Commit cc6cbe14 authored by Alasdair G Kergon's avatar Alasdair G Kergon

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: default avatarAlasdair G Kergon <agk@redhat.com>
parent 3791e2fc
...@@ -774,6 +774,12 @@ int dm_table_add_target(struct dm_table *t, const char *type, ...@@ -774,6 +774,12 @@ int dm_table_add_target(struct dm_table *t, const char *type,
t->singleton = 1; t->singleton = 1;
} }
if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
DMERR("%s: target type %s may not be included in read-only tables",
dm_device_name(t->md), type);
return -EINVAL;
}
tgt->table = t; tgt->table = t;
tgt->begin = start; tgt->begin = start;
tgt->len = len; tgt->len = len;
......
...@@ -166,6 +166,13 @@ struct target_type { ...@@ -166,6 +166,13 @@ struct target_type {
#define DM_TARGET_SINGLETON 0x00000001 #define DM_TARGET_SINGLETON 0x00000001
#define dm_target_needs_singleton(type) ((type)->features & DM_TARGET_SINGLETON) #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_target {
struct dm_table *table; struct dm_table *table;
struct target_type *type; struct target_type *type;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment