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1/*
2 * linux/fs/minix/dir.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * minix directory handling functions
7 *
8 * Updated to filesystem version 3 by Daniel Aragones
9 */
10
11#include "minix.h"
12#include <linux/buffer_head.h>
13#include <linux/highmem.h>
14#include <linux/swap.h>
15
16typedef struct minix_dir_entry minix_dirent;
17typedef struct minix3_dir_entry minix3_dirent;
18
19static int minix_readdir(struct file *, struct dir_context *);
20
21const struct file_operations minix_dir_operations = {
22 .llseek = generic_file_llseek,
23 .read = generic_read_dir,
24 .iterate = minix_readdir,
25 .fsync = generic_file_fsync,
26};
27
28static inline void dir_put_page(struct page *page)
29{
30 kunmap(page);
31 put_page(page);
32}
33
34/*
35 * Return the offset into page `page_nr' of the last valid
36 * byte in that page, plus one.
37 */
38static unsigned
39minix_last_byte(struct inode *inode, unsigned long page_nr)
40{
41 unsigned last_byte = PAGE_SIZE;
42
43 if (page_nr == (inode->i_size >> PAGE_SHIFT))
44 last_byte = inode->i_size & (PAGE_SIZE - 1);
45 return last_byte;
46}
47
48static int dir_commit_chunk(struct page *page, loff_t pos, unsigned len)
49{
50 struct address_space *mapping = page->mapping;
51 struct inode *dir = mapping->host;
52 int err = 0;
53 block_write_end(NULL, mapping, pos, len, len, page, NULL);
54
55 if (pos+len > dir->i_size) {
56 i_size_write(dir, pos+len);
57 mark_inode_dirty(dir);
58 }
59 if (IS_DIRSYNC(dir))
60 err = write_one_page(page, 1);
61 else
62 unlock_page(page);
63 return err;
64}
65
66static struct page * dir_get_page(struct inode *dir, unsigned long n)
67{
68 struct address_space *mapping = dir->i_mapping;
69 struct page *page = read_mapping_page(mapping, n, NULL);
70 if (!IS_ERR(page))
71 kmap(page);
72 return page;
73}
74
75static inline void *minix_next_entry(void *de, struct minix_sb_info *sbi)
76{
77 return (void*)((char*)de + sbi->s_dirsize);
78}
79
80static int minix_readdir(struct file *file, struct dir_context *ctx)
81{
82 struct inode *inode = file_inode(file);
83 struct super_block *sb = inode->i_sb;
84 struct minix_sb_info *sbi = minix_sb(sb);
85 unsigned chunk_size = sbi->s_dirsize;
86 unsigned long npages = dir_pages(inode);
87 unsigned long pos = ctx->pos;
88 unsigned offset;
89 unsigned long n;
90
91 ctx->pos = pos = ALIGN(pos, chunk_size);
92 if (pos >= inode->i_size)
93 return 0;
94
95 offset = pos & ~PAGE_MASK;
96 n = pos >> PAGE_SHIFT;
97
98 for ( ; n < npages; n++, offset = 0) {
99 char *p, *kaddr, *limit;
100 struct page *page = dir_get_page(inode, n);
101
102 if (IS_ERR(page))
103 continue;
104 kaddr = (char *)page_address(page);
105 p = kaddr+offset;
106 limit = kaddr + minix_last_byte(inode, n) - chunk_size;
107 for ( ; p <= limit; p = minix_next_entry(p, sbi)) {
108 const char *name;
109 __u32 inumber;
110 if (sbi->s_version == MINIX_V3) {
111 minix3_dirent *de3 = (minix3_dirent *)p;
112 name = de3->name;
113 inumber = de3->inode;
114 } else {
115 minix_dirent *de = (minix_dirent *)p;
116 name = de->name;
117 inumber = de->inode;
118 }
119 if (inumber) {
120 unsigned l = strnlen(name, sbi->s_namelen);
121 if (!dir_emit(ctx, name, l,
122 inumber, DT_UNKNOWN)) {
123 dir_put_page(page);
124 return 0;
125 }
126 }
127 ctx->pos += chunk_size;
128 }
129 dir_put_page(page);
130 }
131 return 0;
132}
133
134static inline int namecompare(int len, int maxlen,
135 const char * name, const char * buffer)
136{
137 if (len < maxlen && buffer[len])
138 return 0;
139 return !memcmp(name, buffer, len);
140}
141
142/*
143 * minix_find_entry()
144 *
145 * finds an entry in the specified directory with the wanted name. It
146 * returns the cache buffer in which the entry was found, and the entry
147 * itself (as a parameter - res_dir). It does NOT read the inode of the
148 * entry - you'll have to do that yourself if you want to.
