--- /dev/null
+/* -*- c -*- --------------------------------------------------------------- *
+ *
+ * linux/fs/autofs/root.c
+ *
+ * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
+ * Copyright 2001-2006 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/capability.h>
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+#include <linux/param.h>
+#include <linux/time.h>
+#include <linux/compat.h>
+#include <linux/mutex.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 *,umode_t);
+static long autofs4_root_ioctl(struct file *,unsigned int,unsigned long);
+#ifdef CONFIG_COMPAT
+static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long);
+#endif
+static int autofs4_dir_open(struct inode *inode, struct file *file);
+static struct dentry *autofs4_lookup(struct inode *,struct dentry *, unsigned int);
+static struct vfsmount *autofs4_d_automount(struct path *);
+static int autofs4_d_manage(struct dentry *, bool);
+static void autofs4_dentry_release(struct dentry *);
+
+const struct file_operations autofs4_root_operations = {
+ .open = dcache_dir_open,
+ .release = dcache_dir_close,
+ .read = generic_read_dir,
+ .iterate = dcache_readdir,
+ .llseek = dcache_dir_lseek,
+ .unlocked_ioctl = autofs4_root_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = autofs4_root_compat_ioctl,
+#endif
+};
+
+const struct file_operations autofs4_dir_operations = {
+ .open = autofs4_dir_open,
+ .release = dcache_dir_close,
+ .read = generic_read_dir,
+ .iterate = dcache_readdir,
+ .llseek = dcache_dir_lseek,
+};
+
+const 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,
+};
+
+const struct dentry_operations autofs4_dentry_operations = {
+ .d_automount = autofs4_d_automount,
+ .d_manage = autofs4_d_manage,
+ .d_release = autofs4_dentry_release,
+};
+
+static void autofs4_add_active(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ if (ino) {
+ spin_lock(&sbi->lookup_lock);
+ if (!ino->active_count) {
+ if (list_empty(&ino->active))
+ list_add(&ino->active, &sbi->active_list);
+ }
+ ino->active_count++;
+ spin_unlock(&sbi->lookup_lock);
+ }
+ return;
+}
+
+static void autofs4_del_active(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ if (ino) {
+ spin_lock(&sbi->lookup_lock);
+ ino->active_count--;
+ if (!ino->active_count) {
+ if (!list_empty(&ino->active))
+ list_del_init(&ino->active);
+ }
+ spin_unlock(&sbi->lookup_lock);
+ }
+ return;
+}
+
+static int autofs4_dir_open(struct inode *inode, struct file *file)
+{
+ struct dentry *dentry = file->f_path.dentry;
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+
+ DPRINTK("file=%p dentry=%p %pd", file, dentry, dentry);
+
+ if (autofs4_oz_mode(sbi))
+ goto out;
+
+ /*
+ * An empty directory in an autofs file system is always a
+ * mount point. The daemon must have failed to mount this
+ * during lookup so it doesn't exist. This can happen, for
+ * example, if user space returns an incorrect status for a
+ * mount request. Otherwise we're doing a readdir on the
+ * autofs file system so just let the libfs routines handle
+ * it.
