Unverified Commit 1f84344c authored by Christian Brauner's avatar Christian Brauner
Browse files

Merge patch series "ns: rework reference counting" 

Christian Brauner <brauner@kernel.org> says:

Stop open accesses to the reference counts and cargo-culting the same
code in all namespace. Use a set of dedicated helpers and make the
actual count private.

* patches from https://lore.kernel.org/20250918-work-namespace-ns_ref-v1-0-1b0a98ee041e@kernel.org

:
  ns: rename to __ns_ref
  nsfs: port to ns_ref_*() helpers
  net: port to ns_ref_*() helpers
  uts: port to ns_ref_*() helpers
  ipv4: use check_net()
  net: use check_net()
  net-sysfs: use check_net()
  user: port to ns_ref_*() helpers
  time: port to ns_ref_*() helpers
  pid: port to ns_ref_*() helpers
  ipc: port to ns_ref_*() helpers
  cgroup: port to ns_ref_*() helpers
  mnt: port to ns_ref_*() helpers
  ns: add reference count helpers

Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parents bb57289f 024596a4

fs/mount.h

+1 −1
Original line number Diff line number Diff line
@@ -143,7 +143,7 @@ static inline void detach_mounts(struct dentry *dentry) 


static inline void get_mnt_ns(struct mnt_namespace *ns)

{

	refcount_inc(&ns->ns.count);

	ns_ref_inc(ns);

}



extern seqlock_t mount_lock;

fs/namespace.c

+3 −3
Original line number Diff line number Diff line
@@ -2110,7 +2110,7 @@ struct mnt_namespace *get_sequential_mnt_ns(struct mnt_namespace *mntns, bool pr 
		 * the mount namespace and it might already be on its

		 * deathbed.

		 */

		if (!refcount_inc_not_zero(&mntns->ns.count))

		if (!ns_ref_get(mntns))

			continue;



		return mntns;
@@ -6015,7 +6015,7 @@ struct mnt_namespace init_mnt_ns = { 
	.ns.inum	= PROC_MNT_INIT_INO,

	.ns.ops		= &mntns_operations,

	.user_ns	= &init_user_ns,

	.ns.count	= REFCOUNT_INIT(1),

	.ns.__ns_ref	= REFCOUNT_INIT(1),

	.passive	= REFCOUNT_INIT(1),

	.mounts		= RB_ROOT,

	.poll		= __WAIT_QUEUE_HEAD_INITIALIZER(init_mnt_ns.poll),
@@ -6084,7 +6084,7 @@ void __init mnt_init(void) 


void put_mnt_ns(struct mnt_namespace *ns)

{

	if (!refcount_dec_and_test(&ns->ns.count))

	if (!ns_ref_put(ns))

		return;

	namespace_lock();

	emptied_ns = ns;

fs/nsfs.c

+1 −1
Original line number Diff line number Diff line
@@ -492,7 +492,7 @@ static struct dentry *nsfs_fh_to_dentry(struct super_block *sb, struct fid *fh, 
		VFS_WARN_ON_ONCE(ns->ops->type != fid->ns_type);

		VFS_WARN_ON_ONCE(ns->inum != fid->ns_inum);



		if (!refcount_inc_not_zero(&ns->count))

		if (!__ns_ref_get(ns))

			return NULL;

	}

include/linux/cgroup_namespace.h

+2 −2
Original line number Diff line number Diff line
@@ -29,12 +29,12 @@ int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen, 


static inline void get_cgroup_ns(struct cgroup_namespace *ns)

{

	refcount_inc(&ns->ns.count);

	ns_ref_inc(ns);

}



static inline void put_cgroup_ns(struct cgroup_namespace *ns)

{

	if (refcount_dec_and_test(&ns->ns.count))

	if (ns_ref_put(ns))

		free_cgroup_ns(ns);

}

include/linux/ipc_namespace.h

+2 −2
Original line number Diff line number Diff line
@@ -140,14 +140,14 @@ extern struct ipc_namespace *copy_ipcs(unsigned long flags, 
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)

{

	if (ns)

		refcount_inc(&ns->ns.count);

		ns_ref_inc(ns);

	return ns;

}



static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)

{

	if (ns) {

		if (refcount_inc_not_zero(&ns->ns.count))

		if (ns_ref_get(ns))

			return ns;

	}