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netfilter: nft_set_rbtree: fix panic when destroying set by GC
[linux/fpc-iii.git] / fs / coda / dir.c
blob00876ddadb43021396c9c2f010fa2c4fa2e90cd1
1 // SPDX-License-Identifier: GPL-2.0
2
3 /*
4 * Directory operations for Coda filesystem
5 * Original version: (C) 1996 P. Braam and M. Callahan
6 * Rewritten for Linux 2.1. (C) 1997 Carnegie Mellon University
7 *
8 * Carnegie Mellon encourages users to contribute improvements to
9 * the Coda project. Contact Peter Braam (coda@cs.cmu.edu).
10 */
11
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/time.h>
15 #include <linux/fs.h>
16 #include <linux/slab.h>
17 #include <linux/file.h>
18 #include <linux/stat.h>
19 #include <linux/errno.h>
20 #include <linux/string.h>
21 #include <linux/spinlock.h>
22 #include <linux/namei.h>
23 #include <linux/uaccess.h>
24
25 #include <linux/coda.h>
26 #include <linux/coda_psdev.h>
27 #include "coda_linux.h"
28 #include "coda_cache.h"
29
30 #include "coda_int.h"
31
32 /* same as fs/bad_inode.c */
33 static int coda_return_EIO(void)
34 {
35 return -EIO;
36 }
37 #define CODA_EIO_ERROR ((void *) (coda_return_EIO))
38
39 /* inode operations for directories */
40 /* access routines: lookup, readlink, permission */
41 static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, unsigned int flags)
42 {
43 struct super_block *sb = dir->i_sb;
44 const char *name = entry->d_name.name;
45 size_t length = entry->d_name.len;
46 struct inode *inode;
47 int type = 0;
48
49 if (length > CODA_MAXNAMLEN) {
50 pr_err("name too long: lookup, %s (%*s)\n",
51 coda_i2s(dir), (int)length, name);
52 return ERR_PTR(-ENAMETOOLONG);
53 }
54
55 /* control object, create inode on the fly */
56 if (is_root_inode(dir) && coda_iscontrol(name, length)) {
57 inode = coda_cnode_makectl(sb);
58 type = CODA_NOCACHE;
59 } else {
60 struct CodaFid fid = { { 0, } };
61 int error = venus_lookup(sb, coda_i2f(dir), name, length,
62 &type, &fid);
63 inode = !error ? coda_cnode_make(&fid, sb) : ERR_PTR(error);
64 }
65
66 if (!IS_ERR(inode) && (type & CODA_NOCACHE))
67 coda_flag_inode(inode, C_VATTR | C_PURGE);
68
69 if (inode == ERR_PTR(-ENOENT))
70 inode = NULL;
71
72 return d_splice_alias(inode, entry);
73 }
74
75
76 int coda_permission(struct inode *inode, int mask)
77 {
78 int error;
79
80 if (mask & MAY_NOT_BLOCK)
81 return -ECHILD;
82
83 mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
84
85 if (!mask)
86 return 0;
87
88 if ((mask & MAY_EXEC) && !execute_ok(inode))
89 return -EACCES;
90
91 if (coda_cache_check(inode, mask))
92 return 0;
93
94 error = venus_access(inode->i_sb, coda_i2f(inode), mask);
95
96 if (!error)
97 coda_cache_enter(inode, mask);
98
99 return error;
100 }
101
102
103 static inline void coda_dir_update_mtime(struct inode *dir)
104 {
105 #ifdef REQUERY_VENUS_FOR_MTIME
106 /* invalidate the directory cnode's attributes so we refetch the
107 * attributes from venus next time the inode is referenced */
108 coda_flag_inode(dir, C_VATTR);
109 #else
110 /* optimistically we can also act as if our nose bleeds. The
111 * granularity of the mtime is coarse anyways so we might actually be
112 * right most of the time. Note: we only do this for directories. */
113 dir->i_mtime = dir->i_ctime = current_time(dir);
114 #endif
115 }
116
117 /* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
118 * trick to fool GNU find's optimizations. If we can't be sure of the link