+ */
+ spin_lock(&sbi->lookup_lock);
+ if (!d_mountpoint(dentry) && simple_empty(dentry)) {
+ spin_unlock(&sbi->lookup_lock);
+ return -ENOENT;
+ }
+ spin_unlock(&sbi->lookup_lock);
+
+out:
+ return dcache_dir_open(inode, file);
+}
+
+static void autofs4_dentry_release(struct dentry *de)
+{
+ struct autofs_info *ino = autofs4_dentry_ino(de);
+ struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
+
+ DPRINTK("releasing %p", de);
+
+ if (!ino)
+ return;
+
+ if (sbi) {
+ spin_lock(&sbi->lookup_lock);
+ if (!list_empty(&ino->active))
+ list_del(&ino->active);
+ if (!list_empty(&ino->expiring))
+ list_del(&ino->expiring);
+ spin_unlock(&sbi->lookup_lock);
+ }
+
+ autofs4_free_ino(ino);
+}
+
+static struct dentry *autofs4_lookup_active(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct dentry *parent = dentry->d_parent;
+ struct qstr *name = &dentry->d_name;
+ unsigned int len = name->len;
+ unsigned int hash = name->hash;
+ const unsigned char *str = name->name;
+ struct list_head *p, *head;
+
+ head = &sbi->active_list;
+ if (list_empty(head))
+ return NULL;
+ spin_lock(&sbi->lookup_lock);
+ list_for_each(p, head) {
+ struct autofs_info *ino;
+ struct dentry *active;
+ struct qstr *qstr;
+
+ ino = list_entry(p, struct autofs_info, active);
+ active = ino->dentry;
+
+ spin_lock(&active->d_lock);
+
+ /* Already gone? */
+ if ((int) d_count(active) <= 0)
+ goto next;
+
+ qstr = &active->d_name;
+
+ if (active->d_name.hash != hash)
+ goto next;
+ if (active->d_parent != parent)
+ goto next;
+
+ if (qstr->len != len)
+ goto next;
+ if (memcmp(qstr->name, str, len))
+ goto next;
+
+ if (d_unhashed(active)) {
+ dget_dlock(active);
+ spin_unlock(&active->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+ return active;
+ }
+next:
+ spin_unlock(&active->d_lock);
+ }
+ spin_unlock(&sbi->lookup_lock);
+
+ return NULL;
+}
+
+static struct dentry *autofs4_lookup_expiring(struct dentry *dentry,
+ bool rcu_walk)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct dentry *parent = dentry->d_parent;
+ struct qstr *name = &dentry->d_name;
+ unsigned int len = name->len;
+ unsigned int hash = name->hash;
+ const unsigned char *str = name->name;
+ struct list_head *p, *head;
+
+ head = &sbi->expiring_list;
+ if (list_empty(head))
+ return NULL;
+ spin_lock(&sbi->lookup_lock);
+ list_for_each(p, head) {
+ struct autofs_info *ino;
+ struct dentry *expiring;
+ struct qstr *qstr;
+
+ if (rcu_walk) {
+ spin_unlock(&sbi->lookup_lock);
+ return ERR_PTR(-ECHILD);
+ }
+
+ ino = list_entry(p, struct autofs_info, expiring);
+ expiring = ino->dentry;
+
+ spin_lock(&expiring->d_lock);
+
+ /* We've already been dentry_iput or unlinked */
+ if (d_really_is_negative(expiring))
+ goto next;
+
+ qstr = &expiring->d_name;
+
+ if (expiring->d_name.hash != hash)
+ goto next;
+ if (expiring->d_parent != parent)
+ goto next;
+
+ if (qstr->len != len)
+ goto next;
+ if (memcmp(qstr->name, str, len))
+ goto next;
+
+ if (d_unhashed(expiring)) {
+ dget_dlock(expiring);
+ spin_unlock(&expiring->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+ return expiring;
+ }
+next:
+ spin_unlock(&expiring->d_lock);
+ }
+ spin_unlock(&sbi->lookup_lock);
+
+ return NULL;
+}
+
+static int autofs4_mount_wait(struct dentry *dentry, bool rcu_walk)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ int status = 0;
+
+ if (ino->flags & AUTOFS_INF_PENDING) {
+ if (rcu_walk)
+ return -ECHILD;
+ DPRINTK("waiting for mount name=%pd", dentry);
+ status = autofs4_wait(sbi, dentry, NFY_MOUNT);
+ DPRINTK("mount wait done status=%d", status);
+ }
+ ino->last_used = jiffies;
+ return status;
+}
+
+static int do_expire_wait(struct dentry *dentry, bool rcu_walk)
+{
+ struct dentry *expiring;
+
+ expiring = autofs4_lookup_expiring(dentry, rcu_walk);
+ if (IS_ERR(expiring))
+ return PTR_ERR(expiring);
+ if (!expiring)
+ return autofs4_expire_wait(dentry, rcu_walk);
+ else {
+ /*
+ * If we are racing with expire the request might not
+ * be quite complete, but the directory has been removed
+ * so it must have been successful, just wait for it.
