~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/ufs/dir.c

Version: ~ [ linux-5.5-rc1 ] ~ [ linux-5.4.2 ] ~ [ linux-5.3.15 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.88 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.158 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.206 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.206 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  *  linux/fs/ufs/ufs_dir.c
  3  *
  4  * Copyright (C) 1996
  5  * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
  6  * Laboratory for Computer Science Research Computing Facility
  7  * Rutgers, The State University of New Jersey
  8  *
  9  * swab support by Francois-Rene Rideau <fare@tunes.org> 19970406
 10  *
 11  * 4.4BSD (FreeBSD) support added on February 1st 1998 by
 12  * Niels Kristian Bech Jensen <nkbj@image.dk> partially based
 13  * on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>.
 14  *
 15  * Migration to usage of "page cache" on May 2006 by
 16  * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
 17  */
 18 
 19 #include <linux/time.h>
 20 #include <linux/fs.h>
 21 #include <linux/swap.h>
 22 
 23 #include "ufs_fs.h"
 24 #include "ufs.h"
 25 #include "swab.h"
 26 #include "util.h"
 27 
 28 /*
 29  * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
 30  *
 31  * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
 32  */
 33 static inline int ufs_match(struct super_block *sb, int len,
 34                 const unsigned char *name, struct ufs_dir_entry *de)
 35 {
 36         if (len != ufs_get_de_namlen(sb, de))
 37                 return 0;
 38         if (!de->d_ino)
 39                 return 0;
 40         return !memcmp(name, de->d_name, len);
 41 }
 42 
 43 static int ufs_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         int err = 0;
 48 
 49         dir->i_version++;
 50         block_write_end(NULL, mapping, pos, len, len, page, NULL);
 51         if (pos+len > dir->i_size) {
 52                 i_size_write(dir, pos+len);
 53                 mark_inode_dirty(dir);
 54         }
 55         if (IS_DIRSYNC(dir))
 56                 err = write_one_page(page, 1);
 57         else
 58                 unlock_page(page);
 59         return err;
 60 }
 61 
 62 static inline void ufs_put_page(struct page *page)
 63 {
 64         kunmap(page);
 65         page_cache_release(page);
 66 }
 67 
 68 static inline unsigned long ufs_dir_pages(struct inode *inode)
 69 {
 70         return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT;
 71 }
 72 
 73 ino_t ufs_inode_by_name(struct inode *dir, const struct qstr *qstr)
 74 {
 75         ino_t res = 0;
 76         struct ufs_dir_entry *de;
 77         struct page *page;
 78         
 79         de = ufs_find_entry(dir, qstr, &page);
 80         if (de) {
 81                 res = fs32_to_cpu(dir->i_sb, de->d_ino);
 82                 ufs_put_page(page);
 83         }
 84         return res;
 85 }
 86 
 87 
 88 /* Releases the page */
 89 void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
 90                   struct page *page, struct inode *inode)
 91 {
 92         loff_t pos = page_offset(page) +
 93                         (char *) de - (char *) page_address(page);
 94         unsigned len = fs16_to_cpu(dir->i_sb, de->d_reclen);
 95         int err;
 96 
 97         lock_page(page);
 98         err = ufs_prepare_chunk(page, pos, len);
 99         BUG_ON(err);
100 
101         de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
102         ufs_set_de_type(dir->i_sb, de, inode->i_mode);
103 
104         err = ufs_commit_chunk(page, pos, len);
105         ufs_put_page(page);
106         dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
107         mark_inode_dirty(dir);
108 }
109 
110 
111 static void ufs_check_page(struct page *page)
112 {
113         struct inode *dir = page->mapping->host;
114         struct super_block *sb = dir->i_sb;
115         char *kaddr = page_address(page);
116         unsigned offs, rec_len;
117         unsigned limit = PAGE_CACHE_SIZE;
118         const unsigned chunk_mask = UFS_SB(sb)->s_uspi->s_dirblksize - 1;
119         struct ufs_dir_entry *p;
120         char *error;
121 
122         if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) {
123                 limit = dir->i_size & ~PAGE_CACHE_MASK;
124                 if (limit & chunk_mask)
125                         goto Ebadsize;
