Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
new file mode 100644
index 0000000..3765c04
--- /dev/null
+++ b/fs/autofs4/root.c
@@ -0,0 +1,808 @@
+/* -*- c -*- --------------------------------------------------------------- *
+ *
+ * linux/fs/autofs/root.c
+ *
+ * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
+ * Copyright 2001-2003 Ian Kent <raven@themaw.net>
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ *
+ * ------------------------------------------------------------------------- */
+
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/param.h>
+#include <linux/time.h>
+#include <linux/smp_lock.h>
+#include "autofs_i.h"
+
+static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
+static int autofs4_dir_unlink(struct inode *,struct dentry *);
+static int autofs4_dir_rmdir(struct inode *,struct dentry *);
+static int autofs4_dir_mkdir(struct inode *,struct dentry *,int);
+static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
+static int autofs4_dir_open(struct inode *inode, struct file *file);
+static int autofs4_dir_close(struct inode *inode, struct file *file);
+static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir);
+static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir);
+static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
+static int autofs4_dcache_readdir(struct file *, void *, filldir_t);
+
+struct file_operations autofs4_root_operations = {
+ .open = dcache_dir_open,
+ .release = dcache_dir_close,
+ .read = generic_read_dir,
+ .readdir = autofs4_root_readdir,
+ .ioctl = autofs4_root_ioctl,
+};
+
+struct file_operations autofs4_dir_operations = {
+ .open = autofs4_dir_open,
+ .release = autofs4_dir_close,
+ .read = generic_read_dir,
+ .readdir = autofs4_dir_readdir,
+};
+
+struct inode_operations autofs4_root_inode_operations = {
+ .lookup = autofs4_lookup,
+ .unlink = autofs4_dir_unlink,
+ .symlink = autofs4_dir_symlink,
+ .mkdir = autofs4_dir_mkdir,
+ .rmdir = autofs4_dir_rmdir,
+};
+
+struct inode_operations autofs4_dir_inode_operations = {
+ .lookup = autofs4_lookup,
+ .unlink = autofs4_dir_unlink,
+ .symlink = autofs4_dir_symlink,
+ .mkdir = autofs4_dir_mkdir,
+ .rmdir = autofs4_dir_rmdir,
+};
+
+static int autofs4_root_readdir(struct file *file, void *dirent,
+ filldir_t filldir)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(file->f_dentry->d_sb);
+ int oz_mode = autofs4_oz_mode(sbi);
+
+ DPRINTK("called, filp->f_pos = %lld", file->f_pos);
+
+ /*
+ * Don't set reghost flag if:
+ * 1) f_pos is larger than zero -- we've already been here.
+ * 2) we haven't even enabled reghosting in the 1st place.
+ * 3) this is the daemon doing a readdir
+ */
+ if (oz_mode && file->f_pos == 0 && sbi->reghost_enabled)
+ sbi->needs_reghost = 1;
+
+ DPRINTK("needs_reghost = %d", sbi->needs_reghost);
+
+ return autofs4_dcache_readdir(file, dirent, filldir);
+}
+
+/* Update usage from here to top of tree, so that scan of
+ top-level directories will give a useful result */
+static void autofs4_update_usage(struct dentry *dentry)
+{
+ struct dentry *top = dentry->d_sb->s_root;
+
+ spin_lock(&dcache_lock);
+ for(; dentry != top; dentry = dentry->d_parent) {