+ */
+ autofs4_expire_wait(expiring, 0);
+ autofs4_del_expiring(expiring);
+ dput(expiring);
+ }
+ return 0;
+}
+
+static struct dentry *autofs4_mountpoint_changed(struct path *path)
+{
+ struct dentry *dentry = path->dentry;
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+
+ /*
+ * If this is an indirect mount the dentry could have gone away
+ * as a result of an expire and a new one created.
+ */
+ if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) {
+ struct dentry *parent = dentry->d_parent;
+ struct autofs_info *ino;
+ struct dentry *new = d_lookup(parent, &dentry->d_name);
+ if (!new)
+ return NULL;
+ ino = autofs4_dentry_ino(new);
+ ino->last_used = jiffies;
+ dput(path->dentry);
+ path->dentry = new;
+ }
+ return path->dentry;
+}
+
+static struct vfsmount *autofs4_d_automount(struct path *path)
+{
+ struct dentry *dentry = path->dentry;
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ int status;
+
+ DPRINTK("dentry=%p %pd", dentry, dentry);
+
+ /* The daemon never triggers a mount. */
+ if (autofs4_oz_mode(sbi))
+ return NULL;
+
+ /*
+ * If an expire request is pending everyone must wait.
+ * If the expire fails we're still mounted so continue
+ * the follow and return. A return of -EAGAIN (which only
+ * happens with indirect mounts) means the expire completed
+ * and the directory was removed, so just go ahead and try
+ * the mount.
+ */
+ status = do_expire_wait(dentry, 0);
+ if (status && status != -EAGAIN)
+ return NULL;
+
+ /* Callback to the daemon to perform the mount or wait */
+ spin_lock(&sbi->fs_lock);
+ if (ino->flags & AUTOFS_INF_PENDING) {
+ spin_unlock(&sbi->fs_lock);
+ status = autofs4_mount_wait(dentry, 0);
+ if (status)
+ return ERR_PTR(status);
+ goto done;
+ }
+
+ /*
+ * If the dentry is a symlink it's equivalent to a directory
+ * having d_mountpoint() true, so there's no need to call back
+ * to the daemon.
+ */
+ if (d_really_is_positive(dentry) && d_is_symlink(dentry)) {
+ spin_unlock(&sbi->fs_lock);
+ goto done;
+ }
+
+ if (!d_mountpoint(dentry)) {
+ /*
+ * It's possible that user space hasn't removed directories
+ * after umounting a rootless multi-mount, although it
+ * should. For v5 have_submounts() is sufficient to handle
+ * this because the leaves of the directory tree under the
+ * mount never trigger mounts themselves (they have an autofs
+ * trigger mount mounted on them). But v4 pseudo direct mounts
+ * do need the leaves to trigger mounts. In this case we
+ * have no choice but to use the list_empty() check and
+ * require user space behave.
