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/file.h>
16 #include <linux/stat.h>
17 #include <linux/errno.h>
18 #include <linux/string.h>
19 #include <linux/smp_lock.h>
21 #include <asm/uaccess.h>
23 #include <linux/coda.h>
24 #include <linux/coda_linux.h>
25 #include <linux/coda_psdev.h>
26 #include <linux/coda_fs_i.h>
27 #include <linux/coda_cache.h>
28 #include <linux/coda_proc.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 *dirent
, filldir_t filldir
);
49 static int coda_dentry_revalidate(struct dentry
*de
, struct nameidata
*nd
);
50 static int coda_dentry_delete(struct dentry
*);
52 /* support routines */
53 static int coda_venus_readdir(struct file
*filp
, filldir_t filldir
,
54 void *dirent
, struct dentry
*dir
);
56 /* same as fs/bad_inode.c */
57 static int coda_return_EIO(void)
61 #define CODA_EIO_ERROR ((void *) (coda_return_EIO))
63 static 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
,
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
*res_inode
= NULL
;
101 struct CodaFid resfid
= { { 0, } };
102 int dropme
= 0; /* to indicate entry should not be cached */
105 const char *name
= entry
->d_name
.name
;
106 size_t length
= entry
->d_name
.len
;
108 if ( length
> CODA_MAXNAMLEN
) {
109 printk("name too long: lookup, %s (%*s)\n",
110 coda_i2s(dir
), (int)length
, name
);
111 return ERR_PTR(-ENAMETOOLONG
);
115 /* control object, create inode on the fly */
116 if (coda_isroot(dir
) && coda_iscontrol(name
, length
)) {
117 error
= coda_cnode_makectl(&res_inode
, dir
->i_sb
);
122 error
= venus_lookup(dir
->i_sb
, coda_i2f(dir
),
123 (const char *)name
, length
, &type
, &resfid
);
127 if (type
& CODA_NOCACHE
) {
128 type
&= (~CODA_NOCACHE
);
132 error
= coda_cnode_make(&res_inode
, &resfid
, dir
->i_sb
);
135 return ERR_PTR(error
);
137 } else if (error
!= -ENOENT
) {
139 return ERR_PTR(error
);
144 entry
->d_op
= &coda_dentry_operations
;
145 d_add(entry
, res_inode
);
148 coda_flag_inode(res_inode
, C_VATTR
);
155 int coda_permission(struct inode
*inode
, int mask
, struct nameidata
*nd
)
164 coda_vfs_stat
.permission
++;
166 if (coda_cache_check(inode
, mask
))
169 error
= venus_access(inode
->i_sb
, coda_i2f(inode
), mask
);
172 coda_cache_enter(inode
, mask
);
180 static inline void coda_dir_update_mtime(struct inode
*dir
)
182 #ifdef REQUERY_VENUS_FOR_MTIME
183 /* invalidate the directory cnode's attributes so we refetch the
184 * attributes from venus next time the inode is referenced */
185 coda_flag_inode(dir
, C_VATTR
);
187 /* optimistically we can also act as if our nose bleeds. The
188 * granularity of the mtime is coarse anyways so we might actually be
189 * right most of the time. Note: we only do this for directories. */
190 dir
->i_mtime
= dir
->i_ctime
= CURRENT_TIME_SEC
;
194 /* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
195 * trick to fool GNU find's optimizations. If we can't be sure of the link
196 * (because of volume mount points) we set i_nlink to 1 which forces find
197 * to consider every child as a possible directory. We should also never
198 * see an increment or decrement for deleted directories where i_nlink == 0 */
199 static inline void coda_dir_inc_nlink(struct inode
*dir
)
201 if (dir
->i_nlink
>= 2)
205 static inline void coda_dir_drop_nlink(struct inode
*dir
)
207 if (dir
->i_nlink
> 2)
211 /* creation routines: create, mknod, mkdir, link, symlink */
212 static int coda_create(struct inode
*dir
, struct dentry
*de
, int mode
, struct nameidata
*nd
)
215 const char *name
=de
->d_name
.name
;
216 int length
=de
->d_name
.len
;
218 struct CodaFid newfid
;
219 struct coda_vattr attrs
;
222 coda_vfs_stat
.create
++;
224 if (coda_isroot(dir
) && coda_iscontrol(name
, length
)) {
229 error
= venus_create(dir
->i_sb
, coda_i2f(dir
), name
, length
,
230 0, mode
, &newfid
, &attrs
);
238 inode
= coda_iget(dir
->i_sb
, &newfid
, &attrs
);
239 if ( IS_ERR(inode
) ) {
242 return PTR_ERR(inode
);
245 /* invalidate the directory cnode's attributes */
246 coda_dir_update_mtime(dir
);
248 d_instantiate(de
, inode
);
252 static int coda_mkdir(struct inode
*dir
, struct dentry
*de
, int mode
)
255 struct coda_vattr attrs
;
256 const char *name
= de
->d_name
.name
;
257 int len
= de
->d_name
.len
;
259 struct CodaFid newfid
;
262 coda_vfs_stat
.mkdir
++;
264 if (coda_isroot(dir
) && coda_iscontrol(name
, len
)) {
269 attrs
.va_mode
= mode
;
270 error
= venus_mkdir(dir
->i_sb
, coda_i2f(dir
),
271 name
, len
, &newfid
, &attrs
);
279 inode
= coda_iget(dir
->i_sb
, &newfid
, &attrs
);
280 if ( IS_ERR(inode
) ) {
283 return PTR_ERR(inode
);
286 /* invalidate the directory cnode's attributes */
287 coda_dir_inc_nlink(dir
);
288 coda_dir_update_mtime(dir
);
290 d_instantiate(de
, inode
);
294 /* try to make de an entry in dir_inodde linked to source_de */
295 static int coda_link(struct dentry
*source_de
, struct inode
*dir_inode
,
298 struct inode
*inode
= source_de
->d_inode
;
299 const char * name
= de
->d_name
.name
;
300 int len
= de
->d_name
.len
;
304 coda_vfs_stat
.link
++;
306 if (coda_isroot(dir_inode
) && coda_iscontrol(name
, len
)) {
311 error
= venus_link(dir_inode
->i_sb
, coda_i2f(inode
),
312 coda_i2f(dir_inode
), (const char *)name
, len
);
319 coda_dir_update_mtime(dir_inode
);
320 atomic_inc(&inode
->i_count
);
321 d_instantiate(de
, inode
);
330 static int coda_symlink(struct inode
*dir_inode
, struct dentry
*de
,
333 const char *name
= de
->d_name
.name
;
334 int len
= de
->d_name
.len
;
339 coda_vfs_stat
.symlink
++;
341 if (coda_isroot(dir_inode
) && coda_iscontrol(name
, len
)) {
346 symlen
= strlen(symname
);
347 if ( symlen
> CODA_MAXPATHLEN
) {
349 return -ENAMETOOLONG
;
353 * This entry is now negative. Since we do not create
354 * an inode for the entry we have to drop it.
357 error
= venus_symlink(dir_inode
->i_sb
, coda_i2f(dir_inode
), name
, len
,
360 /* mtime is no good anymore */
362 coda_dir_update_mtime(dir_inode
);
368 /* destruction routines: unlink, rmdir */
369 int coda_unlink(struct inode
*dir
, struct dentry
*de
)
372 const char *name
= de
->d_name
.name
;
373 int len
= de
->d_name
.len
;
376 coda_vfs_stat
.unlink
++;
378 error
= venus_remove(dir
->i_sb
, coda_i2f(dir
), name
, len
);
384 coda_dir_update_mtime(dir
);
385 drop_nlink(de
->d_inode
);
390 int coda_rmdir(struct inode
*dir
, struct dentry
*de
)
392 const char *name
= de
->d_name
.name
;
393 int len
= de
->d_name
.len
;
397 coda_vfs_stat
.rmdir
++;
399 error
= venus_rmdir(dir
->i_sb
, coda_i2f(dir
), name
, len
);
401 /* VFS may delete the child */
403 de
->d_inode
->i_nlink
= 0;
405 /* fix the link count of the parent */
406 coda_dir_drop_nlink(dir
);
407 coda_dir_update_mtime(dir
);
414 static int coda_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
415 struct inode
*new_dir
, struct dentry
*new_dentry
)
417 const char *old_name
= old_dentry
->d_name
.name
;
418 const char *new_name
= new_dentry
->d_name
.name
;
419 int old_length
= old_dentry
->d_name
.len
;
420 int new_length
= new_dentry
->d_name
.len
;
424 coda_vfs_stat
.rename
++;
426 error
= venus_rename(old_dir
->i_sb
, coda_i2f(old_dir
),
427 coda_i2f(new_dir
), old_length
, new_length
,
428 (const char *) old_name
, (const char *)new_name
);
431 if ( new_dentry
->d_inode
) {
432 if ( S_ISDIR(new_dentry
->d_inode
->i_mode
) ) {
433 coda_dir_drop_nlink(old_dir
);
434 coda_dir_inc_nlink(new_dir
);
436 coda_dir_update_mtime(old_dir
);
437 coda_dir_update_mtime(new_dir
);
438 coda_flag_inode(new_dentry
->d_inode
, C_VATTR
);
440 coda_flag_inode(old_dir
, C_VATTR
);
441 coda_flag_inode(new_dir
, C_VATTR
);
450 /* file operations for directories */
451 int coda_readdir(struct file
*coda_file
, void *dirent
, filldir_t filldir
)
453 struct dentry
*coda_dentry
= coda_file
->f_path
.dentry
;
454 struct coda_file_info
*cfi
;
455 struct file
*host_file
;
456 struct inode
*host_inode
;
459 cfi
= CODA_FTOC(coda_file
);
460 BUG_ON(!cfi
|| cfi
->cfi_magic
!= CODA_MAGIC
);
461 host_file
= cfi
->cfi_container
;
463 coda_vfs_stat
.readdir
++;
465 host_inode
= host_file
->f_path
.dentry
->d_inode
;
466 mutex_lock(&host_inode
->i_mutex
);
467 host_file
->f_pos
= coda_file
->f_pos
;
469 if (!host_file
->f_op
->readdir
) {
470 /* Venus: we must read Venus dirents from the file */
471 ret
= coda_venus_readdir(host_file
, filldir
, dirent
, coda_dentry
);
473 /* potemkin case: we were handed a directory inode. */
474 /* Yuk, we can't call vfs_readdir because we are already
475 * holding the inode semaphore. */
477 if (!host_file
->f_op
|| !host_file
->f_op
->readdir
)
481 if (!IS_DEADDIR(host_inode
)) {
482 ret
= host_file
->f_op
->readdir(host_file
, dirent
, filldir
);
483 file_accessed(host_file
);
487 coda_file
->f_pos
= host_file
->f_pos
;
488 mutex_unlock(&host_inode
->i_mutex
);
493 static inline unsigned int CDT2DT(unsigned char cdt
)
498 case CDT_UNKNOWN
: dt
= DT_UNKNOWN
; break;
499 case CDT_FIFO
: dt
= DT_FIFO
; break;
500 case CDT_CHR
: dt
= DT_CHR
; break;
501 case CDT_DIR
: dt
= DT_DIR
; break;
502 case CDT_BLK
: dt
= DT_BLK
; break;
503 case CDT_REG
: dt
= DT_REG
; break;
504 case CDT_LNK
: dt
= DT_LNK
; break;
505 case CDT_SOCK
: dt
= DT_SOCK
; break;
506 case CDT_WHT
: dt
= DT_WHT
; break;
507 default: dt
= DT_UNKNOWN
; break;
512 /* support routines */
513 static int coda_venus_readdir(struct file
*filp
, filldir_t filldir
,
514 void *dirent
, struct dentry
*dir
)
516 int result
= 0; /* # of entries returned */
517 struct venus_dirent
*vdir
;
518 unsigned long vdir_size
=
519 (unsigned long)(&((struct venus_dirent
*)0)->d_name
);
525 vdir
= kmalloc(sizeof(*vdir
), GFP_KERNEL
);
526 if (!vdir
) return -ENOMEM
;
531 ret
= filldir(dirent
, ".", 1, 0, dir
->d_inode
->i_ino
, DT_DIR
);
537 ret
= filldir(dirent
, "..", 2, 1, dir
->d_parent
->d_inode
->i_ino
, DT_DIR
);
544 /* read entries from the directory file */
545 ret
= kernel_read(filp
, filp
->f_pos
- 2, (char *)vdir
,
548 printk("coda_venus_readdir: read dir failed %d\n", ret
);
551 if (ret
== 0) break; /* end of directory file reached */
553 /* catch truncated reads */
554 if (ret
< vdir_size
|| ret
< vdir_size
+ vdir
->d_namlen
) {
555 printk("coda_venus_readdir: short read: %ld\n",
