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_psdev.h>
27 #include "coda_linux.h"
28 #include "coda_cache.h"
33 static int coda_create(struct inode
*dir
, struct dentry
*new, int mode
, struct nameidata
*nd
);
34 static struct dentry
*coda_lookup(struct inode
*dir
, struct dentry
*target
, struct nameidata
*nd
);
35 static int coda_link(struct dentry
*old_dentry
, struct inode
*dir_inode
,
36 struct dentry
*entry
);
37 static int coda_unlink(struct inode
*dir_inode
, struct dentry
*entry
);
38 static int coda_symlink(struct inode
*dir_inode
, struct dentry
*entry
,
40 static int coda_mkdir(struct inode
*dir_inode
, struct dentry
*entry
, int mode
);
41 static int coda_rmdir(struct inode
*dir_inode
, struct dentry
*entry
);
42 static int coda_rename(struct inode
*old_inode
, struct dentry
*old_dentry
,
43 struct inode
*new_inode
, struct dentry
*new_dentry
);
46 static int coda_readdir(struct file
*file
, void *buf
, filldir_t filldir
);
49 static int coda_dentry_revalidate(struct dentry
*de
, struct nameidata
*nd
);
50 static int coda_dentry_delete(const struct dentry
*);
52 /* support routines */
53 static int coda_venus_readdir(struct file
*coda_file
, void *buf
,
56 /* same as fs/bad_inode.c */
57 static int coda_return_EIO(void)
61 #define CODA_EIO_ERROR ((void *) (coda_return_EIO))
63 const struct dentry_operations coda_dentry_operations
=
65 .d_revalidate
= coda_dentry_revalidate
,
66 .d_delete
= coda_dentry_delete
,
69 const struct inode_operations coda_dir_inode_operations
=
71 .create
= coda_create
,
72 .lookup
= coda_lookup
,
74 .unlink
= coda_unlink
,
75 .symlink
= coda_symlink
,
78 .mknod
= CODA_EIO_ERROR
,
79 .rename
= coda_rename
,
80 .permission
= coda_permission
,
81 .getattr
= coda_getattr
,
82 .setattr
= coda_setattr
,
85 const struct file_operations coda_dir_operations
= {
86 .llseek
= generic_file_llseek
,
87 .read
= generic_read_dir
,
88 .readdir
= coda_readdir
,
90 .release
= coda_release
,
95 /* inode operations for directories */
96 /* access routines: lookup, readlink, permission */
97 static struct dentry
*coda_lookup(struct inode
*dir
, struct dentry
*entry
, struct nameidata
*nd
)
99 struct inode
*inode
= NULL
;
100 struct CodaFid resfid
= { { 0, } };
103 const char *name
= entry
->d_name
.name
;
104 size_t length
= entry
->d_name
.len
;
106 if (length
> CODA_MAXNAMLEN
) {
107 printk(KERN_ERR
"name too long: lookup, %s (%*s)\n",
108 coda_i2s(dir
), (int)length
, name
);
109 return ERR_PTR(-ENAMETOOLONG
);
112 /* control object, create inode on the fly */
113 if (coda_isroot(dir
) && coda_iscontrol(name
, length
)) {
114 error
= coda_cnode_makectl(&inode
, dir
->i_sb
);
119 error
= venus_lookup(dir
->i_sb
, coda_i2f(dir
), name
, length
,
122 error
= coda_cnode_make(&inode
, &resfid
, dir
->i_sb
);
124 if (error
&& error
!= -ENOENT
)
125 return ERR_PTR(error
);
128 if (inode
&& (type
& CODA_NOCACHE
))
129 coda_flag_inode(inode
, C_VATTR
| C_PURGE
);
131 return d_splice_alias(inode
, entry
);
135 int coda_permission(struct inode
*inode
, int mask
, unsigned int flags
)
139 if (flags
& IPERM_FLAG_RCU
)
142 mask
&= MAY_READ
| MAY_WRITE
| MAY_EXEC
;
147 if ((mask
& MAY_EXEC
) && !execute_ok(inode
))
150 if (coda_cache_check(inode
, mask
))
153 error
= venus_access(inode
->i_sb
, coda_i2f(inode
), mask
);
156 coda_cache_enter(inode
