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The function autofs_mountpoint_changed() is unusual, add a comment about two cases for which it is needed. Link: https://lkml.kernel.org/r/165724459804.30914.10974834416046555127.stgit@donald.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
929 lines
24 KiB
C
929 lines
24 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
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* Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
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* Copyright 2001-2006 Ian Kent <raven@themaw.net>
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*/
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#include <linux/capability.h>
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#include <linux/compat.h>
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#include "autofs_i.h"
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static int autofs_dir_permission(struct user_namespace *, struct inode *, int);
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static int autofs_dir_symlink(struct user_namespace *, struct inode *,
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struct dentry *, const char *);
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static int autofs_dir_unlink(struct inode *, struct dentry *);
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static int autofs_dir_rmdir(struct inode *, struct dentry *);
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static int autofs_dir_mkdir(struct user_namespace *, struct inode *,
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struct dentry *, umode_t);
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static long autofs_root_ioctl(struct file *, unsigned int, unsigned long);
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#ifdef CONFIG_COMPAT
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static long autofs_root_compat_ioctl(struct file *,
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unsigned int, unsigned long);
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#endif
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static int autofs_dir_open(struct inode *inode, struct file *file);
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static struct dentry *autofs_lookup(struct inode *,
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struct dentry *, unsigned int);
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static struct vfsmount *autofs_d_automount(struct path *);
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static int autofs_d_manage(const struct path *, bool);
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static void autofs_dentry_release(struct dentry *);
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const struct file_operations autofs_root_operations = {
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.open = dcache_dir_open,
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.release = dcache_dir_close,
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.read = generic_read_dir,
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.iterate_shared = dcache_readdir,
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.llseek = dcache_dir_lseek,
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.unlocked_ioctl = autofs_root_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = autofs_root_compat_ioctl,
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#endif
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};
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const struct file_operations autofs_dir_operations = {
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.open = autofs_dir_open,
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.release = dcache_dir_close,
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.read = generic_read_dir,
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.iterate_shared = dcache_readdir,
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.llseek = dcache_dir_lseek,
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};
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const struct inode_operations autofs_dir_inode_operations = {
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.lookup = autofs_lookup,
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.permission = autofs_dir_permission,
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.unlink = autofs_dir_unlink,
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.symlink = autofs_dir_symlink,
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.mkdir = autofs_dir_mkdir,
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.rmdir = autofs_dir_rmdir,
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};
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const struct dentry_operations autofs_dentry_operations = {
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.d_automount = autofs_d_automount,
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.d_manage = autofs_d_manage,
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.d_release = autofs_dentry_release,
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};
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static void autofs_del_active(struct dentry *dentry)
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{
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struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
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struct autofs_info *ino;
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ino = autofs_dentry_ino(dentry);
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spin_lock(&sbi->lookup_lock);
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list_del_init(&ino->active);
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spin_unlock(&sbi->lookup_lock);
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}
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static int autofs_dir_open(struct inode *inode, struct file *file)
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{
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struct dentry *dentry = file->f_path.dentry;
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struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
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struct autofs_info *ino = autofs_dentry_ino(dentry);
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pr_debug("file=%p dentry=%p %pd\n", file, dentry, dentry);
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if (autofs_oz_mode(sbi))
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goto out;
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/*
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* An empty directory in an autofs file system is always a
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* mount point. The daemon must have failed to mount this
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* during lookup so it doesn't exist. This can happen, for
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* example, if user space returns an incorrect status for a
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* mount request. Otherwise we're doing a readdir on the
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* autofs file system so just let the libfs routines handle
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* it.
