At the moment ve->mnt_nr is not atomic and not guarded by any lock => convert it to atomic_t in order to avoid races on updates
https://jira.sw.ru/browse/PSBM-69880 Signed-off-by: Konstantin Khorenko <khore...@virtuozzo.com> --- include/linux/ve.h | 9 +++++---- kernel/ve/ve.c | 4 ++-- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/include/linux/ve.h b/include/linux/ve.h index 94dd068..f430ccd 100644 --- a/include/linux/ve.h +++ b/include/linux/ve.h @@ -122,7 +122,7 @@ struct ve_struct { /* Number of mounts. May become unbalanced if VE0 mounts something * and the VE unmounts it. This is acceptable. */ - int mnt_nr; + atomic_t mnt_nr; #ifdef CONFIG_COREDUMP char core_pattern[CORENAME_MAX_SIZE]; #endif @@ -232,17 +232,18 @@ static inline int ve_mount_allowed(void) { struct ve_struct *ve = get_exec_env(); - return ve_is_super(ve) || ve->mnt_nr < (int)sysctl_ve_mount_nr; + return ve_is_super(ve) || + atomic_read(&ve->mnt_nr) < (int)sysctl_ve_mount_nr; } static inline void ve_mount_nr_inc(void) { - get_exec_env()->mnt_nr++; + atomic_inc(&get_exec_env()->mnt_nr); } static inline void ve_mount_nr_dec(void) { - get_exec_env()->mnt_nr--; + atomic_dec(&get_exec_env()->mnt_nr); } #else /* CONFIG_VE */ diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c index 140f160..0a835f3 100644 --- a/kernel/ve/ve.c +++ b/kernel/ve/ve.c @@ -78,7 +78,7 @@ struct ve_struct ve0 = { #endif .sched_lat_ve.cur = &ve0_lat_stats, .init_cred = &init_cred, - .mnt_nr = 0, + .mnt_nr = ATOMIC_INIT(0), .netns_avail_nr = ATOMIC_INIT(INT_MAX), .netns_max_nr = INT_MAX, .netif_avail_nr = ATOMIC_INIT(INT_MAX), @@ -692,7 +692,7 @@ static struct cgroup_subsys_state *ve_create(struct cgroup *cg) ve->aio_nr = 0; ve->aio_max_nr = AIO_MAX_NR_DEFAULT; #endif - ve->mnt_nr = 0; + atomic_set(&ve->mnt_nr, 0); #ifdef CONFIG_COREDUMP strcpy(ve->core_pattern, "core"); -- 1.8.3.1 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
