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, umode_t mode, bool excl);
34 static struct dentry *coda_lookup(struct inode *dir, struct dentry *target, unsigned int flags);
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, umode_t 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, struct dir_context *ctx);
49 static int coda_dentry_revalidate(struct dentry *de, unsigned int flags);
50 static int coda_dentry_delete(const struct dentry *);
52 /* support routines */
53 static int coda_venus_readdir(struct file *, struct dir_context *);
55 /* same as fs/bad_inode.c */
56 static int coda_return_EIO(void)
60 #define CODA_EIO_ERROR ((void *) (coda_return_EIO))
62 const struct dentry_operations coda_dentry_operations =
64 .d_revalidate = coda_dentry_revalidate,
65 .d_delete = coda_dentry_delete,
68 const struct inode_operations coda_dir_inode_operations =
70 .create = coda_create,
71 .lookup = coda_lookup,
73 .unlink = coda_unlink,
74 .symlink = coda_symlink,
77 .mknod = CODA_EIO_ERROR,
78 .rename = coda_rename,
79 .permission = coda_permission,
80 .getattr = coda_getattr,
81 .setattr = coda_setattr,
84 const struct file_operations coda_dir_operations = {
85 .llseek = generic_file_llseek,
86 .read = generic_read_dir,
87 .iterate = coda_readdir,
89 .release = coda_release,
94 /* inode operations for directories */
95 /* access routines: lookup, readlink, permission */
96 static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, unsigned int flags)
98 struct super_block *sb = dir->i_sb;
99 const char *name = entry->d_name.name;
100 size_t length = entry->d_name.len;
104 if (length > CODA_MAXNAMLEN) {
105 pr_err("name too long: lookup, %s (%*s)\n",
106 coda_i2s(dir), (int)length, name);
107 return ERR_PTR(-ENAMETOOLONG);
110 /* control object, create inode on the fly */
111 if (coda_isroot(dir) && coda_iscontrol(name, length)) {
112 inode = coda_cnode_makectl(sb);
115 struct CodaFid fid = { { 0, } };
116 int error = venus_lookup(sb, coda_i2f(dir), name, length,
118 inode = !error ? coda_cnode_make(&fid, sb) : ERR_PTR(error);
121 if (!IS_ERR(inode) && (type & CODA_NOCACHE))
122 coda_flag_inode(inode, C_VATTR | C_PURGE);
124 if (inode == ERR_PTR(-ENOENT))
127 return d_splice_alias(inode, entry);
131 int coda_permission(struct inode *inode, int mask)
135 if (mask & MAY_NOT_BLOCK)
138 mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
143 if ((mask & MAY_EXEC) && !execute_ok(inode))
146 if (coda_cache_check(inode, mask))
149 error = venus_access(inode->i_sb, coda_i2f(inode), mask);
152 coda_cache_enter(inode, mask);
158 static inline void coda_dir_update_mtime(struct inode *dir)
160 #ifdef REQUERY_VENUS_FOR_MTIME
161 /* invalidate the directory cnode's attributes so we refetch the
162 * attributes from venus next time the inode is referenced */
163 coda_flag_inode(dir, C_VATTR);
165 /* optimistically we can also act as if our nose bleeds. The
166 * granularity of the mtime is coarse anyways so we might actually be
167 * right most of the time. Note: we only do this for directories. */
168 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
172 /* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
173 * trick to fool GNU find's optimizations. If we can't be sure of the link
174 * (because of volume mount points) we set i_nlink to 1 which forces find
175 * to consider every child as a possible directory. We should also never
176 * see an increment or decrement for deleted directories where i_nlink == 0 */
177 static inline void coda_dir_inc_nlink(struct inode *dir)
179 if (dir->i_nlink >= 2)
183 static inline void coda_dir_drop_nlink(struct inode *dir)
185 if (dir->i_nlink > 2)
189 /* creation routines: create, mknod, mkdir, link, symlink */
190 static int coda_create(struct inode *dir, struct dentry *de, umode_t mode, bool excl)
193 const char *name=de->d_name.name;
194 int length=de->d_name.len;
196 struct CodaFid newfid;
197 struct coda_vattr attrs;
199 if (coda_isroot(dir) && coda_iscontrol(name, length))
202 error = venus_create(dir->i_sb, coda_i2f(dir), name, length,
203 0, mode, &newfid, &attrs);
207 inode = coda_iget(dir->i_sb, &newfid, &attrs);
209 error = PTR_ERR(inode);
