diff options
Diffstat (limited to 'ipc')
| -rw-r--r-- | ipc/namespace.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/ipc/namespace.c b/ipc/namespace.c index 8316ea585733..a26860a41dac 100644 --- a/ipc/namespace.c +++ b/ipc/namespace.c @@ -19,6 +19,12 @@ #include "util.h" +/* + * The work queue is used to avoid the cost of synchronize_rcu in kern_unmount. + */ +static void free_ipc(struct work_struct *unused); +static DECLARE_WORK(free_ipc_work, free_ipc); + static struct ucounts *inc_ipc_namespaces(struct user_namespace *ns) { return inc_ucount(ns, current_euid(), UCOUNT_IPC_NAMESPACES); @@ -37,9 +43,18 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns, int err; err = -ENOSPC; + again: ucounts = inc_ipc_namespaces(user_ns); - if (!ucounts) + if (!ucounts) { + /* + * IPC namespaces are freed asynchronously, by free_ipc_work. + * If frees were pending, flush_work will wait, and + * return true. Fail the allocation if no frees are pending. + */ + if (flush_work(&free_ipc_work)) + goto again; goto fail; + } err = -ENOMEM; ns = kzalloc(sizeof(struct ipc_namespace), GFP_KERNEL_ACCOUNT); @@ -158,11 +173,6 @@ static void free_ipc(struct work_struct *unused) } /* - * The work queue is used to avoid the cost of synchronize_rcu in kern_unmount. - */ -static DECLARE_WORK(free_ipc_work, free_ipc); - -/* * put_ipc_ns - drop a reference to an ipc namespace. * @ns: the namespace to put * |