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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
29static inline void dir_put_page(struct page *page)
30{
31 kunmap(page);
32 put_page(page);
33}
34
35/*
36 * Return the offset into page `page_nr' of the last valid
37 * byte in that page, plus one.
38 */
39static unsigned
40minix_last_byte(struct inode *inode, unsigned long page_nr)
41{
42 unsigned last_byte = PAGE_SIZE;
43
44 if (page_nr == (inode->i_size >> PAGE_SHIFT))
45 last_byte = inode->i_size & (PAGE_SIZE - 1);
46 return last_byte;
47}
48
49static int dir_commit_chunk(struct page *page, loff_t pos, unsigned len)
50{
51 struct address_space *mapping = page->mapping;
52 struct inode *dir = mapping->host;
53 int err = 0;
54 block_write_end(NULL, mapping, pos, len, len, page, NULL);
55
56 if (pos+len > dir->i_size) {
57 i_size_write(dir, pos+len);
58 mark_inode_dirty(dir);
59 }
60 if (IS_DIRSYNC(dir))
61 err = write_one_page(page);
62 else
63 unlock_page(page);
64 return err;
65}
66
67static struct page * dir_get_page(struct inode *dir, unsigned long n)
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 kmap(page);
73 return page;
74}
75
76static inline void *minix_next_entry(void *de, struct minix_sb_info *sbi)
77{
78 return (void*)((char*)de + sbi->s_dirsize);
79}
80
81static int minix_readdir(struct file *file, struct dir_context *ctx)
82{
83 struct inode *inode = file_inode(file);
84 struct super_block *sb = inode->i_sb;
85 struct minix_sb_info *sbi = minix_sb(sb);
86 unsigned chunk_size = sbi->s_dirsize;
87 unsigned long npages = dir_pages(inode);
88 unsigned long pos = ctx->pos;
89 unsigned offset;
90 unsigned long n;
91
92 ctx->pos = pos = ALIGN(pos, chunk_size);
93 if (pos >= inode->i_size)
94 return 0;
95
96 offset = pos & ~PAGE_MASK;
97 n = pos >> PAGE_SHIFT;
98
99 for ( ; n < npages; n++, offset = 0) {
100 char *p, *kaddr, *limit;
101 struct page *page = dir_get_page(inode, n);
102
103 if (IS_ERR(page))
104 continue;
105 kaddr = (char *)page_address(page);
106 p = kaddr+offset;
107 limit = kaddr + minix_last_byte(inode, n) - chunk_size;
108 for ( ; p <= limit; p = minix_next_entry(p, sbi)) {
109 const char *name;
110 __u32 inumber;
111 if (sbi->s_version == MINIX_V3) {
112 minix3_dirent *de3 = (minix3_dirent *)p;
113 name = de3->name;
114 inumber = de3->inode;
115 } else {
116 minix_dirent *de = (minix_dirent *)p;
117 name = de->name;
118 inumber = de->inode;
119 }
120 if (inumber) {
121 unsigned l = strnlen(name, sbi->s_namelen);
122 if (!dir_emit(ctx, name, l,
123 inumber, DT_UNKNOWN)) {
124 dir_put_page(page);
125 return 0;
126 }
127 }
128 ctx->pos += chunk_size;
129 }
130 dir_put_page(page);
131 }
132 return 0;
133}
134
135static inline int namecompare(int len, int maxlen,
136 const char * name, const char * buffer)
137{
138 if (len < maxlen && buffer[len])
139 return 0;
140 return !memcmp(name, buffer, len);
141}
142
143/*
144 * minix_find_entry()
145 *
146 * finds an entry in the specified directory with the wanted name. It
147 * returns the cache buffer in which the entry was found, and the entry
148 * itself (as a parameter - res_dir). It does NOT read the inode of the
149 * entry - you'll have to do that yourself if you want to.
