linux/drivers/md
Joe Thornber 2ee57d5873 dm cache: add passthrough mode
"Passthrough" is a dm-cache operating mode (like writethrough or
writeback) which is intended to be used when the cache contents are not
known to be coherent with the origin device.  It behaves as follows:

* All reads are served from the origin device (all reads miss the cache)
* All writes are forwarded to the origin device; additionally, write
  hits cause cache block invalidates

This mode decouples cache coherency checks from cache device creation,
largely to avoid having to perform coherency checks while booting.  Boot
scripts can create cache devices in passthrough mode and put them into
service (mount cached filesystems, for example) without having to worry
about coherency.  Coherency that exists is maintained, although the
cache will gradually cool as writes take place.

Later, applications can perform coherency checks, the nature of which
will depend on the type of the underlying storage.  If coherency can be
verified, the cache device can be transitioned to writethrough or
writeback mode while still warm; otherwise, the cache contents can be
discarded prior to transitioning to the desired operating mode.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Morgan Mears <Morgan.Mears@netapp.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-11 11:37:49 -05:00
..
bcache bcache: Fix a null ptr deref regression 2013-10-10 18:17:39 -07:00
persistent-data dm space map disk: optimise sm_disk_dec_block 2013-11-09 18:20:24 -05:00
bitmap.c md: replace strict_strto*() with kstrto*() 2013-06-14 08:10:26 +10:00
bitmap.h md/bitmap: record the space available for the bitmap in the superblock. 2012-05-22 13:55:34 +10:00
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-bufio.c drivers: convert shrinkers to new count/scan API 2013-09-10 18:56:32 -04:00
dm-bufio.h dm bufio: prefetch 2012-03-28 18:41:29 +01:00
dm-cache-block-types.h dm: add cache target 2013-03-01 22:45:51 +00:00
dm-cache-metadata.c dm cache: add passthrough mode 2013-11-11 11:37:49 -05:00
dm-cache-metadata.h dm cache: add passthrough mode 2013-11-11 11:37:49 -05:00
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 policy: remove return from void policy_remove_mapping 2013-11-09 18:20:16 -05:00
dm-cache-policy-mq.c dm cache: be much more aggressive about promoting writes to discarded blocks 2013-11-09 18:20:25 -05:00
dm-cache-policy.c dm cache: return -EINVAL if the user specifies unknown cache policy 2013-11-09 18:20:18 -05:00
dm-cache-policy.h dm cache policy: fix description of lookup fn 2013-05-10 14:37:17 +01:00
dm-cache-target.c dm cache: add passthrough mode 2013-11-11 11:37:49 -05:00
dm-crypt.c dm crypt: add TCW IV mode for old CBC TCRYPT containers 2013-11-09 18:20:20 -05:00
dm-delay.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-exception-store.c dm: replace simple_strtoul 2012-07-27 15:07:59 +01:00
dm-exception-store.h
dm-flakey.c dm flakey: correct ctr alloc failure mesg 2013-07-10 23:41:17 +01:00
dm-io.c dm: add reserved_bio_based_ios module parameter 2013-09-23 10:42:24 -04:00
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 dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-log-userspace-base.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
dm-log-userspace-transfer.c connector/userns: replace netlink uses of cap_raised() with capable() 2012-05-10 23:21:39 -04:00
dm-log-userspace-transfer.h
dm-log.c dm: use memweight() 2012-07-30 17:25:16 -07:00
dm-mpath.c dm mpath: requeue I/O during pg_init 2013-11-05 11:20:34 -05:00
dm-mpath.h
dm-path-selector.c md: Add module.h to all files using it implicitly 2011-10-31 19:31:18 -04:00
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: stop using WQ_NON_REENTRANT 2013-08-23 09:02:13 -04:00
dm-raid.c MD: Remember the last sync operation that was performed 2013-06-26 12:38:24 +10:00
dm-region-hash.c dm raid1: fix crash with mirror recovery and discard 2012-07-20 14:25:03 +01:00
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: workaround for a false positive lockdep warning 2013-09-20 10:36:34 -04:00
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 dm-snapshot: fix performance degradation due to small hash size 2013-09-20 10:36:34 -04:00
dm-stats.c dm stats: fix possible counter corruption on 32-bit systems 2013-09-18 14:41:06 -04:00
dm-stats.h dm: add statistics support 2013-09-05 20:46:06 -04:00
dm-stripe.c dm stripe: silence a couple sparse warnings 2013-09-06 11:36:01 -04:00
dm-switch.c dm: add switch target 2013-07-10 23:41:19 +01:00
dm-sysfs.c
dm-table.c dm table: print error on preresume failure 2013-11-09 18:20:21 -05:00
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 thin: generate event when metadata threshold passed 2013-05-10 14:37:21 +01:00
dm-thin-metadata.h dm thin: generate event when metadata threshold passed 2013-05-10 14:37:21 +01:00
dm-thin.c dm thin: do not expose non-zero discard limits if discards disabled 2013-09-23 10:42:06 -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: use __ffs and __fls 2013-07-10 23:41:17 +01:00
dm-zero.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm.c dm: allow remove to be deferred 2013-11-09 18:20:22 -05:00
dm.h dm: allow remove to be deferred 2013-11-09 18:20:22 -05:00
faulty.c block: Add bio_end_sector() 2013-03-23 14:15:29 -07:00
Kconfig dm: fix Kconfig menu indentation 2013-11-09 18:20:22 -05:00
linear.c block: Add bio_end_sector() 2013-03-23 14:15:29 -07:00
linear.h md/linear: typedef removal: linear_conf_t -> struct linear_conf 2011-10-11 16:48:54 +11:00
Makefile dm: add statistics support 2013-09-05 20:46:06 -04:00
md.c md: avoid deadlock when dirty buffers during md_stop. 2013-08-27 16:45:00 +10:00
md.h md: avoid deadlock when dirty buffers during md_stop. 2013-08-27 16:45:00 +10:00
multipath.c MD: change the parameter of md thread 2012-10-11 13:34:00 +11:00
multipath.h md/multipath: typedef removal: multipath_conf_t -> struct mpconf 2011-10-11 16:48:57 +11:00
raid0.c md: fix buglet in RAID5 -> RAID0 conversion. 2013-06-26 12:38:19 +10:00
raid0.h md: add proper merge_bvec handling to RAID0 and Linear. 2012-03-19 12:46:39 +11:00
raid1.c md/raid1: fix bio handling problems in process_checks() 2013-07-18 14:18:04 +10:00
raid1.h md/raid1: prevent merging too large request 2012-07-31 10:03:53 +10:00
raid5.c raid5: only wakeup necessary threads 2013-09-02 10:31:29 +10:00
raid5.h raid5: only wakeup necessary threads 2013-09-02 10:31:29 +10:00
raid10.c md/raid10: remove use-after-free bug. 2013-07-25 16:46:53 +10:00
raid10.h MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1) 2013-02-26 11:55:30 +11:00