diff mbox series

[4/4] xen/blkback: move blkif_get_x86_*_req() into blkback.c

Message ID 20221216145816.27374-5-jgross@suse.com (mailing list archive)
State New, archived
Headers show
Series xen/blkback: some cleanups | expand

Commit Message

Jürgen Groß Dec. 16, 2022, 2:58 p.m. UTC 
There is no need to have the functions blkif_get_x86_32_req() and
blkif_get_x86_64_req() in a header file, as they are used in one place
only.

So move them into the using source file and drop the inline qualifier.

While at it fix some style issues, and simplify the code by variable
reusing and using min() instead of open coding it.

Instead of using barrier() use READ_ONCE() for avoiding multiple reads
of nr_segments.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 drivers/block/xen-blkback/blkback.c | 104 ++++++++++++++++++++++++++++
 drivers/block/xen-blkback/common.h  |  96 -------------------------
 2 files changed, 104 insertions(+), 96 deletions(-)

Comments

Roger Pau Monne March 14, 2023, 2 p.m. UTC | #1 
On Fri, Dec 16, 2022 at 03:58:16PM +0100, Juergen Gross wrote:
> There is no need to have the functions blkif_get_x86_32_req() and
> blkif_get_x86_64_req() in a header file, as they are used in one place
> only.
> 
> So move them into the using source file and drop the inline qualifier.
> 
> While at it fix some style issues, and simplify the code by variable
> reusing and using min() instead of open coding it.
> 
> Instead of using barrier() use READ_ONCE() for avoiding multiple reads
> of nr_segments.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
>  drivers/block/xen-blkback/blkback.c | 104 ++++++++++++++++++++++++++++
>  drivers/block/xen-blkback/common.h  |  96 -------------------------
>  2 files changed, 104 insertions(+), 96 deletions(-)
> 
> diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
> index 243712b59a05..7561fdb72c13 100644
> --- a/drivers/block/xen-blkback/blkback.c
> +++ b/drivers/block/xen-blkback/blkback.c
> @@ -1072,7 +1072,111 @@ static void end_block_io_op(struct bio *bio)
>  	bio_put(bio);
>  }
>  
> +static void blkif_get_x86_32_req(struct blkif_request *dst,
> +				 struct blkif_x86_32_request *src)

src can be const.

> +{
> +	int i, n;

Could we also take the opportunity to convert i and n to unsigned?

With that:

Acked-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks, Roger.
diff mbox series

Patch

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 243712b59a05..7561fdb72c13 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -1072,7 +1072,111 @@  static void end_block_io_op(struct bio *bio)
 	bio_put(bio);
 }
 
+static void blkif_get_x86_32_req(struct blkif_request *dst,
+				 struct blkif_x86_32_request *src)
+{
+	int i, n;
+
+	dst->operation = READ_ONCE(src->operation);
+
+	switch (dst->operation) {
+	case BLKIF_OP_READ:
+	case BLKIF_OP_WRITE:
+	case BLKIF_OP_WRITE_BARRIER:
+	case BLKIF_OP_FLUSH_DISKCACHE:
+		dst->u.rw.nr_segments = READ_ONCE(src->u.rw.nr_segments);
+		dst->u.rw.handle = src->u.rw.handle;
+		dst->u.rw.id = src->u.rw.id;
+		dst->u.rw.sector_number = src->u.rw.sector_number;
+		n = min_t(int, BLKIF_MAX_SEGMENTS_PER_REQUEST,
+			  dst->u.rw.nr_segments);
+		for (i = 0; i < n; i++)
+			dst->u.rw.seg[i] = src->u.rw.seg[i];
+		break;
+
+	case BLKIF_OP_DISCARD:
+		dst->u.discard.flag = src->u.discard.flag;
+		dst->u.discard.id = src->u.discard.id;
+		dst->u.discard.sector_number = src->u.discard.sector_number;
+		dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
+		break;
+
+	case BLKIF_OP_INDIRECT:
+		dst->u.indirect.indirect_op = src->u.indirect.indirect_op;
+		dst->u.indirect.nr_segments =
+			READ_ONCE(src->u.indirect.nr_segments);
+		dst->u.indirect.handle = src->u.indirect.handle;
+		dst->u.indirect.id = src->u.indirect.id;
+		dst->u.indirect.sector_number = src->u.indirect.sector_number;
+		n = min(MAX_INDIRECT_PAGES,
+			INDIRECT_PAGES(dst->u.indirect.nr_segments));
+		for (i = 0; i < n; i++)
+			dst->u.indirect.indirect_grefs[i] =
+				src->u.indirect.indirect_grefs[i];
+		break;
+
+	default:
+		/*
+		 * Don't know how to translate this op. Only get the
+		 * ID so failure can be reported to the frontend.
+		 */
+		dst->u.other.id = src->u.other.id;
+		break;
+	}
+}
 
