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 #include <linux/blkdev.h>
21
22 #include "hfs_fs.h"
23 #include "btree.h"
24
25 static const struct file_operations hfs_file_operations;
26 static const struct inode_operations hfs_file_inode_operations;
27
28 /*================ Variable-like macros ================*/
29
30 #define HFS_VALID_MODE_BITS (S_IFREG | S_IFDIR | S_IRWXUGO)
31
hfs_writepage(struct page * page,struct writeback_control * wbc)32 static int hfs_writepage(struct page *page, struct writeback_control *wbc)
33 {
34 return block_write_full_page(page, hfs_get_block, wbc);
35 }
36
hfs_readpage(struct file * file,struct page * page)37 static int hfs_readpage(struct file *file, struct page *page)
38 {
39 return block_read_full_page(page, hfs_get_block);
40 }
41
hfs_write_failed(struct address_space * mapping,loff_t to)42 static void hfs_write_failed(struct address_space *mapping, loff_t to)
43 {
44 struct inode *inode = mapping->host;
45
46 if (to > inode->i_size) {
47 truncate_pagecache(inode, inode->i_size);
48 hfs_file_truncate(inode);
49 }
50 }
51
hfs_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)52 static int hfs_write_begin(struct file *file, struct address_space *mapping,
53 loff_t pos, unsigned len, unsigned flags,
54 struct page **pagep, void **fsdata)
55 {
56 int ret;
57
58 *pagep = NULL;
59 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
60 hfs_get_block,
61 &HFS_I(mapping->host)->phys_size);
62 if (unlikely(ret))
63 hfs_write_failed(mapping, pos + len);
64
65 return ret;
66 }
67
hfs_bmap(struct address_space * mapping,sector_t block)68 static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
69 {
70 return generic_block_bmap(mapping, block, hfs_get_block);
71 }
72
hfs_releasepage(struct page * page,gfp_t mask)73 static int hfs_releasepage(struct page *page, gfp_t mask)
74 {
75 struct inode *inode = page->mapping->host;
76 struct super_block *sb = inode->i_sb;
77 struct hfs_btree *tree;
78 struct hfs_bnode *node;
79 u32 nidx;
80 int i, res = 1;
81
82 switch (inode->i_ino) {
83 case HFS_EXT_CNID:
84 tree = HFS_SB(sb)->ext_tree;
85 break;
86 case HFS_CAT_CNID:
87 tree = HFS_SB(sb)->cat_tree;
88 break;
89 default:
90 BUG();
91 return 0;
92 }
93
94 if (!tree)
95 return 0;
96
97 if (tree->node_size >= PAGE_SIZE) {
98 nidx = page->index >> (tree->node_size_shift - PAGE_SHIFT);
99 spin_lock(&tree->hash_lock);
100 node = hfs_bnode_findhash(tree, nidx);
101 if (!node)
102 ;
103 else if (atomic_read(&node->refcnt))
104 res = 0;
105 if (res && node) {
106 hfs_bnode_unhash(node);
107 hfs_bnode_free(node);
108 }
109 spin_unlock(&tree->hash_lock);
110 } else {
111 nidx = page->index << (PAGE_SHIFT - tree->node_size_shift);
112 i = 1 << (PAGE_SHIFT - tree->node_size_shift);
113 spin_lock(&tree->hash_lock);
114 do {
115 node = hfs_bnode_findhash(tree, nidx++);
116 if (!node)
117 continue;
118 if (atomic_read(&node->refcnt)) {
119 res = 0;
120 break;
121 }
122 hfs_bnode_unhash(node);
123 hfs_bnode_free(node);
124 } while (--i && nidx < tree->node_count);
125 spin_unlock(&tree->hash_lock);
126 }
127 return res ? try_to_free_buffers(page) : 0;
128 }
129
hfs_direct_IO(struct kiocb * iocb,struct iov_iter * iter)130 static ssize_t hfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
131 {
132 struct file *file = iocb->ki_filp;
133 struct address_space *mapping = file->f_mapping;
134 struct inode *inode = mapping->host;
135 size_t count = iov_iter_count(iter);
136 ssize_t ret;
137
138 ret = blockdev_direct_IO(iocb, inode, iter, hfs_get_block);
139
140 /*
141 * In case of error extending write may have instantiated a few
142 * blocks outside i_size. Trim these off again.
143 */
144 if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
145 loff_t isize = i_size_read(inode);
146 loff_t end = iocb->ki_pos + count;
147
148 if (end > isize)
149 hfs_write_failed(mapping, end);
150 }
151
152 return ret;
153 }
154
hfs_writepages(struct address_space * mapping,struct writeback_control * wbc)155 static int hfs_writepages(struct address_space *mapping,
156 struct writeback_control *wbc)
157 {
158 return mpage_writepages(mapping, wbc, hfs_get_block);
159 }
160
161 const struct address_space_operations hfs_btree_aops = {
162 .set_page_dirty = __set_page_dirty_buffers,
163 .readpage = hfs_readpage,
164 .writepage = hfs_writepage,
165 .write_begin = hfs_write_begin,
166 .write_end = generic_write_end,
167 .bmap = hfs_bmap,
168 .releasepage = hfs_releasepage,
169 };
170
171 const struct address_space_operations hfs_aops = {
172 .set_page_dirty = __set_page_dirty_buffers,
173 .readpage = hfs_readpage,
174 .writepage = hfs_writepage,
175 .write_begin = hfs_write_begin,
176 .write_end = generic_write_end,
177 .bmap = hfs_bmap,
178 .direct_IO = hfs_direct_IO,
179 .writepages = hfs_writepages,
180 };
181
182 /*
183 * hfs_new_inode
184 */
hfs_new_inode(struct inode * dir,const struct qstr * name,umode_t mode)185 struct inode *hfs_new_inode(struct inode *dir, const struct qstr *name, umode_t mode)
186 {
187 struct super_block *sb = dir->i_sb;
188 struct inode *inode = new_inode(sb);
189 if (!inode)
190 return NULL;
191
192 mutex_init(&HFS_I(inode)->extents_lock);
193 INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
194 spin_lock_init(&HFS_I(inode)->open_dir_lock);
195 hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, name);
196 inode->i_ino = HFS_SB(sb)->next_id++;
197 inode->i_mode = mode;
198 inode->i_uid = current_fsuid();
199 inode->i_gid = current_fsgid();
200 set_nlink(inode, 1);
201 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
202 HFS_I(inode)->flags = 0;
203 HFS_I(inode)->rsrc_inode = NULL;
204 HFS_I(inode)->fs_blocks = 0;
205 if (S_ISDIR(mode)) {
206 inode->i_size = 2;
207 HFS_SB(sb)->folder_count++;
208 if (dir->i_ino == HFS_ROOT_CNID)
209 HFS_SB(sb)->root_dirs++;
210 inode->i_op = &hfs_dir_inode_operations;
211 inode->i_fop = &hfs_dir_operations;
212 inode->i_mode |= S_IRWXUGO;
213 inode->i_mode &= ~HFS_SB(inode->i_sb)->s_dir_umask;
214 } else if (S_ISREG(mode)) {
215 HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
216 HFS_SB(sb)->file_count++;
217 if (dir->i_ino == HFS_ROOT_CNID)
218 HFS_SB(sb)->root_files++;
219 inode->i_op = &hfs_file_inode_operations;
220 inode->i_fop = &hfs_file_operations;
221 inode->i_mapping->a_ops = &hfs_aops;
222 inode->i_mode |= S_IRUGO|S_IXUGO;
223 if (mode & S_IWUSR)
224 inode->i_mode |= S_IWUGO;
225 inode->i_mode &= ~HFS_SB(inode->i_sb)->s_file_umask;
226 HFS_I(inode)->phys_size = 0;
227 HFS_I(inode)->alloc_blocks = 0;
228 HFS_I(inode)->first_blocks = 0;
229 HFS_I(inode)->cached_start = 0;
230 HFS_I(inode)->cached_blocks = 0;
231 memset(HFS_I(inode)->first_extents, 0, sizeof(hfs_extent_rec));
232 memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
233 }
234 insert_inode_hash(inode);
235 mark_inode_dirty(inode);
236 set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
237 hfs_mark_mdb_dirty(sb);
238
239 return inode;
240 }
241
hfs_delete_inode(struct inode * inode)242 void hfs_delete_inode(struct inode *inode)
243 {
244 struct super_block *sb = inode->i_sb;
245
246 hfs_dbg(INODE, "delete_inode: %lu\n", inode->i_ino);
247 if (S_ISDIR(inode->i_mode)) {
248 HFS_SB(sb)->folder_count--;
249 if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
250 HFS_SB(sb)->root_dirs--;
251 set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
252 hfs_mark_mdb_dirty(sb);
253 return;
254 }
255 HFS_SB(sb)->file_count--;
256 if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
257 HFS_SB(sb)->root_files--;
258 if (S_ISREG(inode->i_mode)) {
259 if (!inode->i_nlink) {
260 inode->i_size = 0;
261 hfs_file_truncate(inode);
262 }
263 }
264 set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
265 hfs_mark_mdb_dirty(sb);
