This is a note to let you know that I've just added the patch titled mnt: Delay removal from the mount hash. to the 4.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mnt-delay-removal-from-the-mount-hash.patch and it can be found in the queue-4.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 411a938b5abc9cb126c41cccf5975ae464fe0f3e Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Date: Mon, 22 Dec 2014 19:12:07 -0600 Subject: mnt: Delay removal from the mount hash. From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> commit 411a938b5abc9cb126c41cccf5975ae464fe0f3e upstream. - Modify __lookup_mnt_hash_last to ignore mounts that have MNT_UMOUNTED set. - Don't remove mounts from the mount hash table in propogate_umount - Don't remove mounts from the mount hash table in umount_tree before the entire list of mounts to be umounted is selected. - Remove mounts from the mount hash table as the last thing that happens in the case where a mount has a parent in umount_tree. Mounts without parents are not hashed (by definition). This paves the way for delaying removal from the mount hash table even farther and fixing the MNT_LOCKED vs MNT_DETACH issue. Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/namespace.c | 13 ++++++++----- fs/pnode.c | 1 - 2 files changed, 8 insertions(+), 6 deletions(-) --- a/fs/namespace.c +++ b/fs/namespace.c @@ -632,14 +632,17 @@ struct mount *__lookup_mnt(struct vfsmou */ struct mount *__lookup_mnt_last(struct vfsmount *mnt, struct dentry *dentry) { - struct mount *p, *res; - res = p = __lookup_mnt(mnt, dentry); + struct mount *p, *res = NULL; + p = __lookup_mnt(mnt, dentry); if (!p) goto out; + if (!(p->mnt.mnt_flags & MNT_UMOUNT)) + res = p; hlist_for_each_entry_continue(p, mnt_hash) { if (&p->mnt_parent->mnt != mnt || p->mnt_mountpoint != dentry) break; - res = p; + if (!(p->mnt.mnt_flags & MNT_UMOUNT)) + res = p; } out: return res; @@ -1338,9 +1341,8 @@ static void umount_tree(struct mount *mn list_move(&p->mnt_list, &tmp_list); } - /* Hide the mounts from lookup_mnt and mnt_mounts */ + /* Hide the mounts from mnt_mounts */ list_for_each_entry(p, &tmp_list, mnt_list) { - hlist_del_init_rcu(&p->mnt_hash); list_del_init(&p->mnt_child); } @@ -1367,6 +1369,7 @@ static void umount_tree(struct mount *mn p->mnt_mountpoint = p->mnt.mnt_root; p->mnt_parent = p; p->mnt_mp = NULL; + hlist_del_init_rcu(&p->mnt_hash); } change_mnt_propagation(p, MS_PRIVATE); } --- a/fs/pnode.c +++ b/fs/pnode.c @@ -383,7 +383,6 @@ static void __propagate_umount(struct mo */ if (child && list_empty(&child->mnt_mounts)) { list_del_init(&child->mnt_child); - hlist_del_init_rcu(&child->mnt_hash); child->mnt.mnt_flags |= MNT_UMOUNT; list_move_tail(&child->mnt_list, &mnt->mnt_list); } Patches currently in stable-queue which might be from ebiederm@xxxxxxxxxxxx are queue-4.0/mnt-don-t-propagate-umounts-in-__detach_mounts.patch queue-4.0/mnt-add-mnt_umount-flag.patch queue-4.0/mnt-honor-mnt_locked-when-detaching-mounts.patch queue-4.0/mnt-delay-removal-from-the-mount-hash.patch queue-4.0/mnt-on-an-unmount-propagate-clearing-of-mnt_locked.patch queue-4.0/mnt-don-t-propagate-unmounts-to-locked-mounts.patch queue-4.0/mnt-factor-out-unhash_mnt-from-detach_mnt-and-umount_tree.patch queue-4.0/mnt-factor-umount_mnt-from-umount_tree.patch queue-4.0/mnt-fix-the-error-check-in-__detach_mounts.patch queue-4.0/mnt-update-detach_mounts-to-leave-mounts-connected.patch queue-4.0/mnt-improve-the-umount_tree-flags.patch queue-4.0/mnt-in-umount_tree-reuse-mnt_list-instead-of-mnt_hash.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html