150 */
151minix_dirent *minix_find_entry(struct dentry *dentry, struct page **res_page)
152{
153 const char * name = dentry->d_name.name;
154 int namelen = dentry->d_name.len;
155 struct inode * dir = d_inode(dentry->d_parent);
156 struct super_block * sb = dir->i_sb;
157 struct minix_sb_info * sbi = minix_sb(sb);
158 unsigned long n;
159 unsigned long npages = dir_pages(dir);
160 struct page *page = NULL;
161 char *p;
162
163 char *namx;
164 __u32 inumber;
165 *res_page = NULL;
166
167 for (n = 0; n < npages; n++) {
168 char *kaddr, *limit;
169
170 page = dir_get_page(dir, n);
171 if (IS_ERR(page))
172 continue;
173
174 kaddr = (char*)page_address(page);
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 dir_put_page(page);
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 page = dir_get_page(dir, n);
227 err = PTR_ERR(page);
228 if (IS_ERR(page))
229 goto out;
230 lock_page(page);
231 kaddr = (char*)page_address(page);
232 dir_end = kaddr + minix_last_byte(dir, n);
233 limit = kaddr + PAGE_SIZE - sbi->s_dirsize;
234 for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
235 de = (minix_dirent *)p;
236 de3 = (minix3_dirent *)p;
237 if (sbi->s_version == MINIX_V3) {
238 namx = de3->name;
239 inumber = de3->inode;
240 } else {
241 namx = de->name;
242 inumber = de->inode;
243 }
244 if (p == dir_end) {
245 /* We hit i_size */
246 if (sbi->s_version == MINIX_V3)
247 de3->inode = 0;
248 else
249 de->inode = 0;
250 goto got_it;
251 }
252 if (!inumber)
253 goto got_it;
254 err = -EEXIST;
255 if (namecompare(namelen, sbi->s_namelen, name, namx))
256 goto out_unlock;
257 }
258 unlock_page(page);
259 dir_put_page(page);
260 }
261 BUG();
262 return -EINVAL;
263
264got_it:
265 pos = page_offset(page) + p - (char *)page_address(page);
266 err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
267 if (err)
268 goto out_unlock;
269 memcpy (namx, name, namelen);
270 if (sbi->s_version == MINIX_V3) {
271 memset (namx + namelen, 0, sbi->s_dirsize - namelen - 4);
272 de3->inode = inode->i_ino;
273 } else {
274 memset (namx + namelen, 0, sbi->s_dirsize - namelen - 2);
275 de->inode = inode->i_ino;
276 }
277 err = dir_commit_chunk(page, pos, sbi->s_dirsize);
278 dir->i_mtime = dir->i_ctime = current_time(dir);
279 mark_inode_dirty(dir);
280out_put:
281 dir_put_page(page);
282out:
283 return err;
284out_unlock:
285 unlock_page(page);
286 goto out_put;
287}
288
289int minix_delete_entry(struct minix_dir_entry *de, struct page *page)
290{
291 struct inode *inode = page->mapping->host;
292 char *kaddr = page_address(page);
293 loff_t pos = page_offset(page) + (char*)de - kaddr;
294 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
295 unsigned len = sbi->s_dirsize;
296 int err;
297
298 lock_page(page);
299 err = minix_prepare_chunk(page, pos, len);
300 if (err == 0) {
301 if (sbi->s_version == MINIX_V3)
302 ((minix3_dirent *) de)->inode = 0;
303 else
304 de->inode = 0;
305 err = dir_commit_chunk(page, pos, len);
306 } else {
307 unlock_page(page);
308 }
309 dir_put_page(page);
310 inode->i_ctime = inode->i_mtime = current_time(inode);
311 mark_inode_dirty(inode);
312 return err;
313}
314
315int minix_make_empty(struct inode *inode, struct inode *dir)
316{
317 struct page *page = grab_cache_page(inode->i_mapping, 0);
318 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
319 char *kaddr;
320 int err;
321
322 if (!page)
323 return -ENOMEM;
324 err = minix_prepare_chunk(page, 0, 2 * sbi->s_dirsize);
325 if (err) {
326 unlock_page(page);
327 goto fail;
328 }
329
330 kaddr = kmap_atomic(page);
331 memset(kaddr, 0, PAGE_SIZE);
332
333 if (sbi->s_version == MINIX_V3) {
334 minix3_dirent *de3 = (minix3_dirent *)kaddr;
335
336 de3->inode = inode->i_ino;
337 strcpy(de3->name, ".");
338 de3 = minix_next_entry(de3, sbi);
339 de3->inode = dir->i_ino;
340 strcpy(de3->name, "..");
341 } else {
342 minix_dirent *de = (minix_dirent *)kaddr;
343
344 de->inode = inode->i_ino;
345 strcpy(de->name, ".");
346 de = minix_next_entry(de, sbi);
347 de->inode = dir->i_ino;
348 strcpy(de->name, "..");
349 }
