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/device-mapper.h') 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 v1.2.3 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/device-mapper.h') 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 v1.2.3 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/device-mapper.h') 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 v1.2.3