4 files changed, 198 insertions, 6 deletions

diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
index acbdcb670ac5..f5b5735f76d5 100644
--- a/drivers/scsi/osd/osd_initiator.c
+++ b/drivers/scsi/osd/osd_initiator.c
@@ -464,6 +464,7 @@ void osd_end_request(struct osd_request *or)
         _osd_free_seg(or, &or->get_attr);
         _osd_free_seg(or, &or->enc_get_attr);
         _osd_free_seg(or, &or->set_attr);
+        _osd_free_seg(or, &or->cdb_cont);
 
         _osd_request_free(or);
 }
@@ -548,6 +549,12 @@ static int _osd_realloc_seg(struct osd_request *or,
         return 0;
 }
 
+static int _alloc_cdb_cont(struct osd_request *or, unsigned total_bytes)
+{
+        OSD_DEBUG("total_bytes=%d\n", total_bytes);
+        return _osd_realloc_seg(or, &or->cdb_cont, total_bytes);
+}
+
 static int _alloc_set_attr_list(struct osd_request *or,
         const struct osd_attr *oa, unsigned nelem, unsigned add_bytes)
 {
@@ -886,6 +893,128 @@ int osd_req_read_kern(struct osd_request *or,
 }
 EXPORT_SYMBOL(osd_req_read_kern);
 
+static int _add_sg_continuation_descriptor(struct osd_request *or,
+        const struct osd_sg_entry *sglist, unsigned numentries, u64 *len)
+{
+        struct osd_sg_continuation_descriptor *oscd;
+        u32 oscd_size;
+        unsigned i;
+        int ret;
+
+        oscd_size = sizeof(*oscd) + numentries * sizeof(oscd->entries[0]);
+
+        if (!or->cdb_cont.total_bytes) {
+                /* First time, jump over the header, we will write to:
+                 *      cdb_cont.buff + cdb_cont.total_bytes
+                 */
+                or->cdb_cont.total_bytes =
+                                sizeof(struct osd_continuation_segment_header);
+        }
+
+        ret = _alloc_cdb_cont(or, or->cdb_cont.total_bytes + oscd_size);
+        if (unlikely(ret))
+                return ret;
+
+        oscd = or->cdb_cont.buff + or->cdb_cont.total_bytes;
+        oscd->hdr.type = cpu_to_be16(SCATTER_GATHER_LIST);
+        oscd->hdr.pad_length = 0;
+        oscd->hdr.length = cpu_to_be32(oscd_size - sizeof(*oscd));
+
+        *len = 0;
+        /* copy the sg entries and convert to network byte order */
+        for (i = 0; i < numentries; i++) {
+                oscd->entries[i].offset = cpu_to_be64(sglist[i].offset);
+                oscd->entries[i].len    = cpu_to_be64(sglist[i].len);
+                *len += sglist[i].len;
+        }
+
+        or->cdb_cont.total_bytes += oscd_size;
+        OSD_DEBUG("total_bytes=%d oscd_size=%d numentries=%d\n",
+                  or->cdb_cont.total_bytes, oscd_size, numentries);
+        return 0;
+}
+
+static int _osd_req_finalize_cdb_cont(struct osd_request *or, const u8 *cap_key)
+{
+        struct request_queue *req_q = osd_request_queue(or->osd_dev);
+        struct bio *bio;
+        struct osd_cdb_head *cdbh = osd_cdb_head(&or->cdb);
+        struct osd_continuation_segment_header *cont_seg_hdr;
+
+        if (!or->cdb_cont.total_bytes)
+                return 0;
+
+        cont_seg_hdr = or->cdb_cont.buff;
+        cont_seg_hdr->format = CDB_CONTINUATION_FORMAT_V2;
+        cont_seg_hdr->service_action = cdbh->varlen_cdb.service_action;
+
+        /* create a bio for continuation segment */
+        bio = bio_map_kern(req_q, or->cdb_cont.buff, or->cdb_cont.total_bytes,
+                           GFP_KERNEL);
+        if (unlikely(!bio))
+                return -ENOMEM;
+
+        bio->bi_rw |= REQ_WRITE;
+
+        /* integrity check the continuation before the bio is linked
+         * with the other data segments since the continuation
+         * integrity is separate from the other data segments.
+         */
+        osd_sec_sign_data(cont_seg_hdr->integrity_check, bio, cap_key);
+
+        cdbh->v2.cdb_continuation_length = cpu_to_be32(or->cdb_cont.total_bytes);
+
+        /* we can't use _req_append_segment, because we need to link in the
+         * continuation bio to the head of the bio list - the
+         * continuation segment (if it exists) is always the first segment in
+         * the out data buffer.
+         */
+        bio->bi_next = or->out.bio;
+        or->out.bio = bio;
+        or->out.total_bytes += or->cdb_cont.total_bytes;
+
+        return 0;
+}
+
+/* osd_req_write_sg: Takes a @bio that points to the data out buffer and an
+ * @sglist that has the scatter gather entries. Scatter-gather enables a write
+ * of multiple none-contiguous areas of an object, in a single call. The extents
+ * may overlap and/or be in any order. The only constrain is that:
+ *      total_bytes(sglist) >= total_bytes(bio)
+ */
+int osd_req_write_sg(struct osd_request *or,
+        const struct osd_obj_id *obj, struct bio *bio,
+        const struct osd_sg_entry *sglist, unsigned numentries)
+{
+        u64 len;
+        int ret = _add_sg_continuation_descriptor(or, sglist, numentries, &len);
+
+        if (ret)
+                return ret;
+        osd_req_write(or, obj, 0, bio, len);
+
+        return 0;
+}
+EXPORT_SYMBOL(osd_req_write_sg);
+
+/* osd_req_read_sg: Read multiple extents of an object into @bio
+ * See osd_req_write_sg
+ */
+int osd_req_read_sg(struct osd_request *or,
+        const struct osd_obj_id *obj, struct bio *bio,
+        const struct osd_sg_entry *sglist, unsigned numentries)
+{
+        u64 len;
+        int ret = _add_sg_continuation_descriptor(or, sglist, numentries, &len);
+
+        if (ret)
+                return ret;
+        osd_req_read(or, obj, 0, bio, len);
+
+        return 0;
+}
+EXPORT_SYMBOL(osd_req_read_sg);
+
 void osd_req_get_attributes(struct osd_request *or,
         const struct osd_obj_id *obj)
 {
@@ -1281,7 +1410,8 @@ static inline void osd_sec_parms_set_in_offset(bool is_v1,
 }
 
