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>
This commit is contained in:
parent
c05f3e3c85
commit
80bfa2f6e2
4 changed files with 19 additions and 25 deletions
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@ -847,7 +847,7 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req,
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struct grant_page **pages = pending_req->indirect_pages;
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struct xen_blkif *blkif = pending_req->blkif;
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int indirect_grefs, rc, n, nseg, i;
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struct blkif_request_segment_aligned *segments = NULL;
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struct blkif_request_segment *segments = NULL;
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nseg = pending_req->nr_pages;
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indirect_grefs = INDIRECT_PAGES(nseg);
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@ -57,7 +57,7 @@
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#define MAX_INDIRECT_SEGMENTS 256
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#define SEGS_PER_INDIRECT_FRAME \
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(PAGE_SIZE/sizeof(struct blkif_request_segment_aligned))
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(PAGE_SIZE/sizeof(struct blkif_request_segment))
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#define MAX_INDIRECT_PAGES \
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((MAX_INDIRECT_SEGMENTS + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
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#define INDIRECT_PAGES(_segs) \
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@ -162,7 +162,7 @@ static DEFINE_SPINLOCK(minor_lock);
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#define DEV_NAME "xvd" /* name in /dev */
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#define SEGS_PER_INDIRECT_FRAME \
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(PAGE_SIZE/sizeof(struct blkif_request_segment_aligned))
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(PAGE_SIZE/sizeof(struct blkif_request_segment))
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#define INDIRECT_GREFS(_segs) \
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((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
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@ -393,7 +393,7 @@ static int blkif_queue_request(struct request *req)
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unsigned long id;
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unsigned int fsect, lsect;
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int i, ref, n;
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struct blkif_request_segment_aligned *segments = NULL;
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struct blkif_request_segment *segments = NULL;
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/*
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* Used to store if we are able to queue the request by just using
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@ -550,7 +550,7 @@ static int blkif_queue_request(struct request *req)
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} else {
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n = i % SEGS_PER_INDIRECT_FRAME;
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segments[n] =
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(struct blkif_request_segment_aligned) {
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(struct blkif_request_segment) {
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.gref = ref,
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.first_sect = fsect,
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.last_sect = lsect };
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@ -113,13 +113,13 @@ typedef uint64_t blkif_sector_t;
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* it's less than the number provided by the backend. The indirect_grefs field
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* in blkif_request_indirect should be filled by the frontend with the
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* grant references of the pages that are holding the indirect segments.
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* This pages are filled with an array of blkif_request_segment_aligned
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* that hold the information about the segments. The number of indirect
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* pages to use is determined by the maximum number of segments
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* a indirect request contains. Every indirect page can contain a maximum
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* of 512 segments (PAGE_SIZE/sizeof(blkif_request_segment_aligned)),
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* so to calculate the number of indirect pages to use we have to do
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* ceil(indirect_segments/512).
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* These pages are filled with an array of blkif_request_segment that hold the
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* information about the segments. The number of indirect pages to use is
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* determined by the number of segments an indirect request contains. Every
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* indirect page can contain a maximum of
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* (PAGE_SIZE / sizeof(struct blkif_request_segment)) segments, so to
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* calculate the number of indirect pages to use we have to do
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* ceil(indirect_segments / (PAGE_SIZE / sizeof(struct blkif_request_segment))).
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*
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* If a backend does not recognize BLKIF_OP_INDIRECT, it should *not*
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* create the "feature-max-indirect-segments" node!
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@ -135,13 +135,12 @@ typedef uint64_t blkif_sector_t;
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#define BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST 8
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struct blkif_request_segment_aligned {
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grant_ref_t gref; /* reference to I/O buffer frame */
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/* @first_sect: first sector in frame to transfer (inclusive). */
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/* @last_sect: last sector in frame to transfer (inclusive). */
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uint8_t first_sect, last_sect;
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uint16_t _pad; /* padding to make it 8 bytes, so it's cache-aligned */
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} __attribute__((__packed__));
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struct blkif_request_segment {
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grant_ref_t gref; /* reference to I/O buffer frame */
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/* @first_sect: first sector in frame to transfer (inclusive). */
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/* @last_sect: last sector in frame to transfer (inclusive). */
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uint8_t first_sect, last_sect;
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};
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struct blkif_request_rw {
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uint8_t nr_segments; /* number of segments */
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@ -151,12 +150,7 @@ struct blkif_request_rw {
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#endif
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uint64_t id; /* private guest value, echoed in resp */
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blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
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struct blkif_request_segment {
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grant_ref_t gref; /* reference to I/O buffer frame */
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/* @first_sect: first sector in frame to transfer (inclusive). */
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/* @last_sect: last sector in frame to transfer (inclusive). */
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uint8_t first_sect, last_sect;
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} seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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} __attribute__((__packed__));
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struct blkif_request_discard {
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