xref: /openbmc/linux/fs/hfs/inode.c (revision f7777dcc)
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/aio.h>
18 
19 #include "hfs_fs.h"
20 #include "btree.h"
21 
22 static const struct file_operations hfs_file_operations;
23 static const struct inode_operations hfs_file_inode_operations;
24 
25 /*================ Variable-like macros ================*/
26 
27 #define HFS_VALID_MODE_BITS  (S_IFREG | S_IFDIR | S_IRWXUGO)
28 
29 static int hfs_writepage(struct page *page, struct writeback_control *wbc)
30 {
31 	return block_write_full_page(page, hfs_get_block, wbc);
32 }
33 
34 static int hfs_readpage(struct file *file, struct page *page)
35 {
36 	return block_read_full_page(page, hfs_get_block);
37 }
38 
39 static void hfs_write_failed(struct address_space *mapping, loff_t to)
40 {
41 	struct inode *inode = mapping->host;
42 
43 	if (to > inode->i_size) {
44 		truncate_pagecache(inode, inode->i_size);
45 		hfs_file_truncate(inode);
46 	}
47 }
48 
49 static int hfs_write_begin(struct file *file, struct address_space *mapping,
50 			loff_t pos, unsigned len, unsigned flags,
51 			struct page **pagep, void **fsdata)
52 {
53 	int ret;
54 
55 	*pagep = NULL;
56 	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
57 				hfs_get_block,
58 				&HFS_I(mapping->host)->phys_size);
59 	if (unlikely(ret))
60 		hfs_write_failed(mapping, pos + len);
61 
62 	return ret;
63 }
64 
65 static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
66 {
67 	return generic_block_bmap(mapping, block, hfs_get_block);
68 }
69 
70 static int hfs_releasepage(struct page *page, gfp_t mask)
71 {
72 	struct inode *inode = page->mapping->host;
73 	struct super_block *sb = inode->i_sb;
74 	struct hfs_btree *tree;
75 	struct hfs_bnode *node;
76 	u32 nidx;
77 	int i, res = 1;
78 
79 	switch (inode->i_ino) {
80 	case HFS_EXT_CNID:
81 		tree = HFS_SB(sb)->ext_tree;
82 		break;
83 	case HFS_CAT_CNID:
84 		tree = HFS_SB(sb)->cat_tree;
85 		break;
86 	default:
87 		BUG();
88 		return 0;
89 	}
90 
91 	if (!tree)
92 		return 0;
93 
94 	if (tree->node_size >= PAGE_CACHE_SIZE) {
95 		nidx = page->index >> (tree->node_size_shift - PAGE_CACHE_SHIFT);
96 		spin_lock(&tree->hash_lock);
97 		node = hfs_bnode_findhash(tree, nidx);
98 		if (!node)
99 			;
100 		else if (atomic_read(&node->refcnt))
101 			res = 0;
102 		if (res && node) {
103 			hfs_bnode_unhash(node);
104 			hfs_bnode_free(node);
105 		}
106 		spin_unlock(&tree->hash_lock);
107 	} else {
108 		nidx = page->index << (PAGE_CACHE_SHIFT - tree->node_size_shift);
109 		i = 1 << (PAGE_CACHE_SHIFT - tree->node_size_shift);
110 		spin_lock(&tree->hash_lock);
111 		do {
112 			node = hfs_bnode_findhash(tree, nidx++);
113 			if (!node)
114 				continue;
115 			if (atomic_read(&node->refcnt)) {
116 				res = 0;
117 				break;
118 			}
119 			hfs_bnode_unhash(node);
120 			hfs_bnode_free(node);
121 		} while (--i && nidx < tree->node_count);
122 		spin_unlock(&tree->hash_lock);
123 	}
124 	return res ? try_to_free_buffers(page) : 0;
125 }
126 
127 static ssize_t hfs_direct_IO(int rw, struct kiocb *iocb,
128 		const struct iovec *iov, loff_t offset, unsigned long nr_segs)
129 {
130 	struct file *file = iocb->ki_filp;
131 	struct address_space *mapping = file->f_mapping;
132 	struct inode *inode = file_inode(file)->i_mapping->host;
133 	ssize_t ret;
134 
135 	ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
136 				 hfs_get_block);
137 
138 	/*
139 	 * In case of error extending write may have instantiated a few
140 	 * blocks outside i_size. Trim these off again.