119 * (because of volume mount points) we set i_nlink to 1 which forces find
120 * to consider every child as a possible directory. We should also never
121 * see an increment or decrement for deleted directories where i_nlink == 0 */
122 static inline void coda_dir_inc_nlink(struct inode *dir)
123 {
124 if (dir->i_nlink >= 2)
125 inc_nlink(dir);
126 }
127
128 static inline void coda_dir_drop_nlink(struct inode *dir)
129 {
130 if (dir->i_nlink > 2)
131 drop_nlink(dir);
132 }
133
134 /* creation routines: create, mknod, mkdir, link, symlink */
135 static int coda_create(struct inode *dir, struct dentry *de, umode_t mode, bool excl)
136 {
137 int error;
138 const char *name=de->d_name.name;
139 int length=de->d_name.len;
140 struct inode *inode;
141 struct CodaFid newfid;
142 struct coda_vattr attrs;
143
144 if (is_root_inode(dir) && coda_iscontrol(name, length))
145 return -EPERM;
146
147 error = venus_create(dir->i_sb, coda_i2f(dir), name, length,
148 0, mode, &newfid, &attrs);
149 if (error)
150 goto err_out;
151
152 inode = coda_iget(dir->i_sb, &newfid, &attrs);
153 if (IS_ERR(inode)) {
154 error = PTR_ERR(inode);
155 goto err_out;
156 }
157
158 /* invalidate the directory cnode's attributes */
159 coda_dir_update_mtime(dir);
160 d_instantiate(de, inode);
161 return 0;
162 err_out:
163 d_drop(de);
164 return error;
165 }
166
167 static int coda_mkdir(struct inode *dir, struct dentry *de, umode_t mode)
168 {
169 struct inode *inode;
170 struct coda_vattr attrs;
171 const char *name = de->d_name.name;
172 int len = de->d_name.len;
173 int error;
174 struct CodaFid newfid;
175
176 if (is_root_inode(dir) && coda_iscontrol(name, len))
177 return -EPERM;
178
179 attrs.va_mode = mode;
180 error = venus_mkdir(dir->i_sb, coda_i2f(dir),
181 name, len, &newfid, &attrs);
182 if (error)
183 goto err_out;
184
185 inode = coda_iget(dir->i_sb, &newfid, &attrs);
186 if (IS_ERR(inode)) {
187 error = PTR_ERR(inode);
188 goto err_out;
189 }
190
191 /* invalidate the directory cnode's attributes */
192 coda_dir_inc_nlink(dir);
193 coda_dir_update_mtime(dir);
194 d_instantiate(de, inode);
195 return 0;
196 err_out:
197 d_drop(de);
198 return error;
199 }
200
201 /* try to make de an entry in dir_inodde linked to source_de */
202 static int coda_link(struct dentry *source_de, struct inode *dir_inode,
203 struct dentry *de)
204 {
205 struct inode *inode = d_inode(source_de);
206 const char * name = de->d_name.name;
207 int len = de->d_name.len;
208 int error;
209
210 if (is_root_inode(dir_inode) && coda_iscontrol(name, len))
211 return -EPERM;
212
213 error = venus_link(dir_inode->i_sb, coda_i2f(inode),
214 coda_i2f(dir_inode), (const char *)name, len);
215 if (error) {
216 d_drop(de);
217 return error;
218 }
219
220 coda_dir_update_mtime(dir_inode);
221 ihold(inode);
222 d_instantiate(de, inode);
223 inc_nlink(inode);
224 return 0;
225 }
226
227
228 static int coda_symlink(struct inode *dir_inode, struct dentry *de,
229 const char *symname)
230 {
231 const char *name = de->d_name.name;
232 int len = de->d_name.len;
233 int symlen;
234 int error;
235
236 if (is_root_inode(dir_inode) && coda_iscontrol(name, len))
237 return -EPERM;
238
239 symlen = strlen(symname);
240 if (symlen > CODA_MAXPATHLEN)
241 return -ENAMETOOLONG;
242
243 /*
244 * This entry is now negative. Since we do not create
245 * an inode for the entry we have to drop it.
