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>
This commit is contained in:
Yan, Zheng 2017-09-11 12:10:08 +08:00 committed by Ilya Dryomov
parent 29a0cfbf91
commit 717e6f2893
2 changed files with 7 additions and 3 deletions

View File

@ -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;
}

View File

@ -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);