block: Replace SG_GAPS with new queue limits mask
The SG_GAPS queue flag caused checks for bio vector alignment against
PAGE_SIZE, but the device may have different constraints. This patch
adds a queue limits so a driver with such constraints can set to allow
requests that would have been unnecessarily split. The new gaps check
takes the request_queue as a parameter to simplify the logic around
invoking this function.
This new limit makes the queue flag redundant, so removing it and
all usage. Device-mappers will inherit the correct settings through
blk_stack_limits().
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/bio.h b/include/linux/bio.h
index ad72174..b9b6e04 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -187,15 +187,6 @@
__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
/*
- * Check if adding a bio_vec after bprv with offset would create a gap in
- * the SG list. Most drivers don't care about this, but some do.
- */
-static inline bool bvec_gap_to_prev(struct bio_vec *bprv, unsigned int offset)
-{
- return offset || ((bprv->bv_offset + bprv->bv_len) & (PAGE_SIZE - 1));
-}
-
-/*
* drivers should _never_ use the all version - the bio may have been split
* before it got to the driver and the driver won't own all of it
*/
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e427deb..a622f27 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -250,6 +250,7 @@
struct queue_limits {
unsigned long bounce_pfn;
unsigned long seg_boundary_mask;
+ unsigned long virt_boundary_mask;
unsigned int max_hw_sectors;
unsigned int chunk_sectors;
@@ -479,7 +480,6 @@
#define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */
#define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */
#define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/
-#define QUEUE_FLAG_SG_GAPS 22 /* queue doesn't support SG gaps */
#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
(1 << QUEUE_FLAG_STACKABLE) | \
@@ -981,6 +981,7 @@
void *buf, unsigned int size);
extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
+extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
extern void blk_queue_dma_alignment(struct request_queue *, int);
@@ -1149,6 +1150,11 @@
return q->limits.seg_boundary_mask;
}
+static inline unsigned long queue_virt_boundary(struct request_queue *q)
+{
+ return q->limits.virt_boundary_mask;
+}
+
static inline unsigned int queue_max_sectors(struct request_queue *q)
{
return q->limits.max_sectors;
@@ -1349,6 +1355,19 @@
page_cache_release(p.v);
}
+/*
+ * Check if adding a bio_vec after bprv with offset would create a gap in
+ * the SG list. Most drivers don't care about this, but some do.
+ */
+static inline bool bvec_gap_to_prev(struct request_queue *q,
+ struct bio_vec *bprv, unsigned int offset)
+{
+ if (!queue_virt_boundary(q))
+ return false;
+ return offset ||
+ ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
+}
+
struct work_struct;
int kblockd_schedule_work(struct work_struct *work);
int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);