From 3e687d8072f3ed53ae727ec2cb99ae56dbcdf02b Mon Sep 17 00:00:00 2001

From: Peter Jones <pjones@redhat.com>

Date: Mon, 1 Oct 2018 14:35:01 -0400

Subject: [PATCH 39/39] sas: handle port expanders at all.

Signed-off-by: Peter Jones <pjones@redhat.com>

---

 src/linux-ata.c  |   3 +-

 src/linux-sas.c  | 168 ++++++++++++++++++++++++++++++++++++++++++-----

 src/linux-scsi.c | 105 +++++++++++++++++++++++++----

 src/linux.h      |   6 +-

 4 files changed, 250 insertions(+), 32 deletions(-)

diff --git a/src/linux-ata.c b/src/linux-ata.c

index 32cb99361e5..43e5f4c5d23 100644

--- a/src/linux-ata.c

+++ b/src/linux-ata.c

@@ -114,7 +114,8 @@ parse_ata(struct device *dev, const char *current, const char *root UNUSED)

         pos = parse_scsi_link(host + 1, &scsi_host,

                               &scsi_bus, &scsi_device,

-                              &scsi_target, &scsi_lun);

+                              &scsi_target, &scsi_lun,

+                              NULL, NULL, NULL);

         if (pos < 0)

                 return -1;

diff --git a/src/linux-sas.c b/src/linux-sas.c

index 4d77d39a24d..bb04fe83064 100644

--- a/src/linux-sas.c

+++ b/src/linux-sas.c

@@ -28,6 +28,91 @@

 #include "efiboot.h"

+static int

+get_port_expander_sas_address(uint64_t *sas_address, uint32_t scsi_host,

+                              uint32_t local_port_id,

+                              uint32_t remote_port_id, uint32_t remote_scsi_target)

+{

+        uint8_t *filebuf = NULL;

+        int rc;

+

+        /*

+         * We find sas_address via this insanity:

+         * /sys/class/scsi_host/host2 -> ../../devices/pci0000:74/0000:74:02.0/host2/scsi_host/host2

+         * /sys/devices/pci0000:74/0000:74:02.0/host2/scsi_host/host2/device -> ../../../host2

+         * /sys/devices/pci0000:74/0000:74:02.0/host2/device -> ../../../host2

+         * /sys/devices/host2/port-2:0/expander-2:0/sas_device/expander-2:0/sas_address

+         *

+         * But since host2 is always host2, we can skip most of that and just

+         * go for:

+         * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/sas_device/end_device-2:0:2/sas_address

+        */

+

+#if 0 /* previously thought this was right, but it's the expander's address, not the target's address */

+        /*

+         * /sys/class/scsi_host/host2/device/port-2:0/expander-2:0/sas_device/expander-2:0/sas_address

+         * ... I think.  I would have expected that to be port-2:0:0 and I

+         * don't understand why it isn't. (I do now; this is the expander not

+         * the port.)

+         */

+

+        debug("looking for /sys/class/scsi_host/host%d/device/port-%d:%d/expander-%d:%d/sas_device/expander-%d:%d/sas_address",

+              scsi_host, scsi_host, port_id, scsi_host, remote_scsi_target, scsi_host, remote_scsi_target);

+        rc = read_sysfs_file(&filebuf,

+                             "class/scsi_host/host%d/device/port-%d:%d/expander-%d:%d/sas_device/expander-%d:%d/sas_address",

+                             scsi_host, scsi_host, port_id, scsi_host, remote_scsi_target, scsi_host, remote_scsi_target);

+        if (rc < 0 || filebuf == NULL) {

+                debug("didn't find it.");

+                return -1;

+        }

+#else

+        debug("looking for /sys/class/scsi_host/host%d/device/port-%d:%d/expander-%d:%d/port-%d:%d:%d/end_device-%d:%d:%d/sas_device/end_device-%d:%d:%d/sas_address",

+              scsi_host,

+              scsi_host, local_port_id,

+              scsi_host, remote_scsi_target,

+              scsi_host, remote_scsi_target, remote_port_id,

+              scsi_host, remote_scsi_target, remote_port_id,

+              scsi_host, remote_scsi_target, remote_port_id);

+        rc = read_sysfs_file(&filebuf,

+                             "class/scsi_host/host%d/device/port-%d:%d/expander-%d:%d/port-%d:%d:%d/end_device-%d:%d:%d/sas_device/end_device-%d:%d:%d/sas_address",

