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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
  * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
  * Copyright 2001-2006 Ian Kent <raven@themaw.net>
  */
 
 #include <linux/capability.h>
 #include <linux/compat.h>
 
 #include "autofs_i.h"
 
 static int autofs_dir_permission(struct user_namespace *, struct inode *, int);
 static int autofs_dir_symlink(struct user_namespace *, struct inode *,
                   struct dentry *, const char *);
 static int autofs_dir_unlink(struct inode *, struct dentry *);
 static int autofs_dir_rmdir(struct inode *, struct dentry *);
 static int autofs_dir_mkdir(struct user_namespace *, struct inode *,
                 struct dentry *, umode_t);
 static long autofs_root_ioctl(struct file *, unsigned int, unsigned long);
 #ifdef CONFIG_COMPAT
 static long autofs_root_compat_ioctl(struct file *,
                      unsigned int, unsigned long);
 #endif
 static int autofs_dir_open(struct inode *inode, struct file *file);
 static struct dentry *autofs_lookup(struct inode *,
                     struct dentry *, unsigned int);
 static struct vfsmount *autofs_d_automount(struct path *);
 static int autofs_d_manage(const struct path *, bool);
 static void autofs_dentry_release(struct dentry *);
 
 const struct file_operations autofs_root_operations = {
     .open       = dcache_dir_open,
     .release    = dcache_dir_close,
     .read       = generic_read_dir,
     .iterate_shared = dcache_readdir,
     .llseek     = dcache_dir_lseek,
     .unlocked_ioctl = autofs_root_ioctl,
 #ifdef CONFIG_COMPAT
     .compat_ioctl   = autofs_root_compat_ioctl,
 #endif
 };
 
 const struct file_operations autofs_dir_operations = {
     .open       = autofs_dir_open,
     .release    = dcache_dir_close,
     .read       = generic_read_dir,
     .iterate_shared = dcache_readdir,
     .llseek     = dcache_dir_lseek,
 };
 
 const struct inode_operations autofs_dir_inode_operations = {
     .lookup     = autofs_lookup,
     .permission = autofs_dir_permission,
     .unlink     = autofs_dir_unlink,
     .symlink    = autofs_dir_symlink,
     .mkdir      = autofs_dir_mkdir,
     .rmdir      = autofs_dir_rmdir,
 };
 
 const struct dentry_operations autofs_dentry_operations = {
     .d_automount    = autofs_d_automount,
     .d_manage   = autofs_d_manage,
     .d_release  = autofs_dentry_release,
 };
 
 static void autofs_del_active(struct dentry *dentry)
 {
     struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
     struct autofs_info *ino;
 
     ino = autofs_dentry_ino(dentry);
     spin_lock(&sbi->lookup_lock);
     list_del_init(&ino->active);
     spin_unlock(&sbi->lookup_lock);
 }
 
 static int autofs_dir_open(struct inode *inode, struct file *file)
 {
     struct dentry *dentry = file->f_path.dentry;
     struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
     struct autofs_info *ino = autofs_dentry_ino(dentry);
 
     pr_debug("file=%p dentry=%p %pd\n", file, dentry, dentry);
 
     if (autofs_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 (!path_is_mountpoint(&file->f_path) && autofs_empty(ino)) {
         spin_unlock(&sbi->lookup_lock);
         return -ENOENT;
     }
     spin_unlock(&sbi->lookup_lock);
 
 out:
     return dcache_dir_open(inode, file);
 }
 
 static void autofs_dentry_release(struct dentry *de)
 {
     struct autofs_info *ino = autofs_dentry_ino(de);
     struct autofs_sb_info *sbi = autofs_sbi(de->d_sb);
 
     pr_debug("releasing %p\n", 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);
     }
 
