From: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Mon, 15 Oct 2012 20:40:07 +0000 (-0700)
Subject: Condition variable usage, zilog->zl_cv_batch
X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=commitdiff_plain;h=8c0712fd88d3cf60dc9db5392b005583d540dc69;p=zfs.git

Condition variable usage, zilog->zl_cv_batch

The following incorrect usage of cv_signal and cv_broadcast()
was caught by code inspection.  The cv_signal and cv_broadcast()
functions must be called under the associated mutex to preventing
racing with cv_wait().

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
---

diff --git a/module/zfs/zil.c b/module/zfs/zil.c
index 292aea2..e76e5ec 100644
--- a/module/zfs/zil.c
+++ b/module/zfs/zil.c
@@ -1560,13 +1560,14 @@ zil_commit(zilog_t *zilog, uint64_t foid)
 	zil_commit_writer(zilog);
 	zilog->zl_com_batch = mybatch;
 	zilog->zl_writer = B_FALSE;
-	mutex_exit(&zilog->zl_lock);
 
 	/* wake up one thread to become the next writer */
 	cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]);
 
 	/* wake up all threads waiting for this batch to be committed */
 	cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]);
+
+	mutex_exit(&zilog->zl_lock);
 }
 
 /*