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+
+ if (ino) {
+ update_atime(dentry->d_inode);
+ ino->last_used = jiffies;
+ }
+ }
+ spin_unlock(&dcache_lock);
+}
+
+/*
+ * From 2.4 kernel readdir.c
+ */
+static int autofs4_dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
+{
+ int i;
+ struct dentry *dentry = filp->f_dentry;
+
+ i = filp->f_pos;
+ switch (i) {
+ case 0:
+ if (filldir(dirent, ".", 1, i, dentry->d_inode->i_ino, DT_DIR) < 0)
+ break;
+ i++;
+ filp->f_pos++;
+ /* fallthrough */
+ case 1:
+ if (filldir(dirent, "..", 2, i, dentry->d_parent->d_inode->i_ino, DT_DIR) < 0)
+ break;
+ i++;
+ filp->f_pos++;
+ /* fallthrough */
+ default: {
+ struct list_head *list;
+ int j = i-2;
+
+ spin_lock(&dcache_lock);
+ list = dentry->d_subdirs.next;
+
+ for (;;) {
+ if (list == &dentry->d_subdirs) {
+ spin_unlock(&dcache_lock);
+ return 0;
+ }
+ if (!j)
+ break;
+ j--;
+ list = list->next;
+ }
+
+ while(1) {
+ struct dentry *de = list_entry(list, struct dentry, d_child);
+
+ if (!d_unhashed(de) && de->d_inode) {
+ spin_unlock(&dcache_lock);
+ if (filldir(dirent, de->d_name.name, de->d_name.len, filp->f_pos, de->d_inode->i_ino, DT_UNKNOWN) < 0)
+ break;
+ spin_lock(&dcache_lock);
+ }
+ filp->f_pos++;
+ list = list->next;
+ if (list != &dentry->d_subdirs)
+ continue;
+ spin_unlock(&dcache_lock);
+ break;
+ }
+ }
+ }
+ return 0;
+}
+
+static int autofs4_dir_open(struct inode *inode, struct file *file)
+{
+ struct dentry *dentry = file->f_dentry;
+ struct vfsmount *mnt = file->f_vfsmnt;
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ int status;
+
+ DPRINTK("file=%p dentry=%p %.*s",
+ file, dentry, dentry->d_name.len, dentry->d_name.name);
+
+ if (autofs4_oz_mode(sbi))
+ goto out;
+
+ if (autofs4_ispending(dentry)) {
+ DPRINTK("dentry busy");
+ return -EBUSY;
+ }
+
+ if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) {
+ struct nameidata nd;
+ int empty;
+
+ /* In case there are stale directory dentrys from a failed mount */
+ spin_lock(&dcache_lock);
+ empty = list_empty(&dentry->d_subdirs);
+ spin_unlock(&dcache_lock);
+
+ if (!empty)
+ d_invalidate(dentry);
+
+ nd.flags = LOOKUP_DIRECTORY;
+ status = (dentry->d_op->d_revalidate)(dentry, &nd);
+
+ if (!status)
+ return -ENOENT;
+ }
+
+ if (d_mountpoint(dentry)) {
+ struct file *fp = NULL;
+ struct vfsmount *fp_mnt = mntget(mnt);
+ struct dentry *fp_dentry = dget(dentry);
+
+ while (follow_down(&fp_mnt, &fp_dentry) && d_mountpoint(fp_dentry));
+
+ fp = dentry_open(fp_dentry, fp_mnt, file->f_flags);
+ status = PTR_ERR(fp);
+ if (IS_ERR(fp)) {
+ file->private_data = NULL;
+ return status;
+ }
+ file->private_data = fp;
+ }
+out:
+ return 0;
+}
+
+static int autofs4_dir_close(struct inode *inode, struct file *file)
+{
+ struct dentry *dentry = file->f_dentry;
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+
+ DPRINTK("file=%p dentry=%p %.*s",
+ file, dentry, dentry->d_name.len, dentry->d_name.name);
+
+ if (autofs4_oz_mode(sbi))
+ goto out;
+
+ if (autofs4_ispending(dentry)) {
+ DPRINTK("dentry busy");
+ return -EBUSY;
+ }
+
+ if (d_mountpoint(dentry)) {
+ struct file *fp = file->private_data;
+
+ if (!fp)
+ return -ENOENT;
+
+ filp_close(fp, current->files);
+ file->private_data = NULL;