350 kunmap_atomic(kaddr);
351
352 err = dir_commit_chunk(page, 0, 2 * sbi->s_dirsize);
353fail:
354 put_page(page);
355 return err;
356}
357
358/*
359 * routine to check that the specified directory is empty (for rmdir)
360 */
361int minix_empty_dir(struct inode * inode)
362{
363 struct page *page = NULL;
364 unsigned long i, npages = dir_pages(inode);
365 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
366 char *name;
367 __u32 inumber;
368
369 for (i = 0; i < npages; i++) {
370 char *p, *kaddr, *limit;
371
372 page = dir_get_page(inode, i);
373 if (IS_ERR(page))
374 continue;
375
376 kaddr = (char *)page_address(page);
377 limit = kaddr + minix_last_byte(inode, i) - sbi->s_dirsize;
378 for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
379 if (sbi->s_version == MINIX_V3) {
380 minix3_dirent *de3 = (minix3_dirent *)p;
381 name = de3->name;
382 inumber = de3->inode;
383 } else {
384 minix_dirent *de = (minix_dirent *)p;
385 name = de->name;
386 inumber = de->inode;
387 }
388
389 if (inumber != 0) {
390 /* check for . and .. */
391 if (name[0] != '.')
392 goto not_empty;
393 if (!name[1]) {
394 if (inumber != inode->i_ino)
395 goto not_empty;
396 } else if (name[1] != '.')
397 goto not_empty;
398 else if (name[2])
399 goto not_empty;
400 }
401 }
402 dir_put_page(page);
403 }
404 return 1;
405
406not_empty:
407 dir_put_page(page);
408 return 0;
409}
410
411/* Releases the page */
412void minix_set_link(struct minix_dir_entry *de, struct page *page,
413 struct inode *inode)
414{
415 struct inode *dir = page->mapping->host;
416 struct minix_sb_info *sbi = minix_sb(dir->i_sb);
417 loff_t pos = page_offset(page) +
418 (char *)de-(char*)page_address(page);
419 int err;
420
421 lock_page(page);
422
423 err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
424 if (err == 0) {
425 if (sbi->s_version == MINIX_V3)
426 ((minix3_dirent *) de)->inode = inode->i_ino;
427 else
428 de->inode = inode->i_ino;
429 err = dir_commit_chunk(page, pos, sbi->s_dirsize);
430 } else {
431 unlock_page(page);
432 }
433 dir_put_page(page);
434 dir->i_mtime = dir->i_ctime = current_time(dir);
435 mark_inode_dirty(dir);
436}
437
438struct minix_dir_entry * minix_dotdot (struct inode *dir, struct page **p)
439{
440 struct page *page = dir_get_page(dir, 0);
441 struct minix_sb_info *sbi = minix_sb(dir->i_sb);
442 struct minix_dir_entry *de = NULL;
443
444 if (!IS_ERR(page)) {
445 de = minix_next_entry(page_address(page), sbi);
446 *p = page;
447 }
448 return de;
449}
450
451ino_t minix_inode_by_name(struct dentry *dentry)
452{
453 struct page *page;
454 struct minix_dir_entry *de = minix_find_entry(dentry, &page);
455 ino_t res = 0;
456
457 if (de) {
458 struct address_space *mapping = page->mapping;
459 struct inode *inode = mapping->host;
460 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
461
462 if (sbi->s_version == MINIX_V3)
463 res = ((minix3_dirent *) de)->inode;
464 else
465 res = de->inode;
466 dir_put_page(page);
467 }
468 return res;
469}
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 page_cache_release(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_CACHE_SIZE;
42
43 if (page_nr == (inode->i_size >> PAGE_CACHE_SHIFT))
44 last_byte = inode->i_size & (PAGE_CACHE_SIZE - 1);
45 return last_byte;
46}
47
48static inline unsigned long dir_pages(struct inode *inode)
49{
50 return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT;
51}
52
53static int dir_commit_chunk(struct page *page, loff_t pos, unsigned len)
54{
55 struct address_space *mapping = page->mapping;
56 struct inode *dir = mapping->host;
57 int err = 0;
58 block_write_end(NULL, mapping, pos, len, len, page, NULL);
59
60 if (pos+len > dir->i_size) {
61 i_size_write(dir, pos+len);
62 mark_inode_dirty(dir);
63 }
64 if (IS_DIRSYNC(dir))
65 err = write_one_page(page, 1);
66 else
67 unlock_page(page);
68 return err;
69}
70
71static struct page * dir_get_page(struct inode *dir, unsigned long n)
72{
73 struct address_space *mapping = dir->i_mapping;
74 struct page *page = read_mapping_page(mapping, n, NULL);
75 if (!IS_ERR(page))