+static void blkif_get_x86_64_req(struct blkif_request *dst,
+				 struct blkif_x86_64_request *src)
+{
+	int i, n;
+
+	dst->operation = READ_ONCE(src->operation);
+
+	switch (dst->operation) {
+	case BLKIF_OP_READ:
+	case BLKIF_OP_WRITE:
+	case BLKIF_OP_WRITE_BARRIER:
+	case BLKIF_OP_FLUSH_DISKCACHE:
+		dst->u.rw.nr_segments = READ_ONCE(src->u.rw.nr_segments);
+		dst->u.rw.handle = src->u.rw.handle;
+		dst->u.rw.id = src->u.rw.id;
+		dst->u.rw.sector_number = src->u.rw.sector_number;
+		n = min_t(int, BLKIF_MAX_SEGMENTS_PER_REQUEST,
+			  dst->u.rw.nr_segments);
+		for (i = 0; i < n; i++)
+			dst->u.rw.seg[i] = src->u.rw.seg[i];
+		break;
+
+	case BLKIF_OP_DISCARD:
+		dst->u.discard.flag = src->u.discard.flag;
+		dst->u.discard.id = src->u.discard.id;
+		dst->u.discard.sector_number = src->u.discard.sector_number;
+		dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
+		break;
+
+	case BLKIF_OP_INDIRECT:
+		dst->u.indirect.indirect_op = src->u.indirect.indirect_op;
+		dst->u.indirect.nr_segments =
+			READ_ONCE(src->u.indirect.nr_segments);
+		dst->u.indirect.handle = src->u.indirect.handle;
+		dst->u.indirect.id = src->u.indirect.id;
+		dst->u.indirect.sector_number = src->u.indirect.sector_number;
+		n = min(MAX_INDIRECT_PAGES,
+			INDIRECT_PAGES(dst->u.indirect.nr_segments));
+		for (i = 0; i < n; i++)
+			dst->u.indirect.indirect_grefs[i] =
+				src->u.indirect.indirect_grefs[i];
+		break;
+
+	default:
+		/*
+		 * Don't know how to translate this op. Only get the
+		 * ID so failure can be reported to the frontend.
+		 */
+		dst->u.other.id = src->u.other.id;
+		break;
+	}
+}
 
 /*
  * Function to copy the from the ring buffer the 'struct blkif_request'
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index fab8a8dee0da..40f67bfc052d 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -394,100 +394,4 @@  int xen_blkbk_barrier(struct xenbus_transaction xbt,
 struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);
 void xen_blkbk_unmap_purged_grants(struct work_struct *work);
 
