xref: /linux/fs/hfs/inode.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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 
32 static int hfs_read_folio(struct file *file, struct folio *folio)
33 {
34 	return block_read_full_folio(folio, hfs_get_block);
35 }
36 
37 static void hfs_write_failed(struct address_space *mapping, loff_t to)
38 {
39 	struct inode *inode = mapping->host;
40 
41 	if (to > inode->i_size) {
42 		truncate_pagecache(inode, inode->i_size);
43 		hfs_file_truncate(inode);
44 	}
45 }
46 
47 int hfs_write_begin(struct file *file, struct address_space *mapping,
48 		loff_t pos, unsigned len, struct page **pagep, void **fsdata)
49 {
50 	int ret;
51 
52 	*pagep = NULL;
53 	ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata,
54 				hfs_get_block,
55 				&HFS_I(mapping->host)->phys_size);
56 	if (unlikely(ret))
57 		hfs_write_failed(mapping, pos + len);
58 
59 	return ret;
60 }
61 
62 static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
63 {
64 	return generic_block_bmap(mapping, block, hfs_get_block);
65 }
66 
67 static bool hfs_release_folio(struct folio *folio, gfp_t mask)
68 {
69 	struct inode *inode = folio->mapping->host;
70 	struct super_block *sb = inode->i_sb;
71 	struct hfs_btree *tree;
72 	struct hfs_bnode *node;
73 	u32 nidx;
74 	int i;
75 	bool res = true;
76 
77 	switch (inode->i_ino) {
78 	case HFS_EXT_CNID:
79 		tree = HFS_SB(sb)->ext_tree;
80 		break;
81 	case HFS_CAT_CNID:
82 		tree = HFS_SB(sb)->cat_tree;
83 		break;
84 	default:
85 		BUG();
86 		return false;
87 	}
88 
89 	if (!tree)
90 		return false;
91 
92 	if (tree->node_size >= PAGE_SIZE) {
93 		nidx = folio->index >> (tree->node_size_shift - PAGE_SHIFT);
94 		spin_lock(&tree->hash_lock);
95 		node = hfs_bnode_findhash(tree, nidx);
96 		if (!node)
97 			;
98 		else if (atomic_read(&node->refcnt))
99 			res = false;
100 		if (res && node) {
101 			hfs_bnode_unhash(node);
102 			hfs_bnode_free(node);
103 		}
104 		spin_unlock(&tree->hash_lock);
105 	} else {
106 		nidx = folio->index << (PAGE_SHIFT - tree->node_size_shift);
107 		i = 1 << (PAGE_SHIFT - tree->node_size_shift);
108 		spin_lock(&tree->hash_lock);
109 		do {
110 			node = hfs_bnode_findhash(tree, nidx++);
111 			if (!node)
112 				continue;
113 			if (atomic_read(&node->refcnt)) {
114 				res = false;
115 				break;
116 			}
117 			hfs_bnode_unhash(node);
118 			hfs_bnode_free(node);
119 		} while (--i && nidx < tree->node_count);
120 		spin_unlock(&tree->hash_lock);
121 	}
122 	return res ? try_to_free_buffers(folio) : false;
123 }
124 
125 static ssize_t hfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
126 {
127 	struct file *file = iocb->ki_filp;
128 	struct address_space *mapping = file->f_mapping;
129 	struct inode *inode = mapping->host;
130 	size_t count = iov_iter_count(iter);
131 	ssize_t ret;
132 
133 	ret = blockdev_direct_IO(iocb, inode, iter, hfs_get_block);
134 
135 	/*
136 	 * In case of error extending write may have instantiated a few
137 	 * blocks outside i_size. Trim these off again.
