loop: cleanup loop_config_discard

Initialize the local variables for the discard max sectors and
granularity to zero as a sensible default, and then merge the
calls assigning them to the queue limits.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240213073425.1621680-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 3f855cc..7abeb58 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -755,7 +755,8 @@ static void loop_config_discard(struct loop_device *lo)
        struct file *file = lo->lo_backing_file;
        struct inode *inode = file->f_mapping->host;
        struct request_queue *q = lo->lo_queue;
-       u32 granularity, max_discard_sectors;
+       u32 granularity = 0, max_discard_sectors = 0;
+       struct kstatfs sbuf;
 
        /*
         * If the backing device is a block device, mirror its zeroing
@@ -775,29 +776,17 @@ static void loop_config_discard(struct loop_device *lo)
         * We use punch hole to reclaim the free space used by the
         * image a.k.a. discard.
         */
-       } else if (!file->f_op->fallocate) {
-               max_discard_sectors = 0;
-               granularity = 0;
-
-       } else {
-               struct kstatfs sbuf;
-
+       } else if (file->f_op->fallocate && !vfs_statfs(&file->f_path, &sbuf)) {
                max_discard_sectors = UINT_MAX >> 9;
-               if (!vfs_statfs(&file->f_path, &sbuf))
-                       granularity = sbuf.f_bsize;
-               else
-                       max_discard_sectors = 0;
+               granularity = sbuf.f_bsize;
        }
 
-       if (max_discard_sectors) {
+       blk_queue_max_discard_sectors(q, max_discard_sectors);
+       blk_queue_max_write_zeroes_sectors(q, max_discard_sectors);
+       if (max_discard_sectors)
                q->limits.discard_granularity = granularity;
-               blk_queue_max_discard_sectors(q, max_discard_sectors);
-               blk_queue_max_write_zeroes_sectors(q, max_discard_sectors);
-       } else {
+       else
                q->limits.discard_granularity = 0;
-               blk_queue_max_discard_sectors(q, 0);
-               blk_queue_max_write_zeroes_sectors(q, 0);
-       }
 }
 
 struct loop_worker {