From: Sebastien Buisson <sbuis...@ddn.com> Fix 'data race condition' defects found by Coverity version 6.5.0:
Data race condition (MISSING_LOCK) Accessing variable without holding lock. Elsewhere, this variable is accessed with lock held. This patch is dedicated to code fragments involving oap_lock. Signed-off-by: Sebastien Buisson <sbuis...@ddn.com> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-2744 Reviewed-on: http://review.whamcloud.com/6572 Reviewed-by: Oleg Drokin <oleg.dro...@intel.com> Reviewed-by: Andreas Dilger <andreas.dil...@intel.com> Signed-off-by: James Simmons <jsimm...@infradead.org> --- drivers/staging/lustre/lustre/osc/osc_cache.c | 8 ++++++++ drivers/staging/lustre/lustre/osc/osc_io.c | 2 ++ 2 files changed, 10 insertions(+), 0 deletions(-) diff --git a/drivers/staging/lustre/lustre/osc/osc_cache.c b/drivers/staging/lustre/lustre/osc/osc_cache.c index 956d57b..846be76 100644 --- a/drivers/staging/lustre/lustre/osc/osc_cache.c +++ b/drivers/staging/lustre/lustre/osc/osc_cache.c @@ -1147,7 +1147,9 @@ static int osc_extent_make_ready(const struct lu_env *env, last->oap_count = osc_refresh_count(env, last, OBD_BRW_WRITE); LASSERT(last->oap_count > 0); LASSERT(last->oap_page_off + last->oap_count <= PAGE_CACHE_SIZE); + spin_lock(&last->oap_lock); last->oap_async_flags |= ASYNC_COUNT_STABLE; + spin_unlock(&last->oap_lock); } /* for the rest of pages, we don't need to call osf_refresh_count() @@ -1156,7 +1158,9 @@ static int osc_extent_make_ready(const struct lu_env *env, list_for_each_entry(oap, &ext->oe_pages, oap_pending_item) { if (!(oap->oap_async_flags & ASYNC_COUNT_STABLE)) { oap->oap_count = PAGE_CACHE_SIZE - oap->oap_page_off; + spin_lock(&last->oap_lock); oap->oap_async_flags |= ASYNC_COUNT_STABLE; + spin_unlock(&last->oap_lock); } } @@ -2350,6 +2354,10 @@ int osc_queue_async_io(const struct lu_env *env, struct cl_io *io, oap->oap_cmd = cmd; oap->oap_page_off = ops->ops_from; oap->oap_count = ops->ops_to - ops->ops_from; + /* + * No need to hold a lock here, + * since this page is not in any list yet. + */ oap->oap_async_flags = 0; oap->oap_brw_flags = brw_flags; diff --git a/drivers/staging/lustre/lustre/osc/osc_io.c b/drivers/staging/lustre/lustre/osc/osc_io.c index cf7743d..0f50465 100644 --- a/drivers/staging/lustre/lustre/osc/osc_io.c +++ b/drivers/staging/lustre/lustre/osc/osc_io.c @@ -168,8 +168,10 @@ static int osc_io_submit(const struct lu_env *env, } cl_page_list_move(qout, qin, page); + spin_lock(&oap->oap_lock); oap->oap_async_flags = ASYNC_URGENT|ASYNC_READY; oap->oap_async_flags |= ASYNC_COUNT_STABLE; + spin_unlock(&oap->oap_lock); osc_page_submit(env, opg, crt, brw_flags); list_add_tail(&oap->oap_pending_item, &list); -- 1.7.1
