| /* -*- c -*- --------------------------------------------------------------- * |
| * |
| * linux/fs/autofs/root.c |
| * |
| * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved |
| * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> |
| * Copyright 2001-2006 Ian Kent <raven@themaw.net> |
| * |
| * This file is part of the Linux kernel and is made available under |
| * the terms of the GNU General Public License, version 2, or at your |
| * option, any later version, incorporated herein by reference. |
| * |
| * ------------------------------------------------------------------------- */ |
| |
| #include <linux/capability.h> |
| #include <linux/errno.h> |
| #include <linux/stat.h> |
| #include <linux/slab.h> |
| #include <linux/param.h> |
| #include <linux/time.h> |
| #include <linux/compat.h> |
| #include <linux/mutex.h> |
| |
| #include "autofs_i.h" |
| |
| static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); |
| static int autofs4_dir_unlink(struct inode *,struct dentry *); |
| static int autofs4_dir_rmdir(struct inode *,struct dentry *); |
| static int autofs4_dir_mkdir(struct inode *,struct dentry *,umode_t); |
| static long autofs4_root_ioctl(struct file *,unsigned int,unsigned long); |
| #ifdef CONFIG_COMPAT |
| static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long); |
| #endif |
| static int autofs4_dir_open(struct inode *inode, struct file *file); |
| static struct dentry *autofs4_lookup(struct inode *,struct dentry *, unsigned int); |
| static struct vfsmount *autofs4_d_automount(struct path *); |
| static int autofs4_d_manage(struct dentry *, bool); |
| static void autofs4_dentry_release(struct dentry *); |
| |
| const struct file_operations autofs4_root_operations = { |
| .open = dcache_dir_open, |
| .release = dcache_dir_close, |
| .read = generic_read_dir, |
| .readdir = dcache_readdir, |
| .llseek = dcache_dir_lseek, |
| .unlocked_ioctl = autofs4_root_ioctl, |
| #ifdef CONFIG_COMPAT |
| .compat_ioctl = autofs4_root_compat_ioctl, |
| #endif |
| }; |
| |
| const struct file_operations autofs4_dir_operations = { |
| .open = autofs4_dir_open, |
| .release = dcache_dir_close, |
| .read = generic_read_dir, |
| .readdir = dcache_readdir, |
| .llseek = dcache_dir_lseek, |
| }; |
| |
| const struct inode_operations autofs4_dir_inode_operations = { |
| .lookup = autofs4_lookup, |
| .unlink = autofs4_dir_unlink, |
| .symlink = autofs4_dir_symlink, |
| .mkdir = autofs4_dir_mkdir, |
| .rmdir = autofs4_dir_rmdir, |
| }; |
| |
| const struct dentry_operations autofs4_dentry_operations = { |
| .d_automount = autofs4_d_automount, |
| .d_manage = autofs4_d_manage, |
| .d_release = autofs4_dentry_release, |
| }; |
| |
| static void autofs4_add_active(struct dentry *dentry) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| if (ino) { |
| spin_lock(&sbi->lookup_lock); |
| if (!ino->active_count) { |
| if (list_empty(&ino->active)) |
| list_add(&ino->active, &sbi->active_list); |
| } |
| ino->active_count++; |
| spin_unlock(&sbi->lookup_lock); |
| } |
| return; |
| } |
| |
| static void autofs4_del_active(struct dentry *dentry) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| if (ino) { |
| spin_lock(&sbi->lookup_lock); |
| ino->active_count--; |
| if (!ino->active_count) { |
| if (!list_empty(&ino->active)) |
| list_del_init(&ino->active); |
| } |
| spin_unlock(&sbi->lookup_lock); |
| } |
| return; |
| } |
| |
| static int autofs4_dir_open(struct inode *inode, struct file *file) |
| { |
| struct dentry *dentry = file->f_path.dentry; |
| struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| |
| DPRINTK("file=%p dentry=%p %.*s", |
