[lxc-devel] [lxd/master] Support resizing storage volumes using btrfs

[albertodonato on Github]

A non-text attachment was scrubbed...
Name: not available
Type: text/x-mailbox
Size: 301 bytes
Desc: not available
URL: <http://lists.linuxcontainers.org/pipermail/lxc-devel/attachments/20170926/ea5fb1f9/attachment.bin>
-------------- next part --------------
From 1f5d1ed6d2824a14ec0116dd20eeaf33bc86f464 Mon Sep 17 00:00:00 2001
From: Alberto Donato <alberto.donato at canonical.com>
Date: Tue, 26 Sep 2017 11:33:14 -0400
Subject: [PATCH 1/2] storage/utils: support resizing btrfs-based volumes

Signed-off-by: Alberto Donato <alberto.donato at canonical.com>
---
 lxd/storage_ceph_utils.go |  2 +-
 lxd/storage_lvm_utils.go  |  2 +-
 lxd/storage_utils.go      | 17 +++++++++++------
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/lxd/storage_ceph_utils.go b/lxd/storage_ceph_utils.go
index a6510e848..142dcabc4 100644
--- a/lxd/storage_ceph_utils.go
+++ b/lxd/storage_ceph_utils.go
@@ -1556,7 +1556,7 @@ func (s *storageCeph) rbdShrink(path string, size int64, fsType string,
 			`less than 1MB`)
 	}
 
-	cleanupFunc, err := shrinkVolumeFilesystem(s, volumeType, fsType, path, size, data)
+	cleanupFunc, err := shrinkVolumeFilesystem(s, volumeType, fsType, path, fsMntPoint, size, data)
 	if cleanupFunc != nil {
 		defer cleanupFunc()
 	}
diff --git a/lxd/storage_lvm_utils.go b/lxd/storage_lvm_utils.go
index 62e61d7c6..0b53eb712 100644
--- a/lxd/storage_lvm_utils.go
+++ b/lxd/storage_lvm_utils.go
@@ -70,7 +70,7 @@ func (s *storageLvm) lvReduce(lvPath string, lvSize int64, fsType string, fsMntP
 		return fmt.Errorf(`The size of the storage volume would be ` +
 			`less than 1MB`)
 	}
-	cleanupFunc, err := shrinkVolumeFilesystem(s, volumeType, fsType, lvPath, lvSize, data)
+	cleanupFunc, err := shrinkVolumeFilesystem(s, volumeType, fsType, lvPath, fsMntPoint, lvSize, data)
 	if cleanupFunc != nil {
 		defer cleanupFunc()
 	}
diff --git a/lxd/storage_utils.go b/lxd/storage_utils.go
index 81171a0fd..c9b438eaf 100644
--- a/lxd/storage_utils.go
+++ b/lxd/storage_utils.go
@@ -236,6 +236,8 @@ func growFileSystem(fsType string, devPath string, mntpoint string) error {
 		msg, err = shared.TryRunCommand("resize2fs", mntpoint)
 	case "xfs":
 		msg, err = shared.TryRunCommand("xfs_growfs", devPath)
+	case "btrfs":
+		msg, err = shared.TryRunCommand("btrfs", "filesystem", "resize", "max", mntpoint)
 	default:
 		return fmt.Errorf(`Growing not supported for filesystem type "%s"`, fsType)
 	}
@@ -250,9 +252,10 @@ func growFileSystem(fsType string, devPath string, mntpoint string) error {
 	return nil
 }
 
-func shrinkFileSystem(fsType string, devPath string, byteSize int64) error {
+func shrinkFileSystem(fsType string, devPath string, mntpoint string, byteSize int64) error {
 	var msg string
 	var err error
+	strSize := fmt.Sprintf("%dK", byteSize/1024)
 	switch fsType {
 	case "": // if not specified, default to ext4
 		fallthrough
@@ -261,9 +264,9 @@ func shrinkFileSystem(fsType string, devPath string, byteSize int64) error {
 		if err != nil {
 			return err
 		}
-		kbSize := byteSize / 1024
-		msg, err = shared.TryRunCommand("resize2fs", devPath, fmt.Sprintf("%dK", kbSize))
-
+		msg, err = shared.TryRunCommand("resize2fs", devPath, strSize)
+	case "btrfs":
+		msg, err = shared.TryRunCommand("btrfs", "filesystem", "resize", strSize, mntpoint)
 	default:
 		return fmt.Errorf(`Shrinking not supported for filesystem type "%s"`, fsType)
 	}
@@ -276,12 +279,14 @@ func shrinkFileSystem(fsType string, devPath string, byteSize int64) error {
 	return nil
 }
 
-func shrinkVolumeFilesystem(s storage, volumeType int, fsType string, devPath string, byteSize int64, data interface{}) (func() (bool, error), error) {
+func shrinkVolumeFilesystem(s storage, volumeType int, fsType string, devPath string, mntpoint string, byteSize int64, data interface{}) (func() (bool, error), error) {
 	var cleanupFunc func() (bool, error)
 	switch fsType {
 	case "xfs":
 		logger.Errorf("xfs filesystems cannot be shrunk: dump, mkfs, and restore are required")
 		return nil, fmt.Errorf("xfs filesystems cannot be shrunk: dump, mkfs, and restore are required")
+	case "btrfs":
+		fallthrough
 	case "": // if not specified, default to ext4
 		fallthrough
 	case "ext4":
@@ -311,6 +316,6 @@ func shrinkVolumeFilesystem(s storage, volumeType int, fsType string, devPath st
 		return nil, fmt.Errorf(`Shrinking not supported for filesystem type "%s"`, fsType)
 	}
 
-	err := shrinkFileSystem(fsType, devPath, byteSize)
+	err := shrinkFileSystem(fsType, devPath, mntpoint, byteSize)
 	return cleanupFunc, err
 }

From 3bf73e8bdcc98ccaff4d97f60636faa896a1b993 Mon Sep 17 00:00:00 2001
From: Alberto Donato <alberto.donato at canonical.com>
Date: Tue, 26 Sep 2017 15:01:47 -0400
Subject: [PATCH 2/2] add tests for btrfs resize

Signed-off-by: Alberto Donato <alberto.donato at canonical.com>
---
 test/suites/storage.sh | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/test/suites/storage.sh b/test/suites/storage.sh
index e4561dbac..5cccd94cb 100644
--- a/test/suites/storage.sh
+++ b/test/suites/storage.sh
@@ -30,6 +30,19 @@ test_storage() {
   lxc storage volume delete "$storage_pool" "$storage_volume"
 
   lxc storage delete "$storage_pool"
+
+  # Test btrfs resize
+  # shellcheck disable=2039
+  local btrfs_storage_pool btrfs_storage_volume
+  btrfs_storage_pool="lxdtest-$(basename "${LXD_DIR}")-pool-btrfs"
+  btrfs_storage_volume="${storage_pool}-vol"
+  lxc storage create "$btrfs_storage_pool" "$lxd_backend" volume.block.filesystem=btrfs
+  lxc storage volume create "$btrfs_storage_pool" "$btrfs_storage_volume"
+  if [ "$lxd_backend" != "dir" ] && [ "$lxd_backend" != "ceph" ]; then
+    lxc storage volume set "$btrfs_storage_pool" "$btrfs_storage_volume" size 200MB
+    lxc storage volume unset "$btrfs_storage_pool" "$btrfs_storage_volume" size 150MB
+  fi
+  
   (
     set -e
     # shellcheck disable=2030