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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
23#include <asm/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/* dir inode-ops */
33static int coda_create(struct inode *dir, struct dentry *new, umode_t mode, struct nameidata *nd);
34static struct dentry *coda_lookup(struct inode *dir, struct dentry *target, struct nameidata *nd);
35static int coda_link(struct dentry *old_dentry, struct inode *dir_inode,
36 struct dentry *entry);
37static int coda_unlink(struct inode *dir_inode, struct dentry *entry);
38static int coda_symlink(struct inode *dir_inode, struct dentry *entry,
39 const char *symname);
40static int coda_mkdir(struct inode *dir_inode, struct dentry *entry, umode_t mode);
41static int coda_rmdir(struct inode *dir_inode, struct dentry *entry);
42static int coda_rename(struct inode *old_inode, struct dentry *old_dentry,
43 struct inode *new_inode, struct dentry *new_dentry);
44
45/* dir file-ops */
46static int coda_readdir(struct file *file, void *buf, filldir_t filldir);
47
48/* dentry ops */
49static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd);
50static int coda_dentry_delete(const struct dentry *);
51
52/* support routines */
53static int coda_venus_readdir(struct file *coda_file, void *buf,
54 filldir_t filldir);
55
56/* same as fs/bad_inode.c */
57static int coda_return_EIO(void)
58{
59 return -EIO;
60}
61#define CODA_EIO_ERROR ((void *) (coda_return_EIO))
62
63const struct dentry_operations coda_dentry_operations =
64{
65 .d_revalidate = coda_dentry_revalidate,
66 .d_delete = coda_dentry_delete,
67};
68
69const struct inode_operations coda_dir_inode_operations =
70{
71 .create = coda_create,
72 .lookup = coda_lookup,
73 .link = coda_link,
74 .unlink = coda_unlink,
75 .symlink = coda_symlink,
76 .mkdir = coda_mkdir,
77 .rmdir = coda_rmdir,
78 .mknod = CODA_EIO_ERROR,
79 .rename = coda_rename,
80 .permission = coda_permission,
81 .getattr = coda_getattr,
82 .setattr = coda_setattr,
83};
84
85const struct file_operations coda_dir_operations = {
86 .llseek = generic_file_llseek,
87 .read = generic_read_dir,
88 .readdir = coda_readdir,
89 .open = coda_open,
90 .release = coda_release,
91 .fsync = coda_fsync,
92};
93
94
95/* inode operations for directories */
96/* access routines: lookup, readlink, permission */
97static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, struct nameidata *nd)
98{
99 struct super_block *sb = dir->i_sb;
100 const char *name = entry->d_name.name;
101 size_t length = entry->d_name.len;
102 struct inode *inode;
103 int type = 0;
104
105 if (length > CODA_MAXNAMLEN) {
106 printk(KERN_ERR "name too long: lookup, %s (%*s)\n",
107 coda_i2s(dir), (int)length, name);
108 return ERR_PTR(-ENAMETOOLONG);
109 }
110
111 /* control object, create inode on the fly */
112 if (coda_isroot(dir) && coda_iscontrol(name, length)) {
113 inode = coda_cnode_makectl(sb);
114 type = CODA_NOCACHE;
115 } else {
116 struct CodaFid fid = { { 0, } };
117 int error = venus_lookup(sb, coda_i2f(dir), name, length,
118 &type, &fid);
119 inode = !error ? coda_cnode_make(&fid, sb) : ERR_PTR(error);
120 }
121
122 if (!IS_ERR(inode) && (type & CODA_NOCACHE))
123 coda_flag_inode(inode, C_VATTR | C_PURGE);
124
125 if (inode == ERR_PTR(-ENOENT))
126 inode = NULL;
127
128 return d_splice_alias(inode, entry);
129}
130
131
132int coda_permission(struct inode *inode, int mask)
133{
134 int error;
135
136 if (mask & MAY_NOT_BLOCK)
137 return -ECHILD;
138
139 mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
140
141 if (!mask)
142 return 0;
143
144 if ((mask & MAY_EXEC) && !execute_ok(inode))
145 return -EACCES;
146
147 if (coda_cache_check(inode, mask))
148 return 0;
149
150 error = venus_access(inode->i_sb, coda_i2f(inode), mask);
151
152 if (!error)
153 coda_cache_enter(inode, mask);
154
155 return error;
156}
157
158
159static inline void coda_dir_update_mtime(struct inode *dir)
160{
161#ifdef REQUERY_VENUS_FOR_MTIME