| file, dentry, dentry->d_name.len, dentry->d_name.name); |
| |
| if (autofs4_oz_mode(sbi)) |
| goto out; |
| |
| /* |
| * An empty directory in an autofs file system is always a |
| * mount point. The daemon must have failed to mount this |
| * during lookup so it doesn't exist. This can happen, for |
| * example, if user space returns an incorrect status for a |
| * mount request. Otherwise we're doing a readdir on the |
| * autofs file system so just let the libfs routines handle |
| * it. |
| */ |
| spin_lock(&sbi->lookup_lock); |
| spin_lock(&dentry->d_lock); |
| if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { |
| spin_unlock(&dentry->d_lock); |
| spin_unlock(&sbi->lookup_lock); |
| return -ENOENT; |
| } |
| spin_unlock(&dentry->d_lock); |
| spin_unlock(&sbi->lookup_lock); |
| |
| out: |
| return dcache_dir_open(inode, file); |
| } |
| |
| static void autofs4_dentry_release(struct dentry *de) |
| { |
| struct autofs_info *ino = autofs4_dentry_ino(de); |
| struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); |
| |
| DPRINTK("releasing %p", de); |
| |
| if (!ino) |
| return; |
| |
| if (sbi) { |
| spin_lock(&sbi->lookup_lock); |
| if (!list_empty(&ino->active)) |
| list_del(&ino->active); |
| if (!list_empty(&ino->expiring)) |
| list_del(&ino->expiring); |
| spin_unlock(&sbi->lookup_lock); |
| } |
| |
| autofs4_free_ino(ino); |
| } |
| |
| static struct dentry *autofs4_lookup_active(struct dentry *dentry) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| struct dentry *parent = dentry->d_parent; |
| struct qstr *name = &dentry->d_name; |
| unsigned int len = name->len; |
| unsigned int hash = name->hash; |
| const unsigned char *str = name->name; |
| struct list_head *p, *head; |
| |
| spin_lock(&sbi->lookup_lock); |
| head = &sbi->active_list; |
| list_for_each(p, head) { |
| struct autofs_info *ino; |
| struct dentry *active; |
| struct qstr *qstr; |
| |
| ino = list_entry(p, struct autofs_info, active); |
| active = ino->dentry; |
| |
| spin_lock(&active->d_lock); |
| |
| /* Already gone? */ |
| if (active->d_count == 0) |
| goto next; |
| |
| qstr = &active->d_name; |
| |
| if (active->d_name.hash != hash) |
| goto next; |
| if (active->d_parent != parent) |
| goto next; |
| |
| if (qstr->len != len) |
| goto next; |
| if (memcmp(qstr->name, str, len)) |
| goto next; |
| |
| if (d_unhashed(active)) { |
| dget_dlock(active); |
| spin_unlock(&active->d_lock); |
| spin_unlock(&sbi->lookup_lock); |
| return active; |
| } |
| next: |
| spin_unlock(&active->d_lock); |
| } |
| spin_unlock(&sbi->lookup_lock); |
| |
| return NULL; |
| } |
| |
| static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| struct dentry *parent = dentry->d_parent; |
| struct qstr *name = &dentry->d_name; |
| unsigned int len = name->len; |
| unsigned int hash = name->hash; |
| const unsigned char *str = name->name; |
| struct list_head *p, *head; |
| |
| spin_lock(&sbi->lookup_lock); |
| head = &sbi->expiring_list; |
| list_for_each(p, head) { |
| struct autofs_info *ino; |
| struct dentry *expiring; |
| struct qstr *qstr; |
| |
| ino = list_entry(p, struct autofs_info, expiring); |
| expiring = ino->dentry; |
| |
| spin_lock(&expiring->d_lock); |
| |
| /* Bad luck, we've already been dentry_iput */ |
| if (!expiring->d_inode) |
| goto next; |
| |
| qstr = &expiring->d_name; |
| |
| if (expiring->d_name.hash != hash) |
| goto next; |
| if (expiring->d_parent != parent) |
| goto next; |
| |
| if (qstr->len != len) |
| goto next; |
| if (memcmp(qstr->name, str, len)) |
| goto next; |
| |
| if (d_unhashed(expiring)) { |
| dget_dlock(expiring); |