126                 if (!limit)
127                         goto out;
128         }
129         for (offs = 0; offs <= limit - UFS_DIR_REC_LEN(1); offs += rec_len) {
130                 p = (struct ufs_dir_entry *)(kaddr + offs);
131                 rec_len = fs16_to_cpu(sb, p->d_reclen);
132 
133                 if (rec_len < UFS_DIR_REC_LEN(1))
134                         goto Eshort;
135                 if (rec_len & 3)
136                         goto Ealign;
137                 if (rec_len < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, p)))
138                         goto Enamelen;
139                 if (((offs + rec_len - 1) ^ offs) & ~chunk_mask)
140                         goto Espan;
141                 if (fs32_to_cpu(sb, p->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg *
142                                                   UFS_SB(sb)->s_uspi->s_ncg))
143                         goto Einumber;
144         }
145         if (offs != limit)
146                 goto Eend;
147 out:
148         SetPageChecked(page);
149         return;
150 
151         /* Too bad, we had an error */
152 
153 Ebadsize:
154         ufs_error(sb, "ufs_check_page",
155                   "size of directory #%lu is not a multiple of chunk size",
156                   dir->i_ino
157         );
158         goto fail;
159 Eshort:
160         error = "rec_len is smaller than minimal";
161         goto bad_entry;
162 Ealign:
163         error = "unaligned directory entry";
164         goto bad_entry;
165 Enamelen:
166         error = "rec_len is too small for name_len";
167         goto bad_entry;
168 Espan:
169         error = "directory entry across blocks";
170         goto bad_entry;
171 Einumber:
172         error = "inode out of bounds";
173 bad_entry:
174         ufs_error (sb, "ufs_check_page", "bad entry in directory #%lu: %s - "
175                    "offset=%lu, rec_len=%d, name_len=%d",
176                    dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
177                    rec_len, ufs_get_de_namlen(sb, p));
178         goto fail;
179 Eend:
180         p = (struct ufs_dir_entry *)(kaddr + offs);
181         ufs_error(sb, __func__,
182                    "entry in directory #%lu spans the page boundary"
183                    "offset=%lu",
184                    dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs);
185 fail:
186         SetPageChecked(page);
187         SetPageError(page);
188 }
189 
190 static struct page *ufs_get_page(struct inode *dir, unsigned long n)
191 {
192         struct address_space *mapping = dir->i_mapping;
193         struct page *page = read_mapping_page(mapping, n, NULL);
194         if (!IS_ERR(page)) {
195                 kmap(page);
196                 if (!PageChecked(page))
197                         ufs_check_page(page);
198                 if (PageError(page))
199                         goto fail;
200         }
201         return page;
202 
203 fail:
204         ufs_put_page(page);
205         return ERR_PTR(-EIO);
206 }
207 
208 /*
209  * Return the offset into page `page_nr' of the last valid
210  * byte in that page, plus one.
211  */
212 static unsigned
213 ufs_last_byte(struct inode *inode, unsigned long page_nr)
214 {
215         unsigned last_byte = inode->i_size;
216 
217         last_byte -= page_nr << PAGE_CACHE_SHIFT;
218         if (last_byte > PAGE_CACHE_SIZE)
219                 last_byte = PAGE_CACHE_SIZE;
220         return last_byte;
221 }
222 
223 static inline struct ufs_dir_entry *
224 ufs_next_entry(struct super_block *sb, struct ufs_dir_entry *p)
225 {
226         return (struct ufs_dir_entry *)((char *)p +
227                                         fs16_to_cpu(sb, p->d_reclen));
228 }
229 
230 struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct page **p)
231 {
232         struct page *page = ufs_get_page(dir, 0);
233         struct ufs_dir_entry *de = NULL;
234 
235         if (!IS_ERR(page)) {
236                 de = ufs_next_entry(dir->i_sb,
237                                     (struct ufs_dir_entry *)page_address(page));
238                 *p = page;
239         }
240         return de;
241 }
242 
243 /*
244  *      ufs_find_entry()
245  *
246  * finds an entry in the specified directory with the wanted name. It
247  * returns the page in which the entry was found, and the entry itself
248  * (as a parameter - res_dir). Page is returned mapped and unlocked.