149 */
150minix_dirent *minix_find_entry(struct dentry *dentry, struct page **res_page)
151{
152 const char * name = dentry->d_name.name;
153 int namelen = dentry->d_name.len;
154 struct inode * dir = d_inode(dentry->d_parent);
155 struct super_block * sb = dir->i_sb;
156 struct minix_sb_info * sbi = minix_sb(sb);
157 unsigned long n;
158 unsigned long npages = dir_pages(dir);
159 struct page *page = NULL;
160 char *p;
161
162 char *namx;
163 __u32 inumber;
164 *res_page = NULL;
165
166 for (n = 0; n < npages; n++) {
167 char *kaddr, *limit;
168
169 page = dir_get_page(dir, n);
170 if (IS_ERR(page))
171 continue;
172
173 kaddr = (char*)page_address(page);
174 limit = kaddr + minix_last_byte(dir, n) - sbi->s_dirsize;
175 for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
176 if (sbi->s_version == MINIX_V3) {
177 minix3_dirent *de3 = (minix3_dirent *)p;
178 namx = de3->name;
179 inumber = de3->inode;
180 } else {
181 minix_dirent *de = (minix_dirent *)p;
182 namx = de->name;
183 inumber = de->inode;
184 }
185 if (!inumber)
186 continue;
187 if (namecompare(namelen, sbi->s_namelen, name, namx))
188 goto found;
189 }
190 dir_put_page(page);
191 }
192 return NULL;
193
194found:
195 *res_page = page;
196 return (minix_dirent *)p;
197}
198
199int minix_add_link(struct dentry *dentry, struct inode *inode)
200{
201 struct inode *dir = d_inode(dentry->d_parent);
202 const char * name = dentry->d_name.name;
203 int namelen = dentry->d_name.len;
204 struct super_block * sb = dir->i_sb;
205 struct minix_sb_info * sbi = minix_sb(sb);
206 struct page *page = NULL;
207 unsigned long npages = dir_pages(dir);
208 unsigned long n;
209 char *kaddr, *p;
210 minix_dirent *de;
211 minix3_dirent *de3;
212 loff_t pos;
213 int err;
214 char *namx = NULL;
215 __u32 inumber;
216
217 /*
218 * We take care of directory expansion in the same loop
219 * This code plays outside i_size, so it locks the page
220 * to protect that region.
221 */
222 for (n = 0; n <= npages; n++) {
223 char *limit, *dir_end;
224
225 page = dir_get_page(dir, n);
226 err = PTR_ERR(page);
227 if (IS_ERR(page))
228 goto out;
229 lock_page(page);
230 kaddr = (char*)page_address(page);
231 dir_end = kaddr + minix_last_byte(dir, n);
232 limit = kaddr + PAGE_SIZE - sbi->s_dirsize;
233 for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
234 de = (minix_dirent *)p;
235 de3 = (minix3_dirent *)p;
236 if (sbi->s_version == MINIX_V3) {
237 namx = de3->name;
238 inumber = de3->inode;
239 } else {
240 namx = de->name;
241 inumber = de->inode;
242 }
243 if (p == dir_end) {
244 /* We hit i_size */
245 if (sbi->s_version == MINIX_V3)
246 de3->inode = 0;
247 else
248 de->inode = 0;
249 goto got_it;
250 }
251 if (!inumber)
252 goto got_it;
253 err = -EEXIST;
254 if (namecompare(namelen, sbi->s_namelen, name, namx))
255 goto out_unlock;
256 }
257 unlock_page(page);
258 dir_put_page(page);
259 }
260 BUG();
261 return -EINVAL;
262
263got_it:
264 pos = page_offset(page) + p - (char *)page_address(page);
265 err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
266 if (err)
267 goto out_unlock;
268 memcpy (namx, name, namelen);
269 if (sbi->s_version == MINIX_V3) {
270 memset (namx + namelen, 0, sbi->s_dirsize - namelen - 4);
271 de3->inode = inode->i_ino;
