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authorMartin K. Petersen <martin.petersen@oracle.com>2009-11-10 11:50:21 +0100
committerJens Axboe <jens.axboe@oracle.com>2009-11-10 11:50:21 +0100
commit86b37281411cf1e9bc0a6b5406c45edb7bd9ea5d (patch)
tree729db57dd52054af1bc16b4afb131093dfc9d255 /include/linux
parentcf7c25cf91f632a3528669fc0876e1fc8355ff9b (diff)
block: Expose discard granularity
While SSDs track block usage on a per-sector basis, RAID arrays often have allocation blocks that are bigger. Allow the discard granularity and alignment to be set and teach the topology stacking logic how to handle them. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/blkdev.h18
-rw-r--r--include/linux/genhd.h1
2 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 39c601f783a..1cc02972fbe 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -312,12 +312,15 @@ struct queue_limits {
unsigned int io_min;
unsigned int io_opt;
unsigned int max_discard_sectors;
+ unsigned int discard_granularity;
+ unsigned int discard_alignment;
unsigned short logical_block_size;
unsigned short max_hw_segments;
unsigned short max_phys_segments;
unsigned char misaligned;
+ unsigned char discard_misaligned;
unsigned char no_cluster;
};
@@ -1121,6 +1124,21 @@ static inline int bdev_alignment_offset(struct block_device *bdev)
return q->limits.alignment_offset;
}
+static inline int queue_discard_alignment(struct request_queue *q)
+{
+ if (q->limits.discard_misaligned)
+ return -1;
+
+ return q->limits.discard_alignment;
+}
+
+static inline int queue_sector_discard_alignment(struct request_queue *q,
+ sector_t sector)
+{
+ return ((sector << 9) - q->limits.discard_alignment)
+ & (q->limits.discard_granularity - 1);
+}
+
static inline int queue_dma_alignment(struct request_queue *q)
{
return q ? q->dma_alignment : 511;
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 297df45ffd0..c6c0c41af35 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -91,6 +91,7 @@ struct hd_struct {
sector_t start_sect;
sector_t nr_sects;
sector_t alignment_offset;
+ unsigned int discard_alignment;
struct device __dev;
struct kobject *holder_dir;
int policy, partno;