*/
#include <linux/syscalls.h>
-#include <linux/slab.h>
-#include <linux/sched.h>
-#include <linux/spinlock.h>
-#include <linux/percpu.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/acct.h>
+#include <linux/export.h>
#include <linux/capability.h>
-#include <linux/cpumask.h>
-#include <linux/module.h>
-#include <linux/sysfs.h>
-#include <linux/seq_file.h>
#include <linux/mnt_namespace.h>
#include <linux/namei.h>
-#include <linux/nsproxy.h>
#include <linux/security.h>
-#include <linux/mount.h>
-#include <linux/ramfs.h>
-#include <linux/log2.h>
#include <linux/idr.h>
-#include <linux/fs_struct.h>
-#include <linux/fsnotify.h>
-#include <asm/uaccess.h>
-#include <asm/unistd.h>
+#include <linux/acct.h> /* acct_auto_close_mnt */
+#include <linux/ramfs.h> /* init_rootfs */
+#include <linux/fs_struct.h> /* get_fs_root et.al. */
+#include <linux/fsnotify.h> /* fsnotify_vfsmount_delete */
+#include <linux/uaccess.h>
#include "pnode.h"
#include "internal.h"
* allocation is serialized by namespace_sem, but we need the spinlock to
* serialize with freeing.
*/
-static int mnt_alloc_id(struct vfsmount *mnt)
+static int mnt_alloc_id(struct mount *mnt)
{
int res;
return res;
}
-static void mnt_free_id(struct vfsmount *mnt)
+static void mnt_free_id(struct mount *mnt)
{
int id = mnt->mnt_id;
spin_lock(&mnt_id_lock);
*
* mnt_group_ida is protected by namespace_sem
*/
-static int mnt_alloc_group_id(struct vfsmount *mnt)
+static int mnt_alloc_group_id(struct mount *mnt)
{
int res;
/*
* Release a peer group ID
*/
-void mnt_release_group_id(struct vfsmount *mnt)
+void mnt_release_group_id(struct mount *mnt)
{
int id = mnt->mnt_group_id;
ida_remove(&mnt_group_ida, id);
/*
* vfsmount lock must be held for read
*/
-static inline void mnt_add_count(struct vfsmount *mnt, int n)
+static inline void mnt_add_count(struct mount *mnt, int n)
{
#ifdef CONFIG_SMP
this_cpu_add(mnt->mnt_pcp->mnt_count, n);
#endif
}
-static inline void mnt_set_count(struct vfsmount *mnt, int n)
-{
-#ifdef CONFIG_SMP
- this_cpu_write(mnt->mnt_pcp->mnt_count, n);
-#else
- mnt->mnt_count = n;
-#endif
-}
-
-/*
- * vfsmount lock must be held for read
- */
-static inline void mnt_inc_count(struct vfsmount *mnt)
-{
- mnt_add_count(mnt, 1);
-}
-
-/*
- * vfsmount lock must be held for read
- */
-static inline void mnt_dec_count(struct vfsmount *mnt)
-{
- mnt_add_count(mnt, -1);
-}
-
/*
* vfsmount lock must be held for write
*/
-unsigned int mnt_get_count(struct vfsmount *mnt)
+unsigned int mnt_get_count(struct mount *mnt)
{
#ifdef CONFIG_SMP
unsigned int count = 0;
#endif
}
-static struct vfsmount *alloc_vfsmnt(const char *name)
+static struct mount *alloc_vfsmnt(const char *name)
{
- struct vfsmount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
+ struct mount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
if (mnt) {
int err;
}
EXPORT_SYMBOL_GPL(__mnt_is_readonly);
-static inline void mnt_inc_writers(struct vfsmount *mnt)
+static inline void mnt_inc_writers(struct mount *mnt)
{
#ifdef CONFIG_SMP
this_cpu_inc(mnt->mnt_pcp->mnt_writers);
#endif
}
-static inline void mnt_dec_writers(struct vfsmount *mnt)
+static inline void mnt_dec_writers(struct mount *mnt)
{
#ifdef CONFIG_SMP
this_cpu_dec(mnt->mnt_pcp->mnt_writers);
#endif
}
-static unsigned int mnt_get_writers(struct vfsmount *mnt)
+static unsigned int mnt_get_writers(struct mount *mnt)
{
#ifdef CONFIG_SMP
unsigned int count = 0;
#endif
}
+static int mnt_is_readonly(struct vfsmount *mnt)
+{
+ if (mnt->mnt_sb->s_readonly_remount)
+ return 1;
+ /* Order wrt setting s_flags/s_readonly_remount in do_remount() */
+ smp_rmb();
+ return __mnt_is_readonly(mnt);
+}
+
/*
* Most r/o checks on a fs are for operations that take
* discrete amounts of time, like a write() or unlink().
*/
/**
* mnt_want_write - get write access to a mount
- * @mnt: the mount on which to take a write
+ * @m: the mount on which to take a write
*
* This tells the low-level filesystem that a write is
* about to be performed to it, and makes sure that
* the write operation is finished, mnt_drop_write()
* must be called. This is effectively a refcount.
*/
-int mnt_want_write(struct vfsmount *mnt)
+int mnt_want_write(struct vfsmount *m)
{
+ struct mount *mnt = real_mount(m);
int ret = 0;
preempt_disable();
* incremented count after it has set MNT_WRITE_HOLD.
*/
smp_mb();
- while (mnt->mnt_flags & MNT_WRITE_HOLD)
+ while (mnt->mnt.mnt_flags & MNT_WRITE_HOLD)
cpu_relax();
/*
* After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will
* MNT_WRITE_HOLD is cleared.
*/
smp_rmb();
- if (__mnt_is_readonly(mnt)) {
+ if (mnt_is_readonly(m)) {
mnt_dec_writers(mnt);
ret = -EROFS;
- goto out;
}
-out:
preempt_enable();
return ret;
}
if (__mnt_is_readonly(mnt))
return -EROFS;
preempt_disable();
- mnt_inc_writers(mnt);
+ mnt_inc_writers(real_mount(mnt));
preempt_enable();
return 0;
}
void mnt_drop_write(struct vfsmount *mnt)
{
preempt_disable();
- mnt_dec_writers(mnt);
+ mnt_dec_writers(real_mount(mnt));
preempt_enable();
}
EXPORT_SYMBOL_GPL(mnt_drop_write);
-static int mnt_make_readonly(struct vfsmount *mnt)
+void mnt_drop_write_file(struct file *file)
+{
+ mnt_drop_write(file->f_path.mnt);
+}
+EXPORT_SYMBOL(mnt_drop_write_file);
+
+static int mnt_make_readonly(struct mount *mnt)
{
int ret = 0;
br_write_lock(vfsmount_lock);
- mnt->mnt_flags |= MNT_WRITE_HOLD;
+ mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;
/*
* After storing MNT_WRITE_HOLD, we'll read the counters. This store
* should be visible before we do.
if (mnt_get_writers(mnt) > 0)
ret = -EBUSY;
else
- mnt->mnt_flags |= MNT_READONLY;
+ mnt->mnt.mnt_flags |= MNT_READONLY;
/*
* MNT_READONLY must become visible before ~MNT_WRITE_HOLD, so writers
* that become unheld will see MNT_READONLY.
