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scsi: hisi_sas: modify return value of hisi_sas_query_task()
[linux/fpc-iii.git] / fs / coda / dir.c
blobc0474ac6cbf200eb458eaf5e3f2359e9b0edfcab
1
2 /*
3 * Directory operations for Coda filesystem
4 * Original version: (C) 1996 P. Braam and M. Callahan
5 * Rewritten for Linux 2.1. (C) 1997 Carnegie Mellon University
6 *
7 * Carnegie Mellon encourages users to contribute improvements to
8 * the Coda project. Contact Peter Braam (coda@cs.cmu.edu).
9 */
10
11 #include <linux/types.h>
12 #include <linux/kernel.h>
13 #include <linux/time.h>
14 #include <linux/fs.h>
15 #include <linux/slab.h>
16 #include <linux/file.h>
17 #include <linux/stat.h>
18 #include <linux/errno.h>
19 #include <linux/string.h>
20 #include <linux/spinlock.h>
21 #include <linux/namei.h>
22 #include <linux/uaccess.h>
23
24 #include <linux/coda.h>
25 #include <linux/coda_psdev.h>
26 #include "coda_linux.h"
27 #include "coda_cache.h"
28
29 #include "coda_int.h"
30
31 /* same as fs/bad_inode.c */
32 static int coda_return_EIO(void)
33 {
34 return -EIO;
35 }
36 #define CODA_EIO_ERROR ((void *) (coda_return_EIO))
37
38 /* inode operations for directories */
39 /* access routines: lookup, readlink, permission */
40 static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, unsigned int flags)
41 {
42 struct super_block *sb = dir->i_sb;
43 const char *name = entry->d_name.name;
44 size_t length = entry->d_name.len;
45 struct inode *inode;
46 int type = 0;
47
48 if (length > CODA_MAXNAMLEN) {
49 pr_err("name too long: lookup, %s (%*s)\n",
50 coda_i2s(dir), (int)length, name);
51 return ERR_PTR(-ENAMETOOLONG);
52 }
53
54 /* control object, create inode on the fly */
55 if (is_root_inode(dir) && coda_iscontrol(name, length)) {
56 inode = coda_cnode_makectl(sb);
57 type = CODA_NOCACHE;
58 } else {
59 struct CodaFid fid = { { 0, } };
60 int error = venus_lookup(sb, coda_i2f(dir), name, length,
61 &type, &fid);
62 inode = !error ? coda_cnode_make(&fid, sb) : ERR_PTR(error);
63 }
64
65 if (!IS_ERR(inode) && (type & CODA_NOCACHE))
66 coda_flag_inode(inode, C_VATTR | C_PURGE);
67
68 if (inode == ERR_PTR(-ENOENT))
69 inode = NULL;
70
71 return d_splice_alias(inode, entry);
72 }
73
74
75 int coda_permission(struct inode *inode, int mask)
76 {
77 int error;
78
79 if (mask & MAY_NOT_BLOCK)
80 return -ECHILD;
81
82 mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
83
84 if (!mask)
85 return 0;
86
87 if ((mask & MAY_EXEC) && !execute_ok(inode))
88 return -EACCES;
89
90 if (coda_cache_check(inode, mask))
91 return 0;
92
93 error = venus_access(inode->i_sb, coda_i2f(inode), mask);
94
95 if (!error)
96 coda_cache_enter(inode, mask);
97
98 return error;
99 }
100
101
102 static inline void coda_dir_update_mtime(struct inode *dir)
103 {
104 #ifdef REQUERY_VENUS_FOR_MTIME
105 /* invalidate the directory cnode's attributes so we refetch the
106 * attributes from venus next time the inode is referenced */
107 coda_flag_inode(dir, C_VATTR);
108 #else
109 /* optimistically we can also act as if our nose bleeds. The
110 * granularity of the mtime is coarse anyways so we might actually be
111 * right most of the time. Note: we only do this for directories. */
112 dir->i_mtime = dir->i_ctime = current_time(dir);
113 #endif
114 }
115
116 /* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
117 * trick to fool GNU find's optimizations. If we can't be sure of the link
118 * (because of volume mount points) we set i_nlink to 1 which forces find
119 * to consider every child as a possible directory. We should also never
120 * see an increment or decrement for deleted directories where i_nlink == 0 */
121 static inline void coda_dir_inc_nlink(struct inode *dir)
122 {
123 if (dir->i_nlink >= 2)
124 inc_nlink(dir);
125 }
126
127 static inline void coda_dir_drop_nlink(struct inode *dir)
128 {
129 if (dir->i_nlink > 2)
130 drop_nlink(dir);
131 }
132
133 /* creation routines: create, mknod, mkdir, link, symlink */
134 static int coda_create(struct inode *dir, struct dentry *de, umode_t mode, bool excl)
135 {
136 int error;
137 const char *name=de->d_name.name;
138 int length=de->d_name.len;
139 struct inode *inode;
140 struct CodaFid newfid;
141 struct coda_vattr attrs;
142
143 if (is_root_inode(dir) && coda_iscontrol(name, length))
144 return -EPERM;
145
146 error = venus_create(dir->i_sb, coda_i2f(dir), name, length,
147 0, mode, &newfid, &attrs);
148 if (error)
149 goto err_out;
150
151 inode = coda_iget(dir->i_sb, &newfid, &attrs);
152 if (IS_ERR(inode)) {
153 error = PTR_ERR(inode);
154 goto err_out;
155 }
156
157 /* invalidate the directory cnode's attributes */
158 coda_dir_update_mtime(dir);
159 d_instantiate(de, inode);
160 return 0;
161 err_out:
162 d_drop(de);
163 return error;
164 }
165
166 static int coda_mkdir(struct inode *dir, struct dentry *de, umode_t mode)
167 {
168 struct inode *inode;
169 struct coda_vattr attrs;
170 const char *name = de->d_name.name;
171 int len = de->d_name.len;
172 int error;
173 struct CodaFid newfid;
174
175 if (is_root_inode(dir) && coda_iscontrol(name, len))
176 return -EPERM;
177
178 attrs.va_mode = mode;
179 error = venus_mkdir(dir->i_sb, coda_i2f(dir),
180 name, len, &newfid, &attrs);
181 if (error)
182 goto err_out;
183
184 inode = coda_iget(dir->i_sb, &newfid, &attrs);
185 if (IS_ERR(inode)) {
186 error = PTR_ERR(inode);
187 goto err_out;
188 }
189
190 /* invalidate the directory cnode's attributes */
191 coda_dir_inc_nlink(dir);
192 coda_dir_update_mtime(dir);
193 d_instantiate(de, inode);
194 return 0;
195 err_out:
196 d_drop(de);
197 return error;
198 }
199
200 /* try to make de an entry in dir_inodde linked to source_de */
201 static int coda_link(struct dentry *source_de, struct inode *dir_inode,
202 struct dentry *de)
203 {
204 struct inode *inode = d_inode(source_de);
205 const char * name = de->d_name.name;
206 int len = de->d_name.len;
207 int error;
208
209 if (is_root_inode(dir_inode) && coda_iscontrol(name, len))
210 return -EPERM;
211
212 error = venus_link(dir_inode->i_sb, coda_i2f(inode),
213 coda_i2f(dir_inode), (const char *)name, len);
214 if (error) {
215 d_drop(de);
216 return error;
217 }
218
219 coda_dir_update_mtime(dir_inode);
220 ihold(inode);
221 d_instantiate(de, inode);
222 inc_nlink(inode);
223 return 0;
224 }
225
226
227 static int coda_symlink(struct inode *dir_inode, struct dentry *de,
228 const char *symname)
229 {
230 const char *name = de->d_name.name;
231 int len = de->d_name.len;
232 int symlen;
233 int error;
234
235 if (is_root_inode(dir_inode) && coda_iscontrol(name, len))
236 return -EPERM;
237
238 symlen = strlen(symname);
239 if (symlen > CODA_MAXPATHLEN)
240 return -ENAMETOOLONG;
241
242 /*
243 * This entry is now negative. Since we do not create
244 * an inode for the entry we have to drop it.
