From: Jinshan Xiong <jinshan.xiong@intel.com>
Date: Fri, 8 Nov 2013 03:58:19 +0000 (-0800)
Subject: LU-3274 osc: allow to call brw_commit() multiple times
X-Git-Tag: 2.5.57~21
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=refs%2Fchanges%2F15%2F8215%2F2;p=fs%2Flustre-release.git

LU-3274 osc: allow to call brw_commit() multiple times

Sometimes the rq_commit_cb of BRW RPC can be called twice if that RPC
has already committed at reply time. This will cause inaccuracy of
unstable pages accounting and then assertion.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Change-Id: Ic596e1d44e2c27bf13701d2c6c9691562beb7e58
Reviewed-on: http://review.whamcloud.com/8215
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Prakash Surya <surya1@llnl.gov>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/lustre/osc/osc_cache.c b/lustre/osc/osc_cache.c
index 6887309..5885c59 100644
--- a/lustre/osc/osc_cache.c
+++ b/lustre/osc/osc_cache.c
@@ -1811,11 +1811,6 @@ void osc_dec_unstable_pages(struct ptlrpc_request *req)
 	atomic_sub(page_count, &obd_unstable_pages);
 	LASSERT(atomic_read(&obd_unstable_pages) >= 0);
 
-	spin_lock(&req->rq_lock);
-	req->rq_committed = 1;
-	req->rq_unstable  = 0;
-	spin_unlock(&req->rq_lock);
-
 	wake_up_all(&cli->cl_cache->ccc_unstable_waitq);
 }
 
@@ -1845,25 +1840,19 @@ void osc_inc_unstable_pages(struct ptlrpc_request *req)
 	LASSERT(atomic_read(&obd_unstable_pages) >= 0);
 	atomic_add(page_count, &obd_unstable_pages);
 
-	spin_lock(&req->rq_lock);
-
 	/* If the request has already been committed (i.e. brw_commit
 	 * called via rq_commit_cb), we need to undo the unstable page
 	 * increments we just performed because rq_commit_cb wont be
-	 * called again. Otherwise, just set the commit callback so the
-	 * unstable page accounting is properly updated when the request
-	 * is committed */
-	if (req->rq_committed) {
-		/* Drop lock before calling osc_dec_unstable_pages */
+	 * called again. */
+	spin_lock(&req->rq_lock);
+	if (unlikely(req->rq_committed)) {
 		spin_unlock(&req->rq_lock);
+
 		osc_dec_unstable_pages(req);
-		spin_lock(&req->rq_lock);
 	} else {
-		req->rq_unstable  = 1;
-		req->rq_commit_cb = osc_dec_unstable_pages;
+		req->rq_unstable = 1;
+		spin_unlock(&req->rq_lock);
 	}
-
-	spin_unlock(&req->rq_lock);
 }
 
 /* this must be called holding the loi list lock to give coverage to exit_cache,
diff --git a/lustre/osc/osc_request.c b/lustre/osc/osc_request.c
index ed8b962..d1d793a 100644
--- a/lustre/osc/osc_request.c
+++ b/lustre/osc/osc_request.c
@@ -2072,19 +2072,20 @@ static int brw_interpret(const struct lu_env *env,
 
 static void brw_commit(struct ptlrpc_request *req)
 {
-	spin_lock(&req->rq_lock);
 	/* If osc_inc_unstable_pages (via osc_extent_finish) races with
 	 * this called via the rq_commit_cb, I need to ensure
 	 * osc_dec_unstable_pages is still called. Otherwise unstable
 	 * pages may be leaked. */
-	if (req->rq_unstable) {
+	spin_lock(&req->rq_lock);
+	if (likely(req->rq_unstable)) {
+		req->rq_unstable = 0;
 		spin_unlock(&req->rq_lock);
+
 		osc_dec_unstable_pages(req);
-		spin_lock(&req->rq_lock);
 	} else {
 		req->rq_committed = 1;
+		spin_unlock(&req->rq_lock);
 	}
-	spin_unlock(&req->rq_lock);
 }
 
 /**