+                             scsi_host,

+                             scsi_host, local_port_id,

+                             scsi_host, remote_scsi_target,

+                             scsi_host, remote_scsi_target, remote_port_id,

+                             scsi_host, remote_scsi_target, remote_port_id,

+                             scsi_host, remote_scsi_target, remote_port_id);

+        if (rc < 0 || filebuf == NULL) {

+                debug("didn't find it.");

+                return -1;

+        }

+#endif

+

+        rc = sscanf((char *)filebuf, "%"PRIx64, sas_address);

+        if (rc != 1)

+                return -1;

+

+        return 0;

+}

+

+static int

+get_local_sas_address(uint64_t *sas_address, struct device *dev)

+{

+        int rc;

+        char *filebuf = NULL;

+

+        rc = read_sysfs_file(&filebuf,

+                             "class/block/%s/device/sas_address",

+                             dev->disk_name);

+        if (rc < 0 || filebuf == NULL)

+                return -1;

+

+        rc = sscanf((char *)filebuf, "%"PRIx64, sas_address);

+        if (rc != 1)

+                return -1;

+

+        return 0;

+}

+

 /*

  * support for SAS devices

  *

@@ -43,6 +128,24 @@

  * /sys/class/block/sdc/device/sas_address

  *

  * I'm not sure at the moment if they're the same or not.

+ *

+ * There are also other devices that look like:

+ *

+ * 8:0 -> ../../devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda

+ * 8:1 -> ../../devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1

+ *

+ * /sys/dev/block/8:0/device -> ../../../2:0:0:0

+ *

+ * This exists:

+ *

+ * /sys/class/scsi_host/host2 -> ../../devices/pci0000:74/0000:74:02.0/host2/scsi_host/host2

+ * /sys/devices/pci0000:74/0000:74:02.0/host2/scsi_host/host2/device -> ../../../host2

+ * /sys/devices/pci0000:74/0000:74:02.0/host2/device -> ../../../host2

+ * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/sas_device/expander-2:0/sas_address

+ *

+ * but the device doesn't actually have a sas_host_address, because it's on a

+ * port expander, and sas_address doesn't directly exist under /sys/class/

+ * anywhere.

  */

 static ssize_t

 parse_sas(struct device *dev, const char *current, const char *root UNUSED)

@@ -50,16 +153,19 @@ parse_sas(struct device *dev, const char *current, const char *root UNUSED)

         struct stat statbuf = { 0, };

         int rc;

         uint32_t scsi_host, scsi_bus, scsi_device, scsi_target;

+        uint32_t local_port_id = 0, remote_port_id = 0;

+        uint32_t remote_scsi_target = 0;

         uint64_t scsi_lun;

         ssize_t pos;

-        uint8_t *filebuf = NULL;

-        uint64_t sas_address;

+        uint64_t sas_address = 0;

         debug("entry");

         pos = parse_scsi_link(current, &scsi_host,

                               &scsi_bus, &scsi_device,

-                              &scsi_target, &scsi_lun);

+                              &scsi_target, &scsi_lun,

+                              &local_port_id, &remote_port_id,

+                              &remote_scsi_target);

         /*

          * If we can't parse the scsi data, it isn't a sas device, so return 0

          * not error.

@@ -71,6 +177,7 @@ parse_sas(struct device *dev, const char *current, const char *root UNUSED)

          * Make sure it has the actual /SAS/ bits before we continue

          * validating all this junk.

          */

+        debug("looking for /sys/class/scsi_host/host%d/host_sas_address", scsi_host);

         rc = sysfs_stat(&statbuf,

                         "class/scsi_host/host%d/host_sas_address",

                         scsi_host);

@@ -79,21 +186,48 @@ parse_sas(struct device *dev, const char *current, const char *root UNUSED)

          * 0 not error. Later errors mean it is an ata device, but we can't

          * parse it right, so they return -1.

          */

-        if (rc < 0)

-                return 0;

+        if (rc < 0) {

+                debug("didn't find it.");

+                /*

+                 * If it's on a port expander, it won't have the

+                 * host_sas_address, so we need to check if it's a sas_host

+                 * instead.

+                 * It may work to just check this to begin with, but I don't

+                 * have such a device in front of me right now.

