TAKE 913531 - recovery of v2 logs of log record size of 256K will fail on Linux

[FSG QA <fsgqa@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx>]

Remove the 128K limitation on pagebuf_get_no_daddr() and allow
the kmem_alloc() to fail.

This will get recovery of 256K happening (assuming it has no
problems getting 256K for its buffer).
pv913534 (todo) addresses the possibility of using smaller buffers
in v2 log recovery.

--Tim

Date:  Tue May  4 21:52:50 PDT 2004
Workarea:  snap.melbourne.sgi.com:/home/fsgqa/qa/xfs-linux
Inspected by:  hch@xxxxxx,nathans@xxxxxxx

The following file(s) were checked into:
  bonnie.engr.sgi.com:/isms/xfs-kern/xfs-linux


Modid:  xfs-linux:xfs-kern:171201a
xfs_log.c - 1.293
        - Print out error code if recovery fails.

linux-2.6/xfs_buf.c - 1.166
        - Remove the 128K limitiation on pagebuf_get_no_daddr() and allow
          the kmem_alloc to fail.

linux-2.6/kmem.h - 1.24
        - Add KM_MAYFAIL and if not KM_MAYFAIL set then set __GFP_NOFAIL.

linux-2.4/xfs_buf.c - 1.186
        - Remove the 128K limitiation on pagebuf_get_no_daddr() and allow
          the kmem_alloc to fail.

linux-2.4/kmem.h - 1.25
        - Add KM_MAYFAIL macro. 
          Rearrange an if for setting of lflags - only clear GFP_FS for
          GFP_KERNEL.

linux-2.4/kmem.c - 1.33
        - Don't panic on kmem_alloc with KM_SLEEP if KM_MAYFAIL is also set.