162 /* invalidate the directory cnode's attributes so we refetch the
163 * attributes from venus next time the inode is referenced */
164 coda_flag_inode(dir, C_VATTR);
165#else
166 /* optimistically we can also act as if our nose bleeds. The
167 * granularity of the mtime is coarse anyways so we might actually be
168 * right most of the time. Note: we only do this for directories. */
169 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
170#endif
171}
172
173/* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
174 * trick to fool GNU find's optimizations. If we can't be sure of the link
175 * (because of volume mount points) we set i_nlink to 1 which forces find
176 * to consider every child as a possible directory. We should also never
177 * see an increment or decrement for deleted directories where i_nlink == 0 */
178static inline void coda_dir_inc_nlink(struct inode *dir)
179{
180 if (dir->i_nlink >= 2)
181 inc_nlink(dir);
182}
183
184static inline void coda_dir_drop_nlink(struct inode *dir)
185{
186 if (dir->i_nlink > 2)
187 drop_nlink(dir);
188}
189
190/* creation routines: create, mknod, mkdir, link, symlink */
191static int coda_create(struct inode *dir, struct dentry *de, umode_t mode, struct nameidata *nd)
192{
193 int error;
194 const char *name=de->d_name.name;
195 int length=de->d_name.len;
196 struct inode *inode;
197 struct CodaFid newfid;
198 struct coda_vattr attrs;
199
200 if (coda_isroot(dir) && coda_iscontrol(name, length))
201 return -EPERM;
202
203 error = venus_create(dir->i_sb, coda_i2f(dir), name, length,
204 0, mode, &newfid, &attrs);
205 if (error)
206 goto err_out;
207
208 inode = coda_iget(dir->i_sb, &newfid, &attrs);
209 if (IS_ERR(inode)) {
210 error = PTR_ERR(inode);
211 goto err_out;
212 }
213
214 /* invalidate the directory cnode's attributes */
215 coda_dir_update_mtime(dir);
216 d_instantiate(de, inode);
217 return 0;
218err_out:
219 d_drop(de);
220 return error;
221}
222
223static int coda_mkdir(struct inode *dir, struct dentry *de, umode_t mode)
224{
225 struct inode *inode;
226 struct coda_vattr attrs;
227 const char *name = de->d_name.name;
228 int len = de->d_name.len;
229 int error;
230 struct CodaFid newfid;
231
232 if (coda_isroot(dir) && coda_iscontrol(name, len))
233 return -EPERM;
234
235 attrs.va_mode = mode;
236 error = venus_mkdir(dir->i_sb, coda_i2f(dir),
237 name, len, &newfid, &attrs);
238 if (error)
239 goto err_out;
240
241 inode = coda_iget(dir->i_sb, &newfid, &attrs);
242 if (IS_ERR(inode)) {
243 error = PTR_ERR(inode);
244 goto err_out;
245 }
246
247 /* invalidate the directory cnode's attributes */
248 coda_dir_inc_nlink(dir);
249 coda_dir_update_mtime(dir);
250 d_instantiate(de, inode);
251 return 0;
252err_out:
253 d_drop(de);
254 return error;
255}
256
257/* try to make de an entry in dir_inodde linked to source_de */
258static int coda_link(struct dentry *source_de, struct inode *dir_inode,
259 struct dentry *de)
260{
261 struct inode *inode = source_de->d_inode;
262 const char * name = de->d_name.name;
263 int len = de->d_name.len;
264 int error;
265
266 if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
267 return -EPERM;
268
269 error = venus_link(dir_inode->i_sb, coda_i2f(inode),
270 coda_i2f(dir_inode), (const char *)name, len);
271 if (error) {
272 d_drop(de);
273 return error;
274 }
275
276 coda_dir_update_mtime(dir_inode);
277 ihold(inode);
278 d_instantiate(de, inode);
279 inc_nlink(inode);
280 return 0;
281}
282
283
284static int coda_symlink(struct inode *dir_inode, struct dentry *de,
285 const char *symname)
286{
287 const char *name = de->d_name.name;
288 int len = de->d_name.len;
289 int symlen;
290 int error;
291
292 if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
293 return -EPERM;
294
295 symlen = strlen(symname);
296 if (symlen > CODA_MAXPATHLEN)
297 return -ENAMETOOLONG;
298
299 /*
300 * This entry is now negative. Since we do not create
301 * an inode for the entry we have to drop it.
302 */
303 d_drop(de);
304 error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
305 symname, symlen);
306
307 /* mtime is no good anymore */
308 if (!error)
309 coda_dir_update_mtime(dir_inode);
310
311 return error;
312}
313
314/* destruction routines: unlink, rmdir */
315static int coda_unlink(struct inode *dir, struct dentry *de)
316{
317 int error;
318 const char *name = de->d_name.name;
319 int len = de->d_name.len;
320
321 error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
322 if (error)
323 return error;
324
325 coda_dir_update_mtime(dir);
326 drop_nlink(de->d_inode);
327 return 0;
328}
329
330static int coda_rmdir(struct inode *dir, struct dentry *de)
331{
332 const char *name = de->d_name.name;
333 int len = de->d_name.len;
334 int error;
335
336 error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
337 if (!error) {
338 /* VFS may delete the child */
339 if (de->d_inode)
340 clear_nlink(de->d_inode);
341
342 /* fix the link count of the parent */
343 coda_dir_drop_nlink(dir);
344 coda_dir_update_mtime(dir);
345 }
346 return error;
347}
348
349/* rename */
350static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
351 struct inode *new_dir, struct dentry *new_dentry)
352{
353 const char *old_name = old_dentry->d_name.name;
354 const char *new_name = new_dentry->d_name.name;
355 int old_length = old_dentry->d_name.len;
356 int new_length = new_dentry->d_name.len;
357 int error;
358
359 error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
360 coda_i2f(new_dir), old_length, new_length,
361 (const char *) old_name, (const char *)new_name);
362 if (!error) {
363 if (new_dentry->d_inode) {
364 if (S_ISDIR(new_dentry->d_inode->i_mode)) {
365 coda_dir_drop_nlink(old_dir);
366 coda_dir_inc_nlink(new_dir);
367 }
368 coda_dir_update_mtime(old_dir);
369 coda_dir_update_mtime(new_dir);
370 coda_flag_inode(new_dentry->d_inode, C_VATTR);
371 } else {
372 coda_flag_inode(old_dir, C_VATTR);
373 coda_flag_inode(new_dir, C_VATTR);
374 }
375 }
376 return error;
377}
378
379
380/* file operations for directories */
381static int coda_readdir(struct file *coda_file, void *buf, filldir_t filldir)
382{
383 struct coda_file_info *cfi;
384 struct file *host_file;
385 int ret;
386
387 cfi = CODA_FTOC(coda_file);
388 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
389 host_file = cfi->cfi_container;
390
391 if (!host_file->f_op)
392 return -ENOTDIR;
393
394 if (host_file->f_op->readdir)
395 {
396 /* potemkin case: we were handed a directory inode.
397 * We can't use vfs_readdir because we have to keep the file
398 * position in sync between the coda_file and the host_file.
