1 files changed, 81 insertions, 17 deletions

diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index c4bd34063ecc..de09f525d6c1 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -62,13 +62,26 @@ struct blkif_common_response {
 
 /* i386 protocol version */
 #pragma pack(push, 4)
+
+struct blkif_x86_32_request_rw {
+        blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
+        struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+};
+
+struct blkif_x86_32_request_discard {
+        blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
+        uint64_t nr_sectors;
+};
+
 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  */
-        blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
-        struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+        union {
+                struct blkif_x86_32_request_rw rw;
+                struct blkif_x86_32_request_discard discard;
+        } u;
 };
 struct blkif_x86_32_response {
         uint64_t        id;              /* copied from request */
@@ -78,13 +91,26 @@ struct blkif_x86_32_response {
 #pragma pack(pop)
 
 /* x86_64 protocol version */
+
+struct blkif_x86_64_request_rw {
+        blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
+        struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+};
+
+struct blkif_x86_64_request_discard {
+        blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
+        uint64_t nr_sectors;
+};
+
 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;
-        blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
-        struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+        union {
+                struct blkif_x86_64_request_rw rw;
+                struct blkif_x86_64_request_discard discard;
+        } u;
 };
 struct blkif_x86_64_response {
         uint64_t       __attribute__((__aligned__(8))) id;
@@ -112,6 +138,11 @@ enum blkif_protocol {
         BLKIF_PROTOCOL_X86_64 = 3,
 };
 
+enum blkif_backend_type {
+        BLKIF_BACKEND_PHY  = 1,
+        BLKIF_BACKEND_FILE = 2,
+};
+
 struct xen_vbd {
         /* What the domain refers to this vbd as. */
         blkif_vdev_t            handle;
@@ -137,6 +168,7 @@ struct xen_blkif {
         unsigned int            irq;
         /* Comms information. */
         enum blkif_protocol     blk_protocol;
+        enum blkif_backend_type blk_backend_type;
         union blkif_back_rings  blk_rings;
         struct vm_struct        *blk_ring_area;
         /* The VBD attached to this interface. */
@@ -148,6 +180,9 @@ struct xen_blkif {
         atomic_t                refcnt;
 
         wait_queue_head_t       wq;
+        /* for barrier (drain) requests */
+        struct completion       drain_complete;
+        atomic_t                drain;
         /* One thread per one blkif. */
         struct task_struct      *xenblkd;
         unsigned int            waiting_reqs;
@@ -158,6 +193,7 @@ struct xen_blkif {
         int                     st_wr_req;
         int                     st_oo_req;
         int                     st_f_req;
+        int                     st_ds_req;
         int                     st_rd_sect;
         int                     st_wr_sect;
 
@@ -181,7 +217,7 @@ struct xen_blkif {
 
 struct phys_req {
         unsigned short          dev;
-        unsigned short          nr_sects;
+        blkif_sector_t          nr_sects;
         struct block_device     *bdev;
         blkif_sector_t          sector_number;
 };
@@ -195,6 +231,8 @@ int xen_blkif_schedule(void *arg);
 int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
                               struct backend_info *be, int state);
 
+int xen_blkbk_barrier(struct xenbus_transaction xbt,
+                      struct backend_info *be, int state);
 struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);
 
 static inline void blkif_get_x86_32_req(struct blkif_request *dst,
@@ -205,12 +243,25 @@ static inline void blkif_get_x86_32_req(struct blkif_request *dst,
         dst->nr_segments = src->nr_segments;
         dst->handle = src->handle;
         dst->id = src->id;
-        dst->u.rw.sector_number = src->sector_number;
-        barrier();
-        if (n > dst->nr_segments)
-                n = dst->nr_segments;
-        for (i = 0; i < n; i++)
-                dst->u.rw.seg[i] = src->seg[i];
+        switch (src->operation) {
+        case BLKIF_OP_READ:
+        case BLKIF_OP_WRITE:
+        case BLKIF_OP_WRITE_BARRIER:
+        case BLKIF_OP_FLUSH_DISKCACHE:
+                dst->u.rw.sector_number = src->u.rw.sector_number;
+                barrier();
+                if (n > dst->nr_segments)
+                        n = dst->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.sector_number = src->u.discard.sector_number;
+                dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
+                break;
+        default:
+                break;
+        }
 }
 
 static inline void blkif_get_x86_64_req(struct blkif_request *dst,
@@ -221,12 +272,25 @@ static inline void blkif_get_x86_64_req(struct blkif_request *dst,
         dst->nr_segments = src->nr_segments;
         dst->handle = src->handle;
         dst->id = src->id;
-        dst->u.rw.sector_number = src->sector_number;
-        barrier();
-        if (n > dst->nr_segments)
-                n = dst->nr_segments;
-        for (i = 0; i < n; i++)
-                dst->u.rw.seg[i] = src->seg[i];
+        switch (src->operation) {
+        case BLKIF_OP_READ:
+        case BLKIF_OP_WRITE:
+        case BLKIF_OP_WRITE_BARRIER:
+        case BLKIF_OP_FLUSH_DISKCACHE:
+                dst->u.rw.sector_number = src->u.rw.sector_number;
+                barrier();
+                if (n > dst->nr_segments)
+                        n = dst->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.sector_number = src->u.discard.sector_number;
+                dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
+                break;
+        default:
+                break;
+        }
 }
 
 #endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */