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 *buf, 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 *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 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 *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);
122 error = venus_lookup(dir->i_sb, coda_i2f(dir), name, length,
125 error = coda_cnode_make(&inode, &resfid, dir->i_sb);
129 if (error && error != -ENOENT)
130 return ERR_PTR(error);
133 entry->d_op = &coda_dentry_operations;
135 if (inode && (type & CODA_NOCACHE))
136 coda_flag_inode(inode, C_VATTR | C_PURGE);
138 return d_splice_alias(inode, entry);
142 int coda_permission(struct inode *inode, int mask, struct nameidata *nd)
151 coda_vfs_stat.permission++;
153 if (coda_cache_check(inode, mask))
156 error = venus_access(inode->i_sb, coda_i2f(inode), mask);
159 coda_cache_enter(inode, mask);
167 static inline void coda_dir_update_mtime(struct inode *dir)
169 #ifdef REQUERY_VENUS_FOR_MTIME
170 /* invalidate the directory cnode's attributes so we refetch the
171 * attributes from venus next time the inode is referenced */
172 coda_flag_inode(dir, C_VATTR);
174 /* optimistically we can also act as if our nose bleeds. The
175 * granularity of the mtime is coarse anyways so we might actually be
176 * right most of the time. Note: we only do this for directories. */
177 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
181 /* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
182 * trick to fool GNU find's optimizations. If we can't be sure of the link
183 * (because of volume mount points) we set i_nlink to 1 which forces find
184 * to consider every child as a possible directory. We should also never
185 * see an increment or decrement for deleted directories where i_nlink == 0 */
186 static inline void coda_dir_inc_nlink(struct inode *dir)
188 if (dir->i_nlink >= 2)
192 static inline void coda_dir_drop_nlink(struct inode *dir)
194 if (dir->i_nlink > 2)
198 /* creation routines: create, mknod, mkdir, link, symlink */
199 static int coda_create(struct inode *dir, struct dentry *de, int mode, struct nameidata *nd)
202 const char *name=de->d_name.name;
203 int length=de->d_name.len;
205 struct CodaFid newfid;
206 struct coda_vattr attrs;
209 coda_vfs_stat.create++;
211 if (coda_isroot(dir) && coda_iscontrol(name, length)) {
216 error = venus_create(dir->i_sb, coda_i2f(dir), name, length,
217 0, mode, &newfid, &attrs);
225 inode = coda_iget(dir->i_sb, &newfid, &attrs);
226 if ( IS_ERR(inode) ) {
229 return PTR_ERR(inode);
232 /* invalidate the directory cnode's attributes */
233 coda_dir_update_mtime(dir);
235 d_instantiate(de, inode);
239 static int coda_mkdir(struct inode *dir, struct dentry *de, int mode)
242 struct coda_vattr attrs;
243 const char *name = de->d_name.name;
244 int len = de->d_name.len;
246 struct CodaFid newfid;
249 coda_vfs_stat.mkdir++;
251 if (coda_isroot(dir) && coda_iscontrol(name, len)) {
256 attrs.va_mode = mode;
257 error = venus_mkdir(dir->i_sb, coda_i2f(dir),
258 name, len, &newfid, &attrs);
266 inode = coda_iget(dir->i_sb, &newfid, &attrs);
267 if ( IS_ERR(inode) ) {
270 return PTR_ERR(inode);
273 /* invalidate the directory cnode's attributes */
274 coda_dir_inc_nlink(dir);
275 coda_dir_update_mtime(dir);
277 d_instantiate(de, inode);
281 /* try to make de an entry in dir_inodde linked to source_de */
282 static int coda_link(struct dentry *source_de, struct inode *dir_inode,
285 struct inode *inode = source_de->d_inode;
286 const char * name = de->d_name.name;
287 int len = de->d_name.len;
291 coda_vfs_stat.link++;
293 if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) {
298 error = venus_link(dir_inode->i_sb, coda_i2f(inode),
299 coda_i2f(dir_inode), (const char *)name, len);
306 coda_dir_update_mtime(dir_inode);
307 atomic_inc(&inode->i_count);
308 d_instantiate(de, inode);
317 static int coda_symlink(struct inode *dir_inode, struct dentry *de,
320 const char *name = de->d_name.name;
321 int len = de->d_name.len;
326 coda_vfs_stat.symlink++;
328 if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) {
333 symlen = strlen(symname);
334 if ( symlen > CODA_MAXPATHLEN ) {
336 return -ENAMETOOLONG;
340 * This entry is now negative. Since we do not create
341 * an inode for the entry we have to drop it.