249  * Entry is guaranteed to be valid.
250  */
251 struct ufs_dir_entry *ufs_find_entry(struct inode *dir, const struct qstr *qstr,
252                                      struct page **res_page)
253 {
254         struct super_block *sb = dir->i_sb;
255         const unsigned char *name = qstr->name;
256         int namelen = qstr->len;
257         unsigned reclen = UFS_DIR_REC_LEN(namelen);
258         unsigned long start, n;
259         unsigned long npages = ufs_dir_pages(dir);
260         struct page *page = NULL;
261         struct ufs_inode_info *ui = UFS_I(dir);
262         struct ufs_dir_entry *de;
263 
264         UFSD("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen);
265 
266         if (npages == 0 || namelen > UFS_MAXNAMLEN)
267                 goto out;
268 
269         /* OFFSET_CACHE */
270         *res_page = NULL;
271 
272         start = ui->i_dir_start_lookup;
273 
274         if (start >= npages)
275                 start = 0;
276         n = start;
277         do {
278                 char *kaddr;
279                 page = ufs_get_page(dir, n);
280                 if (!IS_ERR(page)) {
281                         kaddr = page_address(page);
282                         de = (struct ufs_dir_entry *) kaddr;
283                         kaddr += ufs_last_byte(dir, n) - reclen;
284                         while ((char *) de <= kaddr) {
285                                 if (de->d_reclen == 0) {
286                                         ufs_error(dir->i_sb, __func__,
287                                                   "zero-length directory entry");
288                                         ufs_put_page(page);
289                                         goto out;
290                                 }
291                                 if (ufs_match(sb, namelen, name, de))
292                                         goto found;
293                                 de = ufs_next_entry(sb, de);
294                         }
295                         ufs_put_page(page);
296                 }
297                 if (++n >= npages)
298                         n = 0;
299         } while (n != start);
300 out:
301         return NULL;
302 
303 found:
304         *res_page = page;
305         ui->i_dir_start_lookup = n;
306         return de;
307 }
308 
309 /*
310  *      Parent is locked.
311  */
312 int ufs_add_link(struct dentry *dentry, struct inode *inode)
313 {
314         struct inode *dir = dentry->d_parent->d_inode;
315         const unsigned char *name = dentry->d_name.name;
316         int namelen = dentry->d_name.len;
317         struct super_block *sb = dir->i_sb;
318         unsigned reclen = UFS_DIR_REC_LEN(namelen);
319         const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
320         unsigned short rec_len, name_len;
321         struct page *page = NULL;
322         struct ufs_dir_entry *de;
323         unsigned long npages = ufs_dir_pages(dir);
324         unsigned long n;
325         char *kaddr;
326         loff_t pos;
327         int err;
328 
329         UFSD("ENTER, name %s, namelen %u\n", name, namelen);
330 
331         /*
332          * We take care of directory expansion in the same loop.
333          * This code plays outside i_size, so it locks the page
334          * to protect that region.
