Add idr struct and the mutex lock corresponding to
this struct to pid_namespace struct. Use IDR API for implementing
create_pid_namespace. The only change in the function is that instead of
allocating a bitmap, now idr_init is used to initialise the radix tree
associated with this namespace. This tree will be then used by
alloc_pid, free_pid and pid lookup functions to perform their respective
tasks.
Signed-off-by: Gargi Sharma <gs051095@xxxxxxxxx>
---
include/linux/pid_namespace.h | 3 ++-
kernel/pid_namespace.c | 20 +++++---------------
2 files changed, 7 insertions(+), 16 deletions(-)
diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
index b089791..88cda3f 100644
--- a/include/linux/pid_namespace.h
+++ b/include/linux/pid_namespace.h
@@ -29,7 +29,8 @@ enum { /* definitions for pid_namespace's hide_pid field */
struct pid_namespace {
struct kref kref;
- struct pidmap pidmap[PIDMAP_ENTRIES];
+ struct idr *idr;
+ struct mutex idr_mutex_lock;
struct rcu_head rcu;
int last_pid;
unsigned int nr_hashed;
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 32c4645..fa994d4 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -98,7 +98,6 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns
struct pid_namespace *ns;
unsigned int level = parent_pid_ns->level + 1;
struct ucounts *ucounts;
- int i;
int err;
err = -ENOSPC;
@@ -113,17 +112,15 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns
if (ns == NULL)
goto out_dec;
- ns->pidmap[0].page = kzalloc(PAGE_SIZE, GFP_KERNEL);
- if (!ns->pidmap[0].page)
- goto out_free;
+ idr_init(ns->idr);
ns->pid_cachep = create_pid_cachep(level + 1);
if (ns->pid_cachep == NULL)
- goto out_free_map;
+ goto out_free_idr;
err = ns_alloc_inum(&ns->ns);
if (err)
- goto out_free_map;
+ goto out_free_idr;
ns->ns.ops = &pidns_operations;
kref_init(&ns->kref);
@@ -134,17 +131,10 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns
ns->nr_hashed = PIDNS_HASH_ADDING;
INIT_WORK(&ns->proc_work, proc_cleanup_work);
- set_bit(0, ns->pidmap[0].page);
- atomic_set(&ns->pidmap[0].nr_free, BITS_PER_PAGE - 1);
-
- for (i = 1; i < PIDMAP_ENTRIES; i++)
- atomic_set(&ns->pidmap[i].nr_free, BITS_PER_PAGE);
-
return ns;
-out_free_map:
- kfree(ns->pidmap[0].page);
-out_free:
+out_free_idr:
+ idr_destroy(ns->idr);
kmem_cache_free(pid_ns_cachep, ns);
out_dec:
dec_pid_namespaces(ucounts);
--
2.7.4
--
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