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Diffstat (limited to 'fs/btrfs/qgroup.c')
-rw-r--r--fs/btrfs/qgroup.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 8928275823a1..f12dc687350c 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1185,9 +1185,24 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
struct btrfs_trans_handle *trans = NULL;
int ret = 0;
+ /*
+ * We need to have subvol_sem write locked, to prevent races between
+ * concurrent tasks trying to disable quotas, because we will unlock
+ * and relock qgroup_ioctl_lock across BTRFS_FS_QUOTA_ENABLED changes.
+ */
+ lockdep_assert_held_write(&fs_info->subvol_sem);
+
mutex_lock(&fs_info->qgroup_ioctl_lock);
if (!fs_info->quota_root)
goto out;
+
+ /*
+ * Request qgroup rescan worker to complete and wait for it. This wait
+ * must be done before transaction start for quota disable since it may
+ * deadlock with transaction by the qgroup rescan worker.
+ */
+ clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
+ btrfs_qgroup_wait_for_completion(fs_info, false);
mutex_unlock(&fs_info->qgroup_ioctl_lock);
/*
@@ -1205,14 +1220,13 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
+ set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
goto out;
}
if (!fs_info->quota_root)
goto out;
- clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
- btrfs_qgroup_wait_for_completion(fs_info, false);
spin_lock(&fs_info->qgroup_lock);
quota_root = fs_info->quota_root;
fs_info->quota_root = NULL;
@@ -3383,6 +3397,9 @@ qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
btrfs_warn(fs_info,
"qgroup rescan init failed, qgroup is not enabled");
ret = -EINVAL;
+ } else if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
+ /* Quota disable is in progress */
+ ret = -EBUSY;
}
if (ret) {