Later, the low layer (scsi) can decide when to turn back the mem of
req by blk_reclaim_request()
Signed-off-by: Liu Ping Fan <pingf...@linux.vnet.ibm.com>
---
block/blk-core.c | 52 +++++++++++++++++++++++++++++++++-----------------
include/linux/blkdev.h | 6 ++++--
2 files changed, 39 insertions(+), 19 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index beaca2e..7e8a8ae 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2495,7 +2495,7 @@ EXPORT_SYMBOL_GPL(blk_unprep_request);
/*
* queue lock must be held
*/
-static void blk_finish_request(struct request *req, int error, int *drop_ref)
+static void __blk_finish_request(struct request *req, int error, int *drop_ref)
{
bool ref;
@@ -2517,7 +2517,10 @@ static void blk_finish_request(struct request *req, int
error, int *drop_ref)
blk_unprep_request(req);
blk_account_io_done(req);
+}
+void blk_reclaim_request(struct request *req, int error)
+{
if (req->end_io)
req->end_io(req, error);
else {
@@ -2528,6 +2531,12 @@ static void blk_finish_request(struct request *req, int
error, int *drop_ref)
}
}
+static void blk_finish_request(struct request *req, int error, int *drop_ref)
+{
+ __blk_finish_request(req, error, drop_ref);
+ blk_reclaim_request(req, error);
+}
+
/**
* blk_end_bidi_request - Complete a bidi request
* @rq: the request to complete
@@ -2555,7 +2564,11 @@ static bool blk_end_bidi_request(struct request *rq, int
error,
return true;
spin_lock_irqsave(q->queue_lock, flags);
- blk_finish_request(rq, error, drop_ref);
+ /* low level wants to manage ref, so not to reclaim rq */
+ if (drop_ref)
+ __blk_finish_request(rq, error, drop_ref);
+ else
+ blk_finish_request(rq, error, drop_ref);
spin_unlock_irqrestore(q->queue_lock, flags);
return false;
@@ -2608,25 +2621,15 @@ bool blk_end_request(struct request *rq, int error,
unsigned int nr_bytes)
EXPORT_SYMBOL(blk_end_request);
/**
- * blk_end_request_ref - Helper function for drivers to complete the request.
- * @rq: the request being processed
- * @error: %0 for success, < %0 for error
- * @nr_bytes: number of bytes to complete
- *
- * Description:
- * Ends I/O on a number of bytes attached to @rq.
- * If @rq has leftover, sets it up for the next range of segments.
- *
- * Return:
- * %false - we are done with this request
- * %true - still buffers pending for this request
+ * blk_end_request_noreclaim - same as blk_end_request, but not reclaim rq
**/
-bool blk_end_request_ref(struct request *rq, int error, unsigned int nr_bytes,
- int *drop_ref)
+bool blk_end_request_noreclaim(struct request *rq, int error,
+ unsigned int nr_bytes, int *drop_ref)
{
+ BUG_ON(!drop_ref);
return blk_end_bidi_request(rq, error, nr_bytes, 0, drop_ref);
}
-EXPORT_SYMBOL(blk_end_request_ref);
+EXPORT_SYMBOL(blk_end_request_noreclaim);
/**
* blk_end_request_all - Helper function for drives to finish the request.
@@ -2650,6 +2653,21 @@ void blk_end_request_all(struct request *rq, int error)
}
EXPORT_SYMBOL(blk_end_request_all);
+void blk_end_request_all_noreclaim(struct request *rq, int error)
+{
+ bool pending;
+ unsigned int bidi_bytes = 0;
+ int ref;
+
+ if (unlikely(blk_bidi_rq(rq)))
+ bidi_bytes = blk_rq_bytes(rq->next_rq);
+
+ pending = blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes,
+ &ref);
+ BUG_ON(pending);
+}
+EXPORT_SYMBOL(blk_end_request_all_noreclaim);
+
/**
* blk_end_request_cur - Helper function to finish the current request chunk.
* @rq: the request to finish the current chunk for
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 7a2e79f..70c65d2 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -772,6 +772,7 @@ extern void generic_make_request(struct bio *bio);
extern void blk_rq_init(struct request_queue *q, struct request *rq);
extern void blk_put_request(struct request *);
extern void __blk_put_request(struct request_queue *, struct request *);
+extern void blk_reclaim_request(struct request *req, int error);
extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
extern struct request *blk_make_request(struct request_queue *, struct bio *,
gfp_t);
@@ -934,11 +935,12 @@ extern struct request *blk_fetch_request(struct
request_queue *q);
*/
extern bool blk_update_request(struct request *rq, int error,
unsigned int nr_bytes);
-extern bool blk_end_request_ref(struct request *rq, int error,
- unsigned int nr_bytes, int *drop_ref);
extern bool blk_end_request(struct request *rq, int error,
unsigned int nr_bytes);
+extern bool blk_end_request_noreclaim(struct request *rq, int error,
+ unsigned int nr_bytes, int *drop_ref);
extern void blk_end_request_all(struct request *rq, int error);
+extern void blk_end_request_all_noreclaim(struct request *rq, int error);
extern bool blk_end_request_cur(struct request *rq, int error);
extern bool blk_end_request_err(struct request *rq, int error);
extern bool __blk_end_request(struct request *rq, int error,
--
1.8.1.4
--
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