*/
smp_wmb();
- mnt->mnt_flags &= ~MNT_WRITE_HOLD;
+ mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD;
br_write_unlock(vfsmount_lock);
return ret;
}
-static void __mnt_unmake_readonly(struct vfsmount *mnt)
+static void __mnt_unmake_readonly(struct mount *mnt)
{
br_write_lock(vfsmount_lock);
- mnt->mnt_flags &= ~MNT_READONLY;
+ mnt->mnt.mnt_flags &= ~MNT_READONLY;
+ br_write_unlock(vfsmount_lock);
+}
+
+int sb_prepare_remount_readonly(struct super_block *sb)
+{
+ struct mount *mnt;
+ int err = 0;
+
+ /* Racy optimization. Recheck the counter under MNT_WRITE_HOLD */
+ if (atomic_long_read(&sb->s_remove_count))
+ return -EBUSY;
+
+ br_write_lock(vfsmount_lock);
+ list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) {
+ if (!(mnt->mnt.mnt_flags & MNT_READONLY)) {
+ mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;
+ smp_mb();
+ if (mnt_get_writers(mnt) > 0) {
+ err = -EBUSY;
+ break;
+ }
+ }
+ }
+ if (!err && atomic_long_read(&sb->s_remove_count))
+ err = -EBUSY;
+
+ if (!err) {
+ sb->s_readonly_remount = 1;
+ smp_wmb();
+ }
+ list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) {
+ if (mnt->mnt.mnt_flags & MNT_WRITE_HOLD)
+ mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD;
+ }
br_write_unlock(vfsmount_lock);
+
+ return err;
}
-static void free_vfsmnt(struct vfsmount *mnt)
+static void free_vfsmnt(struct mount *mnt)
{
kfree(mnt->mnt_devname);
mnt_free_id(mnt);
* @dir. If @dir is set return the first mount else return the last mount.
* vfsmount_lock must be held for read or write.
*/
-struct vfsmount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry,
+struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry,
int dir)
{
struct list_head *head = mount_hashtable + hash(mnt, dentry);
struct list_head *tmp = head;
- struct vfsmount *p, *found = NULL;
+ struct mount *p, *found = NULL;
for (;;) {
tmp = dir ? tmp->next : tmp->prev;
p = NULL;
if (tmp == head)
break;
- p = list_entry(tmp, struct vfsmount, mnt_hash);
- if (p->mnt_parent == mnt && p->mnt_mountpoint == dentry) {
+ p = list_entry(tmp, struct mount, mnt_hash);
+ if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry) {
found = p;
break;
}
*/
struct vfsmount *lookup_mnt(struct path *path)
{
- struct vfsmount *child_mnt;
+ struct mount *child_mnt;
br_read_lock(vfsmount_lock);
- if ((child_mnt = __lookup_mnt(path->mnt, path->dentry, 1)))
- mntget(child_mnt);
- br_read_unlock(vfsmount_lock);
- return child_mnt;
+ child_mnt = __lookup_mnt(path->mnt, path->dentry, 1);
+ if (child_mnt) {
+ mnt_add_count(child_mnt, 1);
+ br_read_unlock(vfsmount_lock);
+ return &child_mnt->mnt;
+ } else {
+ br_read_unlock(vfsmount_lock);
+ return NULL;
+ }
}
-static inline int check_mnt(struct vfsmount *mnt)
+static inline int check_mnt(struct mount *mnt)
{
return mnt->mnt_ns == current->nsproxy->mnt_ns;
}
* Clear dentry's mounted state if it has no remaining mounts.
* vfsmount_lock must be held for write.
*/
-static void dentry_reset_mounted(struct vfsmount *mnt, struct dentry *dentry)
+static void dentry_reset_mounted(struct dentry *dentry)
{
unsigned u;
for (u = 0; u < HASH_SIZE; u++) {
- struct vfsmount *p;
+ struct mount *p;
list_for_each_entry(p, &mount_hashtable[u], mnt_hash) {
if (p->mnt_mountpoint == dentry)
/*
* vfsmount lock must be held for write
*/
-static void detach_mnt(struct vfsmount *mnt, struct path *old_path)
+static void detach_mnt(struct mount *mnt, struct path *old_path)
{
old_path->dentry = mnt->mnt_mountpoint;
- old_path->mnt = mnt->mnt_parent;
+ old_path->mnt = &mnt->mnt_parent->mnt;
mnt->mnt_parent = mnt;
- mnt->mnt_mountpoint = mnt->mnt_root;
+ mnt->mnt_mountpoint = mnt->mnt.mnt_root;
list_del_init(&mnt->mnt_child);
list_del_init(&mnt->mnt_hash);
- dentry_reset_mounted(old_path->mnt, old_path->dentry);
+ dentry_reset_mounted(old_path->dentry);
}
/*
* vfsmount lock must be held for write
*/
-void mnt_set_mountpoint(struct vfsmount *mnt, struct dentry *dentry,
- struct vfsmount *child_mnt)
+void mnt_set_mountpoint(struct mount *mnt, struct dentry *dentry,
+ struct mount *child_mnt)
{
- child_mnt->mnt_parent = mntget(mnt);
+ mnt_add_count(mnt, 1); /* essentially, that's mntget */
child_mnt->mnt_mountpoint = dget(dentry);
+ child_mnt->mnt_parent = mnt;
spin_lock(&dentry->d_lock);
dentry->d_flags |= DCACHE_MOUNTED;
spin_unlock(&dentry->d_lock);
/*
* vfsmount lock must be held for write
*/
-static void attach_mnt(struct vfsmount *mnt, struct path *path)
+static void attach_mnt(struct mount *mnt, struct path *path)
{
- mnt_set_mountpoint(path->mnt, path->dentry, mnt);
+ mnt_set_mountpoint(real_mount(path->mnt), path->dentry, mnt);
list_add_tail(&mnt->mnt_hash, mount_hashtable +
hash(path->mnt, path->dentry));
- list_add_tail(&mnt->mnt_child, &path->mnt->mnt_mounts);
+ list_add_tail(&mnt->mnt_child, &real_mount(path->mnt)->mnt_mounts);
}
-static inline void __mnt_make_longterm(struct vfsmount *mnt)
+static inline void __mnt_make_longterm(struct mount *mnt)
{
#ifdef CONFIG_SMP
atomic_inc(&mnt->mnt_longterm);
}
/* needs vfsmount lock for write */
-static inline void __mnt_make_shortterm(struct vfsmount *mnt)
+static inline void __mnt_make_shortterm(struct mount *mnt)
{
#ifdef CONFIG_SMP
atomic_dec(&mnt->mnt_longterm);
/*
* vfsmount lock must be held for write
*/
