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Commit c2ade42d authored by David Teigland's avatar David Teigland Committed by Linus Torvalds
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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: default avatarAlasdair G Kergon <agk@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 17b2f66f

drivers/md/dm-table.c

+38 −0
Original line number Diff line number Diff line
@@ -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;

include/linux/device-mapper.h

+6 −0
Original line number Diff line number Diff line
@@ -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 */