141 	 */
142 	if (unlikely((rw & WRITE) && ret < 0)) {
143 		loff_t isize = i_size_read(inode);
144 		loff_t end = offset + iov_length(iov, nr_segs);
145 
146 		if (end > isize)
147 			hfs_write_failed(mapping, end);
148 	}
149 
150 	return ret;
151 }
152 
153 static int hfs_writepages(struct address_space *mapping,
154 			  struct writeback_control *wbc)
155 {
156 	return mpage_writepages(mapping, wbc, hfs_get_block);
157 }
158 
159 const struct address_space_operations hfs_btree_aops = {
160 	.readpage	= hfs_readpage,
161 	.writepage	= hfs_writepage,
162 	.write_begin	= hfs_write_begin,
163 	.write_end	= generic_write_end,
164 	.bmap		= hfs_bmap,
165 	.releasepage	= hfs_releasepage,
166 };
167 
168 const struct address_space_operations hfs_aops = {
169 	.readpage	= hfs_readpage,
170 	.writepage	= hfs_writepage,
171 	.write_begin	= hfs_write_begin,
172 	.write_end	= generic_write_end,
173 	.bmap		= hfs_bmap,
174 	.direct_IO	= hfs_direct_IO,
175 	.writepages	= hfs_writepages,
176 };
177 
178 /*
179  * hfs_new_inode
180  */
181 struct inode *hfs_new_inode(struct inode *dir, struct qstr *name, umode_t mode)
182 {
183 	struct super_block *sb = dir->i_sb;
184 	struct inode *inode = new_inode(sb);
185 	if (!inode)
186 		return NULL;
187 
188 	mutex_init(&HFS_I(inode)->extents_lock);
189 	INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
190 	hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, name);
191 	inode->i_ino = HFS_SB(sb)->next_id++;
192 	inode->i_mode = mode;
193 	inode->i_uid = current_fsuid();
194 	inode->i_gid = current_fsgid();
195 	set_nlink(inode, 1);
196 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
197 	HFS_I(inode)->flags = 0;
198 	HFS_I(inode)->rsrc_inode = NULL;
199 	HFS_I(inode)->fs_blocks = 0;
200 	if (S_ISDIR(mode)) {
201 		inode->i_size = 2;
202 		HFS_SB(sb)->folder_count++;
203 		if (dir->i_ino == HFS_ROOT_CNID)
204 			HFS_SB(sb)->root_dirs++;
205 		inode->i_op = &hfs_dir_inode_operations;
206 		inode->i_fop = &hfs_dir_operations;
207 		inode->i_mode |= S_IRWXUGO;
208 		inode->i_mode &= ~HFS_SB(inode->i_sb)->s_dir_umask;
209 	} else if (S_ISREG(mode)) {
210 		HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
211 		HFS_SB(sb)->file_count++;
212 		if (dir->i_ino == HFS_ROOT_CNID)
213 			HFS_SB(sb)->root_files++;
214 		inode->i_op = &hfs_file_inode_operations;
215 		inode->i_fop = &hfs_file_operations;
216 		inode->i_mapping->a_ops = &hfs_aops;
217 		inode->i_mode |= S_IRUGO|S_IXUGO;
218 		if (mode & S_IWUSR)
219 			inode->i_mode |= S_IWUGO;
220 		inode->i_mode &= ~HFS_SB(inode->i_sb)->s_file_umask;
221 		HFS_I(inode)->phys_size = 0;
222 		HFS_I(inode)->alloc_blocks = 0;
223 		HFS_I(inode)->first_blocks = 0;
224 		HFS_I(inode)->cached_start = 0;
225 		HFS_I(inode)->cached_blocks = 0;
226 		memset(HFS_I(inode)->first_extents, 0, sizeof(hfs_extent_rec));
227 		memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
228 	}
229 	insert_inode_hash(inode);
230 	mark_inode_dirty(inode);
231 	set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
232 	hfs_mark_mdb_dirty(sb);
233 
234 	return inode;
235 }
236 
237 void hfs_delete_inode(struct inode *inode)
238 {
239 	struct super_block *sb = inode->i_sb;
240 
241 	hfs_dbg(INODE, "delete_inode: %lu\n", inode->i_ino);
242 	if (S_ISDIR(inode->i_mode)) {
243 		HFS_SB(sb)->folder_count--;
244 		if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
245 			HFS_SB(sb)->root_dirs--;
246 		set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
247 		hfs_mark_mdb_dirty(sb);
248 		return;
249 	}
250 	HFS_SB(sb)->file_count--;
251 	if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
252 		HFS_SB(sb)->root_files--;
253 	if (S_ISREG(inode->i_mode)) {
254 		if (!inode->i_nlink) {
255 			inode->i_size = 0;
256 			hfs_file_truncate(inode);
257 		}
258 	}
259 	set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
260 	hfs_mark_mdb_dirty(sb);
261 }
262 