     autofs_free_ino(ino);
 }
 
 static struct dentry *autofs_lookup_active(struct dentry *dentry)
 {
     struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
     struct dentry *parent = dentry->d_parent;
     const 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;
         const 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 *autofs_lookup_expiring(struct dentry *dentry,
                          bool rcu_walk)
 {
     struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
     struct dentry *parent = dentry->d_parent;
     const 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;
         const 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 autofs_mount_wait(const struct path *path, bool rcu_walk)
 {
     struct autofs_sb_info *sbi = autofs_sbi(path->dentry->d_sb);
     struct autofs_info *ino = autofs_dentry_ino(path->dentry);
     int status = 0;
 
     if (ino->flags & AUTOFS_INF_PENDING) {
         if (rcu_walk)
             return -ECHILD;
         pr_debug("waiting for mount name=%pd\n", path->dentry);
         status = autofs_wait(sbi, path, NFY_MOUNT);
         pr_debug("mount wait done status=%d\n", status);
         ino->last_used = jiffies;
         return status;
     }
     if (!(sbi->flags & AUTOFS_SBI_STRICTEXPIRE))
         ino->last_used = jiffies;
     return status;
 }
 
 static int do_expire_wait(const struct path *path, bool rcu_walk)
 {
     struct dentry *dentry = path->dentry;
     struct dentry *expiring;
 
     expiring = autofs_lookup_expiring(dentry, rcu_walk);
     if (IS_ERR(expiring))
         return PTR_ERR(expiring);
     if (!expiring)
         return autofs_expire_wait(path, rcu_walk);
     else {
         const struct path this = { .mnt = path->mnt, .dentry = expiring };
         /*
          * 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.
          */
         autofs_expire_wait(&this, 0);
         autofs_del_expiring(expiring);
         dput(expiring);
     }
     return 0;
 }
 
 static struct dentry *autofs_mountpoint_changed(struct path *path)
 {
     struct dentry *dentry = path->dentry;
     struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
 
     /* If this is an indirect mount the dentry could have gone away
      * and a new one created.
      *
      * This is unusual and I can't remember the case for which it
      * was originally added now. But an example of how this can
      * happen is an autofs indirect mount that has the "browse"
      * option set and also has the "symlink" option in the autofs
      * map entry. In this case the daemon will remove the browse
      * directory and create a symlink as the mount leaving the
      * struct path stale.
      *
      * Another not so obvious case is when a mount in an autofs
      * indirect mount that uses the "nobrowse" option is being
      * expired at the same time as a path walk. If the mount has
      * been umounted but the mount point directory seen before
      * becoming unhashed (during a lockless path walk) when a stat
      * family system call is made the mount won't be re-mounted as
      * it should. In this case the mount point that's been removed
      * (by the daemon) will be stale and the a new mount point
      * dentry created.
      */
     if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) {
         struct dentry *parent = dentry->d_parent;
         struct autofs_info *ino;
         struct dentry *new;
 
         new = d_lookup(parent, &dentry->d_name);
         if (!new)
             return NULL;
         ino = autofs_dentry_ino(new);
         ino->last_used = jiffies;
         dput(path->dentry);
         path->dentry = new;
     }
     return path->dentry;
 }
 
 static struct vfsmount *autofs_d_automount(struct path *path)
 {
     struct dentry *dentry = path->dentry;
     struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
     struct autofs_info *ino = autofs_dentry_ino(dentry);
     int status;
 
     pr_debug("dentry=%p %pd\n", dentry, dentry);
 
     /* The daemon never triggers a mount. */
     if (autofs_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(path, 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 = autofs_mount_wait(path, 0);
         if (status)
             return ERR_PTR(status);
         goto done;
     }
 
