scan: add simple scan to find a pvid

diff --git a/lib/label/label.c b/lib/label/label.c
index 64b7ca097f757d7dedc3a1dbaf4dce77dff90b61..680630b8e730974fbda06d111be63c9c62afe12f 100644 (file)
--- a/lib/label/label.c
+++ b/lib/label/label.c
@@ -24,6 +24,8 @@
 #include "lib/activate/activate.h"
 #include "lib/label/hints.h"
 #include "lib/metadata/metadata.h"
+#include "lib/format_text/format-text.h"
+#include "lib/format_text/layout.h"
 
 #include <sys/stat.h>
 #include <fcntl.h>
@@ -919,6 +921,74 @@ static void _prepare_open_file_limit(struct cmd_context *cmd, unsigned int num_d
 #endif
 }
 
+int label_scan_for_pvid(struct cmd_context *cmd, char *pvid, struct device **dev_out)
+{
+       char buf[LABEL_SIZE] __attribute__((aligned(8)));
+       struct dm_list devs;
+       struct dev_iter *iter;
+       struct device_list *devl, *devl2;
+       struct device *dev;
+       struct pv_header *pvh;
+       int ret = 0;
+
+       dm_list_init(&devs);
+
+       dev_cache_scan();
+
+       if (!(iter = dev_iter_create(cmd->filter, 0))) {
+               log_error("Scanning failed to get devices.");
+               return 0;
+       }
+
+       log_debug_devs("Filtering devices to scan");
+
+       while ((dev = dev_iter_get(cmd, iter))) {
+               if (!(devl = zalloc(sizeof(*devl))))
+                       continue;
+               devl->dev = dev;
+               dm_list_add(&devs, &devl->list);
+       };
+       dev_iter_destroy(iter);
+
+       if (!scan_bcache) {
+               if (!_setup_bcache())
+                       goto_out;
+       }
+
+       log_debug_devs("Reading labels for pvid");
+
+       dm_list_iterate_items(devl, &devs) {
+               dev = devl->dev;
+
+               memset(buf, 0, sizeof(buf));
+
+               if (!label_scan_open(dev))
+                       continue;
+
+               if (!dev_read_bytes(dev, 512, LABEL_SIZE, buf)) {
+                       _scan_dev_close(dev);
+                       goto out;
+               }
+
+               pvh = (struct pv_header *)(buf + 32);
+
+               if (!memcmp(pvh->pv_uuid, pvid, ID_LEN)) {
+                       *dev_out = devl->dev;
+                       _scan_dev_close(dev);
+                       break;
+               }
+
+               _scan_dev_close(dev);
+       }
+       ret = 1;
+ out:
+       dm_list_iterate_items_safe(devl, devl2, &devs) {
+               dm_list_del(&devl->list);
+               free(devl);
+       }
+       return ret;
+}
+
 /*
  * Scan devices on the system to discover which are LVM devices.
  * Info about the LVM devices (PVs) is saved in lvmcache in a

diff --git a/lib/label/label.h b/lib/label/label.h
index 33a91fa6ced6db13e0391fd196bbd682c8dccc56..410890621fe548d870ddf13e0cba7888aa0d86d8 100644 (file)
--- a/lib/label/label.h
+++ b/lib/label/label.h
@@ -118,6 +118,8 @@ int label_scan_open(struct device *dev);
 int label_scan_open_excl(struct device *dev);
 int label_scan_open_rw(struct device *dev);
 
+int label_scan_for_pvid(struct cmd_context *cmd, char *pvid, struct device **dev_out);
+
 /*
  * Wrappers around bcache equivalents.
  * (these make it easier to disable bcache and revert to direct rw if needed)