245 */
246 d_drop(de);
247 error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
248 symname, symlen);
249
250 /* mtime is no good anymore */
251 if (!error)
252 coda_dir_update_mtime(dir_inode);
253
254 return error;
255 }
256
257 /* destruction routines: unlink, rmdir */
258 static int coda_unlink(struct inode *dir, struct dentry *de)
259 {
260 int error;
261 const char *name = de->d_name.name;
262 int len = de->d_name.len;
263
264 error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
265 if (error)
266 return error;
267
268 coda_dir_update_mtime(dir);
269 drop_nlink(d_inode(de));
270 return 0;
271 }
272
273 static int coda_rmdir(struct inode *dir, struct dentry *de)
274 {
275 const char *name = de->d_name.name;
276 int len = de->d_name.len;
277 int error;
278
279 error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
280 if (!error) {
281 /* VFS may delete the child */
282 if (d_really_is_positive(de))
283 clear_nlink(d_inode(de));
284
285 /* fix the link count of the parent */
286 coda_dir_drop_nlink(dir);
287 coda_dir_update_mtime(dir);
288 }
289 return error;
290 }
291
292 /* rename */
293 static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
294 struct inode *new_dir, struct dentry *new_dentry,
295 unsigned int flags)
296 {
297 const char *old_name = old_dentry->d_name.name;
298 const char *new_name = new_dentry->d_name.name;
299 int old_length = old_dentry->d_name.len;
300 int new_length = new_dentry->d_name.len;
301 int error;
302
303 if (flags)
304 return -EINVAL;
305
306 error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
307 coda_i2f(new_dir), old_length, new_length,
308 (const char *) old_name, (const char *)new_name);
309 if (!error) {
310 if (d_really_is_positive(new_dentry)) {
311 if (d_is_dir(new_dentry)) {
312 coda_dir_drop_nlink(old_dir);
313 coda_dir_inc_nlink(new_dir);
314 }
315 coda_dir_update_mtime(old_dir);
316 coda_dir_update_mtime(new_dir);
317 coda_flag_inode(d_inode(new_dentry), C_VATTR);
318 } else {
319 coda_flag_inode(old_dir, C_VATTR);
320 coda_flag_inode(new_dir, C_VATTR);
321 }
322 }
323 return error;
324 }
325
326 static inline unsigned int CDT2DT(unsigned char cdt)
327 {
328 unsigned int dt;
329
330 switch(cdt) {
331 case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
332 case CDT_FIFO: dt = DT_FIFO; break;
333 case CDT_CHR: dt = DT_CHR; break;
334 case CDT_DIR: dt = DT_DIR; break;
335 case CDT_BLK: dt = DT_BLK; break;
336 case CDT_REG: dt = DT_REG; break;
337 case CDT_LNK: dt = DT_LNK; break;
338 case CDT_SOCK: dt = DT_SOCK; break;
339 case CDT_WHT: dt = DT_WHT; break;
340 default: dt = DT_UNKNOWN; break;
341 }
342 return dt;
343 }
344
345 /* support routines */
346 static int coda_venus_readdir(struct file *coda_file, struct dir_context *ctx)
347 {
348 struct coda_file_info *cfi;
349 struct coda_inode_info *cii;
350 struct file *host_file;
351 struct venus_dirent *vdir;
352 unsigned long vdir_size = offsetof(struct venus_dirent, d_name);
353 unsigned int type;
354 struct qstr name;
355 ino_t ino;
356 int ret;
357
358 cfi = CODA_FTOC(coda_file);
359 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
360 host_file = cfi->cfi_container;
361
362 cii = ITOC(file_inode(coda_file));
363
364 vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
365 if (!vdir) return -ENOMEM;
366
367 if (!dir_emit_dots(coda_file, ctx))
368 goto out;
369
370 while (1) {
371 /* read entries from the directory file */
372 ret = kernel_read(host_file, ctx->pos - 2, (char *)vdir,
373 sizeof(*vdir));
374 if (ret < 0) {
375 pr_err("%s: read dir %s failed %d\n",
376 __func__, coda_f2s(&cii->c_fid), ret);
377 break;
378 }
379 if (ret == 0) break; /* end of directory file reached */
380
381 /* catch truncated reads */
382 if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) {
383 pr_err("%s: short read on %s\n",
384 __func__, coda_f2s(&cii->c_fid));
385 ret = -EBADF;
386 break;
387 }
388 /* validate whether the directory file actually makes sense */
389 if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
390 pr_err("%s: invalid dir %s\n",
391 __func__, coda_f2s(&cii->c_fid));
392 ret = -EBADF;
393 break;
394 }
395
396 name.len = vdir->d_namlen;
397 name.name = vdir->d_name;
398
399 /* Make sure we skip '.' and '..', we already got those */
400 if (name.name[0] == '.' && (name.len == 1 ||
401 (name.name[1] == '.' && name.len == 2)))
402 vdir->d_fileno = name.len = 0;
403
404 /* skip null entries */
405 if (vdir->d_fileno && name.len) {
406 ino = vdir->d_fileno;
407 type = CDT2DT(vdir->d_type);
408 if (!dir_emit(ctx, name.name, name.len, ino, type))
409 break;
410 }
411 /* we'll always have progress because d_reclen is unsigned and
412 * we've already established it is non-zero. */
