Full buffers must always be processed, otherwise bad things could happen

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@3400 d57e44dd-8a1f-0410-8b47-8ef2f437770f

scst/include/scst.h

@@ -3524,6 +3524,10 @@ void scst_copy_sg(struct scst_cmd *cmd, enum scst_sg_copy_dir copy_dir);
  * instead of direct access. Returns the buffer length for success, 0 for EOD,
  * negative error code otherwise.
  *
+ * Never EVER use this function to process only "the first page" of the buffer.
+ * The first SG entry can be as low as few bytes long. Use scst_get_full_buf()
+ * instead for such cases.
+ *
  * "Buf" argument returns the mapped buffer
  *
  * The "put" function unmaps the buffer.

scst/src/dev_handlers/scst_vdisk.c

@@ -1393,11 +1393,11 @@ static void vdisk_exec_inquiry(struct scst_cmd *cmd)
 		goto out;
 	}
 
-	length = scst_get_buf_first(cmd, &address);
+	length = scst_get_full_buf(cmd, &address);
 	TRACE_DBG("length %d", length);
 	if (unlikely(length <= 0)) {
 		if (length < 0) {
-			PRINT_ERROR("scst_get_buf_first() failed: %d", length);
+			PRINT_ERROR("scst_get_full_buf() failed: %d", length);
 			scst_set_cmd_error(cmd,
 				SCST_LOAD_SENSE(scst_sense_hardw_error));
 		}
@@ -1674,7 +1674,7 @@ static void vdisk_exec_inquiry(struct scst_cmd *cmd)
 	memcpy(address, buf, length);
 
 out_put:
-	scst_put_buf(cmd, address);
+	scst_put_full_buf(cmd, address);
 	if (length < cmd->resp_data_len)
 		scst_set_resp_data_len(cmd, length);
 
@@ -1697,10 +1697,10 @@ static void vdisk_exec_request_sense(struct scst_cmd *cmd)
 	sl = scst_set_sense(b, sizeof(b), cmd->dev->d_sense,
 		SCST_LOAD_SENSE(scst_sense_no_sense));
 
-	length = scst_get_buf_first(cmd, &address);
+	length = scst_get_full_buf(cmd, &address);
 	TRACE_DBG("length %d", length);
 	if (length < 0) {
-		PRINT_ERROR("scst_get_buf_first() failed: %d)", length);
+		PRINT_ERROR("scst_get_full_buf() failed: %d)", length);
 		scst_set_cmd_error(cmd,
 			SCST_LOAD_SENSE(scst_sense_hardw_error));
 		goto out;
@@ -1710,7 +1710,7 @@ static void vdisk_exec_request_sense(struct scst_cmd *cmd)
 	memcpy(address, b, length);
 	scst_set_resp_data_len(cmd, length);
 
-	scst_put_buf(cmd, address);
+	scst_put_full_buf(cmd, address);
 
 out:
 	TRACE_EXIT();
@@ -1896,10 +1896,10 @@ static void vdisk_exec_mode_sense(struct scst_cmd *cmd)
 	if (!virt_dev->blockio)
 		dev_spec |= DPOFUA;
 
-	length = scst_get_buf_first(cmd, &address);
+	length = scst_get_full_buf(cmd, &address);
 	if (unlikely(length <= 0)) {
 		if (length < 0) {
-			PRINT_ERROR("scst_get_buf_first() failed: %d", length);
+			PRINT_ERROR("scst_get_full_buf() failed: %d", length);
 			scst_set_cmd_error(cmd,
 				SCST_LOAD_SENSE(scst_sense_hardw_error));
 		}
@@ -2008,7 +2008,7 @@ static void vdisk_exec_mode_sense(struct scst_cmd *cmd)
 	memcpy(address, buf, offset);
 
 out_put:
-	scst_put_buf(cmd, address);
+	scst_put_full_buf(cmd, address);
 	if (offset < cmd->resp_data_len)
 		scst_set_resp_data_len(cmd, offset);
 
@@ -2081,10 +2081,10 @@ static void vdisk_exec_mode_select(struct scst_cmd *cmd)
 	virt_dev = cmd->dev->dh_priv;
 	mselect_6 = (MODE_SELECT == cmd->cdb[0]);
 