-static void commit_tree(struct vfsmount *mnt)
+static void commit_tree(struct mount *mnt)
{
- struct vfsmount *parent = mnt->mnt_parent;
- struct vfsmount *m;
+ struct mount *parent = mnt->mnt_parent;
+ struct mount *m;
LIST_HEAD(head);
struct mnt_namespace *n = parent->mnt_ns;
list_splice(&head, n->list.prev);
list_add_tail(&mnt->mnt_hash, mount_hashtable +
- hash(parent, mnt->mnt_mountpoint));
+ hash(&parent->mnt, mnt->mnt_mountpoint));
list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
touch_mnt_namespace(n);
}
-static struct vfsmount *next_mnt(struct vfsmount *p, struct vfsmount *root)
+static struct mount *next_mnt(struct mount *p, struct mount *root)
{
struct list_head *next = p->mnt_mounts.next;
if (next == &p->mnt_mounts) {
p = p->mnt_parent;
}
}
- return list_entry(next, struct vfsmount, mnt_child);
+ return list_entry(next, struct mount, mnt_child);
}
-static struct vfsmount *skip_mnt_tree(struct vfsmount *p)
+static struct mount *skip_mnt_tree(struct mount *p)
{
struct list_head *prev = p->mnt_mounts.prev;
while (prev != &p->mnt_mounts) {
- p = list_entry(prev, struct vfsmount, mnt_child);
+ p = list_entry(prev, struct mount, mnt_child);
prev = p->mnt_mounts.prev;
}
return p;
struct vfsmount *
vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
{
- struct vfsmount *mnt;
+ struct mount *mnt;
struct dentry *root;
if (!type)
return ERR_PTR(-ENOMEM);
if (flags & MS_KERNMOUNT)
- mnt->mnt_flags = MNT_INTERNAL;
+ mnt->mnt.mnt_flags = MNT_INTERNAL;
root = mount_fs(type, flags, name, data);
if (IS_ERR(root)) {
return ERR_CAST(root);
}
- mnt->mnt_root = root;
- mnt->mnt_sb = root->d_sb;
- mnt->mnt_mountpoint = mnt->mnt_root;
+ mnt->mnt.mnt_root = root;
+ mnt->mnt.mnt_sb = root->d_sb;
+ mnt->mnt_mountpoint = mnt->mnt.mnt_root;
mnt->mnt_parent = mnt;
- return mnt;
+ br_write_lock(vfsmount_lock);
+ list_add_tail(&mnt->mnt_instance, &root->d_sb->s_mounts);
+ br_write_unlock(vfsmount_lock);
+ return &mnt->mnt;
}
EXPORT_SYMBOL_GPL(vfs_kern_mount);
-static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root,
+static struct mount *clone_mnt(struct mount *old, struct dentry *root,
int flag)
{
- struct super_block *sb = old->mnt_sb;
- struct vfsmount *mnt = alloc_vfsmnt(old->mnt_devname);
+ struct super_block *sb = old->mnt.mnt_sb;
+ struct mount *mnt = alloc_vfsmnt(old->mnt_devname);
if (mnt) {
if (flag & (CL_SLAVE | CL_PRIVATE))
goto out_free;
}
- mnt->mnt_flags = old->mnt_flags & ~MNT_WRITE_HOLD;
+ mnt->mnt.mnt_flags = old->mnt.mnt_flags & ~MNT_WRITE_HOLD;
atomic_inc(&sb->s_active);
- mnt->mnt_sb = sb;
- mnt->mnt_root = dget(root);
- mnt->mnt_mountpoint = mnt->mnt_root;
+ mnt->mnt.mnt_sb = sb;
+ mnt->mnt.mnt_root = dget(root);
+ mnt->mnt_mountpoint = mnt->mnt.mnt_root;
mnt->mnt_parent = mnt;
+ br_write_lock(vfsmount_lock);
+ list_add_tail(&mnt->mnt_instance, &sb->s_mounts);
+ br_write_unlock(vfsmount_lock);
if (flag & CL_SLAVE) {
list_add(&mnt->mnt_slave, &old->mnt_slave_list);
return NULL;
}
-static inline void mntfree(struct vfsmount *mnt)
+static inline void mntfree(struct mount *mnt)
{
- struct super_block *sb = mnt->mnt_sb;
+ struct vfsmount *m = &mnt->mnt;
+ struct super_block *sb = m->mnt_sb;
/*
* This probably indicates that somebody messed
* so mnt_get_writers() below is safe.
*/
WARN_ON(mnt_get_writers(mnt));
- fsnotify_vfsmount_delete(mnt);
- dput(mnt->mnt_root);
+ fsnotify_vfsmount_delete(m);
+ dput(m->mnt_root);
free_vfsmnt(mnt);
deactivate_super(sb);
}
-static void mntput_no_expire(struct vfsmount *mnt)
+static void mntput_no_expire(struct mount *mnt)
{
put_again:
#ifdef CONFIG_SMP
br_read_lock(vfsmount_lock);
if (likely(atomic_read(&mnt->mnt_longterm))) {
- mnt_dec_count(mnt);
+ mnt_add_count(mnt, -1);
br_read_unlock(vfsmount_lock);
return;
}
br_read_unlock(vfsmount_lock);
br_write_lock(vfsmount_lock);
- mnt_dec_count(mnt);
+ mnt_add_count(mnt, -1);
if (mnt_get_count(mnt)) {
br_write_unlock(vfsmount_lock);
return;
}
#else
- mnt_dec_count(mnt);
+ mnt_add_count(mnt, -1);
if (likely(mnt_get_count(mnt)))
return;
br_write_lock(vfsmount_lock);
mnt_add_count(mnt, mnt->mnt_pinned + 1);
mnt->mnt_pinned = 0;
br_write_unlock(vfsmount_lock);
- acct_auto_close_mnt(mnt);
+ acct_auto_close_mnt(&mnt->mnt);
goto put_again;
}
+ list_del(&mnt->mnt_instance);
br_write_unlock(vfsmount_lock);
mntfree(mnt);
}
void mntput(struct vfsmount *mnt)
{
if (mnt) {
+ struct mount *m = real_mount(mnt);
/* avoid cacheline pingpong, hope gcc doesn't get "smart" */
- if (unlikely(mnt->mnt_expiry_mark))
- mnt->mnt_expiry_mark = 0;
- mntput_no_expire(mnt);
+ if (unlikely(m->mnt_expiry_mark))
+ m->mnt_expiry_mark = 0;
+ mntput_no_expire(m);
}
}
EXPORT_SYMBOL(mntput);
struct vfsmount *mntget(struct vfsmount *mnt)
{
if (mnt)
- mnt_inc_count(mnt);
+ mnt_add_count(real_mount(mnt), 1);
return mnt;
}
EXPORT_SYMBOL(mntget);
void mnt_pin(struct vfsmount *mnt)
{
br_write_lock(vfsmount_lock);
- mnt->mnt_pinned++;
+ real_mount(mnt)->mnt_pinned++;
br_write_unlock(vfsmount_lock);
}
EXPORT_SYMBOL(mnt_pin);
-void mnt_unpin(struct vfsmount *mnt)
+void mnt_unpin(struct vfsmount *m)
{
+ struct mount *mnt = real_mount(m);
br_write_lock(vfsmount_lock);
if (mnt->mnt_pinned) {
- mnt_inc_count(mnt);
+ mnt_add_count(mnt, 1);
mnt->mnt_pinned--;
}
br_write_unlock(vfsmount_lock);
*
* See also save_mount_options().
*/
-int generic_show_options(struct seq_file *m, struct vfsmount *mnt)
+int generic_show_options(struct seq_file *m, struct dentry *root)
{
const char *options;
rcu_read_lock();
- options = rcu_dereference(mnt->mnt_sb->s_options);
+ options = rcu_dereference(root->d_sb->s_options);
if (options != NULL && options[0]) {
seq_putc(m, ',');
EXPORT_SYMBOL(replace_mount_options);
#ifdef CONFIG_PROC_FS
-/* iterator */
+/* iterator; we want it to have access to namespace_sem, thus here... */
static void *m_start(struct seq_file *m, loff_t *pos)
{
- struct proc_mounts *p = m->private;
+ struct proc_mounts *p = container_of(m, struct proc_mounts, m);
down_read(&namespace_sem);
return seq_list_start(&p->ns->list, *pos);
static void *m_next(struct seq_file *m, void *v, loff_t *pos)
{
- struct proc_mounts *p = m->private;
+ struct proc_mounts *p = container_of(m, struct proc_mounts, m);
return seq_list_next(v, &p->ns->list, pos);
}
up_read(&namespace_sem);
}
-int mnt_had_events(struct proc_mounts *p)
+static int m_show(struct seq_file *m, void *v)
{
- struct mnt_namespace *ns = p->ns;
- int res = 0;
-
- br_read_lock(vfsmount_lock);
- if (p->m.poll_event != ns->event) {
- p->m.poll_event = ns->event;
- res = 1;
- }
- br_read_unlock(vfsmount_lock);
-
- return res;
-}
-
-struct proc_fs_info {
- int flag;
- const char *str;
-};
-
-static int show_sb_opts(struct seq_file *m, struct super_block *sb)
-{
- static const struct proc_fs_info fs_info[] = {
- { MS_SYNCHRONOUS, ",sync" },
- { MS_DIRSYNC, ",dirsync" },
- { MS_MANDLOCK, ",mand" },
- { 0, NULL }
- };
- const struct proc_fs_info *fs_infop;
-
- for (fs_infop = fs_info; fs_infop->flag; fs_infop++) {
- if (sb->s_flags & fs_infop->flag)
- seq_puts(m, fs_infop->str);
- }
-
- return security_sb_show_options(m, sb);
-}
-
-static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)
-{
- static const struct proc_fs_info mnt_info[] = {
- { MNT_NOSUID, ",nosuid" },
- { MNT_NODEV, ",nodev" },
- { MNT_NOEXEC, ",noexec" },
- { MNT_NOATIME, ",noatime" },
- { MNT_NODIRATIME, ",nodiratime" },
- { MNT_RELATIME, ",relatime" },
- { 0, NULL }
- };
- const struct proc_fs_info *fs_infop;
-
- for (fs_infop = mnt_info; fs_infop->flag; fs_infop++) {
- if (mnt->mnt_flags & fs_infop->flag)
- seq_puts(m, fs_infop->str);
- }
-}
-
-static void show_type(struct seq_file *m, struct super_block *sb)
-{
- mangle(m, sb->s_type->name);
- if (sb->s_subtype && sb->s_subtype[0]) {
- seq_putc(m, '.');
- mangle(m, sb->s_subtype);
- }
-}
-
-static int show_vfsmnt(struct seq_file *m, void *v)
-{
- struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list);
- int err = 0;
- struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
-
- if (mnt->mnt_sb->s_op->show_devname) {
- err = mnt->mnt_sb->s_op->show_devname(m, mnt);
- if (err)
- goto out;
- } else {
- mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none");
- }
- seq_putc(m, ' ');
- seq_path(m, &mnt_path, " \t\n\\");
- seq_putc(m, ' ');
- show_type(m, mnt->mnt_sb);
- seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
- err = show_sb_opts(m, mnt->mnt_sb);
- if (err)
- goto out;
- show_mnt_opts(m, mnt);
- if (mnt->mnt_sb->s_op->show_options)
- err = mnt->mnt_sb->s_op->show_options(m, mnt);
- seq_puts(m, " 0 0\n");
-out:
- return err;
+ struct proc_mounts *p = container_of(m, struct proc_mounts, m);
+ struct mount *r = list_entry(v, struct mount, mnt_list);
+ return p->show(m, &r->mnt);
}
const struct seq_operations mounts_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
- .show = show_vfsmnt
-};
-
-static int show_mountinfo(struct seq_file *m, void *v)
-{
- struct proc_mounts *p = m->private;
- struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list);
- struct super_block *sb = mnt->mnt_sb;
- struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
- struct path root = p->root;
- int err = 0;
-
- seq_printf(m, "%i %i %u:%u ", mnt->mnt_id, mnt->mnt_parent->mnt_id,
- MAJOR(sb->s_dev), MINOR(sb->s_dev));
- if (sb->s_op->show_path)
- err = sb->s_op->show_path(m, mnt);
- else
- seq_dentry(m, mnt->mnt_root, " \t\n\\");
- if (err)
- goto out;
- seq_putc(m, ' ');
-
- /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
- err = seq_path_root(m, &mnt_path, &root, " \t\n\\");
- if (err)
- goto out;
-
- seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
- show_mnt_opts(m, mnt);
-
- /* Tagged fields ("foo:X" or "bar") */
- if (IS_MNT_SHARED(mnt))
- seq_printf(m, " shared:%i", mnt->mnt_group_id);
- if (IS_MNT_SLAVE(mnt)) {
- int master = mnt->mnt_master->mnt_group_id;
- int dom = get_dominating_id(mnt, &p->root);
- seq_printf(m, " master:%i", master);
- if (dom && dom != master)
- seq_printf(m, " propagate_from:%i", dom);
- }
- if (IS_MNT_UNBINDABLE(mnt))
- seq_puts(m, " unbindable");
-
- /* Filesystem specific data */
- seq_puts(m, " - ");
- show_type(m, sb);
- seq_putc(m, ' ');
- if (sb->s_op->show_devname)
- err = sb->s_op->show_devname(m, mnt);
- else
- mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none");
- if (err)
- goto out;
- seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
- err = show_sb_opts(m, sb);
- if (err)
- goto out;
- if (sb->s_op->show_options)
- err = sb->s_op->show_options(m, mnt);
- seq_putc(m, '\n');
-out:
- return err;
-}
-
-const struct seq_operations mountinfo_op = {
- .start = m_start,
- .next = m_next,
- .stop = m_stop,
- .show = show_mountinfo,
-};
-
-static int show_vfsstat(struct seq_file *m, void *v)
-{
- struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list);
- struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
- int err = 0;
-
- /* device */
- if (mnt->mnt_sb->s_op->show_devname) {
- seq_puts(m, "device ");
- err = mnt->mnt_sb->s_op->show_devname(m, mnt);
- } else {
- if (mnt->mnt_devname) {
- seq_puts(m, "device ");
- mangle(m, mnt->mnt_devname);
- } else
- seq_puts(m, "no device");
- }
-
- /* mount point */
- seq_puts(m, " mounted on ");
- seq_path(m, &mnt_path, " \t\n\\");
- seq_putc(m, ' ');
-
- /* file system type */
- seq_puts(m, "with fstype ");
- show_type(m, mnt->mnt_sb);
-
- /* optional statistics */
- if (mnt->mnt_sb->s_op->show_stats) {
- seq_putc(m, ' ');
- if (!err)
- err = mnt->mnt_sb->s_op->show_stats(m, mnt);
- }
-
- seq_putc(m, '\n');
- return err;
-}
-
-const struct seq_operations mountstats_op = {
- .start = m_start,
- .next = m_next,
- .stop = m_stop,
- .show = show_vfsstat,
+ .show = m_show,
};
#endif /* CONFIG_PROC_FS */
* open files, pwds, chroots or sub mounts that are
* busy.
