[PATCH v3 0/2] hw/block/block.c: improve confusing error

[Manos Pitsidianakis <manos.pitsidianakis@linaro.org>]

In cases where a device tries to read more bytes than the block device
contains with the blk_check_size_and_read_all() function, the error is
vague: "device requires X bytes, block backend provides Y bytes".

This patch changes the errors of this function to include the block
backend name, the device id and device type name where appropriate.

Version 3:
- Changed phrasing "%s device with id='%s'" to "%s device '%s'" since
  second parameter might be either device id or device path.
    (thanks Stefan Hajnoczi <stefanha@redhat.com>)

Version 2:
- Assert dev is not NULL on qdev_get_human_name
    (thanks Phil Mathieu-Daudé <philmd@linaro.org>)

Manos Pitsidianakis (2):
  hw/core/qdev.c: add qdev_get_human_name()
  hw/block/block.c: improve confusing blk_check_size_and_read_all()
    error

 include/hw/block/block.h |  4 ++--
 include/hw/qdev-core.h   | 14 ++++++++++++++
 hw/block/block.c         | 25 +++++++++++++++----------
 hw/block/m25p80.c        |  3 ++-
 hw/block/pflash_cfi01.c  |  4 ++--
 hw/block/pflash_cfi02.c  |  2 +-
 hw/core/qdev.c           |  8 ++++++++
 7 files changed, 44 insertions(+), 16 deletions(-)

Range-diff against v2:
1:  5fb5879708 ! 1:  8b566bfced hw/core/qdev.c: add qdev_get_human_name()
    @@ Commit message
         Add a simple method to return some kind of human readable identifier for
         use in error messages.
     
    +    Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
         Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
     
      ## include/hw/qdev-core.h ##
2:  8e7eb17fbd ! 2:  7260eadff2 hw/block/block.c: improve confusing blk_check_size_and_read_all() error
    @@ hw/block/block.c: static int blk_pread_nonzeroes(BlockBackend *blk, hwaddr size,
     -                   "block backend provides %" PRIu64 " bytes",
     -                   size, blk_len);
     +        dev_id = qdev_get_human_name(dev);
    -+        error_setg(errp, "%s device with id='%s' requires %" HWADDR_PRIu
    ++        error_setg(errp, "%s device '%s' requires %" HWADDR_PRIu
     +                   " bytes, %s block backend provides %" PRIu64 " bytes",
     +                   object_get_typename(OBJECT(dev)), dev_id, size,
     +                   blk_name(blk), blk_len);
    @@ hw/block/block.c: bool blk_check_size_and_read_all(BlockBackend *blk, void *buf,
     -        error_setg_errno(errp, -ret, "can't read block backend");
     +        dev_id = qdev_get_human_name(dev);
     +        error_setg_errno(errp, -ret, "can't read %s block backend"
    -+                         "for %s device with id='%s'",
    ++                         " for %s device '%s'",
     +                         blk_name(blk), object_get_typename(OBJECT(dev)),
     +                         dev_id);
              return false;

base-commit: 11be70677c70fdccd452a3233653949b79e97908
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