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
7 * Carnegie Mellon encourages users to contribute improvements to
8 * the Coda project. Contact Peter Braam (coda@cs.cmu.edu).
11 #include <linux/types.h>
12 #include <linux/kernel.h>
13 #include <linux/time.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>
23 #include <asm/uaccess.h>
25 #include <linux/coda.h>
26 #include <linux/coda_linux.h>
27 #include <linux/coda_psdev.h>
28 #include <linux/coda_fs_i.h>
29 #include <linux/coda_cache.h>
34 static int coda_create(struct inode
*dir
, struct dentry
*new, int mode
, struct nameidata
*nd
);
35 static struct dentry
*coda_lookup(struct inode
*dir
, struct dentry
*target
, struct nameidata
*nd
);
36 static int coda_link(struct dentry
*old_dentry
, struct inode
*dir_inode
,
37 struct dentry
*entry
);
38 static int coda_unlink(struct inode
*dir_inode
, struct dentry
*entry
);
39 static int coda_symlink(struct inode
*dir_inode
, struct dentry
*entry
,
41 static int coda_mkdir(struct inode
*dir_inode
, struct dentry
*entry
, int mode
);
42 static int coda_rmdir(struct inode
*dir_inode
, struct dentry
*entry
);
43 static int coda_rename(struct inode
*old_inode
, struct dentry
*old_dentry
,
44 struct inode
*new_inode
, struct dentry
*new_dentry
);
47 static int coda_readdir(struct file
*file
, void *buf
, filldir_t filldir
);
50 static int coda_dentry_revalidate(struct dentry
*de
, struct nameidata
*nd
);
51 static int coda_dentry_delete(const struct dentry
*);
53 /* support routines */
54 static int coda_venus_readdir(struct file
*coda_file
, void *buf
,
57 /* same as fs/bad_inode.c */
58 static int coda_return_EIO(void)
62 #define CODA_EIO_ERROR ((void *) (coda_return_EIO))
64 static const struct dentry_operations coda_dentry_operations
=
66 .d_revalidate
= coda_dentry_revalidate
,
67 .d_delete
= coda_dentry_delete
,
70 const struct inode_operations coda_dir_inode_operations
=
72 .create
= coda_create
,
73 .lookup
= coda_lookup
,
75 .unlink
= coda_unlink
,
76 .symlink
= coda_symlink
,
79 .mknod
= CODA_EIO_ERROR
,
80 .rename
= coda_rename
,
81 .permission
= coda_permission
,
82 .getattr
= coda_getattr
,
83 .setattr
= coda_setattr
,
86 const struct file_operations coda_dir_operations
= {
87 .llseek
= generic_file_llseek
,
88 .read
= generic_read_dir
,
89 .readdir
= coda_readdir
,
91 .release
= coda_release
,
96 /* inode operations for directories */
97 /* access routines: lookup, readlink, permission */
98 static struct dentry
*coda_lookup(struct inode
*dir
, struct dentry
*entry
, struct nameidata
*nd
)
100 struct inode
*inode
= NULL
;
101 struct CodaFid resfid
= { { 0, } };
104 const char *name
= entry
->d_name
.name
;
105 size_t length
= entry
->d_name
.len
;
107 if (length
> CODA_MAXNAMLEN
) {
108 printk(KERN_ERR
"name too long: lookup, %s (%*s)\n",
109 coda_i2s(dir
), (int)length
, name
);
110 return ERR_PTR(-ENAMETOOLONG
);
113 /* control object, create inode on the fly */
114 if (coda_isroot(dir
) && coda_iscontrol(name
, length
)) {
115 error
= coda_cnode_makectl(&inode
, dir
->i_sb
);
120 error
= venus_lookup(dir
->i_sb
, coda_i2f(dir
), name
, length
,
123 error
= coda_cnode_make(&inode
, &resfid
, dir
->i_sb
);
125 if (error
&& error
!= -ENOENT
)
126 return ERR_PTR(error
);
129 d_set_d_op(entry
, &coda_dentry_operations
);
131 if (inode
&& (type
& CODA_NOCACHE
))
132 coda_flag_inode(inode
, C_VATTR
| C_PURGE
);
134 return d_splice_alias(inode
, entry
);
138 int coda_permission(struct inode
*inode
, int mask
, unsigned int flags
)
142 if (flags
& IPERM_FLAG_RCU
)
145 mask