+ }
+out:
+ return 0;
+}
+
+static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir)
+{
+ struct dentry *dentry = file->f_dentry;
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ int status;
+
+ DPRINTK("file=%p dentry=%p %.*s",
+ file, dentry, dentry->d_name.len, dentry->d_name.name);
+
+ if (autofs4_oz_mode(sbi))
+ goto out;
+
+ if (autofs4_ispending(dentry)) {
+ DPRINTK("dentry busy");
+ return -EBUSY;
+ }
+
+ if (d_mountpoint(dentry)) {
+ struct file *fp = file->private_data;
+
+ if (!fp)
+ return -ENOENT;
+
+ if (!fp->f_op || !fp->f_op->readdir)
+ goto out;
+
+ status = vfs_readdir(fp, filldir, dirent);
+ file->f_pos = fp->f_pos;
+ if (status)
+ autofs4_copy_atime(file, fp);
+ return status;
+ }
+out:
+ return autofs4_dcache_readdir(file, dirent, filldir);
+}
+
+static int try_to_fill_dentry(struct dentry *dentry,
+ struct super_block *sb,
+ struct autofs_sb_info *sbi, int flags)
+{
+ struct autofs_info *de_info = autofs4_dentry_ino(dentry);
+ int status = 0;
+
+ /* Block on any pending expiry here; invalidate the dentry
+ when expiration is done to trigger mount request with a new
+ dentry */
+ if (de_info && (de_info->flags & AUTOFS_INF_EXPIRING)) {
+ DPRINTK("waiting for expire %p name=%.*s",
+ dentry, dentry->d_name.len, dentry->d_name.name);
+
+ status = autofs4_wait(sbi, dentry, NFY_NONE);
+
+ DPRINTK("expire done status=%d", status);
+
+ return 0;
+ }
+
+ DPRINTK("dentry=%p %.*s ino=%p",
+ dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
+
+ /* Wait for a pending mount, triggering one if there isn't one already */
+ if (dentry->d_inode == NULL) {
+ DPRINTK("waiting for mount name=%.*s",
+ dentry->d_name.len, dentry->d_name.name);
+
+ status = autofs4_wait(sbi, dentry, NFY_MOUNT);
+
+ DPRINTK("mount done status=%d", status);
+
+ if (status && dentry->d_inode)
+ return 0; /* Try to get the kernel to invalidate this dentry */
+
+ /* Turn this into a real negative dentry? */
+ if (status == -ENOENT) {
+ dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+ spin_unlock(&dentry->d_lock);
+ return 1;
+ } else if (status) {
+ /* Return a negative dentry, but leave it "pending" */
+ return 1;
+ }
+ /* Trigger mount for path component or follow link */
+ } else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) ||
+ current->link_count) {
+ DPRINTK("waiting for mount name=%.*s",
+ dentry->d_name.len, dentry->d_name.name);
+
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_AUTOFS_PENDING;
+ spin_unlock(&dentry->d_lock);
+ status = autofs4_wait(sbi, dentry, NFY_MOUNT);
+
+ DPRINTK("mount done status=%d", status);
+
+ if (status) {
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+ spin_unlock(&dentry->d_lock);
+ return 0;
+ }
+ }
+
+ /* We don't update the usages for the autofs daemon itself, this
+ is necessary for recursive autofs mounts */
+ if (!autofs4_oz_mode(sbi))
+ autofs4_update_usage(dentry);
+
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+ spin_unlock(&dentry->d_lock);
+ return 1;
+}
+
+/*
+ * Revalidate is called on every cache lookup. Some of those
+ * cache lookups may actually happen while the dentry is not
+ * yet completely filled in, and revalidate has to delay such
+ * lookups..