413 ctx->pos += vdir->d_reclen;
414 }
415 out:
416 kfree(vdir);
417 return 0;
418 }
419
420 /* file operations for directories */
421 static int coda_readdir(struct file *coda_file, struct dir_context *ctx)
422 {
423 struct coda_file_info *cfi;
424 struct file *host_file;
425 int ret;
426
427 cfi = CODA_FTOC(coda_file);
428 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
429 host_file = cfi->cfi_container;
430
431 if (host_file->f_op->iterate || host_file->f_op->iterate_shared) {
432 struct inode *host_inode = file_inode(host_file);
433 ret = -ENOENT;
434 if (!IS_DEADDIR(host_inode)) {
435 if (host_file->f_op->iterate_shared) {
436 inode_lock_shared(host_inode);
437 ret = host_file->f_op->iterate_shared(host_file, ctx);
438 file_accessed(host_file);
439 inode_unlock_shared(host_inode);
440 } else {
441 inode_lock(host_inode);
442 ret = host_file->f_op->iterate(host_file, ctx);
443 file_accessed(host_file);
444 inode_unlock(host_inode);
445 }
446 }
447 return ret;
448 }
449 /* Venus: we must read Venus dirents from a file */
450 return coda_venus_readdir(coda_file, ctx);
451 }
452
453 /* called when a cache lookup succeeds */
454 static int coda_dentry_revalidate(struct dentry *de, unsigned int flags)
455 {
456 struct inode *inode;
457 struct coda_inode_info *cii;
458
459 if (flags & LOOKUP_RCU)
460 return -ECHILD;
461
462 inode = d_inode(de);
463 if (!inode || is_root_inode(inode))
464 goto out;
465 if (is_bad_inode(inode))
466 goto bad;
467
468 cii = ITOC(d_inode(de));
469 if (!(cii->c_flags & (C_PURGE | C_FLUSH)))
470 goto out;
471
472 shrink_dcache_parent(de);
473
474 /* propagate for a flush */
475 if (cii->c_flags & C_FLUSH)
476 coda_flag_inode_children(inode, C_FLUSH);
477
478 if (d_count(de) > 1)
479 /* pretend it's valid, but don't change the flags */
480 goto out;
481
482 /* clear the flags. */
483 spin_lock(&cii->c_lock);
484 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
485 spin_unlock(&cii->c_lock);
486 bad:
487 return 0;
488 out:
489 return 1;
490 }
491
492 /*
493 * This is the callback from dput() when d_count is going to 0.
494 * We use this to unhash dentries with bad inodes.
495 */
496 static int coda_dentry_delete(const struct dentry * dentry)
497 {
498 int flags;
499
500 if (d_really_is_negative(dentry))
501 return 0;
502
503 flags = (ITOC(d_inode(dentry))->c_flags) & C_PURGE;
504 if (is_bad_inode(d_inode(dentry)) || flags) {
505 return 1;
506 }
507 return 0;
508 }
509
510
511
512 /*
513 * This is called when we want to check if the inode has
514 * changed on the server. Coda makes this easy since the
515 * cache manager Venus issues a downcall to the kernel when this
516 * happens
517 */
518 int coda_revalidate_inode(struct inode *inode)
519 {
520 struct coda_vattr attr;
521 int error;
522 int old_mode;
523 ino_t old_ino;
524 struct coda_inode_info *cii = ITOC(inode);
525
526 if (!cii->c_flags)
527 return 0;
528
529 if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) {
530 error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
531 if (error)
532 return -EIO;
533
534 /* this inode may be lost if:
535 - it's ino changed
536 - type changes must be permitted for repair and
537 missing mount points.
538 */
539 old_mode = inode->i_mode;
540 old_ino = inode->i_ino;
541 coda_vattr_to_iattr(inode, &attr);
542
543 if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
544 pr_warn("inode %ld, fid %s changed type!\n",
545 inode->i_ino, coda_f2s(&(cii->c_fid)));
546 }
547
548 /* the following can happen when a local fid is replaced
549 with a global one, here we lose and declare the inode bad */
550 if (inode->i_ino != old_ino)
551 return -EIO;
552
553 coda_flag_inode_children(inode, C_FLUSH);
554
555 spin_lock(&cii->c_lock);
556 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
557 spin_unlock(&cii->c_lock);
558 }
559 return 0;
560 }
561
562 const struct dentry_operations coda_dentry_operations = {
563 .d_revalidate = coda_dentry_revalidate,
564 .d_delete = coda_dentry_delete,
565 };
566
567 const struct inode_operations coda_dir_inode_operations = {
568 .create = coda_create,
569 .lookup = coda_lookup,
570 .link = coda_link,
571 .unlink = coda_unlink,
572 .symlink = coda_symlink,
573 .mkdir = coda_mkdir,
574 .rmdir = coda_rmdir,
575 .mknod = CODA_EIO_ERROR,
576 .rename = coda_rename,
577 .permission = coda_permission,
578 .getattr = coda_getattr,
579 .setattr = coda_setattr,
580 };
581
582 const struct file_operations coda_dir_operations = {
583 .llseek = generic_file_llseek,
584 .read = generic_read_dir,
585 .iterate = coda_readdir,
586 .open = coda_open,
587 .release = coda_release,
588 .fsync = coda_fsync,
589 };
Linux with added FPC-III support