From 8fcdc238ce1b492e1f57a73a2ce4131d63f45397 Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Tue, 26 Jul 2022 18:53:39 -0500 Subject: [PATCH] scsi: target: Remove XDWRITEREAD emulated support This patch removes XDWRITEREAD support because it never fully worked when it was added in the initial LIO merge and it's been fully broken since 2013 from commit a2890087499a ("target: Add compare_and_write_post() completion callback fall through"). The two issues above are: 1. XDWRITEREAD support was just never completed when LIO was merged. We never did the DISABLE WRITE check and so we never write data out. 2. Since the commit above, we never complete the command. After we do the XOR, we return from xdreadwrite_callback and that's it. We never send a response for the command, so the command will always time out and fail. Since this has been fully broken for almost nine years this patch just removes emulated support. Link: https://lore.kernel.org/r/20220726235339.14551-1-michael.christie@oracle.com Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen --- drivers/target/target_core_sbc.c | 99 ---------------------------------------- 1 file changed, 99 deletions(-) diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index ca1b231..786ca58 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -339,68 +339,6 @@ sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags, struct sbc_ops *op return 0; } -static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success, - int *post_ret) -{ - unsigned char *buf, *addr; - struct scatterlist *sg; - unsigned int offset; - sense_reason_t ret = TCM_NO_SENSE; - int i, count; - - if (!success) - return 0; - - /* - * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command - * - * 1) read the specified logical block(s); - * 2) transfer logical blocks from the data-out buffer; - * 3) XOR the logical blocks transferred from the data-out buffer with - * the logical blocks read, storing the resulting XOR data in a buffer; - * 4) if the DISABLE WRITE bit is set to zero, then write the logical - * blocks transferred from the data-out buffer; and - * 5) transfer the resulting XOR data to the data-in buffer. - */ - buf = kmalloc(cmd->data_length, GFP_KERNEL); - if (!buf) { - pr_err("Unable to allocate xor_callback buf\n"); - return TCM_OUT_OF_RESOURCES; - } - /* - * Copy the scatterlist WRITE buffer located at cmd->t_data_sg - * into the locally allocated *buf - */ - sg_copy_to_buffer(cmd->t_data_sg, - cmd->t_data_nents, - buf, - cmd->data_length); - - /* - * Now perform the XOR against the BIDI read memory located at - * cmd->t_mem_bidi_list - */ - - offset = 0; - for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) { - addr = kmap_atomic(sg_page(sg)); - if (!addr) { - ret = TCM_OUT_OF_RESOURCES; - goto out; - } - - for (i = 0; i < sg->length; i++) - *(addr + sg->offset + i) ^= *(buf + offset + i); - - offset += sg->length; - kunmap_atomic(addr); - } - -out: - kfree(buf); - return ret; -} - static sense_reason_t sbc_execute_rw(struct se_cmd *cmd) { @@ -927,47 +865,10 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; cmd->execute_cmd = sbc_execute_rw; break; - case XDWRITEREAD_10: - if (cmd->data_direction != DMA_TO_DEVICE || - !(cmd->se_cmd_flags & SCF_BIDI)) - return TCM_INVALID_CDB_FIELD; - sectors = transport_get_sectors_10(cdb); - - if (sbc_check_dpofua(dev, cmd, cdb)) - return TCM_INVALID_CDB_FIELD; - - cmd->t_task_lba = transport_lba_32(cdb); - cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; - - /* - * Setup BIDI XOR callback to be run after I/O completion. - */ - cmd->execute_cmd = sbc_execute_rw; - cmd->transport_complete_callback = &xdreadwrite_callback; - break; case VARIABLE_LENGTH_CMD: { u16 service_action = get_unaligned_be16(&cdb[8]); switch (service_action) { - case XDWRITEREAD_32: - sectors = transport_get_sectors_32(cdb); - - if (sbc_check_dpofua(dev, cmd, cdb)) - return TCM_INVALID_CDB_FIELD; - /* - * Use WRITE_32 and READ_32 opcodes for the emulated - * XDWRITE_READ_32 logic. - */ - cmd->t_task_lba = transport_lba_64_ext(cdb); - cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; - - /* - * Setup BIDI XOR callback to be run during after I/O - * completion. - */ - cmd->execute_cmd = sbc_execute_rw; - cmd->transport_complete_callback = &xdreadwrite_callback; - break; case WRITE_SAME_32: sectors = transport_get_sectors_32(cdb); if (!sectors) { -- 2.7.4