 static int _osd_req_finalize_data_integrity(struct osd_request *or,
-        bool has_in, bool has_out, u64 out_data_bytes, const u8 *cap_key)
+        bool has_in, bool has_out, struct bio *out_data_bio, u64 out_data_bytes,
+        const u8 *cap_key)
 {
         struct osd_security_parameters *sec_parms = _osd_req_sec_params(or);
         int ret;
@@ -1312,7 +1442,7 @@ static int _osd_req_finalize_data_integrity(struct osd_request *or,
                 or->out.last_seg = NULL;
 
                 /* they are now all chained to request sign them all together */
-                osd_sec_sign_data(&or->out_data_integ, or->out.req->bio,
+                osd_sec_sign_data(&or->out_data_integ, out_data_bio,
                                   cap_key);
         }
 
@@ -1408,6 +1538,8 @@ int osd_finalize_request(struct osd_request *or,
 {
         struct osd_cdb_head *cdbh = osd_cdb_head(&or->cdb);
         bool has_in, has_out;
+         /* Save for data_integrity without the cdb_continuation */
+        struct bio *out_data_bio = or->out.bio;
         u64 out_data_bytes = or->out.total_bytes;
         int ret;
 
@@ -1423,9 +1555,14 @@ int osd_finalize_request(struct osd_request *or,
         osd_set_caps(&or->cdb, cap);
 
         has_in = or->in.bio || or->get_attr.total_bytes;
-        has_out = or->out.bio || or->set_attr.total_bytes ||
-                or->enc_get_attr.total_bytes;
+        has_out = or->out.bio || or->cdb_cont.total_bytes ||
+                or->set_attr.total_bytes || or->enc_get_attr.total_bytes;
 
