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ce5d36aac2
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>
15 lines
495 B
Plaintext
15 lines
495 B
Plaintext
# ORE - Objects Raid Engine (libore.ko)
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#
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# Note ORE needs to "select ASYNC_XOR". So Not to force multiple selects
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# for every ORE user we do it like this. Any user should add itself here
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# at the "depends on EXOFS_FS || ..." with an ||. The dependencies are
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# selected here, and we default to "ON". So in effect it is like been
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# selected by any of the users.
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config ORE
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tristate
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depends on EXOFS_FS || PNFS_OBJLAYOUT
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select ASYNC_XOR
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select RAID6_PQ
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select ASYNC_PQ
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default SCSI_OSD_ULD
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