| spin_unlock(&expiring->d_lock); |
| spin_unlock(&sbi->lookup_lock); |
| return expiring; |
| } |
| next: |
| spin_unlock(&expiring->d_lock); |
| } |
| spin_unlock(&sbi->lookup_lock); |
| |
| return NULL; |
| } |
| |
| static int autofs4_mount_wait(struct dentry *dentry) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| int status = 0; |
| |
| if (ino->flags & AUTOFS_INF_PENDING) { |
| DPRINTK("waiting for mount name=%.*s", |
| dentry->d_name.len, dentry->d_name.name); |
| status = autofs4_wait(sbi, dentry, NFY_MOUNT); |
| DPRINTK("mount wait done status=%d", status); |
| } |
| ino->last_used = jiffies; |
| return status; |
| } |
| |
| static int do_expire_wait(struct dentry *dentry) |
| { |
| struct dentry *expiring; |
| |
| expiring = autofs4_lookup_expiring(dentry); |
| if (!expiring) |
| return autofs4_expire_wait(dentry); |
| else { |
| /* |
| * If we are racing with expire the request might not |
| * be quite complete, but the directory has been removed |
| * so it must have been successful, just wait for it. |
| */ |
| autofs4_expire_wait(expiring); |
| autofs4_del_expiring(expiring); |
| dput(expiring); |
| } |
| return 0; |
| } |
| |
| static struct dentry *autofs4_mountpoint_changed(struct path *path) |
| { |
| struct dentry *dentry = path->dentry; |
| struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| |
| /* |
| * If this is an indirect mount the dentry could have gone away |
| * as a result of an expire and a new one created. |
| */ |
| if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { |
| struct dentry *parent = dentry->d_parent; |
| struct autofs_info *ino; |
| struct dentry *new = d_lookup(parent, &dentry->d_name); |
| if (!new) |
| return NULL; |
| ino = autofs4_dentry_ino(new); |
| ino->last_used = jiffies; |
| dput(path->dentry); |
| path->dentry = new; |
| } |
| return path->dentry; |
| } |
| |
| static struct vfsmount *autofs4_d_automount(struct path *path) |
| { |
| struct dentry *dentry = path->dentry; |
| struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| int status; |
| |
| DPRINTK("dentry=%p %.*s", |
| dentry, dentry->d_name.len, dentry->d_name.name); |
| |
| /* The daemon never triggers a mount. */ |
| if (autofs4_oz_mode(sbi)) |
| return NULL; |
| |
| /* |
| * If an expire request is pending everyone must wait. |
| * If the expire fails we're still mounted so continue |
| * the follow and return. A return of -EAGAIN (which only |
| * happens with indirect mounts) means the expire completed |
| * and the directory was removed, so just go ahead and try |
| * the mount. |
| */ |
| status = do_expire_wait(dentry); |
| if (status && status != -EAGAIN) |
| return NULL; |
| |
| /* Callback to the daemon to perform the mount or wait */ |
| spin_lock(&sbi->fs_lock); |
| if (ino->flags & AUTOFS_INF_PENDING) { |
| spin_unlock(&sbi->fs_lock); |
| status = autofs4_mount_wait(dentry); |
| if (status) |
| return ERR_PTR(status); |
| spin_lock(&sbi->fs_lock); |
| goto done; |
| } |
| |
| /* |
| * If the dentry is a symlink it's equivalent to a directory |
| * having d_mountpoint() true, so there's no need to call back |
| * to the daemon. |
| */ |
| if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) |
| goto done; |
| if (!d_mountpoint(dentry)) { |
| /* |
| * It's possible that user space hasn't removed directories |
| * after umounting a rootless multi-mount, although it |
| * should. For v5 have_submounts() is sufficient to handle |
| * this because the leaves of the directory tree under the |
| * mount never trigger mounts themselves (they have an autofs |
| * trigger mount mounted on them). But v4 pseudo direct mounts |
