[PATCH 06/23] net, ceph: convert ceph_pagelist.refcnt from atomic_t to refcount_t
From: Elena Reshetova <elena.reshetova@intel.com>
Date: 2017-03-17 12:12:05
Also in:
ceph-devel, linux-hams, linux-nfs, linux-rdma, linux-sctp, lkml
Subsystem:
ceph common code (libceph), ceph distributed file system client (ceph), filesystems (vfs and infrastructure), the rest · Maintainers:
Ilya Dryomov, Alex Markuze, Viacheslav Dubeyko, Alexander Viro, Christian Brauner, Linus Torvalds
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <redacted> Signed-off-by: Kees Cook <redacted> Signed-off-by: David Windsor <redacted> --- fs/ceph/mds_client.c | 2 +- include/linux/ceph/pagelist.h | 6 +++--- net/ceph/pagelist.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index c681762..7b38e6c 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c@@ -1991,7 +1991,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc, if (req->r_pagelist) { struct ceph_pagelist *pagelist = req->r_pagelist; - atomic_inc(&pagelist->refcnt); + refcount_inc(&pagelist->refcnt); ceph_msg_data_add_pagelist(msg, pagelist); msg->hdr.data_len = cpu_to_le32(pagelist->length); } else {
diff --git a/include/linux/ceph/pagelist.h b/include/linux/ceph/pagelist.h
index 13d71fe..75a7db2 100644
--- a/include/linux/ceph/pagelist.h
+++ b/include/linux/ceph/pagelist.h@@ -2,7 +2,7 @@ #define __FS_CEPH_PAGELIST_H #include <asm/byteorder.h> -#include <linux/atomic.h> +#include <linux/refcount.h> #include <linux/list.h> #include <linux/types.h>
@@ -13,7 +13,7 @@ struct ceph_pagelist { size_t room; struct list_head free_list; size_t num_pages_free; - atomic_t refcnt; + refcount_t refcnt; }; struct ceph_pagelist_cursor {
@@ -30,7 +30,7 @@ static inline void ceph_pagelist_init(struct ceph_pagelist *pl) pl->room = 0; INIT_LIST_HEAD(&pl->free_list); pl->num_pages_free = 0; - atomic_set(&pl->refcnt, 1); + refcount_set(&pl->refcnt, 1); } extern void ceph_pagelist_release(struct ceph_pagelist *pl);
diff --git a/net/ceph/pagelist.c b/net/ceph/pagelist.c
index 6864007..ce09f73 100644
--- a/net/ceph/pagelist.c
+++ b/net/ceph/pagelist.c@@ -16,7 +16,7 @@ static void ceph_pagelist_unmap_tail(struct ceph_pagelist *pl) void ceph_pagelist_release(struct ceph_pagelist *pl) { - if (!atomic_dec_and_test(&pl->refcnt)) + if (!refcount_dec_and_test(&pl->refcnt)) return; ceph_pagelist_unmap_tail(pl); while (!list_empty(&pl->head)) {
--
2.7.4