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authorMike Snitzer <snitzer@redhat.com>2012-12-21 20:23:36 +0000
committerAlasdair G Kergon <agk@redhat.com>2012-12-21 20:23:36 +0000
commitd54eaa5a0fde0a202e4e91f200f818edcef15bee (patch)
treebb40893166dc8cd1d0f84c8087d021b66774a007 /include/linux/device-mapper.h
parent9c5091f2eeeffe5eca2ffe8a1bc28d312c8a5083 (diff)
dm: prepare to support WRITE SAME
Allow targets to opt in to WRITE SAME support by setting 'num_write_same_requests' in the dm_target structure. A dm device will only advertise WRITE SAME support if all its targets and all its underlying devices support it. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'include/linux/device-mapper.h')
-rw-r--r--include/linux/device-mapper.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 38d27a10aa5d..d1f6cd8486f2 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -205,6 +205,11 @@ struct dm_target {
*/
unsigned num_discard_requests;
+ /*
+ * The number of WRITE SAME requests that will be submitted to the target.
+ */
+ unsigned num_write_same_requests;
+
/* target specific data */
void *private;