dm: move pending queue wake_up end_io_acct

This doesn't fix any bug, just moves wake_up immediately after decrementing
md->pending, for better code readability.

It must be clear to anyone manipulating md->pending to wake up
the queue if md->pending reaches zero, so move the wakeup as close to
the decrementing as possible.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 6963ad1484082bf5d0f8009c60aa1db18eb980c1..dc25d8a07bc77da014e86fc385544dcc69c0c085 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -375,7 +375,7 @@ static void start_io_acct(struct dm_io *io)
        dm_disk(md)->part0.in_flight = atomic_inc_return(&md->pending);
 }
 
-static int end_io_acct(struct dm_io *io)
+static void end_io_acct(struct dm_io *io)
 {
        struct mapped_device *md = io->md;
        struct bio *bio = io->bio;
@@ -391,7 +391,9 @@ static int end_io_acct(struct dm_io *io)
        dm_disk(md)->part0.in_flight = pending =
                atomic_dec_return(&md->pending);
 
-       return !pending;
+       /* nudge anyone waiting on suspend queue */
+       if (!pending)
+               wake_up(&md->wait);
 }
 
 /*
@@ -499,9 +501,7 @@ static void dec_pending(struct dm_io *io, int error)
                        spin_unlock_irqrestore(&io->md->pushback_lock, flags);
                }
 
-               if (end_io_acct(io))
-                       /* nudge anyone waiting on suspend queue */
-                       wake_up(&io->md->wait);
+               end_io_acct(io);
 
                if (io->error != DM_ENDIO_REQUEUE) {
                        blk_add_trace_bio(io->md->queue, io->bio,