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  1. 12 7月, 2008 2 次提交
  3. 19 4月, 2008 1 次提交
  5. 08 2月, 2008 1 次提交
  7. 31 1月, 2008 1 次提交
    • J
      [SCSI] remove use_sg_chaining · d3f46f39
      由 James Bottomley 提交于 
      With the sg table code, every SCSI driver is now either chain capable
or broken (or has sg_tablesize set so chaining is never activated), so
there's no need to have a check in the host template.

Also tidy up the code by moving the scatterlist size defines into the
SCSI includes and permit the last entry of the scatterlist pools not
to be a power of two.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
      d3f46f39
  9. 12 1月, 2008 13 次提交
  11. 15 11月, 2007 1 次提交
    • T
      [SCSI] iscsi_tcp: fix potential lockup with write commands · 505f76b3
      由 Tony Battersby 提交于 
      There is a race condition in iscsi_tcp.c that may cause it to forget
that it received a R2T from the target.  This race may cause a data-out
command (such as a write) to lock up.  The race occurs here:

static int
iscsi_send_unsol_pdu(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
	int rc;

	if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
		BUG_ON(!ctask->unsol_count);
		tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR; <---- RACE
		...

static int
iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
	...
	tcp_ctask->xmstate |= XMSTATE_SOL_HDR_INIT; <---- RACE
	...

While iscsi_xmitworker() (called from scsi_queue_work()) is preparing to
send unsolicited data, iscsi_tcp_data_recv() (called from
tcp_read_sock()) interrupts it upon receipt of a R2T from the target.
Both contexts do read-modify-write of tcp_ctask->xmstate.  Usually, gcc
on x86 will make &= and |= atomic on UP (not guaranteed of course), but
in this case iscsi_send_unsol_pdu() reads the value of xmstate before
clearing the bit, which causes gcc to read xmstate into a CPU register,
test it, clear the bit, and then store it back to memory.  If the recv
interrupt happens during this sequence, then the XMSTATE_SOL_HDR_INIT
bit set by the recv interrupt will be lost, and the R2T will be
forgotten.

The patch below (against 2.6.24-rc1) converts accesses of xmstate to use
set_bit, clear_bit, and test_bit instead of |= and &=.  I have tested
this patch and verified that it fixes the problem.  Another possible
approach would be to hold a lock during most of the rx/tx setup and
post-processing, and drop the lock only for the actual rx/tx.
Signed-off-by: NTony Battersby <tonyb@cybernetics.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
      505f76b3
  13. 27 10月, 2007 1 次提交
  15. 24 10月, 2007 1 次提交
  17. 23 10月, 2007 1 次提交
  19. 27 7月, 2007 2 次提交
  21. 21 7月, 2007 1 次提交
  23. 20 7月, 2007 1 次提交
  25. 18 6月, 2007 1 次提交
  27. 03 6月, 2007 7 次提交
  29. 02 6月, 2007 6 次提交