&= MAY_READ
| MAY_WRITE
| MAY_EXEC
;
150 if ((mask
& MAY_EXEC
) && !execute_ok(inode
))
153 if (coda_cache_check(inode
, mask
))
156 error
= venus_access(inode
->i_sb
, coda_i2f(inode
), mask
);
159 coda_cache_enter(inode
, mask
);
165 static inline void coda_dir_update_mtime(struct inode
*dir
)
167 #ifdef REQUERY_VENUS_FOR_MTIME
168 /* invalidate the directory cnode's attributes so we refetch the
169 * attributes from venus next time the inode is referenced */
170 coda_flag_inode(dir
, C_VATTR
);
172 /* optimistically we can also act as if our nose bleeds. The
173 * granularity of the mtime is coarse anyways so we might actually be
174 * right most of the time. Note: we only do this for directories. */
175 dir
->i_mtime
= dir
->i_ctime
= CURRENT_TIME_SEC
;
179 /* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
180 * trick to fool GNU find's optimizations. If we can't be sure of the link
181 * (because of volume mount points) we set i_nlink to 1 which forces find
182 * to consider every child as a possible directory. We should also never
183 * see an increment or decrement for deleted directories where i_nlink == 0 */
184 static inline void coda_dir_inc_nlink(struct inode
*dir
)
186 if (dir
->i_nlink
>= 2)
190 static inline void coda_dir_drop_nlink(struct inode
*dir
)
192 if (dir
->i_nlink
> 2)
196 /* creation routines: create, mknod, mkdir, link, symlink */
197 static int coda_create(struct inode
*dir
, struct dentry
*de
, int mode
, struct nameidata
*nd
)
200 const char *name
=de
->d_name
.name
;
201 int length
=de
->d_name
.len
;
203 struct CodaFid newfid
;
204 struct coda_vattr attrs
;
206 if (coda_isroot(dir
) && coda_iscontrol(name
, length
))
209 error
= venus_create(dir
->i_sb
, coda_i2f(dir
), name
, length
,
210 0, mode
, &newfid
, &attrs
);
214 inode
= coda_iget(dir
->i_sb
, &newfid
, &attrs
);
216 error
= PTR_ERR(inode
);
220 /* invalidate the directory cnode's attributes */
221 coda_dir_update_mtime(dir
);
222 d_instantiate(de
, inode
);
229 static int coda_mkdir(struct inode
*dir
, struct dentry
*de
, int mode
)
232 struct coda_vattr attrs
;
233 const char *name
= de
->d_name
.name
;
234 int len
= de
->d_name
.len
;
236 struct CodaFid newfid
;
238 if (coda_isroot(dir
) && coda_iscontrol(name
, len
))
241 attrs
.va_mode
= mode
;
242 error
= venus_mkdir(dir
->i_sb
, coda_i2f(dir
),
243 name
, len
, &newfid
, &attrs
);
247 inode
= coda_iget(dir
->i_sb
, &newfid
, &attrs
);
249 error
= PTR_ERR(inode
);
253 /* invalidate the directory cnode's attributes */
254 coda_dir_inc_nlink(dir
);
255 coda_dir_update_mtime(dir
);
256 d_instantiate(de
, inode
);
263 /* try to make de an entry in dir_inodde linked to source_de */
264 static int coda_link(struct dentry
*source_de
, struct inode
*dir_inode
,
267 struct inode
*inode
= source_de
->d_inode
;
268 const char * name
= de
->d_name
.name
;
269 int len
= de
->d_name
.len
;
272 if (coda_isroot(dir_inode
) && coda_iscontrol(name
, len
))
275 error
= venus_link(dir_inode
->i_sb
, coda_i2f(inode
),
276 coda_i2f(dir_inode
), (const char *)name
, len
);
282 coda_dir_update_mtime(dir_inode
);
284 d_instantiate(de
, inode
);
290 static int coda_symlink(struct inode
*dir_inode
, struct dentry
*de
,
293 const char *name
= de
->d_name
.name
;
294 int len
= de
->d_name
.len
;
298 if (coda_isroot(dir_inode
) && coda_iscontrol(name
, len
))
301 symlen
= strlen(symname
);
302 if (symlen
> CODA_MAXPATHLEN
)
303 return -ENAMETOOLONG
;
306 * This entry is now negative. Since we do not create
307 * an inode for the entry we have to drop it.