344 error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
347 /* mtime is no good anymore */
349 coda_dir_update_mtime(dir_inode);
355 /* destruction routines: unlink, rmdir */
356 int coda_unlink(struct inode *dir, struct dentry *de)
359 const char *name = de->d_name.name;
360 int len = de->d_name.len;
363 coda_vfs_stat.unlink++;
365 error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
371 coda_dir_update_mtime(dir);
372 drop_nlink(de->d_inode);
377 int coda_rmdir(struct inode *dir, struct dentry *de)
379 const char *name = de->d_name.name;
380 int len = de->d_name.len;
384 coda_vfs_stat.rmdir++;
386 error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
388 /* VFS may delete the child */
390 de->d_inode->i_nlink = 0;
392 /* fix the link count of the parent */
393 coda_dir_drop_nlink(dir);
394 coda_dir_update_mtime(dir);
401 static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
402 struct inode *new_dir, struct dentry *new_dentry)
404 const char *old_name = old_dentry->d_name.name;
405 const char *new_name = new_dentry->d_name.name;
406 int old_length = old_dentry->d_name.len;
407 int new_length = new_dentry->d_name.len;
411 coda_vfs_stat.rename++;
413 error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
414 coda_i2f(new_dir), old_length, new_length,
415 (const char *) old_name, (const char *)new_name);
418 if ( new_dentry->d_inode ) {
419 if ( S_ISDIR(new_dentry->d_inode->i_mode) ) {
420 coda_dir_drop_nlink(old_dir);
421 coda_dir_inc_nlink(new_dir);
423 coda_dir_update_mtime(old_dir);
424 coda_dir_update_mtime(new_dir);
425 coda_flag_inode(new_dentry->d_inode, C_VATTR);
427 coda_flag_inode(old_dir, C_VATTR);
428 coda_flag_inode(new_dir, C_VATTR);
437 /* file operations for directories */
438 int coda_readdir(struct file *coda_file, void *buf, filldir_t filldir)
440 struct coda_file_info *cfi;
441 struct file *host_file;
444 cfi = CODA_FTOC(coda_file);
445 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
446 host_file = cfi->cfi_container;
448 coda_vfs_stat.readdir++;
450 if (!host_file->f_op)
453 if (host_file->f_op->readdir)
455 /* potemkin case: we were handed a directory inode.
456 * We can't use vfs_readdir because we have to keep the file
457 * position in sync between the coda_file and the host_file.
458 * and as such we need grab the inode mutex. */
459 struct inode *host_inode = host_file->f_path.dentry->d_inode;
461 mutex_lock(&host_inode->i_mutex);
462 host_file->f_pos = coda_file->f_pos;
465 if (!IS_DEADDIR(host_inode)) {
466 ret = host_file->f_op->readdir(host_file, buf, filldir);
467 file_accessed(host_file);
470 coda_file->f_pos = host_file->f_pos;
471 mutex_unlock(&host_inode->i_mutex);
473 else /* Venus: we must read Venus dirents from a file */
474 ret = coda_venus_readdir(coda_file, buf, filldir);
479 static inline unsigned int CDT2DT(unsigned char cdt)
484 case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
485 case CDT_FIFO: dt = DT_FIFO; break;
486 case CDT_CHR: dt = DT_CHR; break;
487 case CDT_DIR: dt = DT_DIR; break;
488 case CDT_BLK: dt = DT_BLK; break;
489 case CDT_REG: dt = DT_REG; break;
490 case CDT_LNK: dt = DT_LNK; break;
491 case CDT_SOCK: dt = DT_SOCK; break;
492 case CDT_WHT: dt = DT_WHT; break;
493 default: dt = DT_UNKNOWN; break;
498 /* support routines */
499 static int coda_venus_readdir(struct file *coda_file, void *buf,
502 int result = 0; /* # of entries returned */
503 struct coda_file_info *cfi;
504 struct coda_inode_info *cii;
505 struct file *host_file;
507 struct venus_dirent *vdir;
508 unsigned long vdir_size =
509 (unsigned long)(&((struct venus_dirent *)0)->d_name);
515 cfi = CODA_FTOC(coda_file);
516 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
517 host_file = cfi->cfi_container;
519 de = coda_file->f_path.dentry;
520 cii = ITOC(de->d_inode);
522 vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