272 } else {
273 memset (namx + namelen, 0, sbi->s_dirsize - namelen - 2);
274 de->inode = inode->i_ino;
275 }
276 err = dir_commit_chunk(page, pos, sbi->s_dirsize);
277 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
278 mark_inode_dirty(dir);
279out_put:
280 dir_put_page(page);
281out:
282 return err;
283out_unlock:
284 unlock_page(page);
285 goto out_put;
286}
287
288int minix_delete_entry(struct minix_dir_entry *de, struct page *page)
289{
290 struct inode *inode = page->mapping->host;
291 char *kaddr = page_address(page);
292 loff_t pos = page_offset(page) + (char*)de - kaddr;
293 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
294 unsigned len = sbi->s_dirsize;
295 int err;
296
297 lock_page(page);
298 err = minix_prepare_chunk(page, pos, len);
299 if (err == 0) {
300 if (sbi->s_version == MINIX_V3)
301 ((minix3_dirent *) de)->inode = 0;
302 else
303 de->inode = 0;
304 err = dir_commit_chunk(page, pos, len);
305 } else {
306 unlock_page(page);
307 }
308 dir_put_page(page);
309 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
310 mark_inode_dirty(inode);
311 return err;
312}
313
314int minix_make_empty(struct inode *inode, struct inode *dir)
315{
316 struct page *page = grab_cache_page(inode->i_mapping, 0);
317 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
318 char *kaddr;
319 int err;
320
321 if (!page)
322 return -ENOMEM;
323 err = minix_prepare_chunk(page, 0, 2 * sbi->s_dirsize);
324 if (err) {
325 unlock_page(page);
326 goto fail;
327 }
328
329 kaddr = kmap_atomic(page);
330 memset(kaddr, 0, PAGE_SIZE);
331
332 if (sbi->s_version == MINIX_V3) {
333 minix3_dirent *de3 = (minix3_dirent *)kaddr;
334
335 de3->inode = inode->i_ino;
336 strcpy(de3->name, ".");
337 de3 = minix_next_entry(de3, sbi);
338 de3->inode = dir->i_ino;
339 strcpy(de3->name, "..");
340 } else {
341 minix_dirent *de = (minix_dirent *)kaddr;
342
343 de->inode = inode->i_ino;
344 strcpy(de->name, ".");
345 de = minix_next_entry(de, sbi);
346 de->inode = dir->i_ino;
347 strcpy(de->name, "..");
348 }
349 kunmap_atomic(kaddr);
350
351 err = dir_commit_chunk(page, 0, 2 * sbi->s_dirsize);
352fail:
353 put_page(page);
354 return err;
355}
356
357/*
358 * routine to check that the specified directory is empty (for rmdir)
359 */
360int minix_empty_dir(struct inode * inode)
361{
362 struct page *page = NULL;
363 unsigned long i, npages = dir_pages(inode);
364 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
365 char *name;
366 __u32 inumber;
367
368 for (i = 0; i < npages; i++) {
369 char *p, *kaddr, *limit;
370
371 page = dir_get_page(inode, i);
372 if (IS_ERR(page))
373 continue;
374
375 kaddr = (char *)page_address(page);
376 limit = kaddr + minix_last_byte(inode, i) - sbi->s_dirsize;
377 for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
378 if (sbi->s_version == MINIX_V3) {
379 minix3_dirent *de3 = (minix3_dirent *)p;
380 name = de3->name;
381 inumber = de3->inode;
382 } else {
383 minix_dirent *de = (minix_dirent *)p;
384 name = de->name;
385 inumber = de->inode;
386 }
387
388 if (inumber != 0) {
389 /* check for . and .. */
390 if (name[0] != '.')
391 goto not_empty;
392 if (!name[1]) {
393 if (inumber != inode->i_ino)
394 goto not_empty;
395 } else if (name[1] != '.')
