From c2ade42dd35466d90aa6fc7cc717f396e165492f Mon Sep 17 00:00:00 2001 From: David Teigland Date: Mon, 26 Jun 2006 00:27:33 -0700 Subject: [PATCH] [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/md/dm-table.c | 38 +++++++++++++++++++++++++++++++++++ include/linux/device-mapper.h | 6 ++++++ 2 files changed, 44 insertions(+) diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 10c9439635ca..827b648fac50 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 010c8c5eeb37..61103d2bc244 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 */ -- 2.39.5