md: Explicitly create command-line configured devices

Boot-time assembly of arrays with md= command-line arguments breaks when
CONFIG_BLOCK_LEGACY_AUTOLOAD is unset. md_setup_drive() in md-autodetect.c
calls blkdev_get_by_dev(), assuming this implicitly creates the block
device.

Fix this by attempting to md_alloc() the array first. As in the probe path,
ignore any error as failure is caught by blkdev_get_by_dev() anyway.

Signed-off-by: Chris Webb <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Song Liu <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions