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authorAlasdair G Kergon <agk@redhat.com>2011-11-01 00:19:02 +0400
committerAlasdair G Kergon <agk@redhat.com>2011-11-01 00:19:02 +0400
commitcc6cbe141a20f6d876b161b60af38d93935bfa85 (patch)
tree82fbbc48815503683b434c74b7eb18c15960f4f9 /include/linux/device-mapper.h
parent3791e2fc0e4b40d4188e79b0a99bfa6bce714a10 (diff)
downloadlinux-cc6cbe141a20f6d876b161b60af38d93935bfa85.tar.xz
dm table: add always writeable feature
Add a target feature flag DM_TARGET_ALWAYS_WRITEABLE to indicate that a target does not support read-only mode. The initial implementation of the thin provisioning target uses this. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'include/linux/device-mapper.h')
-rw-r--r--include/linux/device-mapper.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 294e78a7fccd..cc58e2d7c032 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -166,6 +166,13 @@ struct target_type {
#define DM_TARGET_SINGLETON 0x00000001
#define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON)
+/*
+ * Indicates that a target does not support read-only devices.
+ */
+#define DM_TARGET_ALWAYS_WRITEABLE 0x00000002
+#define dm_target_always_writeable(type) \
+ ((type)->features & DM_TARGET_ALWAYS_WRITEABLE)
+
struct dm_target {
struct dm_table *table;
struct target_type *type;