Date: Wed, 7 May 2014 06:18:03 +0000 (UTC) From: Edward Tomasz Napierala <trasz@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r265490 - stable/10/sys/cam/ctl Message-ID: <201405070618.s476I3VL083434@svn.freebsd.org>
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Author: trasz Date: Wed May 7 06:18:03 2014 New Revision: 265490 URL: http://svnweb.freebsd.org/changeset/base/265490 Log: MFC r263810: Rework cfiscsi_datamove_in() to obey expected data transfer length received from the initiator. Sponsored by: The FreeBSD Foundation Modified: stable/10/sys/cam/ctl/ctl_frontend_iscsi.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/cam/ctl/ctl_frontend_iscsi.c ============================================================================== --- stable/10/sys/cam/ctl/ctl_frontend_iscsi.c Wed May 7 06:14:41 2014 (r265489) +++ stable/10/sys/cam/ctl/ctl_frontend_iscsi.c Wed May 7 06:18:03 2014 (r265490) @@ -2303,8 +2303,8 @@ cfiscsi_datamove_in(union ctl_io *io) const struct iscsi_bhs_scsi_command *bhssc; struct iscsi_bhs_data_in *bhsdi; struct ctl_sg_entry ctl_sg_entry, *ctl_sglist; - size_t copy_len, len, off; - const char *addr; + size_t len, expected_len, sg_len, buffer_offset; + const char *sg_addr; int ctl_sg_count, error, i; request = io->io_hdr.ctl_private[CTL_PRIV_FRONTEND].ptr; @@ -2326,26 +2326,49 @@ cfiscsi_datamove_in(union ctl_io *io) } /* - * We need to record it so that we can properly report + * This is the total amount of data to be transferred within the current + * SCSI command. We need to record it so that we can properly report * underflow/underflow. */ PDU_TOTAL_TRANSFER_LEN(request) = io->scsiio.kern_total_len; /* - * This is the offset within the current SCSI command; - * i.e. for the first call of datamove(), it will be 0, - * and for subsequent ones it will be the sum of lengths - * of previous ones. + * This is the offset within the current SCSI command; for the first + * call to cfiscsi_datamove() it will be 0, and for subsequent ones + * it will be the sum of lengths of previous ones. It's being + * incremented as we append data to the data segment. */ - off = htonl(io->scsiio.kern_rel_offset); + buffer_offset = io->scsiio.kern_rel_offset; + + /* + * This is the transfer length expected by the initiator. In theory, + * it could be different from the correct amount of data from the SCSI + * point of view, even if that doesn't make any sense. + */ + expected_len = ntohl(bhssc->bhssc_expected_data_transfer_length); +#if 0 + if (expected_len != io->scsiio.kern_total_len) + CFISCSI_SESSION_DEBUG(cs, "expected transfer length = %zd, " + "actual length = %zd", expected_len, + io->scsiio.kern_total_len); +#endif + + if (buffer_offset >= expected_len) { +#if 0 + CFISCSI_SESSION_DEBUG(cs, "buffer_offset = %zd, " + "already sent the expected len", buffer_offset); +#endif + io->scsiio.ext_data_filled = io->scsiio.kern_total_len; + io->scsiio.be_move_done(io); + return; + } i = 0; - addr = NULL; - len = 0; + sg_addr = NULL; + sg_len = 0; response = NULL; bhsdi = NULL; for (;;) { - KASSERT(i < ctl_sg_count, ("i >= ctl_sg_count")); if (response == NULL) { response = cfiscsi_pdu_new_response(request, M_NOWAIT); if (response == NULL) { @@ -2362,22 +2385,43 @@ cfiscsi_datamove_in(union ctl_io *io) bhssc->bhssc_initiator_task_tag; bhsdi->bhsdi_datasn = htonl(PDU_EXPDATASN(request)); PDU_EXPDATASN(request)++; - bhsdi->bhsdi_buffer_offset = htonl(off); + bhsdi->bhsdi_buffer_offset = htonl(buffer_offset); } - if (len == 0) { - addr = ctl_sglist[i].addr; - len = ctl_sglist[i].len; - KASSERT(len > 0, ("len <= 0")); + KASSERT(i < ctl_sg_count, ("i >= ctl_sg_count")); + if (sg_len == 0) { + sg_addr = ctl_sglist[i].addr; + sg_len = ctl_sglist[i].len; + KASSERT(sg_len > 0, ("sg_len <= 0")); } - copy_len = len; - if (response->ip_data_len + copy_len > + len = sg_len; + + /* + * Truncate to maximum data segment length. + */ + KASSERT(response->ip_data_len < cs->cs_max_data_segment_length, + ("max_data_segment_length %zd >= ip_data_len %zd", + response->ip_data_len, cs->cs_max_data_segment_length)); + if (response->ip_data_len + len > cs->cs_max_data_segment_length) - copy_len = cs->cs_max_data_segment_length - + len = cs->cs_max_data_segment_length - response->ip_data_len; - KASSERT(copy_len <= len, ("copy_len > len")); - error = icl_pdu_append_data(response, addr, copy_len, M_NOWAIT); + + /* + * Truncate to expected data transfer length. + */ + KASSERT(buffer_offset + response->ip_data_len < expected_len, + ("%zd >= %zd", buffer_offset + response->ip_data_len, expected_len)); + if (buffer_offset + response->ip_data_len + len > expected_len) { + CFISCSI_SESSION_DEBUG(cs, "truncating from %zd " + "to expected data transfer length %zd", + buffer_offset + response->ip_data_len + len, expected_len); + len = expected_len - (buffer_offset + response->ip_data_len); + } + + KASSERT(len <= sg_len, ("len > sg_len")); + error = icl_pdu_append_data(response, sg_addr, len, M_NOWAIT); if (error != 0) { CFISCSI_SESSION_WARN(cs, "failed to " "allocate memory; dropping connection"); @@ -2387,12 +2431,19 @@ cfiscsi_datamove_in(union ctl_io *io) cfiscsi_session_terminate(cs); return; } - addr += copy_len; - len -= copy_len; - off += copy_len; - io->scsiio.ext_data_filled += copy_len; + sg_addr += len; + sg_len -= len; + buffer_offset += len; + io->scsiio.ext_data_filled += len; + + if (buffer_offset == expected_len) { + /* + * Already have the amount of data the initiator wanted. + */ + break; + } - if (len == 0) { + if (sg_len == 0) { /* * End of scatter-gather segment; * proceed to the next one... @@ -2415,27 +2466,18 @@ cfiscsi_datamove_in(union ctl_io *io) * call to cfiscsi_datamove(), and we want * to set the F flag only on the last of them. */ - if (off == io->scsiio.kern_total_len) + if (buffer_offset == io->scsiio.kern_total_len || + buffer_offset == expected_len) bhsdi->bhsdi_flags |= BHSDI_FLAGS_F; - KASSERT(response->ip_data_len > 0, - ("sending empty Data-In")); cfiscsi_pdu_queue(response); response = NULL; bhsdi = NULL; } } - KASSERT(i == ctl_sg_count - 1, ("missed SG segment")); - KASSERT(len == 0, ("missed data from SG segment")); if (response != NULL) { - if (off == io->scsiio.kern_total_len) { + if (buffer_offset == io->scsiio.kern_total_len || + buffer_offset == expected_len) bhsdi->bhsdi_flags |= BHSDI_FLAGS_F; -#if 0 - } else { - CFISCSI_SESSION_DEBUG(cs, "not setting the F flag; " - "have %zd, need %zd", off, - (size_t)io->scsiio.kern_total_len); -#endif - } KASSERT(response->ip_data_len > 0, ("sending empty Data-In")); cfiscsi_pdu_queue(response); }
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