VisionFive2 Linux kernel

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 117d423fdb93..e656134cadaa 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1488,15 +1488,15 @@ static int btrfs_find_all_roots_safe(struct btrfs_trans_handle *trans,
 int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
 			 struct btrfs_fs_info *fs_info, u64 bytenr,
 			 u64 time_seq, struct ulist **roots,
-			 bool ignore_offset)
+			 bool ignore_offset, bool skip_commit_root_sem)
 {
 	int ret;
 
-	if (!trans)
+	if (!trans && !skip_commit_root_sem)
 		down_read(&fs_info->commit_root_sem);
 	ret = btrfs_find_all_roots_safe(trans, fs_info, bytenr,
 					time_seq, roots, ignore_offset);
-	if (!trans)
+	if (!trans && !skip_commit_root_sem)
 		up_read(&fs_info->commit_root_sem);
 	return ret;
 }
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index 17abde7f794c..ff5f07f9940b 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -47,7 +47,8 @@ int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
 			 const u64 *extent_item_pos, bool ignore_offset);
 int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
 			 struct btrfs_fs_info *fs_info, u64 bytenr,
-			 u64 time_seq, struct ulist **roots, bool ignore_offset);
+			 u64 time_seq, struct ulist **roots, bool ignore_offset,
+			 bool skip_commit_root_sem);
 char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
 			u32 name_len, unsigned long name_off,
 			struct extent_buffer *eb_in, u64 parent,
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index c92d9d4f5f46..6689cac64c15 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -1000,7 +1000,7 @@ int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
 		kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
 
 	if (qrecord_inserted)
-		btrfs_qgroup_trace_extent_post(fs_info, record);
+		btrfs_qgroup_trace_extent_post(trans, record);
 
 	return 0;
 }
@@ -1095,7 +1095,7 @@ int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
 
 
 	if (qrecord_inserted)
-		return btrfs_qgroup_trace_extent_post(fs_info, record);
+		return btrfs_qgroup_trace_extent_post(trans, record);
 	return 0;
 }
 
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 3ded812f522c..dde8b8334d29 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1704,17 +1704,39 @@ int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
-int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
+int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
 				   struct btrfs_qgroup_extent_record *qrecord)
 {
 	struct ulist *old_root;
 	u64 bytenr = qrecord->bytenr;
 	int ret;
 
-	ret = btrfs_find_all_roots(NULL, fs_info, bytenr, 0, &old_root, false);
+	/*
+	 * We are always called in a context where we are already holding a
+	 * transaction handle. Often we are called when adding a data delayed
+	 * reference from btrfs_truncate_inode_items() (truncating or unlinking),
+	 * in which case we will be holding a write lock on extent buffer from a
+	 * subvolume tree. In this case we can't allow btrfs_find_all_roots() to
+	 * acquire fs_info->commit_root_sem, because that is a higher level lock
+	 * that must be acquired before locking any extent buffers.
+	 *
+	 * So we want btrfs_find_all_roots() to not acquire the commit_root_sem
+	 * but we can't pass it a non-NULL transaction handle, because otherwise
+	 * it would not use commit roots and would lock extent buffers, causing
+	 * a deadlock if it ends up trying to read lock the same extent buffer
+	 * that was previously write locked at btrfs_truncate_inode_items().
+	 *
+	 * So pass a NULL transaction handle to btrfs_find_all_roots() and
+	 * explicitly tell it to not acquire the commit_root_sem - if we are
+	 * holding a transaction handle we don't need its protection.
+	 */
+	ASSERT(trans != NULL);
+
+	ret = btrfs_find_all_roots(NULL, trans->fs_info, bytenr, 0, &old_root,
+				   false, true);
 	if (ret < 0) {
-		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
-		btrfs_warn(fs_info,
+		trans->fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
+		btrfs_warn(trans->fs_info,
 "error accounting new delayed refs extent (err code: %d), quota inconsistent",
 			ret);
 		return 0;
@@ -1758,7 +1780,7 @@ int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
 		kfree(record);
 		return 0;
 	}
-	return btrfs_qgroup_trace_extent_post(fs_info, record);
+	return btrfs_qgroup_trace_extent_post(trans, record);
 }
 
