From 77b2275dfcebce16ceea17ddf77a7f9d0a41c082 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Fri, 31 Jul 2009 11:55:38 +0100
Subject: [PATCH] New commands: swapon-*, swapoff-*, mkswap-file.

swapon-device
swapoff-device
swapon-file
swapoff-file
swapon-label
swapoff-label
swapon-uuid
swapoff-uuid
mkswap-file
---
 TODO                  |   5 --
 capitests/Makefile.am |   1 +
 daemon/swap.c         | 130 +++++++++++++++++++++++++++++++++++++++++++++++++-
 src/MAX_PROC_NR       |   2 +-
 src/generator.ml      |  96 ++++++++++++++++++++++++++++++++++++-
 5 files changed, 225 insertions(+), 9 deletions(-)

diff --git a/TODO b/TODO
index 0326ad9..28b884f 100644
--- a/TODO
+++ b/TODO
@@ -172,11 +172,6 @@ Ideas for extra commands
     pivot_root
     fts(3) / ftw(3)
 
-Swap space
-----------
-
-Allow swap space from the guest to be used.  Is it a good idea?
-
 Other initrd-* commands
 -----------------------
 
diff --git a/capitests/Makefile.am b/capitests/Makefile.am
index bb931e6..71928ec 100644
--- a/capitests/Makefile.am
+++ b/capitests/Makefile.am
@@ -35,6 +35,7 @@ TESTS_ENVIRONMENT = \
 	SKIP_TEST_NTFS_3G_PROBE=$(shell test -x ../initramfs/bin/ntfs-3g.probe || echo 1) \
 	SKIP_TEST_CHECKSUM_8=$(shell if test `find ../initramfs -name squashfs.ko | wc -l` -eq 0; then echo 1; fi) \
 	SKIP_TEST_MKSWAP_U=$(shell r=1; if test -x ../initramfs/sbin/mkswap; then if ../initramfs/sbin/mkswap --help 2>&1 | grep -sq -- -U; then r=0; fi; fi; echo $$r) \
+	SKIP_TEST_SWAPON_UUID=$$SKIP_TEST_MKSWAP_U \
 	SKIP_TEST_SCRUB_FILE=$(shell test -x ../initramfs/usr/bin/scrub || echo 1) \
 	SKIP_TEST_SCRUB_DEVICE=$(shell test -x ../initramfs/usr/bin/scrub || echo 1) \
 	$(VG)
diff --git a/daemon/swap.c b/daemon/swap.c
index faed7f6..db93e57 100644
--- a/daemon/swap.c
+++ b/daemon/swap.c
@@ -33,8 +33,6 @@ mkswap (char *device, const char *flag, const char *value)
   char *err;
   int r;
 
-  IS_DEVICE (device, -1);
-
   if (!flag)
     r = command (NULL, &err, "/sbin/mkswap", device, NULL);
   else
@@ -54,17 +52,145 @@ mkswap (char *device, const char *flag, const char *value)
 int
 do_mkswap (char *device)
 {
+  IS_DEVICE (device, -1);
+
   return mkswap (device, NULL, NULL);
 }
 
 int
 do_mkswap_L (char *label, char *device)
 {
+  IS_DEVICE (device, -1);
+
   return mkswap (device, "-L", label);
 }
 
 int
 do_mkswap_U (char *uuid, char *device)
 {
+  IS_DEVICE (device, -1);
+
   return mkswap (device, "-U", uuid);
 }
+
+int
+do_mkswap_file (char *path)
+{
+  char *buf;
+  int r;
+
+  NEED_ROOT (-1);
+  ABS_PATH (path, -1);
+
+  buf = sysroot_path (path);
+  if (!buf) {
+    reply_with_perror ("malloc");
+    return -1;
+  }
+
+  r = mkswap (buf, NULL, NULL);
+  free (buf);
+  return r;
+}
+
+static int
+swaponoff (const char *cmd, const char *flag, const char *value)
+{
+  char *err;
+  int r;
+
+  if (!flag)
+    r = command (NULL, &err, cmd, value, NULL);
+  else
+    r = command (NULL, &err, cmd, flag, value, NULL);
+
+  if (r == -1) {
+    reply_with_error ("%s: %s: %s", cmd, value, err);
+    free (err);
+    return -1;
+  }
+
+  free (err);
+
+  return 0;
+}
+
+int
+do_swapon_device (char *device)
+{
+  IS_DEVICE (device, -1);
+
+  return swaponoff ("/sbin/swapon", NULL, device);
+}
+
+int
+do_swapoff_device (char *device)
+{
+  IS_DEVICE (device, -1);
+
+  return swaponoff ("/sbin/swapoff", NULL, device);
+}
+
+int
+do_swapon_file (char *path)
+{
+  char *buf;
+  int r;
+
+  NEED_ROOT (-1);
+  ABS_PATH (path, -1);
+
+  buf = sysroot_path (path);
+  if (!buf) {
+    reply_with_perror ("malloc");
+    return -1;
+  }
+
+  r = swaponoff ("/sbin/swapon", NULL, buf);
+  free (buf);
+  return r;
+}
+
+int
+do_swapoff_file (char *path)
+{
+  char *buf;
+  int r;
+
+  NEED_ROOT (-1);
+  ABS_PATH (path, -1);
+
+  buf = sysroot_path (path);
+  if (!buf) {
+    reply_with_perror ("malloc");
+    return -1;
+  }
+
+  r = swaponoff ("/sbin/swapoff", NULL, buf);
+  free (buf);
+  return r;
+}
+
+int
+do_swapon_label (char *label)
+{
+  return swaponoff ("/sbin/swapon", "-L", label);
+}
+
+int
+do_swapoff_label (char *label)
+{
+  return swaponoff ("/sbin/swapoff", "-L", label);
+}
+
+int
+do_swapon_uuid (char *uuid)
+{
+  return swaponoff ("/sbin/swapon", "-U", uuid);
+}
+
+int
+do_swapoff_uuid (char *uuid)
+{
+  return swaponoff ("/sbin/swapoff", "-U", uuid);
+}
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index fb402ef..f84d24e 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-169
+178
diff --git a/src/generator.ml b/src/generator.ml
index e30f5eb..b0b3f06 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -2757,7 +2757,11 @@ Create a swap partition on C<device>.");
        ["mkswap_L"; "hello"; "/dev/sda1"]])],
    "create a swap partition with a label",
    "\
-Create a swap partition on C<device> with label C<label>.");
+Create a swap partition on C<device> with label C<label>.
+
+Note that you cannot attach a swap label to a block device
+(eg. C</dev/sda>), just to a partition.  This appears to be
+a limitation of the kernel or swap tools.");
 