+                 */

+                debug("looking for /sys/class/sas_host/host%d", scsi_host);

+                rc = sysfs_stat(&statbuf,

+                                "class/sas_host/host%d", scsi_host);

+                if (rc < 0) {

+                        debug("didn't find it.");

+                        return 0;

+                }

+                debug("found it.");

-        /*

-         * we also need to get the actual sas_address from someplace...

-         */

-        rc = read_sysfs_file(&filebuf,

-                             "class/block/%s/device/sas_address",

-                             dev->disk_name);

-        if (rc < 0 || filebuf == NULL)

-                return -1;

-

-        rc = sscanf((char *)filebuf, "%"PRIx64, &sas_address);

-        if (rc != 1)

-                return -1;

+                /*

+                 * So it *is* a sas_host, and we have to fish the sas_address

+                 * from the remote port

+                 */

+                rc = get_port_expander_sas_address(&sas_address, scsi_host,

+                                                   local_port_id,

+                                                   remote_port_id,

+                                                   remote_scsi_target);

+                if (rc < 0) {

+                        debug("Couldn't find port expander sas address");

+                        return 0;

+                }

+        } else {

+                /*

+                 * we also need to get the actual sas_address from someplace...

+                 */

+                debug("found it.");

+                rc = get_local_sas_address(&sas_address, dev);

+                if (rc < 0) {

+                        debug("Couldn't find sas address");

+                        return 0;

+                }

+        }

+        debug("sas address is 0x%"PRIx64, sas_address);

         dev->sas_info.sas_address = sas_address;

diff --git a/src/linux-scsi.c b/src/linux-scsi.c

index 2e4f710badf..a5e81cf9cb6 100644

--- a/src/linux-scsi.c

+++ b/src/linux-scsi.c

@@ -38,7 +38,9 @@

 ssize_t HIDDEN

 parse_scsi_link(const char *current, uint32_t *scsi_host,

                 uint32_t *scsi_bus, uint32_t *scsi_device,

-                uint32_t *scsi_target, uint64_t *scsi_lun)

+                uint32_t *scsi_target, uint64_t *scsi_lun,

+                uint32_t *local_port_id, uint32_t *remote_port_id,

+                uint32_t *remote_target_id)

 {

         int rc;

         int sz = 0;

@@ -70,11 +72,32 @@ parse_scsi_link(const char *current, uint32_t *scsi_host,

          * /sys/block/sdc/device looks like:

          * device-> ../../../4:2:0:0

          *

+         * OR

+         *

+         * 8:0 -> ../../devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda

+         * 8:1 -> ../../devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1

+         *

+         * /sys/block/sda/device looks like:

+         * device -> ../../../2:0:0:0 *

+         *

+         * sas_address exists, but it's hard to find:

+         * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/sas_device/expander-2:0/sas_address

+         * but sas_host_address is nowhere to be found, and sas_address

+         * doesn't directly exist under /sys/class/ anywhere.  So you actually

+         * have to go to

+         * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/sas_device/expander-2:0/sas_address

+         * and chop that off to

+         * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/

+         * and then add a bunch of port and end device crap to it to get:

+         * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/sas_device/end_device-2:0:2/sas_address

+

          */

         /*

          * So we start when current is:

          * host4/port-4:0/end_device-4:0/target4:0:0/4:0:0:0/block/sdc/sdc1

+         * or

+         * host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1

          */

         uint32_t tosser0, tosser1, tosser2;

@@ -91,6 +114,14 @@ parse_scsi_link(const char *current, uint32_t *scsi_host,

         sz += pos0;

         pos0 = 0;

+        /*

+         * We might have this next:

+         * port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1

+         * or:

+         * port-2:0/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1

+         * or maybe (not sure):

+         * port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1

+         */

         debug("searching for port-4:0 or port-4:0:0");

         rc = sscanf(current+sz, "port-%d:%d%n:%d%n", &tosser0,

                     &tosser1, &pos0, &tosser2, &pos1);

@@ -100,6 +131,52 @@ parse_scsi_link(const char *current, uint32_t *scsi_host,

         if (rc == 2 || rc == 3) {

                 sz += pos0;

                 pos0 = 0;

+                if (local_port_id && rc == 2)

+                        *local_port_id = tosser1;

+                if (remote_port_id && rc == 3)

+                        *remote_port_id = tosser2;

+

+                if (current[sz] == '/')

+                        sz += 1;

+

+                /*

+                 * We might have this next:

+                 * expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1

+                 *                       ^ port id

+                 *                     ^ scsi target id

+                 *                   ^ host number

+                 *          ^ host number

+                 * We don't actually care about either number in expander-.../,

+                 * because they're replicated in all the other places.  We just need

+                 * to get past it.