138 	 */
139 	if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
140 		loff_t isize = i_size_read(inode);
141 		loff_t end = iocb->ki_pos + count;
142 
143 		if (end > isize)
144 			hfs_write_failed(mapping, end);
145 	}
146 
147 	return ret;
148 }
149 
150 static int hfs_writepages(struct address_space *mapping,
151 			  struct writeback_control *wbc)
152 {
153 	return mpage_writepages(mapping, wbc, hfs_get_block);
154 }
155 
156 const struct address_space_operations hfs_btree_aops = {
157 	.dirty_folio	= block_dirty_folio,
158 	.invalidate_folio = block_invalidate_folio,
159 	.read_folio	= hfs_read_folio,
160 	.writepages	= hfs_writepages,
161 	.write_begin	= hfs_write_begin,
162 	.write_end	= generic_write_end,
163 	.migrate_folio	= buffer_migrate_folio,
164 	.bmap		= hfs_bmap,
165 	.release_folio	= hfs_release_folio,
166 };
167 
168 const struct address_space_operations hfs_aops = {
169 	.dirty_folio	= block_dirty_folio,
170 	.invalidate_folio = block_invalidate_folio,
171 	.read_folio	= hfs_read_folio,
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 	.migrate_folio	= buffer_migrate_folio,
178 };
179 
180 /*
181  * hfs_new_inode
182  */
183 struct inode *hfs_new_inode(struct inode *dir, const struct qstr *name, umode_t mode)
184 {
185 	struct super_block *sb = dir->i_sb;
186 	struct inode *inode = new_inode(sb);
187 	if (!inode)
188 		return NULL;
189 
190 	mutex_init(&HFS_I(inode)->extents_lock);
191 	INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
192 	spin_lock_init(&HFS_I(inode)->open_dir_lock);
193 	hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, name);
194 	inode->i_ino = HFS_SB(sb)->next_id++;
195 	inode->i_mode = mode;
196 	inode->i_uid = current_fsuid();
197 	inode->i_gid = current_fsgid();
198 	set_nlink(inode, 1);
199 	simple_inode_init_ts(inode);
200 	HFS_I(inode)->flags = 0;
201 	HFS_I(inode)->rsrc_inode = NULL;
202 	HFS_I(inode)->fs_blocks = 0;
203 	if (S_ISDIR(mode)) {
204 		inode->i_size = 2;
205 		HFS_SB(sb)->folder_count++;
206 		if (dir->i_ino == HFS_ROOT_CNID)
207 			HFS_SB(sb)->root_dirs++;
208 		inode->i_op = &hfs_dir_inode_operations;
209 		inode->i_fop = &hfs_dir_operations;
210 		inode->i_mode |= S_IRWXUGO;
211 		inode->i_mode &= ~HFS_SB(inode->i_sb)->s_dir_umask;
212 	} else if (S_ISREG(mode)) {
213 		HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
214 		HFS_SB(sb)->file_count++;
215 		if (dir->i_ino == HFS_ROOT_CNID)
216 			HFS_SB(sb)->root_files++;
217 		inode->i_op = &hfs_file_inode_operations;
218 		inode->i_fop = &hfs_file_operations;
219 		inode->i_mapping->a_ops = &hfs_aops;
220 		inode->i_mode |= S_IRUGO|S_IXUGO;
221 		if (mode & S_IWUSR)
222 			inode->i_mode |= S_IWUGO;
223 		inode->i_mode &= ~HFS_SB(inode->i_sb)->s_file_umask;
224 		HFS_I(inode)->phys_size = 0;
225 		HFS_I(inode)->alloc_blocks = 0;
226 		HFS_I(inode)->first_blocks = 0;
227 		HFS_I(inode)->cached_start = 0;
228 		HFS_I(inode)->cached_blocks = 0;
229 		memset(HFS_I(inode)->first_extents, 0, sizeof(hfs_extent_rec));
230 		memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
231 	}
232 	insert_inode_hash(inode);
233 	mark_inode_dirty(inode);
234 	set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
235 	hfs_mark_mdb_dirty(sb);
236 
237 	return inode;
238 }
239 
240 void hfs_delete_inode(struct inode *inode)
241 {
242 	struct super_block *sb = inode->i_sb;
243 
244 	hfs_dbg(INODE, "delete_inode: %lu\n", inode->i_ino);
245 	if (S_ISDIR(inode->i_mode)) {
246 		HFS_SB(sb)->folder_count--;
247 		if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
248 			HFS_SB(sb)->root_dirs--;
249 		set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
250 		hfs_mark_mdb_dirty(sb);
251 		return;
252 	}
253 	HFS_SB(sb)->file_count--;
254 	if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
255 		HFS_SB(sb)->root_files--;
256 	if (S_ISREG(inode->i_mode)) {
257 		if (!inode->i_nlink) {
258 			inode->i_size = 0;
259 			hfs_file_truncate(inode);
260 		}
261 	}
262 	set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
263 	hfs_mark_mdb_dirty(sb);
264 }
265 
266 void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
267 			 __be32 __log_size, __be32 phys_size, u32 clump_size)
268 {
269 	struct super_block *sb = inode->i_sb;
270 	u32 log_size = be32_to_cpu(__log_size);
271 	u16 count;
272 	int i;
273 
274 	memcpy(HFS_I(inode)->first_extents, ext, sizeof(hfs_extent_rec));
275 	for (count = 0, i = 0; i < 3; i++)
276 		count += be16_to_cpu(ext[i].count);
277 	HFS_I(inode)->first_blocks = count;
278 
279 	inode->i_size = HFS_I(inode)->phys_size = log_size;
280 	HFS_I(inode)->fs_blocks = (log_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
281 	inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
282 	HFS_I(inode)->alloc_blocks = be32_to_cpu(phys_size) /
283 				     HFS_SB(sb)->alloc_blksz;
284 	HFS_I(inode)->clump_blocks = clump_size / HFS_SB(sb)->alloc_blksz;
285 	if (!HFS_I(inode)->clump_blocks)
286 		HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
287 }
288 
289 struct hfs_iget_data {
290 	struct hfs_cat_key *key;
291 	hfs_cat_rec *rec;
292 };
293 
294 static int hfs_test_inode(struct inode *inode, void *data)
295 {
296 	struct hfs_iget_data *idata = data;
297 	hfs_cat_rec *rec;
298 
299 	rec = idata->rec;
300 	switch (rec->type) {
301 	case HFS_CDR_DIR:
302 		return inode->i_ino == be32_to_cpu(rec->dir.DirID);
303 	case HFS_CDR_FIL:
304 		return inode->i_ino == be32_to_cpu(rec->file.FlNum);
305 	default:
306 		BUG();
307 		return 1;
308 	}
309 }
310 
311 /*
312  * hfs_read_inode
313  */
314 static int hfs_read_inode(struct inode *inode, void *data)
315 {
316 	struct hfs_iget_data *idata = data;
317 	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
318 	hfs_cat_rec *rec;
319 
320 	HFS_I(inode)->flags = 0;
321 	HFS_I(inode)->rsrc_inode = NULL;
322 	mutex_init(&HFS_I(inode)->extents_lock);
323 	INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
324 	spin_lock_init(&HFS_I(inode)->open_dir_lock);
325 
326 	/* Initialize the inode */
327 	inode->i_uid = hsb->s_uid;
328 	inode->i_gid = hsb->s_gid;
329 	set_nlink(inode, 1);
330 
331 	if (idata->key)
332 		HFS_I(inode)->cat_key = *idata->key;
333 	else
334 		HFS_I(inode)->flags |= HFS_FLG_RSRC;
335 	HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
336 
337 	rec = idata->rec;
338 	switch (rec->type) {
339 	case HFS_CDR_FIL:
340 		if (!HFS_IS_RSRC(inode)) {
341 			hfs_inode_read_fork(inode, rec->file.ExtRec, rec->file.LgLen,
342 					    rec->file.PyLen, be16_to_cpu(rec->file.ClpSize));
343 		} else {
344 			hfs_inode_read_fork(inode, rec->file.RExtRec, rec->file.RLgLen,
345 					    rec->file.RPyLen, be16_to_cpu(rec->file.ClpSize));
346 		}
347 
348 		inode->i_ino = be32_to_cpu(rec->file.FlNum);
349 		inode->i_mode = S_IRUGO | S_IXUGO;
350 		if (!(rec->file.Flags & HFS_FIL_LOCK))
351 			inode->i_mode |= S_IWUGO;
352 		inode->i_mode &= ~hsb->s_file_umask;
353 		inode->i_mode |= S_IFREG;
354 		inode_set_mtime_to_ts(inode,
355 				      inode_set_atime_to_ts(inode, inode_set_ctime_to_ts(inode, hfs_m_to_utime(rec->file.MdDat))));
356 		inode->i_op = &hfs_file_inode_operations;
357 		inode->i_fop = &hfs_file_operations;
358 		inode->i_mapping->a_ops = &hfs_aops;
359 		break;
360 	case HFS_CDR_DIR:
361 		inode->i_ino = be32_to_cpu(rec->dir.DirID);
362 		inode->i_size = be16_to_cpu(rec->dir.Val) + 2;
363 		HFS_I(inode)->fs_blocks = 0;
364 		inode->i_mode = S_IFDIR | (S_IRWXUGO & ~hsb->s_dir_umask);
365 		inode_set_mtime_to_ts(inode,
366 				      inode_set_atime_to_ts(inode, inode_set_ctime_to_ts(inode, hfs_m_to_utime(rec->dir.MdDat))));
367 		inode->i_op = &hfs_dir_inode_operations;
368 		inode->i_fop = &hfs_dir_operations;
369 		break;
370 	default:
371 		make_bad_inode(inode);
372 	}
373 	return 0;
374 }
375 
376 /*
377  * __hfs_iget()
378  *
379  * Given the MDB for a HFS filesystem, a 'key' and an 'entry' in
380  * the catalog B-tree and the 'type' of the desired file return the
381  * inode for that file/directory or NULL.  Note that 'type' indicates
382  * whether we want the actual file or directory, or the corresponding
383  * metadata (AppleDouble header file or CAP metadata file).
384  */
385 struct inode *hfs_iget(struct super_block *sb, struct hfs_cat_key *key, hfs_cat_rec *rec)
386 {
387 	struct hfs_iget_data data = { key, rec };
388 	struct inode *inode;
389 	u32 cnid;
390 
391 	switch (rec->type) {
392 	case HFS_CDR_DIR:
393 		cnid = be32_to_cpu(rec->dir.DirID);
394 		break;
395 	case HFS_CDR_FIL:
396 		cnid = be32_to_cpu(rec->file.FlNum);
397 		break;
398 	default:
399 		return NULL;
400 	}
401 	inode = iget5_locked(sb, cnid, hfs_test_inode, hfs_read_inode, &data);
402 	if (inode && (inode->i_state & I_NEW))
403 		unlock_new_inode(inode);
404 	return inode;
405 }
406 
407 void hfs_inode_write_fork(struct inode *inode, struct hfs_extent *ext,
408 			  __be32 *log_size, __be32 *phys_size)
409 {
410 	memcpy(ext, HFS_I(inode)->first_extents, sizeof(hfs_extent_rec));
411 
412 	if (log_size)
413 		*log_size = cpu_to_be32(inode->i_size);
414 	if (phys_size)
415 		*phys_size = cpu_to_be32(HFS_I(inode)->alloc_blocks *
416 					 HFS_SB(inode->i_sb)->alloc_blksz);
417 }
418 
419 int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
420 {
421 	struct inode *main_inode = inode;
422 	struct hfs_find_data fd;
423 	hfs_cat_rec rec;
424 	int res;
425 
426 	hfs_dbg(INODE, "hfs_write_inode: %lu\n", inode->i_ino);
427 	res = hfs_ext_write_extent(inode);
428 	if (res)
429 		return res;
430 
431 	if (inode->i_ino < HFS_FIRSTUSER_CNID) {
432 		switch (inode->i_ino) {
433 		case HFS_ROOT_CNID:
434 			break;
435 		case HFS_EXT_CNID:
436 			hfs_btree_write(HFS_SB(inode->i_sb)->ext_tree);
437 			return 0;
438 		case HFS_CAT_CNID:
439 			hfs_btree_write(HFS_SB(inode->i_sb)->cat_tree);
440 			return 0;
441 		default:
442 			BUG();
443 			return -EIO;
444 		}
445 	}
446 
447 	if (HFS_IS_RSRC(inode))
448 		main_inode = HFS_I(inode)->rsrc_inode;
449 
450 	if (!main_inode->i_nlink)
451 		return 0;
452 
453 	if (hfs_find_init(HFS_SB(main_inode->i_sb)->cat_tree, &fd))
454 		/* panic? */
455 		return -EIO;
456 
457 	res = -EIO;
458 	if (HFS_I(main_inode)->cat_key.CName.len > HFS_NAMELEN)
459 		goto out;
460 	fd.search_key->cat = HFS_I(main_inode)->cat_key;
461 	if (hfs_brec_find(&fd))
462 		goto out;
463 
464 	if (S_ISDIR(main_inode->i_mode)) {
465 		if (fd.entrylength < sizeof(struct hfs_cat_dir))
466 			goto out;
467 		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
468 			   sizeof(struct hfs_cat_dir));
469 		if (rec.type != HFS_CDR_DIR ||
470 		    be32_to_cpu(rec.dir.DirID) != inode->i_ino) {
471 		}
472 
473 		rec.dir.MdDat = hfs_u_to_mtime(inode_get_mtime(inode));
474 		rec.dir.Val = cpu_to_be16(inode->i_size - 2);
475 
476 		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
477 			    sizeof(struct hfs_cat_dir));
478 	} else if (HFS_IS_RSRC(inode)) {
479 		if (fd.entrylength < sizeof(struct hfs_cat_file))
480 			goto out;
481 		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
482 			       sizeof(struct hfs_cat_file));
483 		hfs_inode_write_fork(inode, rec.file.RExtRec,
484 				     &rec.file.RLgLen, &rec.file.RPyLen);
485 		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
486 				sizeof(struct hfs_cat_file));
487 	} else {
488 		if (fd.entrylength < sizeof(struct hfs_cat_file))
489 			goto out;
490 		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
491 			   sizeof(struct hfs_cat_file));
492 		if (rec.type != HFS_CDR_FIL ||
493 		    be32_to_cpu(rec.file.FlNum) != inode->i_ino) {
494 		}
495 
496 		if (inode->i_mode & S_IWUSR)
497 			rec.file.Flags &= ~HFS_FIL_LOCK;
498 		else
499 			rec.file.Flags |= HFS_FIL_LOCK;
500 		hfs_inode_write_fork(inode, rec.file.ExtRec, &rec.file.LgLen, &rec.file.PyLen);
501 		rec.file.MdDat = hfs_u_to_mtime(inode_get_mtime(inode));
502 
503 		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
504 			    sizeof(struct hfs_cat_file));
505 	}
506 	res = 0;
507 out:
508 	hfs_find_exit(&fd);
509 	return res;
510 }
511 
512 static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
513 				      unsigned int flags)
514 {
515 	struct inode *inode = NULL;
516 	hfs_cat_rec rec;
517 	struct hfs_find_data fd;
518 	int res;
519 
520 	if (HFS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc"))
521 		goto out;
522 
523 	inode = HFS_I(dir)->rsrc_inode;
524 	if (inode)
525 		goto out;
526 
527 	inode = new_inode(dir->i_sb);
528 	if (!inode)
529 		return ERR_PTR(-ENOMEM);
530 
531 	res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
532 	if (res) {
533 		iput(inode);
534 		return ERR_PTR(res);
535 	}
536 	fd.search_key->cat = HFS_I(dir)->cat_key;
537 	res = hfs_brec_read(&fd, &rec, sizeof(rec));
538 	if (!res) {
539 		struct hfs_iget_data idata = { NULL, &rec };
540 		hfs_read_inode(inode, &idata);
541 	}
542 	hfs_find_exit(&fd);
543 	if (res) {
544 		iput(inode);
545 		return ERR_PTR(res);
546 	}
547 	HFS_I(inode)->rsrc_inode = dir;
548 	HFS_I(dir)->rsrc_inode = inode;
549 	igrab(dir);
550 	inode_fake_hash(inode);
551 	mark_inode_dirty(inode);
552 	dont_mount(dentry);
553 out:
554 	return d_splice_alias(inode, dentry);
555 }
556 
557 void hfs_evict_inode(struct inode *inode)
558 {
559 	truncate_inode_pages_final(&inode->i_data);
560 	clear_inode(inode);
561 	if (HFS_IS_RSRC(inode) && HFS_I(inode)->rsrc_inode) {
562 		HFS_I(HFS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
563 		iput(HFS_I(inode)->rsrc_inode);
564 	}
565 }
566 
567 static int hfs_file_open(struct inode *inode, struct file *file)
568 {
569 	if (HFS_IS_RSRC(inode))
570 		inode = HFS_I(inode)->rsrc_inode;
571 	atomic_inc(&HFS_I(inode)->opencnt);
572 	return 0;
573 }
574 
575 static int hfs_file_release(struct inode *inode, struct file *file)
576 {
577 	//struct super_block *sb = inode->i_sb;
578 
579 	if (HFS_IS_RSRC(inode))
580 		inode = HFS_I(inode)->rsrc_inode;
581 	if (atomic_dec_and_test(&HFS_I(inode)->opencnt)) {
582 		inode_lock(inode);
583 		hfs_file_truncate(inode);
584 		//if (inode->i_flags & S_DEAD) {
585 		//	hfs_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
586 		//	hfs_delete_inode(inode);
587 		//}
588 		inode_unlock(inode);
589 	}
590 	return 0;
591 }
592 
593 /*
594  * hfs_notify_change()
595  *
596  * Based very closely on fs/msdos/inode.c by Werner Almesberger
597  *
598  * This is the notify_change() field in the super_operations structure
599  * for HFS file systems.  The purpose is to take that changes made to
600  * an inode and apply then in a filesystem-dependent manner.  In this
601  * case the process has a few of tasks to do:
602  *  1) prevent changes to the i_uid and i_gid fields.
