forked from Minki/linux
3418d036c8
Implement the calculation of partial parity for a stripe and PPL write logging functionality. The description of PPL is added to the documentation. More details can be found in the comments in raid5-ppl.c. Attach a page for holding the partial parity data to stripe_head. Allocate it only if mddev has the MD_HAS_PPL flag set. Partial parity is the xor of not modified data chunks of a stripe and is calculated as follows: - reconstruct-write case: xor data from all not updated disks in a stripe - read-modify-write case: xor old data and parity from all updated disks in a stripe Implement it using the async_tx API and integrate into raid_run_ops(). It must be called when we still have access to old data, so do it when STRIPE_OP_BIODRAIN is set, but before ops_run_prexor5(). The result is stored into sh->ppl_page. Partial parity is not meaningful for full stripe write and is not stored in the log or used for recovery, so don't attempt to calculate it when stripe has STRIPE_FULL_WRITE. Put the PPL metadata structures to md_p.h because userspace tools (mdadm) will also need to read/write PPL. Warn about using PPL with enabled disk volatile write-back cache for now. It can be removed once disk cache flushing before writing PPL is implemented. Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com> Signed-off-by: Shaohua Li <shli@fb.com> |
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.. | ||
bcache | ||
persistent-data | ||
bitmap.c | ||
bitmap.h | ||
dm-bio-prison.c | ||
dm-bio-prison.h | ||
dm-bio-record.h | ||
dm-bufio.c | ||
dm-bufio.h | ||
dm-builtin.c | ||
dm-cache-block-types.h | ||
dm-cache-metadata.c | ||
dm-cache-metadata.h | ||
dm-cache-policy-cleaner.c | ||
dm-cache-policy-internal.h | ||
dm-cache-policy-smq.c | ||
dm-cache-policy.c | ||
dm-cache-policy.h | ||
dm-cache-target.c | ||
dm-core.h | ||
dm-crypt.c | ||
dm-delay.c | ||
dm-era-target.c | ||
dm-exception-store.c | ||
dm-exception-store.h | ||
dm-flakey.c | ||
dm-io.c | ||
dm-ioctl.c | ||
dm-kcopyd.c | ||
dm-linear.c | ||
dm-log-userspace-base.c | ||
dm-log-userspace-transfer.c | ||
dm-log-userspace-transfer.h | ||
dm-log-writes.c | ||
dm-log.c | ||
dm-mpath.c | ||
dm-mpath.h | ||
dm-path-selector.c | ||
dm-path-selector.h | ||
dm-queue-length.c | ||
dm-raid1.c | ||
dm-raid.c | ||
dm-region-hash.c | ||
dm-round-robin.c | ||
dm-rq.c | ||
dm-rq.h | ||
dm-service-time.c | ||
dm-snap-persistent.c | ||
dm-snap-transient.c | ||
dm-snap.c | ||
dm-stats.c | ||
dm-stats.h | ||
dm-stripe.c | ||
dm-switch.c | ||
dm-sysfs.c | ||
dm-table.c | ||
dm-target.c | ||
dm-thin-metadata.c | ||
dm-thin-metadata.h | ||
dm-thin.c | ||
dm-uevent.c | ||
dm-uevent.h | ||
dm-verity-fec.c | ||
dm-verity-fec.h | ||
dm-verity-target.c | ||
dm-verity.h | ||
dm-zero.c | ||
dm.c | ||
dm.h | ||
faulty.c | ||
Kconfig | ||
linear.c | ||
linear.h | ||
Makefile | ||
md-cluster.c | ||
md-cluster.h | ||
md.c | ||
md.h | ||
multipath.c | ||
multipath.h | ||
raid0.c | ||
raid0.h | ||
raid1.c | ||
raid1.h | ||
raid5-cache.c | ||
raid5-log.h | ||
raid5-ppl.c | ||
raid5.c | ||
raid5.h | ||
raid10.c | ||
raid10.h |