We've got several cases when ploop could not be unmounted resulting in -EBUSY. Sometimes we could find what holds it sometimes not, so let's introduce the global list of mount namespaces: it will make it easier to debug such cases.
https://jira.sw.ru/browse/PSBM-80869 Signed-off-by: Konstantin Khorenko <khore...@virtuozzo.com> Changes: v2: move sem lock/unlock inside free_mnt_ns() to fix calling copy_mnt_ns() without semaphore taken. --- fs/mount.h | 1 + fs/namespace.c | 11 +++++++++++ 2 files changed, 12 insertions(+) diff --git a/fs/mount.h b/fs/mount.h index f3f39baf9a06..0c4448dbe5d1 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -16,6 +16,7 @@ struct mnt_namespace { u64 event; RH_KABI_EXTEND(unsigned int mounts) /* # of mounts in the namespace */ RH_KABI_EXTEND(unsigned int pending_mounts) + struct list_head mntns_list; }; struct mnt_pcp { diff --git a/fs/namespace.c b/fs/namespace.c index 377ba4f36639..e3b6fb36ea13 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3125,6 +3125,10 @@ static void free_mnt_ns(struct mnt_namespace *ns) proc_free_inum(ns->proc_inum); dec_mnt_namespaces(ns->ucounts); put_user_ns(ns->user_ns); + + namespace_lock(); + list_del(&ns->mntns_list); + namespace_unlock(); kfree(ns); } @@ -3136,6 +3140,7 @@ static void free_mnt_ns(struct mnt_namespace *ns) * is effectively never, so we can ignore the possibility. */ static atomic64_t mnt_ns_seq = ATOMIC64_INIT(1); +static LIST_HEAD(all_mntns_list); /* protected by namespace_sem */ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns) { @@ -3162,6 +3167,7 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns) atomic_set(&new_ns->count, 1); new_ns->root = NULL; INIT_LIST_HEAD(&new_ns->list); + INIT_LIST_HEAD(&new_ns->mntns_list); init_waitqueue_head(&new_ns->poll); new_ns->event = 0; new_ns->user_ns = get_user_ns(user_ns); @@ -3199,6 +3205,8 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns, return new_ns; namespace_lock(); + list_add_tail(&new_ns->mntns_list, &all_mntns_list); + /* First pass: copy the tree topology */ copy_flags = CL_COPY_UNBINDABLE | CL_EXPIRE; if (user_ns != ns->user_ns) @@ -3262,6 +3270,9 @@ static struct mnt_namespace *create_mnt_ns(struct vfsmount *m) new_ns->root = mnt; new_ns->mounts++; list_add(&mnt->mnt_list, &new_ns->list); + namespace_lock(); + list_add_tail(&new_ns->mntns_list, &all_mntns_list); + namespace_unlock(); } else { mntput(m); } -- 2.15.1 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