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*/
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spin_lock(&sbi->lookup_lock);
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if (!path_is_mountpoint(&file->f_path) && autofs_empty(ino)) {
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spin_unlock(&sbi->lookup_lock);
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return -ENOENT;
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}
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spin_unlock(&sbi->lookup_lock);
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out:
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return dcache_dir_open(inode, file);
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}
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static void autofs_dentry_release(struct dentry *de)
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{
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struct autofs_info *ino = autofs_dentry_ino(de);
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struct autofs_sb_info *sbi = autofs_sbi(de->d_sb);
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pr_debug("releasing %p\n", de);
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if (!ino)
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return;
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if (sbi) {
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spin_lock(&sbi->lookup_lock);
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if (!list_empty(&ino->active))
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list_del(&ino->active);
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if (!list_empty(&ino->expiring))
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list_del(&ino->expiring);
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spin_unlock(&sbi->lookup_lock);
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}
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autofs_free_ino(ino);
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}
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static struct dentry *autofs_lookup_active(struct dentry *dentry)
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{
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struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
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struct dentry *parent = dentry->d_parent;
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const struct qstr *name = &dentry->d_name;
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unsigned int len = name->len;
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unsigned int hash = name->hash;
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const unsigned char *str = name->name;
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struct list_head *p, *head;
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head = &sbi->active_list;
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if (list_empty(head))
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return NULL;
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spin_lock(&sbi->lookup_lock);
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list_for_each(p, head) {
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struct autofs_info *ino;
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struct dentry *active;
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const struct qstr *qstr;
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ino = list_entry(p, struct autofs_info, active);
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active = ino->dentry;
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spin_lock(&active->d_lock);
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/* Already gone? */
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if ((int) d_count(active) <= 0)
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goto next;
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qstr = &active->d_name;
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if (active->d_name.hash != hash)
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goto next;
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if (active->d_parent != parent)
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goto next;
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if (qstr->len != len)
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goto next;
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if (memcmp(qstr->name, str, len))
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goto next;
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if (d_unhashed(active)) {
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dget_dlock(active);
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spin_unlock(&active->d_lock);
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spin_unlock(&sbi->lookup_lock);
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return active;
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}
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next:
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spin_unlock(&active->d_lock);
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}
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spin_unlock(&sbi->lookup_lock);
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return NULL;
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}
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static struct dentry *autofs_lookup_expiring(struct dentry *dentry,
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bool rcu_walk)
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{
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struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
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struct dentry *parent = dentry->d_parent;
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const struct qstr *name = &dentry->d_name;
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unsigned int len = name->len;
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unsigned int hash = name->hash;
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const unsigned char *str = name->name;
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struct list_head *p, *head;
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head = &sbi->expiring_list;
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if (list_empty(head))
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return NULL;
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spin_lock(&sbi->lookup_lock);
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list_for_each(p, head) {
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struct autofs_info *ino;
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struct dentry *expiring;
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const struct qstr *qstr;
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if (rcu_walk) {
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spin_unlock(&sbi->lookup_lock);
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return ERR_PTR(-ECHILD);
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}
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ino = list_entry(p, struct autofs_info, expiring);
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expiring = ino->dentry;
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spin_lock(&expiring->d_lock);
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/* We've already been dentry_iput or unlinked */
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if (d_really_is_negative(expiring))
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goto next;
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qstr = &expiring->d_name;
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if (expiring->d_name.hash != hash)
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goto next;
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if (expiring->d_parent != parent)
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goto next;
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if (qstr->len != len)
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goto next;
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if (memcmp(qstr->name, str, len))
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goto next;
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if (d_unhashed(expiring)) {
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dget_dlock(expiring);
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spin_unlock(&expiring->d_lock);
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spin_unlock(&sbi->lookup_lock);
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return expiring;
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}
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next:
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spin_unlock(&expiring->d_lock);
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}
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spin_unlock(&sbi->lookup_lock);
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return NULL;
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}
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static int autofs_mount_wait(const struct path *path, bool rcu_walk)
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{
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struct autofs_sb_info *sbi = autofs_sbi(path->dentry->d_sb);
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struct autofs_info *ino = autofs_dentry_ino(path->dentry);
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int status = 0;
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if (ino->flags & AUTOFS_INF_PENDING) {
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if (rcu_walk)
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return -ECHILD;
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pr_debug("waiting for mount name=%pd\n", path->dentry);
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status = autofs_wait(sbi, path, NFY_MOUNT);
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pr_debug("mount wait done status=%d\n", status);
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ino->last_used = jiffies;
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return status;
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}
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if (!(sbi->flags & AUTOFS_SBI_STRICTEXPIRE))
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ino->last_used = jiffies;
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return status;
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}
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static int do_expire_wait(const struct path *path, bool rcu_walk)
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{
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struct dentry *dentry = path->dentry;
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struct dentry *expiring;
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expiring = autofs_lookup_expiring(dentry, rcu_walk);
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if (IS_ERR(expiring))
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return PTR_ERR(expiring);
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if (!expiring)
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return autofs_expire_wait(path, rcu_walk);
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else {
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const struct path this = { .mnt = path->mnt, .dentry = expiring };
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/*
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* If we are racing with expire the request might not
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* be quite complete, but the directory has been removed
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* so it must have been successful, just wait for it.