*/
-int may_umount_tree(struct vfsmount *mnt)
+int may_umount_tree(struct vfsmount *m)
{
+ struct mount *mnt = real_mount(m);
int actual_refs = 0;
int minimum_refs = 0;
- struct vfsmount *p;
+ struct mount *p;
+ BUG_ON(!m);
/* write lock needed for mnt_get_count */
br_write_lock(vfsmount_lock);
int ret = 1;
down_read(&namespace_sem);
br_write_lock(vfsmount_lock);
- if (propagate_mount_busy(mnt, 2))
+ if (propagate_mount_busy(real_mount(mnt), 2))
ret = 0;
br_write_unlock(vfsmount_lock);
up_read(&namespace_sem);
void release_mounts(struct list_head *head)
{
- struct vfsmount *mnt;
+ struct mount *mnt;
while (!list_empty(head)) {
- mnt = list_first_entry(head, struct vfsmount, mnt_hash);
+ mnt = list_first_entry(head, struct mount, mnt_hash);
list_del_init(&mnt->mnt_hash);
- if (mnt->mnt_parent != mnt) {
+ if (mnt_has_parent(mnt)) {
struct dentry *dentry;
- struct vfsmount *m;
+ struct mount *m;
br_write_lock(vfsmount_lock);
dentry = mnt->mnt_mountpoint;
m = mnt->mnt_parent;
- mnt->mnt_mountpoint = mnt->mnt_root;
+ mnt->mnt_mountpoint = mnt->mnt.mnt_root;
mnt->mnt_parent = mnt;
m->mnt_ghosts--;
br_write_unlock(vfsmount_lock);
dput(dentry);
- mntput(m);
+ mntput(&m->mnt);
}
- mntput(mnt);
+ mntput(&mnt->mnt);
}
}
* vfsmount lock must be held for write
* namespace_sem must be held for write
*/
-void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill)
+void umount_tree(struct mount *mnt, int propagate, struct list_head *kill)
{
LIST_HEAD(tmp_list);
- struct vfsmount *p;
+ struct mount *p;
for (p = mnt; p; p = next_mnt(p, mnt))
list_move(&p->mnt_hash, &tmp_list);
p->mnt_ns = NULL;
__mnt_make_shortterm(p);
list_del_init(&p->mnt_child);
- if (p->mnt_parent != p) {
+ if (mnt_has_parent(p)) {
p->mnt_parent->mnt_ghosts++;
- dentry_reset_mounted(p->mnt_parent, p->mnt_mountpoint);
+ dentry_reset_mounted(p->mnt_mountpoint);
}
change_mnt_propagation(p, MS_PRIVATE);
}
list_splice(&tmp_list, kill);
}
-static void shrink_submounts(struct vfsmount *mnt, struct list_head *umounts);
+static void shrink_submounts(struct mount *mnt, struct list_head *umounts);
-static int do_umount(struct vfsmount *mnt, int flags)
+static int do_umount(struct mount *mnt, int flags)
{
- struct super_block *sb = mnt->mnt_sb;
+ struct super_block *sb = mnt->mnt.mnt_sb;
int retval;
LIST_HEAD(umount_list);
- retval = security_sb_umount(mnt, flags);
+ retval = security_sb_umount(&mnt->mnt, flags);
if (retval)
return retval;
* (2) the usage count == 1 [parent vfsmount] + 1 [sys_umount]
*/
if (flags & MNT_EXPIRE) {
- if (mnt == current->fs->root.mnt ||
+ if (&mnt->mnt == current->fs->root.mnt ||
flags & (MNT_FORCE | MNT_DETACH))
return -EINVAL;
* /reboot - static binary that would close all descriptors and
* call reboot(9). Then init(8) could umount root and exec /reboot.
*/
- if (mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) {
+ if (&mnt->mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) {
/*
* Special case for "unmounting" root ...
* we just try to remount it readonly.
SYSCALL_DEFINE2(umount, char __user *, name, int, flags)
{
struct path path;
+ struct mount *mnt;
int retval;
int lookup_flags = 0;
retval = user_path_at(AT_FDCWD, name, lookup_flags, &path);
if (retval)
goto out;
+ mnt = real_mount(path.mnt);
retval = -EINVAL;
if (path.dentry != path.mnt->mnt_root)
goto dput_and_out;
- if (!check_mnt(path.mnt))
+ if (!check_mnt(mnt))
goto dput_and_out;
retval = -EPERM;
if (!capable(CAP_SYS_ADMIN))
goto dput_and_out;
- retval = do_umount(path.mnt, flags);
+ retval = do_umount(mnt, flags);
dput_and_out:
/* we mustn't call path_put() as that would clear mnt_expiry_mark */
dput(path.dentry);
- mntput_no_expire(path.mnt);
+ mntput_no_expire(mnt);
out:
return retval;
}
#endif
}
-struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry,
+struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
int flag)
{
- struct vfsmount *res, *p, *q, *r, *s;
+ struct mount *res, *p, *q, *r;
struct path path;
if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(mnt))
p = mnt;
list_for_each_entry(r, &mnt->mnt_mounts, mnt_child) {
+ struct mount *s;
if (!is_subdir(r->mnt_mountpoint, dentry))
continue;
q = q->mnt_parent;
}
p = s;
- path.mnt = q;
+ path.mnt = &q->mnt;
path.dentry = p->mnt_mountpoint;
- q = clone_mnt(p, p->mnt_root, flag);
+ q = clone_mnt(p, p->mnt.mnt_root, flag);
if (!q)
goto Enomem;
br_write_lock(vfsmount_lock);
struct vfsmount *collect_mounts(struct path *path)
{
- struct vfsmount *tree;
+ struct mount *tree;
down_write(&namespace_sem);
- tree = copy_tree(path->mnt, path->dentry, CL_COPY_ALL | CL_PRIVATE);
+ tree = copy_tree(real_mount(path->mnt), path->dentry,
+ CL_COPY_ALL | CL_PRIVATE);
up_write(&namespace_sem);
- return tree;
+ return tree ? &tree->mnt : NULL;
}
void drop_collected_mounts(struct vfsmount *mnt)
LIST_HEAD(umount_list);
down_write(&namespace_sem);
br_write_lock(vfsmount_lock);
- umount_tree(mnt, 0, &umount_list);
+ umount_tree(real_mount(mnt), 0, &umount_list);
br_write_unlock(vfsmount_lock);
up_write(&namespace_sem);
release_mounts(&umount_list);
int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg,
struct vfsmount *root)
{
- struct vfsmount *mnt;
+ struct mount *mnt;
int res = f(root, arg);
if (res)
return res;
- list_for_each_entry(mnt, &root->mnt_list, mnt_list) {
- res = f(mnt, arg);
+ list_for_each_entry(mnt, &real_mount(root)->mnt_list, mnt_list) {
+ res = f(&mnt->mnt, arg);
if (res)
return res;
}
return 0;
}
-static void cleanup_group_ids(struct vfsmount *mnt, struct vfsmount *end)
+static void cleanup_group_ids(struct mount *mnt, struct mount *end)
{
- struct vfsmount *p;
+ struct mount *p;
for (p = mnt; p != end; p = next_mnt(p, mnt)) {
if (p->mnt_group_id && !IS_MNT_SHARED(p))
}
}
-static int invent_group_ids(struct vfsmount *mnt, bool recurse)
+static int invent_group_ids(struct mount *mnt, bool recurse)
{
- struct vfsmount *p;
+ struct mount *p;
for (p = mnt; p; p = recurse ? next_mnt(p, mnt) : NULL) {
if (!p->mnt_group_id && !IS_MNT_SHARED(p)) {
* Must be called without spinlocks held, since this function can sleep
* in allocations.