263 void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
264 			 __be32 __log_size, __be32 phys_size, u32 clump_size)
265 {
266 	struct super_block *sb = inode->i_sb;
267 	u32 log_size = be32_to_cpu(__log_size);
268 	u16 count;
269 	int i;
270 
271 	memcpy(HFS_I(inode)->first_extents, ext, sizeof(hfs_extent_rec));
272 	for (count = 0, i = 0; i < 3; i++)
273 		count += be16_to_cpu(ext[i].count);
274 	HFS_I(inode)->first_blocks = count;
275 
276 	inode->i_size = HFS_I(inode)->phys_size = log_size;
277 	HFS_I(inode)->fs_blocks = (log_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
278 	inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
279 	HFS_I(inode)->alloc_blocks = be32_to_cpu(phys_size) /
280 				     HFS_SB(sb)->alloc_blksz;
281 	HFS_I(inode)->clump_blocks = clump_size / HFS_SB(sb)->alloc_blksz;
282 	if (!HFS_I(inode)->clump_blocks)
283 		HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
284 }
285 
286 struct hfs_iget_data {
287 	struct hfs_cat_key *key;
288 	hfs_cat_rec *rec;
289 };
290 
291 static int hfs_test_inode(struct inode *inode, void *data)
292 {
293 	struct hfs_iget_data *idata = data;
294 	hfs_cat_rec *rec;
295 
296 	rec = idata->rec;
297 	switch (rec->type) {
298 	case HFS_CDR_DIR:
299 		return inode->i_ino == be32_to_cpu(rec->dir.DirID);
300 	case HFS_CDR_FIL:
301 		return inode->i_ino == be32_to_cpu(rec->file.FlNum);
302 	default:
303 		BUG();
304 		return 1;
305 	}
306 }
307 
308 /*
309  * hfs_read_inode
310  */
311 static int hfs_read_inode(struct inode *inode, void *data)
312 {
313 	struct hfs_iget_data *idata = data;
314 	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
315 	hfs_cat_rec *rec;
316 
317 	HFS_I(inode)->flags = 0;
318 	HFS_I(inode)->rsrc_inode = NULL;
319 	mutex_init(&HFS_I(inode)->extents_lock);
320 	INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
321 
322 	/* Initialize the inode */
323 	inode->i_uid = hsb->s_uid;
324 	inode->i_gid = hsb->s_gid;
325 	set_nlink(inode, 1);
326 
327 	if (idata->key)
328 		HFS_I(inode)->cat_key = *idata->key;
329 	else
330 		HFS_I(inode)->flags |= HFS_FLG_RSRC;
331 	HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
332 
333 	rec = idata->rec;
334 	switch (rec->type) {
335 	case HFS_CDR_FIL:
336 		if (!HFS_IS_RSRC(inode)) {
337 			hfs_inode_read_fork(inode, rec->file.ExtRec, rec->file.LgLen,
338 					    rec->file.PyLen, be16_to_cpu(rec->file.ClpSize));
339 		} else {
340 			hfs_inode_read_fork(inode, rec->file.RExtRec, rec->file.RLgLen,
341 					    rec->file.RPyLen, be16_to_cpu(rec->file.ClpSize));
342 		}
343 
344 		inode->i_ino = be32_to_cpu(rec->file.FlNum);
345 		inode->i_mode = S_IRUGO | S_IXUGO;
346 		if (!(rec->file.Flags & HFS_FIL_LOCK))
347 			inode->i_mode |= S_IWUGO;
348 		inode->i_mode &= ~hsb->s_file_umask;
349 		inode->i_mode |= S_IFREG;
350 		inode->i_ctime = inode->i_atime = inode->i_mtime =
351 				hfs_m_to_utime(rec->file.MdDat);
352 		inode->i_op = &hfs_file_inode_operations;
353 		inode->i_fop = &hfs_file_operations;
354 		inode->i_mapping->a_ops = &hfs_aops;
355 		break;
356 	case HFS_CDR_DIR:
357 		inode->i_ino = be32_to_cpu(rec->dir.DirID);
358 		inode->i_size = be16_to_cpu(rec->dir.Val) + 2;
359 		HFS_I(inode)->fs_blocks = 0;
360 		inode->i_mode = S_IFDIR | (S_IRWXUGO & ~hsb->s_dir_umask);
361 		inode->i_ctime = inode->i_atime = inode->i_mtime =
362 				hfs_m_to_utime(rec->dir.MdDat);
363 		inode->i_op = &hfs_dir_inode_operations;
364 		inode->i_fop = &hfs_dir_operations;
365 		break;
366 	default:
367 		make_bad_inode(inode);
368 	}
369 	return 0;
370 }
371 
372 /*
373  * __hfs_iget()
374  *
375  * Given the MDB for a HFS filesystem, a 'key' and an 'entry' in
376  * the catalog B-tree and the 'type' of the desired file return the
377  * inode for that file/directory or NULL.  Note that 'type' indicates
378  * whether we want the actual file or directory, or the corresponding
379  * metadata (AppleDouble header file or CAP metadata file).