396 goto not_empty;
397 else if (name[2])
398 goto not_empty;
399 }
400 }
401 dir_put_page(page);
402 }
403 return 1;
404
405not_empty:
406 dir_put_page(page);
407 return 0;
408}
409
410/* Releases the page */
411void minix_set_link(struct minix_dir_entry *de, struct page *page,
412 struct inode *inode)
413{
414 struct inode *dir = page->mapping->host;
415 struct minix_sb_info *sbi = minix_sb(dir->i_sb);
416 loff_t pos = page_offset(page) +
417 (char *)de-(char*)page_address(page);
418 int err;
419
420 lock_page(page);
421
422 err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
423 if (err == 0) {
424 if (sbi->s_version == MINIX_V3)
425 ((minix3_dirent *) de)->inode = inode->i_ino;
426 else
427 de->inode = inode->i_ino;
428 err = dir_commit_chunk(page, pos, sbi->s_dirsize);
429 } else {
430 unlock_page(page);
431 }
432 dir_put_page(page);
433 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
434 mark_inode_dirty(dir);
435}
436
437struct minix_dir_entry * minix_dotdot (struct inode *dir, struct page **p)
438{
439 struct page *page = dir_get_page(dir, 0);
440 struct minix_sb_info *sbi = minix_sb(dir->i_sb);
441 struct minix_dir_entry *de = NULL;
442
443 if (!IS_ERR(page)) {
444 de = minix_next_entry(page_address(page), sbi);
445 *p = page;
446 }
447 return de;
448}
449
450ino_t minix_inode_by_name(struct dentry *dentry)
451{
452 struct page *page;
453 struct minix_dir_entry *de = minix_find_entry(dentry, &page);
454 ino_t res = 0;
455
456 if (de) {
457 struct address_space *mapping = page->mapping;
458 struct inode *inode = mapping->host;
459 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
460
461 if (sbi->s_version == MINIX_V3)
462 res = ((minix3_dirent *) de)->inode;
463 else
464 res = de->inode;
465 dir_put_page(page);
466 }
467 return res;
468}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/minix/dir.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 *
7 * minix directory handling functions
8 *
9 * Updated to filesystem version 3 by Daniel Aragones
10 */
11
12#include "minix.h"
13#include <linux/buffer_head.h>
14#include <linux/highmem.h>
15#include <linux/swap.h>
16
17typedef struct minix_dir_entry minix_dirent;
18typedef struct minix3_dir_entry minix3_dirent;
19
20static int minix_readdir(struct file *, struct dir_context *);
21
22const struct file_operations minix_dir_operations = {
23 .llseek = generic_file_llseek,
24 .read = generic_read_dir,
25 .iterate_shared = minix_readdir,
26 .fsync = generic_file_fsync,
27};
28
29/*
30 * Return the offset into page `page_nr' of the last valid
31 * byte in that page, plus one.
32 */
33static unsigned
34minix_last_byte(struct inode *inode, unsigned long page_nr)
35{
36 unsigned last_byte = PAGE_SIZE;
37
38 if (page_nr == (inode->i_size >> PAGE_SHIFT))
39 last_byte = inode->i_size & (PAGE_SIZE - 1);
40 return last_byte;
41}
42
43static void dir_commit_chunk(struct page *page, loff_t pos, unsigned len)
44{
45 struct address_space *mapping = page->mapping;
46 struct inode *dir = mapping->host;
47
48 block_write_end(NULL, mapping, pos, len, len, page, NULL);
49
50 if (pos+len > dir->i_size) {
51 i_size_write(dir, pos+len);
52 mark_inode_dirty(dir);
53 }
54 unlock_page(page);
55}
56
57static int minix_handle_dirsync(struct inode *dir)
58{
59 int err;
60
61 err = filemap_write_and_wait(dir->i_mapping);
62 if (!err)
63 err = sync_inode_metadata(dir, 1);
64 return err;
65}
66
67static void *dir_get_page(struct inode *dir, unsigned long n, struct page **p)
68{
69 struct address_space *mapping = dir->i_mapping;
70 struct page *page = read_mapping_page(mapping, n, NULL);
71 if (IS_ERR(page))
72 return ERR_CAST(page);
73 *p = page;
74 return kmap_local_page(page);
75}
76
77static inline void *minix_next_entry(void *de, struct minix_sb_info *sbi)
78{
79 return (void*)((char*)de + sbi->s_dirsize);
80}
81
