#include <linux/namei.h>
#include <linux/security.h>
#include <linux/mount.h>
+#include <linux/vs_base.h>
+
#include <asm/uaccess.h>
#include <asm/unistd.h>
INIT_LIST_HEAD(&mnt->mnt_child);
INIT_LIST_HEAD(&mnt->mnt_mounts);
INIT_LIST_HEAD(&mnt->mnt_list);
- INIT_LIST_HEAD(&mnt->mnt_fslink);
if (name) {
int size = strlen(name)+1;
char *newname = kmalloc(size, GFP_KERNEL);
EXPORT_SYMBOL(lookup_mnt);
-static inline int check_mnt(struct vfsmount *mnt)
+static int check_mnt(struct vfsmount *mnt)
{
- return mnt->mnt_namespace == current->namespace;
+ spin_lock(&vfsmount_lock);
+ while (mnt->mnt_parent != mnt)
+ mnt = mnt->mnt_parent;
+ spin_unlock(&vfsmount_lock);
+ return mnt == current->namespace->root;
}
static void detach_mnt(struct vfsmount *mnt, struct nameidata *old_nd)
mnt->mnt_root = dget(root);
mnt->mnt_mountpoint = mnt->mnt_root;
mnt->mnt_parent = mnt;
- mnt->mnt_namespace = old->mnt_namespace;
-
- /* stick the duplicate mount on the same expiry list
- * as the original if that was on one */
- spin_lock(&vfsmount_lock);
- if (!list_empty(&old->mnt_fslink))
- list_add(&mnt->mnt_fslink, &old->mnt_fslink);
- spin_unlock(&vfsmount_lock);
}
return mnt;
}
};
struct proc_fs_info *fs_infop;
+ if (vx_flags(VXF_HIDE_MOUNT, 0))
+ return 0;
+
mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none");
seq_putc(m, ' ');
seq_path(m, mnt, mnt->mnt_root, " \t\n\\");
EXPORT_SYMBOL(may_umount);
-void umount_tree(struct vfsmount *mnt)
+static inline void __umount_tree(struct vfsmount *mnt, struct list_head *kill)
{
- struct vfsmount *p;
- LIST_HEAD(kill);
-
- for (p = mnt; p; p = next_mnt(p, mnt)) {
- list_del(&p->mnt_list);
- list_add(&p->mnt_list, &kill);
- }
-
- while (!list_empty(&kill)) {
- mnt = list_entry(kill.next, struct vfsmount, mnt_list);
+ while (!list_empty(kill)) {
+ mnt = list_entry(kill->next, struct vfsmount, mnt_list);
list_del_init(&mnt->mnt_list);
- list_del_init(&mnt->mnt_fslink);
if (mnt->mnt_parent == mnt) {
spin_unlock(&vfsmount_lock);
} else {
}
}
+void umount_tree(struct vfsmount *mnt)
+{
+ struct vfsmount *p;
+ LIST_HEAD(kill);
+
+ for (p = mnt; p; p = next_mnt(p, mnt)) {
+ list_del(&p->mnt_list);
+ list_add(&p->mnt_list, &kill);
+ }
+ __umount_tree(mnt, &kill);
+}
+
+void umount_unused(struct vfsmount *mnt, struct fs_struct *fs)
+{
+ struct vfsmount *p;
+ LIST_HEAD(kill);
+
+ for (p = mnt; p; p = next_mnt(p, mnt)) {
+ if (p == fs->rootmnt || p == fs->pwdmnt)
+ continue;
+ list_del(&p->mnt_list);
+ list_add(&p->mnt_list, &kill);
+ }
+ __umount_tree(mnt, &kill);
+}
+
static int do_umount(struct vfsmount *mnt, int flags)
{
struct super_block * sb = mnt->mnt_sb;
if (retval)
return retval;
- /*
- * Allow userspace to request a mountpoint be expired rather than
- * unmounting unconditionally. Unmount only happens if:
- * (1) the mark is already set (the mark is cleared by mntput())
- * (2) the usage count == 1 [parent vfsmount] + 1 [sys_umount]
- */
- if (flags & MNT_EXPIRE) {
- if (mnt == current->fs->rootmnt ||
- flags & (MNT_FORCE | MNT_DETACH))
- return -EINVAL;
-
- if (atomic_read(&mnt->mnt_count) != 2)
- return -EBUSY;
-
- if (!xchg(&mnt->mnt_expiry_mark, 1))
- return -EAGAIN;
- }
-
/*
* If we may have to abort operations to get out of this
* mount, and they will themselves hold resources we must
down_write(&sb->s_umount);
if (!(sb->s_flags & MS_RDONLY)) {
lock_kernel();
- retval = do_remount_sb(sb, MS_RDONLY, NULL, 0);
+ retval = do_remount_sb(sb, MS_RDONLY, 0, 0);
unlock_kernel();
}
up_write(&sb->s_umount);
goto dput_and_out;
retval = -EPERM;
- if (!capable(CAP_SYS_ADMIN))
+ if (!capable(CAP_SYS_ADMIN) && !vx_ccaps(VXC_SECURE_MOUNT))
goto dput_and_out;
retval = do_umount(nd.mnt, flags);
dput_and_out:
- path_release_on_umount(&nd);
+ path_release(&nd);
out:
return retval;
}
{
if (capable(CAP_SYS_ADMIN))
return 0;
+ if (vx_ccaps(VXC_SECURE_MOUNT))
+ return 0;
return -EPERM;
#ifdef notyet
if (S_ISLNK(nd->dentry->d_inode->i_mode))
}
if (mnt) {
- /* stop bind mounts from expiring */
- spin_lock(&vfsmount_lock);
- list_del_init(&mnt->mnt_fslink);
- spin_unlock(&vfsmount_lock);
-
err = graft_tree(mnt, nd);
if (err) {
spin_lock(&vfsmount_lock);
* on it - tough luck.