76 kmap(page);
77 return page;
78}
79
80static inline void *minix_next_entry(void *de, struct minix_sb_info *sbi)
81{
82 return (void*)((char*)de + sbi->s_dirsize);
83}
84
85static int minix_readdir(struct file *file, struct dir_context *ctx)
86{
87 struct inode *inode = file_inode(file);
88 struct super_block *sb = inode->i_sb;
89 struct minix_sb_info *sbi = minix_sb(sb);
90 unsigned chunk_size = sbi->s_dirsize;
91 unsigned long npages = dir_pages(inode);
92 unsigned long pos = ctx->pos;
93 unsigned offset;
94 unsigned long n;
95
96 ctx->pos = pos = ALIGN(pos, chunk_size);
97 if (pos >= inode->i_size)
98 return 0;
99
100 offset = pos & ~PAGE_CACHE_MASK;
101 n = pos >> PAGE_CACHE_SHIFT;
102
103 for ( ; n < npages; n++, offset = 0) {
104 char *p, *kaddr, *limit;
105 struct page *page = dir_get_page(inode, n);
106
107 if (IS_ERR(page))
108 continue;
109 kaddr = (char *)page_address(page);
110 p = kaddr+offset;
111 limit = kaddr + minix_last_byte(inode, n) - chunk_size;
112 for ( ; p <= limit; p = minix_next_entry(p, sbi)) {
113 const char *name;
114 __u32 inumber;
115 if (sbi->s_version == MINIX_V3) {
116 minix3_dirent *de3 = (minix3_dirent *)p;
117 name = de3->name;
118 inumber = de3->inode;
119 } else {
120 minix_dirent *de = (minix_dirent *)p;
121 name = de->name;
122 inumber = de->inode;
123 }
124 if (inumber) {
125 unsigned l = strnlen(name, sbi->s_namelen);
126 if (!dir_emit(ctx, name, l,
127 inumber, DT_UNKNOWN)) {
128 dir_put_page(page);
129 return 0;
130 }
131 }
132 ctx->pos += chunk_size;
133 }
134 dir_put_page(page);
135 }
136 return 0;
137}
138
139static inline int namecompare(int len, int maxlen,
140 const char * name, const char * buffer)
141{
142 if (len < maxlen && buffer[len])
143 return 0;
144 return !memcmp(name, buffer, len);
145}
146
147/*
148 * minix_find_entry()
149 *
150 * finds an entry in the specified directory with the wanted name. It
151 * returns the cache buffer in which the entry was found, and the entry
152 * itself (as a parameter - res_dir). It does NOT read the inode of the
153 * entry - you'll have to do that yourself if you want to.
154 */
155minix_dirent *minix_find_entry(struct dentry *dentry, struct page **res_page)
156{
157 const char * name = dentry->d_name.name;
158 int namelen = dentry->d_name.len;
159 struct inode * dir = dentry->d_parent->d_inode;
160 struct super_block * sb = dir->i_sb;
161 struct minix_sb_info * sbi = minix_sb(sb);
162 unsigned long n;
163 unsigned long npages = dir_pages(dir);
164 struct page *page = NULL;
165 char *p;
166
167 char *namx;
168 __u32 inumber;
169 *res_page = NULL;
170
171 for (n = 0; n < npages; n++) {
172 char *kaddr, *limit;
173
174 page = dir_get_page(dir, n);
175 if (IS_ERR(page))
176 continue;
177
178 kaddr = (char*)page_address(page);
179 limit = kaddr + minix_last_byte(dir, n) - sbi->s_dirsize;
180 for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
181 if (sbi->s_version == MINIX_V3) {
182 minix3_dirent *de3 = (minix3_dirent *)p;
183 namx = de3->name;
184 inumber = de3->inode;
185 } else {
186 minix_dirent *de = (minix_dirent *)p;
187 namx = de->name;
188 inumber = de->inode;
189 }
190 if (!inumber)
191 continue;
192 if (namecompare(namelen, sbi->s_namelen, name, namx))
193 goto found;
194 }
195 dir_put_page(page);
196 }
197 return NULL;
198
199found:
200 *res_page = page;
201 return (minix_dirent *)p;
202}
203
204int minix_add_link(struct dentry *dentry, struct inode *inode)
205{
206 struct inode *dir = dentry->d_parent->d_inode;
207 const char * name = dentry->d_name.name;
208 int namelen = dentry->d_name.len;
209 struct super_block * sb = dir->i_sb;
210 struct minix_sb_info * sbi = minix_sb(sb);
211 struct page *page = NULL;
212 unsigned long npages = dir_pages(dir);
213 unsigned long n;
214 char *kaddr, *p;
215 minix_dirent *de;
216 minix3_dirent *de3;
217 loff_t pos;
218 int err;
219 char *namx = NULL;
220 __u32 inumber;
221
222 /*
223 * We take care of directory expansion in the same loop
224 * This code plays outside i_size, so it locks the page
225 * to protect that region.
