Theoretically, request only flags in enum rq_flag_bits can bigger
than 31 after we add some new flags in the future, so we can't
store REQ_IO_STAT in op_flags which is a int type in __get_request().
Actually, when REQ_IO_STAT become 31, the most-significant bit of
op_flags will be 1, and OR it to ->cmd_flags will cause the top 32
bits of ->cmd_flags become 1.
Fix it by using a u64-type object to store flags.
Signed-off-by: Wei Fang <fangwei1@xxxxxxxxxx>
---
block/blk-core.c | 11 ++++++-----
1 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index c94c7ad..3860b7d 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1077,6 +1077,7 @@ static struct request *__get_request(struct request_list *rl, int op,
struct io_cq *icq = NULL;
const bool is_sync = rw_is_sync(op, op_flags) != 0;
int may_queue;
+ u64 cmd_flags = (u64)(unsigned int)op_flags;
if (unlikely(blk_queue_dying(q)))
return ERR_PTR(-ENODEV);
@@ -1125,7 +1126,7 @@ static struct request *__get_request(struct request_list *rl, int op,
/*
* Decide whether the new request will be managed by elevator. If
- * so, mark @op_flags and increment elvpriv. Non-zero elvpriv will
+ * so, mark @cmd_flags and increment elvpriv. Non-zero elvpriv will
* prevent the current elevator from being destroyed until the new
* request is freed. This guarantees icq's won't be destroyed and
* makes creating new ones safe.
@@ -1134,14 +1135,14 @@ static struct request *__get_request(struct request_list *rl, int op,
* it will be created after releasing queue_lock.
*/
if (blk_rq_should_init_elevator(bio) && !blk_queue_bypass(q)) {
- op_flags |= REQ_ELVPRIV;
+ cmd_flags |= REQ_ELVPRIV;
q->nr_rqs_elvpriv++;
if (et->icq_cache && ioc)
icq = ioc_lookup_icq(ioc, q);
}
if (blk_queue_io_stat(q))
- op_flags |= REQ_IO_STAT;
+ cmd_flags |= REQ_IO_STAT;
spin_unlock_irq(q->queue_lock);
/* allocate and init request */
@@ -1151,10 +1152,10 @@ static struct request *__get_request(struct request_list *rl, int op,
blk_rq_init(q, rq);
blk_rq_set_rl(rq, rl);
- req_set_op_attrs(rq, op, op_flags | REQ_ALLOCED);
+ req_set_op_attrs(rq, op, cmd_flags | REQ_ALLOCED);
/* init elvpriv */
- if (op_flags & REQ_ELVPRIV) {
+ if (cmd_flags & REQ_ELVPRIV) {
if (unlikely(et->icq_cache && !icq)) {
if (ioc)
icq = ioc_create_icq(ioc, q, gfp_mask);
--
1.7.1
--
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