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);