226 */
227 for (n = 0; n <= npages; n++) {
228 char *limit, *dir_end;
229
230 page = dir_get_page(dir, n);
231 err = PTR_ERR(page);
232 if (IS_ERR(page))
233 goto out;
234 lock_page(page);
235 kaddr = (char*)page_address(page);
236 dir_end = kaddr + minix_last_byte(dir, n);
237 limit = kaddr + PAGE_CACHE_SIZE - sbi->s_dirsize;
238 for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
239 de = (minix_dirent *)p;
240 de3 = (minix3_dirent *)p;
241 if (sbi->s_version == MINIX_V3) {
242 namx = de3->name;
243 inumber = de3->inode;
244 } else {
245 namx = de->name;
246 inumber = de->inode;
247 }
248 if (p == dir_end) {
249 /* We hit i_size */
250 if (sbi->s_version == MINIX_V3)
251 de3->inode = 0;
252 else
253 de->inode = 0;
254 goto got_it;
255 }
256 if (!inumber)
257 goto got_it;
258 err = -EEXIST;
259 if (namecompare(namelen, sbi->s_namelen, name, namx))
260 goto out_unlock;
261 }
262 unlock_page(page);
263 dir_put_page(page);
264 }
265 BUG();
266 return -EINVAL;
267
268got_it:
269 pos = page_offset(page) + p - (char *)page_address(page);
270 err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
271 if (err)
272 goto out_unlock;
273 memcpy (namx, name, namelen);
274 if (sbi->s_version == MINIX_V3) {
275 memset (namx + namelen, 0, sbi->s_dirsize - namelen - 4);
276 de3->inode = inode->i_ino;
277 } else {
278 memset (namx + namelen, 0, sbi->s_dirsize - namelen - 2);
279 de->inode = inode->i_ino;
280 }
281 err = dir_commit_chunk(page, pos, sbi->s_dirsize);
282 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
283 mark_inode_dirty(dir);
284out_put:
285 dir_put_page(page);
286out:
287 return err;
288out_unlock:
289 unlock_page(page);
290 goto out_put;
291}
292
293int minix_delete_entry(struct minix_dir_entry *de, struct page *page)
294{
295 struct inode *inode = page->mapping->host;
296 char *kaddr = page_address(page);
297 loff_t pos = page_offset(page) + (char*)de - kaddr;
298 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
299 unsigned len = sbi->s_dirsize;
300 int err;
301
302 lock_page(page);
303 err = minix_prepare_chunk(page, pos, len);
304 if (err == 0) {
305 if (sbi->s_version == MINIX_V3)
306 ((minix3_dirent *) de)->inode = 0;
307 else
308 de->inode = 0;
309 err = dir_commit_chunk(page, pos, len);
310 } else {
311 unlock_page(page);
312 }
313 dir_put_page(page);
314 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
315 mark_inode_dirty(inode);
316 return err;
317}
318
319int minix_make_empty(struct inode *inode, struct inode *dir)
320{
321 struct page *page = grab_cache_page(inode->i_mapping, 0);
322 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
323 char *kaddr;
324 int err;
325
326 if (!page)
327 return -ENOMEM;
328 err = minix_prepare_chunk(page, 0, 2 * sbi->s_dirsize);
329 if (err) {
330 unlock_page(page);
331 goto fail;
332 }
333
334 kaddr = kmap_atomic(page);
335 memset(kaddr, 0, PAGE_CACHE_SIZE);
336
337 if (sbi->s_version == MINIX_V3) {
338 minix3_dirent *de3 = (minix3_dirent *)kaddr;
339
340 de3->inode = inode->i_ino;
341 strcpy(de3->name, ".");
342 de3 = minix_next_entry(de3, sbi);
343 de3->inode = dir->i_ino;
344 strcpy(de3->name, "..");
345 } else {
346 minix_dirent *de = (minix_dirent *)kaddr;