399 * and as such we need grab the inode mutex. */
400 struct inode *host_inode = host_file->f_path.dentry->d_inode;
401
402 mutex_lock(&host_inode->i_mutex);
403 host_file->f_pos = coda_file->f_pos;
404
405 ret = -ENOENT;
406 if (!IS_DEADDIR(host_inode)) {
407 ret = host_file->f_op->readdir(host_file, buf, filldir);
408 file_accessed(host_file);
409 }
410
411 coda_file->f_pos = host_file->f_pos;
412 mutex_unlock(&host_inode->i_mutex);
413 }
414 else /* Venus: we must read Venus dirents from a file */
415 ret = coda_venus_readdir(coda_file, buf, filldir);
416
417 return ret;
418}
419
420static inline unsigned int CDT2DT(unsigned char cdt)
421{
422 unsigned int dt;
423
424 switch(cdt) {
425 case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
426 case CDT_FIFO: dt = DT_FIFO; break;
427 case CDT_CHR: dt = DT_CHR; break;
428 case CDT_DIR: dt = DT_DIR; break;
429 case CDT_BLK: dt = DT_BLK; break;
430 case CDT_REG: dt = DT_REG; break;
431 case CDT_LNK: dt = DT_LNK; break;
432 case CDT_SOCK: dt = DT_SOCK; break;
433 case CDT_WHT: dt = DT_WHT; break;
434 default: dt = DT_UNKNOWN; break;
435 }
436 return dt;
437}
438
439/* support routines */
440static int coda_venus_readdir(struct file *coda_file, void *buf,
441 filldir_t filldir)
442{
443 int result = 0; /* # of entries returned */
444 struct coda_file_info *cfi;
445 struct coda_inode_info *cii;
446 struct file *host_file;
447 struct dentry *de;
448 struct venus_dirent *vdir;
449 unsigned long vdir_size = offsetof(struct venus_dirent, d_name);
450 unsigned int type;
451 struct qstr name;
452 ino_t ino;
453 int ret;
454
455 cfi = CODA_FTOC(coda_file);
456 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
457 host_file = cfi->cfi_container;
458
459 de = coda_file->f_path.dentry;
460 cii = ITOC(de->d_inode);
461
462 vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
463 if (!vdir) return -ENOMEM;
464
465 if (coda_file->f_pos == 0) {
466 ret = filldir(buf, ".", 1, 0, de->d_inode->i_ino, DT_DIR);
467 if (ret < 0)
468 goto out;
469 result++;
470 coda_file->f_pos++;
471 }
472 if (coda_file->f_pos == 1) {
473 ret = filldir(buf, "..", 2, 1, parent_ino(de), DT_DIR);
474 if (ret < 0)
475 goto out;
476 result++;
477 coda_file->f_pos++;
478 }
479 while (1) {
480 /* read entries from the directory file */
481 ret = kernel_read(host_file, coda_file->f_pos - 2, (char *)vdir,
482 sizeof(*vdir));
483 if (ret < 0) {
484 printk(KERN_ERR "coda readdir: read dir %s failed %d\n",
485 coda_f2s(&cii->c_fid), ret);
486 break;
487 }
488 if (ret == 0) break; /* end of directory file reached */
489
490 /* catch truncated reads */
491 if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) {
492 printk(KERN_ERR "coda readdir: short read on %s\n",
493 coda_f2s(&cii->c_fid));
494 ret = -EBADF;
495 break;
496 }
497 /* validate whether the directory file actually makes sense */
498 if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
499 printk(KERN_ERR "coda readdir: invalid dir %s\n",
500 coda_f2s(&cii->c_fid));
501 ret = -EBADF;
502 break;
503 }
504
505 name.len = vdir->d_namlen;
506 name.name = vdir->d_name;
507
508 /* Make sure we skip '.' and '..', we already got those */
509 if (name.name[0] == '.' && (name.len == 1 ||
510 (vdir->d_name[1] == '.' && name.len == 2)))
511 vdir->d_fileno = name.len = 0;
512
513 /* skip null entries */
514 if (vdir->d_fileno && name.len) {
515 /* try to look up this entry in the dcache, that way
516 * userspace doesn't have to worry about breaking
517 * getcwd by having mismatched inode numbers for
518 * internal volume mountpoints. */
519 ino = find_inode_number(de, &name);
520 if (!ino) ino = vdir->d_fileno;
521
522 type = CDT2DT(vdir->d_type);
523 ret = filldir(buf, name.name, name.len,
524 coda_file->f_pos, ino, type);
525 /* failure means no space for filling in this round */
526 if (ret < 0) break;
527 result++;
528 }
529 /* we'll always have progress because d_reclen is unsigned and
530 * we've already established it is non-zero. */
531 coda_file->f_pos += vdir->d_reclen;
532 }
533out:
534 kfree(vdir);
535 return result ? result : ret;
536}
537
538/* called when a cache lookup succeeds */
539static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd)
540{
541 struct inode *inode;
542 struct coda_inode_info *cii;
543
544 if (nd->flags & LOOKUP_RCU)
545 return -ECHILD;
546
547 inode = de->d_inode;
548 if (!inode || coda_isroot(inode))
549 goto out;
550 if (is_bad_inode(inode))
551 goto bad;
552
553 cii = ITOC(de->d_inode);
554 if (!(cii->c_flags & (C_PURGE | C_FLUSH)))
555 goto out;
556
557 shrink_dcache_parent(de);
558
559 /* propagate for a flush */
560 if (cii->c_flags & C_FLUSH)
561 coda_flag_inode_children(inode, C_FLUSH);
562
563 if (de->d_count > 1)
564 /* pretend it's valid, but don't change the flags */
565 goto out;
566
567 /* clear the flags. */
568 spin_lock(&cii->c_lock);
569 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
570 spin_unlock(&cii->c_lock);
571bad:
572 return 0;
573out:
574 return 1;
575}
576
577/*
578 * This is the callback from dput() when d_count is going to 0.
