libvirt/libvirt-RHEL-virscsi-Introduce-and-use-virSCSIDeviceGetUnprivSGIOSysfsPath.patch

From 1ce4faffcd4616bbcea4d198c3f60cbcfddd784e Mon Sep 17 00:00:00 2001
Message-Id: <1ce4faffcd4616bbcea4d198c3f60cbcfddd784e@dist-git>
From: Michal Privoznik <mprivozn@redhat.com>
Date: Fri, 6 Mar 2020 15:52:23 +0100
Subject: [PATCH] RHEL: virscsi: Introduce and use
 virSCSIDeviceGetUnprivSGIOSysfsPath()

When constructing a path to the 'unpriv_sgio' file of given SCSI
device we don't need to go through /dev/* and major() + minor()
path. The generated path points to
/sys/dev/block/MAJ:MIN/queue/unpriv_sgio which is wrong if the
SCSI device in question is not a block device. We can generate a
different path: /sys/bus/scsi/devices/X:X:X:X/unpriv_sgio where
the file is directly accessible regardless of the SCSI device
type.

https://bugzilla.redhat.com/show_bug.cgi?id=1808390

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Message-Id: <20200306145226.1610708-4-abologna@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/libvirt_private.syms |  1 +
 src/qemu/qemu_conf.c     | 31 +++++++++++++++++++------------
 src/util/virscsi.c       | 19 +++++++++++++++++++
 src/util/virscsi.h       |  5 +++++
 src/util/virutil.c       | 24 ++++++------------------
 src/util/virutil.h       |  2 --
 6 files changed, 50 insertions(+), 32 deletions(-)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 5b76e66e61..2c42e2a5e8 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -3191,6 +3191,7 @@ virSCSIDeviceGetSgName;
 virSCSIDeviceGetShareable;
 virSCSIDeviceGetTarget;
 virSCSIDeviceGetUnit;
+virSCSIDeviceGetUnprivSGIOSysfsPath;
 virSCSIDeviceIsAvailable;
 virSCSIDeviceListAdd;
 virSCSIDeviceListCount;
diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
index 28c334761b..a0b8076d6b 100644
--- a/src/qemu/qemu_conf.c
+++ b/src/qemu/qemu_conf.c
@@ -1506,7 +1506,7 @@ qemuCheckUnprivSGIO(GHashTable *sharedDevices,
     if (!(virHashLookup(sharedDevices, key)))
         return 0;
 
-    if (virGetDeviceUnprivSGIO(device_path, NULL, &val) < 0)
+    if (virGetDeviceUnprivSGIO(sysfs_path, &val) < 0)
         return -1;
 
     /* Error message on failure needs to be handled in caller
@@ -1857,39 +1857,46 @@ qemuSetUnprivSGIO(virDomainDeviceDef *dev)
     virDomainDiskDef *disk = NULL;
     virDomainHostdevDef *hostdev = NULL;
     g_autofree char *sysfs_path = NULL;
-    g_autofree char *hostdev_path = NULL;
-    const char *path = NULL;
     int val = 0;
 
     /* "sgio" is only valid for block disk; cdrom
      * and floopy disk can have empty source.
      */
     if (dev->type == VIR_DOMAIN_DEVICE_DISK) {
+        const char *path;
+
         disk = dev->data.disk;
+        path = virDomainDiskGetSource(disk);
 
         if (disk->device != VIR_DOMAIN_DISK_DEVICE_LUN ||
             !virStorageSourceIsBlockLocal(disk->src))
             return 0;
 
-        path = virDomainDiskGetSource(disk);
+        if (!(sysfs_path = virGetUnprivSGIOSysfsPath(path, NULL)))
+            return -1;
+
     } else if (dev->type == VIR_DOMAIN_DEVICE_HOSTDEV) {
+        virDomainHostdevSubsysSCSI *scsisrc;
+        virDomainHostdevSubsysSCSIHost *scsihostsrc;
+
         hostdev = dev->data.hostdev;
+        scsisrc = &hostdev->source.subsys.u.scsi;
+        scsihostsrc = &scsisrc->u.host;
 
         if (hostdev->source.subsys.u.scsi.protocol ==
             VIR_DOMAIN_HOSTDEV_SCSI_PROTOCOL_TYPE_ISCSI)
             return 0;
 
-        if (!(hostdev_path = qemuGetHostdevPath(hostdev)))
+        if (!(sysfs_path = virSCSIDeviceGetUnprivSGIOSysfsPath(NULL,
+                                                               scsihostsrc->adapter,
+                                                               scsihostsrc->bus,
+                                                               scsihostsrc->target,
+                                                               scsihostsrc->unit)))
             return -1;
-
-        path = hostdev_path;
     } else {
         return 0;
     }
 
-    if (!(sysfs_path = virGetUnprivSGIOSysfsPath(path, NULL)))
-        return -1;
-
     /* By default, filter the SG_IO commands, i.e. set unpriv_sgio to 0.  */
     if (dev->type == VIR_DOMAIN_DEVICE_DISK) {
         if (disk->sgio == VIR_DOMAIN_DEVICE_SGIO_UNFILTERED)
@@ -1909,11 +1916,11 @@ qemuSetUnprivSGIO(virDomainDeviceDef *dev)
     if (virFileExists(sysfs_path) || val == 1) {
         int curr_val;
 
-        if (virGetDeviceUnprivSGIO(path, NULL, &curr_val) < 0)
+        if (virGetDeviceUnprivSGIO(sysfs_path, &curr_val) < 0)
             return -1;
 
         if (curr_val != val &&
-            virSetDeviceUnprivSGIO(path, NULL, val) < 0) {
+            virSetDeviceUnprivSGIO(sysfs_path, val) < 0) {
             return -1;
         }
     }
diff --git a/src/util/virscsi.c b/src/util/virscsi.c
index 6165196423..b437fdcac0 100644
--- a/src/util/virscsi.c
+++ b/src/util/virscsi.c
@@ -302,6 +302,25 @@ virSCSIDeviceGetDevName(const char *sysfs_prefix,
     }
 }
 
