From a5664dad7e1a278d2915c2bf79cf42250e12d7db Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Thu, 12 Aug 2010 04:14:01 +0100 Subject: dm ioctl: make bio or request based device type immutable Determine whether a mapped device is bio-based or request-based when loading its first (inactive) table and don't allow that to be changed later. This patch performs different device initialisation in each of the two cases. (We don't think it's necessary to add code to support changing between the two types.) Allowed md->type transitions: DM_TYPE_NONE to DM_TYPE_BIO_BASED DM_TYPE_NONE to DM_TYPE_REQUEST_BASED We now prevent table_load from replacing the inactive table with a conflicting type of table even after an explicit table_clear. Introduce 'type_lock' into the struct mapped_device to protect md->type and to prepare for the next patch that will change the queue initialization and allocate memory while md->type_lock is held. Signed-off-by: Mike Snitzer Acked-by: Kiyoshi Ueda Signed-off-by: Alasdair G Kergon drivers/md/dm-ioctl.c | 15 +++++++++++++++ drivers/md/dm.c | 37 ++++++++++++++++++++++++++++++------- drivers/md/dm.h | 5 +++++ include/linux/dm-ioctl.h | 4 ++-- 4 files changed, 52 insertions(+), 9 deletions(-) --- include/linux/dm-ioctl.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h index 2c445e113790..43b2de17449b 100644 --- a/include/linux/dm-ioctl.h +++ b/include/linux/dm-ioctl.h @@ -266,9 +266,9 @@ enum { #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) #define DM_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 17 +#define DM_VERSION_MINOR 18 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2010-03-05)" +#define DM_VERSION_EXTRA "-ioctl (2010-06-29)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */ -- cgit v1.2.2 From 57cba5d3658d9fdc019c6af14a2d80aefa651e56 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Thu, 12 Aug 2010 04:14:04 +0100 Subject: dm: rename map_info flush_request to target_request_nr 'target_request_nr' is a more generic name that reflects the fact that it will be used for both flush and discard support. Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- include/linux/device-mapper.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 1381cd97b4ed..531a6f2635ae 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -22,7 +22,7 @@ typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t; union map_info { void *ptr; unsigned long long ll; - unsigned flush_request; + unsigned target_request_nr; }; /* @@ -174,7 +174,7 @@ struct dm_target { * A number of zero-length barrier requests that will be submitted * to the target for the purpose of flushing cache. * - * The request number will be placed in union map_info->flush_request. + * The request number will be placed in union map_info->target_request_nr. * It is a responsibility of the target driver to remap these requests * to the real underlying devices. */ -- cgit v1.2.2 From 7e507eb6432afdd798d4c6dccf949b8c43ef151c Mon Sep 17 00:00:00 2001 From: Peter Rajnoha Date: Thu, 12 Aug 2010 04:14:05 +0100 Subject: dm: allow autoloading of dm mod Add devname:mapper/control and MAPPER_CTRL_MINOR module alias to support dm-mod module autoloading. Signed-off-by: Kay Sievers Signed-off-by: Peter Rajnoha Signed-off-by: Alasdair G Kergon --- include/linux/dm-ioctl.h | 1 + include/linux/miscdevice.h | 1 + 2 files changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h index 43b2de17449b..49eab360d5d4 100644 --- a/include/linux/dm-ioctl.h +++ b/include/linux/dm-ioctl.h @@ -11,6 +11,7 @@ #include #define DM_DIR "mapper" /* Slashes not supported */ +#define DM_CONTROL_NODE "control" #define DM_MAX_TYPE_NAME 16 #define DM_NAME_LEN 128 #define DM_UUID_LEN 129 diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h index f6c9b7dcb9fd..bafffc737903 100644 --- a/include/linux/miscdevice.h +++ b/include/linux/miscdevice.h @@ -38,6 +38,7 @@ #define KVM_MINOR 232 #define BTRFS_MINOR 234 #define AUTOFS_MINOR 235 +#define MAPPER_CTRL_MINOR 236 #define MISC_DYNAMIC_MINOR 255 struct device; -- cgit v1.2.2 From 5ae89a8720c28caf35c4e53711d77df2856c404e Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Thu, 12 Aug 2010 04:14:08 +0100 Subject: dm: linear support discard Allow discards to be passed through to linear mappings if at least one underlying device supports it. Discards will be forwarded only to devices that support them. A target that supports discards should set num_discard_requests to indicate how many times each discard request must be submitted to it. Verify table's underlying devices support discards prior to setting the associated DM device as capable of discards (via QUEUE_FLAG_DISCARD). Signed-off-by: Mike Snitzer Signed-off-by: Mikulas Patocka Reviewed-by: Joe Thornber Signed-off-by: Alasdair G Kergon --- include/linux/device-mapper.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 531a6f2635ae..751ce21dea7b 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -180,6 +180,12 @@ struct dm_target { */ unsigned num_flush_requests; + /* + * The number of discard requests that will be submitted to the + * target. map_info->request_nr is used just like num_flush_requests. + */ + unsigned num_discard_requests; + /* target specific data */ void *private; -- cgit v1.2.2 From 56a67df766039666f61fb15b079f713e44a735ae Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Thu, 12 Aug 2010 04:14:10 +0100 Subject: dm: factor out max_io_len_target_boundary Split max_io_len_target_boundary out of max_io_len so that the discard support can make use of it without duplicating max_io_len code. Avoiding max_io_len's split_io logic enables DM's discard support to submit the entire discard request to a target. But discards must still be split on target boundaries. Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- include/linux/device-mapper.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 751ce21dea7b..2970022faa63 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -398,6 +398,12 @@ void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size); #define dm_array_too_big(fixed, obj, num) \ ((num) > (UINT_MAX - (fixed)) / (obj)) +/* + * Sector offset taken relative to the start of the target instead of + * relative to the start of the device. + */ +#define dm_target_offset(ti, sector) ((sector) - (ti)->begin) + static inline sector_t to_sector(unsigned long n) { return (n >> SECTOR_SHIFT); -- cgit v1.2.2