+        ret = _osd_req_finalize_cdb_cont(or, cap_key);
+        if (ret) {
+                OSD_DEBUG("_osd_req_finalize_cdb_cont failed\n");
+                return ret;
+        }
         ret = _init_blk_request(or, has_in, has_out);
         if (ret) {
                 OSD_DEBUG("_init_blk_request failed\n");
@@ -1463,7 +1600,8 @@ int osd_finalize_request(struct osd_request *or,
         }
 
         ret = _osd_req_finalize_data_integrity(or, has_in, has_out,
-                                               out_data_bytes, cap_key);
+                                               out_data_bio, out_data_bytes,
+                                               cap_key);
         if (ret)
                 return ret;
 
diff --git a/include/scsi/osd_initiator.h b/include/scsi/osd_initiator.h
index a8f370126632..169a5dcda096 100644
--- a/include/scsi/osd_initiator.h
+++ b/include/scsi/osd_initiator.h
@@ -137,7 +137,7 @@ struct osd_request {
                 void *buff;
                 unsigned alloc_size; /* 0 here means: don't call kfree */
                 unsigned total_bytes;
-        } set_attr, enc_get_attr, get_attr;
+        } cdb_cont, set_attr, enc_get_attr, get_attr;
 
         struct _osd_io_info {
                 struct bio *bio;
@@ -448,6 +448,13 @@ void osd_req_read(struct osd_request *or,
 int osd_req_read_kern(struct osd_request *or,
         const struct osd_obj_id *obj, u64 offset, void *buff, u64 len);
 
+/* Scatter/Gather write/read commands */
+int osd_req_write_sg(struct osd_request *or,
+        const struct osd_obj_id *obj, struct bio *bio,
+        const struct osd_sg_entry *sglist, unsigned numentries);
+int osd_req_read_sg(struct osd_request *or,
+        const struct osd_obj_id *obj, struct bio *bio,
+        const struct osd_sg_entry *sglist, unsigned numentries);
 /*
  * Root/Partition/Collection/Object Attributes commands
  */
diff --git a/include/scsi/osd_protocol.h b/include/scsi/osd_protocol.h
index 685661283540..a6026da25f3e 100644
--- a/include/scsi/osd_protocol.h
+++ b/include/scsi/osd_protocol.h
@@ -631,4 +631,46 @@ static inline void osd_sec_set_caps(struct osd_capability_head *cap,
         put_unaligned_le16(bit_mask, &cap->permissions_bit_mask);
 }
 
+/* osd2r05a sec 5.3: CDB continuation segment formats */
+enum osd_continuation_segment_format {
+        CDB_CONTINUATION_FORMAT_V2 = 0x01,
+};
+
+struct osd_continuation_segment_header {
+        u8      format;
+        u8      reserved1;
+        __be16  service_action;
+        __be32  reserved2;
+        u8      integrity_check[OSDv2_CRYPTO_KEYID_SIZE];
+} __packed;
+
+/* osd2r05a sec 5.4.1: CDB continuation descriptors */
+enum osd_continuation_descriptor_type {
+        NO_MORE_DESCRIPTORS = 0x0000,
+        SCATTER_GATHER_LIST = 0x0001,
+        QUERY_LIST = 0x0002,
+        USER_OBJECT = 0x0003,
+        COPY_USER_OBJECT_SOURCE = 0x0101,
+        EXTENSION_CAPABILITIES = 0xFFEE
+};
+
+struct osd_continuation_descriptor_header {
+        __be16  type;
+        u8      reserved;
+        u8      pad_length;
+        __be32  length;
+} __packed;
+
+
+/* osd2r05a sec 5.4.2: Scatter/gather list */
+struct osd_sg_list_entry {
+        __be64 offset;
+        __be64 len;
+};
+
+struct osd_sg_continuation_descriptor {
+        struct osd_continuation_descriptor_header hdr;
+        struct osd_sg_list_entry entries[];
+};
+
 #endif /* ndef __OSD_PROTOCOL_H__ */
diff --git a/include/scsi/osd_types.h b/include/scsi/osd_types.h
index 3f5e88cc75c0..bd0be7ed4bcf 100644
--- a/include/scsi/osd_types.h
+++ b/include/scsi/osd_types.h
@@ -37,4 +37,9 @@ struct osd_attr {
         void *val_ptr;          /* in network order */
 };
 
+struct osd_sg_entry {
+        u64 offset;
+        u64 len;
+};
+
 #endif /* ndef __OSD_TYPES_H__ */