[SCSI] libosd: OSD2r05: Prepare for rev5 attribute list changes

In OSD2r05 draft each attribute list element header was changed
so attribute-value would be 8 bytes aligned. In OSD2r01-r04
it was aligned on 2 bytes. (This is because in OSD2r01 the complete
element was 8 bytes padded at end but the header was not adjusted
and caused permanent miss-alignment.)

OSD1 elements are not padded and might be or might not be aligned.
OSD1 is still supported.

In this code we do all the code re-factoring to separate OSD1/OSD2
differences but do not change actual wire format. All wire format
changes will happen in one patch later, for bisect-ability.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
index 76de88962237953c4c9e59e55065c88edfd0820f..e266f803aa96815e6097f4d2ba343fe6ccd494e2 100644 (file)
--- a/drivers/scsi/osd/osd_initiator.c
+++ b/drivers/scsi/osd/osd_initiator.c
@@ -205,6 +205,69 @@ static unsigned _osd_req_alist_elem_size(struct osd_request *or, unsigned len)
                osdv2_attr_list_elem_size(len);
 }
 
+static void _osd_req_alist_elem_encode(struct osd_request *or,
+       void *attr_last, const struct osd_attr *oa)
+{
+       if (osd_req_is_ver1(or)) {
+               struct osdv1_attributes_list_element *attr = attr_last;
+
+               attr->attr_page = cpu_to_be32(oa->attr_page);
+               attr->attr_id = cpu_to_be32(oa->attr_id);
+               attr->attr_bytes = cpu_to_be16(oa->len);
+               memcpy(attr->attr_val, oa->val_ptr, oa->len);
+       } else {
+               struct osdv2_attributes_list_element *attr = attr_last;
+
+               attr->attr_page = cpu_to_be32(oa->attr_page);
+               attr->attr_id = cpu_to_be32(oa->attr_id);
+               attr->attr_bytes = cpu_to_be16(oa->len);
+               memcpy(attr->attr_val, oa->val_ptr, oa->len);
+       }
+}
+
+static int _osd_req_alist_elem_decode(struct osd_request *or,
+       void *cur_p, struct osd_attr *oa, unsigned max_bytes)
+{
+       unsigned inc;
+       if (osd_req_is_ver1(or)) {
+               struct osdv1_attributes_list_element *attr = cur_p;
+
+               if (max_bytes < sizeof(*attr))
+                       return -1;
+
+               oa->len = be16_to_cpu(attr->attr_bytes);
+               inc = _osd_req_alist_elem_size(or, oa->len);
+               if (inc > max_bytes)
+                       return -1;
+
+               oa->attr_page = be32_to_cpu(attr->attr_page);
+               oa->attr_id = be32_to_cpu(attr->attr_id);
+
+               /* OSD1: On empty attributes we return a pointer to 2 bytes
+                * of zeros. This keeps similar behaviour with OSD2.
+                * (See below)
+                */
+               oa->val_ptr = likely(oa->len) ? attr->attr_val :
+                                               (u8 *)&attr->attr_bytes;
+       } else {
+               struct osdv2_attributes_list_element *attr = cur_p;
+
+               if (max_bytes < sizeof(*attr))
+                       return -1;
+
+               oa->len = be16_to_cpu(attr->attr_bytes);
+               inc = _osd_req_alist_elem_size(or, oa->len);
+               if (inc > max_bytes)
+                       return -1;
+
+               oa->attr_page = be32_to_cpu(attr->attr_page);
+               oa->attr_id = be32_to_cpu(attr->attr_id);
+
+               oa->val_ptr = attr->attr_val;
+       }
+       return inc;
+}
+
 static unsigned _osd_req_alist_size(struct osd_request *or, void *list_head)
 {
        return osd_req_is_ver1(or) ?
@@ -798,7 +861,6 @@ int osd_req_add_set_attr_list(struct osd_request *or,
        attr_last = or->set_attr.buff + total_bytes;
 
        for (; nelem; --nelem) {
-               struct osd_attributes_list_element *attr;
                unsigned elem_size = _osd_req_alist_elem_size(or, oa->len);
 
                total_bytes += elem_size;
@@ -811,11 +873,7 @@ int osd_req_add_set_attr_list(struct osd_request *or,
                                or->set_attr.buff + or->set_attr.total_bytes;
                }
 