*/
-static int do_remount(struct nameidata *nd, int flags, int mnt_flags,
- void *data)
+static int do_remount(struct nameidata *nd,int flags,int mnt_flags,void *data)
{
int err;
struct super_block * sb = nd->mnt->mnt_sb;
detach_mnt(old_nd.mnt, &parent_nd);
attach_mnt(old_nd.mnt, nd);
-
- /* if the mount is moved, it should no longer be expire
- * automatically */
- list_del_init(&old_nd.mnt->mnt_fslink);
out2:
spin_unlock(&vfsmount_lock);
out1:
return err;
}
-/*
- * create a new mount for userspace and request it to be added into the
- * namespace's tree
- */
-static int do_new_mount(struct nameidata *nd, char *type, int flags,
+static int do_add_mount(struct nameidata *nd, char *type, int flags,
int mnt_flags, char *name, void *data)
{
struct vfsmount *mnt;
+ int err;
if (!type || !memchr(type, 0, PAGE_SIZE))
return -EINVAL;
/* we need capabilities... */
- if (!capable(CAP_SYS_ADMIN))
+ if (!capable(CAP_SYS_ADMIN) && !vx_ccaps(VXC_SECURE_MOUNT))
return -EPERM;
mnt = do_kern_mount(type, flags, name, data);
+ err = PTR_ERR(mnt);
if (IS_ERR(mnt))
- return PTR_ERR(mnt);
-
- return do_add_mount(mnt, nd, mnt_flags, NULL);
-}
-
-/*
- * add a mount into a namespace's mount tree
- * - provide the option of adding the new mount to an expiration list
- */
-int do_add_mount(struct vfsmount *newmnt, struct nameidata *nd,
- int mnt_flags, struct list_head *fslist)
-{
- int err;
+ goto out;
down_write(¤t->namespace->sem);
/* Something was mounted here while we slept */
/* Refuse the same filesystem on the same mount point */
err = -EBUSY;
- if (nd->mnt->mnt_sb == newmnt->mnt_sb &&
- nd->mnt->mnt_root == nd->dentry)
+ if (nd->mnt->mnt_sb == mnt->mnt_sb && nd->mnt->mnt_root == nd->dentry)
goto unlock;
err = -EINVAL;
- if (S_ISLNK(newmnt->mnt_root->d_inode->i_mode))
+ if (S_ISLNK(mnt->mnt_root->d_inode->i_mode))
goto unlock;
- newmnt->mnt_flags = mnt_flags;
- err = graft_tree(newmnt, nd);
-
- if (err == 0 && fslist) {
- /* add to the specified expiration list */
- spin_lock(&vfsmount_lock);
- list_add_tail(&newmnt->mnt_fslink, fslist);
- spin_unlock(&vfsmount_lock);
- }
-
+ mnt->mnt_flags = mnt_flags;
+ err = graft_tree(mnt, nd);
unlock:
up_write(¤t->namespace->sem);
- mntput(newmnt);
+ mntput(mnt);
+out:
return err;
}
-EXPORT_SYMBOL_GPL(do_add_mount);
-
-/*
- * process a list of expirable mountpoints with the intent of discarding any
- * mountpoints that aren't in use and haven't been touched since last we came
- * here
- */
-void mark_mounts_for_expiry(struct list_head *mounts)
-{
- struct namespace *namespace;
- struct vfsmount *mnt, *next;
- LIST_HEAD(graveyard);
-
- if (list_empty(mounts))
- return;
-
- spin_lock(&vfsmount_lock);
-
- /* extract from the expiration list every vfsmount that matches the
- * following criteria:
- * - only referenced by its parent vfsmount
- * - still marked for expiry (marked on the last call here; marks are
- * cleared by mntput())
- */
- list_for_each_entry_safe(mnt, next, mounts, mnt_fslink) {
- if (!xchg(&mnt->mnt_expiry_mark, 1) ||
- atomic_read(&mnt->mnt_count) != 1)
- continue;
-
- mntget(mnt);
- list_move(&mnt->mnt_fslink, &graveyard);
- }
-
- /*
- * go through the vfsmounts we've just consigned to the graveyard to
- * - check that they're still dead
- * - delete the vfsmount from the appropriate namespace under lock
- * - dispose of the corpse
- */
- while (!list_empty(&graveyard)) {
- mnt = list_entry(graveyard.next, struct vfsmount, mnt_fslink);
- list_del_init(&mnt->mnt_fslink);
-
- /* don't do anything if the namespace is dead - all the
- * vfsmounts from it are going away anyway */
- namespace = mnt->mnt_namespace;
