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authorLinus Torvalds <torvalds@linux-foundation.org>2017-02-21 12:11:41 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-21 12:11:41 -0800
commit7a771ceac771d009f7203c40b256b0608d7ea2f8 (patch)
tree940260bccb165f47669397515c00900629c01803 /Documentation/device-mapper/dm-raid.txt
parentMerge tag 'mmc-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc (diff)
parentdm: flush queued bios when process blocks to avoid deadlock (diff)
downloadlinux-dev-7a771ceac771d009f7203c40b256b0608d7ea2f8.tar.xz
linux-dev-7a771ceac771d009f7203c40b256b0608d7ea2f8.zip
Merge tag 'dm-4.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer: - Fix dm-raid transient device failure processing and other smaller tweaks. - Add journal support to the DM raid target to close the 'write hole' on raid 4/5/6. - Fix dm-cache corruption, due to rounding bug, when cache exceeds 2TB. - Add 'metadata2' feature to dm-cache to separate the dirty bitset out from other cache metadata. This improves speed of shutting down a large cache device (which implies writing out dirty bits). - Fix a memory leak during dm-stats data structure destruction. - Fix a DM multipath round-robin path selector performance regression that was caused by less precise balancing across all paths. - Lastly, introduce a DM core fix for a long-standing DM snapshot deadlock that is rooted in the complexity of the device stack used in conjunction with block core maintaining bios on current->bio_list to manage recursion in generic_make_request(). A more comprehensive fix to block core (and its hook in the cpu scheduler) would be wonderful but this DM-specific fix is pragmatic considering how difficult it has been to make progress on a generic fix. * tag 'dm-4.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (22 commits) dm: flush queued bios when process blocks to avoid deadlock dm round robin: revert "use percpu 'repeat_count' and 'current_path'" dm stats: fix a leaked s->histogram_boundaries array dm space map metadata: constify dm_space_map structures dm cache metadata: use cursor api in blocks_are_clean_separate_dirty() dm persistent data: add cursor skip functions to the cursor APIs dm cache metadata: use dm_bitset_new() to create the dirty bitset in format 2 dm bitset: add dm_bitset_new() dm cache metadata: name the cache block that couldn't be loaded dm cache metadata: add "metadata2" feature dm cache metadata: use bitset cursor api to load discard bitset dm bitset: introduce cursor api dm btree: use GFP_NOFS in dm_btree_del() dm space map common: memcpy the disk root to ensure it's arch aligned dm block manager: add unlikely() annotations on dm_bufio error paths dm cache: fix corruption seen when using cache > 2TB dm raid: cleanup awkward branching in raid_message() option processing dm raid: use mddev rather than rdev->mddev dm raid: use read_disk_sb() throughout dm raid: add raid4/5/6 journaling support ...
Diffstat (limited to 'Documentation/device-mapper/dm-raid.txt')
-rw-r--r--Documentation/device-mapper/dm-raid.txt17
1 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/device-mapper/dm-raid.txt b/Documentation/device-mapper/dm-raid.txt
index 5e3786fd9ea7..0d199353e477 100644
--- a/Documentation/device-mapper/dm-raid.txt
+++ b/Documentation/device-mapper/dm-raid.txt
@@ -161,6 +161,15 @@ The target is named "raid" and it accepts the following parameters:
the RAID type (i.e. the allocation algorithm) as well, e.g.
changing from raid5_ls to raid5_n.
+ [journal_dev <dev>]
+ This option adds a journal device to raid4/5/6 raid sets and
+ uses it to close the 'write hole' caused by the non-atomic updates
+ to the component devices which can cause data loss during recovery.
+ The journal device is used as writethrough thus causing writes to
+ be throttled versus non-journaled raid4/5/6 sets.
+ Takeover/reshape is not possible with a raid4/5/6 journal device;
+ it has to be deconfigured before requesting these.
+
<#raid_devs>: The number of devices composing the array.
Each device consists of two entries. The first is the device
containing the metadata (if any); the second is the one containing the
@@ -245,6 +254,9 @@ recovery. Here is a fuller description of the individual fields:
<data_offset> The current data offset to the start of the user data on
each component device of a raid set (see the respective
raid parameter to support out-of-place reshaping).
+ <journal_char> 'A' - active raid4/5/6 journal device.
+ 'D' - dead journal device.
+ '-' - no journal device.
Message Interface
@@ -314,3 +326,8 @@ Version History
1.9.0 Add support for RAID level takeover/reshape/region size
and set size reduction.
1.9.1 Fix activation of existing RAID 4/10 mapped devices
+1.9.2 Don't emit '- -' on the status table line in case the constructor
+ fails reading a superblock. Correctly emit 'maj:min1 maj:min2' and
+ 'D' on the status line. If '- -' is passed into the constructor, emit
+ '- -' on the table line and '-' as the status line health character.
+1.10.0 Add support for raid4/5/6 journal device