rbd: add a command to delete all snapshots of an image

This makes deleting images with many snapshots easier.

Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>

7 files changed, 67 insertions, 5 deletions

diff --git a/doc/man/8/rbd.rst b/doc/man/8/rbd.rst
index 12a124401ed..fbf8e3cf638 100644
--- a/doc/man/8/rbd.rst
+++ b/doc/man/8/rbd.rst
@@ -81,7 +81,8 @@ Commands
   Resizes rbd image. The size parameter also needs to be specified.
 
 :command:`rm` [*image-name*]
-  Deletes rbd image (including all data blocks)
+  Deletes an rbd image (including all data blocks). If the image has
+  snapshots, this fails and nothing is deleted.
 
 :command:`export` [*image-name*] [*dest-path*]
   Exports image to dest path.
@@ -108,6 +109,9 @@ Commands
 :command:`snap` rm [*image-name*]
   Removes the specified snapshot.
 
+:command:`snap` purge [*image-name*]
+  Removes all snapshots from an image.
+
 :command:`map` [*image-name*]
   Maps the specified image to a block device via the rbd kernel module.
 
diff --git a/man/rbd.8 b/man/rbd.8
index 16da65aea1f..0278137d857 100644
--- a/man/rbd.8
+++ b/man/rbd.8
@@ -103,7 +103,8 @@ Will create a new rbd image. You must also specify the size via \-\-size.
 Resizes rbd image. The size parameter also needs to be specified.
 .TP
 .B \fBrm\fP [\fIimage\-name\fP]
-Deletes rbd image (including all data blocks)
+Deletes an rbd image (including all data blocks). If the image has
+snapshots, this fails and nothing is deleted.
 .TP
 .B \fBexport\fP [\fIimage\-name\fP] [\fIdest\-path\fP]
 Exports image to dest path.
@@ -130,6 +131,9 @@ array and update the data head content to the snapshotted version.
 .B \fBsnap\fP rm [\fIimage\-name\fP]
 Removes the specified snapshot.
 .TP
+.B \fBsnap\fP purge [\fIimage\-name\fP]
+Removes all snapshots from an image.
+.TP
 .B \fBmap\fP [\fIimage\-name\fP]
 Maps the specified image to a block device via the rbd kernel module.
 .TP
diff --git a/qa/workunits/rbd/copy.sh b/qa/workunits/rbd/copy.sh
index 3c6bb029abd..5d922920ad9 100755
--- a/qa/workunits/rbd/copy.sh
+++ b/qa/workunits/rbd/copy.sh
@@ -2,6 +2,7 @@
 
 TMP_FILES="/tmp/img1 /tmp/img1.new /tmp/img2 /tmp/img2.new /tmp/img3 /tmp/img3.new /tmp/img1.snap1"
 
+rbd snap purge testimg1 || true
 rbd rm testimg1 || true
 rbd rm testimg2 || true
 rbd rm testimg3 || true
diff --git a/qa/workunits/rbd/kernel.sh b/qa/workunits/rbd/kernel.sh
index c0eced27193..bf8452aa578 100755
--- a/qa/workunits/rbd/kernel.sh
+++ b/qa/workunits/rbd/kernel.sh
@@ -20,6 +20,7 @@ function clean_up {
 	rbd unmap /dev/rbd/rbd/testimg1 || true
 	rbd unmap /dev/rbd/rbd/testimg1@snap1 || true
 	sudo chown root /sys/bus/rbd/add /sys/bus/rbd/remove
+	rbd snap purge testimg1 || true
 	rbd rm testimg1 || true
 	sudo rm -f $TMP_FILES
 }
diff --git a/src/rbd.cc b/src/rbd.cc
index 216d0f9f2c7..3f86de6357f 100644
--- a/src/rbd.cc
+++ b/src/rbd.cc
@@ -78,6 +78,7 @@ void usage()
        << "  snap create <--snap=name> [image-name]    create a snapshot\n"
        << "  snap rollback <--snap=name> [image-name]  rollback image head to snapshot\n"
        << "  snap rm <--snap=name> [image-name]        deletes a snapshot\n"
+       << "  snap purge [image-name]                   deletes all snapshots\n"
        << "  watch [image-name]                        watch events on image\n"
        << "  map [image-name]                          map the image to a block device\n"
        << "                                            using the kernel\n"
@@ -259,6 +260,25 @@ static int do_rollback_snap(librbd::Image& image, const char *snapname)
   return 0;
 }
 
