Illumos 5960, 5925

5960 zfs recv should prefetch indirect blocks
5925 zfs receive -o origin=
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>

References:

https://www.illumos.org/issues/5960
https://www.illumos.org/issues/5925
https://github.com/illumos/illumos-gate/commit/a2cdcdd

Porting notes:

• [lib/libzfs/libzfs_sendrecv.c]
  • b8864a2 Fix gcc cast warnings
  • 325f023 Add linux kernel device support
  • 5c3f61e Increase Linux pipe buffer size on 'zfs receive'
• [module/zfs/zfs_vnops.c]
  • 3558fd7 Prototype/structure update for Linux
  • c12e3a5 Restructure zfs_readdir() to fix regressions
• [module/zfs/zvol.c]
  • Function @zvol_map_block() isn't needed in ZoL
  • 9965059 Prefetch start and end of volumes
• [module/zfs/dmu.c]
  • Fixed ISO C90 - mixed declarations and code
  • Function dmu_prefetch() 'int i' is initialized before the following code block (c90 vs. c99)
• [module/zfs/dbuf.c]
  • fc5bb51 Fix stack dbuf_hold_impl()
  • 9b67f60 Illumos 4757, 4913
  • 34229a2 Reduce stack usage for recursive traverse_visitbp()
• [module/zfs/dmu_send.c]
  • Fixed ISO C90 - mixed declarations and code
  • b58986e Use large stacks when available
  • 241b541 Illumos 5959 - clean up per-dataset feature count code
  • 77aef6f Use vmem_alloc() for nvlists
  • 00b4602 Add linux kernel memory support

Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>