+ */
+static int autofs4_revalidate(struct dentry * dentry, struct nameidata *nd)
+{
+ struct inode * dir = dentry->d_parent->d_inode;
+ struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
+ int oz_mode = autofs4_oz_mode(sbi);
+ int flags = nd ? nd->flags : 0;
+ int status = 1;
+
+ /* Pending dentry */
+ if (autofs4_ispending(dentry)) {
+ if (!oz_mode)
+ status = try_to_fill_dentry(dentry, dir->i_sb, sbi, flags);
+ return status;
+ }
+
+ /* Negative dentry.. invalidate if "old" */
+ if (dentry->d_inode == NULL)
+ return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
+
+ /* Check for a non-mountpoint directory with no contents */
+ spin_lock(&dcache_lock);
+ if (S_ISDIR(dentry->d_inode->i_mode) &&
+ !d_mountpoint(dentry) &&
+ list_empty(&dentry->d_subdirs)) {
+ DPRINTK("dentry=%p %.*s, emptydir",
+ dentry, dentry->d_name.len, dentry->d_name.name);
+ spin_unlock(&dcache_lock);
+ if (!oz_mode)
+ status = try_to_fill_dentry(dentry, dir->i_sb, sbi, flags);
+ return status;
+ }
+ spin_unlock(&dcache_lock);
+
+ /* Update the usage list */
+ if (!oz_mode)
+ autofs4_update_usage(dentry);
+
+ return 1;
+}
+
+static void autofs4_dentry_release(struct dentry *de)
+{
+ struct autofs_info *inf;
+
+ DPRINTK("releasing %p", de);
+
+ inf = autofs4_dentry_ino(de);
+ de->d_fsdata = NULL;
+
+ if (inf) {
+ inf->dentry = NULL;
+ inf->inode = NULL;
+
+ autofs4_free_ino(inf);
+ }
+}
+
+/* For dentries of directories in the root dir */
+static struct dentry_operations autofs4_root_dentry_operations = {
+ .d_revalidate = autofs4_revalidate,
+ .d_release = autofs4_dentry_release,
+};
+
+/* For other dentries */
+static struct dentry_operations autofs4_dentry_operations = {
+ .d_revalidate = autofs4_revalidate,
+ .d_release = autofs4_dentry_release,
+};
+
+/* Lookups in the root directory */
+static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+{
+ struct autofs_sb_info *sbi;
+ int oz_mode;
+
+ DPRINTK("name = %.*s",
+ dentry->d_name.len, dentry->d_name.name);
+
+ if (dentry->d_name.len > NAME_MAX)
+ return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
+
+ sbi = autofs4_sbi(dir->i_sb);
+
+ oz_mode = autofs4_oz_mode(sbi);
+ DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
+ current->pid, process_group(current), sbi->catatonic, oz_mode);
+
+ /*
+ * Mark the dentry incomplete, but add it. This is needed so
+ * that the VFS layer knows about the dentry, and we can count
+ * on catching any lookups through the revalidate.
+ *
+ * Let all the hard work be done by the revalidate function that
+ * needs to be able to do this anyway..
+ *
+ * We need to do this before we release the directory semaphore.
+ */
+ dentry->d_op = &autofs4_root_dentry_operations;
+
+ if (!oz_mode) {
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_AUTOFS_PENDING;
+ spin_unlock(&dentry->d_lock);
+ }
+ dentry->d_fsdata = NULL;
+ d_add(dentry, NULL);
+
+ if (dentry->d_op && dentry->d_op->d_revalidate) {
+ up(&dir->i_sem);
+ (dentry->d_op->d_revalidate)(dentry, nd);
+ down(&dir->i_sem);
+ }
+
+ /*
+ * If we are still pending, check if we had to handle
+ * a signal. If so we can force a restart..
+ */
+ if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
+ /* See if we were interrupted */
+ if (signal_pending(current)) {
+ sigset_t *sigset = ¤t->pending.signal;
+ if (sigismember (sigset, SIGKILL) ||
+ sigismember (sigset, SIGQUIT) ||
+ sigismember (sigset, SIGINT)) {
+ return ERR_PTR(-ERESTARTNOINTR);
+ }
+ }
+ }
+
+ /*
+ * If this dentry is unhashed, then we shouldn't honour this
+ * lookup even if the dentry is positive. Returning ENOENT here
+ * doesn't do the right thing for all system calls, but it should
+ * be OK for the operations we permit from an autofs.