- if (!namespace || atomic_read(&namespace->count) <= 0)
- continue;
- get_namespace(namespace);
-
- spin_unlock(&vfsmount_lock);
- down_write(&namespace->sem);
- spin_lock(&vfsmount_lock);
-
- /* check that it is still dead: the count should now be 2 - as
- * contributed by the vfsmount parent and the mntget above */
- if (atomic_read(&mnt->mnt_count) == 2) {
- struct vfsmount *xdmnt;
- struct dentry *xdentry;
-
- /* delete from the namespace */
- list_del_init(&mnt->mnt_list);
- list_del_init(&mnt->mnt_child);
- list_del_init(&mnt->mnt_hash);
- mnt->mnt_mountpoint->d_mounted--;
-
- xdentry = mnt->mnt_mountpoint;
- mnt->mnt_mountpoint = mnt->mnt_root;
- xdmnt = mnt->mnt_parent;
- mnt->mnt_parent = mnt;
-
- spin_unlock(&vfsmount_lock);
-
- mntput(xdmnt);
- dput(xdentry);
-
- /* now lay it to rest if this was the last ref on the
- * superblock */
- if (atomic_read(&mnt->mnt_sb->s_active) == 1) {
- /* last instance - try to be smart */
- lock_kernel();
- DQUOT_OFF(mnt->mnt_sb);
- acct_auto_close(mnt->mnt_sb);
- unlock_kernel();
- }
-
- mntput(mnt);
- } else {
- /* someone brought it back to life whilst we didn't
- * have any locks held so return it to the expiration
- * list */
- list_add_tail(&mnt->mnt_fslink, mounts);
- spin_unlock(&vfsmount_lock);
- }
-
- up_write(&namespace->sem);
-
- mntput(mnt);
- put_namespace(namespace);
-
- spin_lock(&vfsmount_lock);
- }
-
- spin_unlock(&vfsmount_lock);
-}
-
-EXPORT_SYMBOL_GPL(mark_mounts_for_expiry);
-
int copy_mount_options (const void __user *data, unsigned long *where)
{
int i;
mnt_flags |= MNT_NOEXEC;
flags &= ~(MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_ACTIVE);
+ if (vx_ccaps(VXC_SECURE_MOUNT))
+ mnt_flags |= MNT_NODEV;
+
/* ... and get the mountpoint */
retval = path_lookup(dir_name, LOOKUP_FOLLOW, &nd);
if (retval)
else if (flags & MS_MOVE)
retval = do_move_mount(&nd, dev_name);
else
- retval = do_new_mount(&nd, type_page, flags, mnt_flags,
+ retval = do_add_mount(&nd, type_page, flags, mnt_flags,
dev_name, data_page);
dput_out:
path_release(&nd);
struct namespace *new_ns;
struct vfsmount *rootmnt = NULL, *pwdmnt = NULL, *altrootmnt = NULL;
struct fs_struct *fs = tsk->fs;
- struct vfsmount *p, *q;
if (!namespace)
return 0;
list_add_tail(&new_ns->list, &new_ns->root->mnt_list);
spin_unlock(&vfsmount_lock);
- /*
- * Second pass: switch the tsk->fs->* elements and mark new vfsmounts
- * as belonging to new namespace. We have already acquired a private
- * fs_struct, so tsk->fs->lock is not needed.
- */
- p = namespace->root;
- q = new_ns->root;
- while (p) {
- q->mnt_namespace = new_ns;
- if (fs) {
+ /* Second pass: switch the tsk->fs->* elements */
+ if (fs) {
+ struct vfsmount *p, *q;
+ write_lock(&fs->lock);
+
+ p = namespace->root;
+ q = new_ns->root;
+ while (p) {
if (p == fs->rootmnt) {
rootmnt = p;
fs->rootmnt = mntget(q);
altrootmnt = p;
fs->altrootmnt = mntget(q);
}
+ p = next_mnt(p, namespace->root);
+ q = next_mnt(q, new_ns->root);
}
- p = next_mnt(p, namespace->root);
- q = next_mnt(q, new_ns->root);
+ write_unlock(&fs->lock);
}
up_write(&tsk->namespace->sem);
init_rwsem(&namespace->sem);
list_add(&mnt->mnt_list, &namespace->list);
namespace->root = mnt;
- mnt->mnt_namespace = namespace;
init_task.namespace = namespace;
read_lock(&tasklist_lock);
void __put_namespace(struct namespace *namespace)
{
- struct vfsmount *mnt;
-
down_write(&namespace->sem);
spin_lock(&vfsmount_lock);
-
- list_for_each_entry(mnt, &namespace->list, mnt_list) {
- mnt->mnt_namespace = NULL;
- }
-
umount_tree(namespace->root);
spin_unlock(&vfsmount_lock);
up_write(&namespace->sem);
git://git.onelab.eu / linux-2.6.git / blobdiff