On 09/22/12 00:47, Mike Snitzer wrote:
> @@ -1651,19 +1654,31 @@ static void dm_request_fn(struct request
> if (!rq)
> goto delay_and_out;
>
> + clone = rq->special;
> +
> /* always use block 0 to find the target for flushes for now */
> pos = 0;
> if (!(rq->cmd_flags & REQ_FLUSH))
> pos = blk_rq_pos(rq);
>
> ti = dm_table_find_target(map, pos);
> - BUG_ON(!dm_target_is_valid(ti));
> + if (!dm_target_is_valid(ti)) {
> + /*
> + * Must perform setup, that dm_done() requires,
> + * before calling dm_kill_unmapped_request
> + */
> + DMERR_LIMIT("request attempted access beyond the end of device");
> + blk_start_request(rq);
> + atomic_inc(&md->pending[rq_data_dir(clone)]);
> + dm_get(md);
> + dm_kill_unmapped_request(clone, -EIO);
> + goto out;
This "goto out" should be "continue" so that request_fn
process next requests in the queue.
Also I think introducing a function dm_start_request()
will make this part of code a little bit easier for reading.
An edited patch is attached.
--
Jun'ichi Nomura, NEC Corporation
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index e24143c..3977f8d 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -865,7 +865,10 @@ static void dm_done(struct request *clone, int error, bool mapped)
{
int r = error;
struct dm_rq_target_io *tio = clone->end_io_data;
- dm_request_endio_fn rq_end_io = tio->ti->type->rq_end_io;
+ dm_request_endio_fn rq_end_io = NULL;
+
+ if (tio->ti)
+ rq_end_io = tio->ti->type->rq_end_io;
if (mapped && rq_end_io)
r = rq_end_io(tio->ti, clone, error, &tio->info);
@@ -1566,15 +1569,6 @@ static int map_request(struct dm_target *ti, struct request *clone,
int r, requeued = 0;
struct dm_rq_target_io *tio = clone->end_io_data;
- /*
- * Hold the md reference here for the in-flight I/O.
- * We can't rely on the reference count by device opener,
- * because the device may be closed during the request completion
- * when all bios are completed.
- * See the comment in rq_completed() too.
- */
- dm_get(md);
-
tio->ti = ti;
r = ti->type->map_rq(ti, clone, &tio->info);
switch (r) {
@@ -1606,6 +1600,26 @@ static int map_request(struct dm_target *ti, struct request *clone,
return requeued;
}
+static struct request *dm_start_request(struct mapped_device *md, struct request *orig)
+{
+ struct request *clone;
+
+ blk_start_request(orig);
+ clone = orig->special;
+ atomic_inc(&md->pending[rq_data_dir(clone)]);
+
+ /*
+ * Hold the md reference here for the in-flight I/O.
+ * We can't rely on the reference count by device opener,
+ * because the device may be closed during the request completion
+ * when all bios are completed.
+ * See the comment in rq_completed() too.
+ */
+ dm_get(md);
+
+ return clone;
+}
+
/*
* q->request_fn for request-based dm.
* Called with the queue lock held.
@@ -1635,14 +1649,21 @@ static void dm_request_fn(struct request_queue *q)
pos = blk_rq_pos(rq);
ti = dm_table_find_target(map, pos);
- BUG_ON(!dm_target_is_valid(ti));
+ if (!dm_target_is_valid(ti)) {
+ /*
+ * Must perform setup, that dm_done() requires,
+ * before calling dm_kill_unmapped_request
+ */
+ DMERR_LIMIT("request attempted access beyond the end of device");
+ clone = dm_start_request(md, rq);
+ dm_kill_unmapped_request(clone, -EIO);
+ continue;
+ }
if (ti->type->busy && ti->type->busy(ti))
goto delay_and_out;
- blk_start_request(rq);
- clone = rq->special;
- atomic_inc(&md->pending[rq_data_dir(clone)]);
+ clone = dm_start_request(md, rq);
spin_unlock(q->queue_lock);
if (map_request(ti, clone, md))
@@ -1662,8 +1683,6 @@ delay_and_out:
blk_delay_queue(q, HZ / 10);
out:
dm_table_put(map);
-
- return;
}
int dm_underlying_device_busy(struct request_queue *q)
--
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