, mask
);
162 static inline void coda_dir_update_mtime(struct inode
*dir
)
164 #ifdef REQUERY_VENUS_FOR_MTIME
165 /* invalidate the directory cnode's attributes so we refetch the
166 * attributes from venus next time the inode is referenced */
167 coda_flag_inode(dir
, C_VATTR
);
169 /* optimistically we can also act as if our nose bleeds. The
170 * granularity of the mtime is coarse anyways so we might actually be
171 * right most of the time. Note: we only do this for directories. */
172 dir
->i_mtime
= dir
->i_ctime
= CURRENT_TIME_SEC
;
176 /* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
177 * trick to fool GNU find's optimizations. If we can't be sure of the link
178 * (because of volume mount points) we set i_nlink to 1 which forces find
179 * to consider every child as a possible directory. We should also never
180 * see an increment or decrement for deleted directories where i_nlink == 0 */
181 static inline void coda_dir_inc_nlink(struct inode
*dir
)
183 if (dir
->i_nlink
>= 2)
187 static inline void coda_dir_drop_nlink(struct inode
*dir
)
189 if (dir
->i_nlink
> 2)
193 /* creation routines: create, mknod, mkdir, link, symlink */
194 static int coda_create(struct inode
*dir
, struct dentry
*de
, int mode
, struct nameidata
*nd
)
197 const char *name
=de
->d_name
.name
;
198 int length
=de
->d_name
.len
;
200 struct CodaFid newfid
;
201 struct coda_vattr attrs
;
203 if (coda_isroot(dir
) && coda_iscontrol(name
, length
))
206 error
= venus_create(dir
->i_sb
, coda_i2f(dir
), name
, length
,
207 0, mode
, &newfid
, &attrs
);
211 inode
= coda_iget(dir
->i_sb
, &newfid
, &attrs
);
213 error
= PTR_ERR(inode
);
217 /* invalidate the directory cnode's attributes */
218 coda_dir_update_mtime(dir
);
219 d_instantiate(de
, inode
);
226 static int coda_mkdir(struct inode
*dir
, struct dentry
*de
, int mode
)
229 struct coda_vattr attrs
;
230 const char *name
= de
->d_name
.name
;
231 int len
= de
->d_name
.len
;
233 struct CodaFid newfid
;
235 if (coda_isroot(dir
) && coda_iscontrol(name
, len
))
238 attrs
.va_mode
= mode
;
239 error
= venus_mkdir(dir
->i_sb
, coda_i2f(dir
),
240 name
, len
, &newfid
, &attrs
);
244 inode
= coda_iget(dir
->i_sb
, &newfid
, &attrs
);
246 error
= PTR_ERR(inode
);
250 /* invalidate the directory cnode's attributes */
251 coda_dir_inc_nlink(dir
);
252 coda_dir_update_mtime(dir
);
253 d_instantiate(de
, inode
);
260 /* try to make de an entry in dir_inodde linked to source_de */
261 static int coda_link(struct dentry
*source_de
, struct inode
*dir_inode
,
264 struct inode
*inode
= source_de
->d_inode
;
265 const char * name
= de
->d_name
.name
;
266 int len
= de
->d_name
.len
;
269 if (coda_isroot(dir_inode
) && coda_iscontrol(name
, len
))
272 error
= venus_link(dir_inode
->i_sb
, coda_i2f(inode
),
273 coda_i2f(dir_inode
), (const char *)name
, len
);
279 coda_dir_update_mtime(dir_inode
);
281 d_instantiate(de
, inode
);
287 static int coda_symlink(struct inode
*dir_inode
, struct dentry
*de
,
290 const char *name
= de
->d_name
.name
;
291 int len
= de
->d_name
.len
;
295 if (coda_isroot(dir_inode
) && coda_iscontrol(name
, len
))
298 symlen
= strlen(symname
);
299 if (symlen
> CODA_MAXPATHLEN
)
300 return -ENAMETOOLONG
;
303 * This entry is now negative. Since we do not create
304 * an inode for the entry we have to drop it.
307 error
= venus_symlink(dir_inode
->i_sb
, coda_i2f(dir_inode
), name
, len
,
310 /* mtime is no good anymore */
312 coda_dir_update_mtime(dir_inode
);
317 /* destruction routines: unlink, rmdir */
318 static int coda_unlink(struct inode
*dir
, struct dentry
*de
)
321 const char *name
= de
->d_name
.name
;
322 int len
= de
->d_name
.len
;
324 error
= venus_remove(dir
->i_sb
, coda_i2f(dir
), name
, len
);
328 coda_dir_update_mtime(dir
);
329 drop_nlink(de
->d_inode
);
333 static int coda_rmdir(struct inode
*dir
, struct dentry
*de
)
335 const char *name
= de
->d_name
.name
;
336 int len
= de
->d_name
.len
;
341 error
= venus_rmdir(dir
->i_sb
, coda_i2f(dir
), name
, len
);
343 /* VFS may delete the child */
345 de
->d_inode
->i_nlink
= 0;
347 /* fix the link count of the parent */
348 coda_dir_drop_nlink(dir
);
349 coda_dir_update_mtime(dir
);
355 static int coda_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
356 struct inode
*new_dir
, struct dentry
*new_dentry
)
358 const char *old_name
= old_dentry
->d_name
.name
;
359 const char *new_name
= new_dentry
->d_name
.name
;
360 int old_length
= old_dentry
->d_name
.len
;
361 int new_length
= new_dentry
->d_name
.len
;
364 if (new_dentry
->d_inode
&& S_ISDIR(new_dentry
->d_inode
->i_mode
))
365 dentry_unhash(new_dentry
);
367 error
= venus_rename(old_dir
->i_sb
, coda_i2f(old_dir
),
368 coda_i2f(new_dir
), old_length
, new_length
,
369 (const char *) old_name
, (const char *)new_name
);
371 if (new_dentry
->d_inode
) {
372 if (S_ISDIR(new_dentry
->d_inode
->i_mode
)) {
373 coda_dir_drop_nlink(old_dir
);
374 coda_dir_inc_nlink(new_dir
);
376 coda_dir_update_mtime(old_dir
);
377 coda_dir_update_mtime(new_dir
);
378 coda_flag_inode(new_dentry
->d_inode
, C_VATTR
);
380 coda_flag_inode(old_dir
, C_VATTR
);
381 coda_flag_inode(new_dir
, C_VATTR
);
388 /* file operations for directories */
389 static int coda_readdir(struct file
*coda_file
, void *buf
, filldir_t filldir
)
391 struct coda_file_info
*cfi
;
392 struct file
*host_file
;
395 cfi
= CODA_FTOC(coda_file
);
396 BUG_ON(!cfi
|| cfi
->cfi_magic
!= CODA_MAGIC
);
397 host_file
= cfi
->cfi_container
;
399 if (!host_file
->f_op
)
402 if (host_file
->f_op
->readdir
)
404 /* potemkin case: we were handed a directory inode.
405 * We can't use vfs_readdir because we have to keep the file
406 * position in sync between the coda_file and the host_file.
407 * and as such we need grab the inode mutex. */
408 struct inode
*host_inode
= host_file
->f_path
.dentry
->d_inode
;
410 mutex_lock(&host_inode
->i_mutex
);
411 host_file
->f_pos
= coda_file
->f_pos
;
414 if (!IS_DEADDIR(host_inode
)) {
415 ret
= host_file
->f_op
->readdir(host_file
, buf
, filldir
);
416 file_accessed(host_file
);
419 coda_file
->f_pos
= host_file
->f_pos
;
420 mutex_unlock(&host_inode
->i_mutex
);
422 else /* Venus: we must read Venus dirents from a file */
423 ret
= coda_venus_readdir(coda_file
, buf
, filldir
);
428 static inline unsigned int CDT2DT(unsigned char cdt
)
433 case CDT_UNKNOWN
: dt
= DT_UNKNOWN
; break;
434 case CDT_FIFO
: dt
= DT_FIFO
; break;
435 case CDT_CHR
: dt
= DT_CHR
; break;
436 case CDT_DIR
: dt
= DT_DIR
; break;
437 case CDT_BLK
: dt
= DT_BLK
; break;
438 case CDT_REG
: dt
= DT_REG
; break;
439 case CDT_LNK
: dt
= DT_LNK
; break;
440 case CDT_SOCK
: dt
= DT_SOCK
; break;
441 case CDT_WHT
: dt
= DT_WHT
; break;
442 default: dt
= DT_UNKNOWN
; break;
447 /* support routines */
448 static int coda_venus_readdir(struct file
*coda_file
, void *buf
,
451 int result
= 0; /* # of entries returned */
452 struct coda_file_info
*cfi
;
453 struct coda_inode_info
*cii
;
454 struct file
*host_file
;
456 struct venus_dirent
*vdir
;
457 unsigned long vdir_size
=
458 (unsigned long)(&((struct venus_dirent
*)0)->d_name
);
464 cfi
= CODA_FTOC(coda_file
);
465 BUG_ON(!cfi
|| cfi
->cfi_magic
!= CODA_MAGIC
);
466 host_file
= cfi
->cfi_container
;
468 de
= coda_file
->f_path
.dentry
;
469 cii
= ITOC(de
->d_inode
);
471 vdir
= kmalloc(sizeof(*vdir
), GFP_KERNEL
);
472 if (!vdir
) return -ENOMEM
;
474 if (coda_file
->f_pos