246 */
247 d_drop(de);
248 error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
249 symname, symlen);
250
251 /* mtime is no good anymore */
252 if (!error)
253 coda_dir_update_mtime(dir_inode);
254
255 return error;
256 }
257
258 /* destruction routines: unlink, rmdir */
259 static int coda_unlink(struct inode *dir, struct dentry *de)
260 {
261 int error;
262 const char *name = de->d_name.name;
263 int len = de->d_name.len;
264
265 error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
266 if (error)
267 return error;
268
269 coda_dir_update_mtime(dir);
270 drop_nlink(d_inode(de));
271 return 0;
272 }
273
274 static int coda_rmdir(struct inode *dir, struct dentry *de)
275 {
276 const char *name = de->d_name.name;
277 int len = de->d_name.len;
278 int error;
279
280 error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
281 if (!error) {
282 /* VFS may delete the child */
283 if (d_really_is_positive(de))
284 clear_nlink(d_inode(de));
285
286 /* fix the link count of the parent */
287 coda_dir_drop_nlink(dir);
288 coda_dir_update_mtime(dir);
289 }
290 return error;
291 }
292
293 /* rename */
294 static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
295 struct inode *new_dir, struct dentry *new_dentry,
296 unsigned int flags)
297 {
298 const char *old_name = old_dentry->d_name.name;
299 const char *new_name = new_dentry->d_name.name;
300 int old_length = old_dentry->d_name.len;
301 int new_length = new_dentry->d_name.len;
302 int error;
303
304 if (flags)
305 return -EINVAL;
306
307 error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
308 coda_i2f(new_dir), old_length, new_length,
309 (const char *) old_name, (const char *)new_name);
310 if (!error) {
311 if (d_really_is_positive(new_dentry)) {
312 if (d_is_dir(new_dentry)) {
313 coda_dir_drop_nlink(old_dir);
314 coda_dir_inc_nlink(new_dir);
315 }
316 coda_dir_update_mtime(old_dir);
317 coda_dir_update_mtime(new_dir);
318 coda_flag_inode(d_inode(new_dentry), C_VATTR);
319 } else {
320 coda_flag_inode(old_dir, C_VATTR);
321 coda_flag_inode(new_dir, C_VATTR);
322 }
323 }
324 return error;
325 }
326
327 static inline unsigned int CDT2DT(unsigned char cdt)
328 {
329 unsigned int dt;
330
331 switch(cdt) {
332 case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
333 case CDT_FIFO: dt = DT_FIFO; break;
334 case CDT_CHR: dt = DT_CHR; break;
335 case CDT_DIR: dt = DT_DIR; break;
336 case CDT_BLK: dt = DT_BLK; break;
337 case CDT_REG: dt = DT_REG; break;
338 case CDT_LNK: dt = DT_LNK; break;
339 case CDT_SOCK: dt = DT_SOCK; break;
340 case CDT_WHT: dt = DT_WHT; break;
341 default: dt = DT_UNKNOWN; break;
342 }
343 return dt;
344 }
345
346 /* support routines */
347 static int coda_venus_readdir(struct file *coda_file, struct dir_context *ctx)
348 {
349 struct coda_file_info *cfi;
350 struct coda_inode_info *cii;
351 struct file *host_file;
352 struct venus_dirent *vdir;
353 unsigned long vdir_size = offsetof(struct venus_dirent, d_name);
354 unsigned int type;
355 struct qstr name;
356 ino_t ino;
357 int ret;
358
359 cfi = CODA_FTOC(coda_file);
360 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
361 host_file = cfi->cfi_container;
362
363 cii = ITOC(file_inode(coda_file));
364
365 vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
366 if (!vdir) return -ENOMEM;
367
368 if (!dir_emit_dots(coda_file, ctx))
369 goto out;
370
371 while (1) {
372 loff_t pos = ctx->pos - 2;
373
374 /* read entries from the directory file */
375 ret = kernel_read(host_file, vdir, sizeof(*vdir), &pos);
376 if (ret < 0) {
377 pr_err("%s: read dir %s failed %d\n",
378 __func__, coda_f2s(&cii->c_fid), ret);
379 break;
380 }
381 if (ret == 0) break; /* end of directory file reached */
382
383 /* catch truncated reads */
384 if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) {
385 pr_err("%s: short read on %s\n",
386 __func__, coda_f2s(&cii->c_fid));
387 ret = -EBADF;
388 break;
389 }
390 /* validate whether the directory file actually makes sense */
391 if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
392 pr_err("%s: invalid dir %s\n",
393 __func__, coda_f2s(&cii->c_fid));
394 ret = -EBADF;
395 break;
396 }
397
398 name.len = vdir->d_namlen;
399 name.name = vdir->d_name;
400
401 /* Make sure we skip '.' and '..', we already got those */
402 if (name.name[0] == '.' && (name.len == 1 ||
403 (name.name[1] == '.' && name.len == 2)))
404 vdir->d_fileno = name.len = 0;
405
406 /* skip null entries */
407 if (vdir->d_fileno && name.len) {
408 ino = vdir->d_fileno;
409 type = CDT2DT(vdir->d_type);
410 if (!dir_emit(ctx, name.name, name.len, ino, type))
411 break;
412 }
413 /* we'll always have progress because d_reclen is unsigned and