     /*
      * If the dentry is a symlink it's equivalent to a directory
      * having path_is_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 (!path_is_mountpoint(path)) {
         /*
          * It's possible that user space hasn't removed directories
          * after umounting a rootless multi-mount, although it
          * should. For v5 path_has_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 autofs_empty() check and
          * require user space behave.
          */
         if (sbi->version > 4) {
             if (path_has_submounts(path)) {
                 spin_unlock(&sbi->fs_lock);
                 goto done;
             }
         } else {
             if (!autofs_empty(ino)) {
                 spin_unlock(&sbi->fs_lock);
                 goto done;
             }
         }
         ino->flags |= AUTOFS_INF_PENDING;
         spin_unlock(&sbi->fs_lock);
         status = autofs_mount_wait(path, 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 = autofs_mountpoint_changed(path);
     if (!dentry)
         return ERR_PTR(-ENOENT);
 
     return NULL;
 }
 
 static int autofs_d_manage(const struct path *path, bool rcu_walk)
 {
     struct dentry *dentry = path->dentry;
     struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
     struct autofs_info *ino = autofs_dentry_ino(dentry);
     int status;
 
     pr_debug("dentry=%p %pd\n", dentry, dentry);
 
     /* The daemon never waits. */
     if (autofs_oz_mode(sbi)) {
         if (!path_is_mountpoint(path))
             return -EISDIR;
         return 0;
     }
 
     /* Wait for pending expires */
     if (do_expire_wait(path, rcu_walk) == -ECHILD)
         return -ECHILD;
 
     /*
      * This dentry may be under construction so wait on mount
      * completion.
      */
     status = autofs_mount_wait(path, rcu_walk);
     if (status)
         return status;
 
     if (rcu_walk) {
         /* We don't need fs_lock in rcu_walk mode,
          * just testing 'AUTOFS_INF_WANT_EXPIRE' is enough.
          *
          * We only return -EISDIR when certain this isn't
          * a mount-trap.
          */
         struct inode *inode;
 
         if (ino->flags & AUTOFS_INF_WANT_EXPIRE)
             return 0;
         if (path_is_mountpoint(path))
             return 0;
         inode = d_inode_rcu(dentry);
         if (inode && S_ISLNK(inode->i_mode))
             return -EISDIR;
         if (!autofs_empty(ino))
             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 ((!path_is_mountpoint(path) && !autofs_empty(ino)) ||
             (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 *autofs_lookup(struct inode *dir,
                     struct dentry *dentry, unsigned int flags)
 {
     struct autofs_sb_info *sbi;
     struct autofs_info *ino;
     struct dentry *active;
 
     pr_debug("name = %pd\n", dentry);
 
     /* File name too long to exist */
     if (dentry->d_name.len > NAME_MAX)
         return ERR_PTR(-ENAMETOOLONG);
 
     sbi = autofs_sbi(dir->i_sb);
 
     pr_debug("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
          current->pid, task_pgrp_nr(current),
          sbi->flags & AUTOFS_SBI_CATATONIC,
          autofs_oz_mode(sbi));
 
     active = autofs_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 (!autofs_oz_mode(sbi) && !IS_ROOT(dentry->d_parent))
             return ERR_PTR(-ENOENT);
 
         ino = autofs_new_ino(sbi);
         if (!ino)
             return ERR_PTR(-ENOMEM);
 
         spin_lock(&sbi->lookup_lock);
         spin_lock(&dentry->d_lock);
         /* Mark entries in the root as mount triggers */
         if (IS_ROOT(dentry->d_parent) &&
             autofs_type_indirect(sbi->type))
             __managed_dentry_set_managed(dentry);
         dentry->d_fsdata = ino;
         ino->dentry = dentry;
 
         list_add(&ino->active, &sbi->active_list);
         spin_unlock(&sbi->lookup_lock);
         spin_unlock(&dentry->d_lock);
     }
     return NULL;
 }
 
 static int autofs_dir_permission(struct user_namespace *mnt_userns,
                  struct inode *inode, int mask)
 {
     if (mask & MAY_WRITE) {
         struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
 
         if (!autofs_oz_mode(sbi))
             return -EACCES;
 
