8:26 a.m.
https://bugzilla.redhat.com/show_bug.cgi?id=1265694
Commit id '020135dc' didn't quite get the algorithm correct when a
device mapper source ended with a non numeric value (e.g. ends with
an alphabet value).
This patch modifies the 'part_separator' logic to add the "p" separator
to the attempted target path name only when specified as part_separator='yes'.
For a source name that already ends with a number, the logic doesn't change
as the part separator would need to be there.
For a source name that ends with something other than a number, this allows
the possibility that a "p" separator can be added. The default for one of
these source devices is to not add the separator.
The key for device mapper and the need for a partition separator "p" is
the presence of a number in the last character of the device name link
in /dev/mapper. A name such as "/dev/mapper/mpatha1" would generate
a "/dev/mapper/mpatha1p1" partition, while "/dev/mapper/mpatha" would
generate partition "/dev/mapper/mpatha1". Similarly for a device
mapper entry not using friendly names or an alias, a device such as
"/dev/mapper/3600a0b80005b10ca00005ad656fd8d93" would generate a
paritition "/dev/mapper/3600a0b80005b10ca00005ad656fd8d93p1", while
a device such as "/dev/mapper/3600a0b80005b10ca00005e115729093f" would
generate a partition "/dev/mapper/3600a0b80005b10ca00005e115729093f1".
The long number is the WWID of the device. It's also possible to assign
an alias for a device mapper entry, that alias follows the same rules
with respect to ending with a number or not when adding a "p" to create
the target device path.
Signed-off-by: John Ferlan <jferlan(a)redhat.com>
---
docs/formatstorage.html.in | 18 +++++-------------
src/storage/parthelper.c | 11 ++++++-----
src/storage/storage_backend_disk.c | 9 +++++----
3 files changed, 16 insertions(+), 22 deletions(-)
diff --git a/docs/formatstorage.html.in b/docs/formatstorage.html.in
index 0356182..94277a1 100644
--- a/docs/formatstorage.html.in
+++ b/docs/formatstorage.html.in
@@ -134,19 +134,11 @@
<code>path</code> may be supplied. Valid values for the attribute
may be either "yes" or "no". This attribute is to be used for
a
<code>disk</code> pool type using a <code>path</code> to
a
- device mapper multipath device configured to utilize either
- 'user_friendly_names' or a custom 'alias' name in the
- /etc/multipath.conf. The attribute directs libvirt to not
- generate device volume names with the partition character "p".
- By default, when libvirt generates the partition names for
- device mapper multipath devices it will add a "p" path separator
- to the device name before adding the partition number. For example,
- a <code>device path</code> of '/dev/mapper/mpatha' libvirt
would
- generate partition names of '/dev/mapper/mpathap1',
- '/dev/mapper/mpathap2', etc. for each partition found. With
- this attribute set to "no", libvirt will not append the "p"
to
- the name unless it ends with a number thus generating names
- of '/dev/mapper/mpatha1', '/dev/mapper/mpatha2', etc.
+ device mapper multipath device. Setting the attribute to "yes"
+ causes libvirt to attempt to generate and find target volume path's
+ using a "p" separator. The default algorithm used by device mapper
+ is to add the "p" separator only when the source device path ends
+ with a number.
<span class="since">Since
1.3.1</span></p></dd>
<dt><code>dir</code></dt>
<dd>Provides the source for pools backed by directories (pool
diff --git a/src/storage/parthelper.c b/src/storage/parthelper.c
index 6695f23..d81b177 100644
--- a/src/storage/parthelper.c
+++ b/src/storage/parthelper.c
@@ -69,7 +69,7 @@ int main(int argc, char **argv)
const char *path;
char *canonical_path;
const char *partsep;
- bool devmap_nopartsep = false;
+ bool devmap_partsep = false;
if (virGettextInitialize() < 0)
exit(EXIT_FAILURE);
@@ -77,7 +77,7 @@ int main(int argc, char **argv)
if (argc == 3 && STREQ(argv[2], "-g")) {
cmd = DISK_GEOMETRY;
} else if (argc == 3 && STREQ(argv[2], "-p")) {
- devmap_nopartsep = true;
+ devmap_partsep = true;
} else if (argc != 2) {
fprintf(stderr, _("syntax: %s DEVICE [-g]|[-p]\n"), argv[0]);
return 1;
@@ -85,10 +85,11 @@ int main(int argc, char **argv)
path = argv[1];
if (virIsDevMapperDevice(path)) {
- /* The 'devmap_nopartsep' option will not append the partsep of
"p"
- * onto the name unless the 'path' ends in a number
+ /* If the path ends with a number or we explicitly request it for
+ * path, then append the "p" partition separator. Otherwise, if
+ * the path ends with a letter already, then no need for a separator.
*/
- if (c_isdigit(path[strlen(path)-1]) || !devmap_nopartsep)
+ if (c_isdigit(path[strlen(path)-1]) || devmap_partsep)
partsep = "p";
else
partsep = "";
diff --git a/src/storage/storage_backend_disk.c b/src/storage/storage_backend_disk.c
index 3e0395d..eadf8a3 100644
--- a/src/storage/storage_backend_disk.c
+++ b/src/storage/storage_backend_disk.c
@@ -325,13 +325,14 @@ virStorageBackendDiskReadPartitions(virStoragePoolObjPtr pool,
pool->def->source.devices[0].path,
NULL);
- /* Check for the presence of the part_separator='no'. Pass this
+ /* Check for the presence of the part_separator='yes'. Pass this
* along to the libvirt_parthelper as option '-p'. This will cause
- * libvirt_parthelper to not append the "p" partition separator to
- * the generated device name, unless the name ends with a number.
+ * libvirt_parthelper to append the "p" partition separator to
+ * the generated device name for a source device which ends with
+ * a non-numeric value (e.g. mpatha would generate mpathap#).
*/
if (pool->def->source.devices[0].part_separator ==
- VIR_TRISTATE_BOOL_NO)
+ VIR_TRISTATE_BOOL_YES)
virCommandAddArg(cmd, "-p");
/* If a volume is passed, virStorageBackendDiskMakeVol only updates the
--
2.5.5