Tomasz Majchrzak 1532d9e87e raid5-ppl: PPL support for disks with write-back cache enabled ... In order to provide data consistency with PPL for disks with write-back cache enabled all data has to be flushed to disks before next PPL entry. The disks to be flushed are marked in the bitmap. It's modified under a mutex and it's only read after PPL io unit is submitted. A limitation of 64 disks in the array has been introduced to keep data structures and implementation simple. RAID5 arrays with so many disks are not likely due to high risk of multiple disks failure. Such restriction should not be a real life limitation. With write-back cache disabled next PPL entry is submitted when data write for current one completes. Data flush defers next log submission so trigger it when there are no stripes for handling found. As PPL assures all data is flushed to disk at request completion, just acknowledge flush request when PPL is enabled. Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com> Signed-off-by: Shaohua Li <sh.li@alibaba-inc.com>		2018-01-15 14:29:42 -08:00
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md-cluster.txt	md-cluster: update document for raid10	2017-11-01 21:32:25 -07:00
raid5-cache.txt	MD: add doc for raid5-cache	2017-02-13 09:17:54 -08:00
raid5-ppl.txt	raid5-ppl: PPL support for disks with write-back cache enabled	2018-01-15 14:29:42 -08:00