213 /* invalidate the directory cnode's attributes */
214 coda_dir_update_mtime(dir);
215 d_instantiate(de, inode);
222 static int coda_mkdir(struct inode *dir, struct dentry *de, umode_t mode)
225 struct coda_vattr attrs;
226 const char *name = de->d_name.name;
227 int len = de->d_name.len;
229 struct CodaFid newfid;
231 if (coda_isroot(dir) && coda_iscontrol(name, len))
234 attrs.va_mode = mode;
235 error = venus_mkdir(dir->i_sb, coda_i2f(dir),
236 name, len, &newfid, &attrs);
240 inode = coda_iget(dir->i_sb, &newfid, &attrs);
242 error = PTR_ERR(inode);
246 /* invalidate the directory cnode's attributes */
247 coda_dir_inc_nlink(dir);
248 coda_dir_update_mtime(dir);
249 d_instantiate(de, inode);
256 /* try to make de an entry in dir_inodde linked to source_de */
257 static int coda_link(struct dentry *source_de, struct inode *dir_inode,
260 struct inode *inode = source_de->d_inode;
261 const char * name = de->d_name.name;
262 int len = de->d_name.len;
265 if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
268 error = venus_link(dir_inode->i_sb, coda_i2f(inode),
269 coda_i2f(dir_inode), (const char *)name, len);
275 coda_dir_update_mtime(dir_inode);
277 d_instantiate(de, inode);
283 static int coda_symlink(struct inode *dir_inode, struct dentry *de,
286 const char *name = de->d_name.name;
287 int len = de->d_name.len;
291 if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
294 symlen = strlen(symname);
295 if (symlen > CODA_MAXPATHLEN)
296 return -ENAMETOOLONG;
299 * This entry is now negative. Since we do not create
300 * an inode for the entry we have to drop it.
303 error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
306 /* mtime is no good anymore */
308 coda_dir_update_mtime(dir_inode);
313 /* destruction routines: unlink, rmdir */
314 static int coda_unlink(struct inode *dir, struct dentry *de)
317 const char *name = de->d_name.name;
318 int len = de->d_name.len;
320 error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
324 coda_dir_update_mtime(dir);
325 drop_nlink(de->d_inode);
329 static int coda_rmdir(struct inode *dir, struct dentry *de)
331 const char *name = de->d_name.name;
332 int len = de->d_name.len;
335 error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
337 /* VFS may delete the child */
339 clear_nlink(de->d_inode);
341 /* fix the link count of the parent */
342 coda_dir_drop_nlink(dir);
343 coda_dir_update_mtime(dir);
349 static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
350 struct inode *new_dir, struct dentry *new_dentry)
352 const char *old_name = old_dentry->d_name.name;
353 const char *new_name = new_dentry->d_name.name;
354 int old_length = old_dentry->d_name.len;
355 int new_length = new_dentry->d_name.len;
358 error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
359 coda_i2f(new_dir), old_length, new_length,
360 (const char *) old_name, (const char *)new_name);
362 if (new_dentry->d_inode) {
363 if (S_ISDIR(new_dentry->d_inode->i_mode)) {
364 coda_dir_drop_nlink(old_dir);
365 coda_dir_inc_nlink(new_dir);
367 coda_dir_update_mtime(old_dir);
368 coda_dir_update_mtime(new_dir);
369 coda_flag_inode(new_dentry->d_inode, C_VATTR);
371 coda_flag_inode(old_dir, C_VATTR);
372 coda_flag_inode(new_dir, C_VATTR);
379 /* file operations for directories */
380 static int coda_readdir(struct file *coda_file, struct dir_context *ctx)
382 struct coda_file_info *cfi;
383 struct file *host_file;
386 cfi = CODA_FTOC(coda_file);
387 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
388 host_file = cfi->cfi_container;
390 if (host_file->f_op->iterate) {
391 struct inode *host_inode = file_inode(host_file);
392 mutex_lock(&host_inode->i_mutex);
394 if (!IS_DEADDIR(host_inode)) {
395 ret = host_file->f_op->iterate(host_file, ctx);
396 file_accessed(host_file);
398 mutex_unlock(&host_inode->i_mutex);
401 /* Venus: we must read Venus dirents from a file */
402 return coda_venus_readdir(coda_file, ctx);
405 static inline unsigned int CDT2DT(unsigned char cdt)
410 case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
411 case CDT_FIFO: dt = DT_FIFO; break;
412 case CDT_CHR: dt = DT_CHR; break;
413 case CDT_DIR: dt = DT_DIR; break;
