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authorLinus Torvalds <torvalds@linux-foundation.org>2014-08-14 09:17:56 -0600
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-14 09:17:56 -0600
commitba368991f63f020afe4ee9d5b647c5397cf3c7f2 (patch)
tree8d391c8921acab5bd70cd04edaeb3de4c38ed426 /Documentation
parenta8e4def604a9affa04fdd4efa0692da1385ffa3f (diff)
parent200612ec33e555a356eebc717630b866ae2b694f (diff)
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op-kernel-dev-ba368991f63f020afe4ee9d5b647c5397cf3c7f2.tar.gz
Merge tag 'dm-3.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper changes from Mike Snitzer: - Allow the thin target to paired with any size external origin; also allow thin snapshots to be larger than the external origin. - Add support for quickly loading a repetitive pattern into the dm-switch target. - Use per-bio data in the dm-crypt target instead of always using a mempool for each allocation. Required switching to kmalloc alignment for the bio slab. - Fix DM core to properly stack the QUEUE_FLAG_NO_SG_MERGE flag - Fix the dm-cache and dm-thin targets' export of the minimum_io_size to match the data block size -- this fixes an issue where mkfs.xfs would improperly infer raid striping was in place on the underlying storage. - Small cleanups in dm-io, dm-mpath and dm-cache * tag 'dm-3.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm table: propagate QUEUE_FLAG_NO_SG_MERGE dm switch: efficiently support repetitive patterns dm switch: factor out switch_region_table_read dm cache: set minimum_io_size to cache's data block size dm thin: set minimum_io_size to pool's data block size dm crypt: use per-bio data block: use kmalloc alignment for bio slab dm table: make dm_table_supports_discards static dm cache metadata: use dm-space-map-metadata.h defined size limits dm cache: fail migrations in the do_worker error path dm cache: simplify deferred set reference count increments dm thin: relax external origin size constraints dm thin: switch to an atomic_t for tracking pending new block preparations dm mpath: eliminate pg_ready() wrapper dm io: simplify dec_count and sync_io
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/device-mapper/switch.txt12
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/device-mapper/switch.txt b/Documentation/device-mapper/switch.txt
index 2fa7493..8897d04 100644
--- a/Documentation/device-mapper/switch.txt
+++ b/Documentation/device-mapper/switch.txt
@@ -106,6 +106,11 @@ which paths.
The path number in the range 0 ... (<num_paths> - 1).
Expressed in hexadecimal (WITHOUT any prefix like 0x).
+R<n>,<m>
+ This parameter allows repetitive patterns to be loaded quickly. <n> and <m>
+ are hexadecimal numbers. The last <n> mappings are repeated in the next <m>
+ slots.
+
Status
======
@@ -124,3 +129,10 @@ Create a switch device with 64kB region size:
Set mappings for the first 7 entries to point to devices switch0, switch1,
switch2, switch0, switch1, switch2, switch1:
dmsetup message switch 0 set_region_mappings 0:0 :1 :2 :0 :1 :2 :1
+
+Set repetitive mapping. This command:
+ dmsetup message switch 0 set_region_mappings 1000:1 :2 R2,10
+is equivalent to:
+ dmsetup message switch 0 set_region_mappings 1000:1 :2 :1 :2 :1 :2 :1 :2 \
+ :1 :2 :1 :2 :1 :2 :1 :2 :1 :2
+
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