From bb452793d224b00a3700af9fdd9b0f183e1141f1 Mon Sep 17 00:00:00 2001
From: Michal Rostecki <mrostecki@opensuse.org>
Date: Thu, 8 Apr 2021 14:42:02 +0100
Subject: [PATCH 5/5] bsc1183855: btrfs: Do not disable quota on cleanup

Before this change, cleanup of the btrfs driver (occuring on each daemon
shutdown) resulted in disabling quotas. It was done with an assumption
that quotas can be enabled or disabled on a subvolume level, which is
not true - enabling or disabling quota is always done on a filesystem
level.

That was leading to disabling quota on btrfs filesystems on each daemon
shutdown.

This change fixes that behavior and removes misleading `subvol` prefix
from functions and methods which set up quota (on a filesystem level).

SUSE-Bugs: bsc#1175081 bsc#1183855
SUSE-Upstream-Commit: 1ec689c4c2ecda24ed8495451c53072bb0497871
Fixes: 401c8d176743 ("Add disk quota support for btrfs")
Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
---
 daemon/graphdriver/btrfs/btrfs.go | 50 +++++--------------------------
 1 file changed, 8 insertions(+), 42 deletions(-)

diff --git a/daemon/graphdriver/btrfs/btrfs.go b/daemon/graphdriver/btrfs/btrfs.go
index 0499489d16e6..0720bb571f2e 100644
--- a/daemon/graphdriver/btrfs/btrfs.go
+++ b/daemon/graphdriver/btrfs/btrfs.go
@@ -96,7 +96,7 @@ func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (grap
 	}
 
 	if userDiskQuota {
-		if err := driver.subvolEnableQuota(); err != nil {
+		if err := driver.enableQuota(); err != nil {
 			return nil, err
 		}
 	}
@@ -165,18 +165,10 @@ func (d *Driver) GetMetadata(id string) (map[string]string, error) {
 
 // Cleanup unmounts the home directory.
 func (d *Driver) Cleanup() error {
-	err := d.subvolDisableQuota()
-	umountErr := mount.Unmount(d.home)
-
-	// in case we have two errors, prefer the one from disableQuota()
-	if err != nil {
+	if err := mount.Unmount(d.home); err != nil {
 		return err
 	}
 
-	if umountErr != nil {
-		return umountErr
-	}
-
 	return nil
 }
 
@@ -334,7 +326,7 @@ func (d *Driver) updateQuotaStatus() {
 	d.once.Do(func() {
 		if !d.quotaEnabled {
 			// In case quotaEnabled is not set, check qgroup and update quotaEnabled as needed
-			if err := subvolQgroupStatus(d.home); err != nil {
+			if err := qgroupStatus(d.home); err != nil {
 				// quota is still not enabled
 				return
 			}
@@ -343,7 +335,7 @@ func (d *Driver) updateQuotaStatus() {
 	})
 }
 
-func (d *Driver) subvolEnableQuota() error {
+func (d *Driver) enableQuota() error {
 	d.updateQuotaStatus()
 
 	if d.quotaEnabled {
@@ -369,32 +361,6 @@ func (d *Driver) subvolEnableQuota() error {
 	return nil
 }
 
-func (d *Driver) subvolDisableQuota() error {
-	d.updateQuotaStatus()
-
-	if !d.quotaEnabled {
-		return nil
-	}
-
-	dir, err := openDir(d.home)
-	if err != nil {
-		return err
-	}
-	defer closeDir(dir)
-
-	var args C.struct_btrfs_ioctl_quota_ctl_args
-	args.cmd = C.BTRFS_QUOTA_CTL_DISABLE
-	_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(dir), C.BTRFS_IOC_QUOTA_CTL,
-		uintptr(unsafe.Pointer(&args)))
-	if errno != 0 {
-		return fmt.Errorf("Failed to disable btrfs quota for %s: %v", dir, errno.Error())
-	}
-
-	d.quotaEnabled = false
-
-	return nil
-}
-
 func (d *Driver) subvolRescanQuota() error {
 	d.updateQuotaStatus()
 
@@ -437,11 +403,11 @@ func subvolLimitQgroup(path string, size uint64) error {
 	return nil
 }
 
-// subvolQgroupStatus performs a BTRFS_IOC_TREE_SEARCH on the root path
+// qgroupStatus performs a BTRFS_IOC_TREE_SEARCH on the root path
 // with search key of BTRFS_QGROUP_STATUS_KEY.
 // In case qgroup is enabled, the retuned key type will match BTRFS_QGROUP_STATUS_KEY.
 // For more details please see https://github.com/kdave/btrfs-progs/blob/v4.9/qgroup.c#L1035
-func subvolQgroupStatus(path string) error {
+func qgroupStatus(path string) error {
 	dir, err := openDir(path)
 	if err != nil {
 		return err
@@ -608,7 +574,7 @@ func (d *Driver) setStorageSize(dir string, driver *Driver) error {
 	if d.options.minSpace > 0 && driver.options.size < d.options.minSpace {
 		return fmt.Errorf("btrfs: storage size cannot be less than %s", units.HumanSize(float64(d.options.minSpace)))
 	}
-	if err := d.subvolEnableQuota(); err != nil {
+	if err := d.enableQuota(); err != nil {
 		return err
 	}
 	return subvolLimitQgroup(dir, driver.options.size)
@@ -662,7 +628,7 @@ func (d *Driver) Get(id, mountLabel string) (containerfs.ContainerFS, error) {
 
 	if quota, err := ioutil.ReadFile(d.quotasDirID(id)); err == nil {
 		if size, err := strconv.ParseUint(string(quota), 10, 64); err == nil && size >= d.options.minSpace {
-			if err := d.subvolEnableQuota(); err != nil {
+			if err := d.enableQuota(); err != nil {
 				return nil, err
 			}
 			if err := subvolLimitQgroup(dir, size); err != nil {
-- 
2.30.2