-	length = scst_get_buf_first(cmd, &address);
+	length = scst_get_full_buf(cmd, &address);
 	if (unlikely(length <= 0)) {
 		if (length < 0) {
-			PRINT_ERROR("scst_get_buf_first() failed: %d", length);
+			PRINT_ERROR("scst_get_full_buf() failed: %d", length);
 			scst_set_cmd_error(cmd,
 				SCST_LOAD_SENSE(scst_sense_hardw_error));
 		}
@@ -2159,7 +2159,7 @@ static void vdisk_exec_mode_select(struct scst_cmd *cmd)
 	}
 
 out_put:
-	scst_put_buf(cmd, address);
+	scst_put_full_buf(cmd, address);
 
 out:
 	TRACE_EXIT();
@@ -2227,10 +2227,10 @@ static void vdisk_exec_read_capacity(struct scst_cmd *cmd)
 	buffer[6] = (blocksize >> (BYTE * 1)) & 0xFF;
 	buffer[7] = (blocksize >> (BYTE * 0)) & 0xFF;
 
-	length = scst_get_buf_first(cmd, &address);
+	length = scst_get_full_buf(cmd, &address);
 	if (unlikely(length <= 0)) {
 		if (length < 0) {
-			PRINT_ERROR("scst_get_buf_first() failed: %d", length);
+			PRINT_ERROR("scst_get_full_buf() failed: %d", length);
 			scst_set_cmd_error(cmd,
 				SCST_LOAD_SENSE(scst_sense_hardw_error));
 		}
@@ -2241,7 +2241,7 @@ static void vdisk_exec_read_capacity(struct scst_cmd *cmd)
 
 	memcpy(address, buffer, length);
 
-	scst_put_buf(cmd, address);
+	scst_put_full_buf(cmd, address);
 
 	if (length < cmd->resp_data_len)
 		scst_set_resp_data_len(cmd, length);
@@ -2320,10 +2320,10 @@ static void vdisk_exec_read_capacity16(struct scst_cmd *cmd)
 #endif
 	}
 
-	length = scst_get_buf_first(cmd, &address);
+	length = scst_get_full_buf(cmd, &address);
 	if (unlikely(length <= 0)) {
 		if (length < 0) {
-			PRINT_ERROR("scst_get_buf_first() failed: %d", length);
+			PRINT_ERROR("scst_get_full_buf() failed: %d", length);
 			scst_set_cmd_error(cmd,
 				SCST_LOAD_SENSE(scst_sense_hardw_error));
 			}
@@ -2334,7 +2334,7 @@ static void vdisk_exec_read_capacity16(struct scst_cmd *cmd)
 
 	memcpy(address, buffer, length);
 
-	scst_put_buf(cmd, address);
+	scst_put_full_buf(cmd, address);
 
 	if (length < cmd->resp_data_len)
 		scst_set_resp_data_len(cmd, length);
@@ -2378,10 +2378,10 @@ static void vdisk_exec_read_toc(struct scst_cmd *cmd)
 		goto out;
 	}
 
-	length = scst_get_buf_first(cmd, &address);
+	length = scst_get_full_buf(cmd, &address);
 	if (unlikely(length <= 0)) {
 		if (length < 0) {
-			PRINT_ERROR("scst_get_buf_first() failed: %d", length);
+			PRINT_ERROR("scst_get_full_buf() failed: %d", length);
 			scst_set_cmd_error(cmd,
 				SCST_LOAD_SENSE(scst_sense_hardw_error));
 		}
@@ -2425,7 +2425,7 @@ static void vdisk_exec_read_toc(struct scst_cmd *cmd)
 		off = length;
 	memcpy(address, buffer, off);
 
-	scst_put_buf(cmd, address);
+	scst_put_full_buf(cmd, address);
 
 	if (off < cmd->resp_data_len)
 		scst_set_resp_data_len(cmd, off);

scst/src/scst_lib.c

@@ -2122,6 +2122,8 @@ void scst_set_resp_data_len(struct scst_cmd *cmd, int resp_data_len)
 	if (resp_data_len == cmd->bufflen)
 		goto out;
 
+	TRACE_DBG("cmd %p, resp_data_len %d", cmd, resp_data_len);
+
 	scst_adjust_sg(cmd, cmd->sg, &cmd->sg_cnt, resp_data_len);
 
 	cmd->resid_possible = 1;
@@ -3798,7 +3800,7 @@ static void scst_complete_request_sense(struct scst_cmd *req_cmd)
 
 	sBUG_ON(orig_cmd == NULL);
 
-	len = scst_get_buf_first(req_cmd, &buf);
+	len = scst_get_full_buf(req_cmd, &buf);
 
 	if (scsi_status_is_good(req_cmd->status) && (len > 0) &&
 	    SCST_SENSE_VALID(buf) && (!SCST_NO_SENSE(buf))) {
@@ -3814,7 +3816,7 @@ static void scst_complete_request_sense(struct scst_cmd *req_cmd)
 	}
 
 	if (len > 0)
-		scst_put_buf(req_cmd, buf);
+		scst_put_full_buf(req_cmd, buf);
 
