Author: trasz
Date: Thu Mar 27 10:15:35 2014
New Revision: 263810
URL: http://svnweb.freebsd.org/changeset/base/263810
Log:
Rework cfiscsi_datamove_in() to obey expected data transfer length
received from the initiator.
Sponsored by: The FreeBSD Foundation
Modified:
head/sys/cam/ctl/ctl_frontend_iscsi.c
Modified: head/sys/cam/ctl/ctl_frontend_iscsi.c
==============================================================================
--- head/sys/cam/ctl/ctl_frontend_iscsi.c Thu Mar 27 09:24:09 2014
(r263809)
+++ head/sys/cam/ctl/ctl_frontend_iscsi.c Thu Mar 27 10:15:35 2014
(r263810)
@@ -2315,8 +2315,8 @@ 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;
@@ -2338,26 +2338,49 @@ 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) {
@@ -2374,22 +2397,43 @@ 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");
@@ -2399,12 +2443,19 @@ 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...
@@ -2427,27 +2478,18 @@ 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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