310 error
= venus_symlink(dir_inode
->i_sb
, coda_i2f(dir_inode
), name
, len
,
313 /* mtime is no good anymore */
315 coda_dir_update_mtime(dir_inode
);
320 /* destruction routines: unlink, rmdir */
321 static int coda_unlink(struct inode
*dir
, struct dentry
*de
)
324 const char *name
= de
->d_name
.name
;
325 int len
= de
->d_name
.len
;
327 error
= venus_remove(dir
->i_sb
, coda_i2f(dir
), name
, len
);
331 coda_dir_update_mtime(dir
);
332 drop_nlink(de
->d_inode
);
336 static int coda_rmdir(struct inode
*dir
, struct dentry
*de
)
338 const char *name
= de
->d_name
.name
;
339 int len
= de
->d_name
.len
;
342 error
= venus_rmdir(dir
->i_sb
, coda_i2f(dir
), name
, len
);
344 /* VFS may delete the child */
346 de
->d_inode
->i_nlink
= 0;
348 /* fix the link count of the parent */
349 coda_dir_drop_nlink(dir
);
350 coda_dir_update_mtime(dir
);
356 static int coda_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
357 struct inode
*new_dir
, struct dentry
*new_dentry
)
359 const char *old_name
= old_dentry
->d_name
.name
;
360 const char *new_name
= new_dentry
->d_name
.name
;
361 int old_length
= old_dentry
->d_name
.len
;
362 int new_length
= new_dentry
->d_name
.len
;
365 error
= venus_rename(old_dir
->i_sb
, coda_i2f(old_dir
),
366 coda_i2f(new_dir
), old_length
, new_length
,
367 (const char *) old_name
, (const char *)new_name
);
369 if (new_dentry
->d_inode
) {
370 if (S_ISDIR(new_dentry
->d_inode
->i_mode
)) {
371 coda_dir_drop_nlink(old_dir
);
372 coda_dir_inc_nlink(new_dir
);
374 coda_dir_update_mtime(old_dir
);
375 coda_dir_update_mtime(new_dir
);
376 coda_flag_inode(new_dentry
->d_inode
, C_VATTR
);
378 coda_flag_inode(old_dir
, C_VATTR
);
379 coda_flag_inode(new_dir
, C_VATTR
);
386 /* file operations for directories */
387 static int coda_readdir(struct file
*coda_file
, void *buf
, filldir_t filldir
)
389 struct coda_file_info
*cfi
;
390 struct file
*host_file
;
393 cfi
= CODA_FTOC(coda_file
);
394 BUG_ON(!cfi
|| cfi
->cfi_magic
!= CODA_MAGIC
);
395 host_file
= cfi
->cfi_container
;
397 if (!host_file
->f_op
)
400 if (host_file
->f_op
->readdir
)
402 /* potemkin case: we were handed a directory inode.
403 * We can't use vfs_readdir because we have to keep the file
404 * position in sync between the coda_file and the host_file.
