1 /* -*- linux-c -*- --------------------------------------------------------- *
3 * linux/fs/autofs/root.c
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
7 * This file is part of the Linux kernel and is made available under
8 * the terms of the GNU General Public License, version 2, or at your
9 * option, any later version, incorporated herein by reference.
11 * ------------------------------------------------------------------------- */
13 #include <linux/errno.h>
14 #include <linux/stat.h>
15 #include <linux/param.h>
16 #include <linux/sched.h>
17 #include <linux/smp_lock.h>
20 static int autofs_root_readdir(struct file *,void *,filldir_t);
21 static struct dentry *autofs_root_lookup(struct inode *,struct dentry *);
22 static int autofs_root_symlink(struct inode *,struct dentry *,const char *);
23 static int autofs_root_unlink(struct inode *,struct dentry *);
24 static int autofs_root_rmdir(struct inode *,struct dentry *);
25 static int autofs_root_mkdir(struct inode *,struct dentry *,int);
26 static int autofs_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
28 struct file_operations autofs_root_operations = {
29 read: generic_read_dir,
30 readdir: autofs_root_readdir,
31 ioctl: autofs_root_ioctl,
34 struct inode_operations autofs_root_inode_operations = {
35 lookup: autofs_root_lookup,
36 unlink: autofs_root_unlink,
37 symlink: autofs_root_symlink,
38 mkdir: autofs_root_mkdir,
39 rmdir: autofs_root_rmdir,
42 static int autofs_root_readdir(struct file *filp, void *dirent, filldir_t filldir)
44 struct autofs_dir_ent *ent = NULL;
45 struct autofs_dirhash *dirhash;
46 struct autofs_sb_info *sbi;
47 struct inode * inode = filp->f_dentry->d_inode;
50 sbi = autofs_sbi(inode->i_sb);
51 dirhash = &sbi->dirhash;
57 if (filldir(dirent, ".", 1, nr, inode->i_ino, DT_DIR) < 0)
62 if (filldir(dirent, "..", 2, nr, inode->i_ino, DT_DIR) < 0)
67 while ( onr = nr, ent = autofs_hash_enum(dirhash,&nr,ent) ) {
68 if ( !ent->dentry || d_mountpoint(ent->dentry) ) {
69 if (filldir(dirent,ent->name,ent->len,onr,ent->ino,DT_UNKNOWN) < 0)
80 static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, struct autofs_sb_info *sbi)
83 struct autofs_dir_ent *ent;
86 if ( !(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)) ) {
88 if ( status && dentry->d_inode ) {
89 if ( status != -ENOENT )
90 printk("autofs warning: lookup failure on positive dentry, status = %d, name = %s\n", status, dentry->d_name.name);
91 return 0; /* Try to get the kernel to invalidate this dentry */
94 /* Turn this into a real negative dentry? */
95 if (status == -ENOENT) {
96 dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
97 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
100 /* Return a negative dentry, but leave it "pending" */
103 status = autofs_wait(sbi, &dentry->d_name);
104 } while (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)) );
107 /* Abuse this field as a pointer to the directory entry, used to
108 find the expire list pointers */
109 dentry->d_time = (unsigned long) ent;
111 if (!dentry->d_inode) {
112 inode = iget(sb, ent->ino);
114 /* Failed, but leave pending for next time */
117 dentry->d_inode = inode;
120 /* If this is a directory that isn't a mount point, bitch at the
121 daemon and fix it in user space */
122 if ( S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) ) {
123 return !autofs_wait(sbi, &dentry->d_name);
126 /* We don't update the usages for the autofs daemon itself, this
127 is necessary for recursive autofs mounts */
128 if ( !autofs_oz_mode(sbi) ) {
129 autofs_update_usage(&sbi->dirhash,ent);
132 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
138 * Revalidate is called on every cache lookup. Some of those
139 * cache lookups may actually happen while the dentry is not
140 * yet completely filled in, and revalidate has to delay such
143 static int autofs_revalidate(struct dentry * dentry, int flags)
146 struct autofs_sb_info *sbi;
147 struct autofs_dir_ent *ent;
151 dir = dentry->d_parent->d_inode;
152 sbi = autofs_sbi(dir->i_sb);
155 if ( dentry->d_flags & DCACHE_AUTOFS_PENDING ) {
156 if (autofs_oz_mode(sbi))
159 res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
164 /* Negative dentry.. invalidate if "old" */
165 if (!dentry->d_inode) {
167 return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
170 /* Check for a non-mountpoint directory */
171 if ( S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) ) {
172 if (autofs_oz_mode(sbi))
175 res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
180 /* Update the usage list */
181 if ( !autofs_oz_mode(sbi) ) {
182 ent = (struct autofs_dir_ent *) dentry->d_time;
184 autofs_update_usage(&sbi->dirhash,ent);
190 static struct dentry_operations autofs_dentry_operations = {
191 d_revalidate: autofs_revalidate,
194 static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentry)
196 struct autofs_sb_info *sbi;
199 DPRINTK(("autofs_root_lookup: name = "));
200 autofs_say(dentry->d_name.name,dentry->d_name.len);
202 if (dentry->d_name.len > NAME_MAX)
203 return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
205 sbi = autofs_sbi(dir->i_sb);
207 oz_mode = autofs_oz_mode(sbi);
208 DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
209 current->pid, current->pgrp, sbi->catatonic, oz_mode));
212 * Mark the dentry incomplete, but add it. This is needed so
213 * that the VFS layer knows about the dentry, and we can count
214 * on catching any lookups through the revalidate.
