btrfs: raid56: simplify error handling and code flow in raid56_parity_write

Handle the error return on alloc_rbio failure directly instead of using
a goto and remove the queue_rbio goto label by moving the plugged
check into the if branch.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index d095c07a152df3527681de1123d2d69d78387d75..8073fa004870b6e0f98e355c205f82f18c9c3b48 100644 (file)
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -1667,12 +1667,12 @@ void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc)
        struct btrfs_raid_bio *rbio;
        struct btrfs_plug_cb *plug = NULL;
        struct blk_plug_cb *cb;
-       int ret = 0;
 
        rbio = alloc_rbio(fs_info, bioc);
        if (IS_ERR(rbio)) {
-               ret = PTR_ERR(rbio);
-               goto fail;
+               bio->bi_status = errno_to_blk_status(PTR_ERR(rbio));
+               bio_endio(bio);
+               return;
        }
        rbio->operation = BTRFS_RBIO_WRITE;
        rbio_add_bio(rbio, bio);
@@ -1681,31 +1681,24 @@ void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc)
         * Don't plug on full rbios, just get them out the door
         * as quickly as we can
         */
-       if (rbio_is_full(rbio))
-               goto queue_rbio;
-
-       cb = blk_check_plugged(raid_unplug, fs_info, sizeof(*plug));
-       if (cb) {
-               plug = container_of(cb, struct btrfs_plug_cb, cb);
-               if (!plug->info) {
-                       plug->info = fs_info;
-                       INIT_LIST_HEAD(&plug->rbio_list);
+       if (!rbio_is_full(rbio)) {
+               cb = blk_check_plugged(raid_unplug, fs_info, sizeof(*plug));
+               if (cb) {
+                       plug = container_of(cb, struct btrfs_plug_cb, cb);
+                       if (!plug->info) {
+                               plug->info = fs_info;
+                               INIT_LIST_HEAD(&plug->rbio_list);
+                       }
+                       list_add_tail(&rbio->plug_list, &plug->rbio_list);
+                       return;
                }
-               list_add_tail(&rbio->plug_list, &plug->rbio_list);
-               return;
        }
-queue_rbio:
+
        /*
         * Either we don't have any existing plug, or we're doing a full stripe,
-        * can queue the rmw work now.
+        * queue the rmw work now.
         */
        start_async_work(rbio, rmw_rbio_work);
-
-       return;
-
-fail:
-       bio->bi_status = errno_to_blk_status(ret);
-       bio_endio(bio);
 }
 
 static int verify_one_sector(struct btrfs_raid_bio *rbio,