From 82281bc0c31ccd3a0733c678ad0f0a19ca59246d Mon Sep 17 00:00:00 2001 From: Sebastien Buisson Date: Tue, 12 Apr 2016 16:14:01 -0400 Subject: [PATCH] staging: lustre: osc: fix race issues thanks to oap_lock 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 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-2744 Reviewed-on: http://review.whamcloud.com/6572 Reviewed-by: Oleg Drokin Reviewed-by: Andreas Dilger Signed-off-by: James Simmons Signed-off-by: Greg Kroah-Hartman --- drivers/staging/lustre/lustre/osc/osc_cache.c | 8 ++++++++ drivers/staging/lustre/lustre/osc/osc_io.c | 2 ++ 2 files changed, 10 insertions(+) diff --git a/drivers/staging/lustre/lustre/osc/osc_cache.c b/drivers/staging/lustre/lustre/osc/osc_cache.c index de8c825..8263a85 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_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_SIZE - oap->oap_page_off; + spin_lock(&last->oap_lock); oap->oap_async_flags |= ASYNC_COUNT_STABLE; + spin_unlock(&last->oap_lock); } } @@ -2327,6 +2331,10 @@ 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 9d67fca2..d534b0e 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); -- 2.7.4