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Date: Thu, 10 Nov 2016 23:04:38 +0300
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Jens Axboe <axboe@fb.com>, Christoph Hellwig <hch@lst.de>
Cc: Mike Christie <mchristi@redhat.com>,
        Shaun Tancheff <shaun.tancheff@seagate.com>,
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Subject: [patch] block: precedence bug in bio_set_op_attrs() macro
Message-ID: <20161110200438.GA22854@mwanda>
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This code causes a problem for flush_epd_write_bio() because | has
higher precedence than ?: so it basically turns into:

	((bio)->bi_opf |= REQ_SYNC;

Which is wrong.

Fixes: ef295ecf090d ("block: better op and flags encoding")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 562ac46..67fae32 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -208,7 +208,7 @@ enum req_flag_bits {
 
 /* obsolete, don't use in new code */
 #define bio_set_op_attrs(bio, op, op_flags) \
-	((bio)->bi_opf |= (op | op_flags))
+	((bio)->bi_opf |= ((op) | (op_flags)))
 
 static inline bool op_is_write(unsigned int op)
 {