 	TRACE_MGMT_DBG("Adding orig cmd %p to head of active "
 		"cmd list", orig_cmd);
@@ -5703,7 +5705,7 @@ int scst_block_generic_dev_done(struct scst_cmd *cmd,
 			int buffer_size, sector_size, sh;
 			uint8_t *buffer;
 
-			buffer_size = scst_get_buf_first(cmd, &buffer);
+			buffer_size = scst_get_full_buf(cmd, &buffer);
 			if (unlikely(buffer_size <= 0)) {
 				if (buffer_size < 0) {
 					PRINT_ERROR("%s: Unable to get the"
@@ -5715,7 +5717,7 @@ int scst_block_generic_dev_done(struct scst_cmd *cmd,
 			sector_size =
 			    ((buffer[4] << 24) | (buffer[5] << 16) |
 			     (buffer[6] << 8) | (buffer[7] << 0));
-			scst_put_buf(cmd, buffer);
+			scst_put_full_buf(cmd, buffer);
 			if (sector_size != 0)
 				sh = scst_calc_block_shift(sector_size);
 			else
@@ -5766,7 +5768,7 @@ int scst_tape_generic_dev_done(struct scst_cmd *cmd,
 	switch (opcode) {
 	case MODE_SENSE:
 	case MODE_SELECT:
-		buffer_size = scst_get_buf_first(cmd, &buffer);
+		buffer_size = scst_get_full_buf(cmd, &buffer);
 		if (unlikely(buffer_size <= 0)) {
 			if (buffer_size < 0) {
 				PRINT_ERROR("%s: Unable to get the buffer (%d)",
@@ -5804,7 +5806,7 @@ int scst_tape_generic_dev_done(struct scst_cmd *cmd,
 	switch (opcode) {
 	case MODE_SENSE:
 	case MODE_SELECT:
-		scst_put_buf(cmd, buffer);
+		scst_put_full_buf(cmd, buffer);
 		break;
 	}
 

scst/src/scst_targ.c

@@ -1713,7 +1713,7 @@ static int scst_report_luns_local(struct scst_cmd *cmd)
 		goto out_err;
 	}
 
-	buffer_size = scst_get_buf_first(cmd, &buffer);
+	buffer_size = scst_get_full_buf(cmd, &buffer);
 	if (unlikely(buffer_size == 0))
 		goto out_compl;
 	else if (unlikely(buffer_size < 0))
@@ -1733,25 +1733,9 @@ static int scst_report_luns_local(struct scst_cmd *cmd)
 		struct list_head *head = &cmd->sess->sess_tgt_dev_list[i];
 		list_for_each_entry(tgt_dev, head, sess_tgt_dev_list_entry) {
 			if (!overflow) {
-				if (offs >= buffer_size) {
-					scst_put_buf(cmd, buffer);
-					buffer_size = scst_get_buf_next(cmd,
-								       &buffer);
-					if (buffer_size > 0) {
-						memset(buffer, 0, buffer_size);
-						offs = 0;
-					} else {
-						overflow = 1;
-						goto inc_dev_cnt;
-					}
-				}
 				if ((buffer_size - offs) < 8) {
-					PRINT_ERROR("Buffer allocated for "
-						"REPORT LUNS command doesn't "
-						"allow to fit 8 byte entry "
-						"(buffer_size=%d)",
-						buffer_size);
-					goto out_put_hw_err;
+					overflow = 1;
+					goto inc_dev_cnt;
 				}
 				*(__force __be64 *)&buffer[offs]
 					= scst_pack_lun(tgt_dev->lun,
@@ -1762,23 +1746,15 @@ inc_dev_cnt:
 			dev_cnt++;
 		}
 	}
-	if (!overflow)
-		scst_put_buf(cmd, buffer);
 
 	/* Set the response header */
-	buffer_size = scst_get_buf_first(cmd, &buffer);
-	if (unlikely(buffer_size == 0))
-		goto out_compl;
-	else if (unlikely(buffer_size < 0))
-		goto out_hw_err;
-
 	dev_cnt *= 8;
 	buffer[0] = (dev_cnt >> 24) & 0xff;
 	buffer[1] = (dev_cnt >> 16) & 0xff;
 	buffer[2] = (dev_cnt >> 8) & 0xff;
 	buffer[3] = dev_cnt & 0xff;
 