405 * and as such we need grab the inode mutex. */
406 struct inode
*host_inode
= host_file
->f_path
.dentry
->d_inode
;
408 mutex_lock(&host_inode
->i_mutex
);
409 host_file
->f_pos
= coda_file
->f_pos
;
412 if (!IS_DEADDIR(host_inode
)) {
413 ret
= host_file
->f_op
->readdir(host_file
, buf
, filldir
);
414 file_accessed(host_file
);
417 coda_file
->f_pos
= host_file
->f_pos
;
418 mutex_unlock(&host_inode
->i_mutex
);
420 else /* Venus: we must read Venus dirents from a file */
421 ret
= coda_venus_readdir(coda_file
, buf
, filldir
);
426 static inline unsigned int CDT2DT(unsigned char cdt
)
431 case CDT_UNKNOWN
: dt
= DT_UNKNOWN
; break;
432 case CDT_FIFO
: dt
= DT_FIFO
; break;
433 case CDT_CHR
: dt
= DT_CHR
; break;
434 case CDT_DIR
: dt
= DT_DIR
; break;
435 case CDT_BLK
: dt
= DT_BLK
; break;
436 case CDT_REG
: dt
= DT_REG
; break;
437 case CDT_LNK
: dt
= DT_LNK
; break;
438 case CDT_SOCK
: dt
= DT_SOCK
; break;
439 case CDT_WHT
: dt
= DT_WHT
; break;
440 default: dt
= DT_UNKNOWN
; break;
445 /* support routines */
446 static int coda_venus_readdir(struct file
*coda_file
, void *buf
,
449 int result
= 0; /* # of entries returned */
450 struct coda_file_info
*cfi
;
451 struct coda_inode_info
*cii
;
452 struct file
*host_file
;
454 struct venus_dirent
*vdir
;
455 unsigned long vdir_size
=
456 (unsigned long)(&((struct venus_dirent
*)0)->d_name
);
462 cfi
= CODA_FTOC(coda_file
);
463 BUG_ON(!cfi
|| cfi
->cfi_magic
!= CODA_MAGIC
);
464 host_file
= cfi
->cfi_container
;
466 de
= coda_file
->f_path
.dentry
;
467 cii
= ITOC(de
->d_inode
);
469 vdir
= kmalloc(sizeof(*vdir
), GFP_KERNEL
);
470 if (!vdir
) return -ENOMEM
;
472 if (coda_file
->f_pos
== 0) {
473 ret
= filldir(buf
, ".", 1, 0, de
->d_inode
->i_ino
, DT_DIR
);
479 if (coda_file
->f_pos
== 1) {
480 ret
= filldir(buf
, "..", 2, 1, de
->d_parent
->d_inode
->i_ino
, DT_DIR
);
487 /* read entries from the directory file */
488 ret
= kernel_read(host_file
, coda_file
->f_pos
- 2, (char *)vdir
,
491 printk(KERN_ERR
"coda readdir: read dir %s failed %d\n",
492 coda_f2s(&cii
->c_fid
), ret
);
495 if (ret
== 0) break; /* end of directory file reached */
497 /* catch truncated reads */
498 if (ret
< vdir_size
|| ret
< vdir_size
+ vdir
->d_namlen
) {
499 printk(KERN_ERR
"coda readdir: short read on %s\n",
500 coda_f2s(&cii
->c_fid
));
504 /* validate whether the directory file actually makes sense */
505 if (vdir
->d_reclen
< vdir_size
+ vdir
->d_namlen
) {
506 printk(KERN_ERR
"coda readdir: invalid dir %s\n",
507 coda_f2s(&cii
->c_fid
));
512 name
.len
= vdir
->d_namlen
;
513 name
.name
= vdir
->d_name
;
515 /* Make sure we skip '.' and '..', we already got those */
516 if (name
.name
[0] == '.' && (name
.len
== 1 ||
517 (vdir
->d_name
[1] == '.' && name
.len
== 2)))
518 vdir
->d_fileno
= name
.len
= 0;
520 /* skip null entries */
521 if (vdir
->d_fileno
&& name
.len
) {
522 /* try to look up this entry in the dcache, that way
523 * userspace doesn't have to worry about breaking
524 * getcwd by having mismatched inode numbers for
525 * internal volume mountpoints. */
526 ino
= find_inode_number(de
, &name
);
527 if (!ino
) ino
= vdir
->d_fileno
;
529 type
= CDT2DT(vdir
->d_type
);
530 ret
= filldir(buf
, name
.name
, name
.len
,
531 coda_file
->f_pos
, ino
, type
);
532 /* failure means no space for filling in this round */
536 /* we'll always have progress because d_reclen is unsigned and
537 * we've already established it is non-zero. */
538 coda_file
->f_pos
+= vdir
->d_reclen
;
542 return result
? result
: ret
;
545 /* called when a cache lookup succeeds */
546 static int coda_dentry_revalidate(struct dentry
*de
, struct nameidata
*nd
)
549 struct coda_inode_info
*cii
;
551 if (nd
->flags
& LOOKUP_RCU
)
555 if (!inode
|| coda_isroot(inode
))
557 if (is_bad_inode(inode
))
560 cii
= ITOC(de
->d_inode
);
561 if (!(cii
->c_flags
& (C_PURGE
| C_FLUSH
)))
564 shrink_dcache_parent(de
);
566 /* propagate for a flush */
567 if (cii
->c_flags
& C_FLUSH
)
568 coda_flag_inode_children(inode
, C_FLUSH
);
571 /* pretend it's valid, but don't change the flags */
574 /* clear the flags. */
575 spin_lock(&cii
->c_lock
);
576 cii
->c_flags
&= ~(C_VATTR
| C_PURGE
| C_FLUSH
);
577 spin_unlock(&cii
->c_lock
);
585 * This is the callback from dput() when d_count is going to 0.
586 * We use this to unhash dentries with bad inodes.
588 static int coda_dentry_delete(const struct dentry
* dentry
)
592 if (!dentry
->d_inode
)
595 flags
= (ITOC(dentry
->d_inode
)->c_flags
) & C_PURGE
;
596 if (is_bad_inode(dentry
->d_inode
) || flags
) {
605 * This is called when we want to check if the inode has
606 * changed on the server. Coda makes this easy since the
607 * cache manager Venus issues a downcall to the kernel when this
610 int coda_revalidate_inode(struct dentry
*dentry
)
612 struct coda_vattr attr
;
616 struct inode
*inode
= dentry
->d_inode
;
617 struct coda_inode_info
*cii
= ITOC(inode
);
622 if (cii
->c_flags
& (C_VATTR
| C_PURGE
| C_FLUSH
)) {
623 error
= venus_getattr(inode
->i_sb
, &(cii
->c_fid
), &attr
);
627 /* this inode may be lost if:
629 - type changes must be permitted for repair and
630 missing mount points.
632 old_mode
= inode
->i_mode
;
633 old_ino
= inode
->i_ino
;
634 coda_vattr_to_iattr(inode
, &attr
);
636 if ((old_mode
& S_IFMT
) != (inode
->i_mode
& S_IFMT
)) {
637 printk("Coda: inode %ld, fid %s changed type!\n",
638 inode
->i_ino
, coda_f2s(&(cii
->c_fid
)));
641 /* the following can happen when a local fid is replaced
642 with a global one, here we lose and declare the inode bad */
643 if (inode
->i_ino
!= old_ino
)
646 coda_flag_inode_children(inode
, C_FLUSH
);
648 spin_lock(&cii
->c_lock
);
649 cii
->c_flags
&= ~(C_VATTR
| C_PURGE
| C_FLUSH
);
650 spin_unlock(&cii
->c_lock
);