K 10
svn:author
V 4
grog
K 8
svn:date
V 27
1999-08-07T08:13:23.000000Z
K 7
svn:log
V 905
Import RAID-5 code.
Add Cybernet copyright.

OK'd-by:     Chuck Jacobus <chuck@cybernet.com>

logrq: save device major and minor numbers to compensate for lost
  dev_t.

launch_requests: Don't issue requests which are marked
  XFR_BAD_SUBDISK.  This may make things easier in bre().

bre:
  Rearrange.
  - Change some comments
  - Recognize holes in plex structure.  Formerly this could lead to
    incorrect write to the plex.  Return REQUEST_DEGRADED on a read
    request, but carry on to the bitter end on a write request, and
    mark the requests for the inaccessible subdisks with
    XFR_BAD_SUBDISK.
  - return REQUEST_EOF if the requested transfer goes beyond the end
    of the plex.  This is not an error, since other plexes may go
    further into the volume address space.

build_read_request:
  Handle REQUEST_DEGRADED returned from bre().

sdio:
  Lock buffer before issuing the requests.

END