+ */
+ if ( dentry->d_inode && d_unhashed(dentry) )
+ return ERR_PTR(-ENOENT);
+
+ return NULL;
+}
+
+static int autofs4_dir_symlink(struct inode *dir,
+ struct dentry *dentry,
+ const char *symname)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ struct inode *inode;
+ char *cp;
+
+ DPRINTK("%s <- %.*s", symname,
+ dentry->d_name.len, dentry->d_name.name);
+
+ if (!autofs4_oz_mode(sbi))
+ return -EACCES;
+
+ ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555);
+ if (ino == NULL)
+ return -ENOSPC;
+
+ ino->size = strlen(symname);
+ ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL);
+
+ if (cp == NULL) {
+ kfree(ino);
+ return -ENOSPC;
+ }
+
+ strcpy(cp, symname);
+
+ inode = autofs4_get_inode(dir->i_sb, ino);
+ d_instantiate(dentry, inode);
+
+ if (dir == dir->i_sb->s_root->d_inode)
+ dentry->d_op = &autofs4_root_dentry_operations;
+ else
+ dentry->d_op = &autofs4_dentry_operations;
+
+ dentry->d_fsdata = ino;
+ ino->dentry = dget(dentry);
+ ino->inode = inode;
+
+ dir->i_mtime = CURRENT_TIME;
+
+ return 0;
+}
+
+/*
+ * NOTE!
+ *
+ * Normal filesystems would do a "d_delete()" to tell the VFS dcache
+ * that the file no longer exists. However, doing that means that the
+ * VFS layer can turn the dentry into a negative dentry. We don't want
+ * this, because since the unlink is probably the result of an expire.
+ * We simply d_drop it, which allows the dentry lookup to remount it
+ * if necessary.
+ *
+ * If a process is blocked on the dentry waiting for the expire to finish,
+ * it will invalidate the dentry and try to mount with a new one.
+ *
+ * Also see autofs4_dir_rmdir()..
+ */
+static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+
+ /* This allows root to remove symlinks */
+ if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
+ return -EACCES;
+
+ dput(ino->dentry);
+
+ dentry->d_inode->i_size = 0;
+ dentry->d_inode->i_nlink = 0;
+
+ dir->i_mtime = CURRENT_TIME;
+
+ d_drop(dentry);
+
+ return 0;
+}
+
+static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+
+ if (!autofs4_oz_mode(sbi))
+ return -EACCES;
+
+ spin_lock(&dcache_lock);
+ if (!list_empty(&dentry->d_subdirs)) {
+ spin_unlock(&dcache_lock);
+ return -ENOTEMPTY;
+ }
+ spin_lock(&dentry->d_lock);
+ __d_drop(dentry);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_lock);
+
+ dput(ino->dentry);
+
+ dentry->d_inode->i_size = 0;
+ dentry->d_inode->i_nlink = 0;
+
+ if (dir->i_nlink)
+ dir->i_nlink--;
+
+ return 0;
+}
+
+static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ struct inode *inode;
+
+ if ( !autofs4_oz_mode(sbi) )
+ return -EACCES;
+
+ DPRINTK("dentry %p, creating %.*s",
+ dentry, dentry->d_name.len, dentry->d_name.name);
+
+ ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
+ if (ino == NULL)
+ return -ENOSPC;
+
+ inode = autofs4_get_inode(dir->i_sb, ino);
+ d_instantiate(dentry, inode);
+
+ if (dir == dir->i_sb->s_root->d_inode)
+ dentry->d_op = &autofs4_root_dentry_operations;
+ else
+ dentry->d_op = &autofs4_dentry_operations;
+
+ dentry->d_fsdata = ino;
+ ino->dentry = dget(dentry);
+ ino->inode = inode;
+ dir->i_nlink++;
+ dir->i_mtime = CURRENT_TIME;
+
+ return 0;
+}
+
+/* Get/set timeout ioctl() operation */
+static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi,
+ unsigned long __user *p)
+{
+ int rv;
+ unsigned long ntimeout;
+
+ if ( (rv = get_user(ntimeout, p)) ||
+ (rv = put_user(sbi->exp_timeout/HZ, p)) )
+ return rv;
+
+ if ( ntimeout > ULONG_MAX/HZ )
+ sbi->exp_timeout = 0;
+ else
+ sbi->exp_timeout = ntimeout * HZ;
+
+ return 0;
+}
+
+/* Return protocol version */
+static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p)
+{
+ return put_user(sbi->version, p);
+}
+
+/* Return protocol sub version */
+static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p)
+{
+ return put_user(sbi->sub_version, p);
+}
+
+/*
+ * Tells the daemon whether we need to reghost or not. Also, clears
+ * the reghost_needed flag.