266 }
267
hfs_inode_read_fork(struct inode * inode,struct hfs_extent * ext,__be32 __log_size,__be32 phys_size,u32 clump_size)268 void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
269 __be32 __log_size, __be32 phys_size, u32 clump_size)
270 {
271 struct super_block *sb = inode->i_sb;
272 u32 log_size = be32_to_cpu(__log_size);
273 u16 count;
274 int i;
275
276 memcpy(HFS_I(inode)->first_extents, ext, sizeof(hfs_extent_rec));
277 for (count = 0, i = 0; i < 3; i++)
278 count += be16_to_cpu(ext[i].count);
279 HFS_I(inode)->first_blocks = count;
280
281 inode->i_size = HFS_I(inode)->phys_size = log_size;
282 HFS_I(inode)->fs_blocks = (log_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
283 inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
284 HFS_I(inode)->alloc_blocks = be32_to_cpu(phys_size) /
285 HFS_SB(sb)->alloc_blksz;
286 HFS_I(inode)->clump_blocks = clump_size / HFS_SB(sb)->alloc_blksz;
287 if (!HFS_I(inode)->clump_blocks)
288 HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
289 }
290
291 struct hfs_iget_data {
292 struct hfs_cat_key *key;
293 hfs_cat_rec *rec;
294 };
295
hfs_test_inode(struct inode * inode,void * data)296 static int hfs_test_inode(struct inode *inode, void *data)
297 {
298 struct hfs_iget_data *idata = data;
299 hfs_cat_rec *rec;
300
301 rec = idata->rec;
302 switch (rec->type) {
303 case HFS_CDR_DIR:
304 return inode->i_ino == be32_to_cpu(rec->dir.DirID);
305 case HFS_CDR_FIL:
306 return inode->i_ino == be32_to_cpu(rec->file.FlNum);
307 default:
308 BUG();
309 return 1;
310 }
311 }
312
313 /*
314 * hfs_read_inode
315 */
hfs_read_inode(struct inode * inode,void * data)316 static int hfs_read_inode(struct inode *inode, void *data)
317 {
318 struct hfs_iget_data *idata = data;
319 struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
320 hfs_cat_rec *rec;
321
322 HFS_I(inode)->flags = 0;
323 HFS_I(inode)->rsrc_inode = NULL;
324 mutex_init(&HFS_I(inode)->extents_lock);
325 INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
326 spin_lock_init(&HFS_I(inode)->open_dir_lock);
327
328 /* Initialize the inode */
329 inode->i_uid = hsb->s_uid;
330 inode->i_gid = hsb->s_gid;
331 set_nlink(inode, 1);
332
333 if (idata->key)
334 HFS_I(inode)->cat_key = *idata->key;
335 else
336 HFS_I(inode)->flags |= HFS_FLG_RSRC;
337 HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
338
339 rec = idata->rec;
340 switch (rec->type) {
341 case HFS_CDR_FIL:
342 if (!HFS_IS_RSRC(inode)) {
343 hfs_inode_read_fork(inode, rec->file.ExtRec, rec->file.LgLen,
344 rec->file.PyLen, be16_to_cpu(rec->file.ClpSize));
345 } else {
346 hfs_inode_read_fork(inode, rec->file.RExtRec, rec->file.RLgLen,
347 rec->file.RPyLen, be16_to_cpu(rec->file.ClpSize));
348 }
349
350 inode->i_ino = be32_to_cpu(rec->file.FlNum);
351 inode->i_mode = S_IRUGO | S_IXUGO;
352 if (!(rec->file.Flags & HFS_FIL_LOCK))
353 inode->i_mode |= S_IWUGO;
354 inode->i_mode &= ~hsb->s_file_umask;
355 inode->i_mode |= S_IFREG;
356 inode->i_ctime = inode->i_atime = inode->i_mtime =
357 hfs_m_to_utime(rec->file.MdDat);
358 inode->i_op = &hfs_file_inode_operations;
359 inode->i_fop = &hfs_file_operations;
360 inode->i_mapping->a_ops = &hfs_aops;
361 break;
362 case HFS_CDR_DIR:
363 inode->i_ino = be32_to_cpu(rec->dir.DirID);
364 inode->i_size = be16_to_cpu(rec->dir.Val) + 2;
365 HFS_I(inode)->fs_blocks = 0;
366 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~hsb->s_dir_umask);
367 inode->i_ctime = inode->i_atime = inode->i_mtime =
368 hfs_m_to_utime(rec->dir.MdDat);
369 inode->i_op = &hfs_dir_inode_operations;
370 inode->i_fop = &hfs_dir_operations;
371 break;
372 default:
373 make_bad_inode(inode);
374 }
375 return 0;
376 }
377
378 /*
379 * __hfs_iget()
380 *
381 * Given the MDB for a HFS filesystem, a 'key' and an 'entry' in
382 * the catalog B-tree and the 'type' of the desired file return the
383 * inode for that file/directory or NULL. Note that 'type' indicates
384 * whether we want the actual file or directory, or the corresponding
385 * metadata (AppleDouble header file or CAP metadata file).
386 */
hfs_iget(struct super_block * sb,struct hfs_cat_key * key,hfs_cat_rec * rec)387 struct inode *hfs_iget(struct super_block *sb, struct hfs_cat_key *key, hfs_cat_rec *rec)
388 {
389 struct hfs_iget_data data = { key, rec };
390 struct inode *inode;
391 u32 cnid;
392
393 switch (rec->type) {
394 case HFS_CDR_DIR:
395 cnid = be32_to_cpu(rec->dir.DirID);
396 break;
397 case HFS_CDR_FIL:
398 cnid = be32_to_cpu(rec->file.FlNum);
399 break;
400 default:
401 return NULL;
402 }
403 inode = iget5_locked(sb, cnid, hfs_test_inode, hfs_read_inode, &data);
404 if (inode && (inode->i_state & I_NEW))
405 unlock_new_inode(inode);
406 return inode;
407 }
408
hfs_inode_write_fork(struct inode * inode,struct hfs_extent * ext,__be32 * log_size,__be32 * phys_size)409 void hfs_inode_write_fork(struct inode *inode, struct hfs_extent *ext,
410 __be32 *log_size, __be32 *phys_size)
411 {
412 memcpy(ext, HFS_I(inode)->first_extents, sizeof(hfs_extent_rec));
413
414 if (log_size)
415 *log_size = cpu_to_be32(inode->i_size);
416 if (phys_size)
417 *phys_size = cpu_to_be32(HFS_I(inode)->alloc_blocks *
418 HFS_SB(inode->i_sb)->alloc_blksz);
419 }
420
hfs_write_inode(struct inode * inode,struct writeback_control * wbc)421 int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
422 {
423 struct inode *main_inode = inode;
424 struct hfs_find_data fd;
425 hfs_cat_rec rec;
426 int res;
427
428 hfs_dbg(INODE, "hfs_write_inode: %lu\n", inode->i_ino);
429 res = hfs_ext_write_extent(inode);
430 if (res)
431 return res;
432
433 if (inode->i_ino < HFS_FIRSTUSER_CNID) {
434 switch (inode->i_ino) {
435 case HFS_ROOT_CNID:
436 break;
437 case HFS_EXT_CNID:
438 hfs_btree_write(HFS_SB(inode->i_sb)->ext_tree);
439 return 0;
440 case HFS_CAT_CNID:
441 hfs_btree_write(HFS_SB(inode->i_sb)->cat_tree);
442 return 0;
443 default:
444 BUG();
445 return -EIO;
446 }
447 }
448
449 if (HFS_IS_RSRC(inode))
450 main_inode = HFS_I(inode)->rsrc_inode;
451
452 if (!main_inode->i_nlink)
453 return 0;
454
455 if (hfs_find_init(HFS_SB(main_inode->i_sb)->cat_tree, &fd))
456 /* panic? */
457 return -EIO;
458
459 fd.search_key->cat = HFS_I(main_inode)->cat_key;
460 if (hfs_brec_find(&fd))
461 /* panic? */
462 goto out;
463
464 if (S_ISDIR(main_inode->i_mode)) {
465 WARN_ON(fd.entrylength < sizeof(struct hfs_cat_dir));
466 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
467 sizeof(struct hfs_cat_dir));
468 if (rec.type != HFS_CDR_DIR ||
469 be32_to_cpu(rec.dir.DirID) != inode->i_ino) {
470 }
471
472 rec.dir.MdDat = hfs_u_to_mtime(inode->i_mtime);
473 rec.dir.Val = cpu_to_be16(inode->i_size - 2);
474
475 hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
476 sizeof(struct hfs_cat_dir));
477 } else if (HFS_IS_RSRC(inode)) {
478 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
479 sizeof(struct hfs_cat_file));
480 hfs_inode_write_fork(inode, rec.file.RExtRec,
481 &rec.file.RLgLen, &rec.file.RPyLen);
482 hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
483 sizeof(struct hfs_cat_file));
484 } else {
485 WARN_ON(fd.entrylength < sizeof(struct hfs_cat_file));
486 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
487 sizeof(struct hfs_cat_file));
488 if (rec.type != HFS_CDR_FIL ||
489 be32_to_cpu(rec.file.FlNum) != inode->i_ino) {
490 }
491
492 if (inode->i_mode & S_IWUSR)
493 rec.file.Flags &= ~HFS_FIL_LOCK;
494 else
495 rec.file.Flags |= HFS_FIL_LOCK;
496 hfs_inode_write_fork(inode, rec.file.ExtRec, &rec.file.LgLen, &rec.file.PyLen);
497 rec.file.MdDat = hfs_u_to_mtime(inode->i_mtime);
498
499 hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
500 sizeof(struct hfs_cat_file));
501 }
502 out:
503 hfs_find_exit(&fd);
504 return 0;
505 }
506
hfs_file_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)507 static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
508 unsigned int flags)
509 {
510 struct inode *inode = NULL;
511 hfs_cat_rec rec;
512 struct hfs_find_data fd;
513 int res;
514
515 if (HFS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc"))
516 goto out;
517
518 inode = HFS_I(dir)->rsrc_inode;
519 if (inode)
520 goto out;
521
522 inode = new_inode(dir->i_sb);
523 if (!inode)
524 return ERR_PTR(-ENOMEM);
525
526 res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
527 if (res) {
528 iput(inode);
529 return ERR_PTR(res);
530 }
531 fd.search_key->cat = HFS_I(dir)->cat_key;
532 res = hfs_brec_read(&fd, &rec, sizeof(rec));
533 if (!res) {
534 struct hfs_iget_data idata = { NULL, &rec };
535 hfs_read_inode(inode, &idata);
536 }
537 hfs_find_exit(&fd);
538 if (res) {
539 iput(inode);
540 return ERR_PTR(res);
541 }
542 HFS_I(inode)->rsrc_inode = dir;
543 HFS_I(dir)->rsrc_inode = inode;
544 igrab(dir);
545 inode_fake_hash(inode);
546 mark_inode_dirty(inode);
547 dont_mount(dentry);
548 out:
549 return d_splice_alias(inode, dentry);
550 }
551
hfs_evict_inode(struct inode * inode)552 void hfs_evict_inode(struct inode *inode)
553 {
554 truncate_inode_pages_final(&inode->i_data);
555 clear_inode(inode);
556 if (HFS_IS_RSRC(inode) && HFS_I(inode)->rsrc_inode) {
557 HFS_I(HFS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
558 iput(HFS_I(inode)->rsrc_inode);
559 }
560 }
561
hfs_file_open(struct inode * inode,struct file * file)562 static int hfs_file_open(struct inode *inode, struct file *file)
563 {
564 if (HFS_IS_RSRC(inode))
565 inode = HFS_I(inode)->rsrc_inode;
566 atomic_inc(&HFS_I(inode)->opencnt);
567 return 0;
568 }
569
hfs_file_release(struct inode * inode,struct file * file)570 static int hfs_file_release(struct inode *inode, struct file *file)
571 {
572 //struct super_block *sb = inode->i_sb;
573
574 if (HFS_IS_RSRC(inode))
575 inode = HFS_I(inode)->rsrc_inode;
576 if (atomic_dec_and_test(&HFS_I(inode)->opencnt)) {
577 inode_lock(inode);
578 hfs_file_truncate(inode);
579 //if (inode->i_flags & S_DEAD) {
580 // hfs_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
581 // hfs_delete_inode(inode);
582 //}
583 inode_unlock(inode);
584 }
585 return 0;
586 }
587
588 /*
589 * hfs_notify_change()
590 *
591 * Based very closely on fs/msdos/inode.c by Werner Almesberger
592 *
593 * This is the notify_change() field in the super_operations structure
594 * for HFS file systems. The purpose is to take that changes made to
595 * an inode and apply then in a filesystem-dependent manner. In this
596 * case the process has a few of tasks to do:
597 * 1) prevent changes to the i_uid and i_gid fields.