335          */
336         for (n = 0; n <= npages; n++) {
337                 char *dir_end;
338 
339                 page = ufs_get_page(dir, n);
340                 err = PTR_ERR(page);
341                 if (IS_ERR(page))
342                         goto out;
343                 lock_page(page);
344                 kaddr = page_address(page);
345                 dir_end = kaddr + ufs_last_byte(dir, n);
346                 de = (struct ufs_dir_entry *)kaddr;
347                 kaddr += PAGE_CACHE_SIZE - reclen;
348                 while ((char *)de <= kaddr) {
349                         if ((char *)de == dir_end) {
350                                 /* We hit i_size */
351                                 name_len = 0;
352                                 rec_len = chunk_size;
353                                 de->d_reclen = cpu_to_fs16(sb, chunk_size);
354                                 de->d_ino = 0;
355                                 goto got_it;
356                         }
357                         if (de->d_reclen == 0) {
358                                 ufs_error(dir->i_sb, __func__,
359                                           "zero-length directory entry");
360                                 err = -EIO;
361                                 goto out_unlock;
362                         }
363                         err = -EEXIST;
364                         if (ufs_match(sb, namelen, name, de))
365                                 goto out_unlock;
366                         name_len = UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de));
367                         rec_len = fs16_to_cpu(sb, de->d_reclen);
368                         if (!de->d_ino && rec_len >= reclen)
369                                 goto got_it;
370                         if (rec_len >= name_len + reclen)
371                                 goto got_it;
372                         de = (struct ufs_dir_entry *) ((char *) de + rec_len);
373                 }
374                 unlock_page(page);
375                 ufs_put_page(page);
376         }
377         BUG();
378         return -EINVAL;
379 
380 got_it:
381         pos = page_offset(page) +
382                         (char*)de - (char*)page_address(page);
383         err = ufs_prepare_chunk(page, pos, rec_len);
384         if (err)
385                 goto out_unlock;
386         if (de->d_ino) {
387                 struct ufs_dir_entry *de1 =
388                         (struct ufs_dir_entry *) ((char *) de + name_len);
389                 de1->d_reclen = cpu_to_fs16(sb, rec_len - name_len);
390                 de->d_reclen = cpu_to_fs16(sb, name_len);
391 
392                 de = de1;
393         }
394 
395         ufs_set_de_namlen(sb, de, namelen);
396         memcpy(de->d_name, name, namelen + 1);
397         de->d_ino = cpu_to_fs32(sb, inode->i_ino);
398         ufs_set_de_type(sb, de, inode->i_mode);
399 
400         err = ufs_commit_chunk(page, pos, rec_len);
401         dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
402 
403         mark_inode_dirty(dir);
404         /* OFFSET_CACHE */
405 out_put:
406         ufs_put_page(page);
407 out:
408         return err;
409 out_unlock:
410         unlock_page(page);
411         goto out_put;
412 }
413 
414 static inline unsigned
415 ufs_validate_entry(struct super_block *sb, char *base,
416                    unsigned offset, unsigned mask)
417 {
418         struct ufs_dir_entry *de = (struct ufs_dir_entry*)(base + offset);
419         struct ufs_dir_entry *p = (struct ufs_dir_entry*)(base + (offset&mask));
420         while ((char*)p < (char*)de) {
421                 if (p->d_reclen == 0)
422                         break;
423                 p = ufs_next_entry(sb, p);
424         }
425         return (char *)p - base;
426 }
427 
428 
429 /*
430  * This is blatantly stolen from ext2fs
431  */
432 static int
433 ufs_readdir(struct file *filp, void *dirent, filldir_t filldir)
434 {
435         loff_t pos = filp->f_pos;
436         struct inode *inode = filp->f_path.dentry->d_inode;
437         struct super_block *sb = inode->i_sb;
438         unsigned int offset = pos & ~PAGE_CACHE_MASK;
439         unsigned long n = pos >> PAGE_CACHE_SHIFT;
440         unsigned long npages = ufs_dir_pages(inode);
441         unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
442         int need_revalidate = filp->f_version != inode->i_version;
443         unsigned flags = UFS_SB(sb)->s_flags;
444 
445         UFSD("BEGIN\n");
446 
447         if (pos > inode->i_size - UFS_DIR_REC_LEN(1))