380  */
381 struct inode *hfs_iget(struct super_block *sb, struct hfs_cat_key *key, hfs_cat_rec *rec)
382 {
383 	struct hfs_iget_data data = { key, rec };
384 	struct inode *inode;
385 	u32 cnid;
386 
387 	switch (rec->type) {
388 	case HFS_CDR_DIR:
389 		cnid = be32_to_cpu(rec->dir.DirID);
390 		break;
391 	case HFS_CDR_FIL:
392 		cnid = be32_to_cpu(rec->file.FlNum);
393 		break;
394 	default:
395 		return NULL;
396 	}
397 	inode = iget5_locked(sb, cnid, hfs_test_inode, hfs_read_inode, &data);
398 	if (inode && (inode->i_state & I_NEW))
399 		unlock_new_inode(inode);
400 	return inode;
401 }
402 
403 void hfs_inode_write_fork(struct inode *inode, struct hfs_extent *ext,
404 			  __be32 *log_size, __be32 *phys_size)
405 {
406 	memcpy(ext, HFS_I(inode)->first_extents, sizeof(hfs_extent_rec));
407 
408 	if (log_size)
409 		*log_size = cpu_to_be32(inode->i_size);
410 	if (phys_size)
411 		*phys_size = cpu_to_be32(HFS_I(inode)->alloc_blocks *
412 					 HFS_SB(inode->i_sb)->alloc_blksz);
413 }
414 
415 int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
416 {
417 	struct inode *main_inode = inode;
418 	struct hfs_find_data fd;
419 	hfs_cat_rec rec;
420 	int res;
421 
422 	hfs_dbg(INODE, "hfs_write_inode: %lu\n", inode->i_ino);
423 	res = hfs_ext_write_extent(inode);
424 	if (res)
425 		return res;
426 
427 	if (inode->i_ino < HFS_FIRSTUSER_CNID) {
428 		switch (inode->i_ino) {
429 		case HFS_ROOT_CNID:
430 			break;
431 		case HFS_EXT_CNID:
432 			hfs_btree_write(HFS_SB(inode->i_sb)->ext_tree);
433 			return 0;
434 		case HFS_CAT_CNID:
435 			hfs_btree_write(HFS_SB(inode->i_sb)->cat_tree);
436 			return 0;
437 		default:
438 			BUG();
439 			return -EIO;
440 		}
441 	}
442 
443 	if (HFS_IS_RSRC(inode))
444 		main_inode = HFS_I(inode)->rsrc_inode;
445 
446 	if (!main_inode->i_nlink)
447 		return 0;
448 
449 	if (hfs_find_init(HFS_SB(main_inode->i_sb)->cat_tree, &fd))
450 		/* panic? */
451 		return -EIO;
452 
453 	fd.search_key->cat = HFS_I(main_inode)->cat_key;
454 	if (hfs_brec_find(&fd))
455 		/* panic? */
456 		goto out;
457 
458 	if (S_ISDIR(main_inode->i_mode)) {
459 		if (fd.entrylength < sizeof(struct hfs_cat_dir))
460 			/* panic? */;
461 		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
462 			   sizeof(struct hfs_cat_dir));
463 		if (rec.type != HFS_CDR_DIR ||
464 		    be32_to_cpu(rec.dir.DirID) != inode->i_ino) {
465 		}
466 
467 		rec.dir.MdDat = hfs_u_to_mtime(inode->i_mtime);
468 		rec.dir.Val = cpu_to_be16(inode->i_size - 2);
469 
470 		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
471 			    sizeof(struct hfs_cat_dir));
472 	} else if (HFS_IS_RSRC(inode)) {
473 		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
474 			       sizeof(struct hfs_cat_file));
475 		hfs_inode_write_fork(inode, rec.file.RExtRec,
476 				     &rec.file.RLgLen, &rec.file.RPyLen);
477 		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
478 				sizeof(struct hfs_cat_file));
479 	} else {
480 		if (fd.entrylength < sizeof(struct hfs_cat_file))
481 			/* panic? */;
482 		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
483 			   sizeof(struct hfs_cat_file));
484 		if (rec.type != HFS_CDR_FIL ||
