFS_IS_RSRC(inode)) {
476 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
477 sizeof(struct hfs_cat_file));
478 hfs_inode_write_fork(inode, rec.file.RExtRec,
479 &rec.file.RLgLen, &rec.file.RPyLen);
480 hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
481 sizeof(struct hfs_cat_file));
482 } else {
483 if (fd.entrylength < sizeof(struct hfs_cat_file))
484 /* panic? */;
485 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
486 sizeof(struct hfs_cat_file));
487 if (rec.type != HFS_CDR_FIL ||
488 be32_to_cpu(rec.file.FlNum) != inode->i_ino) {
489 }
490
491 if (inode->i_mode & S_IWUSR)
492 rec.file.Flags &= ~HFS_FIL_LOCK;
493 else
494 rec.file.Flags |= HFS_FIL_LOCK;
495 hfs_inode_write_fork(inode, rec.file.ExtRec, &rec.file.LgLen, &rec.file.PyLen);
496 rec.file.MdDat = hfs_u_to_mtime(inode->i_mtime);
497
498 hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
499 sizeof(struct hfs_cat_file));
500 }
501 out:
502 hfs_find_exit(&fd);
503 return 0;
504 }
505
hfs_file_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)506 static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
507 unsigned int flags)
508 {
509 struct inode *inode = NULL;
510 hfs_cat_rec rec;
511 struct hfs_find_data fd;
512 int res;
513
514 if (HFS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc"))
515 goto out;
516
517 inode = HFS_I(dir)->rsrc_inode;
518 if (inode)
519 goto out;
520
521 inode = new_inode(dir->i_sb);
522 if (!inode)
523 return ERR_PTR(-ENOMEM);
524
525 res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
526 if (res) {
527 iput(inode);
528 return ERR_PTR(res);
529 }
530 fd.search_key->cat = HFS_I(dir)->cat_key;
531 res = hfs_brec_read(&fd, &rec, sizeof(rec));
532 if (!res) {
533 struct hfs_iget_data idata = { NULL, &rec };
534 hfs_read_inode(inode, &idata);
535 }
536 hfs_find_exit(&fd);
537 if (res) {
538 iput(inode);
539 return ERR_PTR(res);
540 }
541 HFS_I(inode)->rsrc_inode = dir;
542 HFS_I(dir)->rsrc_inode = inode;
543 igrab(dir);
544 inode_fake_hash(inode);
545 mark_inode_dirty(inode);
546 dont_mount(dentry);
547 out:
548 return d_splice_alias(inode, dentry);
549 }
550
hfs_evict_inode(struct inode * inode)551 void hfs_evict_inode(struct inode *inode)
552 {
553 truncate_inode_pages_final(&inode->i_data);
554 clear_inode(inode);
555 if (HFS_IS_RSRC(inode) && HFS_I(inode)->rsrc_inode) {
556 HFS_I(HFS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
557 iput(HFS_I(inode)->rsrc_inode);
558 }
559 }
560
hfs_file_open(struct inode * inode,struct file * file)561 static int hfs_file_open(struct inode *inode, struct file *file)
562 {
563 if (HFS_IS_RSRC(inode))
564 inode = HFS_I(inode)->rsrc_inode;
565 atomic_inc(&HFS_I(inode)->opencnt);
566 return 0;
567 }
568
hfs_file_release(struct inode * inode,struct file * file)569 static int hfs_file_release(struct inode *inode, struct file *file)
570 {
571 //struct super_block *sb = inode->i_sb;
572
573 if (HFS_IS_RSRC(inode))
574 inode = HFS_I(inode)->rsrc_inode;
575 if (atomic_dec_and_test(&HFS_I(inode)->opencnt)) {
576 inode_lock(inode);
577 hfs_file_truncate(inode);
578 //if (inode->i_flags & S_DEAD) {
579 // hfs_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
580 // hfs_delete_inode(inode);
581 //}
582 inode_unlock(inode);
583 }
584 return 0;
585 }
586
587 /*
588 * hfs_notify_change()
589 *
590 * Based very closely on fs/msdos/inode.c by Werner Almesberger
591 *
592 * This is the notify_change() field in the super_operations structure
593 * for HFS file systems. The purpose is to take that changes made to
594 * an inode and apply then in a filesystem-dependent manner. In this
595 * case the process has a few of tasks to do:
596 * 1) prevent changes to the i_uid and i_gid fields.