*/
-static int attach_recursive_mnt(struct vfsmount *source_mnt,
+static int attach_recursive_mnt(struct mount *source_mnt,
struct path *path, struct path *parent_path)
{
LIST_HEAD(tree_list);
- struct vfsmount *dest_mnt = path->mnt;
+ struct mount *dest_mnt = real_mount(path->mnt);
struct dentry *dest_dentry = path->dentry;
- struct vfsmount *child, *p;
+ struct mount *child, *p;
int err;
if (IS_MNT_SHARED(dest_mnt)) {
if (parent_path) {
detach_mnt(source_mnt, parent_path);
attach_mnt(source_mnt, path);
- touch_mnt_namespace(parent_path->mnt->mnt_ns);
+ touch_mnt_namespace(source_mnt->mnt_ns);
} else {
mnt_set_mountpoint(dest_mnt, dest_dentry, source_mnt);
commit_tree(source_mnt);
mutex_unlock(&path->dentry->d_inode->i_mutex);
}
-static int graft_tree(struct vfsmount *mnt, struct path *path)
+static int graft_tree(struct mount *mnt, struct path *path)
{
- if (mnt->mnt_sb->s_flags & MS_NOUSER)
+ if (mnt->mnt.mnt_sb->s_flags & MS_NOUSER)
return -EINVAL;
if (S_ISDIR(path->dentry->d_inode->i_mode) !=
- S_ISDIR(mnt->mnt_root->d_inode->i_mode))
+ S_ISDIR(mnt->mnt.mnt_root->d_inode->i_mode))
return -ENOTDIR;
if (d_unlinked(path->dentry))
*/
static int do_change_type(struct path *path, int flag)
{
- struct vfsmount *m, *mnt = path->mnt;
+ struct mount *m;
+ struct mount *mnt = real_mount(path->mnt);
int recurse = flag & MS_REC;
int type;
int err = 0;
{
LIST_HEAD(umount_list);
struct path old_path;
- struct vfsmount *mnt = NULL;
+ struct mount *mnt = NULL, *old;
int err = mount_is_safe(path);
if (err)
return err;
if (err)
goto out;
+ old = real_mount(old_path.mnt);
+
err = -EINVAL;
- if (IS_MNT_UNBINDABLE(old_path.mnt))
+ if (IS_MNT_UNBINDABLE(old))
goto out2;
- if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt))
+ if (!check_mnt(real_mount(path->mnt)) || !check_mnt(old))
goto out2;
err = -ENOMEM;
if (recurse)
- mnt = copy_tree(old_path.mnt, old_path.dentry, 0);
+ mnt = copy_tree(old, old_path.dentry, 0);
else
- mnt = clone_mnt(old_path.mnt, old_path.dentry, 0);
+ mnt = clone_mnt(old, old_path.dentry, 0);
if (!mnt)
goto out2;
return 0;
if (readonly_request)
- error = mnt_make_readonly(mnt);
+ error = mnt_make_readonly(real_mount(mnt));
else
- __mnt_unmake_readonly(mnt);
+ __mnt_unmake_readonly(real_mount(mnt));
return error;
}
{
int err;
struct super_block *sb = path->mnt->mnt_sb;
+ struct mount *mnt = real_mount(path->mnt);
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (!check_mnt(path->mnt))
+ if (!check_mnt(mnt))
return -EINVAL;
if (path->dentry != path->mnt->mnt_root)
err = do_remount_sb(sb, flags, data, 0);
if (!err) {
br_write_lock(vfsmount_lock);
- mnt_flags |= path->mnt->mnt_flags & MNT_PROPAGATION_MASK;
- path->mnt->mnt_flags = mnt_flags;
+ mnt_flags |= mnt->mnt.mnt_flags & MNT_PROPAGATION_MASK;
+ mnt->mnt.mnt_flags = mnt_flags;
br_write_unlock(vfsmount_lock);
}
up_write(&sb->s_umount);
if (!err) {
br_write_lock(vfsmount_lock);
- touch_mnt_namespace(path->mnt->mnt_ns);
+ touch_mnt_namespace(mnt->mnt_ns);
br_write_unlock(vfsmount_lock);
}
return err;
}
-static inline int tree_contains_unbindable(struct vfsmount *mnt)
+static inline int tree_contains_unbindable(struct mount *mnt)
{
- struct vfsmount *p;
+ struct mount *p;
for (p = mnt; p; p = next_mnt(p, mnt)) {
if (IS_MNT_UNBINDABLE(p))
return 1;
static int do_move_mount(struct path *path, char *old_name)
{
struct path old_path, parent_path;
- struct vfsmount *p;
+ struct mount *p;
+ struct mount *old;
int err = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (err < 0)
goto out;
+ old = real_mount(old_path.mnt);
+ p = real_mount(path->mnt);
+
err = -EINVAL;
- if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt))
+ if (!check_mnt(p) || !check_mnt(old))
goto out1;
if (d_unlinked(path->dentry))
if (old_path.dentry != old_path.mnt->mnt_root)
goto out1;
- if (old_path.mnt == old_path.mnt->mnt_parent)
+ if (!mnt_has_parent(old))
goto out1;
if (S_ISDIR(path->dentry->d_inode->i_mode) !=
/*
* Don't move a mount residing in a shared parent.
*/
- if (old_path.mnt->mnt_parent &&
- IS_MNT_SHARED(old_path.mnt->mnt_parent))
+ if (IS_MNT_SHARED(old->mnt_parent))
goto out1;
/*
* Don't move a mount tree containing unbindable mounts to a destination
* mount which is shared.