579 * We use this to unhash dentries with bad inodes.
580 */
581static int coda_dentry_delete(const struct dentry * dentry)
582{
583 int flags;
584
585 if (!dentry->d_inode)
586 return 0;
587
588 flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE;
589 if (is_bad_inode(dentry->d_inode) || flags) {
590 return 1;
591 }
592 return 0;
593}
594
595
596
597/*
598 * This is called when we want to check if the inode has
599 * changed on the server. Coda makes this easy since the
600 * cache manager Venus issues a downcall to the kernel when this
601 * happens
602 */
603int coda_revalidate_inode(struct dentry *dentry)
604{
605 struct coda_vattr attr;
606 int error;
607 int old_mode;
608 ino_t old_ino;
609 struct inode *inode = dentry->d_inode;
610 struct coda_inode_info *cii = ITOC(inode);
611
612 if (!cii->c_flags)
613 return 0;
614
615 if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) {
616 error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
617 if (error)
618 return -EIO;
619
620 /* this inode may be lost if:
621 - it's ino changed
622 - type changes must be permitted for repair and
623 missing mount points.
624 */
625 old_mode = inode->i_mode;
626 old_ino = inode->i_ino;
627 coda_vattr_to_iattr(inode, &attr);
628
629 if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
630 printk("Coda: inode %ld, fid %s changed type!\n",
631 inode->i_ino, coda_f2s(&(cii->c_fid)));
632 }
633
634 /* the following can happen when a local fid is replaced
635 with a global one, here we lose and declare the inode bad */
636 if (inode->i_ino != old_ino)
637 return -EIO;
638
639 coda_flag_inode_children(inode, C_FLUSH);
640
641 spin_lock(&cii->c_lock);
642 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
643 spin_unlock(&cii->c_lock);
644 }
645 return 0;
646}
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 "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 */
33static 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 */
41static 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 %zu\n",
51 coda_i2s(dir), length);
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
76int coda_permission(struct user_namespace *mnt_userns, struct inode *inode,
77 int mask)
78{
79 int error;
80
81 if (mask & MAY_NOT_BLOCK)
82 return -ECHILD;
83
84 mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
85
86 if (!mask)
87 return 0;
88
89 if ((mask & MAY_EXEC) && !execute_ok(inode))
90 return -EACCES;
91
92 if (coda_cache_check(inode, mask))
93 return 0;
94
95 error = venus_access(inode->i_sb, coda_i2f(inode), mask);
96
97 if (!error)
98 coda_cache_enter(inode, mask);
99
100 return error;
101}
102
103
104static inline void coda_dir_update_mtime(struct inode *dir)
105{
106#ifdef REQUERY_VENUS_FOR_MTIME
107 /* invalidate the directory cnode's attributes so we refetch the
108 * attributes from venus next time the inode is referenced */
109 coda_flag_inode(dir, C_VATTR);
110#else
111 /* optimistically we can also act as if our nose bleeds. The
112 * granularity of the mtime is coarse anyways so we might actually be
113 * right most of the time. Note: we only do this for directories. */
114 dir->i_mtime = dir->i_ctime = current_time(dir);
115#endif
116}
117
118/* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
119 * trick to fool GNU find's optimizations. If we can't be sure of the link
120 * (because of volume mount points) we set i_nlink to 1 which forces find