347
348 de->inode = inode->i_ino;
349 strcpy(de->name, ".");
350 de = minix_next_entry(de, sbi);
351 de->inode = dir->i_ino;
352 strcpy(de->name, "..");
353 }
354 kunmap_atomic(kaddr);
355
356 err = dir_commit_chunk(page, 0, 2 * sbi->s_dirsize);
357fail:
358 page_cache_release(page);
359 return err;
360}
361
362/*
363 * routine to check that the specified directory is empty (for rmdir)
364 */
365int minix_empty_dir(struct inode * inode)
366{
367 struct page *page = NULL;
368 unsigned long i, npages = dir_pages(inode);
369 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
370 char *name;
371 __u32 inumber;
372
373 for (i = 0; i < npages; i++) {
374 char *p, *kaddr, *limit;
375
376 page = dir_get_page(inode, i);
377 if (IS_ERR(page))
378 continue;
379
380 kaddr = (char *)page_address(page);
381 limit = kaddr + minix_last_byte(inode, i) - sbi->s_dirsize;
382 for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
383 if (sbi->s_version == MINIX_V3) {
384 minix3_dirent *de3 = (minix3_dirent *)p;
385 name = de3->name;
386 inumber = de3->inode;
387 } else {
388 minix_dirent *de = (minix_dirent *)p;
389 name = de->name;
390 inumber = de->inode;
391 }
392
393 if (inumber != 0) {
394 /* check for . and .. */
395 if (name[0] != '.')
396 goto not_empty;
397 if (!name[1]) {
398 if (inumber != inode->i_ino)
399 goto not_empty;
400 } else if (name[1] != '.')
401 goto not_empty;
402 else if (name[2])
403 goto not_empty;
404 }
405 }
406 dir_put_page(page);
407 }
408 return 1;
409
410not_empty:
411 dir_put_page(page);
412 return 0;
413}
414
415/* Releases the page */
416void minix_set_link(struct minix_dir_entry *de, struct page *page,
417 struct inode *inode)
418{
419 struct inode *dir = page->mapping->host;
420 struct minix_sb_info *sbi = minix_sb(dir->i_sb);
421 loff_t pos = page_offset(page) +
422 (char *)de-(char*)page_address(page);
423 int err;
424
425 lock_page(page);
426
427 err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
428 if (err == 0) {
429 if (sbi->s_version == MINIX_V3)
430 ((minix3_dirent *) de)->inode = inode->i_ino;
431 else
432 de->inode = inode->i_ino;
433 err = dir_commit_chunk(page, pos, sbi->s_dirsize);
434 } else {
435 unlock_page(page);
436 }
437 dir_put_page(page);
438 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
439 mark_inode_dirty(dir);
440}
441
442struct minix_dir_entry * minix_dotdot (struct inode *dir, struct page **p)
443{
444 struct page *page = dir_get_page(dir, 0);
445 struct minix_sb_info *sbi = minix_sb(dir->i_sb);
446 struct minix_dir_entry *de = NULL;
447
448 if (!IS_ERR(page)) {
449 de = minix_next_entry(page_address(page), sbi);
450 *p = page;
451 }
452 return de;
453}
454
455ino_t minix_inode_by_name(struct dentry *dentry)
456{
457 struct page *page;
458 struct minix_dir_entry *de = minix_find_entry(dentry, &page);
459 ino_t res = 0;
460
461 if (de) {
462 struct address_space *mapping = page->mapping;
463 struct inode *inode = mapping->host;
464 struct minix_sb_info *sbi = minix_sb(inode->i_sb);
465
466 if (sbi->s_version == MINIX_V3)
467 res = ((minix3_dirent *) de)->inode;
468 else
469 res = de->inode;
470 dir_put_page(page);
471 }
472 return res;
473}