*/
- if (IS_MNT_SHARED(path->mnt) &&
- tree_contains_unbindable(old_path.mnt))
+ if (IS_MNT_SHARED(p) && tree_contains_unbindable(old))
goto out1;
err = -ELOOP;
- for (p = path->mnt; p->mnt_parent != p; p = p->mnt_parent)
- if (p == old_path.mnt)
+ for (; mnt_has_parent(p); p = p->mnt_parent)
+ if (p == old)
goto out1;
- err = attach_recursive_mnt(old_path.mnt, path, &parent_path);
+ err = attach_recursive_mnt(old, path, &parent_path);
if (err)
goto out1;
/* if the mount is moved, it should no longer be expire
* automatically */
- list_del_init(&old_path.mnt->mnt_expire);
+ list_del_init(&old->mnt_expire);
out1:
unlock_mount(path);
out:
return ERR_PTR(err);
}
-struct vfsmount *
+static struct vfsmount *
do_kern_mount(const char *fstype, int flags, const char *name, void *data)
{
struct file_system_type *type = get_fs_type(fstype);
put_filesystem(type);
return mnt;
}
-EXPORT_SYMBOL_GPL(do_kern_mount);
/*
* add a mount into a namespace's mount tree
*/
-static int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)
+static int do_add_mount(struct mount *newmnt, struct path *path, int mnt_flags)
{
int err;
return err;
err = -EINVAL;
- if (!(mnt_flags & MNT_SHRINKABLE) && !check_mnt(path->mnt))
+ if (!(mnt_flags & MNT_SHRINKABLE) && !check_mnt(real_mount(path->mnt)))
goto unlock;
/* Refuse the same filesystem on the same mount point */
err = -EBUSY;
- if (path->mnt->mnt_sb == newmnt->mnt_sb &&
+ if (path->mnt->mnt_sb == newmnt->mnt.mnt_sb &&
path->mnt->mnt_root == path->dentry)
goto unlock;
err = -EINVAL;
- if (S_ISLNK(newmnt->mnt_root->d_inode->i_mode))
+ if (S_ISLNK(newmnt->mnt.mnt_root->d_inode->i_mode))
goto unlock;
- newmnt->mnt_flags = mnt_flags;
+ newmnt->mnt.mnt_flags = mnt_flags;
err = graft_tree(newmnt, path);
unlock:
if (IS_ERR(mnt))
return PTR_ERR(mnt);
- err = do_add_mount(mnt, path, mnt_flags);
+ err = do_add_mount(real_mount(mnt), path, mnt_flags);
if (err)
mntput(mnt);
return err;
int finish_automount(struct vfsmount *m, struct path *path)
{
+ struct mount *mnt = real_mount(m);
int err;
/* The new mount record should have at least 2 refs to prevent it being
* expired before we get a chance to add it
*/
- BUG_ON(mnt_get_count(m) < 2);
+ BUG_ON(mnt_get_count(mnt) < 2);
if (m->mnt_sb == path->mnt->mnt_sb &&
m->mnt_root == path->dentry) {
goto fail;
}
- err = do_add_mount(m, path, path->mnt->mnt_flags | MNT_SHRINKABLE);
+ err = do_add_mount(mnt, path, path->mnt->mnt_flags | MNT_SHRINKABLE);
if (!err)
return 0;
fail:
/* remove m from any expiration list it may be on */
- if (!list_empty(&m->mnt_expire)) {
+ if (!list_empty(&mnt->mnt_expire)) {
down_write(&namespace_sem);
br_write_lock(vfsmount_lock);
- list_del_init(&m->mnt_expire);
+ list_del_init(&mnt->mnt_expire);
br_write_unlock(vfsmount_lock);
up_write(&namespace_sem);
}
down_write(&namespace_sem);
br_write_lock(vfsmount_lock);
- list_add_tail(&mnt->mnt_expire, expiry_list);
+ list_add_tail(&real_mount(mnt)->mnt_expire, expiry_list);
br_write_unlock(vfsmount_lock);
up_write(&namespace_sem);
*/
void mark_mounts_for_expiry(struct list_head *mounts)
{
- struct vfsmount *mnt, *next;
+ struct mount *mnt, *next;
LIST_HEAD(graveyard);
LIST_HEAD(umounts);
list_move(&mnt->mnt_expire, &graveyard);
}
while (!list_empty(&graveyard)) {
- mnt = list_first_entry(&graveyard, struct vfsmount, mnt_expire);
+ mnt = list_first_entry(&graveyard, struct mount, mnt_expire);
touch_mnt_namespace(mnt->mnt_ns);
umount_tree(mnt, 1, &umounts);
}
* search the list of submounts for a given mountpoint, and move any
* shrinkable submounts to the 'graveyard' list.
*/
-static int select_submounts(struct vfsmount *parent, struct list_head *graveyard)
+static int select_submounts(struct mount *parent, struct list_head *graveyard)
{
- struct vfsmount *this_parent = parent;
+ struct mount *this_parent = parent;
struct list_head *next;
int found = 0;
resume:
while (next != &this_parent->mnt_mounts) {
struct list_head *tmp = next;
- struct vfsmount *mnt = list_entry(tmp, struct vfsmount, mnt_child);
+ struct mount *mnt = list_entry(tmp, struct mount, mnt_child);
next = tmp->next;
- if (!(mnt->mnt_flags & MNT_SHRINKABLE))
+ if (!(mnt->mnt.mnt_flags & MNT_SHRINKABLE))
continue;
/*
* Descend a level if the d_mounts list is non-empty.
*
* vfsmount_lock must be held for write
*/
-static void shrink_submounts(struct vfsmount *mnt, struct list_head *umounts)
+static void shrink_submounts(struct mount *mnt, struct list_head *umounts)
{
LIST_HEAD(graveyard);
- struct vfsmount *m;
+ struct mount *m;
/* extract submounts of 'mountpoint' from the expiration list */
while (select_submounts(mnt, &graveyard)) {
while (!list_empty(&graveyard)) {
- m = list_first_entry(&graveyard, struct vfsmount,
+ m = list_first_entry(&graveyard, struct mount,
mnt_expire);
touch_mnt_namespace(m->mnt_ns);
umount_tree(m, 1, umounts);
void mnt_make_longterm(struct vfsmount *mnt)
{
- __mnt_make_longterm(mnt);
+ __mnt_make_longterm(real_mount(mnt));
}
-void mnt_make_shortterm(struct vfsmount *mnt)
+void mnt_make_shortterm(struct vfsmount *m)
{
#ifdef CONFIG_SMP
+ struct mount *mnt = real_mount(m);
if (atomic_add_unless(&mnt->mnt_longterm, -1, 1))
return;
br_write_lock(vfsmount_lock);
{
struct mnt_namespace *new_ns;
struct vfsmount *rootmnt = NULL, *pwdmnt = NULL;
- struct vfsmount *p, *q;
+ struct mount *p, *q;
+ struct mount *old = mnt_ns->root;
+ struct mount *new;
new_ns = alloc_mnt_ns();
if (IS_ERR(new_ns))
down_write(&namespace_sem);
/* First pass: copy the tree topology */
- new_ns->root = copy_tree(mnt_ns->root, mnt_ns->root->mnt_root,
- CL_COPY_ALL | CL_EXPIRE);
- if (!new_ns->root) {
+ new = copy_tree(old, old->mnt.mnt_root, CL_COPY_ALL | CL_EXPIRE);
+ if (!new) {
up_write(&namespace_sem);
kfree(new_ns);
return ERR_PTR(-ENOMEM);
}
+ new_ns->root = new;
br_write_lock(vfsmount_lock);
- list_add_tail(&new_ns->list, &new_ns->root->mnt_list);
+ list_add_tail(&new_ns->list, &new->mnt_list);
br_write_unlock(vfsmount_lock);
/*
* as belonging to new namespace. We have already acquired a private
* fs_struct, so tsk->fs->lock is not needed.