-               attr = attr_last;
-               attr->attr_page = cpu_to_be32(oa->attr_page);
-               attr->attr_id = cpu_to_be32(oa->attr_id);
-               attr->attr_bytes = cpu_to_be16(oa->len);
-               memcpy(attr->attr_val, oa->val_ptr, oa->len);
+               _osd_req_alist_elem_encode(or, attr_last, oa);
 
                attr_last += elem_size;
                ++oa;
@@ -1070,15 +1128,10 @@ int osd_req_decode_get_attr_list(struct osd_request *or,
        }
 
        for (n = 0; (n < *nelem) && (cur_bytes < returned_bytes); ++n) {
-               struct osd_attributes_list_element *attr = cur_p;
-               unsigned inc;
+               int inc = _osd_req_alist_elem_decode(or, cur_p, oa,
+                                                returned_bytes - cur_bytes);
 
-               oa->len = be16_to_cpu(attr->attr_bytes);
-               inc = _osd_req_alist_elem_size(or, oa->len);
-               OSD_DEBUG("oa->len=%d inc=%d cur_bytes=%d\n",
-                         oa->len, inc, cur_bytes);
-               cur_bytes += inc;
-               if (cur_bytes > returned_bytes) {
+               if (inc < 0) {
                        OSD_ERR("BAD FOOD from target. list not valid!"
                                "c=%d r=%d n=%d\n",
                                cur_bytes, returned_bytes, n);
@@ -1086,10 +1139,7 @@ int osd_req_decode_get_attr_list(struct osd_request *or,
                        break;
                }
 
-               oa->attr_page = be32_to_cpu(attr->attr_page);
-               oa->attr_id = be32_to_cpu(attr->attr_id);
-               oa->val_ptr = attr->attr_val;
-
+               cur_bytes += inc;
                cur_p += inc;
                ++oa;
        }

diff --git a/include/scsi/osd_protocol.h b/include/scsi/osd_protocol.h
index cd3cbf764650840b623ac22b0ec708f219e093da..fa8343ce3ca277ba536142f638052eaaf52be3a9 100644 (file)
--- a/include/scsi/osd_protocol.h
+++ b/include/scsi/osd_protocol.h
@@ -300,15 +300,25 @@ struct osd_attributes_list_attrid {
        __be32 attr_id;
 } __packed;
 
+/*
+ * NOTE: v1: is not aligned.
+ */
+struct osdv1_attributes_list_element {
+       __be32 attr_page;
+       __be32 attr_id;
+       __be16 attr_bytes; /* valid bytes at attr_val without padding */
+       u8 attr_val[0];
+} __packed;
+
 /*
  * osd2r03: 7.1.3.3 List entry format for retrieved attributes and
  *                  for setting attributes
- * NOTE: v2 is 8-bytes aligned, v1 is not aligned.
+ * NOTE: v2 is 8-bytes aligned
  */
-struct osd_attributes_list_element {
+struct osdv2_attributes_list_element {
        __be32 attr_page;
        __be32 attr_id;
-       __be16 attr_bytes;
+       __be16 attr_bytes; /* valid bytes at attr_val without padding */
        u8 attr_val[0];
 } __packed;
 
@@ -324,13 +334,13 @@ enum {
 
 static inline unsigned osdv1_attr_list_elem_size(unsigned len)
 {
-       return ALIGN(len + sizeof(struct osd_attributes_list_element),
+       return ALIGN(len + sizeof(struct osdv1_attributes_list_element),
                     OSDv1_ATTRIBUTES_ELEM_ALIGN);
 }
 
 static inline unsigned osdv2_attr_list_elem_size(unsigned len)
 {
-       return ALIGN(len + sizeof(struct osd_attributes_list_element),
+       return ALIGN(len + sizeof(struct osdv2_attributes_list_element),
                     OSD_ATTRIBUTES_ELEM_ALIGN);
 }