556 filp
->f_path
.dentry
->d_inode
->i_ino
);
560 /* validate whether the directory file actually makes sense */
561 if (vdir
->d_reclen
< vdir_size
+ vdir
->d_namlen
) {
562 printk("coda_venus_readdir: Invalid dir: %ld\n",
563 filp
->f_path
.dentry
->d_inode
->i_ino
);
568 name
.len
= vdir
->d_namlen
;
569 name
.name
= vdir
->d_name
;
571 /* Make sure we skip '.' and '..', we already got those */
572 if (name
.name
[0] == '.' && (name
.len
== 1 ||
573 (vdir
->d_name
[1] == '.' && name
.len
== 2)))
574 vdir
->d_fileno
= name
.len
= 0;
576 /* skip null entries */
577 if (vdir
->d_fileno
&& name
.len
) {
578 /* try to look up this entry in the dcache, that way
579 * userspace doesn't have to worry about breaking
580 * getcwd by having mismatched inode numbers for
581 * internal volume mountpoints. */
582 ino
= find_inode_number(dir
, &name
);
583 if (!ino
) ino
= vdir
->d_fileno
;
585 type
= CDT2DT(vdir
->d_type
);
586 ret
= filldir(dirent
, name
.name
, name
.len
, filp
->f_pos
,
588 /* failure means no space for filling in this round */
592 /* we'll always have progress because d_reclen is unsigned and
593 * we've already established it is non-zero. */
594 filp
->f_pos
+= vdir
->d_reclen
;
598 return result
? result
: ret
;
601 /* called when a cache lookup succeeds */
602 static int coda_dentry_revalidate(struct dentry
*de
, struct nameidata
*nd
)
604 struct inode
*inode
= de
->d_inode
;
605 struct coda_inode_info
*cii
;
610 if (coda_isroot(inode
))
612 if (is_bad_inode(inode
))
615 cii
= ITOC(de
->d_inode
);
616 if (!(cii
->c_flags
& (C_PURGE
| C_FLUSH
)))
619 shrink_dcache_parent(de
);
621 /* propagate for a flush */
622 if (cii
->c_flags
& C_FLUSH
)
623 coda_flag_inode_children(inode
, C_FLUSH
);
625 if (atomic_read(&de
->d_count
) > 1)
626 /* pretend it's valid, but don't change the flags */
629 /* clear the flags. */
630 cii
->c_flags
&= ~(C_VATTR
| C_PURGE
| C_FLUSH
);
641 * This is the callback from dput() when d_count is going to 0.
642 * We use this to unhash dentries with bad inodes.
644 static int coda_dentry_delete(struct dentry
* dentry
)
648 if (!dentry
->d_inode
)
651 flags
= (ITOC(dentry
->d_inode
)->c_flags
) & C_PURGE
;
652 if (is_bad_inode(dentry
->d_inode
) || flags
) {
661 * This is called when we want to check if the inode has
662 * changed on the server. Coda makes this easy since the
663 * cache manager Venus issues a downcall to the kernel when this
666 int coda_revalidate_inode(struct dentry
*dentry
)
668 struct coda_vattr attr
;
672 struct inode
*inode
= dentry
->d_inode
;
673 struct coda_inode_info
*cii
= ITOC(inode
);
679 if (cii
->c_flags
& (C_VATTR
| C_PURGE
| C_FLUSH
)) {
680 error
= venus_getattr(inode
->i_sb
, &(cii
->c_fid
), &attr
);
684 /* this inode may be lost if:
686 - type changes must be permitted for repair and
687 missing mount points.
689 old_mode
= inode
->i_mode
;
690 old_ino
= inode
->i_ino
;
691 coda_vattr_to_iattr(inode
, &attr
);
693 if ((old_mode
& S_IFMT
) != (inode
->i_mode
& S_IFMT
)) {
694 printk("Coda: inode %ld, fid %s changed type!\n",
695 inode
->i_ino
, coda_f2s(&(cii
->c_fid
)));
698 /* the following can happen when a local fid is replaced
699 with a global one, here we lose and declare the inode bad */
700 if (inode
->i_ino
!= old_ino
)
703 coda_flag_inode_children(inode
, C_FLUSH
);
704 cii
->c_flags
&= ~(C_VATTR
| C_PURGE
| C_FLUSH
);