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authorYan, Zheng <zyan@redhat.com>2017-09-11 12:10:08 +0800
committerIlya Dryomov <idryomov@gmail.com>2017-09-19 21:04:52 +0200
commit717e6f2893eb35ce6728c3cacdc297b78d371b31 (patch)
treefa76387b54e5903ff8fba0f5cfdebc58e24b125a
parent29a0cfbf91ba997591535a4f7246835ce8328141 (diff)
ceph: avoid panic in create_session_open_msg() if utsname() returns NULL
utsname() can return NULL while process is exiting. Kernel releases file locks during process exits. We send request to mds when releasing file lock. So it's possible that we open mds session while process is exiting. utsname() is called in create_session_open_msg(). Link: http://tracker.ceph.com/issues/21275 Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> [idryomov@gmail.com: drop utsname.h include from mds_client.c] Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
-rw-r--r--fs/ceph/mds_client.c7
-rw-r--r--fs/ceph/mds_client.h3
2 files changed, 7 insertions, 3 deletions
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 9dd6b836ac9e..84edfc60d87a 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -7,7 +7,6 @@
#include <linux/sched.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
-#include <linux/utsname.h>
#include <linux/ratelimit.h>
#include "super.h"
@@ -884,8 +883,8 @@ static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u6
void *p;
const char* metadata[][2] = {
- {"hostname", utsname()->nodename},
- {"kernel_version", utsname()->release},
+ {"hostname", mdsc->nodename},
+ {"kernel_version", init_utsname()->release},
{"entity_id", opt->name ? : ""},
{"root", fsopt->server_path ? : "/"},
{NULL, NULL}
@@ -3539,6 +3538,8 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc)
init_rwsem(&mdsc->pool_perm_rwsem);
mdsc->pool_perm_tree = RB_ROOT;
+ strncpy(mdsc->nodename, utsname()->nodename,
+ sizeof(mdsc->nodename) - 1);
return 0;
}
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index db57ae98ed34..636d6b2ec49c 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -8,6 +8,7 @@
#include <linux/rbtree.h>
#include <linux/spinlock.h>
#include <linux/refcount.h>
+#include <linux/utsname.h>
#include <linux/ceph/types.h>
#include <linux/ceph/messenger.h>
@@ -368,6 +369,8 @@ struct ceph_mds_client {
struct rw_semaphore pool_perm_rwsem;
struct rb_root pool_perm_tree;
+
+ char nodename[__NEW_UTS_LEN + 1];
};
extern const char *ceph_mds_op_name(int op);