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authorLinus Torvalds <torvalds@linux-foundation.org>2014-03-07 15:17:36 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-03-07 15:17:36 -0800
commit2ef176f11a40d21e8d6c5d98a3c09d57c861fac6 (patch)
treebfac92c332d83f77a97514648e8b45b096d2a35c /Documentation/device-mapper/cache.txt
parentb053940df41808f0f27568eb36820d10a8a987f8 (diff)
parentcebc2de44d3bce53e46476e774126c298ca2c8a9 (diff)
Merge tag 'dm-3.14-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fixes from Mike Snitzer: - dm-cache memory allocation failure fix - fix DM's Kconfig identation - dm-snapshot metadata corruption fix for bug introduced in 3.14-rc1 - important refcount < 0 fix for the DM persistent data library's space map metadata interface which fixes corruption reported by a few dm-thinp users and last but not least: - more extensive fixes than ideal for dm-thinp's data resize capability (which has had growing pain much like we've seen from -ENOSPC handling of filesystems that mature). The end result is dm-thinp now handles metadata operation failure and no data space error conditions much better than before. * tag 'dm-3.14-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm space map metadata: fix refcount decrement below 0 which caused corruption dm thin: fix Documentation for held metadata root feature dm thin: fix noflush suspend IO queueing dm thin: fix deadlock in __requeue_bio_list dm thin: fix out of data space handling dm thin: ensure user takes action to validate data and metadata consistency dm thin: synchronize the pool mode during suspend dm snapshot: fix metadata corruption dm: fix Kconfig indentation dm cache mq: fix memory allocation failure for large cache devices
Diffstat (limited to 'Documentation/device-mapper/cache.txt')
-rw-r--r--Documentation/device-mapper/cache.txt11
1 files changed, 5 insertions, 6 deletions
diff --git a/Documentation/device-mapper/cache.txt b/Documentation/device-mapper/cache.txt
index e6b72d35515..68c0f517c60 100644
--- a/Documentation/device-mapper/cache.txt
+++ b/Documentation/device-mapper/cache.txt
@@ -124,12 +124,11 @@ the default being 204800 sectors (or 100MB).
Updating on-disk metadata
-------------------------
-On-disk metadata is committed every time a REQ_SYNC or REQ_FUA bio is
-written. If no such requests are made then commits will occur every
-second. This means the cache behaves like a physical disk that has a
-write cache (the same is true of the thin-provisioning target). If
-power is lost you may lose some recent writes. The metadata should
-always be consistent in spite of any crash.
+On-disk metadata is committed every time a FLUSH or FUA bio is written.
+If no such requests are made then commits will occur every second. This
+means the cache behaves like a physical disk that has a volatile write
+cache. If power is lost you may lose some recent writes. The metadata
+should always be consistent in spite of any crash.
The 'dirty' state for a cache block changes far too frequently for us
to keep updating it on the fly. So we treat it as a hint. In normal