+ */
+static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p)
+{
+ int status;
+
+ DPRINTK("returning %d", sbi->needs_reghost);
+
+ status = put_user(sbi->needs_reghost, p);
+ if ( status )
+ return status;
+
+ sbi->needs_reghost = 0;
+ return 0;
+}
+
+/*
+ * Enable / Disable reghosting ioctl() operation
+ */
+static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p)
+{
+ int status;
+ int val;
+
+ status = get_user(val, p);
+
+ DPRINTK("reghost = %d", val);
+
+ if (status)
+ return status;
+
+ /* turn on/off reghosting, with the val */
+ sbi->reghost_enabled = val;
+ return 0;
+}
+
+/*
+* Tells the daemon whether it can umount the autofs mount.
+*/
+static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p)
+{
+ int status = 0;
+
+ if (may_umount(mnt) == 0)
+ status = 1;
+
+ DPRINTK("returning %d", status);
+
+ status = put_user(status, p);
+
+ return status;
+}
+
+/* Identify autofs4_dentries - this is so we can tell if there's
+ an extra dentry refcount or not. We only hold a refcount on the
+ dentry if its non-negative (ie, d_inode != NULL)
+*/
+int is_autofs4_dentry(struct dentry *dentry)
+{
+ return dentry && dentry->d_inode &&
+ (dentry->d_op == &autofs4_root_dentry_operations ||
+ dentry->d_op == &autofs4_dentry_operations) &&
+ dentry->d_fsdata != NULL;
+}
+
+/*
+ * ioctl()'s on the root directory is the chief method for the daemon to
+ * generate kernel reactions
+ */
+static int autofs4_root_ioctl(struct inode *inode, struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
+ void __user *p = (void __user *)arg;
+
+ DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u",
+ cmd,arg,sbi,process_group(current));
+
+ if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
+ _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT )
+ return -ENOTTY;
+
+ if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
+ return -EPERM;
+
+ switch(cmd) {
+ case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
+ return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0);
+ case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
+ return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
+ case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
+ autofs4_catatonic_mode(sbi);
+ return 0;
+ case AUTOFS_IOC_PROTOVER: /* Get protocol version */
+ return autofs4_get_protover(sbi, p);
+ case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
+ return autofs4_get_protosubver(sbi, p);
+ case AUTOFS_IOC_SETTIMEOUT:
+ return autofs4_get_set_timeout(sbi, p);
+
+ case AUTOFS_IOC_TOGGLEREGHOST:
+ return autofs4_toggle_reghost(sbi, p);
+ case AUTOFS_IOC_ASKREGHOST:
+ return autofs4_ask_reghost(sbi, p);
+
+ case AUTOFS_IOC_ASKUMOUNT:
+ return autofs4_ask_umount(filp->f_vfsmnt, p);
+
+ /* return a single thing to expire */
+ case AUTOFS_IOC_EXPIRE:
+ return autofs4_expire_run(inode->i_sb,filp->f_vfsmnt,sbi, p);
+ /* same as above, but can send multiple expires through pipe */
+ case AUTOFS_IOC_EXPIRE_MULTI:
+ return autofs4_expire_multi(inode->i_sb,filp->f_vfsmnt,sbi, p);
+
+ default:
+ return -ENOSYS;
+ }
+}