-	scst_put_buf(cmd, buffer);
+	scst_put_full_buf(cmd, buffer);
 
 	dev_cnt += 8;
 	if (dev_cnt < cmd->resp_data_len)
@@ -1825,16 +1801,13 @@ out_done:
 	return res;
 
 out_put_err:
-	scst_put_buf(cmd, buffer);
+	scst_put_full_buf(cmd, buffer);
 
 out_err:
 	scst_set_cmd_error(cmd,
 		   SCST_LOAD_SENSE(scst_sense_invalid_field_in_cdb));
 	goto out_compl;
 
-out_put_hw_err:
-	scst_put_buf(cmd, buffer);
-
 out_hw_err:
 	scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
 	goto out_compl;
@@ -1865,7 +1838,7 @@ static int scst_request_sense_local(struct scst_cmd *cmd)
 
 	TRACE(TRACE_SCSI, "%s: Returning stored sense", cmd->op_name);
 
-	buffer_size = scst_get_buf_first(cmd, &buffer);
+	buffer_size = scst_get_full_buf(cmd, &buffer);
 	if (unlikely(buffer_size == 0))
 		goto out_unlock_compl;
 	else if (unlikely(buffer_size < 0))
@@ -1909,7 +1882,7 @@ static int scst_request_sense_local(struct scst_cmd *cmd)
 		memcpy(buffer, tgt_dev->tgt_dev_sense, sl);
 	}
 
-	scst_put_buf(cmd, buffer);
+	scst_put_full_buf(cmd, buffer);
 
 	tgt_dev->tgt_dev_valid_sense_len = 0;
 
@@ -3074,7 +3047,7 @@ static int scst_pre_dev_done(struct scst_cmd *cmd)
 			uint8_t *address;
 			bool err = false;
 
-			length = scst_get_buf_first(cmd, &address);
+			length = scst_get_full_buf(cmd, &address);
 			if (length < 0) {
 				PRINT_ERROR("%s", "Unable to get "
 					"MODE_SENSE buffer");
@@ -3086,7 +3059,7 @@ static int scst_pre_dev_done(struct scst_cmd *cmd)
 				address[2] |= 0x80;   /* Write Protect*/
 			else if (length > 3 && cmd->cdb[0] == MODE_SENSE_10)
 				address[3] |= 0x80;   /* Write Protect*/
-			scst_put_buf(cmd, address);
+			scst_put_full_buf(cmd, address);
 
 			if (err)
 				goto out;
@@ -3104,8 +3077,7 @@ static int scst_pre_dev_done(struct scst_cmd *cmd)
 			int buflen;
 			bool err = false;
 
-			/* ToDo: all pages ?? */
-			buflen = scst_get_buf_first(cmd, &buffer);
+			buflen = scst_get_full_buf(cmd, &buffer);
 			if (buflen > SCST_INQ_BYTE3 && !cmd->tgtt->fake_aca) {
 #ifdef CONFIG_SCST_EXTRACHECKS
 				if (buffer[SCST_INQ_BYTE3] & SCST_INQ_NORMACA_BIT) {
@@ -3125,7 +3097,7 @@ static int scst_pre_dev_done(struct scst_cmd *cmd)
 				err = true;
 			}
 			if (buflen > 0)
-				scst_put_buf(cmd, buffer);
+				scst_put_full_buf(cmd, buffer);
 
 			if (err)
 				goto out;
@@ -3507,14 +3479,16 @@ static int scst_xmit_response(struct scst_cmd *cmd)
 				sg = cmd->sg;
 			if (sg != NULL) {
 				TRACE(TRACE_SND_BOT, "Xmitting data for cmd %p "
-					"(sg_cnt %d, sg %p, sg[0].page %p)",
-					cmd, cmd->tgt_sg_cnt, sg,
-					(void *)sg_page(&sg[0]));
+					"(sg_cnt %d, sg %p, sg[0].page %p, buf %p, "
+					"resp len %d)", cmd, cmd->tgt_sg_cnt,
+					sg, (void *)sg_page(&sg[0]), sg_virt(sg),
+					cmd->resp_data_len);
 				for (i = 0, j = 0; i < cmd->tgt_sg_cnt; ++i, ++j) {
 					if (unlikely(sg_is_chain(&sg[j]))) {
 						sg = sg_chain_ptr(&sg[j]);
 						j = 0;
 					}
+					TRACE(TRACE_SND_BOT, "sg %d", j);
 					PRINT_BUFF_FLAG(TRACE_SND_BOT,
 						"Xmitting sg", sg_virt(&sg[j]),
 						sg[j].length);