[ipxe-devel] [INCOMPLETE PATCH] Need assistance - SRP_I_LOGOUT is never run, needs to be
james harvey
jamespharvey20 at gmail.com
Sat Aug 20 03:56:36 UTC 2016
This patch is incomplete. Although it shouldn't hurt to apply, it
prepares for a functional change but does not quite get there, and
would need a bit of polishing.
Problem - Running "dhcp; sanhook <args>; sanboot" propely initiates an
SRP connection, and starts the boot loader. iPXE nevers performs an
SRP_I_LOGOUT, even though it's already defined in include/ipxe/srp.h.
After the kernel has booted and the sBFT parsed, attempting to start
an SRP connection confuses the target machine's kernel, causing SRP
commands to abort for about 10-30 seconds. The only workaround I can
find once booted is to continually repeat attempting the SRP
connection, waiting a second, and retrying. The error I get for 10-30
seconds is:
=====
scsi host7: ib_srp: Got failed path rec status -22
scsi host7: ib_srp: Path record query failed
scsi host7: ib_srp: Connection 0/4 failed
scsi host7: ib_srp: Sending CM DREQ failed
=====
After 10-30 seconds, the target kernel shows:
=====
[ 115.941418] ib_srpt Relogin - closed existing channel
0x1d534b0003c902000002c903004b5275
[ 115.941470] ib_srpt Received CM DREP message for ch
0x1d534b0003c902000002c903004b5275-522.
=====
And the new SRP connection is made. I'm successfully able to make the
SRP connection, and successfully boot with the new root.
With interesting timing, kernel 4.7 just got released in Arch linux 13
days ago. And, in 4.7, ib_srpt was patched to convert to the generic
"RDMA READ/WRITE API" which never closes the existing channel and
allows a new connection, but just blocks a new connection forever.
So the issue started with < kernel 4.7 as just a 10-30 second delay
during bootup, but now with >= 4.7 completely blocks booting. (I'm
going to follow up with a kernel regression, but the best way to
handle this is to close the initial iPXE connection.)
This patch implements the missing srp_initiator_logout(), and modifies
srpdev_close() to call it if srpdev->logged_in is set.
However, in a successful "dhcp; sanhook <args>; sanboot" sequence,
srpdev_close() is never called. (The (3) dbg_printf's I added in
srpdev_close, and (1) in ib_srp.c, never execute - only temporarily
using dbg_printf to avoid building with DEBUG to only see these debug
errors.) The target kernel never gets an SRP_I_LOGOUT command.
srpdev_close is only referenced in src/drivers/block/srp.c in these locations:
(1) In srpdev_deliver, within the label err.
(2) In srp_open(), within the labels err_scsi_open and err_login.
(3) In static struct interface_operation srpdev_socket_op[] as
INTF_OP ( intf_close, struct srp_device *, srpdev_close )
(4) In static struct interface_operation srpdev_scsi_op[] as
INTF_OP ( intf_close, struct srp_device *, srpdev_close )
srpdev_socket_op is only referenced in srp.c within
static struct interface_descriptor srpdev_socket_desc as
INTF_DESC_PASSTHRU ( struct srp_device, socket, srpdev_socket_op, scsi )
srpdev_scsi_op is only referenced in srp.c within
static struct interface_descriptor srpdev_scsi_desc as
INTF_DESC_PASSTHRU ( struct srp_device, scsi, srpdev_scsi_op, socket )
srpdev_scsi_desc and srpdev_socket_desc are only referenced in
srp.c::srp_open, given to intf_init
Looking in net/infiniband/ib_srp.c::ib_srp_close(), it does call
intf_shutdown( &ib_srp->cmrc, rc ) and intf_shutdown ( &ib_srp->srp,
rc ).
At about that point, I started thinking that iPXE probably never knows
that it should fully exit, and that it's probably left in lowmem
forever. Am I right here? I'm not sure there's a point where iPXE
currently knows it can safely fully exit and disable the interrupt
hook. So, I'm looking for guidance.
Do we need to add to the sBFT specification, to include a memory
address of new function which would call srp_initiator_logout with its
struct srp_device *srpdev, if I'm correct that iPXE is basically
staying in low mem forever and never really exiting? Not sure if I'm
understanding that correctly.
Patch is below and attached.
Submitted by: James P. Harvey <jamespharvey20 at gmail.com>
---
src/drivers/block/srp.c | 59 +++++++++++++++++++++++++++++++++++++++++++++
src/net/infiniband/ib_srp.c | 1 +
2 files changed, 60 insertions(+)
diff --git a/src/drivers/block/srp.c b/src/drivers/block/srp.c
index 85c7aa8..8ab4a97 100644
--- a/src/drivers/block/srp.c
+++ b/src/drivers/block/srp.c
@@ -229,15 +229,33 @@ static void srpcmd_close ( struct srp_command
*srpcmd, int rc ) {
* @v srpdev SRP device
* @v rc Reason for close
*/
+static int srp_new_tag ( struct srp_device *srpdev );
+static int srp_initiator_logout ( struct srp_device *srpdev, uint32_t tag );
static void srpdev_close ( struct srp_device *srpdev, int rc ) {
struct srp_command *srpcmd;
struct srp_command *tmp;
+ dbg_printf ( "!srpdev_close()\n" );
if ( rc != 0 ) {
DBGC ( srpdev, "SRP %p closed: %s\n",
srpdev, strerror ( rc ) );
}
+ /* If logged in, attempt logging out */
+ if ( srpdev->logged_in ) {
+ dbg_printf ( "!srpdev->logged_in true\n" );
+ int logout_rc;
+ int tag;
+
+ tag = srp_new_tag ( srpdev );
+ if ( tag < 0 )
+ DBGC ( srpdev, "SRP %p tag %08x invalid tag\n", srpdev, tag );
+ else if ( ( logout_rc = srp_initiator_logout ( srpdev, tag ) ) != 0 )
+ DBGC ( srpdev, "SRP %p tag %08x cannot logout\n", srpdev, tag );
+ } else {
+ dbg_printf ( "!srpdev->logged_in false\n" );
+ }
+
/* Shut down interfaces */
intf_shutdown ( &srpdev->socket, rc );
intf_shutdown ( &srpdev->scsi, rc );
@@ -393,6 +411,47 @@ static int srp_login_rej ( struct srp_device *srpdev,
}
/**
+ * Transmit SRP initiator logout
+ *
+ * @v srpdev SRP device
+ * @v tag Command tag
+ * @ret rc Return status code
+ */
+static int srp_initiator_logout ( struct srp_device *srpdev, uint32_t tag ) {
+ struct io_buffer *iobuf;
+ struct srp_i_logout *i_logout;
+ int rc;
+
+ /* Allocate I/O buffer */
+ iobuf = xfer_alloc_iob ( &srpdev->socket, sizeof ( *i_logout ) );
+ if ( ! iobuf )
+ return -ENOMEM;
+
+ /* Construct initiator logout IU */
+ i_logout = iob_put ( iobuf, sizeof ( *i_logout ) );
+ memset ( i_logout, 0, sizeof ( *i_logout ) );
+ i_logout->type = SRP_I_LOGOUT;
+ i_logout->tag.dwords[0] = htonl ( SRP_TAG_MAGIC );
+ i_logout->tag.dwords[1] = htonl ( tag );
+
+ DBGC ( srpdev, "SRP %p tag %08x I_LOGOUT:\n", srpdev, tag );
+ DBGC_HDA ( srpdev, 0, iobuf->data, iob_len ( iobuf ) );
+
+ /* Send initiator logout IU */
+ if ( ( rc = xfer_deliver_iob ( &srpdev->socket, iobuf ) ) != 0 ) {
+ DBGC ( srpdev, "SRP %p tag %08x could not send I_LOGOUT: "
+ "%s\n", srpdev, tag, strerror ( rc ) );
+ return rc;
+ }
+
+ /* Mark as logged out */
+ srpdev->logged_in = 0;
+ DBGC ( srpdev, "SRP %p logged out\n", srpdev );
+
+ return 0;
+}
+
+/**
* Transmit SRP SCSI command
*
* @v srpdev SRP device
diff --git a/src/net/infiniband/ib_srp.c b/src/net/infiniband/ib_srp.c
index 904a99b..2c718ef 100644
--- a/src/net/infiniband/ib_srp.c
+++ b/src/net/infiniband/ib_srp.c
@@ -106,6 +106,7 @@ static void ib_srp_free ( struct refcnt *refcnt ) {
* @v rc Reason for close
*/
static void ib_srp_close ( struct ib_srp_device *ib_srp, int rc ) {
+ dbg_printf ("ib_srp_close\n" );
/* Shut down interfaces */
intf_shutdown ( &ib_srp->cmrc, rc );
intf_shutdown ( &ib_srp->srp, rc );
--
2.9.0
-------------- next part --------------
A non-text attachment was scrubbed...
Name: fix_srp_close.patch
Type: text/x-patch
Size: 3459 bytes
Desc: not available
URL: <http://lists.ipxe.org/pipermail/ipxe-devel/attachments/20160819/0b8aad82/attachment.bin>
More information about the ipxe-devel
mailing list