qemu: Fix reporting of physical capacity for block devices

Qemu reports physical size 0 for block devices. As 15fa84acbb55ebfee6a4
changed the behavior of qemuDomainGetBlockInfo to just query the monitor
this created a regression since we didn't report the size correctly any
more.

This patch adds code to refresh the physical size of a block device by
opening it and seeking to the end and uses it both in
qemuDomainGetBlockInfo and also in qemuDomainGetStatsOneBlock that was
broken since it was introduced in this respect.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1250982
(cherry picked from commit 8dc27259255b79758367789ed272e909bdb56735)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 0a45cdf5e34b3d5a5ecf39d69960329a8d7d0a0e..b70f4498fc66fa969694ec0770748c215444c8b6 100644 (file)
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2156,6 +2156,7 @@ virStorageSourceParseRBDColonString;
 virStorageSourcePoolDefFree;
 virStorageSourcePoolModeTypeFromString;
 virStorageSourcePoolModeTypeToString;
+virStorageSourceUpdateBlockPhysicalSize;
 virStorageTypeFromString;
 virStorageTypeToString;
 

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 641abac917dca0530857bbfcbb7300707aaffa9b..9ffced3c7bfd3413e32ffec9c181454694530733 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -11823,8 +11823,16 @@ qemuDomainGetBlockInfo(virDomainPtr dom,
         info->allocation = entry->wr_highest_offset;
     }
 
+    if (entry->physical) {
+        info->physical = entry->physical;
+    } else {
+        if (virStorageSourceUpdateBlockPhysicalSize(disk->src, true) < 0)
+            goto endjob;
+
+        info->physical = disk->src->physical;
+    }
+
     info->capacity = entry->capacity;
-    info->physical = entry->physical;
 
     ret = 0;
 
@@ -19270,9 +19278,15 @@ qemuDomainGetStatsOneBlock(virQEMUDriverPtr driver,
     if (entry->capacity)
         QEMU_ADD_BLOCK_PARAM_ULL(record, maxparams, block_idx,
                                  "capacity", entry->capacity);
-    if (entry->physical)
+    if (entry->physical) {
         QEMU_ADD_BLOCK_PARAM_ULL(record, maxparams, block_idx,
                                  "physical", entry->physical);
+    } else {
+        if (virStorageSourceUpdateBlockPhysicalSize(src, false) == 0) {
+            QEMU_ADD_BLOCK_PARAM_ULL(record, maxparams, block_idx,
+                                     "physical", src->physical);
+        }
+    }
 
     ret = 0;
  cleanup:

diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index 6c3017cef9e2568e2c8b6bfe79fc4344bedf08ad..2aa1d90d65817ca2c46aaf23250ab4cc85699195 100644 (file)
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -2587,6 +2587,45 @@ virStorageSourceNewFromBacking(virStorageSourcePtr parent)
 }
 
 
+/**
+ * @src: disk source definiton structure
+ * @report: report libvirt errors if set to true
+ *
+ * Updates src->physical for block devices since qemu doesn't report the current
+ * size correctly for them. Returns 0 on success, -1 on error.
+ */
+int
+virStorageSourceUpdateBlockPhysicalSize(virStorageSourcePtr src,
+                                        bool report)
+{
+    int fd = -1;
+    off_t end;
+    int ret = -1;
+
+    if (virStorageSourceGetActualType(src) != VIR_STORAGE_TYPE_BLOCK)
+        return 0;
+
+    if ((fd = open(src->path, O_RDONLY)) < 0) {
+        if (report)
+            virReportSystemError(errno, _("failed to open block device '%s'"),
+                                 src->path);
+        return -1;
+    }
+
+    if ((end = lseek(fd, 0, SEEK_END)) == (off_t) -1) {
+        if (report)
+            virReportSystemError(errno,
+                                 _("failed to seek to end of '%s'"), src->path);
+    } else {
+        src->physical = end;
+        ret = 0;
+    }
+
+    VIR_FORCE_CLOSE(fd);
+    return ret;
+}
+
+
 static char *
 virStorageFileCanonicalizeFormatPath(char **components,
                                      size_t ncomponents,

diff --git a/src/util/virstoragefile.h b/src/util/virstoragefile.h
index aa17a00e54508e1f017396752cb02d8c9bdc460c..b98fe2587181ecb4d45f650773da0b65e5b055ec 100644 (file)
--- a/src/util/virstoragefile.h
+++ b/src/util/virstoragefile.h
@@ -362,6 +362,8 @@ bool virStorageSourceIsLocalStorage(virStorageSourcePtr src);
 bool virStorageSourceIsEmpty(virStorageSourcePtr src);
 void virStorageSourceFree(virStorageSourcePtr def);
 void virStorageSourceBackingStoreClear(virStorageSourcePtr def);
+int virStorageSourceUpdateBlockPhysicalSize(virStorageSourcePtr src,
+                                            bool report);
 virStorageSourcePtr virStorageSourceNewFromBacking(virStorageSourcePtr parent);
 virStorageSourcePtr virStorageSourceCopy(const virStorageSource *src,
                                          bool backingChain)