[docker-io/epel7] discard freespace on image delete (BZ 1055645)
Lokesh Mandvekar
lsm5 at fedoraproject.org
Mon Jan 20 23:28:20 UTC 2014
commit 104c7311e86b5bba7e396b75a7e3fbdbcdf3f9e0
Author: Lokesh Mandvekar <lsm5 at redhat.com>
Date: Mon Jan 20 17:54:33 2014 -0500
discard freespace on image delete (BZ 1055645)
Signed-off-by: Lokesh Mandvekar <lsm5 at redhat.com>
devicemapper-discard-freespace.patch | 137 ++++++++++++++++++++++++++++++++++
docker-io.spec | 14 +++-
2 files changed, 148 insertions(+), 3 deletions(-)
---
diff --git a/devicemapper-discard-freespace.patch b/devicemapper-discard-freespace.patch
new file mode 100644
index 0000000..355d971
--- /dev/null
+++ b/devicemapper-discard-freespace.patch
@@ -0,0 +1,137 @@
+From 93e120e7d67313086d8bdecbcb57ea68958f91e4 Mon Sep 17 00:00:00 2001
+From: Alexander Larsson <alexl at redhat.com>
+Date: Tue, 17 Dec 2013 09:12:44 +0100
+Subject: [PATCH] Discard all data on devicemapper devices when deleting them
+
+This works around the fact that deleting a device in a thin pool
+doesn't discard the free space. Unfortunately even this is not perfect,
+as it seems discards are respected only for blocks that has never been
+shared in the thin device code. However, this has been fixed in the
+upstream kernel device-mapper tree:
+
+http://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=for-next&id=0ab1c92ff748b745c1ed7cde31bb37ad2c5f901a
+
+When this hits the kernel I belive this will fully return space
+for removed images/containers to the host FS. For now it only
+helps partially (which is better than nothing).
+
+Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl at redhat.com> (github: alexlarsson)
+---
+ graphdriver/devmapper/deviceset.go | 9 +++++++++
+ graphdriver/devmapper/devmapper.go | 24 ++++++++++++++++++++++++
+ graphdriver/devmapper/devmapper_wrapper.go | 1 +
+ graphdriver/devmapper/driver_test.go | 4 ++++
+ graphdriver/devmapper/ioctl.go | 11 +++++++++++
+ 5 files changed, 49 insertions(+)
+
+diff --git a/graphdriver/devmapper/deviceset.go b/graphdriver/devmapper/deviceset.go
+index 7308c0e..6e3caf6 100644
+--- a/graphdriver/devmapper/deviceset.go
++++ b/graphdriver/devmapper/deviceset.go
+@@ -568,6 +568,15 @@ func (devices *DeviceSet) removeDevice(hash string) error {
+ return fmt.Errorf("hash %s doesn't exists", hash)
+ }
+
++ // This is a workaround for the kernel not discarding block so
++ // on the thin pool when we remove a thinp device, so we do it
++ // manually
++ if err := devices.activateDeviceIfNeeded(hash); err == nil {
++ if err := BlockDeviceDiscard(info.DevName()); err != nil {
++ utils.Debugf("Error discarding block on device: %s (ignoring)\n", err)
++ }
++ }
++
+ devinfo, _ := getInfo(info.Name())
+ if devinfo != nil && devinfo.Exists != 0 {
+ if err := removeDevice(info.Name()); err != nil {
+diff --git a/graphdriver/devmapper/devmapper.go b/graphdriver/devmapper/devmapper.go
+index dfbdf38..d3eba78 100644
+--- a/graphdriver/devmapper/devmapper.go
++++ b/graphdriver/devmapper/devmapper.go
+@@ -7,6 +7,7 @@ import (
+ "fmt"
+ "github.com/dotcloud/docker/utils"
+ "runtime"
++ "syscall"
+ )
+
+ type DevmapperLogger interface {
+@@ -288,6 +289,29 @@ func GetBlockDeviceSize(file *osFile) (uint64, error) {
+ return uint64(size), nil
+ }
+
++func BlockDeviceDiscard(path string) error {
++ file, err := osOpenFile(path, osORdWr, 0)
++ if err != nil {
++ return err
++ }
++ defer file.Close()
++
++ size, err := GetBlockDeviceSize(file)
++ if err != nil {
++ return err
++ }
++
++ if err := ioctlBlkDiscard(file.Fd(), 0, size); err != nil {
++ return err
++ }
++
++ // Without this sometimes the remove of the device that happens after
++ // discard fails with EBUSY.