+ */
+ if (sbi->version > 4) {
+ if (have_submounts(dentry)) {
+ spin_unlock(&sbi->fs_lock);
+ goto done;
+ }
+ } else {
+ if (!simple_empty(dentry)) {
+ spin_unlock(&sbi->fs_lock);
+ goto done;
+ }
+ }
+ ino->flags |= AUTOFS_INF_PENDING;
+ spin_unlock(&sbi->fs_lock);
+ status = autofs4_mount_wait(dentry, 0);
+ spin_lock(&sbi->fs_lock);
+ ino->flags &= ~AUTOFS_INF_PENDING;
+ if (status) {
+ spin_unlock(&sbi->fs_lock);
+ return ERR_PTR(status);
+ }
+ }
+ spin_unlock(&sbi->fs_lock);
+done:
+ /* Mount succeeded, check if we ended up with a new dentry */
+ dentry = autofs4_mountpoint_changed(path);
+ if (!dentry)
+ return ERR_PTR(-ENOENT);
+
+ return NULL;
+}
+
+static int autofs4_d_manage(struct dentry *dentry, bool rcu_walk)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ int status;
+
+ DPRINTK("dentry=%p %pd", dentry, dentry);
+
+ /* The daemon never waits. */
+ if (autofs4_oz_mode(sbi)) {
+ if (!d_mountpoint(dentry))
+ return -EISDIR;
+ return 0;
+ }
+
+ /* Wait for pending expires */
+ if (do_expire_wait(dentry, rcu_walk) == -ECHILD)
+ return -ECHILD;
+
+ /*
+ * This dentry may be under construction so wait on mount
+ * completion.
+ */
+ status = autofs4_mount_wait(dentry, rcu_walk);
+ if (status)
+ return status;
+
+ if (rcu_walk) {
+ /* We don't need fs_lock in rcu_walk mode,
+ * just testing 'AUTOFS_INFO_NO_RCU' is enough.
+ * simple_empty() takes a spinlock, so leave it
+ * to last.
+ * We only return -EISDIR when certain this isn't
+ * a mount-trap.
+ */
+ struct inode *inode;
+ if (ino->flags & (AUTOFS_INF_EXPIRING | AUTOFS_INF_NO_RCU))
+ return 0;
+ if (d_mountpoint(dentry))
+ return 0;
+ inode = d_inode_rcu(dentry);
+ if (inode && S_ISLNK(inode->i_mode))
+ return -EISDIR;
+ if (list_empty(&dentry->d_subdirs))
+ return 0;
+ if (!simple_empty(dentry))
+ return -EISDIR;
+ return 0;
+ }
+
+ spin_lock(&sbi->fs_lock);
+ /*
+ * If the dentry has been selected for expire while we slept
+ * on the lock then it might go away. We'll deal with that in
+ * ->d_automount() and wait on a new mount if the expire
+ * succeeds or return here if it doesn't (since there's no
+ * mount to follow with a rootless multi-mount).
+ */
+ if (!(ino->flags & AUTOFS_INF_EXPIRING)) {
+ /*
+ * Any needed mounting has been completed and the path
+ * updated so check if this is a rootless multi-mount so
+ * we can avoid needless calls ->d_automount() and avoid
+ * an incorrect ELOOP error return.
+ */
+ if ((!d_mountpoint(dentry) && !simple_empty(dentry)) ||
+ (d_really_is_positive(dentry) && d_is_symlink(dentry)))
+ status = -EISDIR;
+ }
+ spin_unlock(&sbi->fs_lock);
+
+ return status;
+}
+
+/* Lookups in the root directory */
+static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+ struct autofs_sb_info *sbi;
+ struct autofs_info *ino;
+ struct dentry *active;
+
+ DPRINTK("name = %pd", dentry);
+
+ /* File name too long to exist */
+ if (dentry->d_name.len > NAME_MAX)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ sbi = autofs4_sbi(dir->i_sb);
+
+ DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
+ current->pid, task_pgrp_nr(current), sbi->catatonic,
+ autofs4_oz_mode(sbi));
+
+ active = autofs4_lookup_active(dentry);
+ if (active) {
+ return active;
+ } else {
+ /*
+ * A dentry that is not within the root can never trigger a
+ * mount operation, unless the directory already exists, so we
+ * can return fail immediately. The daemon however does need
+ * to create directories within the file system.
