On 1/18/19 3:42 PM, John Ferlan wrote:
The vHBA/NPIV LUNs created via the udev processing of the
VPORT_CREATE command end up using the same serial value
as seen/generated by the /lib/udev/scsi_id as returned
during virStorageFileGetSCSIKey. Therefore, in order to
generate a unique enough key to be used when adding the
LUN as a volume during virStoragePoolObjAddVol a more
unique key needs to be generated for an NPIV volume.
The problem is illustrated by the following example, where
scsi_host5 is a vHBA used with the following LUNs:
$ lsscsi -tg
...
[5:0:4:0] disk fc:0x5006016844602198,0x101f00 /dev/sdh /dev/sg23
[5:0:5:0] disk fc:0x5006016044602198,0x102000 /dev/sdi /dev/sg24
...
Calling virStorageFileGetSCSIKey would return:
/lib/udev/scsi_id --device /dev/sdh --whitelisted --replace-whitespace /dev/sdh
350060160c460219850060160c4602198
/lib/udev/scsi_id --device /dev/sdh --whitelisted --replace-whitespace /dev/sdi
350060160c460219850060160c4602198
Note that althrough /dev/sdh and /dev/sdi are separate LUNs, they
end up with the same serial number used for the vol->key value.
When virStoragePoolFCRefreshThread calls virStoragePoolObjAddVol
the second LUN fails to be added with the following message
getting logged:
virHashAddOrUpdateEntry:341 : internal error: Duplicate key
To resolve this, virStorageFileGetNPIVKey will use a similar call
sequence as virStorageFileGetSCSIKey, except that it will add the
"--export" option to the call. This results in more detailed output
which needs to be parsed in order to formulate a unique enough key
to be used. In order to be unique enough, the returned value will
concatenate the target port as returned in the "ID_TARGET_PORT"
field from the command to the "ID_SERIAL" value.
Signed-off-by: John Ferlan <jferlan@xxxxxxxxxx>
---
src/libvirt_private.syms | 1 +
src/util/virstoragefile.c | 80 +++++++++++++++++++++++++++++++++++++++
src/util/virstoragefile.h | 2 +
3 files changed, 83 insertions(+)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index c3d6306809..bdc2877a9f 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2861,6 +2861,7 @@ virStorageFileGetMetadata;
virStorageFileGetMetadataFromBuf;
virStorageFileGetMetadataFromFD;
virStorageFileGetMetadataInternal;
+virStorageFileGetNPIVKey;
virStorageFileGetRelativeBackingPath;
virStorageFileGetSCSIKey;
virStorageFileGetUniqueIdentifier;
diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index 2511511d14..759d0625b6 100644
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -1490,6 +1490,86 @@ int virStorageFileGetSCSIKey(const char *path,
#endif
+#ifdef WITH_UDEV
+/* virStorageFileGetNPIVKey
+ * @path: Path to the NPIV device
+ * @key: Unique key to be returned
+ *
+ * Using a udev specific function, query the @path to get and return a
+ * unique @key for the caller to use. Unlike the GetSCSIKey method, an
+ * NPIV LUN is uniquely identified by it's ID_TARGET_PORT value.
+ *
+ * Returns:
+ * 0 On success, with the @key filled in or @key=NULL if the
+ * returned output string didn't have the data we need to
+ * formulate a unique key value
+ * -1 When WITH_UDEV is undefined and a system error is reported
+ * -2 When WITH_UDEV is defined, but calling virCommandRun fails
+ */
+int
+virStorageFileGetNPIVKey(const char *path,
+ char **key)
+{
+ int status;
+ VIR_AUTOFREE(char *) outbuf = NULL;
+ const char *serial;
+ const char *port;
+ virCommandPtr cmd = virCommandNewArgList("/lib/udev/scsi_id",
+ "--replace-whitespace",
+ "--whitelisted",
+ "--export",
+ "--device", path,
+ NULL
+ );
+ int ret = -2;
+
+ *key = NULL;
+
+ /* Run the program and capture its output */
+ virCommandSetOutputBuffer(cmd, &outbuf);
+ if (virCommandRun(cmd, &status) < 0)
+ goto cleanup;
+
+ /* Explicitly check status == 0, rather than passing NULL
+ * to virCommandRun because we don't want to raise an actual
+ * error in this scenario, just return a NULL key.
+ */
+ if (status == 0 && *outbuf &&
+ (serial = strstr(outbuf, "ID_SERIAL=")) &&
+ (port = strstr(outbuf, "ID_TARGET_PORT="))) {
+ char *serial_eq = strchr(serial, '=');
+ char *serial_nl = strchr(serial, '\n');
+ char *port_eq = strchr(port, '=');
+ char *port_nl = strchr(port, '\n');
+
+ if (serial_eq)
+ serial = serial_eq + 1;
+ if (serial_nl)
+ *serial_nl = '\0';
+ if (port_eq)
+ port = port_eq + 1;
+ if (port_nl)
+ *port_nl = '\0';
This looks cleaner IMO:
# define ID_SERIAL "ID_SERIAL="
# define ID_TARGET_PORT "ID_TARGET_PORT="
and then the if() body:
char *tmp;
serial += strlen(ID_SERIAL);
port += strlen(ID_TARGET_PORT);
if ((tmp = strchr(serial, '\n')))
*tmp = '\0';
if ((tmp = strchr(port, '\n')))
*tmp = '\0';
followed by virAsprintf() you already have there.
But I don't care that much.
Michal
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