 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
@@ -2629,7 +2651,7 @@ int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
 				/* Search commit root to find old_roots */
 				ret = btrfs_find_all_roots(NULL, fs_info,
 						record->bytenr, 0,
-						&record->old_roots, false);
+						&record->old_roots, false, false);
 				if (ret < 0)
 					goto cleanup;
 			}
@@ -2645,7 +2667,7 @@ int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
 			 * current root. It's safe inside commit_transaction().
 			 */
 			ret = btrfs_find_all_roots(trans, fs_info,
-				record->bytenr, BTRFS_SEQ_LAST, &new_roots, false);
+			   record->bytenr, BTRFS_SEQ_LAST, &new_roots, false, false);
 			if (ret < 0)
 				goto cleanup;
 			if (qgroup_to_skip) {
@@ -3179,7 +3201,7 @@ static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
 			num_bytes = found.offset;
 
 		ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
-					   &roots, false);
+					   &roots, false, false);
 		if (ret < 0)
 			goto out;
 		/* For rescan, just pass old_roots as NULL */
diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h
index 7283e4f549af..880e9df0dac1 100644
--- a/fs/btrfs/qgroup.h
+++ b/fs/btrfs/qgroup.h
@@ -298,7 +298,7 @@ int btrfs_qgroup_trace_extent_nolock(
  * using current root, then we can move all expensive backref walk out of
  * transaction committing, but not now as qgroup accounting will be wrong again.
  */
-int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
+int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
 				   struct btrfs_qgroup_extent_record *qrecord);
 
 /*
diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c
index f3137285a9e2..98b5aaba46f1 100644
--- a/fs/btrfs/tests/qgroup-tests.c
+++ b/fs/btrfs/tests/qgroup-tests.c
@@ -224,7 +224,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 	 * quota.
 	 */
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
-			false);
+			false, false);
 	if (ret) {
 		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
@@ -237,7 +237,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 		return ret;
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
-			false);
+			false, false);
 	if (ret) {
 		ulist_free(old_roots);
 		ulist_free(new_roots);
@@ -261,7 +261,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 	new_roots = NULL;
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
-			false);
+			false, false);
 	if (ret) {
 		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
@@ -273,7 +273,7 @@ static int test_no_shared_qgroup(struct btrfs_root *root,
 		return -EINVAL;
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
-			false);
+			false, false);
 	if (ret) {
 		ulist_free(old_roots);
 		ulist_free(new_roots);
@@ -325,7 +325,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 	}
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
-			false);
+			false, false);
 	if (ret) {
 		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
@@ -338,7 +338,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 		return ret;
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
-			false);
+			false, false);
 	if (ret) {
 		ulist_free(old_roots);
 		ulist_free(new_roots);
@@ -360,7 +360,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 	}
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
-			false);
+			false, false);
 	if (ret) {
 		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
@@ -373,7 +373,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 		return ret;
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
-			false);
+			false, false);
 	if (ret) {
 		ulist_free(old_roots);
 		ulist_free(new_roots);
@@ -401,7 +401,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 	}
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &old_roots,
-			false);
+			false, false);
 	if (ret) {
 		ulist_free(old_roots);
 		test_err("couldn't find old roots: %d", ret);
@@ -414,7 +414,7 @@ static int test_multiple_refs(struct btrfs_root *root,
 		return ret;
 
 	ret = btrfs_find_all_roots(&trans, fs_info, nodesize, 0, &new_roots,
-			false);
+			false, false);
 	if (ret) {
 		ulist_free(old_roots);
 		ulist_free(new_roots);