   ("mkswap_U", (RErr, [String "uuid"; String "device"]), 132, [],
    [InitEmpty, Always, TestRun (
@@ -3201,6 +3205,96 @@ Do not confuse this with the guestfish-specific
 C<alloc> command which allocates a file in the host and
 attaches it as a device.");
 
+  ("swapon_device", (RErr, [String "device"]), 170, [],
+   [InitNone, Always, TestRun (
+      [["mkswap"; "/dev/sdb"];
+       ["swapon_device"; "/dev/sdb"];
+       ["swapoff_device"; "/dev/sdb"]])],
+   "enable swap on device",
+   "\
+This command enables the libguestfs appliance to use the
+swap device or partition named C<device>.  The increased
+memory is made available for all commands, for example
+those run using C<guestfs_command> or C<guestfs_sh>.
+
+Note that you should not swap to existing guest swap
+partitions unless you know what you are doing.  They may
+contain hibernation information, or other information that
+the guest doesn't want you to trash.  You also risk leaking
+information about the host to the guest this way.  Instead,
+attach a new host device to the guest and swap on that.");
+
+  ("swapoff_device", (RErr, [String "device"]), 171, [],
+   [], (* XXX tested by swapon_device *)
+   "disable swap on device",
+   "\
+This command disables the libguestfs appliance swap
+device or partition named C<device>.
+See C<guestfs_swapon_device>.");
+
+  ("swapon_file", (RErr, [String "file"]), 172, [],
+   [InitBasicFS, Always, TestRun (
+      [["fallocate"; "/swap"; "8388608"];
+       ["mkswap_file"; "/swap"];
+       ["swapon_file"; "/swap"];
+       ["swapoff_file"; "/swap"]])],
+   "enable swap on file",
+   "\
+This command enables swap to a file.
+See C<guestfs_swapon_device> for other notes.");
+
+  ("swapoff_file", (RErr, [String "file"]), 173, [],
+   [], (* XXX tested by swapon_file *)
+   "disable swap on file",
+   "\
+This command disables the libguestfs appliance swap on file.");
+
+  ("swapon_label", (RErr, [String "label"]), 174, [],
+   [InitEmpty, Always, TestRun (
+      [["sfdiskM"; "/dev/sdb"; ","];
+       ["mkswap_L"; "swapit"; "/dev/sdb1"];
+       ["swapon_label"; "swapit"];
+       ["swapoff_label"; "swapit"]])],
+   "enable swap on labelled swap partition",
+   "\
+This command enables swap to a labelled swap partition.
+See C<guestfs_swapon_device> for other notes.");
+
+  ("swapoff_label", (RErr, [String "label"]), 175, [],
+   [], (* XXX tested by swapon_label *)
+   "disable swap on labelled swap partition",
+   "\
+This command disables the libguestfs appliance swap on
+labelled swap partition.");
+
+  ("swapon_uuid", (RErr, [String "uuid"]), 176, [],
+   [InitEmpty, Always, TestRun (
+      [["mkswap_U"; "a3a61220-882b-4f61-89f4-cf24dcc7297d"; "/dev/sdb"];
+       ["swapon_uuid"; "a3a61220-882b-4f61-89f4-cf24dcc7297d"];
+       ["swapoff_uuid"; "a3a61220-882b-4f61-89f4-cf24dcc7297d"]])],
+   "enable swap on swap partition by UUID",
+   "\
+This command enables swap to a swap partition with the given UUID.
+See C<guestfs_swapon_device> for other notes.");
+
+  ("swapoff_uuid", (RErr, [String "uuid"]), 177, [],
+   [], (* XXX tested by swapon_uuid *)
+   "disable swap on swap partition by UUID",
+   "\
+This command disables the libguestfs appliance swap partition
+with the given UUID.");
+
+  ("mkswap_file", (RErr, [String "path"]), 178, [],
+   [InitBasicFS, Always, TestRun (
+      [["fallocate"; "/swap"; "8388608"];
+       ["mkswap_file"; "/swap"]])],
+   "create a swap file",
+   "\
+Create a swap file.
+
+This command just writes a swap file signature to an existing
+file.  To create the file itself, use something like C<guestfs_fallocate>.");
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions
-- 
1.8.3.1