         /* autofs_oz_mode() needs to allow path walks when the
          * autofs mount is catatonic but the state of an autofs
          * file system needs to be preserved over restarts.
          */
         if (sbi->flags & AUTOFS_SBI_CATATONIC)
             return -EACCES;
     }
 
     return generic_permission(mnt_userns, inode, mask);
 }
 
 static int autofs_dir_symlink(struct user_namespace *mnt_userns,
                   struct inode *dir, struct dentry *dentry,
                   const char *symname)
 {
     struct autofs_info *ino = autofs_dentry_ino(dentry);
     struct autofs_info *p_ino;
     struct inode *inode;
     size_t size = strlen(symname);
     char *cp;
 
     pr_debug("%s <- %pd\n", symname, dentry);
 
     BUG_ON(!ino);
 
     autofs_clean_ino(ino);
 
     autofs_del_active(dentry);
 
     cp = kmalloc(size + 1, GFP_KERNEL);
     if (!cp)
         return -ENOMEM;
 
     strcpy(cp, symname);
 
     inode = autofs_get_inode(dir->i_sb, S_IFLNK | 0555);
     if (!inode) {
         kfree(cp);
         return -ENOMEM;
     }
     inode->i_private = cp;
     inode->i_size = size;
     d_add(dentry, inode);
 
     dget(dentry);
     p_ino = autofs_dentry_ino(dentry->d_parent);
     p_ino->count++;
 
     dir->i_mtime = current_time(dir);
 
     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 autofs_dir_rmdir()..
  */
 static int autofs_dir_unlink(struct inode *dir, struct dentry *dentry)
 {
     struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
     struct autofs_info *ino = autofs_dentry_ino(dentry);
     struct autofs_info *p_ino;
 
     p_ino = autofs_dentry_ino(dentry->d_parent);
     p_ino->count--;
     dput(ino->dentry);
 
     d_inode(dentry)->i_size = 0;
     clear_nlink(d_inode(dentry));
 
     dir->i_mtime = current_time(dir);
 
     spin_lock(&sbi->lookup_lock);
     __autofs_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);
 }
 
 static void autofs_clear_leaf_automount_flags(struct dentry *dentry)
 {
     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;
     if (autofs_dentry_ino(parent)->count == 2)
         managed_dentry_set_managed(parent);
 }
 
 static int autofs_dir_rmdir(struct inode *dir, struct dentry *dentry)
 {
     struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
     struct autofs_info *ino = autofs_dentry_ino(dentry);
     struct autofs_info *p_ino;
 
     pr_debug("dentry %p, removing %pd\n", dentry, dentry);
 
     if (ino->count != 1)
         return -ENOTEMPTY;
 
     spin_lock(&sbi->lookup_lock);
     __autofs_add_expiring(dentry);
     d_drop(dentry);
     spin_unlock(&sbi->lookup_lock);
 
     if (sbi->version < 5)
         autofs_clear_leaf_automount_flags(dentry);
 
     p_ino = autofs_dentry_ino(dentry->d_parent);
     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 autofs_dir_mkdir(struct user_namespace *mnt_userns,
                 struct inode *dir, struct dentry *dentry,
                 umode_t mode)
 {
     struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
     struct autofs_info *ino = autofs_dentry_ino(dentry);
     struct autofs_info *p_ino;
     struct inode *inode;
 
     pr_debug("dentry %p, creating %pd\n", dentry, dentry);
 
     BUG_ON(!ino);
 
     autofs_clean_ino(ino);
 
     autofs_del_active(dentry);
 
     inode = autofs_get_inode(dir->i_sb, S_IFDIR | mode);
     if (!inode)
         return -ENOMEM;
     d_add(dentry, inode);
 
     if (sbi->version < 5)
         autofs_set_leaf_automount_flags(dentry);
 
     dget(dentry);
     p_ino = autofs_dentry_ino(dentry->d_parent);
     p_ino->count++;
     inc_nlink(dir);
     dir->i_mtime = current_time(dir);
 
     return 0;
 }
 
 /* Get/set timeout ioctl() operation */
 #ifdef CONFIG_COMPAT
 static inline int autofs_compat_get_set_timeout(struct autofs_sb_info *sbi,
                          compat_ulong_t __user *p)
 {
     unsigned long ntimeout;
     int rv;
 