448                 return 0;
449 
450         for ( ; n < npages; n++, offset = 0) {
451                 char *kaddr, *limit;
452                 struct ufs_dir_entry *de;
453 
454                 struct page *page = ufs_get_page(inode, n);
455 
456                 if (IS_ERR(page)) {
457                         ufs_error(sb, __func__,
458                                   "bad page in #%lu",
459                                   inode->i_ino);
460                         filp->f_pos += PAGE_CACHE_SIZE - offset;
461                         return -EIO;
462                 }
463                 kaddr = page_address(page);
464                 if (unlikely(need_revalidate)) {
465                         if (offset) {
466                                 offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
467                                 filp->f_pos = (n<<PAGE_CACHE_SHIFT) + offset;
468                         }
469                         filp->f_version = inode->i_version;
470                         need_revalidate = 0;
471                 }
472                 de = (struct ufs_dir_entry *)(kaddr+offset);
473                 limit = kaddr + ufs_last_byte(inode, n) - UFS_DIR_REC_LEN(1);
474                 for ( ;(char*)de <= limit; de = ufs_next_entry(sb, de)) {
475                         if (de->d_reclen == 0) {
476                                 ufs_error(sb, __func__,
477                                         "zero-length directory entry");
478                                 ufs_put_page(page);
479                                 return -EIO;
480                         }
481                         if (de->d_ino) {
482                                 int over;
483                                 unsigned char d_type = DT_UNKNOWN;
484 
485                                 offset = (char *)de - kaddr;
486 
487                                 UFSD("filldir(%s,%u)\n", de->d_name,
488                                       fs32_to_cpu(sb, de->d_ino));
489                                 UFSD("namlen %u\n", ufs_get_de_namlen(sb, de));
490 
491                                 if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
492                                         d_type = de->d_u.d_44.d_type;
493 
494                                 over = filldir(dirent, de->d_name,
495                                                ufs_get_de_namlen(sb, de),
496                                                 (n<<PAGE_CACHE_SHIFT) | offset,
497                                                fs32_to_cpu(sb, de->d_ino), d_type);
498                                 if (over) {
499                                         ufs_put_page(page);
500                                         return 0;
501                                 }
502                         }
503                         filp->f_pos += fs16_to_cpu(sb, de->d_reclen);
504                 }
505                 ufs_put_page(page);
506         }
507         return 0;
508 }
509 
510 
511 /*
512  * ufs_delete_entry deletes a directory entry by merging it with the
513  * previous entry.
514  */
515 int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
516                      struct page * page)
517 {
518         struct super_block *sb = inode->i_sb;
519         char *kaddr = page_address(page);
520         unsigned from = ((char*)dir - kaddr) & ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
521         unsigned to = ((char*)dir - kaddr) + fs16_to_cpu(sb, dir->d_reclen);
522         loff_t pos;
523         struct ufs_dir_entry *pde = NULL;
524         struct ufs_dir_entry *de = (struct ufs_dir_entry *) (kaddr + from);
525         int err;
526 
527         UFSD("ENTER\n");
528 
529         UFSD("ino %u, reclen %u, namlen %u, name %s\n",
530               fs32_to_cpu(sb, de->d_ino),
531               fs16_to_cpu(sb, de->d_reclen),
532               ufs_get_de_namlen(sb, de), de->d_name);
533 
534         while ((char*)de < (char*)dir) {
535                 if (de->d_reclen == 0) {
536                         ufs_error(inode->i_sb, __func__,
537                                   "zero-length directory entry");
538                         err = -EIO;
539                         goto out;
540                 }
541                 pde = de;
542                 de = ufs_next_entry(sb, de);
543         }
544         if (pde)
545                 from = (char*)pde - (char*)page_address(page);
546 
547         pos = page_offset(page) + from;
548         lock_page(page);
549         err = ufs_prepare_chunk(page, pos, to - from);
550         BUG_ON(err);
551         if (pde)
552                 pde->d_reclen = cpu_to_fs16(sb, to - from);
553         dir->d_ino = 0;
554         err = ufs_commit_chunk(page, pos, to - from);
555         inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
556         mark_inode_dirty(inode);
557 out:
558         ufs_put_page(page);
559         UFSD("EXIT\n");
560         return err;
561 }
562 
563 int ufs_make_empty(struct inode * inode, struct inode *dir)
564 {
565         struct super_block * sb = dir->i_sb;
566         struct address_space *mapping = inode->i_mapping;
567         struct page *page = grab_cache_page(mapping, 0);
568         const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
569         struct ufs_dir_entry * de;
570         char *base;
571         int err;
572 
573         if (!page)
574                 return -ENOMEM;
575 
576         err = ufs_prepare_chunk(page, 0, chunk_size);
577         if (err) {
578                 unlock_page(page);
579                 goto fail;
580         }
581 
582         kmap(page);
583         base = (char*)page_address(page);
584         memset(base, 0, PAGE_CACHE_SIZE);
585 
586         de = (struct ufs_dir_entry *) base;
587 
588         de->d_ino = cpu_to_fs32(sb, inode->i_ino);
589         ufs_set_de_type(sb, de, inode->i_mode);
590         ufs_set_de_namlen(sb, de, 1);
591         de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
592         strcpy (de->d_name, ".");
593         de = (struct ufs_dir_entry *)
594                 ((char *)de + fs16_to_cpu(sb, de->d_reclen));
595         de->d_ino = cpu_to_fs32(sb, dir->i_ino);
596         ufs_set_de_type(sb, de, dir->i_mode);
597         de->d_reclen = cpu_to_fs16(sb, chunk_size - UFS_DIR_REC_LEN(1));
598         ufs_set_de_namlen(sb, de, 2);
599         strcpy (de->d_name, "..");
600         kunmap(page);
601 
602         err = ufs_commit_chunk(page, 0, chunk_size);
603 fail:
604         page_cache_release(page);
605         return err;
606 }
607 
608 /*
609  * routine to check that the specified directory is empty (for rmdir)
610  */
611 int ufs_empty_dir(struct inode * inode)
612 {
613         struct super_block *sb = inode->i_sb;
614         struct page *page = NULL;
615         unsigned long i, npages = ufs_dir_pages(inode);
616 
617         for (i = 0; i < npages; i++) {
618                 char *kaddr;
619                 struct ufs_dir_entry *de;
620                 page = ufs_get_page(inode, i);
621 
622                 if (IS_ERR(page))
623                         continue;
624 
625                 kaddr = page_address(page);
626                 de = (struct ufs_dir_entry *)kaddr;
627                 kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1);
628 
629                 while ((char *)de <= kaddr) {
630                         if (de->d_reclen == 0) {
631                                 ufs_error(inode->i_sb, __func__,
632                                         "zero-length directory entry: "
633                                         "kaddr=%p, de=%p\n", kaddr, de);
634                                 goto not_empty;
635                         }
636                         if (de->d_ino) {
637                                 u16 namelen=ufs_get_de_namlen(sb, de);
638                                 /* check for . and .. */
639                                 if (de->d_name[0] != '.')
640                                         goto not_empty;
641                                 if (namelen > 2)
642                                         goto not_empty;
643                                 if (namelen < 2) {
644                                         if (inode->i_ino !=
645                                             fs32_to_cpu(sb, de->d_ino))
646                                                 goto not_empty;
647                                 } else if (de->d_name[1] != '.')
648                                         goto not_empty;
649                         }
650                         de = ufs_next_entry(sb, de);
651                 }
652                 ufs_put_page(page);
653         }
654         return 1;
655 
656 not_empty:
657         ufs_put_page(page);
658         return 0;
659 }
660 
661 const struct file_operations ufs_dir_operations = {
662         .read           = generic_read_dir,
663         .readdir        = ufs_readdir,
664         .fsync          = generic_file_fsync,
665         .llseek         = generic_file_llseek,
666 };
667 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp