diff options
author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-10-12 16:12:36 (GMT) |
---|---|---|
committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-11-18 18:27:59 (GMT) |
commit | 97e36834f5a106459ab1b290e663a4eb6264639e (patch) | |
tree | 39e4843998cb7f75b94d80f27e4b11ffb3662f28 /drivers/block/xen-blkback | |
parent | cfcfc9eca2bcbd26a8e206baeb005b055dbf8e37 (diff) | |
download | linux-fsl-qoriq-97e36834f5a106459ab1b290e663a4eb6264639e.tar.xz |
xen/blk[front|back]: Squash blkif_request_rw and blkif_request_discard together
In a union type structure to deal with the overlapping
attributes in a easier manner.
Suggested-by: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/block/xen-blkback')
-rw-r--r-- | drivers/block/xen-blkback/blkback.c | 13 | ||||
-rw-r--r-- | drivers/block/xen-blkback/common.h | 64 |
2 files changed, 43 insertions, 34 deletions
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 15ec4db..d7104ab 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -362,7 +362,7 @@ static int xen_blkbk_map(struct blkif_request *req, { struct gnttab_map_grant_ref map[BLKIF_MAX_SEGMENTS_PER_REQUEST]; int i; - int nseg = req->nr_segments; + int nseg = req->u.rw.nr_segments; int ret = 0; /* @@ -449,7 +449,7 @@ static void xen_blk_discard(struct xen_blkif *blkif, struct blkif_request *req) } else if (err) status = BLKIF_RSP_ERROR; - make_response(blkif, req->id, req->operation, status); + make_response(blkif, req->u.discard.id, req->operation, status); } static void xen_blk_drain_io(struct xen_blkif *blkif) @@ -644,7 +644,8 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, } /* Check that the number of segments is sane. */ - nseg = req->nr_segments; + nseg = req->u.rw.nr_segments; + if (unlikely(nseg == 0 && operation != WRITE_FLUSH && operation != REQ_DISCARD) || unlikely(nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST)) { @@ -654,12 +655,12 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, goto fail_response; } - preq.dev = req->handle; + preq.dev = req->u.rw.handle; preq.sector_number = req->u.rw.sector_number; preq.nr_sects = 0; pending_req->blkif = blkif; - pending_req->id = req->id; + pending_req->id = req->u.rw.id; pending_req->operation = req->operation; pending_req->status = BLKIF_RSP_OKAY; pending_req->nr_pages = nseg; @@ -784,7 +785,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, xen_blkbk_unmap(pending_req); fail_response: /* Haven't submitted any bio's yet. */ - make_response(blkif, req->id, req->operation, BLKIF_RSP_ERROR); + make_response(blkif, req->u.rw.id, req->operation, BLKIF_RSP_ERROR); free_req(pending_req); msleep(1); /* back off a bit */ return -EIO; diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index dfb1b3a..dbfe7b3 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -60,58 +60,66 @@ struct blkif_common_response { char dummy; }; -/* i386 protocol version */ -#pragma pack(push, 4) - struct blkif_x86_32_request_rw { + uint8_t nr_segments; /* number of segments */ + blkif_vdev_t handle; /* only for read/write requests */ + 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 seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; -}; +} __attribute__((__packed__)); struct blkif_x86_32_request_discard { + uint8_t nr_segments; /* number of segments */ + blkif_vdev_t _pad1; /* was "handle" for read/write requests */ + uint64_t id; /* private guest value, echoed in resp */ blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ - uint64_t nr_sectors; -}; + uint64_t nr_sectors; +} __attribute__((__packed__)); struct blkif_x86_32_request { uint8_t operation; /* BLKIF_OP_??? */ - uint8_t nr_segments; /* number of segments */ - blkif_vdev_t handle; /* only for read/write requests */ - uint64_t id; /* private guest value, echoed in resp */ union { struct blkif_x86_32_request_rw rw; struct blkif_x86_32_request_discard discard; } u; -}; +} __attribute__((__packed__)); + +/* i386 protocol version */ +#pragma pack(push, 4) struct blkif_x86_32_response { uint64_t id; /* copied from request */ uint8_t operation; /* copied from request */ int16_t status; /* BLKIF_RSP_??? */ }; #pragma pack(pop) - /* x86_64 protocol version */ struct blkif_x86_64_request_rw { + uint8_t nr_segments; /* number of segments */ + blkif_vdev_t handle; /* only for read/write requests */ + uint32_t _pad1; /* offsetof(blkif_reqest..,u.rw.id)==8 */ + uint64_t id; blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; -}; +} __attribute__((__packed__)); struct blkif_x86_64_request_discard { + uint8_t nr_segments; /* number of segments */ + blkif_vdev_t _pad1; /* was "handle" for read/write requests */ + uint32_t _pad2; /* offsetof(blkif_..,u.discard.id)==8 */ + uint64_t id; blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ - uint64_t nr_sectors; -}; + uint64_t nr_sectors; +} __attribute__((__packed__)); struct blkif_x86_64_request { uint8_t operation; /* BLKIF_OP_??? */ - uint8_t nr_segments; /* number of segments */ - blkif_vdev_t handle; /* only for read/write requests */ - uint64_t __attribute__((__aligned__(8))) id; union { struct blkif_x86_64_request_rw rw; struct blkif_x86_64_request_discard discard; } u; -}; +} __attribute__((__packed__)); + struct blkif_x86_64_response { uint64_t __attribute__((__aligned__(8))) id; uint8_t operation; /* copied from request */ @@ -237,18 +245,18 @@ static inline void blkif_get_x86_32_req(struct blkif_request *dst, { int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST; dst->operation = src->operation; - dst->nr_segments = src->nr_segments; - dst->handle = src->handle; - dst->id = src->id; switch (src->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->nr_segments) - n = dst->nr_segments; + 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; @@ -266,18 +274,18 @@ static inline void blkif_get_x86_64_req(struct blkif_request *dst, { int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST; dst->operation = src->operation; - dst->nr_segments = src->nr_segments; - dst->handle = src->handle; - dst->id = src->id; switch (src->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->nr_segments) - n = dst->nr_segments; + 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; |