216 * Let all the hard work be done by the revalidate function that
217 * needs to be able to do this anyway..
219 * We need to do this before we release the directory semaphore.
221 dentry->d_op = &autofs_dentry_operations;
222 dentry->d_flags |= DCACHE_AUTOFS_PENDING;
226 autofs_revalidate(dentry, 0);
230 * If we are still pending, check if we had to handle
231 * a signal. If so we can force a restart..
233 if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
234 if (signal_pending(current))
235 return ERR_PTR(-ERESTARTNOINTR);
239 * If this dentry is unhashed, then we shouldn't honour this
240 * lookup even if the dentry is positive. Returning ENOENT here
241 * doesn't do the right thing for all system calls, but it should
242 * be OK for the operations we permit from an autofs.
244 if ( dentry->d_inode && d_unhashed(dentry) )
245 return ERR_PTR(-ENOENT);
250 static int autofs_root_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
252 struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
253 struct autofs_dirhash *dh = &sbi->dirhash;
254 struct autofs_dir_ent *ent;
257 struct autofs_symlink *sl;
259 DPRINTK(("autofs_root_symlink: %s <- ", symname));
260 autofs_say(dentry->d_name.name,dentry->d_name.len);
262 if ( !autofs_oz_mode(sbi) )
265 if ( autofs_hash_lookup(dh, &dentry->d_name) )
268 n = find_first_zero_bit(sbi->symlink_bitmap,AUTOFS_MAX_SYMLINKS);
269 if ( n >= AUTOFS_MAX_SYMLINKS )
272 set_bit(n,sbi->symlink_bitmap);
273 sl = &sbi->symlink[n];
274 sl->len = strlen(symname);
275 sl->data = kmalloc(slsize = sl->len+1, GFP_KERNEL);
277 clear_bit(n,sbi->symlink_bitmap);
281 ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
284 clear_bit(n,sbi->symlink_bitmap);
288 ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
292 clear_bit(n,sbi->symlink_bitmap);
296 memcpy(sl->data,symname,slsize);
297 sl->mtime = CURRENT_TIME;
299 ent->ino = AUTOFS_FIRST_SYMLINK + n;
300 ent->hash = dentry->d_name.hash;
301 memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
302 ent->dentry = NULL; /* We don't keep the dentry for symlinks */
304 autofs_hash_insert(dh,ent);
305 d_instantiate(dentry, iget(dir->i_sb,ent->ino));
313 * Normal filesystems would do a "d_delete()" to tell the VFS dcache
314 * that the file no longer exists. However, doing that means that the
315 * VFS layer can turn the dentry into a negative dentry, which we
316 * obviously do not want (we're dropping the entry not because it
317 * doesn't exist, but because it has timed out).
319 * Also see autofs_root_rmdir()..
321 static int autofs_root_unlink(struct inode *dir, struct dentry *dentry)
323 struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
324 struct autofs_dirhash *dh = &sbi->dirhash;
325 struct autofs_dir_ent *ent;
328 /* This allows root to remove symlinks */
329 if ( !autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
332 ent = autofs_hash_lookup(dh, &dentry->d_name);
336 n = ent->ino - AUTOFS_FIRST_SYMLINK;
337 if ( n >= AUTOFS_MAX_SYMLINKS )
338 return -EISDIR; /* It's a directory, dummy */
339 if ( !test_bit(n,sbi->symlink_bitmap) )
340 return -EINVAL; /* Nonexistent symlink? Shouldn't happen */
342 dentry->d_time = (unsigned long)(struct autofs_dirhash *)NULL;
343 autofs_hash_delete(ent);
344 clear_bit(n,sbi->symlink_bitmap);
345 kfree(sbi->symlink[n].data);
351 static int autofs_root_rmdir(struct inode *dir, struct dentry *dentry)
353 struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
354 struct autofs_dirhash *dh = &sbi->dirhash;
355 struct autofs_dir_ent *ent;
357 if ( !autofs_oz_mode(sbi) )
360 ent = autofs_hash_lookup(dh, &dentry->d_name);
364 if ( (unsigned int)ent->ino < AUTOFS_FIRST_DIR_INO )
365 return -ENOTDIR; /* Not a directory */
367 if ( ent->dentry != dentry ) {
368 printk("autofs_rmdir: odentry != dentry for entry %s\n", dentry->d_name.name);
371 dentry->d_time = (unsigned long)(struct autofs_dir_ent *)NULL;
372 autofs_hash_delete(ent);
379 static int autofs_root_mkdir(struct inode *dir, struct dentry *dentry, int mode)
381 struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
382 struct autofs_dirhash *dh = &sbi->dirhash;
383 struct autofs_dir_ent *ent;
386 if ( !autofs_oz_mode(sbi) )
389 ent = autofs_hash_lookup(dh, &dentry->d_name);
393 if ( sbi->next_dir_ino < AUTOFS_FIRST_DIR_INO ) {
394 printk("autofs: Out of inode numbers -- what the heck did you do??\n");
397 ino = sbi->next_dir_ino++;
399 ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
403 ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
409 ent->hash = dentry->d_name.hash;
410 memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
412 ent->dentry = dentry;
413 autofs_hash_insert(dh,ent);
416 d_instantiate(dentry, iget(dir->i_sb,ino));
421 /* Get/set timeout ioctl() operation */
422 static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi,
425 unsigned long ntimeout;
427 if (get_user(ntimeout, p) ||
428 put_user(sbi->exp_timeout / HZ, p))
431 if ( ntimeout > ULONG_MAX/HZ )
432 sbi->exp_timeout = 0;
434 sbi->exp_timeout = ntimeout * HZ;
439 /* Return protocol version */
440 static inline int autofs_get_protover(int *p)
442 return put_user(AUTOFS_PROTO_VERSION, p);
445 /* Perform an expiry operation */
446 static inline int autofs_expire_run(struct super_block *sb,
447 struct autofs_sb_info *sbi,
448 struct vfsmount *mnt,
449 struct autofs_packet_expire *pkt_p)
451 struct autofs_dir_ent *ent;
452 struct autofs_packet_expire pkt;
454 memset(&pkt,0,sizeof pkt);
456 pkt.hdr.proto_version = AUTOFS_PROTO_VERSION;
457 pkt.hdr.type = autofs_ptype_expire;
459 if ( !sbi->exp_timeout ||
460 !(ent = autofs_expire(sb,sbi,mnt)) )
464 memcpy(pkt.name, ent->name, pkt.len);
465 pkt.name[pkt.len] = '\0';
467 if ( copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)) )
474 * ioctl()'s on the root directory is the chief method for the daemon to
475 * generate kernel reactions
477 static int autofs_root_ioctl(struct inode *inode, struct file *filp,
478 unsigned int cmd, unsigned long arg)
480 struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
482 DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,current->pgrp));
484 if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
485 _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT )
488 if ( !autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
492 case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
493 return autofs_wait_release(sbi,(autofs_wqt_t)arg,0);
494 case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
495 return autofs_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
496 case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
497 autofs_catatonic_mode(sbi);
499 case AUTOFS_IOC_PROTOVER: /* Get protocol version */
500 return autofs_get_protover((int *)arg);
501 case AUTOFS_IOC_SETTIMEOUT:
502 return autofs_get_set_timeout(sbi,(unsigned long *)arg);
503 case AUTOFS_IOC_EXPIRE:
504 return autofs_expire_run(inode->i_sb, sbi, filp->f_vfsmnt,
505 (struct autofs_packet_expire *)arg);