414 case CDT_BLK: dt = DT_BLK; break;
415 case CDT_REG: dt = DT_REG; break;
416 case CDT_LNK: dt = DT_LNK; break;
417 case CDT_SOCK: dt = DT_SOCK; break;
418 case CDT_WHT: dt = DT_WHT; break;
419 default: dt = DT_UNKNOWN; break;
424 /* support routines */
425 static int coda_venus_readdir(struct file *coda_file, struct dir_context *ctx)
427 struct coda_file_info *cfi;
428 struct coda_inode_info *cii;
429 struct file *host_file;
431 struct venus_dirent *vdir;
432 unsigned long vdir_size = offsetof(struct venus_dirent, d_name);
438 cfi = CODA_FTOC(coda_file);
439 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
440 host_file = cfi->cfi_container;
442 de = coda_file->f_path.dentry;
443 cii = ITOC(de->d_inode);
445 vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
446 if (!vdir) return -ENOMEM;
448 if (!dir_emit_dots(coda_file, ctx))
452 /* read entries from the directory file */
453 ret = kernel_read(host_file, ctx->pos - 2, (char *)vdir,
456 pr_err("coda readdir: read dir %s failed %d\n",
457 coda_f2s(&cii->c_fid), ret);
460 if (ret == 0) break; /* end of directory file reached */
462 /* catch truncated reads */
463 if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) {
464 pr_err("coda readdir: short read on %s\n",
465 coda_f2s(&cii->c_fid));
469 /* validate whether the directory file actually makes sense */
470 if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
471 pr_err("coda readdir: invalid dir %s\n",
472 coda_f2s(&cii->c_fid));
477 name.len = vdir->d_namlen;
478 name.name = vdir->d_name;
480 /* Make sure we skip '.' and '..', we already got those */
481 if (name.name[0] == '.' && (name.len == 1 ||
482 (name.name[1] == '.' && name.len == 2)))
483 vdir->d_fileno = name.len = 0;
485 /* skip null entries */
486 if (vdir->d_fileno && name.len) {
487 ino = vdir->d_fileno;
488 type = CDT2DT(vdir->d_type);
489 if (!dir_emit(ctx, name.name, name.len, ino, type))
492 /* we'll always have progress because d_reclen is unsigned and
493 * we've already established it is non-zero. */
494 ctx->pos += vdir->d_reclen;
501 /* called when a cache lookup succeeds */
502 static int coda_dentry_revalidate(struct dentry *de, unsigned int flags)
505 struct coda_inode_info *cii;
507 if (flags & LOOKUP_RCU)
511 if (!inode || coda_isroot(inode))
513 if (is_bad_inode(inode))
516 cii = ITOC(de->d_inode);
517 if (!(cii->c_flags & (C_PURGE | C_FLUSH)))
520 shrink_dcache_parent(de);
522 /* propagate for a flush */
523 if (cii->c_flags & C_FLUSH)
524 coda_flag_inode_children(inode, C_FLUSH);
527 /* pretend it's valid, but don't change the flags */
530 /* clear the flags. */
531 spin_lock(&cii->c_lock);
532 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
533 spin_unlock(&cii->c_lock);
541 * This is the callback from dput() when d_count is going to 0.
542 * We use this to unhash dentries with bad inodes.
544 static int coda_dentry_delete(const struct dentry * dentry)
548 if (!dentry->d_inode)
551 flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE;
552 if (is_bad_inode(dentry->d_inode) || flags) {
561 * This is called when we want to check if the inode has
562 * changed on the server. Coda makes this easy since the
563 * cache manager Venus issues a downcall to the kernel when this
566 int coda_revalidate_inode(struct inode *inode)
568 struct coda_vattr attr;
572 struct coda_inode_info *cii = ITOC(inode);
577 if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) {
578 error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
582 /* this inode may be lost if:
584 - type changes must be permitted for repair and
585 missing mount points.
587 old_mode = inode->i_mode;
588 old_ino = inode->i_ino;
589 coda_vattr_to_iattr(inode, &attr);
591 if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
592 pr_warn("inode %ld, fid %s changed type!\n",
593 inode->i_ino, coda_f2s(&(cii->c_fid)));
596 /* the following can happen when a local fid is replaced
597 with a global one, here we lose and declare the inode bad */
598 if (inode->i_ino != old_ino)
601 coda_flag_inode_children(inode, C_FLUSH);
603 spin_lock(&cii->c_lock);
604 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
605 spin_unlock(&cii->c_lock);