Re: [libvirt] [PATCH v2] storage: Allow to delete device mapper disk partition

9 Feb 2011


      于 2011年02月09日 00:52, Eric Blake 写道:
...
On 02/08/2011 03:30 AM, Osier Yang wrote:
...
@@ -1739,11 +1746,23 @@ if test "$with_storage_disk" = "yes" ||
      with_storage_disk=yes
    fi
+  if test "$DMSETUP_FOUND" = "no" ; then
+    if test "$with_storage_disk" = "yes" ; then
+      AC_MSG_ERROR([We need dmsetup for disk storage driver])
+    else
+      with_storage_disk=no
+    fi
+  else
+    with_storage_disk=yes
+  fi
Logic is still not right here.  You have two separate if clauses that
both try to convert with_storage_disk=check into
with_storage_disk=yes/no, but after the first block has run, the second
block never knwos that with_storage_disk used to be check.
It needs to be something like:
if test "$with_storage_disk" = "yes"&&
    test "$PARTED_FOUND:$DMSETUP_FOUND" != "yes:yes"; then
   AC_MSG_ERROR([Need both parted and dmsetup for disk storage driver])
fi
if test "$with_storage_disk" = "check"; then
   if test "$PARTED_FOUND:$DMSETUP_FOUND" != "yes:yes"; then
     with_storage_disk=no
   else
     with_storage_disk=yes
   fi
fi
That is, if with_storage_disk is yes, then insist that both programs be
found; if with_storage_disk is check, then set with_storage_disk exactly
once based on the presence of both programs.
Oops, yes, didn't pay much attention here. :-)
...
So we'll need to see a v3.
...
@@ -895,6 +896,8 @@ virSetCloseExec;
  virSetNonBlock;
  virSetUIDGID;
  virSkipSpaces;
+virStrcpy;
+virStrncpy;
  virStrToDouble;
  virStrToLong_i;
  virStrToLong_l;
@@ -902,8 +905,6 @@ virStrToLong_ll;
  virStrToLong_ui;
  virStrToLong_ul;
  virStrToLong_ull;
-virStrcpy;
-virStrncpy;
Hmm, you must have used emacs sorting while in LC_ALL=en_US.UTF-8
instead of LC_ALL=C.  Personally, I leave LC_ALL undefined,
LANG=en_US.UTF-8, and LC_COLLATE=C, to get byte-value sorting
everywhere.  I'm not sure if it makes sense to keep these hunks.
...
@@ -660,38 +662,46 @@ virStorageBackendDiskDeleteVol(virConnectPtr conn ATTRIBUTE_UNUSED,
      srcname = basename(pool->def->source.devices[0].path);
      DEBUG("devname=%s, srcname=%s", devname, srcname);
-    if (!STRPREFIX(devname, srcname)) {
+    if (!virIsDevMapperDevice(devpath)&&  !STRPREFIX(devname, srcname)) {
Let's swap the order of the conditionals.  STRPREFIX is potentially
faster than virIsDevMapperDevice (since the latter calls stat() directly
and who knows what other syscalls in dm_is_dm_major).
yes, carefully reviewing, will update.
...
...
virStorageReportError(VIR_ERR_INTERNAL_ERROR,
                                _("Volume path '%s' did not start with parent "
                                  "pool source device name."), devname);
          goto cleanup;
      }
-    part_num = devname + strlen(srcname);
+    if (!virIsDevMapperDevice(devpath)) {
And, since it involves syscalls, can we cache the answer in a local bool
variable, rather than calling it twice?
will update
...
...
+    } else {
+        cmd = virCommandNew(DMSETUP);
+        virCommandAddArgList(cmd, "remove", "--force", devpath, NULL);
If you want, you can use virCommandNewArgList instead of
virCommandNew/virCommandAddArgList.
It's more compact, so, okay.
...
...
+bool
+virIsDevMapperDevice(const char *devname)
+{
+    struct stat buf;
+
+    if (devname&&
+        !stat(devname,&buf)&&
+        dm_is_dm_major(major(buf.st_rdev)))
major() is not required by POSIX; are we guaranteed that this will
compile everywhere?  Also, are we sure that st_rdev is defined on all
file types, or should we add an extra condition that S_ISBLK(buf.st_mode)?


    