target/linux/generic/hack-4.19/550-loop-Report-EOPNOTSUPP-properly.patch

   1 From 2e864386e62e702a343be2507062ee08d5dfc810 Mon Sep 17 00:00:00 2001
   2 From: Evan Green <evgreen@chromium.org>
   3 Date: Thu, 14 Nov 2019 15:50:07 -0800
   4 Subject: loop: Report EOPNOTSUPP properly
   5
   6 Properly plumb out EOPNOTSUPP from loop driver operations, which may
   7 get returned when for instance a discard operation is attempted but not
   8 supported by the underlying block device. Before this change, everything
   9 was reported in the log as an I/O error, which is scary and not
  10 helpful in debugging.
  11
  12 Signed-off-by: Evan Green <evgreen@chromium.org>
  13 Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
  14 Reviewed-by: Bart Van Assche <bvanassche@acm.org>
  15 ---
  16  drivers/block/loop.c | 7 +++++--
  17  1 file changed, 5 insertions(+), 2 deletions(-)
  18
  19 --- a/drivers/block/loop.c
  20 +++ b/drivers/block/loop.c
  21 @@ -460,7 +460,7 @@ static void lo_complete_rq(struct reques
  22         if (!cmd->use_aio || cmd->ret < 0 || cmd->ret == blk_rq_bytes(rq) ||
  23             req_op(rq) != REQ_OP_READ) {
  24                 if (cmd->ret < 0)
  25 -                       ret = BLK_STS_IOERR;
  26 +                       ret = errno_to_blk_status(cmd->ret);
  27                 goto end_io;
  28         }
  29
  30 @@ -1904,7 +1904,10 @@ static void loop_handle_cmd(struct loop_
  31   failed:
  32         /* complete non-aio request */
  33         if (!cmd->use_aio || ret) {
  34 -               cmd->ret = ret ? -EIO : 0;
  35 +               if (ret == -EOPNOTSUPP)
  36 +                       cmd->ret = ret;
  37 +               else
  38 +                       cmd->ret = ret ? -EIO : 0;
  39                 blk_mq_complete_request(rq);
  40         }
  41  }