On 19.01.21 11:57, Roger Pau Monne wrote:

This is inline with the specification described in blkif.h:

  * discard-granularity: should be set to the physical block size if
    node is not present.
  * discard-alignment, discard-secure: should be set to 0 if node not
    present.

This was detected as QEMU would only create the discard-granularity
node but not discard-alignment, and thus the setup done in
blkfront_setup_discard would fail.

Fix blkfront_setup_discard to not fail on missing nodes, and also fix
blkif_set_queue_limits to set the discard granularity to the physical
block size if none is specified in xenbus.

Fixes: ed30bf317c5ce ('xen-blkfront: Handle discard requests.')
Reported-by: Arthur Borsboom <redacted>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen