* Heavily rewritten.
*/
-#include <linux/config.h>
#include <linux/syscalls.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/acct.h>
#include <linux/capability.h>
#include <linux/module.h>
+#include <linux/sysfs.h>
#include <linux/seq_file.h>
#include <linux/namespace.h>
#include <linux/namei.h>
extern int __init init_rootfs(void);
-#ifdef CONFIG_SYSFS
-extern int __init sysfs_init(void);
-#else
-static inline int sysfs_init(void)
-{
- return 0;
-}
-#endif
-
/* spinlock for vfsmount related operations, inplace of dcache_lock */
__cacheline_aligned_in_smp DEFINE_SPINLOCK(vfsmount_lock);
return mnt;
}
+int simple_set_mnt(struct vfsmount *mnt, struct super_block *sb)
+{
+ mnt->mnt_sb = sb;
+ mnt->mnt_root = dget(sb->s_root);
+ return 0;
+}
+
+EXPORT_SYMBOL(simple_set_mnt);
+
void free_vfsmnt(struct vfsmount *mnt)
{
kfree(mnt->mnt_devname);
{
struct vfsmount *p;
- for (p = mnt; p; p = next_mnt(p, mnt)) {
- list_del(&p->mnt_hash);
- list_add(&p->mnt_hash, kill);
- }
+ for (p = mnt; p; p = next_mnt(p, mnt))
+ list_move(&p->mnt_hash, kill);
if (propagate)
propagate_umount(kill);
*/
lock_kernel();
- if ((flags & MNT_FORCE) && sb->s_op->umount_begin)
- sb->s_op->umount_begin(sb);
+ if (sb->s_op->umount_begin)
+ sb->s_op->umount_begin(mnt, flags);
unlock_kernel();
/*
/*
* do loopback mount.
*/
-static int do_loopback(struct nameidata *nd, char *old_name, unsigned long flags, int mnt_flags)
+static int do_loopback(struct nameidata *nd, char *old_name, int recurse)
{
struct nameidata old_nd;
struct vfsmount *mnt = NULL;
- int recurse = flags & MS_REC;
int err = mount_is_safe(nd);
-
if (err)
return err;
if (!old_name || !*old_name)
spin_unlock(&vfsmount_lock);
release_mounts(&umount_list);
}
- mnt->mnt_flags = mnt_flags;
out:
up_write(&namespace_sem);
}
}
+/*
+ * 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
+ */
+static void expire_mount_list(struct list_head *graveyard, struct list_head *mounts)
+{
+ struct namespace *namespace;
+ struct vfsmount *mnt;
+
+ while (!list_empty(graveyard)) {
+ LIST_HEAD(umounts);
+ mnt = list_entry(graveyard->next, struct vfsmount, mnt_expire);
+ list_del_init(&mnt->mnt_expire);
+
+ /* don't do anything if the namespace is dead - all the
+ * vfsmounts from it are going away anyway */
+ namespace = mnt->mnt_namespace;
+ if (!namespace || !namespace->root)
+ continue;
+ get_namespace(namespace);
+
+ spin_unlock(&vfsmount_lock);
+ down_write(&namespace_sem);
+ expire_mount(mnt, mounts, &umounts);
+ up_write(&namespace_sem);
+ release_mounts(&umounts);
+ mntput(mnt);
+ put_namespace(namespace);
+ spin_lock(&vfsmount_lock);
+ }
+}
+
/*
* 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
*/
void mark_mounts_for_expiry(struct list_head *mounts)
{
- struct namespace *namespace;
struct vfsmount *mnt, *next;
LIST_HEAD(graveyard);
list_move(&mnt->mnt_expire, &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)) {
- LIST_HEAD(umounts);
- mnt = list_entry(graveyard.next, struct vfsmount, mnt_expire);
- list_del_init(&mnt->mnt_expire);
+ expire_mount_list(&graveyard, mounts);
- /* don't do anything if the namespace is dead - all the
- * vfsmounts from it are going away anyway */
- namespace = mnt->mnt_namespace;
- if (!namespace || !namespace->root)
+ spin_unlock(&vfsmount_lock);
+}
+
+EXPORT_SYMBOL_GPL(mark_mounts_for_expiry);
+
+/*
+ * Ripoff of 'select_parent()'
+ *
+ * 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)
+{
+ struct vfsmount *this_parent = parent;
+ struct list_head *next;
+ int found = 0;
+
+repeat:
+ next = this_parent->mnt_mounts.next;
+resume:
+ while (next != &this_parent->mnt_mounts) {
+ struct list_head *tmp = next;
+ struct vfsmount *mnt = list_entry(tmp, struct vfsmount, mnt_child);
+
+ next = tmp->next;
+ if (!(mnt->mnt_flags & MNT_SHRINKABLE))
continue;
- get_namespace(namespace);
+ /*
+ * Descend a level if the d_mounts list is non-empty.
+ */
+ if (!list_empty(&mnt->mnt_mounts)) {
+ this_parent = mnt;
+ goto repeat;
+ }
- spin_unlock(&vfsmount_lock);
- down_write(&namespace_sem);
- expire_mount(mnt, mounts, &umounts);
- up_write(&namespace_sem);
- release_mounts(&umounts);
- mntput(mnt);
- put_namespace(namespace);
- spin_lock(&vfsmount_lock);
+ if (!propagate_mount_busy(mnt, 1)) {
+ mntget(mnt);
+ list_move_tail(&mnt->mnt_expire, graveyard);
+ found++;
+ }
}
+ /*
+ * All done at this level ... ascend and resume the search
+ */
+ if (this_parent != parent) {
+ next = this_parent->mnt_child.next;
+ this_parent = this_parent->mnt_parent;
+ goto resume;
+ }
+ return found;
+}
+
+/*
+ * process a list of expirable mountpoints with the intent of discarding any
+ * submounts of a specific parent mountpoint
+ */
+void shrink_submounts(struct vfsmount *mountpoint, struct list_head *mounts)
+{
+ LIST_HEAD(graveyard);
+ int found;
+
+ spin_lock(&vfsmount_lock);
+
+ /* extract submounts of 'mountpoint' from the expiration list */
+ while ((found = select_submounts(mountpoint, &graveyard)) != 0)
+ expire_mount_list(&graveyard, mounts);
spin_unlock(&vfsmount_lock);
}
-EXPORT_SYMBOL_GPL(mark_mounts_for_expiry);
+EXPORT_SYMBOL_GPL(shrink_submounts);
/*
* Some copy_from_user() implementations do not return the exact number of
retval = do_remount(&nd, flags & ~MS_REMOUNT, mnt_flags,
data_page);
else if (flags & MS_BIND)
- retval = do_loopback(&nd, dev_name, flags, mnt_flags);
+ retval = do_loopback(&nd, dev_name, flags & MS_REC);
else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE))
retval = do_change_type(&nd, flags);
else if (flags & MS_MOVE)
git.openpandora.org / pandora-kernel.git / blobdiff