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*/
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autofs_expire_wait(&this, 0);
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autofs_del_expiring(expiring);
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dput(expiring);
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}
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return 0;
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}
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static struct dentry *autofs_mountpoint_changed(struct path *path)
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{
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struct dentry *dentry = path->dentry;
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struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
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/* If this is an indirect mount the dentry could have gone away
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* and a new one created.
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*
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* This is unusual and I can't remember the case for which it
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* was originally added now. But an example of how this can
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* happen is an autofs indirect mount that has the "browse"
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* option set and also has the "symlink" option in the autofs
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* map entry. In this case the daemon will remove the browse
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* directory and create a symlink as the mount leaving the
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* struct path stale.
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*
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* Another not so obvious case is when a mount in an autofs
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* indirect mount that uses the "nobrowse" option is being
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* expired at the same time as a path walk. If the mount has
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* been umounted but the mount point directory seen before
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* becoming unhashed (during a lockless path walk) when a stat
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* family system call is made the mount won't be re-mounted as
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* it should. In this case the mount point that's been removed
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* (by the daemon) will be stale and the a new mount point
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* dentry created.
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*/
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if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) {
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struct dentry *parent = dentry->d_parent;
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struct autofs_info *ino;
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struct dentry *new;
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new = d_lookup(parent, &dentry->d_name);
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if (!new)
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return NULL;
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ino = autofs_dentry_ino(new);
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ino->last_used = jiffies;
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dput(path->dentry);
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path->dentry = new;
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}
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return path->dentry;
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}
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static struct vfsmount *autofs_d_automount(struct path *path)
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{
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struct dentry *dentry = path->dentry;
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struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
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struct autofs_info *ino = autofs_dentry_ino(dentry);
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int status;
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pr_debug("dentry=%p %pd\n", dentry, dentry);
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/* The daemon never triggers a mount. */
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if (autofs_oz_mode(sbi))
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return NULL;
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/*
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* If an expire request is pending everyone must wait.
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* If the expire fails we're still mounted so continue
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* the follow and return. A return of -EAGAIN (which only
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* happens with indirect mounts) means the expire completed
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* and the directory was removed, so just go ahead and try
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* the mount.
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*/
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status = do_expire_wait(path, 0);
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if (status && status != -EAGAIN)
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return NULL;
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/* Callback to the daemon to perform the mount or wait */
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spin_lock(&sbi->fs_lock);
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if (ino->flags & AUTOFS_INF_PENDING) {
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spin_unlock(&sbi->fs_lock);
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status = autofs_mount_wait(path, 0);
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if (status)
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return ERR_PTR(status);
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goto done;
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}
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/*
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* If the dentry is a symlink it's equivalent to a directory
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* having path_is_mountpoint() true, so there's no need to call
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* back to the daemon.