     rv = get_user(ntimeout, p);
     if (rv)
         goto error;
 
     rv = put_user(sbi->exp_timeout/HZ, p);
     if (rv)
         goto error;
 
     if (ntimeout > UINT_MAX/HZ)
         sbi->exp_timeout = 0;
     else
         sbi->exp_timeout = ntimeout * HZ;
 
     return 0;
 error:
     return rv;
 }
 #endif
 
 static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi,
                       unsigned long __user *p)
 {
     unsigned long ntimeout;
     int rv;
 
     rv = get_user(ntimeout, p);
     if (rv)
         goto error;
 
     rv = put_user(sbi->exp_timeout/HZ, p);
     if (rv)
         goto error;
 
     if (ntimeout > ULONG_MAX/HZ)
         sbi->exp_timeout = 0;
     else
         sbi->exp_timeout = ntimeout * HZ;
 
     return 0;
 error:
     return rv;
 }
 
 /* Return protocol version */
 static inline int autofs_get_protover(struct autofs_sb_info *sbi,
                        int __user *p)
 {
     return put_user(sbi->version, p);
 }
 
 /* Return protocol sub version */
 static inline int autofs_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 autofs_ask_umount(struct vfsmount *mnt, int __user *p)
 {
     int status = 0;
 
     if (may_umount(mnt))
         status = 1;
 
     pr_debug("may umount %d\n", status);
 
     status = put_user(status, p);
 
     return status;
 }
 
 /* Identify autofs_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_autofs_dentry(struct dentry *dentry)
 {
     return dentry && d_really_is_positive(dentry) &&
         dentry->d_op == &autofs_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 autofs_root_ioctl_unlocked(struct inode *inode, struct file *filp,
                        unsigned int cmd, unsigned long arg)
 {
     struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
     void __user *p = (void __user *)arg;
 
     pr_debug("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",
          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 (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
         return -EPERM;
 
     switch (cmd) {
     case AUTOFS_IOC_READY:  /* Wait queue: go ahead and retry */
         return autofs_wait_release(sbi, (autofs_wqt_t) arg, 0);
     case AUTOFS_IOC_FAIL:   /* Wait queue: fail with ENOENT */
         return autofs_wait_release(sbi, (autofs_wqt_t) arg, -ENOENT);
     case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
         autofs_catatonic_mode(sbi);
         return 0;
     case AUTOFS_IOC_PROTOVER: /* Get protocol version */
         return autofs_get_protover(sbi, p);
     case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
         return autofs_get_protosubver(sbi, p);
     case AUTOFS_IOC_SETTIMEOUT:
         return autofs_get_set_timeout(sbi, p);
 #ifdef CONFIG_COMPAT
     case AUTOFS_IOC_SETTIMEOUT32:
         return autofs_compat_get_set_timeout(sbi, p);
 #endif
 
     case AUTOFS_IOC_ASKUMOUNT:
         return autofs_ask_umount(filp->f_path.mnt, p);
 
     /* return a single thing to expire */
     case AUTOFS_IOC_EXPIRE:
         return autofs_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 autofs_expire_multi(inode->i_sb,
                        filp->f_path.mnt, sbi, p);
 
     default:
         return -EINVAL;
     }
 }
 
 static long autofs_root_ioctl(struct file *filp,
                    unsigned int cmd, unsigned long arg)
 {
     struct inode *inode = file_inode(filp);
 
     return autofs_root_ioctl_unlocked(inode, filp, cmd, arg);
 }
 
 #ifdef CONFIG_COMPAT
 static long autofs_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 = autofs_root_ioctl_unlocked(inode, filp, cmd, arg);
     else
         ret = autofs_root_ioctl_unlocked(inode, filp, cmd,
                           (unsigned long) compat_ptr(arg));
 
     return ret;
 }
 #endif

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