82static int minix_readdir(struct file *file, struct dir_context *ctx)
83{
84 struct inode *inode = file_inode(file);
85 struct super_block *sb = inode->i_sb;
86 struct minix_sb_info *sbi = minix_sb(sb);
87 unsigned chunk_size = sbi->s_dirsize;
88 unsigned long npages = dir_pages(inode);
89 unsigned long pos = ctx->pos;
90 unsigned offset;
91 unsigned long n;
92
93 ctx->pos = pos = ALIGN(pos, chunk_size);
94 if (pos >= inode->i_size)
95 return 0;
96
97 offset = pos & ~PAGE_MASK;
98 n = pos >> PAGE_SHIFT;
99
100 for ( ; n < npages; n++, offset = 0) {
101 char *p, *kaddr, *limit;
102 struct page *page;
103
104 kaddr = dir_get_page(inode, n, &page);
105 if (IS_ERR(kaddr))
106 continue;
107 p = kaddr+offset;
108 limit = kaddr + minix_last_byte(inode, n) - chunk_size;
109 for ( ; p <= limit; p = minix_next_entry(p, sbi)) {
110 const char *name;
111 __u32 inumber;
112 if (sbi->s_version == MINIX_V3) {
113 minix3_dirent *de3 = (minix3_dirent *)p;
114 name = de3->name;
115 inumber = de3->inode;
116 } else {
117 minix_dirent *de = (minix_dirent *)p;
118 name = de->name;
119 inumber = de->inode;
120 }
121 if (inumber) {
122 unsigned l = strnlen(name, sbi->s_namelen);
123 if (!dir_emit(ctx, name, l,
124 inumber, DT_UNKNOWN)) {
125 unmap_and_put_page(page, p);
126 return 0;
127 }
128 }
129 ctx->pos += chunk_size;
130 }
131 unmap_and_put_page(page, kaddr);
132 }
133 return 0;
134}
135
136static inline int namecompare(int len, int maxlen,
137 const char * name, const char * buffer)
138{
139 if (len < maxlen && buffer[len])
140 return 0;
141 return !memcmp(name, buffer, len);
142}
143
144/*
145 * minix_find_entry()
146 *
147 * finds an entry in the specified directory with the wanted name. It
148 * returns the cache buffer in which the entry was found, and the entry
149 * itself (as a parameter - res_dir). It does NOT read the inode of the
150 * entry - you'll have to do that yourself if you want to.
151 */
152minix_dirent *minix_find_entry(struct dentry *dentry, struct page **res_page)
153{
154 const char * name = dentry->d_name.name;
155 int namelen = dentry->d_name.len;
156 struct inode * dir = d_inode(dentry->d_parent);
157 struct super_block * sb = dir->i_sb;
158 struct minix_sb_info * sbi = minix_sb(sb);
159 unsigned long n;
160 unsigned long npages = dir_pages(dir);
161 struct page *page = NULL;
162 char *p;
163
164 char *namx;
165 __u32 inumber;
166 *res_page = NULL;
167
168 for (n = 0; n < npages; n++) {
169 char *kaddr, *limit;
170
171 kaddr = dir_get_page(dir, n, &page);
172 if (IS_ERR(kaddr))
173 continue;
174
175 limit = kaddr + minix_last_byte(dir, n) - sbi->s_dirsize;
176 for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
177 if (sbi->s_version == MINIX_V3) {
178 minix3_dirent *de3 = (minix3_dirent *)p;
179 namx = de3->name;
180 inumber = de3->inode;
181 } else {
182 minix_dirent *de = (minix_dirent *)p;
183 namx = de->name;
184 inumber = de->inode;
185 }
186 if (!inumber)
187 continue;
188 if (namecompare(namelen, sbi->s_namelen, name, namx))
189 goto found;
190 }
191 unmap_and_put_page(page, kaddr);
192 }
193 return NULL;
194
195found:
196 *res_page = page;
197 return (minix_dirent *)p;
198}
199
200int minix_add_link(struct dentry *dentry, struct inode *inode)
201{
202 struct inode *dir = d_inode(dentry->d_parent);
203 const char * name = dentry->d_name.name;
204 int namelen = dentry->d_name.len;
205 struct super_block * sb = dir->i_sb;
206 struct minix_sb_info * sbi = minix_sb(sb);
207 struct page *page = NULL;
208 unsigned long npages = dir_pages(dir);
209 unsigned long n;
210 char *kaddr, *p;
211 minix_dirent *de;
212 minix3_dirent *de3;
213 loff_t pos;
214 int err;
215 char *namx = NULL;
216 __u32 inumber;
217
218 /*
219 * We take care of directory expansion in the same loop
220 * This code plays outside i_size, so it locks the page
221 * to protect that region.