| * do need the leaves to to trigger mounts. In this case we |
| * have no choice but to use the list_empty() check and |
| * require user space behave. |
| */ |
| if (sbi->version > 4) { |
| if (have_submounts(dentry)) |
| goto done; |
| } else { |
| spin_lock(&dentry->d_lock); |
| if (!list_empty(&dentry->d_subdirs)) { |
| spin_unlock(&dentry->d_lock); |
| goto done; |
| } |
| spin_unlock(&dentry->d_lock); |
| } |
| ino->flags |= AUTOFS_INF_PENDING; |
| spin_unlock(&sbi->fs_lock); |
| status = autofs4_mount_wait(dentry); |
| if (status) |
| return ERR_PTR(status); |
| spin_lock(&sbi->fs_lock); |
| ino->flags &= ~AUTOFS_INF_PENDING; |
| } |
| done: |
| if (!(ino->flags & AUTOFS_INF_EXPIRING)) { |
| /* |
| * Any needed mounting has been completed and the path |
| * updated so clear DCACHE_NEED_AUTOMOUNT so we don't |
| * call ->d_automount() on rootless multi-mounts since |
| * it can lead to an incorrect ELOOP error return. |
| * |
| * Only clear DMANAGED_AUTOMOUNT for rootless multi-mounts and |
| * symlinks as in all other cases the dentry will be covered by |
| * an actual mount so ->d_automount() won't be called during |
| * the follow. |
| */ |
| spin_lock(&dentry->d_lock); |
| if ((!d_mountpoint(dentry) && |
| !list_empty(&dentry->d_subdirs)) || |
| (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode))) |
| __managed_dentry_clear_automount(dentry); |
| spin_unlock(&dentry->d_lock); |
| } |
| spin_unlock(&sbi->fs_lock); |
| |
| /* Mount succeeded, check if we ended up with a new dentry */ |
| dentry = autofs4_mountpoint_changed(path); |
| if (!dentry) |
| return ERR_PTR(-ENOENT); |
| |
| return NULL; |
| } |
| |
| int autofs4_d_manage(struct dentry *dentry, bool rcu_walk) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
| |
| DPRINTK("dentry=%p %.*s", |
| dentry, dentry->d_name.len, dentry->d_name.name); |
| |
| /* The daemon never waits. */ |
| if (autofs4_oz_mode(sbi)) { |
| if (rcu_walk) |
| return 0; |
| if (!d_mountpoint(dentry)) |
| return -EISDIR; |
| return 0; |
| } |
| |
| /* We need to sleep, so we need pathwalk to be in ref-mode */ |
| if (rcu_walk) |
| return -ECHILD; |
| |
| /* Wait for pending expires */ |
| do_expire_wait(dentry); |
| |
| /* |
| * This dentry may be under construction so wait on mount |
| * completion. |
| */ |
| return autofs4_mount_wait(dentry); |
| } |
| |
| /* Lookups in the root directory */ |
| static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
| { |
| struct autofs_sb_info *sbi; |
| struct autofs_info *ino; |
| struct dentry *active; |
| |
| DPRINTK("name = %.*s", dentry->d_name.len, dentry->d_name.name); |
| |
| /* File name too long to exist */ |
| if (dentry->d_name.len > NAME_MAX) |
| return ERR_PTR(-ENAMETOOLONG); |
| |
| sbi = autofs4_sbi(dir->i_sb); |
| |
| DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
| current->pid, task_pgrp_nr(current), sbi->catatonic, |
| autofs4_oz_mode(sbi)); |
| |
| active = autofs4_lookup_active(dentry); |
| if (active) { |
| return active; |
| } else { |
| /* |
| * A dentry that is not within the root can never trigger a |
| * mount operation, unless the directory already exists, so we |
| * can return fail immediately. The daemon however does need |
| * to create directories within the file system. |
| */ |
| if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent)) |
| return ERR_PTR(-ENOENT); |
| |
| /* Mark entries in the root as mount triggers */ |
| if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent)) |
| __managed_dentry_set_managed(dentry); |
| |
| ino = autofs4_new_ino(sbi); |
| if (!ino) |
