NeilBrown 67f455486d md/raid56: Don't perform reads to support writes until stripe is ready. ... If it is found that we need to pre-read some blocks before a write can succeed, we normally set STRIPE_DELAYED and don't actually perform the read until STRIPE_PREREAD_ACTIVE subsequently gets set. However for a degraded RAID6 we currently perform the reads as soon as we see that a write is pending. This significantly hurts throughput. So: - when handle_stripe_dirtying find a block that it wants on a device that is failed, set STRIPE_DELAY, instead of doing nothing, and - when fetch_block detects that a read might be required to satisfy a write, only perform the read if STRIPE_PREREAD_ACTIVE is set, and if we would actually need to read something to complete the write. This also helps RAID5, though less often as RAID5 supports a read-modify-write cycle. For RAID5 the read is performed too early only if the write is not a full 4K aligned write (i.e. no an R5_OVERWRITE). Also clean up a couple of horrible bits of formatting. Reported-by: Patrik Horník <patrik@dsl.sk> Signed-off-by: NeilBrown <neilb@suse.de>		2014-05-29 16:59:46 +10:00
..
bcache	bcache: remove nested function usage	2014-03-18 12:39:28 -07:00
persistent-data	dm transaction manager: fix corruption due to non-atomic transaction commit	2014-03-27 16:56:23 -04:00
bitmap.c	md/bitmap: don't abuse i_writecount for bitmap files.	2014-04-09 12:26:59 +10:00
bitmap.h	kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordingly	2013-12-11 15:28:36 -08:00
dm-bio-prison.c	dm: add cache target	2013-03-01 22:45:51 +00:00
dm-bio-prison.h	dm: add cache target	2013-03-01 22:45:51 +00:00
dm-bio-record.h	dm: Refactor for new bio cloning/splitting	2013-11-23 22:33:55 -08:00
dm-bufio.c	Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block	2014-01-30 11:19:05 -08:00
dm-bufio.h	dm snapshot: use dm-bufio prefetch	2014-01-14 23:23:03 -05:00
dm-builtin.c	dm sysfs: fix a module unload race	2014-01-14 23:23:04 -05:00
dm-cache-block-types.h	dm cache: remove remainder of distinct discard block size	2014-03-27 16:56:23 -04:00
dm-cache-metadata.c	dm cache: fix a lock-inversion	2014-04-04 14:53:05 -04:00
dm-cache-metadata.h	dm cache: fix a lock-inversion	2014-04-04 14:53:05 -04:00
dm-cache-policy-cleaner.c	dm cache: policy change version from string to integer set	2013-03-20 17:21:27 +00:00
dm-cache-policy-internal.h	dm cache: add remove_cblock method to policy interface	2013-11-11 11:37:50 -05:00
dm-cache-policy-mq.c	dm cache mq: fix memory allocation failure for large cache devices	2014-02-28 12:18:29 -05:00
dm-cache-policy.c	dm cache: add policy name to status output	2014-01-16 13:44:11 -05:00
dm-cache-policy.h	dm cache: add policy name to status output	2014-01-16 13:44:11 -05:00
dm-cache-target.c	dm cache: fix writethrough mode quiescing in cache_map	2014-05-01 16:14:24 -04:00
dm-crypt.c	dm crypt: fix cpu hotplug crash by removing per-cpu structure	2014-05-14 16:11:35 -04:00
dm-delay.c	Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block	2014-01-30 11:19:05 -08:00
dm-era-target.c	dm: take care to copy the space map roots before locking the superblock	2014-03-27 16:56:23 -04:00
dm-exception-store.c	dm: replace simple_strtoul	2012-07-27 15:07:59 +01:00
dm-exception-store.h
dm-flakey.c	block: Abstract out bvec iterator	2013-11-23 22:33:47 -08:00
dm-io.c	dm io: fix I/O to multiple destinations	2014-02-17 11:00:05 -05:00
dm-ioctl.c	dm: allow remove to be deferred	2013-11-09 18:20:22 -05:00
dm-kcopyd.c	dm: stop using WQ_NON_REENTRANT	2013-08-23 09:02:13 -04:00
dm-linear.c	block: Abstract out bvec iterator	2013-11-23 22:33:47 -08:00
dm-log-userspace-base.c	dm log userspace: allow mark requests to piggyback on flush requests	2014-01-21 23:46:27 -05:00
