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From:   Huaisheng Ye <yehs2007@zoho.com>
To:     linux-nvdimm@lists.01.org, dan.j.williams@intel.com
Cc:     ross.zwisler@linux.intel.com, willy@infradead.org,
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        linux-fsdevel@vger.kernel.org, colyli@suse.de, chengnt@lenovo.com,
        Huaisheng Ye <yehs1@lenovo.com>
Subject: [PATCH v3 5/6] md/dm-writecache: Don't request pointer dummy_addr when not required
Date:   Mon, 30 Jul 2018 15:15:47 +0800
Message-Id: <20180730071548.9172-6-yehs2007@zoho.com>
In-Reply-To: <20180730071548.9172-1-yehs2007@zoho.com>
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From: Huaisheng Ye <yehs1@lenovo.com>

Function persistent_memory_claim doesn't need to get local pointer
dummy_addr from direct_access. Using NULL instead of having to pass
in a useless local pointer that caller then just throw away.

Suggested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
---
 drivers/md/dm-writecache.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 87107c9..9d79084 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -268,9 +268,8 @@ static int persistent_memory_claim(struct dm_writecache *wc)
 		i = 0;
 		do {
 			long daa;
-			void *dummy_addr;
 			daa = dax_direct_access(wc->ssd_dev->dax_dev, i, p - i,
-						&dummy_addr, &pfn);
+						NULL, &pfn);
 			if (daa <= 0) {
 				r = daa ? daa : -EINVAL;
 				goto err3;
-- 
1.8.3.1