597 * 2) map file permissions to the closest allowable permissions
598 * 3) Since multiple Linux files can share the same on-disk inode under
599 * HFS (for instance the data and resource forks of a file) a change
600 * to permissions must be applied to all other in-core inodes which
601 * correspond to the same HFS file.
602 */
603
hfs_inode_setattr(struct dentry * dentry,struct iattr * attr)604 int hfs_inode_setattr(struct dentry *dentry, struct iattr * attr)
605 {
606 struct inode *inode = d_inode(dentry);
607 struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
608 int error;
609
610 error = setattr_prepare(dentry, attr); /* basic permission checks */
611 if (error)
612 return error;
613
614 /* no uig/gid changes and limit which mode bits can be set */
615 if (((attr->ia_valid & ATTR_UID) &&
616 (!uid_eq(attr->ia_uid, hsb->s_uid))) ||
617 ((attr->ia_valid & ATTR_GID) &&
618 (!gid_eq(attr->ia_gid, hsb->s_gid))) ||
619 ((attr->ia_valid & ATTR_MODE) &&
620 ((S_ISDIR(inode->i_mode) &&
621 (attr->ia_mode != inode->i_mode)) ||
622 (attr->ia_mode & ~HFS_VALID_MODE_BITS)))) {
623 return hsb->s_quiet ? 0 : error;
624 }
625
626 if (attr->ia_valid & ATTR_MODE) {
627 /* Only the 'w' bits can ever change and only all together. */
628 if (attr->ia_mode & S_IWUSR)
629 attr->ia_mode = inode->i_mode | S_IWUGO;
630 else
631 attr->ia_mode = inode->i_mode & ~S_IWUGO;
632 attr->ia_mode &= S_ISDIR(inode->i_mode) ? ~hsb->s_dir_umask: ~hsb->s_file_umask;
633 }
634
635 if ((attr->ia_valid & ATTR_SIZE) &&
636 attr->ia_size != i_size_read(inode)) {
637 inode_dio_wait(inode);
638
639 error = inode_newsize_ok(inode, attr->ia_size);
640 if (error)
641 return error;
642
643 truncate_setsize(inode, attr->ia_size);
644 hfs_file_truncate(inode);
645 inode->i_atime = inode->i_mtime = inode->i_ctime =
646 current_time(inode);
647 }
648
649 setattr_copy(inode, attr);
650 mark_inode_dirty(inode);
651 return 0;
652 }
653
hfs_file_fsync(struct file * filp,loff_t start,loff_t end,int datasync)654 static int hfs_file_fsync(struct file *filp, loff_t start, loff_t end,
655 int datasync)
656 {
657 struct inode *inode = filp->f_mapping->host;
658 struct super_block * sb;
659 int ret, err;
660
661 ret = file_write_and_wait_range(filp, start, end);
662 if (ret)
663 return ret;
664 inode_lock(inode);
665
666 /* sync the inode to buffers */
667 ret = write_inode_now(inode, 0);
668
669 /* sync the superblock to buffers */
670 sb = inode->i_sb;
671 flush_delayed_work(&HFS_SB(sb)->mdb_work);
672 /* .. finally sync the buffers to disk */
673 err = sync_blockdev(sb->s_bdev);
674 if (!ret)
675 ret = err;
676 inode_unlock(inode);
677 return ret;
678 }
679
680 static const struct file_operations hfs_file_operations = {
681 .llseek = generic_file_llseek,
682 .read_iter = generic_file_read_iter,
683 .write_iter = generic_file_write_iter,
684 .mmap = generic_file_mmap,
685 .splice_read = generic_file_splice_read,
686 .fsync = hfs_file_fsync,
687 .open = hfs_file_open,
688 .release = hfs_file_release,
689 };
690
691 static const struct inode_operations hfs_file_inode_operations = {
692 .lookup = hfs_file_lookup,
693 .setattr = hfs_inode_setattr,
694 .listxattr = generic_listxattr,
695 };
696