xen-blkif: drop struct blkif_request_segment_aligned
This was wrongly introduced in commit 402b27f9, the only difference
between blkif_request_segment_aligned and blkif_request_segment is
that the former has a named padding, while both share the same
memory layout.
Also correct a few minor glitches in the description, including for it
to no longer assume PAGE_SIZE == 4096.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
[Description fix by Jan Beulich]
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reported-by: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Matt Rushton <mrushton@amazon.com>
Cc: Matt Wilson <msw@amazon.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 394fa2e..e612627 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -847,7 +847,7 @@
struct grant_page **pages = pending_req->indirect_pages;
struct xen_blkif *blkif = pending_req->blkif;
int indirect_grefs, rc, n, nseg, i;
- struct blkif_request_segment_aligned *segments = NULL;
+ struct blkif_request_segment *segments = NULL;
nseg = pending_req->nr_pages;
indirect_grefs = INDIRECT_PAGES(nseg);
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index e40326a..9eb34e2 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -57,7 +57,7 @@
#define MAX_INDIRECT_SEGMENTS 256
#define SEGS_PER_INDIRECT_FRAME \
- (PAGE_SIZE/sizeof(struct blkif_request_segment_aligned))
+ (PAGE_SIZE/sizeof(struct blkif_request_segment))
#define MAX_INDIRECT_PAGES \
((MAX_INDIRECT_SEGMENTS + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
#define INDIRECT_PAGES(_segs) \
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index c4a4c90..7d09dfc 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -162,7 +162,7 @@
#define DEV_NAME "xvd" /* name in /dev */
#define SEGS_PER_INDIRECT_FRAME \
- (PAGE_SIZE/sizeof(struct blkif_request_segment_aligned))
+ (PAGE_SIZE/sizeof(struct blkif_request_segment))
#define INDIRECT_GREFS(_segs) \
((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
@@ -393,7 +393,7 @@
unsigned long id;
unsigned int fsect, lsect;
int i, ref, n;
- struct blkif_request_segment_aligned *segments = NULL;
+ struct blkif_request_segment *segments = NULL;
/*
* Used to store if we are able to queue the request by just using
@@ -550,7 +550,7 @@
} else {
n = i % SEGS_PER_INDIRECT_FRAME;
segments[n] =
- (struct blkif_request_segment_aligned) {
+ (struct blkif_request_segment) {
.gref = ref,
.first_sect = fsect,
.last_sect = lsect };
diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h
index ae665ac..32ec05a 100644
--- a/include/xen/interface/io/blkif.h
+++ b/include/xen/interface/io/blkif.h
@@ -113,13 +113,13 @@
* it's less than the number provided by the backend. The indirect_grefs field
* in blkif_request_indirect should be filled by the frontend with the
* grant references of the pages that are holding the indirect segments.
- * This pages are filled with an array of blkif_request_segment_aligned
- * that hold the information about the segments. The number of indirect
- * pages to use is determined by the maximum number of segments
- * a indirect request contains. Every indirect page can contain a maximum
- * of 512 segments (PAGE_SIZE/sizeof(blkif_request_segment_aligned)),
- * so to calculate the number of indirect pages to use we have to do
- * ceil(indirect_segments/512).
+ * These pages are filled with an array of blkif_request_segment that hold the
+ * information about the segments. The number of indirect pages to use is
+ * determined by the number of segments an indirect request contains. Every
+ * indirect page can contain a maximum of
+ * (PAGE_SIZE / sizeof(struct blkif_request_segment)) segments, so to
+ * calculate the number of indirect pages to use we have to do
+ * ceil(indirect_segments / (PAGE_SIZE / sizeof(struct blkif_request_segment))).
*
* If a backend does not recognize BLKIF_OP_INDIRECT, it should *not*
* create the "feature-max-indirect-segments" node!
@@ -135,13 +135,12 @@
#define BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST 8
-struct blkif_request_segment_aligned {
- grant_ref_t gref; /* reference to I/O buffer frame */
- /* @first_sect: first sector in frame to transfer (inclusive). */
- /* @last_sect: last sector in frame to transfer (inclusive). */
- uint8_t first_sect, last_sect;
- uint16_t _pad; /* padding to make it 8 bytes, so it's cache-aligned */
-} __attribute__((__packed__));
+struct blkif_request_segment {
+ grant_ref_t gref; /* reference to I/O buffer frame */
+ /* @first_sect: first sector in frame to transfer (inclusive). */
+ /* @last_sect: last sector in frame to transfer (inclusive). */
+ uint8_t first_sect, last_sect;
+};
struct blkif_request_rw {
uint8_t nr_segments; /* number of segments */
@@ -151,12 +150,7 @@
#endif
uint64_t id; /* private guest value, echoed in resp */
blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
- struct blkif_request_segment {
- grant_ref_t gref; /* reference to I/O buffer frame */
- /* @first_sect: first sector in frame to transfer (inclusive). */
- /* @last_sect: last sector in frame to transfer (inclusive). */
- uint8_t first_sect, last_sect;
- } seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+ struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
} __attribute__((__packed__));
struct blkif_request_discard {