== 0) {
475 ret
= filldir(buf
, ".", 1, 0, de
->d_inode
->i_ino
, DT_DIR
);
481 if (coda_file
->f_pos
== 1) {
482 ret
= filldir(buf
, "..", 2, 1, de
->d_parent
->d_inode
->i_ino
, DT_DIR
);
489 /* read entries from the directory file */
490 ret
= kernel_read(host_file
, coda_file
->f_pos
- 2, (char *)vdir
,
493 printk(KERN_ERR
"coda readdir: read dir %s failed %d\n",
494 coda_f2s(&cii
->c_fid
), ret
);
497 if (ret
== 0) break; /* end of directory file reached */
499 /* catch truncated reads */
500 if (ret
< vdir_size
|| ret
< vdir_size
+ vdir
->d_namlen
) {
501 printk(KERN_ERR
"coda readdir: short read on %s\n",
502 coda_f2s(&cii
->c_fid
));
506 /* validate whether the directory file actually makes sense */
507 if (vdir
->d_reclen
< vdir_size
+ vdir
->d_namlen
) {
508 printk(KERN_ERR
"coda readdir: invalid dir %s\n",
509 coda_f2s(&cii
->c_fid
));
514 name
.len
= vdir
->d_namlen
;
515 name
.name
= vdir
->d_name
;
517 /* Make sure we skip '.' and '..', we already got those */
518 if (name
.name
[0] == '.' && (name
.len
== 1 ||
519 (vdir
->d_name
[1] == '.' && name
.len
== 2)))
520 vdir
->d_fileno
= name
.len
= 0;
522 /* skip null entries */
523 if (vdir
->d_fileno
&& name
.len
) {
524 /* try to look up this entry in the dcache, that way
525 * userspace doesn't have to worry about breaking
526 * getcwd by having mismatched inode numbers for
527 * internal volume mountpoints. */
528 ino
= find_inode_number(de
, &name
);
529 if (!ino
) ino
= vdir
->d_fileno
;
531 type
= CDT2DT(vdir
->d_type
);
532 ret
= filldir(buf
, name
.name
, name
.len
,
533 coda_file
->f_pos
, ino
, type
);
534 /* failure means no space for filling in this round */
538 /* we'll always have progress because d_reclen is unsigned and
539 * we've already established it is non-zero. */
540 coda_file
->f_pos
+= vdir
->d_reclen
;
544 return result
? result
: ret
;
547 /* called when a cache lookup succeeds */
548 static int coda_dentry_revalidate(struct dentry
*de
, struct nameidata
*nd
)
551 struct coda_inode_info
*cii
;
553 if (nd
->flags
& LOOKUP_RCU
)
557 if (!inode
|| coda_isroot(inode
))
559 if (is_bad_inode(inode
))
562 cii
= ITOC(de
->d_inode
);
563 if (!(cii
->c_flags
& (C_PURGE
| C_FLUSH
)))
566 shrink_dcache_parent(de
);
568 /* propagate for a flush */
569 if (cii
->c_flags
& C_FLUSH
)
570 coda_flag_inode_children(inode
, C_FLUSH
);
573 /* pretend it's valid, but don't change the flags */
576 /* clear the flags. */
577 spin_lock(&cii
->c_lock
);
578 cii
->c_flags
&= ~(C_VATTR
| C_PURGE
| C_FLUSH
);
579 spin_unlock(&cii
->c_lock
);
587 * This is the callback from dput() when d_count is going to 0.
588 * We use this to unhash dentries with bad inodes.
590 static int coda_dentry_delete(const struct dentry
* dentry
)
594 if (!dentry
->d_inode
)
597 flags
= (ITOC(dentry
->d_inode
)->c_flags
) & C_PURGE
;
598 if (is_bad_inode(dentry
->d_inode
) || flags
) {
607 * This is called when we want to check if the inode has
608 * changed on the server. Coda makes this easy since the
609 * cache manager Venus issues a downcall to the kernel when this
612 int coda_revalidate_inode(struct dentry
*dentry
)
614 struct coda_vattr attr
;
618 struct inode
*inode
= dentry
->d_inode
;
619 struct coda_inode_info
*cii
= ITOC(inode
);
624 if (cii
->c_flags
& (C_VATTR
| C_PURGE
| C_FLUSH
)) {
625 error
= venus_getattr(inode
->i_sb
, &(cii
->c_fid
), &attr
);
629 /* this inode may be lost if:
631 - type changes must be permitted for repair and
632 missing mount points.
634 old_mode
= inode
->i_mode
;
635 old_ino
= inode
->i_ino
;
636 coda_vattr_to_iattr(inode
, &attr
);
638 if ((old_mode
& S_IFMT
) != (inode
->i_mode
& S_IFMT
)) {
639 printk("Coda: inode %ld, fid %s changed type!\n",
640 inode
->i_ino
, coda_f2s(&(cii
->c_fid
)));
643 /* the following can happen when a local fid is replaced
644 with a global one, here we lose and declare the inode bad */
645 if (inode
->i_ino
!= old_ino
)
648 coda_flag_inode_children(inode
, C_FLUSH
);
650 spin_lock(&cii
->c_lock
);
651 cii
->c_flags
&= ~(C_VATTR
| C_PURGE
| C_FLUSH
);
652 spin_unlock(&cii
->c_lock
);