485 		    be32_to_cpu(rec.file.FlNum) != inode->i_ino) {
486 		}
487 
488 		if (inode->i_mode & S_IWUSR)
489 			rec.file.Flags &= ~HFS_FIL_LOCK;
490 		else
491 			rec.file.Flags |= HFS_FIL_LOCK;
492 		hfs_inode_write_fork(inode, rec.file.ExtRec, &rec.file.LgLen, &rec.file.PyLen);
493 		rec.file.MdDat = hfs_u_to_mtime(inode->i_mtime);
494 
495 		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
496 			    sizeof(struct hfs_cat_file));
497 	}
498 out:
499 	hfs_find_exit(&fd);
500 	return 0;
501 }
502 
503 static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
504 				      unsigned int flags)
505 {
506 	struct inode *inode = NULL;
507 	hfs_cat_rec rec;
508 	struct hfs_find_data fd;
509 	int res;
510 
511 	if (HFS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc"))
512 		goto out;
513 
514 	inode = HFS_I(dir)->rsrc_inode;
515 	if (inode)
516 		goto out;
517 
518 	inode = new_inode(dir->i_sb);
519 	if (!inode)
520 		return ERR_PTR(-ENOMEM);
521 
522 	res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
523 	if (res) {
524 		iput(inode);
525 		return ERR_PTR(res);
526 	}
527 	fd.search_key->cat = HFS_I(dir)->cat_key;
528 	res = hfs_brec_read(&fd, &rec, sizeof(rec));
529 	if (!res) {
530 		struct hfs_iget_data idata = { NULL, &rec };
531 		hfs_read_inode(inode, &idata);
532 	}
533 	hfs_find_exit(&fd);
534 	if (res) {
535 		iput(inode);
536 		return ERR_PTR(res);
537 	}
538 	HFS_I(inode)->rsrc_inode = dir;
539 	HFS_I(dir)->rsrc_inode = inode;
540 	igrab(dir);
541 	hlist_add_fake(&inode->i_hash);
542 	mark_inode_dirty(inode);
543 out:
544 	d_add(dentry, inode);
545 	return NULL;
546 }
547 
548 void hfs_evict_inode(struct inode *inode)
549 {
550 	truncate_inode_pages(&inode->i_data, 0);
551 	clear_inode(inode);
552 	if (HFS_IS_RSRC(inode) && HFS_I(inode)->rsrc_inode) {
553 		HFS_I(HFS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
554 		iput(HFS_I(inode)->rsrc_inode);
555 	}
556 }
557 
558 static int hfs_file_open(struct inode *inode, struct file *file)
559 {
560 	if (HFS_IS_RSRC(inode))
561 		inode = HFS_I(inode)->rsrc_inode;
562 	atomic_inc(&HFS_I(inode)->opencnt);
563 	return 0;
564 }
565 
566 static int hfs_file_release(struct inode *inode, struct file *file)
567 {
568 	//struct super_block *sb = inode->i_sb;
569 
570 	if (HFS_IS_RSRC(inode))
571 		inode = HFS_I(inode)->rsrc_inode;
572 	if (atomic_dec_and_test(&HFS_I(inode)->opencnt)) {
573 		mutex_lock(&inode->i_mutex);
574 		hfs_file_truncate(inode);
575 		//if (inode->i_flags & S_DEAD) {
576 		//	hfs_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
577 		//	hfs_delete_inode(inode);
578 		//}
579 		mutex_unlock(&inode->i_mutex);
580 	}
581 	return 0;
582 }
583 
584 /*
585  * hfs_notify_change()
586  *
587  * Based very closely on fs/msdos/inode.c by Werner Almesberger
588  *
589  * This is the notify_change() field in the super_operations structure
590  * for HFS file systems.  The purpose is to take that changes made to
591  * an inode and apply then in a filesystem-dependent manner.  In this
592  * case the process has a few of tasks to do:
593  *  1) prevent changes to the i_uid and i_gid fields.