+                 */

+                debug("searching for expander-4:0/");

+                rc = sscanf(current+sz, "expander-%d:%d/%n", &tosser0, &tosser1, &pos0);

+                debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);

+                arrow(LOG_DEBUG, spaces, 9, pos0, rc, 2);

+                if (rc == 2) {

+                        if (!remote_target_id) {

+                                efi_error("Device is PHY is a remote target, but remote_target_id is NULL");

+                                return -1;

+                        }

+                        *remote_target_id = tosser1;

+                        sz += pos0;

+                        pos0 = 0;

+

+                        /*

+                         * if we have that, we should have a 3-part port next

+                         */

+                        debug("searching for port-2:0:2/");

+                        rc = sscanf(current+sz, "port-%d:%d:%d/%n", &tosser0, &tosser1, &tosser2, &pos0);

+                        debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);

+                        arrow(LOG_DEBUG, spaces, 9, pos0, rc, 3);

+                        if (rc != 3) {

+                                efi_error("Couldn't parse port expander port string");

+                                return -1;

+                        }

+                        sz += pos0;

+                }

+                pos0 = 0;

                 /* next:

                  *    /end_device-4:0

@@ -107,22 +184,24 @@ parse_scsi_link(const char *current, uint32_t *scsi_host,

                  * awesomely these are the exact same fields that go into port-blah,

                  * but we don't care for now about any of them anyway.

                  */

-                debug("searching for /end_device-4:0/ or /end_device-4:0:0/");

-                rc = sscanf(current + sz, "/end_device-%d:%d%n", &tosser0, &tosser1, &pos0);

+                debug("searching for end_device-4:0/ or end_device-4:0:0/");

+                rc = sscanf(current + sz, "end_device-%d:%d%n", &tosser0, &tosser1, &pos0);

                 debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);

-                arrow(LOG_DEBUG, spaces, 9, pos0, rc, 2);

                 if (rc != 2)

                         return -1;

-                sz += pos0;

-                pos0 = 0;

-                rc = sscanf(current + sz, ":%d%n", &tosser0, &pos0);

-                debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);

-                arrow(LOG_DEBUG, spaces, 9, pos0, rc, 2);

+                pos1 = 0;

+                rc = sscanf(current + sz + pos0, ":%d%n", &tosser2, &pos1);

+                arrow(LOG_DEBUG, spaces, 9, pos0, rc + 2, 2);

+                arrow(LOG_DEBUG, spaces, 9, pos0 + pos1, rc + 2, 3);

                 if (rc != 0 && rc != 1)

                         return -1;

-                sz += pos0;

-                pos0 = 0;

+                if (remote_port_id && rc == 1)

+                        *remote_port_id = tosser2;

+                if (local_port_id && rc == 0)

+                        *local_port_id = tosser1;

+                sz += pos0 + pos1;

+                pos0 = pos1 = 0;

                 if (current[sz] == '/')

                         sz += 1;

@@ -156,6 +235,7 @@ parse_scsi_link(const char *current, uint32_t *scsi_host,

                 return -1;

         sz += pos0;

+        debug("returning %d", sz);

         return sz;

 }

@@ -191,7 +271,8 @@ parse_scsi(struct device *dev, const char *current, const char *root UNUSED)

         sz = parse_scsi_link(current, &scsi_host,

                               &scsi_bus, &scsi_device,

-                              &scsi_target, &scsi_lun);

+                              &scsi_target, &scsi_lun,

+                              NULL, NULL, NULL);

         if (sz < 0)

                 return 0;

diff --git a/src/linux.h b/src/linux.h

index 7c7ea91e771..43a9b7899f5 100644

--- a/src/linux.h

+++ b/src/linux.h

@@ -267,8 +267,10 @@ struct dev_probe {

 };

 extern ssize_t parse_scsi_link(const char *current, uint32_t *host,

-                                      uint32_t *bus, uint32_t *device,

-                                      uint32_t *target, uint64_t *lun);

+                               uint32_t *bus, uint32_t *device,

+                               uint32_t *target, uint64_t *lun,

+                               uint32_t *local_port_id, uint32_t *remote_port_id,

+                               uint32_t *remote_target_id);

 /* device support implementations */

 extern struct dev_probe pmem_parser;

-- 

2.17.1