+static int do_purge_snaps(librbd::Image& image)
+{
+  MyProgressContext pc("Removing all snapshots");
+  std::vector<librbd::snap_info_t> snaps;
+  int r = image.snap_list(snaps);
+  if (r < 0) {
+    pc.fail();
+    return r;
+  }
+
+  for (size_t i = 0; i < snaps.size(); ++i) {
+    image.snap_remove(snaps[i].name.c_str());
+    pc.update_progress(i + 1, snaps.size());
+  }
+
+  pc.finish();
+  return 0;
+}
+
 struct ExportContext {
   int fd;
   MyProgressContext pc;
@@ -815,6 +835,7 @@ enum {
   OPT_SNAP_ROLLBACK,
   OPT_SNAP_REMOVE,
   OPT_SNAP_LIST,
+  OPT_SNAP_PURGE,
   OPT_WATCH,
   OPT_MAP,
   OPT_UNMAP,
@@ -866,6 +887,8 @@ static int get_cmd(const char *cmd, bool snapcmd)
     if (strcmp(cmd, "ls") == 0||
         strcmp(cmd, "list") == 0)
       return OPT_SNAP_LIST;
+    if (strcmp(cmd, "purge") == 0)
+      return OPT_SNAP_PURGE;
   }
 
   return OPT_NO_CMD;
@@ -979,6 +1002,7 @@ int main(int argc, const char **argv)
       case OPT_SNAP_ROLLBACK:
       case OPT_SNAP_REMOVE:
       case OPT_SNAP_LIST:
+      case OPT_SNAP_PURGE:
       case OPT_WATCH:
       case OPT_MAP:
 	set_conf_param(v, &imgname, NULL);
@@ -1083,8 +1107,8 @@ int main(int argc, const char **argv)
   if (imgname && talk_to_cluster &&
       (opt_cmd == OPT_RESIZE || opt_cmd == OPT_INFO || opt_cmd == OPT_SNAP_LIST ||
        opt_cmd == OPT_SNAP_CREATE || opt_cmd == OPT_SNAP_ROLLBACK ||
-       opt_cmd == OPT_SNAP_REMOVE || opt_cmd == OPT_EXPORT || opt_cmd == OPT_WATCH ||
-       opt_cmd == OPT_COPY)) {
+       opt_cmd == OPT_SNAP_REMOVE || opt_cmd == OPT_SNAP_PURGE ||
+       opt_cmd == OPT_EXPORT || opt_cmd == OPT_WATCH || opt_cmd == OPT_COPY)) {
     r = rbd.open(io_ctx, image, imgname);
     if (r < 0) {
       cerr << "error opening image " << imgname << ": " << cpp_strerror(-r) << std::endl;
@@ -1161,7 +1185,13 @@ int main(int argc, const char **argv)
   case OPT_RM:
     r = do_delete(rbd, io_ctx, imgname);
     if (r < 0) {
-      cerr << "delete error: " << cpp_strerror(-r) << std::endl;
+      if (r == -EBUSY) {
+	cerr << "delete error: image has snapshots - these must be deleted"
+	     << " with 'rbd snap purge' before the image can be removed."
+	     << std::endl;
+      } else {
+	cerr << "delete error: " << cpp_strerror(-r) << std::endl;
+      }
       exit(1);
     }
     break;
@@ -1222,6 +1252,18 @@ int main(int argc, const char **argv)
     }
     break;
 
