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authorDavid Teigland <teigland@redhat.com>2006-06-26 00:27:33 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 09:58:36 -0700
commitc2ade42dd35466d90aa6fc7cc717f396e165492f (patch)
tree245baeabfea43a3b2654adb962e776a877da0059
parent17b2f66f2a39a4e4d1ed456f35ee3bb598e41d35 (diff)
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[PATCH] dm: create error table
Add a library function dm_create_error_table() to create a table that rejects any I/O sent to a device with EIO. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--drivers/md/dm-table.c38
-rw-r--r--include/linux/device-mapper.h6
2 files changed, 44 insertions, 0 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 10c9439635c..827b648fac5 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -237,6 +237,44 @@ int dm_table_create(struct dm_table **result, int mode,
return 0;
}
+int dm_create_error_table(struct dm_table **result, struct mapped_device *md)
+{
+ struct dm_table *t;
+ sector_t dev_size = 1;
+ int r;
+
+ /*
+ * Find current size of device.
+ * Default to 1 sector if inactive.
+ */
+ t = dm_get_table(md);
+ if (t) {
+ dev_size = dm_table_get_size(t);
+ dm_table_put(t);
+ }
+
+ r = dm_table_create(&t, FMODE_READ, 1, md);
+ if (r)
+ return r;
+
+ r = dm_table_add_target(t, "error", 0, dev_size, NULL);
+ if (r)
+ goto out;
+
+ r = dm_table_complete(t);
+ if (r)
+ goto out;
+
+ *result = t;
+
+out:
+ if (r)
+ dm_table_put(t);
+
+ return r;
+}
+EXPORT_SYMBOL_GPL(dm_create_error_table);
+
static void free_devices(struct list_head *devices)
{
struct list_head *tmp, *next;
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 010c8c5eeb3..61103d2bc24 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -227,5 +227,11 @@ void dm_table_event(struct dm_table *t);
*/
int dm_swap_table(struct mapped_device *md, struct dm_table *t);
+/*
+ * Prepare a table for a device that will error all I/O.
+ * To make it active, call dm_suspend(), dm_swap_table() then dm_resume().
+ */
+int dm_create_error_table(struct dm_table **result, struct mapped_device *md);
+
#endif /* __KERNEL__ */
#endif /* _LINUX_DEVICE_MAPPER_H */