When user hot-unplug a disk which is busy serving I/O, __blk_run_queue
might be unable to drain all the requests. As a result, the
blk_drain_queue() would loop forever and blk_cleanup_queue would not
return. So hot-unplug will fail.
This patch adds a callback in blk_drain_queue() for low lever driver to
abort requests.
Currently, this is useful for virtio-blk to do cleanup in hot-unplug.
Cc: Jens Axboe <ax...@kernel.dk>
Cc: Tejun Heo <t...@kernel.org>
Cc: linux-fsde...@vger.kernel.org
Cc: Rusty Russell <ru...@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <m...@redhat.com>
Cc: virtualizat...@lists.linux-foundation.org
Cc: kvm@vger.kernel.org
Signed-off-by: Asias He <as...@redhat.com>
---
block/blk-core.c | 3 +++
block/blk-settings.c | 12 ++++++++++++
include/linux/blkdev.h | 3 +++
3 files changed, 18 insertions(+)
diff --git a/block/blk-core.c b/block/blk-core.c
index 1f61b74..ca42fd7 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -369,6 +369,9 @@ void blk_drain_queue(struct request_queue *q, bool
drain_all)
if (drain_all)
blk_throtl_drain(q);
+ if (q->abort_queue_fn)
+ q->abort_queue_fn(q);
+
/*
* This function might be called on a queue which failed
* driver init after queue creation. Some drivers
diff --git a/block/blk-settings.c b/block/blk-settings.c
index d3234fc..83ccb48 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -100,6 +100,18 @@ void blk_queue_lld_busy(struct request_queue *q,
lld_busy_fn *fn)
EXPORT_SYMBOL_GPL(blk_queue_lld_busy);
/**
+ * blk_queue_abort_queue - set driver specific abort function
+ * @q: queue
+ * @mbfn: abort_queue_fn
+ */
+void blk_queue_abort_queue(struct request_queue *q, abort_queue_fn *afn)
+{
+ q->abort_queue_fn = afn;
+}
+EXPORT_SYMBOL(blk_queue_abort_queue);
+
+
+/**
* blk_set_default_limits - reset limits to default values
* @lim: the queue_limits structure to reset
*
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 2aa2466..e2d58bd 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -200,6 +200,7 @@ struct request_pm_state
typedef void (request_fn_proc) (struct request_queue *q);
typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
+typedef void (abort_queue_fn) (struct request_queue *q);
typedef int (prep_rq_fn) (struct request_queue *, struct request *);
typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
@@ -282,6 +283,7 @@ struct request_queue {
request_fn_proc *request_fn;
make_request_fn *make_request_fn;
+ abort_queue_fn *abort_queue_fn;
prep_rq_fn *prep_rq_fn;
unprep_rq_fn *unprep_rq_fn;
merge_bvec_fn *merge_bvec_fn;
@@ -821,6 +823,7 @@ extern struct request_queue
*blk_init_allocated_queue(struct request_queue *,
request_fn_proc *,
spinlock_t *);
extern void blk_cleanup_queue(struct request_queue *);
extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
+extern void blk_queue_abort_queue(struct request_queue *, abort_queue_fn *);
extern void blk_queue_bounce_limit(struct request_queue *, u64);
extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
--
1.7.10.1
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