121 * to consider every child as a possible directory. We should also never
122 * see an increment or decrement for deleted directories where i_nlink == 0 */
123static inline void coda_dir_inc_nlink(struct inode *dir)
124{
125 if (dir->i_nlink >= 2)
126 inc_nlink(dir);
127}
128
129static inline void coda_dir_drop_nlink(struct inode *dir)
130{
131 if (dir->i_nlink > 2)
132 drop_nlink(dir);
133}
134
135/* creation routines: create, mknod, mkdir, link, symlink */
136static int coda_create(struct user_namespace *mnt_userns, struct inode *dir,
137 struct dentry *de, umode_t mode, bool excl)
138{
139 int error;
140 const char *name=de->d_name.name;
141 int length=de->d_name.len;
142 struct inode *inode;
143 struct CodaFid newfid;
144 struct coda_vattr attrs;
145
146 if (is_root_inode(dir) && coda_iscontrol(name, length))
147 return -EPERM;
148
149 error = venus_create(dir->i_sb, coda_i2f(dir), name, length,
150 0, mode, &newfid, &attrs);
151 if (error)
152 goto err_out;
153
154 inode = coda_iget(dir->i_sb, &newfid, &attrs);
155 if (IS_ERR(inode)) {
156 error = PTR_ERR(inode);
157 goto err_out;
158 }
159
160 /* invalidate the directory cnode's attributes */
161 coda_dir_update_mtime(dir);
162 d_instantiate(de, inode);
163 return 0;
164err_out:
165 d_drop(de);
166 return error;
167}
168
169static int coda_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
170 struct dentry *de, umode_t mode)
171{
172 struct inode *inode;
173 struct coda_vattr attrs;
174 const char *name = de->d_name.name;
175 int len = de->d_name.len;
176 int error;
177 struct CodaFid newfid;
178
179 if (is_root_inode(dir) && coda_iscontrol(name, len))
180 return -EPERM;
181
182 attrs.va_mode = mode;
183 error = venus_mkdir(dir->i_sb, coda_i2f(dir),
184 name, len, &newfid, &attrs);
185 if (error)
186 goto err_out;
187
188 inode = coda_iget(dir->i_sb, &newfid, &attrs);
189 if (IS_ERR(inode)) {
190 error = PTR_ERR(inode);
191 goto err_out;
192 }
193
194 /* invalidate the directory cnode's attributes */
195 coda_dir_inc_nlink(dir);
196 coda_dir_update_mtime(dir);
197 d_instantiate(de, inode);
198 return 0;
199err_out:
200 d_drop(de);
201 return error;
202}
203
204/* try to make de an entry in dir_inodde linked to source_de */
205static int coda_link(struct dentry *source_de, struct inode *dir_inode,
206 struct dentry *de)
207{
208 struct inode *inode = d_inode(source_de);
209 const char * name = de->d_name.name;
210 int len = de->d_name.len;
211 int error;
212
213 if (is_root_inode(dir_inode) && coda_iscontrol(name, len))
214 return -EPERM;
215
216 error = venus_link(dir_inode->i_sb, coda_i2f(inode),
217 coda_i2f(dir_inode), (const char *)name, len);
218 if (error) {
219 d_drop(de);
220 return error;
221 }
222
223 coda_dir_update_mtime(dir_inode);
224 ihold(inode);
225 d_instantiate(de, inode);
226 inc_nlink(inode);
227 return 0;
228}
229
230
231static int coda_symlink(struct user_namespace *mnt_userns,
232 struct inode *dir_inode, struct dentry *de,
233 const char *symname)
234{
235 const char *name = de->d_name.name;
236 int len = de->d_name.len;
237 int symlen;
238 int error;
239
240 if (is_root_inode(dir_inode) && coda_iscontrol(name, len))
241 return -EPERM;
242
243 symlen = strlen(symname);
244 if (symlen > CODA_MAXPATHLEN)
245 return -ENAMETOOLONG;
246
247 /*
248 * This entry is now negative. Since we do not create
249 * an inode for the entry we have to drop it.
250 */
251 d_drop(de);
252 error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
253 symname, symlen);
254
255 /* mtime is no good anymore */
256 if (!error)
257 coda_dir_update_mtime(dir_inode);
258
259 return error;
260}
261
262/* destruction routines: unlink, rmdir */
263static int coda_unlink(struct inode *dir, struct dentry *de)
264{
265 int error;
266 const char *name = de->d_name.name;
267 int len = de->d_name.len;
268
269 error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
270 if (error)
271 return error;
272
273 coda_dir_update_mtime(dir);
274 drop_nlink(d_inode(de));
275 return 0;
276}
277
278static int coda_rmdir(struct inode *dir, struct dentry *de)
279{
280 const char *name = de->d_name.name;
281 int len = de->d_name.len;
282 int error;
283
284 error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
285 if (!error) {
286 /* VFS may delete the child */
287 if (d_really_is_positive(de))
288 clear_nlink(d_inode(de));
289
290 /* fix the link count of the parent */
291 coda_dir_drop_nlink(dir);
292 coda_dir_update_mtime(dir);
293 }
294 return error;
295}
296
297/* rename */
298static int coda_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
299 struct dentry *old_dentry, struct inode *new_dir,
300 struct dentry *new_dentry, unsigned int flags)
301{
302 const char *old_name = old_dentry->d_name.name;
303 const char *new_name = new_dentry->d_name.name;
304 int old_length = old_dentry->d_name.len;
305 int new_length = new_dentry->d_name.len;
306 int error;
307
308 if (flags)
309 return -EINVAL;
310
311 error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
312 coda_i2f(new_dir), old_length, new_length,
313 (const char *) old_name, (const char *)new_name);
314 if (!error) {
315 if (d_really_is_positive(new_dentry)) {
316 if (d_is_dir(new_dentry)) {
317 coda_dir_drop_nlink(old_dir);
318 coda_dir_inc_nlink(new_dir);
319 }
320 coda_flag_inode(d_inode(new_dentry), C_VATTR);
321 }
322 coda_dir_update_mtime(old_dir);
323 coda_dir_update_mtime(new_dir);
324 }
325 return error;
326}
327
328static inline unsigned int CDT2DT(unsigned char cdt)
329{
330 unsigned int dt;
331
332 switch(cdt) {
333 case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
334 case CDT_FIFO: dt = DT_FIFO; break;
335 case CDT_CHR: dt = DT_CHR; break;
336 case CDT_DIR: dt = DT_DIR; break;
337 case CDT_BLK: dt = DT_BLK; break;
338 case CDT_REG: dt = DT_REG; break;
339 case CDT_LNK: dt = DT_LNK; break;
340 case CDT_SOCK: dt = DT_SOCK; break;
341 case CDT_WHT: dt = DT_WHT; break;
342 default: dt = DT_UNKNOWN; break;
343 }
344 return dt;
345}
346
347/* support routines */
348static int coda_venus_readdir(struct file *coda_file, struct dir_context *ctx)
349{
350 struct coda_file_info *cfi;
351 struct coda_inode_info *cii;
352 struct file *host_file;
353 struct venus_dirent *vdir;
354 unsigned long vdir_size = offsetof(struct venus_dirent, d_name);
355 unsigned int type;
356 struct qstr name;
357 ino_t ino;
358 int ret;
359
360 cfi = coda_ftoc(coda_file);
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 }
417out:
418 kfree(vdir);
419 return 0;
420}
421
422/* file operations for directories */
423static 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 host_file = cfi->cfi_container;
431
432 if (host_file->f_op->iterate || host_file->f_op->iterate_shared) {
433 struct inode *host_inode = file_inode(host_file);
434 ret = -ENOENT;
435 if (!IS_DEADDIR(host_inode)) {
436 if (host_file->f_op->iterate_shared) {
437 inode_lock_shared(host_inode);
438 ret = host_file->f_op->iterate_shared(host_file, ctx);
439 file_accessed(host_file);
440 inode_unlock_shared(host_inode);
441 } else {
442 inode_lock(host_inode);
443 ret = host_file->f_op->iterate(host_file, ctx);
444 file_accessed(host_file);