| return ERR_PTR(-ENOMEM); |
| |
| dentry->d_fsdata = ino; |
| ino->dentry = dentry; |
| |
| autofs4_add_active(dentry); |
| |
| d_instantiate(dentry, NULL); |
| } |
| return NULL; |
| } |
| |
| static int autofs4_dir_symlink(struct inode *dir, |
| struct dentry *dentry, |
| const char *symname) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
| struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| struct autofs_info *p_ino; |
| struct inode *inode; |
| size_t size = strlen(symname); |
| char *cp; |
| |
| DPRINTK("%s <- %.*s", symname, |
| dentry->d_name.len, dentry->d_name.name); |
| |
| if (!autofs4_oz_mode(sbi)) |
| return -EACCES; |
| |
| BUG_ON(!ino); |
| |
| autofs4_clean_ino(ino); |
| |
| autofs4_del_active(dentry); |
| |
| cp = kmalloc(size + 1, GFP_KERNEL); |
| if (!cp) |
| return -ENOMEM; |
| |
| strcpy(cp, symname); |
| |
| inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555); |
| if (!inode) { |
| kfree(cp); |
| if (!dentry->d_fsdata) |
| kfree(ino); |
| return -ENOMEM; |
| } |
| inode->i_private = cp; |
| inode->i_size = size; |
| d_add(dentry, inode); |
| |
| dget(dentry); |
| atomic_inc(&ino->count); |
| p_ino = autofs4_dentry_ino(dentry->d_parent); |
| if (p_ino && dentry->d_parent != dentry) |
| atomic_inc(&p_ino->count); |
| |
| dir->i_mtime = CURRENT_TIME; |
| |
| return 0; |
| } |
| |
| /* |
| * NOTE! |
| * |
| * Normal filesystems would do a "d_delete()" to tell the VFS dcache |
| * that the file no longer exists. However, doing that means that the |
| * VFS layer can turn the dentry into a negative dentry. We don't want |
| * this, because the unlink is probably the result of an expire. |
| * We simply d_drop it and add it to a expiring list in the super block, |
| * which allows the dentry lookup to check for an incomplete expire. |
| * |
| * If a process is blocked on the dentry waiting for the expire to finish, |
| * it will invalidate the dentry and try to mount with a new one. |
| * |
| * Also see autofs4_dir_rmdir().. |
| */ |
| static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
| struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| struct autofs_info *p_ino; |
| |
| /* This allows root to remove symlinks */ |
| if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
| return -EACCES; |
| |
| if (atomic_dec_and_test(&ino->count)) { |
| p_ino = autofs4_dentry_ino(dentry->d_parent); |
| if (p_ino && dentry->d_parent != dentry) |
| atomic_dec(&p_ino->count); |
| } |
| dput(ino->dentry); |
| |
| dentry->d_inode->i_size = 0; |
| clear_nlink(dentry->d_inode); |
| |
| dir->i_mtime = CURRENT_TIME; |
| |
| spin_lock(&sbi->lookup_lock); |
| __autofs4_add_expiring(dentry); |
| spin_lock(&dentry->d_lock); |
| __d_drop(dentry); |
| spin_unlock(&dentry->d_lock); |
| spin_unlock(&sbi->lookup_lock); |
| |
| return 0; |
| } |
| |
| /* |
| * Version 4 of autofs provides a pseudo direct mount implementation |
| * that relies on directories at the leaves of a directory tree under |
| * an indirect mount to trigger mounts. To allow for this we need to |
| * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves |
| * of the directory tree. There is no need to clear the automount flag |
| * following a mount or restore it after an expire because these mounts |
| * are always covered. However, it is necessary to ensure that these |
| * flags are clear on non-empty directories to avoid unnecessary calls |
| * during path walks. |
| */ |
| static void autofs_set_leaf_automount_flags(struct dentry *dentry) |
| { |
| struct dentry *parent; |
| |
| /* root and dentrys in the root are already handled */ |
| if (IS_ROOT(dentry->d_parent)) |
