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authorSagi Grimberg <sagig@mellanox.com>2015-09-03 19:28:23 +0300
committerJens Axboe <axboe@fb.com>2015-09-11 09:03:50 -0600
commit46348456c1791053dcbe5a9e21825b10a3c8a8fb (patch)
treea083b47153c0a53afb12e1163c92f2b2ebe741b7
parent87a816df537e096d404add543ef47b796906c130 (diff)
downloadop-kernel-dev-46348456c1791053dcbe5a9e21825b10a3c8a8fb.zip
op-kernel-dev-46348456c1791053dcbe5a9e21825b10a3c8a8fb.tar.gz
block: Copy a user iovec if it includes gaps
For drivers that don't support gaps in the SG lists handed to them we must bounce (copy the user buffers) and pass a bio that does not include gaps. This doesn't matter for any current user, but will help to allow iser which can't handle gaps to use the block virtual boundary instead of using driver-local bounce buffering when handling SG_IO commands. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Jens Axboe <axboe@fb.com>
-rw-r--r--block/blk-map.c26
1 files changed, 24 insertions, 2 deletions
diff --git a/block/blk-map.c b/block/blk-map.c
index 2338416..f565e11 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -9,6 +9,24 @@
#include "blk.h"
+static bool iovec_gap_to_prv(struct request_queue *q,
+ struct iovec *prv, struct iovec *cur)
+{
+ unsigned long prev_end;
+
+ if (!queue_virt_boundary(q))
+ return false;
+
+ if (prv->iov_base == NULL && prv->iov_len == 0)
+ /* prv is not set - don't check */
+ return false;
+
+ prev_end = (unsigned long)(prv->iov_base + prv->iov_len);
+
+ return (((unsigned long)cur->iov_base & queue_virt_boundary(q)) ||
+ prev_end & queue_virt_boundary(q));
+}
+
int blk_rq_append_bio(struct request_queue *q, struct request *rq,
struct bio *bio)
{
@@ -67,7 +85,7 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
struct bio *bio;
int unaligned = 0;
struct iov_iter i;
- struct iovec iov;
+ struct iovec iov, prv = {.iov_base = NULL, .iov_len = 0};
if (!iter || !iter->count)
return -EINVAL;
@@ -81,8 +99,12 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
/*
* Keep going so we check length of all segments
*/
- if (uaddr & queue_dma_alignment(q))
+ if ((uaddr & queue_dma_alignment(q)) ||
+ iovec_gap_to_prv(q, &prv, &iov))
unaligned = 1;
+
+ prv.iov_base = iov.iov_base;
+ prv.iov_len = iov.iov_len;
}
if (unaligned || (q->dma_pad_mask & iter->count) || map_data)
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