414 * we've already established it is non-zero. */
415 ctx->pos += vdir->d_reclen;
416 }
417 out:
418 kfree(vdir);
419 return 0;
420 }
421
422 /* file operations for directories */
423 static int coda_readdir(struct file *coda_file, struct dir_context *ctx)
424 {
425 struct coda_file_info *cfi;
426 struct file *host_file;
427 int ret;
428
429 cfi = CODA_FTOC(coda_file);
430 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
431 host_file = cfi->cfi_container;
432
433 if (host_file->f_op->iterate || host_file->f_op->iterate_shared) {
434 struct inode *host_inode = file_inode(host_file);
435 ret = -ENOENT;
436 if (!IS_DEADDIR(host_inode)) {
437 if (host_file->f_op->iterate_shared) {
438 inode_lock_shared(host_inode);
439 ret = host_file->f_op->iterate_shared(host_file, ctx);
440 file_accessed(host_file);
441 inode_unlock_shared(host_inode);
442 } else {
443 inode_lock(host_inode);
444 ret = host_file->f_op->iterate(host_file, ctx);
445 file_accessed(host_file);
446 inode_unlock(host_inode);
447 }
448 }
449 return ret;
450 }
451 /* Venus: we must read Venus dirents from a file */
452 return coda_venus_readdir(coda_file, ctx);
453 }
454
455 /* called when a cache lookup succeeds */
456 static int coda_dentry_revalidate(struct dentry *de, unsigned int flags)
457 {
458 struct inode *inode;
459 struct coda_inode_info *cii;
460
461 if (flags & LOOKUP_RCU)
462 return -ECHILD;
463
464 inode = d_inode(de);
465 if (!inode || is_root_inode(inode))
466 goto out;
467 if (is_bad_inode(inode))
468 goto bad;
469
470 cii = ITOC(d_inode(de));
471 if (!(cii->c_flags & (C_PURGE | C_FLUSH)))
472 goto out;
473
474 shrink_dcache_parent(de);
475
476 /* propagate for a flush */
477 if (cii->c_flags & C_FLUSH)
478 coda_flag_inode_children(inode, C_FLUSH);
479
480 if (d_count(de) > 1)
481 /* pretend it's valid, but don't change the flags */
482 goto out;
483
484 /* clear the flags. */
485 spin_lock(&cii->c_lock);
486 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
487 spin_unlock(&cii->c_lock);
488 bad:
489 return 0;
490 out:
491 return 1;
492 }
493
494 /*
495 * This is the callback from dput() when d_count is going to 0.
496 * We use this to unhash dentries with bad inodes.
497 */
498 static int coda_dentry_delete(const struct dentry * dentry)
499 {
500 int flags;
501
502 if (d_really_is_negative(dentry))
503 return 0;
504
505 flags = (ITOC(d_inode(dentry))->c_flags) & C_PURGE;
506 if (is_bad_inode(d_inode(dentry)) || flags) {
507 return 1;
508 }
509 return 0;
510 }
511
512
513
514 /*
515 * This is called when we want to check if the inode has
516 * changed on the server. Coda makes this easy since the
517 * cache manager Venus issues a downcall to the kernel when this
518 * happens
519 */
520 int coda_revalidate_inode(struct inode *inode)
521 {
522 struct coda_vattr attr;
523 int error;
524 int old_mode;
525 ino_t old_ino;
526 struct coda_inode_info *cii = ITOC(inode);
527
528 if (!cii->c_flags)
529 return 0;
530
531 if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) {
532 error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
533 if (error)
534 return -EIO;
535
536 /* this inode may be lost if:
537 - it's ino changed
538 - type changes must be permitted for repair and
539 missing mount points.
540 */
541 old_mode = inode->i_mode;
542 old_ino = inode->i_ino;
543 coda_vattr_to_iattr(inode, &attr);
544
545 if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
546 pr_warn("inode %ld, fid %s changed type!\n",
547 inode->i_ino, coda_f2s(&(cii->c_fid)));
548 }
549
550 /* the following can happen when a local fid is replaced
551 with a global one, here we lose and declare the inode bad */
552 if (inode->i_ino != old_ino)
553 return -EIO;
554
555 coda_flag_inode_children(inode, C_FLUSH);
556
557 spin_lock(&cii->c_lock);
558 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
559 spin_unlock(&cii->c_lock);
560 }
561 return 0;
562 }
563
564 const struct dentry_operations coda_dentry_operations = {
565 .d_revalidate = coda_dentry_revalidate,
566 .d_delete = coda_dentry_delete,
567 };
568
569 const struct inode_operations coda_dir_inode_operations = {
570 .create = coda_create,
571 .lookup = coda_lookup,
572 .link = coda_link,
573 .unlink = coda_unlink,
574 .symlink = coda_symlink,
575 .mkdir = coda_mkdir,
576 .rmdir = coda_rmdir,
577 .mknod = CODA_EIO_ERROR,
578 .rename = coda_rename,
579 .permission = coda_permission,
580 .getattr = coda_getattr,
581 .setattr = coda_setattr,
582 };
583
584 const struct file_operations coda_dir_operations = {
585 .llseek = generic_file_llseek,
586 .read = generic_read_dir,
587 .iterate = coda_readdir,
588 .open = coda_open,
589 .release = coda_release,
590 .fsync = coda_fsync,
591 };
Linux with added FPC-III support