603  *  2) map file permissions to the closest allowable permissions
604  *  3) Since multiple Linux files can share the same on-disk inode under
605  *     HFS (for instance the data and resource forks of a file) a change
606  *     to permissions must be applied to all other in-core inodes which
607  *     correspond to the same HFS file.
608  */
609 
610 int hfs_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
611 		      struct iattr *attr)
612 {
613 	struct inode *inode = d_inode(dentry);
614 	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
615 	int error;
616 
617 	error = setattr_prepare(&nop_mnt_idmap, dentry,
618 				attr); /* basic permission checks */
619 	if (error)
620 		return error;
621 
622 	/* no uig/gid changes and limit which mode bits can be set */
623 	if (((attr->ia_valid & ATTR_UID) &&
624 	     (!uid_eq(attr->ia_uid, hsb->s_uid))) ||
625 	    ((attr->ia_valid & ATTR_GID) &&
626 	     (!gid_eq(attr->ia_gid, hsb->s_gid))) ||
627 	    ((attr->ia_valid & ATTR_MODE) &&
628 	     ((S_ISDIR(inode->i_mode) &&
629 	       (attr->ia_mode != inode->i_mode)) ||
630 	      (attr->ia_mode & ~HFS_VALID_MODE_BITS)))) {
631 		return hsb->s_quiet ? 0 : error;
632 	}
633 
634 	if (attr->ia_valid & ATTR_MODE) {
635 		/* Only the 'w' bits can ever change and only all together. */
636 		if (attr->ia_mode & S_IWUSR)
637 			attr->ia_mode = inode->i_mode | S_IWUGO;
638 		else
639 			attr->ia_mode = inode->i_mode & ~S_IWUGO;
640 		attr->ia_mode &= S_ISDIR(inode->i_mode) ? ~hsb->s_dir_umask: ~hsb->s_file_umask;
641 	}
642 
643 	if ((attr->ia_valid & ATTR_SIZE) &&
644 	    attr->ia_size != i_size_read(inode)) {
645 		inode_dio_wait(inode);
646 
647 		error = inode_newsize_ok(inode, attr->ia_size);
648 		if (error)
649 			return error;
650 
651 		truncate_setsize(inode, attr->ia_size);
652 		hfs_file_truncate(inode);
653 		simple_inode_init_ts(inode);
654 	}
655 
656 	setattr_copy(&nop_mnt_idmap, inode, attr);
657 	mark_inode_dirty(inode);
658 	return 0;
659 }
660 
661 static int hfs_file_fsync(struct file *filp, loff_t start, loff_t end,
662 			  int datasync)
663 {
664 	struct inode *inode = filp->f_mapping->host;
665 	struct super_block * sb;
666 	int ret, err;
667 
668 	ret = file_write_and_wait_range(filp, start, end);
669 	if (ret)
670 		return ret;
671 	inode_lock(inode);
672 
673 	/* sync the inode to buffers */
674 	ret = write_inode_now(inode, 0);
675 
676 	/* sync the superblock to buffers */
677 	sb = inode->i_sb;
678 	flush_delayed_work(&HFS_SB(sb)->mdb_work);
679 	/* .. finally sync the buffers to disk */
680 	err = sync_blockdev(sb->s_bdev);
681 	if (!ret)
682 		ret = err;
683 	inode_unlock(inode);
684 	return ret;
685 }
686 
687 static const struct file_operations hfs_file_operations = {
688 	.llseek		= generic_file_llseek,
689 	.read_iter	= generic_file_read_iter,
690 	.write_iter	= generic_file_write_iter,
691 	.mmap		= generic_file_mmap,
692 	.splice_read	= filemap_splice_read,
693 	.fsync		= hfs_file_fsync,
694 	.open		= hfs_file_open,
695 	.release	= hfs_file_release,
696 };
697 
698 static const struct inode_operations hfs_file_inode_operations = {
699 	.lookup		= hfs_file_lookup,
700 	.setattr	= hfs_inode_setattr,
701 	.listxattr	= generic_listxattr,
702 };
703