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Diffstat (limited to 'ipc/namespace.c')
-rw-r--r--ipc/namespace.c22
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
*