+  case OPT_SNAP_PURGE:
+    if (!imgname) {
+      usage();
+      exit(1);
+    }
+    r = do_purge_snaps(image);
+    if (r < 0) {
+      cerr << "removing snaps failed: " << cpp_strerror(-r) << std::endl;
+      exit(1);
+    }
+    break;
+
   case OPT_EXPORT:
     if (!path) {
       cerr << "pathname should be specified" << std::endl;
diff --git a/src/test/cli/rbd/help.t b/src/test/cli/rbd/help.t
index e9aafff4e23..3c804457b97 100644
--- a/src/test/cli/rbd/help.t
+++ b/src/test/cli/rbd/help.t
@@ -16,6 +16,7 @@
     snap create <--snap=name> [image-name]    create a snapshot
     snap rollback <--snap=name> [image-name]  rollback image head to snapshot
     snap rm <--snap=name> [image-name]        deletes a snapshot
+    snap purge [image-name]                   deletes all snapshots
     watch [image-name]                        watch events on image
     map [image-name]                          map the image to a block device
                                               using the kernel
diff --git a/src/test/cli/rbd/invalid-snap-usage.t b/src/test/cli/rbd/invalid-snap-usage.t
index 44037e4b13c..771e4c2fd2b 100644
--- a/src/test/cli/rbd/invalid-snap-usage.t
+++ b/src/test/cli/rbd/invalid-snap-usage.t
@@ -17,6 +17,7 @@
     snap create <--snap=name> [image-name]    create a snapshot
     snap rollback <--snap=name> [image-name]  rollback image head to snapshot
     snap rm <--snap=name> [image-name]        deletes a snapshot
+    snap purge [image-name]                   deletes all snapshots
     watch [image-name]                        watch events on image
     map [image-name]                          map the image to a block device
                                               using the kernel
@@ -59,6 +60,7 @@
     snap create <--snap=name> [image-name]    create a snapshot
     snap rollback <--snap=name> [image-name]  rollback image head to snapshot
     snap rm <--snap=name> [image-name]        deletes a snapshot
+    snap purge [image-name]                   deletes all snapshots
     watch [image-name]                        watch events on image
     map [image-name]                          map the image to a block device
                                               using the kernel
@@ -101,6 +103,7 @@
     snap create <--snap=name> [image-name]    create a snapshot
     snap rollback <--snap=name> [image-name]  rollback image head to snapshot
     snap rm <--snap=name> [image-name]        deletes a snapshot
+    snap purge [image-name]                   deletes all snapshots
     watch [image-name]                        watch events on image
     map [image-name]                          map the image to a block device
                                               using the kernel
@@ -143,6 +146,7 @@
     snap create <--snap=name> [image-name]    create a snapshot
     snap rollback <--snap=name> [image-name]  rollback image head to snapshot
     snap rm <--snap=name> [image-name]        deletes a snapshot
+    snap purge [image-name]                   deletes all snapshots
     watch [image-name]                        watch events on image
     map [image-name]                          map the image to a block device
                                               using the kernel
@@ -185,6 +189,7 @@
     snap create <--snap=name> [image-name]    create a snapshot
     snap rollback <--snap=name> [image-name]  rollback image head to snapshot
     snap rm <--snap=name> [image-name]        deletes a snapshot
+    snap purge [image-name]                   deletes all snapshots
     watch [image-name]                        watch events on image
     map [image-name]                          map the image to a block device
                                               using the kernel
@@ -227,6 +232,7 @@
     snap create <--snap=name> [image-name]    create a snapshot
     snap rollback <--snap=name> [image-name]  rollback image head to snapshot
     snap rm <--snap=name> [image-name]        deletes a snapshot
+    snap purge [image-name]                   deletes all snapshots
     watch [image-name]                        watch events on image
     map [image-name]                          map the image to a block device
                                               using the kernel
@@ -269,6 +275,7 @@
     snap create <--snap=name> [image-name]    create a snapshot
     snap rollback <--snap=name> [image-name]  rollback image head to snapshot
     snap rm <--snap=name> [image-name]        deletes a snapshot
+    snap purge [image-name]                   deletes all snapshots
     watch [image-name]                        watch events on image
     map [image-name]                          map the image to a block device
                                               using the kernel
@@ -311,6 +318,7 @@
     snap create <--snap=name> [image-name]    create a snapshot
     snap rollback <--snap=name> [image-name]  rollback image head to snapshot
     snap rm <--snap=name> [image-name]        deletes a snapshot
+    snap purge [image-name]                   deletes all snapshots
     watch [image-name]                        watch events on image
     map [image-name]                          map the image to a block device
                                               using the kernel
@@ -353,6 +361,7 @@
     snap create <--snap=name> [image-name]    create a snapshot
     snap rollback <--snap=name> [image-name]  rollback image head to snapshot
     snap rm <--snap=name> [image-name]        deletes a snapshot
+    snap purge [image-name]                   deletes all snapshots
     watch [image-name]                        watch events on image
     map [image-name]                          map the image to a block device
                                               using the kernel