523 if (!vdir) return -ENOMEM;
525 switch (coda_file->f_pos) {
527 ret = filldir(buf, ".", 1, 0, de->d_inode->i_ino, DT_DIR);
533 ret = filldir(buf, "..", 2, 1, de->d_parent->d_inode->i_ino, DT_DIR);
540 /* read entries from the directory file */
541 ret = kernel_read(host_file, coda_file->f_pos - 2, (char *)vdir,
544 printk(KERN_ERR "coda readdir: read dir %s failed %d\n",
545 coda_f2s(&cii->c_fid), ret);
548 if (ret == 0) break; /* end of directory file reached */
550 /* catch truncated reads */
551 if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) {
552 printk(KERN_ERR "coda readdir: short read on %s\n",
553 coda_f2s(&cii->c_fid));
557 /* validate whether the directory file actually makes sense */
558 if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
559 printk(KERN_ERR "coda readdir: invalid dir %s\n",
560 coda_f2s(&cii->c_fid));
565 name.len = vdir->d_namlen;
566 name.name = vdir->d_name;
568 /* Make sure we skip '.' and '..', we already got those */
569 if (name.name[0] == '.' && (name.len == 1 ||
570 (vdir->d_name[1] == '.' && name.len == 2)))
571 vdir->d_fileno = name.len = 0;
573 /* skip null entries */
574 if (vdir->d_fileno && name.len) {
575 /* try to look up this entry in the dcache, that way
576 * userspace doesn't have to worry about breaking
577 * getcwd by having mismatched inode numbers for
578 * internal volume mountpoints. */
579 ino = find_inode_number(de, &name);
580 if (!ino) ino = vdir->d_fileno;
582 type = CDT2DT(vdir->d_type);
583 ret = filldir(buf, name.name, name.len,
584 coda_file->f_pos, ino, type);
585 /* failure means no space for filling in this round */
589 /* we'll always have progress because d_reclen is unsigned and
590 * we've already established it is non-zero. */
591 coda_file->f_pos += vdir->d_reclen;
595 return result ? result : ret;
598 /* called when a cache lookup succeeds */
599 static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd)
601 struct inode *inode = de->d_inode;
602 struct coda_inode_info *cii;
607 if (coda_isroot(inode))
609 if (is_bad_inode(inode))
612 cii = ITOC(de->d_inode);
613 if (!(cii->c_flags & (C_PURGE | C_FLUSH)))
616 shrink_dcache_parent(de);
618 /* propagate for a flush */
619 if (cii->c_flags & C_FLUSH)
620 coda_flag_inode_children(inode, C_FLUSH);
622 if (atomic_read(&de->d_count) > 1)
623 /* pretend it's valid, but don't change the flags */
626 /* clear the flags. */
627 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
638 * This is the callback from dput() when d_count is going to 0.
639 * We use this to unhash dentries with bad inodes.
641 static int coda_dentry_delete(struct dentry * dentry)
645 if (!dentry->d_inode)
648 flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE;
649 if (is_bad_inode(dentry->d_inode) || flags) {
658 * This is called when we want to check if the inode has
659 * changed on the server. Coda makes this easy since the
660 * cache manager Venus issues a downcall to the kernel when this
663 int coda_revalidate_inode(struct dentry *dentry)
665 struct coda_vattr attr;
669 struct inode *inode = dentry->d_inode;
670 struct coda_inode_info *cii = ITOC(inode);
676 if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) {
677 error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
681 /* this inode may be lost if:
683 - type changes must be permitted for repair and
684 missing mount points.
686 old_mode = inode->i_mode;
687 old_ino = inode->i_ino;
688 coda_vattr_to_iattr(inode, &attr);
690 if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
691 printk("Coda: inode %ld, fid %s changed type!\n",
692 inode->i_ino, coda_f2s(&(cii->c_fid)));
695 /* the following can happen when a local fid is replaced
696 with a global one, here we lose and declare the inode bad */
697 if (inode->i_ino != old_ino)
700 coda_flag_inode_children(inode, C_FLUSH);
701 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);