| return; |
| |
| managed_dentry_set_managed(dentry); |
| |
| parent = dentry->d_parent; |
| /* only consider parents below dentrys in the root */ |
| if (IS_ROOT(parent->d_parent)) |
| return; |
| managed_dentry_clear_managed(parent); |
| return; |
| } |
| |
| static void autofs_clear_leaf_automount_flags(struct dentry *dentry) |
| { |
| struct list_head *d_child; |
| struct dentry *parent; |
| |
| /* flags for dentrys in the root are handled elsewhere */ |
| if (IS_ROOT(dentry->d_parent)) |
| return; |
| |
| managed_dentry_clear_managed(dentry); |
| |
| parent = dentry->d_parent; |
| /* only consider parents below dentrys in the root */ |
| if (IS_ROOT(parent->d_parent)) |
| return; |
| d_child = &dentry->d_child; |
| /* Set parent managed if it's becoming empty */ |
| if (d_child->next == &parent->d_subdirs && |
| d_child->prev == &parent->d_subdirs) |
| managed_dentry_set_managed(parent); |
| return; |
| } |
| |
| static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
| struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| struct autofs_info *p_ino; |
| |
| DPRINTK("dentry %p, removing %.*s", |
| dentry, dentry->d_name.len, dentry->d_name.name); |
| |
| if (!autofs4_oz_mode(sbi)) |
| return -EACCES; |
| |
| spin_lock(&sbi->lookup_lock); |
| spin_lock(&dentry->d_lock); |
| if (!list_empty(&dentry->d_subdirs)) { |
| spin_unlock(&dentry->d_lock); |
| spin_unlock(&sbi->lookup_lock); |
| return -ENOTEMPTY; |
| } |
| __autofs4_add_expiring(dentry); |
| __d_drop(dentry); |
| spin_unlock(&dentry->d_lock); |
| spin_unlock(&sbi->lookup_lock); |
| |
| if (sbi->version < 5) |
| autofs_clear_leaf_automount_flags(dentry); |
| |
| if (atomic_dec_and_test(&ino->count)) { |
| p_ino = autofs4_dentry_ino(dentry->d_parent); |
| if (p_ino && dentry->d_parent != dentry) |
| atomic_dec(&p_ino->count); |
| } |
| dput(ino->dentry); |
| dentry->d_inode->i_size = 0; |
| clear_nlink(dentry->d_inode); |
| |
| if (dir->i_nlink) |
| drop_nlink(dir); |
| |
| return 0; |
| } |
| |
| static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
| struct autofs_info *ino = autofs4_dentry_ino(dentry); |
| struct autofs_info *p_ino; |
| struct inode *inode; |
| |
| if (!autofs4_oz_mode(sbi)) |
| return -EACCES; |
| |
| DPRINTK("dentry %p, creating %.*s", |
| dentry, dentry->d_name.len, dentry->d_name.name); |
| |
| BUG_ON(!ino); |
| |
| autofs4_clean_ino(ino); |
| |
| autofs4_del_active(dentry); |
| |
| inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555); |
| if (!inode) |
| return -ENOMEM; |
| d_add(dentry, inode); |
| |
| if (sbi->version < 5) |
| autofs_set_leaf_automount_flags(dentry); |
| |
| dget(dentry); |
| atomic_inc(&ino->count); |
| p_ino = autofs4_dentry_ino(dentry->d_parent); |
| if (p_ino && dentry->d_parent != dentry) |
| atomic_inc(&p_ino->count); |
| inc_nlink(dir); |
| dir->i_mtime = CURRENT_TIME; |
| |
| return 0; |
| } |
| |
| /* Get/set timeout ioctl() operation */ |
| #ifdef CONFIG_COMPAT |
| static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi, |
| compat_ulong_t __user *p) |
| { |
| int rv; |
| unsigned long ntimeout; |
| |
| if ((rv = get_user(ntimeout, p)) || |
| (rv = put_user(sbi->exp_timeout/HZ, p))) |
| return rv; |
| |
| if (ntimeout > UINT_MAX/HZ) |
| sbi->exp_timeout = 0; |
| else |
| sbi->exp_timeout = ntimeout * HZ; |
| |
| return 0; |
| } |
| #endif |
| |
| static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, |
| unsigned long __user *p) |
| { |
| int rv; |
| unsigned long ntimeout; |
| |
| if ((rv = get_user(ntimeout, p)) || |
| (rv = put_user(sbi->exp_timeout/HZ, p))) |
| return rv; |
| |
| if (ntimeout > ULONG_MAX/HZ) |
| sbi->exp_timeout = 0; |
| else |
| sbi->exp_timeout = ntimeout * HZ; |
| |
| return 0; |
| } |
| |
| /* Return protocol version */ |
| static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) |
| { |
| return put_user(sbi->version, p); |
| } |
| |
| /* Return protocol sub version */ |
| static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) |
| { |
| return put_user(sbi->sub_version, p); |
| } |
| |
| /* |
| * Tells the daemon whether it can umount the autofs mount. |
| */ |
| static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) |
| { |
| int status = 0; |
| |
| if (may_umount(mnt)) |
| status = 1; |
| |
| DPRINTK("returning %d", status); |
| |
| status = put_user(status, p); |
| |
| return status; |
| } |
| |
| /* Identify autofs4_dentries - this is so we can tell if there's |
| an extra dentry refcount or not. We only hold a refcount on the |
| dentry if its non-negative (ie, d_inode != NULL) |
| */ |
| int is_autofs4_dentry(struct dentry *dentry) |
| { |
| return dentry && dentry->d_inode && |
| dentry->d_op == &autofs4_dentry_operations && |
| dentry->d_fsdata != NULL; |
| } |
| |
| /* |
| * ioctl()'s on the root directory is the chief method for the daemon to |
| * generate kernel reactions |
| */ |
| static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); |
| void __user *p = (void __user *)arg; |
| |
| DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", |
| cmd,arg,sbi,task_pgrp_nr(current)); |
| |
| if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
| _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) |
| return -ENOTTY; |
| |
| if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
| return -EPERM; |
| |
| switch(cmd) { |
| case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ |
| return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); |
| case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ |
| return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); |
| case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ |
| autofs4_catatonic_mode(sbi); |
| return 0; |
| case AUTOFS_IOC_PROTOVER: /* Get protocol version */ |
| return autofs4_get_protover(sbi, p); |
| case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ |
| return autofs4_get_protosubver(sbi, p); |
| case AUTOFS_IOC_SETTIMEOUT: |
| return autofs4_get_set_timeout(sbi, p); |
| #ifdef CONFIG_COMPAT |
| case AUTOFS_IOC_SETTIMEOUT32: |
| return autofs4_compat_get_set_timeout(sbi, p); |
| #endif |
| |
| case AUTOFS_IOC_ASKUMOUNT: |
| return autofs4_ask_umount(filp->f_path.mnt, p); |
| |
| /* return a single thing to expire */ |
| case AUTOFS_IOC_EXPIRE: |
| return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
| /* same as above, but can send multiple expires through pipe */ |
| case AUTOFS_IOC_EXPIRE_MULTI: |
| return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
| |
| default: |
| return -ENOSYS; |
| } |
| } |
| |
| static long autofs4_root_ioctl(struct file *filp, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct inode *inode = filp->f_dentry->d_inode; |
| return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
| } |
| |
| #ifdef CONFIG_COMPAT |
| static long autofs4_root_compat_ioctl(struct file *filp, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct inode *inode = filp->f_path.dentry->d_inode; |
| int ret; |
| |
| if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL) |
| ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
| else |
| ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, |
| (unsigned long)compat_ptr(arg)); |
| |
| return ret; |
| } |
| #endif |