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928 lines
24 KiB
928 lines
24 KiB
// 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 <[email protected]> |
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* Copyright 2001-2006 Ian Kent <[email protected]> |
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*/ |
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|
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#include <linux/capability.h> |
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#include <linux/compat.h> |
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|
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#include "autofs_i.h" |
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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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pr_debug("file=%p dentry=%p %pd\n", file, dentry, dentry); |
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|
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if (autofs_oz_mode(sbi)) |
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goto out; |
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|
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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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|
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out: |
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return dcache_dir_open(inode, file); |
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} |
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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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|
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pr_debug("releasing %p\n", de); |
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|
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if (!ino) |
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return; |
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|
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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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|
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autofs_free_ino(ino); |
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} |
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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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|
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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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|
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ino = list_entry(p, struct autofs_info, active); |
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active = ino->dentry; |
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|
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spin_lock(&active->d_lock); |
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|
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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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|
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qstr = &active->d_name; |
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|
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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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|
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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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|
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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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|
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return NULL; |
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} |
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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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|
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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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|
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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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|
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spin_lock(&expiring->d_lock); |
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|
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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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|
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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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|
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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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|
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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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|
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return NULL; |
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} |
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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pr_debug("dentry=%p %pd\n", dentry, dentry); |
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|
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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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/* |
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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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/* |
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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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} |
|
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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status = autofs_mount_wait(path, rcu_walk); |
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if (status) |
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return status; |
|
|
|
if (rcu_walk) { |
|
/* We don't need fs_lock in rcu_walk mode, |
|
* just testing 'AUTOFS_INF_WANT_EXPIRE' is enough. |
|
* |
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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; |
|
if (path_is_mountpoint(path)) |
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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
|
|
|