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| author | Jens Axboe <axboe@kernel.dk> | 2018-01-09 17:32:25 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-01-09 17:32:25 +0100 |
| commit | 08b5a6e2a769f720977b245431b45134c0bdd377 (patch) | |
| tree | e2c4716d3299defea72a82eac1c6e19847739f69 /block | |
| parent | blk-mq: rename blk_mq_hw_ctx->queue_rq_srcu to ->srcu (diff) | |
| download | linux-08b5a6e2a769f720977b245431b45134c0bdd377.tar.xz linux-08b5a6e2a769f720977b245431b45134c0bdd377.zip | |
blk-mq: silence false positive warnings in hctx_unlock()
In some stupider versions of gcc, it complains:
block/blk-mq.c: In function ‘blk_mq_complete_request’:
./include/linux/srcu.h:175:2: warning: ‘srcu_idx’ may be used uninitialized in this function [-Wmaybe-uninitialized]
__srcu_read_unlock(sp, idx);
^
block/blk-mq.c:620:6: note: ‘srcu_idx’ was declared here
int srcu_idx;
^
which is completely bogus, since we only use srcu_idx when
hctx->flags & BLK_MQ_F_BLOCKING is set, and that's the case where
hctx_lock() has initialized it.
Just set it to '0' in the normal path in hctx_lock() to silence
this annoying warning.
Fixes: 04ced159cec8 ("blk-mq: move hctx lock/unlock into a helper")
Fixes: 5197c05e16b4 ("blk-mq: protect completion path with RCU")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 0269d44d512e..8de354606690 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -569,9 +569,11 @@ static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx) static void hctx_lock(struct blk_mq_hw_ctx *hctx, int *srcu_idx) { - if (!(hctx->flags & BLK_MQ_F_BLOCKING)) + if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { + /* shut up gcc false positive */ + *srcu_idx = 0; rcu_read_lock(); - else + } else *srcu_idx = srcu_read_lock(hctx->srcu); } |