[libvirt] [PATCH v3] Improve SCSI volume key generation
The SCSI volumes get a better 'key' field based on the fully
qualified volume path. All SCSI volumes have a unique serial
available in hardware which can be obtained by sending a
suitable SCSI command. Call out to udev's 'scsi_id' command
to fetch this value
In v3:
- Use virCommandSetOutputBuffer/virCommandRun instead
of VIR_FDOPEN
- Skip serial if it matches empty string
* src/storage/storage_backend_scsi.c: Improve volume key
field value stability and uniqueness
---
src/storage/storage_backend_scsi.c | 45 ++++++++++++++++++++++++++++++++---
1 files changed, 41 insertions(+), 4 deletions(-)
diff --git a/src/storage/storage_backend_scsi.c b/src/storage/storage_backend_scsi.c
index d880d65..da34547 100644
--- a/src/storage/storage_backend_scsi.c
+++ b/src/storage/storage_backend_scsi.c
@@ -33,6 +33,7 @@
#include "memory.h"
#include "logging.h"
#include "files.h"
+#include "command.h"
#define VIR_FROM_THIS VIR_FROM_STORAGE
@@ -160,6 +161,45 @@ cleanup:
return ret;
}
+
+static char *
+virStorageBackendSCSISerial(const char *dev)
+{
+ char *serial = NULL;
+#ifdef HAVE_UDEV
+ virCommandPtr cmd = virCommandNewArgList(
+ "/lib/udev/scsi_id",
+ "--replace-whitespace",
+ "--whitelisted",
+ "--device", dev,
+ NULL
+ );
+
+ /* Run the program and capture its output */
+ virCommandSetOutputBuffer(cmd, &serial);
+ if (virCommandRun(cmd, NULL) < 0)
+ goto cleanup;
+#endif
+
+ if (serial && STRNEQ(serial, "")) {
+ char *nl = strchr(serial, '\n');
+ if (nl)
+ *nl = '\0';
+ } else {
+ VIR_FREE(serial);
+ if (!(serial = strdup(dev)))
+ virReportOOMError();
+ }
+
+#ifdef HAVE_UDEV
+cleanup:
+ virCommandFree(cmd);
+#endif
+
+ return serial;
+}
+
+
static int
virStorageBackendSCSINewLun(virStoragePoolObjPtr pool,
uint32_t host ATTRIBUTE_UNUSED,
@@ -233,10 +273,7 @@ virStorageBackendSCSINewLun(virStoragePoolObjPtr pool,
goto free_vol;
}
- /* XXX should use logical unit's UUID instead */
- vol->key = strdup(vol->target.path);
- if (vol->key == NULL) {
- virReportOOMError();
+ if (!(vol->key = virStorageBackendSCSISerial(vol->target.path))) {
retval = -1;
goto free_vol;
}
--
1.7.4