diff options
| -rw-r--r-- | fs/namespace.c | 84 |
1 files changed, 51 insertions, 33 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index dfeeab964e84..c2ffa0f349fd 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -394,32 +394,45 @@ int may_umount(struct vfsmount *mnt) EXPORT_SYMBOL(may_umount); -static void umount_tree(struct vfsmount *mnt) +static void release_mounts(struct list_head *head) +{ + struct vfsmount *mnt; + while(!list_empty(head)) { + mnt = list_entry(head->next, struct vfsmount, mnt_hash); + list_del_init(&mnt->mnt_hash); + if (mnt->mnt_parent != mnt) { + struct dentry *dentry; + struct vfsmount *m; + spin_lock(&vfsmount_lock); + dentry = mnt->mnt_mountpoint; + m = mnt->mnt_parent; + mnt->mnt_mountpoint = mnt->mnt_root; + mnt->mnt_parent = mnt; + spin_unlock(&vfsmount_lock); + dput(dentry); + mntput(m); + } + mntput(mnt); + } +} + +static 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); - __touch_namespace(p->mnt_namespace); - p->mnt_namespace = NULL; + list_del(&p->mnt_hash); + list_add(&p->mnt_hash, kill); } - while (!list_empty(&kill)) { - mnt = list_entry(kill.next, struct vfsmount, mnt_list); - list_del_init(&mnt->mnt_list); - list_del_init(&mnt->mnt_expire); - if (mnt->mnt_parent == mnt) { - spin_unlock(&vfsmount_lock); - } else { - struct nameidata old_nd; - detach_mnt(mnt, &old_nd); - spin_unlock(&vfsmount_lock); - path_release(&old_nd); - } - mntput(mnt); - spin_lock(&vfsmount_lock); + list_for_each_entry(p, kill, mnt_hash) { + list_del_init(&p->mnt_expire); + list_del_init(&p->mnt_list); + __touch_namespace(p->mnt_namespace); + p->mnt_namespace = NULL; + list_del_init(&p->mnt_child); + if (p->mnt_parent != p) + mnt->mnt_mountpoint->d_mounted--; } } @@ -427,6 +440,7 @@ static int do_umount(struct vfsmount *mnt, int flags) { struct super_block *sb = mnt->mnt_sb; int retval; + LIST_HEAD(umount_list); retval = security_sb_umount(mnt, flags); if (retval) @@ -497,13 +511,14 @@ static int do_umount(struct vfsmount *mnt, int flags) retval = -EBUSY; if (atomic_read(&mnt->mnt_count) == 2 || flags & MNT_DETACH) { if (!list_empty(&mnt->mnt_list)) - umount_tree(mnt); + umount_tree(mnt, &umount_list); retval = 0; } spin_unlock(&vfsmount_lock); if (retval) security_sb_umount_busy(mnt); up_write(¤t->namespace->sem); + release_mounts(&umount_list); return retval; } @@ -616,9 +631,11 @@ static struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry) return res; Enomem: if (res) { + LIST_HEAD(umount_list); spin_lock(&vfsmount_lock); - umount_tree(res); + umount_tree(res, &umount_list); spin_unlock(&vfsmount_lock); + release_mounts(&umount_list); } return NULL; } @@ -698,9 +715,11 @@ static int do_loopback(struct nameidata *nd, char *old_name, int recurse) err = graft_tree(mnt, nd); if (err) { + LIST_HEAD(umount_list); spin_lock(&vfsmount_lock); - umount_tree(mnt); + umount_tree(mnt, &umount_list); spin_unlock(&vfsmount_lock); + release_mounts(&umount_list); } out: @@ -875,7 +894,8 @@ unlock: EXPORT_SYMBOL_GPL(do_add_mount); -static void expire_mount(struct vfsmount *mnt, struct list_head *mounts) +static void expire_mount(struct vfsmount *mnt, struct list_head *mounts, + struct list_head *umounts) { spin_lock(&vfsmount_lock); @@ -893,16 +913,12 @@ static void expire_mount(struct vfsmount *mnt, struct list_head *mounts) * contributed by the vfsmount parent and the mntget above */ if (atomic_read(&mnt->mnt_count) == 2) { - struct nameidata old_nd; - /* delete from the namespace */ touch_namespace(mnt->mnt_namespace); list_del_init(&mnt->mnt_list); mnt->mnt_namespace = NULL; - detach_mnt(mnt, &old_nd); + umount_tree(mnt, umounts); spin_unlock(&vfsmount_lock); - path_release(&old_nd); - mntput(mnt); } else { /* * Someone brought it back to life whilst we didn't have any @@ -951,6 +967,7 @@ void mark_mounts_for_expiry(struct list_head *mounts) * - 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); @@ -963,12 +980,11 @@ void mark_mounts_for_expiry(struct list_head *mounts) spin_unlock(&vfsmount_lock); down_write(&namespace->sem); - expire_mount(mnt, mounts); + expire_mount(mnt, mounts, &umounts); up_write(&namespace->sem); - + release_mounts(&umounts); mntput(mnt); put_namespace(namespace); - spin_lock(&vfsmount_lock); } @@ -1508,12 +1524,14 @@ void __init mnt_init(unsigned long mempages) void __put_namespace(struct namespace *namespace) { struct vfsmount *root = namespace->root; + LIST_HEAD(umount_list); namespace->root = NULL; spin_unlock(&vfsmount_lock); down_write(&namespace->sem); spin_lock(&vfsmount_lock); - umount_tree(root); + umount_tree(root, &umount_list); spin_unlock(&vfsmount_lock); up_write(&namespace->sem); + release_mounts(&umount_list); kfree(namespace); } |