dm-log-userspace-transfer.c	connector: add portid to unicast in addition to broadcasting	2014-02-07 15:40:17 -08:00
dm-log-userspace-transfer.h
dm-log.c	dm: use memweight()	2012-07-30 17:25:16 -07:00
dm-mpath.c	dm mpath: fix lock order inconsistency in multipath_ioctl	2014-05-14 16:12:17 -04:00
dm-mpath.h
dm-path-selector.c
dm-path-selector.h
dm-queue-length.c	dm: reject trailing characters in sccanf input	2012-03-28 18:41:26 +01:00
dm-raid1.c	dm raid1: fix immutable biovec related BUG when retrying read bio	2014-02-18 10:48:57 -05:00
dm-raid.c	MD: Remember the last sync operation that was performed	2013-06-26 12:38:24 +10:00
dm-region-hash.c	block: Abstract out bvec iterator	2013-11-23 22:33:47 -08:00
dm-round-robin.c	dm: reject trailing characters in sccanf input	2012-03-28 18:41:26 +01:00
dm-service-time.c	dm: reject trailing characters in sccanf input	2012-03-28 18:41:26 +01:00
dm-snap-persistent.c	dm snapshot: fix metadata corruption	2014-03-03 17:58:13 -05:00
dm-snap-transient.c	md: Add in export.h for files using EXPORT_SYMBOL	2011-10-31 19:31:19 -04:00
dm-snap.c	Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block	2014-01-30 11:19:05 -08:00
dm-stats.c	dm stats: initialize read-only module parameter	2013-12-10 19:13:21 -05:00
dm-stats.h	dm: add statistics support	2013-09-05 20:46:06 -04:00
dm-stripe.c	block: Abstract out bvec iterator	2013-11-23 22:33:47 -08:00
dm-switch.c	block: Abstract out bvec iterator	2013-11-23 22:33:47 -08:00
dm-sysfs.c	dm sysfs: fix a module unload race	2014-01-14 23:23:04 -05:00
dm-table.c	dm table: add dm_table_run_md_queue_async	2014-03-27 16:56:24 -04:00
dm-target.c	dm: allow error target to replace bio-based and request-based targets	2013-09-05 20:46:05 -04:00
dm-thin-metadata.c	dm: take care to copy the space map roots before locking the superblock	2014-03-27 16:56:23 -04:00
dm-thin-metadata.h	dm thin: ensure user takes action to validate data and metadata consistency	2014-03-05 15:25:35 -05:00
dm-thin.c	dm thin: add timeout to stop out-of-data-space mode holding IO forever	2014-05-14 16:11:37 -04:00
dm-uevent.c	md: Add in export.h for files using EXPORT_SYMBOL	2011-10-31 19:31:19 -04:00
dm-uevent.h
dm-verity.c	dm verity: fix biovecs hash calculation regression	2014-04-15 12:19:24 -04:00
dm-zero.c	dm: rename request variables to bios	2013-03-01 22:45:47 +00:00
dm.c	dm table: add dm_table_run_md_queue_async	2014-03-27 16:56:24 -04:00
dm.h	dm table: add dm_table_run_md_queue_async	2014-03-27 16:56:24 -04:00
faulty.c	block: Abstract out bvec iterator	2013-11-23 22:33:47 -08:00
Kconfig	dm: add era target	2014-03-27 16:56:23 -04:00
linear.c	block: Introduce new bio_split()	2013-11-23 22:33:57 -08:00
linear.h
Makefile	dm: add era target	2014-03-27 16:56:23 -04:00
md.c	md: refuse to change shape of array if it is active but read-only	2014-05-29 16:59:30 +10:00
md.h	md/bitmap: don't abuse i_writecount for bitmap files.	2014-04-09 12:26:59 +10:00
multipath.c	block: Abstract out bvec iterator	2013-11-23 22:33:47 -08:00
multipath.h
raid0.c	block: Introduce new bio_split()	2013-11-23 22:33:57 -08:00
raid0.h	md: add proper merge_bvec handling to RAID0 and Linear.	2012-03-19 12:46:39 +11:00
raid1.c	md/raid1: r1buf_pool_alloc: free allocate pages when subsequent allocation fails.	2014-04-09 14:42:23 +10:00
raid1.h	raid1: Rewrite the implementation of iobarrier.	2013-11-19 15:19:18 +11:00
raid5.c	md/raid56: Don't perform reads to support writes until stripe is ready.	2014-05-29 16:59:46 +10:00
raid5.h	md update for 3.13.	2013-11-20 13:05:25 -08:00
raid10.c	md/raid10: call wait_barrier() for each request submitted.	2014-05-06 09:49:26 +10:00
raid10.h	MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1)	2013-02-26 11:55:30 +11:00