-static inline void blkif_get_x86_32_req(struct blkif_request *dst,
-					struct blkif_x86_32_request *src)
-{
-	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j;
-	dst->operation = READ_ONCE(src->operation);
-	switch (dst->operation) {
-	case BLKIF_OP_READ:
-	case BLKIF_OP_WRITE:
-	case BLKIF_OP_WRITE_BARRIER:
-	case BLKIF_OP_FLUSH_DISKCACHE:
-		dst->u.rw.nr_segments = src->u.rw.nr_segments;
-		dst->u.rw.handle = src->u.rw.handle;
-		dst->u.rw.id = src->u.rw.id;
-		dst->u.rw.sector_number = src->u.rw.sector_number;
-		barrier();
-		if (n > dst->u.rw.nr_segments)
-			n = dst->u.rw.nr_segments;
-		for (i = 0; i < n; i++)
-			dst->u.rw.seg[i] = src->u.rw.seg[i];
-		break;
-	case BLKIF_OP_DISCARD:
-		dst->u.discard.flag = src->u.discard.flag;
-		dst->u.discard.id = src->u.discard.id;
-		dst->u.discard.sector_number = src->u.discard.sector_number;
-		dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
-		break;
-	case BLKIF_OP_INDIRECT:
-		dst->u.indirect.indirect_op = src->u.indirect.indirect_op;
-		dst->u.indirect.nr_segments = src->u.indirect.nr_segments;
-		dst->u.indirect.handle = src->u.indirect.handle;
-		dst->u.indirect.id = src->u.indirect.id;
-		dst->u.indirect.sector_number = src->u.indirect.sector_number;
-		barrier();
-		j = min(MAX_INDIRECT_PAGES, INDIRECT_PAGES(dst->u.indirect.nr_segments));
-		for (i = 0; i < j; i++)
-			dst->u.indirect.indirect_grefs[i] =
-				src->u.indirect.indirect_grefs[i];
-		break;
-	default:
-		/*
-		 * Don't know how to translate this op. Only get the
-		 * ID so failure can be reported to the frontend.
-		 */
-		dst->u.other.id = src->u.other.id;
-		break;
-	}
-}
-
-static inline void blkif_get_x86_64_req(struct blkif_request *dst,
-					struct blkif_x86_64_request *src)
-{
-	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j;
-	dst->operation = READ_ONCE(src->operation);
-	switch (dst->operation) {
-	case BLKIF_OP_READ:
-	case BLKIF_OP_WRITE:
-	case BLKIF_OP_WRITE_BARRIER:
-	case BLKIF_OP_FLUSH_DISKCACHE:
-		dst->u.rw.nr_segments = src->u.rw.nr_segments;
-		dst->u.rw.handle = src->u.rw.handle;
-		dst->u.rw.id = src->u.rw.id;
-		dst->u.rw.sector_number = src->u.rw.sector_number;
-		barrier();
-		if (n > dst->u.rw.nr_segments)
-			n = dst->u.rw.nr_segments;
-		for (i = 0; i < n; i++)
-			dst->u.rw.seg[i] = src->u.rw.seg[i];
-		break;
-	case BLKIF_OP_DISCARD:
-		dst->u.discard.flag = src->u.discard.flag;
-		dst->u.discard.id = src->u.discard.id;
-		dst->u.discard.sector_number = src->u.discard.sector_number;
-		dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
-		break;
-	case BLKIF_OP_INDIRECT:
-		dst->u.indirect.indirect_op = src->u.indirect.indirect_op;
-		dst->u.indirect.nr_segments = src->u.indirect.nr_segments;
-		dst->u.indirect.handle = src->u.indirect.handle;
-		dst->u.indirect.id = src->u.indirect.id;
-		dst->u.indirect.sector_number = src->u.indirect.sector_number;
-		barrier();
-		j = min(MAX_INDIRECT_PAGES, INDIRECT_PAGES(dst->u.indirect.nr_segments));
-		for (i = 0; i < j; i++)
-			dst->u.indirect.indirect_grefs[i] =
-				src->u.indirect.indirect_grefs[i];
-		break;
-	default:
-		/*
-		 * Don't know how to translate this op. Only get the
-		 * ID so failure can be reported to the frontend.
-		 */
-		dst->u.other.id = src->u.other.id;
-		break;
-	}
-}
-
 #endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */