rbdtool: add --info, --resize commands

diff --git a/src/rbdtool.cc b/src/rbdtool.cc
index d6b24ba12203842273270bb120b1d988ef8bab1f..b66ee162baa6b642695473270410db25a355da90 100644 (file)
--- a/src/rbdtool.cc
+++ b/src/rbdtool.cc
@@ -28,10 +28,21 @@ using namespace librados;
 
 #include "include/rbd_types.h"
 
+Rados rados;
+pool_t pool;
 
 void usage()
 {
-  cout << " usage: [--list] [--create <image name> --size <size in MB>] [--delete <img name>] [-p|--pool=<name>]" << std::endl;
+  cout << "usage: rbdtool [-n <auth user>] [-p|--pool <name>] <cmd>\n"
+       << "where 'pool' is a rados pool name (default is 'rbd') and 'cmd' is one of:\n"
+       << "\t--list    list rbd images\n"
+       << "\t--info    show information about image size, striping, etc.\n"
+       << "\t--create <image name> --size <size in MB>\n"
+       << "\t          create an image\n"
+       << "\t--resize <image name> --size <new size in MB>\n"
+       << "\t          resize (expand or contract) image\n"
+       << "\t--delete <image name>\n"
+       << "\t          delete an image" << std::endl;
   exit(1);
 }
 
@@ -65,6 +76,25 @@ void print_header(char *imgname, rbd_obj_header_ondisk *header)
        << std::endl;
 }
 
+void trim_image(const char *imgname, rbd_obj_header_ondisk *header, __u64 newsize)
+{
+  __u64 size = header->image_size;
+  __u64 numseg = size >> header->obj_order;
+  __u64 start = newsize >> header->obj_order;
+
+  cout << "trimming device data from " << numseg << " to " << start << " objects..." << std::endl;
+  for (__u64 i=start; i<numseg; i++) {
+    char o[RBD_MAX_SEG_NAME_SIZE];
+    sprintf(o, "%s.%012llx", imgname, (unsigned long long)i);
+    string oid = o;
+    rados.remove(pool, oid);
+    if ((i & 127) == 0) {
+      cout << "\r\t" << i << "/" << numseg;
+      cout.flush();
+    }
+  }
+}
+
 int main(int argc, const char **argv) 
 {
   vector<const char*> args;
@@ -73,19 +103,12 @@ int main(int argc, const char **argv)
   env_to_vec(args);
   common_init(args, "rbdtool", false, true);
 
-  bool opt_create = false, opt_delete = false, opt_list = false;
-  char *poolname;
+  bool opt_create = false, opt_delete = false, opt_list = false, opt_info = false, opt_resize = false;
+  char *poolname = (char *)"rbd";
   __u64 size = 0;
   int order = 0;
   char *imgname;
 
-
-  Rados rados;
-  if (rados.initialize(argc, argv) < 0) {
-     cerr << "couldn't initialize rados!" << std::endl;
-     exit(1);
-  }
-
   FOR_EACH_ARG(args) {
     if (CONF_ARG_EQ("list", '\0')) {
       CONF_SAFE_SET_ARG_VAL(&opt_list, OPT_BOOL);
@@ -95,27 +118,38 @@ int main(int argc, const char **argv)
     } else if (CONF_ARG_EQ("delete", '\0')) {
       CONF_SAFE_SET_ARG_VAL(&imgname, OPT_STR);
       opt_delete = true;
+    } else if (CONF_ARG_EQ("resize", '\0')) {
+      CONF_SAFE_SET_ARG_VAL(&imgname, OPT_STR);
+      opt_resize = true;
+    } else if (CONF_ARG_EQ("info", 'i')) {
+      CONF_SAFE_SET_ARG_VAL(&imgname, OPT_STR);
+      opt_info = true;
     } else if (CONF_ARG_EQ("pool", 'p')) {
       CONF_SAFE_SET_ARG_VAL(&poolname, OPT_STR);
     } else if (CONF_ARG_EQ("object", 'n')) {
       CONF_SAFE_SET_ARG_VAL(&imgname, OPT_STR);
     } else if (CONF_ARG_EQ("size", 's')) {
       CONF_SAFE_SET_ARG_VAL(&size, OPT_LONGLONG);
+      size <<= 20; // MB -> bytes
     } else if (CONF_ARG_EQ("order", '\0')) {
       CONF_SAFE_SET_ARG_VAL(&order, OPT_INT);
     } else 
       usage();
   }
 
-  if (!opt_create && !opt_delete && !opt_list)
+  if (!opt_create && !opt_delete && !opt_list && !opt_info && !opt_resize)
     usage();
 