598 * 2) map file permissions to the closest allowable permissions
599 * 3) Since multiple Linux files can share the same on-disk inode under
600 * HFS (for instance the data and resource forks of a file) a change
601 * to permissions must be applied to all other in-core inodes which
602 * correspond to the same HFS file.
603 */
604
hfs_inode_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * attr)605 int hfs_inode_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
606 struct iattr *attr)
607 {
608 struct inode *inode = d_inode(dentry);
609 struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
610 int error;
611
612 error = setattr_prepare(&init_user_ns, dentry,
613 attr); /* basic permission checks */
614 if (error)
615 return error;
616
617 /* no uig/gid changes and limit which mode bits can be set */
618 if (((attr->ia_valid & ATTR_UID) &&
619 (!uid_eq(attr->ia_uid, hsb->s_uid))) ||
620 ((attr->ia_valid & ATTR_GID) &&
621 (!gid_eq(attr->ia_gid, hsb->s_gid))) ||
622 ((attr->ia_valid & ATTR_MODE) &&
623 ((S_ISDIR(inode->i_mode) &&
624 (attr->ia_mode != inode->i_mode)) ||
625 (attr->ia_mode & ~HFS_VALID_MODE_BITS)))) {
626 return hsb->s_quiet ? 0 : error;
627 }
628
629 if (attr->ia_valid & ATTR_MODE) {
630 /* Only the 'w' bits can ever change and only all together. */
631 if (attr->ia_mode & S_IWUSR)
632 attr->ia_mode = inode->i_mode | S_IWUGO;
633 else
634 attr->ia_mode = inode->i_mode & ~S_IWUGO;
635 attr->ia_mode &= S_ISDIR(inode->i_mode) ? ~hsb->s_dir_umask: ~hsb->s_file_umask;
636 }
637
638 if ((attr->ia_valid & ATTR_SIZE) &&
639 attr->ia_size != i_size_read(inode)) {
640 inode_dio_wait(inode);
641
642 error = inode_newsize_ok(inode, attr->ia_size);
643 if (error)
644 return error;
645
646 truncate_setsize(inode, attr->ia_size);
647 hfs_file_truncate(inode);
648 inode->i_atime = inode->i_mtime = inode->i_ctime =
649 current_time(inode);
650 }
651
652 setattr_copy(&init_user_ns, inode, attr);
653 mark_inode_dirty(inode);
654 return 0;
655 }
656
hfs_file_fsync(struct file * filp,loff_t start,loff_t end,int datasync)657 static int hfs_file_fsync(struct file *filp, loff_t start, loff_t end,
658 int datasync)
659 {
660 struct inode *inode = filp->f_mapping->host;
661 struct super_block * sb;
662 int ret, err;
663
664 ret = file_write_and_wait_range(filp, start, end);
665 if (ret)
666 return ret;
667 inode_lock(inode);
668
669 /* sync the inode to buffers */
670 ret = write_inode_now(inode, 0);
671
672 /* sync the superblock to buffers */
673 sb = inode->i_sb;
674 flush_delayed_work(&HFS_SB(sb)->mdb_work);
675 /* .. finally sync the buffers to disk */
676 err = sync_blockdev(sb->s_bdev);
677 if (!ret)
678 ret = err;
679 inode_unlock(inode);
680 return ret;
681 }
682
683 static const struct file_operations hfs_file_operations = {
684 .llseek = generic_file_llseek,
685 .read_iter = generic_file_read_iter,
686 .write_iter = generic_file_write_iter,
687 .mmap = generic_file_mmap,
688 .splice_read = generic_file_splice_read,
689 .fsync = hfs_file_fsync,
690 .open = hfs_file_open,
691 .release = hfs_file_release,
692 };
693
694 static const struct inode_operations hfs_file_inode_operations = {
695 .lookup = hfs_file_lookup,
696 .setattr = hfs_inode_setattr,
697 .listxattr = generic_listxattr,
698 };
699