++ syscall.Sync()
++
++ return nil
++}
++
+ // This is the programmatic example of "dmsetup create"
+ func createPool(poolName string, dataFile, metadataFile *osFile) error {
+ task, err := createTask(DeviceCreate, poolName)
+diff --git a/graphdriver/devmapper/devmapper_wrapper.go b/graphdriver/devmapper/devmapper_wrapper.go
+index 80d430e..7e6dd5e 100644
+--- a/graphdriver/devmapper/devmapper_wrapper.go
++++ b/graphdriver/devmapper/devmapper_wrapper.go
+@@ -66,6 +66,7 @@ type (
+ // IOCTL consts
+ const (
+ BlkGetSize64 = C.BLKGETSIZE64
++ BlkDiscard = C.BLKDISCARD
+
+ LoopSetFd = C.LOOP_SET_FD
+ LoopCtlGetFree = C.LOOP_CTL_GET_FREE
+diff --git a/graphdriver/devmapper/driver_test.go b/graphdriver/devmapper/driver_test.go
+index b6d997b..9a2e409 100644
+--- a/graphdriver/devmapper/driver_test.go
++++ b/graphdriver/devmapper/driver_test.go
+@@ -641,6 +641,10 @@ func TestDriverRemove(t *testing.T) {
+ "DmTaskSetMessage",
+ "DmTaskCreate",
+ "DmTaskGetInfo",
++ "DmTaskSetCookie",
++ "DmTaskSetTarget",
++ "DmTaskSetAddNode",
++ "DmUdevWait",
+ "Mounted",
+ "sysUnmount",
+ )
+diff --git a/graphdriver/devmapper/ioctl.go b/graphdriver/devmapper/ioctl.go
+index 448d2d5..f9bf34f 100644
+--- a/graphdriver/devmapper/ioctl.go
++++ b/graphdriver/devmapper/ioctl.go
+@@ -58,3 +58,14 @@ func ioctlBlkGetSize64(fd uintptr) (int64, error) {
+ }
+ return size, nil
+ }
++
++func ioctlBlkDiscard(fd uintptr, offset, length uint64) error {
++ var r [2]uint64
++ r[0] = offset
++ r[1] = length
++
++ if _, _, err := sysSyscall(sysSysIoctl, fd, BlkDiscard, uintptr(unsafe.Pointer(&r[0]))); err != 0 {
++ return err
++ }
++ return nil
++}
+--
+1.8.5.1
+
diff --git a/docker-io.spec b/docker-io.spec
index b94c3a8..9e95ea0 100644
--- a/docker-io.spec
+++ b/docker-io.spec
@@ -14,11 +14,12 @@
Name: docker-io
Version: 0.7.6
-Release: 1%{?dist}
+Release: 2%{?dist}
Summary: Automates deployment of containerized applications
License: ASL 2.0
Patch0: docker-0.7-el6-docs.patch
+Patch1: devicemapper-discard-freespace.patch
URL: http://www.docker.io
# only x86_64 for now: https://github.com/dotcloud/docker/issues/136
ExclusiveArch: x86_64
@@ -55,7 +56,7 @@ Requires: tar
Requires: xz
# https://bugzilla.redhat.com/show_bug.cgi?id=1035436
# this won't be needed for rhel7+
-%if 0%{?rhel} >= 6
+%if 0%{?rhel} >= 6 && 0%{?rhel} < 7
Requires: bridge-utils
%endif
# https://bugzilla.redhat.com/show_bug.cgi?id=1034919
@@ -77,8 +78,11 @@ servers, OpenStack clusters, public instances, or combinations of the above.
%setup -q -n docker-%{version}
rm -rf vendor
%if 0%{?rhel} >= 6
-%patch0 -p1 -b docker-0.7-el6-docs.patch
+%patch0 -p1 -b docker-0.7-el6-docs
%endif
+# discard free space after deleting image
+# https://bugzilla.redhat.com/show_bug.cgi?id=1055645
+%patch1 -p1 -b devicemapper-discard-freespace
%build
mkdir _build
@@ -169,6 +173,10 @@ fi
%{_sysconfdir}/udev/rules.d/80-docker.rules
%changelog
+* Mon Jan 20 2014 Lokesh Mandvekar <lsm5 at redhat.com> - 0.7.6-2
+- bridge-utils only for rhel < 7
+- discard freespace when image is removed
+
* Thu Jan 16 2014 Lokesh Mandvekar <lsm5 at redhat.com> - 0.7.6-1
- upstream version bump v0.7.6
- built with golang >= 1.2
More information about the scm-commits
mailing list