594  *  2) map file permissions to the closest allowable permissions
595  *  3) Since multiple Linux files can share the same on-disk inode under
596  *     HFS (for instance the data and resource forks of a file) a change
597  *     to permissions must be applied to all other in-core inodes which
598  *     correspond to the same HFS file.
599  */
600 
601 int hfs_inode_setattr(struct dentry *dentry, struct iattr * attr)
602 {
603 	struct inode *inode = dentry->d_inode;
604 	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
605 	int error;
606 
607 	error = inode_change_ok(inode, attr); /* basic permission checks */
608 	if (error)
609 		return error;
610 
611 	/* no uig/gid changes and limit which mode bits can be set */
612 	if (((attr->ia_valid & ATTR_UID) &&
613 	     (!uid_eq(attr->ia_uid, hsb->s_uid))) ||
614 	    ((attr->ia_valid & ATTR_GID) &&
615 	     (!gid_eq(attr->ia_gid, hsb->s_gid))) ||
616 	    ((attr->ia_valid & ATTR_MODE) &&
617 	     ((S_ISDIR(inode->i_mode) &&
618 	       (attr->ia_mode != inode->i_mode)) ||
619 	      (attr->ia_mode & ~HFS_VALID_MODE_BITS)))) {
620 		return hsb->s_quiet ? 0 : error;
621 	}
622 
623 	if (attr->ia_valid & ATTR_MODE) {
624 		/* Only the 'w' bits can ever change and only all together. */
625 		if (attr->ia_mode & S_IWUSR)
626 			attr->ia_mode = inode->i_mode | S_IWUGO;
627 		else
628 			attr->ia_mode = inode->i_mode & ~S_IWUGO;
629 		attr->ia_mode &= S_ISDIR(inode->i_mode) ? ~hsb->s_dir_umask: ~hsb->s_file_umask;
630 	}
631 
632 	if ((attr->ia_valid & ATTR_SIZE) &&
633 	    attr->ia_size != i_size_read(inode)) {
634 		inode_dio_wait(inode);
635 
636 		error = inode_newsize_ok(inode, attr->ia_size);
637 		if (error)
638 			return error;
639 
640 		truncate_setsize(inode, attr->ia_size);
641 		hfs_file_truncate(inode);
642 	}
643 
644 	setattr_copy(inode, attr);
645 	mark_inode_dirty(inode);
646 	return 0;
647 }
648 
649 static int hfs_file_fsync(struct file *filp, loff_t start, loff_t end,
650 			  int datasync)
651 {
652 	struct inode *inode = filp->f_mapping->host;
653 	struct super_block * sb;
654 	int ret, err;
655 
656 	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
657 	if (ret)
658 		return ret;
659 	mutex_lock(&inode->i_mutex);
660 
661 	/* sync the inode to buffers */
662 	ret = write_inode_now(inode, 0);
663 
664 	/* sync the superblock to buffers */
665 	sb = inode->i_sb;
666 	flush_delayed_work(&HFS_SB(sb)->mdb_work);
667 	/* .. finally sync the buffers to disk */
668 	err = sync_blockdev(sb->s_bdev);
669 	if (!ret)
670 		ret = err;
671 	mutex_unlock(&inode->i_mutex);
672 	return ret;
673 }
674 
675 static const struct file_operations hfs_file_operations = {
676 	.llseek		= generic_file_llseek,
677 	.read		= do_sync_read,
678 	.aio_read	= generic_file_aio_read,
679 	.write		= do_sync_write,
680 	.aio_write	= generic_file_aio_write,
681 	.mmap		= generic_file_mmap,
682 	.splice_read	= generic_file_splice_read,
683 	.fsync		= hfs_file_fsync,
684 	.open		= hfs_file_open,
685 	.release	= hfs_file_release,
686 };
687 
688 static const struct inode_operations hfs_file_inode_operations = {
689 	.lookup		= hfs_file_lookup,
690 	.setattr	= hfs_inode_setattr,
691 	.setxattr	= hfs_setxattr,
692 	.getxattr	= hfs_getxattr,
693 	.listxattr	= hfs_listxattr,
694 };
695