222 */
223 for (n = 0; n <= npages; n++) {
224 char *limit, *dir_end;
225
226 kaddr = dir_get_page(dir, n, &page);
227 if (IS_ERR(kaddr))
228 return PTR_ERR(kaddr);
229 lock_page(page);
230 dir_end = kaddr + minix_last_byte(dir, n);
231 limit = kaddr + PAGE_SIZE - sbi->s_dirsize;
232 for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
233 de = (minix_dirent *)p;
234 de3 = (minix3_dirent *)p;
235 if (sbi->s_version == MINIX_V3) {
236 namx = de3->name;
237 inumber = de3->inode;
238 } else {
239 namx = de->name;
240 inumber = de->inode;
241 }
242 if (p == dir_end) {
243 /* We hit i_size */
244 if (sbi->s_version == MINIX_V3)
245 de3->inode = 0;
246 else
247 de->inode = 0;
248 goto got_it;
249 }
250 if (!inumber)
251 goto got_it;
252 err = -EEXIST;
253 if (namecompare(namelen, sbi->s_namelen, name, namx))
254 goto out_unlock;
255 }
256 unlock_page(page);
257 unmap_and_put_page(page, kaddr);
258 }
259 BUG();
260 return -EINVAL;
261
262got_it:
263 pos = page_offset(page) + offset_in_page(p);
264 err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
265 if (err)
266 goto out_unlock;
267 memcpy (namx, name, namelen);
268 if (sbi->s_version == MINIX_V3) {
269 memset (namx + namelen, 0, sbi->s_dirsize - namelen - 4);
270 de3->inode = inode->i_ino;
271 } else {
272 memset (namx + namelen, 0, sbi->s_dirsize - namelen - 2);
273 de->inode = inode->i_ino;
274 }
275 dir_commit_chunk(page, pos, sbi->s_dirsize);
276 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
277 mark_inode_dirty(dir);
278 err = minix_handle_dirsync(dir);
279out_put:
280 unmap_and_put_page(page, kaddr);
281 return err;
282out_unlock:
283 unlock_page(page);
284 goto out_put;
285}
286
287int minix_delete_entry(struct minix_dir_entry *de, struct page *page)
288{
289 struct inode *inode = page->mapping->host;
290 loff_t pos = page_offset(page) + offset_in_page(de);
291 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
292 unsigned len = sbi->s_dirsize;
293 int err;
294
295 lock_page(page);
296 err = minix_prepare_chunk(page, pos, len);
297 if (err) {
298 unlock_page(page);
299 return err;
300 }
301 if (sbi->s_version == MINIX_V3)
302 ((minix3_dirent *)de)->inode = 0;
303 else
304 de->inode = 0;
305 dir_commit_chunk(page, pos, len);
306 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
307 mark_inode_dirty(inode);
308 return minix_handle_dirsync(inode);
309}
310
311int minix_make_empty(struct inode *inode, struct inode *dir)
312{
313 struct page *page = grab_cache_page(inode->i_mapping, 0);
314 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
315 char *kaddr;
316 int err;
317
318 if (!page)
319 return -ENOMEM;
320 err = minix_prepare_chunk(page, 0, 2 * sbi->s_dirsize);
321 if (err) {
322 unlock_page(page);
323 goto fail;
324 }
325
326 kaddr = kmap_local_page(page);
327 memset(kaddr, 0, PAGE_SIZE);
328
329 if (sbi->s_version == MINIX_V3) {
330 minix3_dirent *de3 = (minix3_dirent *)kaddr;
331
332 de3->inode = inode->i_ino;
333 strcpy(de3->name, ".");
334 de3 = minix_next_entry(de3, sbi);
335 de3->inode = dir->i_ino;
336 strcpy(de3->name, "..");
337 } else {
338 minix_dirent *de = (minix_dirent *)kaddr;