*/
- p = mnt_ns->root;
- q = new_ns->root;
+ p = old;
+ q = new;
while (p) {
q->mnt_ns = new_ns;
__mnt_make_longterm(q);
if (fs) {
- if (p == fs->root.mnt) {
- fs->root.mnt = mntget(q);
+ if (&p->mnt == fs->root.mnt) {
+ fs->root.mnt = mntget(&q->mnt);
__mnt_make_longterm(q);
- mnt_make_shortterm(p);
- rootmnt = p;
+ mnt_make_shortterm(&p->mnt);
+ rootmnt = &p->mnt;
}
- if (p == fs->pwd.mnt) {
- fs->pwd.mnt = mntget(q);
+ if (&p->mnt == fs->pwd.mnt) {
+ fs->pwd.mnt = mntget(&q->mnt);
__mnt_make_longterm(q);
- mnt_make_shortterm(p);
- pwdmnt = p;
+ mnt_make_shortterm(&p->mnt);
+ pwdmnt = &p->mnt;
}
}
- p = next_mnt(p, mnt_ns->root);
- q = next_mnt(q, new_ns->root);
+ p = next_mnt(p, old);
+ q = next_mnt(q, new);
}
up_write(&namespace_sem);
* create_mnt_ns - creates a private namespace and adds a root filesystem
* @mnt: pointer to the new root filesystem mountpoint
*/
-struct mnt_namespace *create_mnt_ns(struct vfsmount *mnt)
+static struct mnt_namespace *create_mnt_ns(struct vfsmount *m)
{
- struct mnt_namespace *new_ns;
-
- new_ns = alloc_mnt_ns();
+ struct mnt_namespace *new_ns = alloc_mnt_ns();
if (!IS_ERR(new_ns)) {
+ struct mount *mnt = real_mount(m);
mnt->mnt_ns = new_ns;
__mnt_make_longterm(mnt);
new_ns->root = mnt;
- list_add(&new_ns->list, &new_ns->root->mnt_list);
+ list_add(&new_ns->list, &mnt->mnt_list);
} else {
- mntput(mnt);
+ mntput(m);
}
return new_ns;
}
-EXPORT_SYMBOL(create_mnt_ns);
struct dentry *mount_subtree(struct vfsmount *mnt, const char *name)
{
return ret;
}
+/*
+ * Return true if path is reachable from root
+ *
+ * namespace_sem or vfsmount_lock is held
+ */
+bool is_path_reachable(struct mount *mnt, struct dentry *dentry,
+ const struct path *root)
+{
+ while (&mnt->mnt != root->mnt && mnt_has_parent(mnt)) {
+ dentry = mnt->mnt_mountpoint;
+ mnt = mnt->mnt_parent;
+ }
+ return &mnt->mnt == root->mnt && is_subdir(dentry, root->dentry);
+}
+
+int path_is_under(struct path *path1, struct path *path2)
+{
+ int res;
+ br_read_lock(vfsmount_lock);
+ res = is_path_reachable(real_mount(path1->mnt), path1->dentry, path2);
+ br_read_unlock(vfsmount_lock);
+ return res;
+}
+EXPORT_SYMBOL(path_is_under);
+
/*
* pivot_root Semantics:
* Moves the root file system of the current process to the directory put_old,
SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
const char __user *, put_old)
{
- struct vfsmount *tmp;
struct path new, old, parent_path, root_parent, root;
+ struct mount *new_mnt, *root_mnt;
int error;
if (!capable(CAP_SYS_ADMIN))
goto out3;
error = -EINVAL;
- if (IS_MNT_SHARED(old.mnt) ||
- IS_MNT_SHARED(new.mnt->mnt_parent) ||
- IS_MNT_SHARED(root.mnt->mnt_parent))
+ new_mnt = real_mount(new.mnt);
+ root_mnt = real_mount(root.mnt);
+ if (IS_MNT_SHARED(real_mount(old.mnt)) ||
+ IS_MNT_SHARED(new_mnt->mnt_parent) ||
+ IS_MNT_SHARED(root_mnt->mnt_parent))
goto out4;
- if (!check_mnt(root.mnt) || !check_mnt(new.mnt))
+ if (!check_mnt(root_mnt) || !check_mnt(new_mnt))
goto out4;
error = -ENOENT;
if (d_unlinked(new.dentry))
error = -EINVAL;
if (root.mnt->mnt_root != root.dentry)
goto out4; /* not a mountpoint */
- if (root.mnt->mnt_parent == root.mnt)
+ if (!mnt_has_parent(root_mnt))
goto out4; /* not attached */
if (new.mnt->mnt_root != new.dentry)
goto out4; /* not a mountpoint */
- if (new.mnt->mnt_parent == new.mnt)
+ if (!mnt_has_parent(new_mnt))
goto out4; /* not attached */
/* make sure we can reach put_old from new_root */
- tmp = old.mnt;
- if (tmp != new.mnt) {
- for (;;) {
- if (tmp->mnt_parent == tmp)
- goto out4; /* already mounted on put_old */
- if (tmp->mnt_parent == new.mnt)
- break;
- tmp = tmp->mnt_parent;
- }
- if (!is_subdir(tmp->mnt_mountpoint, new.dentry))
- goto out4;
- } else if (!is_subdir(old.dentry, new.dentry))
+ if (!is_path_reachable(real_mount(old.mnt), old.dentry, &new))
goto out4;
br_write_lock(vfsmount_lock);
- detach_mnt(new.mnt, &parent_path);
- detach_mnt(root.mnt, &root_parent);
+ detach_mnt(new_mnt, &parent_path);
+ detach_mnt(root_mnt, &root_parent);
/* mount old root on put_old */
- attach_mnt(root.mnt, &old);
+ attach_mnt(root_mnt, &old);
/* mount new_root on / */
- attach_mnt(new.mnt, &root_parent);
+ attach_mnt(new_mnt, &root_parent);
touch_mnt_namespace(current->nsproxy->mnt_ns);
br_write_unlock(vfsmount_lock);
chroot_fs_refs(&root, &new);
init_task.nsproxy->mnt_ns = ns;
get_mnt_ns(ns);
- root.mnt = ns->root;
- root.dentry = ns->root->mnt_root;
+ root.mnt = mnt;
+ root.dentry = mnt->mnt_root;
set_fs_pwd(current->fs, &root);
set_fs_root(current->fs, &root);
init_rwsem(&namespace_sem);
- mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct vfsmount),
+ mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct mount),
0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
mount_hashtable = (struct list_head *)__get_free_page(GFP_ATOMIC);
release_mounts(&umount_list);
kfree(ns);
}
-EXPORT_SYMBOL(put_mnt_ns);
struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
{
bool our_mnt(struct vfsmount *mnt)
{
- return check_mnt(mnt);
+ return check_mnt(real_mount(mnt));
}
projects / karo-tx-linux.git / blobdiff