+ */
+ if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent))
+ return ERR_PTR(-ENOENT);
+
+ /* Mark entries in the root as mount triggers */
+ if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent))
+ __managed_dentry_set_managed(dentry);
+
+ ino = autofs4_new_ino(sbi);
+ if (!ino)
+ return ERR_PTR(-ENOMEM);
+
+ dentry->d_fsdata = ino;
+ ino->dentry = dentry;
+
+ autofs4_add_active(dentry);
+
+ d_instantiate(dentry, NULL);
+ }
+ 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 autofs_info *p_ino;
+ struct inode *inode;
+ size_t size = strlen(symname);
+ char *cp;
+
+ DPRINTK("%s <- %pd", symname, dentry);
+
+ if (!autofs4_oz_mode(sbi))
+ return -EACCES;
+
+ BUG_ON(!ino);
+
+ autofs4_clean_ino(ino);
+
+ autofs4_del_active(dentry);
+
+ cp = kmalloc(size + 1, GFP_KERNEL);
+ if (!cp)
+ return -ENOMEM;
+
+ strcpy(cp, symname);
+
+ inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555);
+ if (!inode) {
+ kfree(cp);
+ if (!dentry->d_fsdata)
+ kfree(ino);
+ return -ENOMEM;
+ }
+ inode->i_private = cp;
+ inode->i_size = size;
+ d_add(dentry, inode);
+
+ dget(dentry);
+ atomic_inc(&ino->count);
+ p_ino = autofs4_dentry_ino(dentry->d_parent);
+ if (p_ino && !IS_ROOT(dentry))
+ atomic_inc(&p_ino->count);
+
+ 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 the unlink is probably the result of an expire.
+ * We simply d_drop it and add it to a expiring list in the super block,
+ * which allows the dentry lookup to check for an incomplete expire.
+ *
+ * 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);
+ struct autofs_info *p_ino;
+
+ /* This allows root to remove symlinks */
+ if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (atomic_dec_and_test(&ino->count)) {
+ p_ino = autofs4_dentry_ino(dentry->d_parent);
+ if (p_ino && !IS_ROOT(dentry))
+ atomic_dec(&p_ino->count);
+ }
+ dput(ino->dentry);
+
+ d_inode(dentry)->i_size = 0;
+ clear_nlink(d_inode(dentry));
+
+ dir->i_mtime = CURRENT_TIME;
+
+ spin_lock(&sbi->lookup_lock);
+ __autofs4_add_expiring(dentry);
+ d_drop(dentry);
+ spin_unlock(&sbi->lookup_lock);
+
+ return 0;
+}
+
+/*
+ * Version 4 of autofs provides a pseudo direct mount implementation
+ * that relies on directories at the leaves of a directory tree under
+ * an indirect mount to trigger mounts. To allow for this we need to
+ * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves
+ * of the directory tree. There is no need to clear the automount flag
+ * following a mount or restore it after an expire because these mounts
+ * are always covered. However, it is necessary to ensure that these
+ * flags are clear on non-empty directories to avoid unnecessary calls
+ * during path walks.