339
340 de->inode = inode->i_ino;
341 strcpy(de->name, ".");
342 de = minix_next_entry(de, sbi);
343 de->inode = dir->i_ino;
344 strcpy(de->name, "..");
345 }
346 kunmap_local(kaddr);
347
348 dir_commit_chunk(page, 0, 2 * sbi->s_dirsize);
349 err = minix_handle_dirsync(inode);
350fail:
351 put_page(page);
352 return err;
353}
354
355/*
356 * routine to check that the specified directory is empty (for rmdir)
357 */
358int minix_empty_dir(struct inode * inode)
359{
360 struct page *page = NULL;
361 unsigned long i, npages = dir_pages(inode);
362 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
363 char *name, *kaddr;
364 __u32 inumber;
365
366 for (i = 0; i < npages; i++) {
367 char *p, *limit;
368
369 kaddr = dir_get_page(inode, i, &page);
370 if (IS_ERR(kaddr))
371 continue;
372
373 limit = kaddr + minix_last_byte(inode, i) - sbi->s_dirsize;
374 for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
375 if (sbi->s_version == MINIX_V3) {
376 minix3_dirent *de3 = (minix3_dirent *)p;
377 name = de3->name;
378 inumber = de3->inode;
379 } else {
380 minix_dirent *de = (minix_dirent *)p;
381 name = de->name;
382 inumber = de->inode;
383 }
384
385 if (inumber != 0) {
386 /* check for . and .. */
387 if (name[0] != '.')
388 goto not_empty;
389 if (!name[1]) {
390 if (inumber != inode->i_ino)
391 goto not_empty;
392 } else if (name[1] != '.')
393 goto not_empty;
394 else if (name[2])
395 goto not_empty;
396 }
397 }
398 unmap_and_put_page(page, kaddr);
399 }
400 return 1;
401
402not_empty:
403 unmap_and_put_page(page, kaddr);
404 return 0;
405}
406
407/* Releases the page */
408int minix_set_link(struct minix_dir_entry *de, struct page *page,
409 struct inode *inode)
410{
411 struct inode *dir = page->mapping->host;
412 struct minix_sb_info *sbi = minix_sb(dir->i_sb);
413 loff_t pos = page_offset(page) + offset_in_page(de);
414 int err;
415
416 lock_page(page);
417 err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
418 if (err) {
419 unlock_page(page);
420 return err;
421 }
422 if (sbi->s_version == MINIX_V3)
423 ((minix3_dirent *)de)->inode = inode->i_ino;
424 else
425 de->inode = inode->i_ino;
426 dir_commit_chunk(page, pos, sbi->s_dirsize);
427 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
428 mark_inode_dirty(dir);
429 return minix_handle_dirsync(dir);
430}
431
432struct minix_dir_entry * minix_dotdot (struct inode *dir, struct page **p)
433{
434 struct minix_sb_info *sbi = minix_sb(dir->i_sb);
435 struct minix_dir_entry *de = dir_get_page(dir, 0, p);
436
437 if (!IS_ERR(de))
438 return minix_next_entry(de, sbi);
439 return NULL;
440}
441
442ino_t minix_inode_by_name(struct dentry *dentry)
443{
444 struct page *page;
445 struct minix_dir_entry *de = minix_find_entry(dentry, &page);
446 ino_t res = 0;
447
448 if (de) {
449 struct address_space *mapping = page->mapping;
450 struct inode *inode = mapping->host;
451 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
452
453 if (sbi->s_version == MINIX_V3)
454 res = ((minix3_dirent *) de)->inode;
455 else
456 res = de->inode;
457 unmap_and_put_page(page, de);
458 }
459 return res;
460}