Commit Graph

2 Commits

Author SHA1 Message Date
Boaz Harrosh ce5d36aac2 ore: Support for raid 6
This simple patch adds support for raid6 to the ORE.
Most operations and calculations where already for the general
case. Only things left:
* call async_gen_syndrome() in the case of raid6
  (NOTE that the raid6 math is the one supported by the Linux Kernel
   see: crypto/async_tx/async_pq.c)
* call _ore_add_parity_unit() twice with only last call generating
  the redundancy pages.

* Fix couple BUGS in old code
  a. In reads when parity==2 it can happen that per_dev->length=0
     but per_dev->offset was set and adjusted by _ore_add_sg_seg().
     Don't let it be overwritten.
  b. The all 'cur_comp > starting_dev' thing to determine if:
       "per_dev->offset is in the current stripe number or the
       next one."
     Was a complete raid5/4 accident. When parity==2 this is not
     at all true usually. All we need to do is increment si->ob_offset
     once we pass by the first parity device.
     (This also greatly simplifies the code, amen)
  c. Calculation of si->dev rotation can overflow when parity==2.

* Then last enable raid6 in ore_verify_layout()

I want to deeply thank Daniel Gryniewicz who found first all the
bugs in the old raid code, and inspired these patches:
	Inspired-by Daniel Gryniewicz <dang@linuxbox.com>

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2014-05-22 14:48:15 +03:00
Boaz Harrosh 831c2dc5f4 ore: FIX breakage when MISC_FILESYSTEMS is not set
As Reported by Randy Dunlap

When MISC_FILESYSTEMS is not enabled and NFS4.1 is:

fs/built-in.o: In function `objio_alloc_io_state':
objio_osd.c:(.text+0xcb525): undefined reference to `ore_get_rw_state'
fs/built-in.o: In function `_write_done':
objio_osd.c:(.text+0xcb58d): undefined reference to `ore_check_io'
fs/built-in.o: In function `_read_done':
...

When MISC_FILESYSTEMS, which is more of a GUI thing then anything else,
is not selected. exofs/Kconfig is never examined during Kconfig,
and it can not do it's magic stuff to automatically select everything
needed.

We must split exofs/Kconfig in two. The ore one is always included.
And the exofs one is left in it's old place in the menu.

[Needed for the 3.2.0 Kernel]
CC: Stable Tree <stable@kernel.org>
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2012-01-06 16:48:14 +02:00