+ */
+static void autofs_set_leaf_automount_flags(struct dentry *dentry)
+{
+ struct dentry *parent;
+
+ /* root and dentrys in the root are already handled */
+ if (IS_ROOT(dentry->d_parent))
+ return;
+
+ managed_dentry_set_managed(dentry);
+
+ parent = dentry->d_parent;
+ /* only consider parents below dentrys in the root */
+ if (IS_ROOT(parent->d_parent))
+ return;
+ managed_dentry_clear_managed(parent);
+ return;
+}
+
+static void autofs_clear_leaf_automount_flags(struct dentry *dentry)
+{
+ struct list_head *d_child;
+ struct dentry *parent;
+
+ /* flags for dentrys in the root are handled elsewhere */
+ if (IS_ROOT(dentry->d_parent))
+ return;
+
+ managed_dentry_clear_managed(dentry);
+
+ parent = dentry->d_parent;
+ /* only consider parents below dentrys in the root */
+ if (IS_ROOT(parent->d_parent))
+ return;
+ d_child = &dentry->d_child;
+ /* Set parent managed if it's becoming empty */
+ if (d_child->next == &parent->d_subdirs &&
+ d_child->prev == &parent->d_subdirs)
+ managed_dentry_set_managed(parent);
+ return;
+}
+
+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);
+ struct autofs_info *p_ino;
+
+ DPRINTK("dentry %p, removing %pd", dentry, dentry);
+
+ if (!autofs4_oz_mode(sbi))
+ return -EACCES;
+
+ spin_lock(&sbi->lookup_lock);
+ if (!simple_empty(dentry)) {
+ spin_unlock(&sbi->lookup_lock);
+ return -ENOTEMPTY;
+ }
+ __autofs4_add_expiring(dentry);
+ d_drop(dentry);
+ spin_unlock(&sbi->lookup_lock);
+
+ if (sbi->version < 5)
+ autofs_clear_leaf_automount_flags(dentry);
+
+ if (atomic_dec_and_test(&ino->count)) {
+ p_ino = autofs4_dentry_ino(dentry->d_parent);
+ if (p_ino && dentry->d_parent != dentry)
+ atomic_dec(&p_ino->count);
+ }
+ dput(ino->dentry);
+ d_inode(dentry)->i_size = 0;
+ clear_nlink(d_inode(dentry));
+
+ if (dir->i_nlink)
+ drop_nlink(dir);
+
+ return 0;
+}
+
+static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ struct autofs_info *p_ino;
+ struct inode *inode;
+
+ if (!autofs4_oz_mode(sbi))
+ return -EACCES;
+
+ DPRINTK("dentry %p, creating %pd", dentry, dentry);
+
+ BUG_ON(!ino);
+
+ autofs4_clean_ino(ino);
+
+ autofs4_del_active(dentry);
+
+ inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555);
+ if (!inode)
+ return -ENOMEM;
+ d_add(dentry, inode);
+
+ if (sbi->version < 5)
+ autofs_set_leaf_automount_flags(dentry);
+
+ dget(dentry);
+ atomic_inc(&ino->count);
+ p_ino = autofs4_dentry_ino(dentry->d_parent);
+ if (p_ino && !IS_ROOT(dentry))
+ atomic_inc(&p_ino->count);
+ inc_nlink(dir);
+ dir->i_mtime = CURRENT_TIME;
+
+ return 0;
+}
+
+/* Get/set timeout ioctl() operation */
+#ifdef CONFIG_COMPAT
+static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi,
+ compat_ulong_t __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 > UINT_MAX/HZ)
+ sbi->exp_timeout = 0;
+ else
+ sbi->exp_timeout = ntimeout * HZ;
+
+ return 0;
+}
+#endif
+
+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 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))
+ 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 && d_really_is_positive(dentry) &&
+ 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_unlocked(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,task_pgrp_nr(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);
+#ifdef CONFIG_COMPAT
+ case AUTOFS_IOC_SETTIMEOUT32:
+ return autofs4_compat_get_set_timeout(sbi, p);
+#endif
+
+ case AUTOFS_IOC_ASKUMOUNT:
+ return autofs4_ask_umount(filp->f_path.mnt, p);
+
+ /* return a single thing to expire */
+ case AUTOFS_IOC_EXPIRE:
+ return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,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_path.mnt,sbi, p);
+
+ default:
+ return -ENOSYS;
+ }
+}
+
+static long autofs4_root_ioctl(struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+ return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
+}
+
+#ifdef CONFIG_COMPAT
+static long autofs4_root_compat_ioctl(struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+ int ret;
+
+ if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL)
+ ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
+ else
+ ret = autofs4_root_ioctl_unlocked(inode, filp, cmd,
+ (unsigned long)compat_ptr(arg));
+
+ return ret;
+}
+#endif
Code Review / kvmfornfv.git / blobdiff