445 inode_unlock(host_inode);
446 }
447 }
448 return ret;
449 }
450 /* Venus: we must read Venus dirents from a file */
451 return coda_venus_readdir(coda_file, ctx);
452}
453
454/* called when a cache lookup succeeds */
455static int coda_dentry_revalidate(struct dentry *de, unsigned int flags)
456{
457 struct inode *inode;
458 struct coda_inode_info *cii;
459
460 if (flags & LOOKUP_RCU)
461 return -ECHILD;
462
463 inode = d_inode(de);
464 if (!inode || is_root_inode(inode))
465 goto out;
466 if (is_bad_inode(inode))
467 goto bad;
468
469 cii = ITOC(d_inode(de));
470 if (!(cii->c_flags & (C_PURGE | C_FLUSH)))
471 goto out;
472
473 shrink_dcache_parent(de);
474
475 /* propagate for a flush */
476 if (cii->c_flags & C_FLUSH)
477 coda_flag_inode_children(inode, C_FLUSH);
478
479 if (d_count(de) > 1)
480 /* pretend it's valid, but don't change the flags */
481 goto out;
482
483 /* clear the flags. */
484 spin_lock(&cii->c_lock);
485 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
486 spin_unlock(&cii->c_lock);
487bad:
488 return 0;
489out:
490 return 1;
491}
492
493/*
494 * This is the callback from dput() when d_count is going to 0.
495 * We use this to unhash dentries with bad inodes.
496 */
497static int coda_dentry_delete(const struct dentry * dentry)
498{
499 struct inode *inode;
500 struct coda_inode_info *cii;
501
502 if (d_really_is_negative(dentry))
503 return 0;
504
505 inode = d_inode(dentry);
506 if (!inode || is_bad_inode(inode))
507 return 1;
508
509 cii = ITOC(inode);
510 if (cii->c_flags & C_PURGE)
511 return 1;
512
513 return 0;
514}
515
516
517
518/*
519 * This is called when we want to check if the inode has
520 * changed on the server. Coda makes this easy since the
521 * cache manager Venus issues a downcall to the kernel when this
522 * happens
523 */
524int coda_revalidate_inode(struct inode *inode)
525{
526 struct coda_vattr attr;
527 int error;
528 int old_mode;
529 ino_t old_ino;
530 struct coda_inode_info *cii = ITOC(inode);
531
532 if (!cii->c_flags)
533 return 0;
534
535 if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) {
536 error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
537 if (error)
538 return -EIO;
539
540 /* this inode may be lost if:
541 - it's ino changed
542 - type changes must be permitted for repair and
543 missing mount points.
544 */
545 old_mode = inode->i_mode;
546 old_ino = inode->i_ino;
547 coda_vattr_to_iattr(inode, &attr);
548
549 if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
550 pr_warn("inode %ld, fid %s changed type!\n",
551 inode->i_ino, coda_f2s(&(cii->c_fid)));
552 }
553
554 /* the following can happen when a local fid is replaced
555 with a global one, here we lose and declare the inode bad */
556 if (inode->i_ino != old_ino)
557 return -EIO;
558
559 coda_flag_inode_children(inode, C_FLUSH);
560
561 spin_lock(&cii->c_lock);
562 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
563 spin_unlock(&cii->c_lock);
564 }
565 return 0;
566}
567
568const struct dentry_operations coda_dentry_operations = {
569 .d_revalidate = coda_dentry_revalidate,
570 .d_delete = coda_dentry_delete,
571};
572
573const struct inode_operations coda_dir_inode_operations = {
574 .create = coda_create,
575 .lookup = coda_lookup,
576 .link = coda_link,
577 .unlink = coda_unlink,
578 .symlink = coda_symlink,
579 .mkdir = coda_mkdir,
580 .rmdir = coda_rmdir,
581 .mknod = CODA_EIO_ERROR,
582 .rename = coda_rename,
583 .permission = coda_permission,
584 .getattr = coda_getattr,
585 .setattr = coda_setattr,
586};
587
588const struct file_operations coda_dir_operations = {
589 .llseek = generic_file_llseek,
590 .read = generic_read_dir,
591 .iterate = coda_readdir,
592 .open = coda_open,
593 .release = coda_release,
594 .fsync = coda_fsync,
595};