+
+  if (rados.initialize(argc, argv) < 0) {
+     cerr << "couldn't initialize rados!" << std::endl;
+     exit(1);
+  }
+
   string md_oid = imgname;
   md_oid += RBD_SUFFIX;
   string dir_oid = RBD_DIRECTORY;
 
-  pool_t pool;
-
   int r = rados.open_pool(poolname, &pool);
   if (r < 0) {
     cerr << "error opening pool (err=" << r << ")" << std::endl;
@@ -137,7 +171,7 @@ int main(int argc, const char **argv)
     for (map<nstring,bufferlist>::iterator q = m.begin(); q != m.end(); q++)
       cout << q->first << std::endl;
   }
-  if (opt_create) {
+  else if (opt_create) {
     if (!size) {
       cerr << "must specify size in MB to create an rbd image" << std::endl;
       usage();
@@ -148,7 +182,6 @@ int main(int argc, const char **argv)
       usage();
       exit(1);
     }
-    size <<= 20; // MB -> bytes
 
     // make sure it doesn't already exist
     r = rados.stat(pool, md_oid, NULL, NULL);
@@ -185,46 +218,72 @@ int main(int argc, const char **argv)
     }
     cout << "done." << std::endl;
   }
-  if (opt_delete) {
+  else if (opt_info || opt_delete || opt_resize) {
+    // read header
     struct rbd_obj_header_ondisk header;
     bufferlist bl;
     r = rados.read(pool, md_oid, 0, bl, sizeof(header));
     if (r < 0) {
       cerr << "error reading header " << md_oid << ": " << strerror(-r) << std::endl;
-      exit(1);
     } else {
       bufferlist::iterator p = bl.begin();
       p.copy(sizeof(header), (char *)&header);
-      __u64 size = header.image_size;
-      __u64 numseg = size >> header.obj_order;
-      print_header(imgname, &header);
+    }
+
+    if (opt_delete) {
+      if (r >= 0) {
+       print_header(imgname, &header);
+       trim_image(imgname, &header, 0);
+       cout << "\rremoving header..." << std::endl;
+       rados.remove(pool, md_oid);
+      }
+       
+      cout << "removing rbd image to directory..." << std::endl;
+      bufferlist cmdbl;
+      __u8 c = CEPH_OSD_TMAP_RM;
+      ::encode(c, cmdbl);
+      ::encode(imgname, cmdbl);
+      r = rados.tmap_update(pool, dir_oid, cmdbl);
+      if (r < 0) {
+       cerr << "error removing img from directory: " << strerror(-r)<< std::endl;
+       exit(1);
+      }
+    } else {
+      if (r < 0)
+       exit(1);
       
-      cout << "removing data..." << std::endl;
-      for (__u64 i=0; i<numseg; i++) {
-       char o[RBD_MAX_SEG_NAME_SIZE];
-       sprintf(o, "%s.%012llx", imgname, (unsigned long long)i);
-       string oid = o;
-       rados.remove(pool, oid);
-       if ((i & 127) == 0) {
-         cout << "\r\t" << i << "/" << numseg;
-         cout.flush();
-       }
+      if (opt_info) {
+       print_header(imgname, &header);
       }
-      cout << "\rremoving header..." << std::endl;
-      rados.remove(pool, md_oid);
-    }
 
-    cout << "removing rbd image to directory..." << std::endl;
-    bufferlist cmdbl;
-    __u8 c = CEPH_OSD_TMAP_RM;
-    ::encode(c, cmdbl);
-    ::encode(imgname, cmdbl);
-    r = rados.tmap_update(pool, dir_oid, cmdbl);
-    if (r < 0) {
-      cerr << "error removing img from directory: " << strerror(-r)<< std::endl;
-      exit(1);
-    }
+      if (opt_resize) {
+       // trim
+       if (size == header.image_size) {
+         cout << "no change in size (" << size << " -> " << header.image_size << ")" << std::endl;
+         print_header(imgname, &header);
+       } else {
+         if (size > header.image_size) {
+           cout << "expanding image " << size << " -> " << header.image_size << " objects" << std::endl;
+           header.image_size = size;
+         } else {
+           cout << "shrinking image " << size << " -> " << header.image_size << " objects" << std::endl;
+           trim_image(imgname, &header, size);
+           header.image_size = size;
+         }
+         print_header(imgname, &header);
 
+         // rewrite header
+         bufferlist bl;
+         bl.append((const char *)&header, sizeof(header));
+         r = rados.write(pool, md_oid, 0, bl, bl.length());
+         if (r < 0) {
+           cerr << "error writing header: " << strerror(-r) << std::endl;
+           exit(1);
+         }
+       }
+      }
+    }
+      
     cout << "done." << std::endl;
   }