+
+char *
+virSCSIDeviceGetUnprivSGIOSysfsPath(const char *sysfs_prefix,
+                                    const char *adapter,
+                                    unsigned int bus,
+                                    unsigned int target,
+                                    unsigned long long unit)
+{
+    unsigned int adapter_id;
+    const char *prefix = sysfs_prefix ? sysfs_prefix : SYSFS_SCSI_DEVICES;
+
+    if (virSCSIDeviceGetAdapterId(adapter, &adapter_id) < 0)
+        return NULL;
+
+    return g_strdup_printf("%s/%d:%u:%u:%llu/unpriv_sgio",
+                           prefix, adapter_id, bus, target, unit);
+}
+
+
 virSCSIDevice *
 virSCSIDeviceNew(const char *sysfs_prefix,
                  const char *adapter,
diff --git a/src/util/virscsi.h b/src/util/virscsi.h
index 65ad15ed76..5721985939 100644
--- a/src/util/virscsi.h
+++ b/src/util/virscsi.h
@@ -40,6 +40,11 @@ char *virSCSIDeviceGetDevName(const char *sysfs_prefix,
                               unsigned int bus,
                               unsigned int target,
                               unsigned long long unit);
+char *virSCSIDeviceGetUnprivSGIOSysfsPath(const char *sysfs_prefix,
+                                          const char *adapter,
+                                          unsigned int bus,
+                                          unsigned int target,
+                                          unsigned long long unit);
 
 virSCSIDevice *virSCSIDeviceNew(const char *sysfs_prefix,
                                   const char *adapter,
diff --git a/src/util/virutil.c b/src/util/virutil.c
index e04f1343d8..b1e37b45c5 100644
--- a/src/util/virutil.c
+++ b/src/util/virutil.c
@@ -1377,18 +1377,13 @@ virGetUnprivSGIOSysfsPath(const char *path,
 
 int
 virSetDeviceUnprivSGIO(const char *path,
-                       const char *sysfs_dir,
                        int unpriv_sgio)
 {
-    char *sysfs_path = NULL;
     char *val = NULL;
     int ret = -1;
     int rc;
 
-    if (!(sysfs_path = virGetUnprivSGIOSysfsPath(path, sysfs_dir)))
-        return -1;
-
-    if (!virFileExists(sysfs_path)) {
+    if (!virFileExists(path)) {
         virReportError(VIR_ERR_OPERATION_INVALID, "%s",
                        _("unpriv_sgio is not supported by this kernel"));
         goto cleanup;
@@ -1396,38 +1391,32 @@ virSetDeviceUnprivSGIO(const char *path,
 
     val = g_strdup_printf("%d", unpriv_sgio);
 
-    if ((rc = virFileWriteStr(sysfs_path, val, 0)) < 0) {
-        virReportSystemError(-rc, _("failed to set %s"), sysfs_path);
+    if ((rc = virFileWriteStr(path, val, 0)) < 0) {
+        virReportSystemError(-rc, _("failed to set %s"), path);
         goto cleanup;
     }
 
     ret = 0;
  cleanup:
-    VIR_FREE(sysfs_path);
     VIR_FREE(val);
     return ret;
 }
 
 int
 virGetDeviceUnprivSGIO(const char *path,
-                       const char *sysfs_dir,
                        int *unpriv_sgio)
 {
-    char *sysfs_path = NULL;
     char *buf = NULL;
     char *tmp = NULL;
     int ret = -1;
 
-    if (!(sysfs_path = virGetUnprivSGIOSysfsPath(path, sysfs_dir)))
-        return -1;
-
-    if (!virFileExists(sysfs_path)) {
+    if (!virFileExists(path)) {
         virReportError(VIR_ERR_OPERATION_INVALID, "%s",
                        _("unpriv_sgio is not supported by this kernel"));
         goto cleanup;
     }
 
-    if (virFileReadAll(sysfs_path, 1024, &buf) < 0)
+    if (virFileReadAll(path, 1024, &buf) < 0)
         goto cleanup;
 
     if ((tmp = strchr(buf, '\n')))
@@ -1435,13 +1424,12 @@ virGetDeviceUnprivSGIO(const char *path,
 
     if (virStrToLong_i(buf, NULL, 10, unpriv_sgio) < 0) {
         virReportError(VIR_ERR_INTERNAL_ERROR,
-                       _("failed to parse value of %s"), sysfs_path);
+                       _("failed to parse value of %s"), path);
         goto cleanup;
     }
 
     ret = 0;
  cleanup:
-    VIR_FREE(sysfs_path);
     VIR_FREE(buf);
     return ret;
 }
diff --git a/src/util/virutil.h b/src/util/virutil.h
index 854b494890..da267c6446 100644
--- a/src/util/virutil.h
+++ b/src/util/virutil.h
@@ -120,10 +120,8 @@ int virGetDeviceID(const char *path,
                    int *maj,
                    int *min) G_GNUC_NO_INLINE;
 int virSetDeviceUnprivSGIO(const char *path,
-                           const char *sysfs_dir,
                            int unpriv_sgio);
 int virGetDeviceUnprivSGIO(const char *path,
-                           const char *sysfs_dir,
                            int *unpriv_sgio);
 char *virGetUnprivSGIOSysfsPath(const char *path,
                                 const char *sysfs_dir);
-- 
2.34.1