Merge tag 'v6.2' into iommufd.git for-next

Resolve conflicts from the signature change in iommu_map:

 - drivers/infiniband/hw/usnic/usnic_uiom.c
   Switch iommu_map_atomic() to iommu_map(.., GFP_ATOMIC)

 - drivers/vfio/vfio_iommu_type1.c
   Following indenting change for GFP_KERNEL

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 29 insertions, 10 deletions

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index d275bf24b250..af97413abcf4 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2765,9 +2765,19 @@ int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
 
 			/*
 			 * Old roots should be searched when inserting qgroup
-			 * extent record
+			 * extent record.
+			 *
+			 * But for INCONSISTENT (NO_ACCOUNTING) -> rescan case,
+			 * we may have some record inserted during
+			 * NO_ACCOUNTING (thus no old_roots populated), but
+			 * later we start rescan, which clears NO_ACCOUNTING,
+			 * leaving some inserted records without old_roots
+			 * populated.
+			 *
+			 * Those cases are rare and should not cause too much
+			 * time spent during commit_transaction().
 			 */
-			if (WARN_ON(!record->old_roots)) {
+			if (!record->old_roots) {
 				/* Search commit root to find old_roots */
 				ret = btrfs_find_all_roots(&ctx, false);
 				if (ret < 0)
@@ -3357,6 +3367,7 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
 	int err = -ENOMEM;
 	int ret = 0;
 	bool stopped = false;
+	bool did_leaf_rescans = false;
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -3377,6 +3388,7 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
 		}
 
 		err = qgroup_rescan_leaf(trans, path);
+		did_leaf_rescans = true;
 
 		if (err > 0)
 			btrfs_commit_transaction(trans);
@@ -3397,16 +3409,23 @@ out:
 	mutex_unlock(&fs_info->qgroup_rescan_lock);
 
 	/*
-	 * only update status, since the previous part has already updated the
-	 * qgroup info.
+	 * Only update status, since the previous part has already updated the
+	 * qgroup info, and only if we did any actual work. This also prevents
+	 * race with a concurrent quota disable, which has already set
+	 * fs_info->quota_root to NULL and cleared BTRFS_FS_QUOTA_ENABLED at
+	 * btrfs_quota_disable().
 	 */
-	trans = btrfs_start_transaction(fs_info->quota_root, 1);
-	if (IS_ERR(trans)) {
-		err = PTR_ERR(trans);
+	if (did_leaf_rescans) {
+		trans = btrfs_start_transaction(fs_info->quota_root, 1);
+		if (IS_ERR(trans)) {
+			err = PTR_ERR(trans);
+			trans = NULL;
+			btrfs_err(fs_info,
+				  "fail to start transaction for status update: %d",
+				  err);
+		}
+	} else {
 		trans = NULL;
-		btrfs_err(fs_info,
-			  "fail to start transaction for status update: %d",
-			  err);
 	}
 
 	mutex_lock(&fs_info->qgroup_rescan_lock);