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*/
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if (d_really_is_positive(dentry) && d_is_symlink(dentry)) {
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spin_unlock(&sbi->fs_lock);
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goto done;
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}
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if (!path_is_mountpoint(path)) {
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/*
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* It's possible that user space hasn't removed directories
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* after umounting a rootless multi-mount, although it
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* should. For v5 path_has_submounts() is sufficient to
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* handle this because the leaves of the directory tree under
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* the mount never trigger mounts themselves (they have an
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* autofs trigger mount mounted on them). But v4 pseudo direct
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* mounts do need the leaves to trigger mounts. In this case
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* we have no choice but to use the autofs_empty() check and
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* require user space behave.
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*/
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if (sbi->version > 4) {
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if (path_has_submounts(path)) {
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spin_unlock(&sbi->fs_lock);
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goto done;
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}
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} else {
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if (!autofs_empty(ino)) {
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spin_unlock(&sbi->fs_lock);
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goto done;
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}
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}
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ino->flags |= AUTOFS_INF_PENDING;
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spin_unlock(&sbi->fs_lock);
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status = autofs_mount_wait(path, 0);
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spin_lock(&sbi->fs_lock);
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ino->flags &= ~AUTOFS_INF_PENDING;
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if (status) {
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spin_unlock(&sbi->fs_lock);
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return ERR_PTR(status);
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}
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}
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spin_unlock(&sbi->fs_lock);
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done:
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/* Mount succeeded, check if we ended up with a new dentry */
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dentry = autofs_mountpoint_changed(path);
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if (!dentry)
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return ERR_PTR(-ENOENT);
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return NULL;
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}
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static int autofs_d_manage(const struct path *path, bool rcu_walk)
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{
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struct dentry *dentry = path->dentry;
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struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
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struct autofs_info *ino = autofs_dentry_ino(dentry);
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int status;
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pr_debug("dentry=%p %pd\n", dentry, dentry);
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/* The daemon never waits. */
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if (autofs_oz_mode(sbi)) {
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if (!path_is_mountpoint(path))
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return -EISDIR;
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return 0;
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}
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/* Wait for pending expires */
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if (do_expire_wait(path, rcu_walk) == -ECHILD)
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return -ECHILD;
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/*
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* This dentry may be under construction so wait on mount
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* completion.
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*/
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status = autofs_mount_wait(path, rcu_walk);
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if (status)
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return status;
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if (rcu_walk) {
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/* We don't need fs_lock in rcu_walk mode,
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* just testing 'AUTOFS_INF_WANT_EXPIRE' is enough.
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*
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* We only return -EISDIR when certain this isn't
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* a mount-trap.
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*/
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struct inode *inode;
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if (ino->flags & AUTOFS_INF_WANT_EXPIRE)
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return 0;
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if (path_is_mountpoint(path))
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return 0;
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inode = d_inode_rcu(dentry);
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if (inode && S_ISLNK(inode->i_mode))
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return -EISDIR;
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if (!autofs_empty(ino))
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return -EISDIR;
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return 0;
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}
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spin_lock(&sbi->fs_lock);
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/*
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* If the dentry has been selected for expire while we slept
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* on the lock then it might go away. We'll deal with that in
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* ->d_automount() and wait on a new mount if the expire
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* succeeds or return here if it doesn't (since there's no
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* mount to follow with a rootless multi-mount).
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*/
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if (!(ino->flags & AUTOFS_INF_EXPIRING)) {
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/*
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* Any needed mounting has been completed and the path
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* updated so check if this is a rootless multi-mount so
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* we can avoid needless calls ->d_automount() and avoid
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* an incorrect ELOOP error return.
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*/
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if ((!path_is_mountpoint(path) && !autofs_empty(ino)) ||
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(d_really_is_positive(dentry) && d_is_symlink(dentry)))
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status = -EISDIR;
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}
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spin_unlock(&sbi->fs_lock);
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|
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return status;
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}
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|
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/* Lookups in the root directory */
|
|
static struct dentry *autofs_lookup(struct inode *dir,
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struct dentry *dentry, unsigned int flags)
|
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{
|
|
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
|