diff options
| -rw-r--r-- | fs/namespace.c | 105 |
1 files changed, 24 insertions, 81 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index c175218ebae1..1c78917ec930 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1210,75 +1210,6 @@ unlock: EXPORT_SYMBOL_GPL(do_add_mount); -static void expire_mount(struct vfsmount *mnt, struct list_head *mounts, - struct list_head *umounts) -{ - spin_lock(&vfsmount_lock); - - /* - * Check if mount is still attached, if not, let whoever holds it deal - * with the sucker - */ - if (mnt->mnt_parent == mnt) { - spin_unlock(&vfsmount_lock); - return; - } - - /* - * Check that it is still dead: the count should now be 2 - as - * contributed by the vfsmount parent and the mntget above - */ - if (!propagate_mount_busy(mnt, 2)) { - /* delete from the namespace */ - touch_mnt_namespace(mnt->mnt_ns); - list_del_init(&mnt->mnt_list); - mnt->mnt_ns = NULL; - umount_tree(mnt, 1, umounts); - spin_unlock(&vfsmount_lock); - } 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_expire, mounts); - spin_unlock(&vfsmount_lock); - } -} - -/* - * 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 mnt_namespace *ns; - struct vfsmount *mnt; - - while (!list_empty(graveyard)) { - LIST_HEAD(umounts); - mnt = list_first_entry(graveyard, 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 */ - ns = mnt->mnt_ns; - if (!ns || !ns->root) - continue; - get_mnt_ns(ns); - - spin_unlock(&vfsmount_lock); - down_write(&namespace_sem); - expire_mount(mnt, mounts, &umounts); - up_write(&namespace_sem); - release_mounts(&umounts); - mntput(mnt); - put_mnt_ns(ns); - 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 @@ -1288,10 +1219,12 @@ void mark_mounts_for_expiry(struct list_head *mounts) { struct vfsmount *mnt, *next; LIST_HEAD(graveyard); + LIST_HEAD(umounts); if (list_empty(mounts)) return; + down_write(&namespace_sem); spin_lock(&vfsmount_lock); /* extract from the expiration list every vfsmount that matches the @@ -1302,16 +1235,19 @@ void mark_mounts_for_expiry(struct list_head *mounts) */ list_for_each_entry_safe(mnt, next, mounts, mnt_expire) { if (!xchg(&mnt->mnt_expiry_mark, 1) || - atomic_read(&mnt->mnt_count) != 1) + propagate_mount_busy(mnt, 1)) continue; - - mntget(mnt); list_move(&mnt->mnt_expire, &graveyard); } - - expire_mount_list(&graveyard, mounts); - + while (!list_empty(&graveyard)) { + mnt = list_first_entry(&graveyard, struct vfsmount, mnt_expire); + touch_mnt_namespace(mnt->mnt_ns); + umount_tree(mnt, 1, &umounts); + } spin_unlock(&vfsmount_lock); + up_write(&namespace_sem); + + release_mounts(&umounts); } EXPORT_SYMBOL_GPL(mark_mounts_for_expiry); @@ -1347,7 +1283,6 @@ resume: } if (!propagate_mount_busy(mnt, 1)) { - mntget(mnt); list_move_tail(&mnt->mnt_expire, graveyard); found++; } @@ -1370,15 +1305,23 @@ resume: void shrink_submounts(struct vfsmount *mountpoint, struct list_head *mounts) { LIST_HEAD(graveyard); - int found; + LIST_HEAD(umounts); + struct vfsmount *mnt; + down_write(&namespace_sem); spin_lock(&vfsmount_lock); - /* extract submounts of 'mountpoint' from the expiration list */ - while ((found = select_submounts(mountpoint, &graveyard)) != 0) - expire_mount_list(&graveyard, mounts); - + while (select_submounts(mountpoint, &graveyard)) { + while (!list_empty(&graveyard)) { + mnt = list_first_entry(&graveyard, struct vfsmount, + mnt_expire); + touch_mnt_namespace(mnt->mnt_ns); + umount_tree(mnt, 1, &umounts); + } + } spin_unlock(&vfsmount_lock); + up_write(&namespace_sem); + release_mounts(&umounts); } EXPORT_SYMBOL_GPL(shrink_submounts); |