diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b7e14189da32..ce716c4e3b13 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3035,8 +3035,9 @@ int btrfs_dirty_pages(struct inode *inode, struct page **pages,
 		      size_t num_pages, loff_t pos, size_t write_bytes,
 		      struct extent_state **cached);
 int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end);
-int btrfs_check_can_nocow(struct btrfs_inode *inode, loff_t pos,
-			  size_t *write_bytes, bool nowait);
+int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,
+			   size_t *write_bytes);
+void btrfs_check_nocow_unlock(struct btrfs_inode *inode);
 
 /* tree-defrag.c */
 int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 2bee888cb929..3c84f0df1292 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1533,29 +1533,8 @@ lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
 	return ret;
 }
 
-/*
- * Check if we can do nocow write into the range [@pos, @pos + @write_bytes)
- *
- * @pos:	 File offset
- * @write_bytes: The length to write, will be updated to the nocow writeable
- *		 range
- * @nowait:	 Whether this function could sleep.
- *
- * This function will flush ordered extents in the range to ensure proper
- * nocow checks for (nowait == false) case.
- *
- * Return:
- * >0 and update @write_bytes if we can do nocow write.
- * 0 if we can't do nocow write.
- * -EAGAIN if we can't get the needed lock or there are ordered extents for
- * (nowait == true) case.
- * <0 if other error happened.
- *
- * NOTE: For wait (nowait==false) calls, callers need to release the drew write
- * 	 lock of inode->root->snapshot_lock when return value > 0.
- */
-int btrfs_check_can_nocow(struct btrfs_inode *inode, loff_t pos,
-			  size_t *write_bytes, bool nowait)
+static int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
+			   size_t *write_bytes, bool nowait)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 	struct btrfs_root *root = inode->root;
@@ -1563,6 +1542,9 @@ int btrfs_check_can_nocow(struct btrfs_inode *inode, loff_t pos,
 	u64 num_bytes;
 	int ret;
 
+	if (!(inode->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC)))
+		return 0;
+
 	if (!nowait && !btrfs_drew_try_write_lock(&root->snapshot_lock))
 		return -EAGAIN;
 
@@ -1605,6 +1587,41 @@ int btrfs_check_can_nocow(struct btrfs_inode *inode, loff_t pos,
 	return ret;
 }
 
+static int check_nocow_nolock(struct btrfs_inode *inode, loff_t pos,
+			      size_t *write_bytes)
+{
+	return check_can_nocow(inode, pos, write_bytes, true);
+}
+
+/*
+ * Check if we can do nocow write into the range [@pos, @pos + @write_bytes)
+ *
+ * @pos:	 File offset
+ * @write_bytes: The length to write, will be updated to the nocow writeable
+ *		 range
+ *
+ * This function will flush ordered extents in the range to ensure proper
+ * nocow checks.
+ *
+ * Return:
+ * >0 and update @write_bytes if we can do nocow write.
+ * 0 if we can't do nocow write.
+ * -EAGAIN if we can't get the needed lock.
+ * <0 if other error happened.
+ *
+ * NOTE: Callers need to release the lock by btrfs_check_nocow_unlock().
+ */
+int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,
+			   size_t *write_bytes)
+{
+	return check_can_nocow(inode, pos, write_bytes, false);
+}
+
+void btrfs_check_nocow_unlock(struct btrfs_inode *inode)
+{
+	btrfs_drew_write_unlock(&inode->root->snapshot_lock);
+}
+
 static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
 					       struct iov_iter *i)
 {
@@ -1612,7 +1629,6 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
 	loff_t pos = iocb->ki_pos;
 	struct inode *inode = file_inode(file);
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct page **pages = NULL;
 	struct extent_changeset *data_reserved = NULL;
 	u64 release_bytes = 0;
@@ -1668,10 +1684,8 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
 		ret = btrfs_check_data_free_space(inode, &data_reserved, pos,
 						  write_bytes);
 		if (ret < 0) {
-			if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
-						      BTRFS_INODE_PREALLOC)) &&
-			    btrfs_check_can_nocow(BTRFS_I(inode), pos,
-						  &write_bytes, false) > 0) {
+			if (btrfs_check_nocow_lock(BTRFS_I(inode), pos,
+						   &write_bytes) > 0) {
 				/*
 				 * For nodata cow case, no need to reserve
 				 * data space.
@@ -1700,7 +1714,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
 						data_reserved, pos,
 						write_bytes);
 			else
-				btrfs_drew_write_unlock(&root->snapshot_lock);
+				btrfs_check_nocow_unlock(BTRFS_I(inode));
 			break;
 		}
 
@@ -1804,7 +1818,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
 
 		release_bytes = 0;
 		if (only_release_metadata)
-			btrfs_drew_write_unlock(&root->snapshot_lock);
+			btrfs_check_nocow_unlock(BTRFS_I(inode));
 
 		if (only_release_metadata && copied > 0) {
 			lockstart = round_down(pos,
@@ -1831,7 +1845,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
 
 	if (release_bytes) {
 		if (only_release_metadata) {
-			btrfs_drew_write_unlock(&root->snapshot_lock);
+			btrfs_check_nocow_unlock(BTRFS_I(inode));
 			btrfs_delalloc_release_metadata(BTRFS_I(inode),
 					release_bytes, true);
 		} else {
@@ -1946,10 +1960,8 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 		 * We will allocate space in case nodatacow is not set,
 		 * so bail
 		 */
-		if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
-					      BTRFS_INODE_PREALLOC)) ||
-		    btrfs_check_can_nocow(BTRFS_I(inode), pos, &nocow_bytes,
-					  true) <= 0) {
+		if (check_nocow_nolock(BTRFS_I(inode), pos, &nocow_bytes)
+		    <= 0) {
 			inode_unlock(inode);
 			return -EAGAIN;
 		}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 339d739b2d29..95d3b68eee4f 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4541,10 +4541,8 @@ int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
 	ret = btrfs_check_data_free_space(inode, &data_reserved, block_start,
 					  blocksize);
 	if (ret < 0) {
-		if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
-					      BTRFS_INODE_PREALLOC)) &&
-		    btrfs_check_can_nocow(BTRFS_I(inode), block_start,
-					  &write_bytes, false) > 0) {
+		if (btrfs_check_nocow_lock(BTRFS_I(inode), block_start,
+					   &write_bytes) > 0) {
 			/* For nocow case, no need to reserve data space. */
 			only_release_metadata = true;
 		} else {
@@ -4645,7 +4643,7 @@ int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
 	put_page(page);
 out:
 	if (only_release_metadata)
-		btrfs_drew_write_unlock(&BTRFS_I(inode)->root->snapshot_lock);
+		btrfs_check_nocow_unlock(BTRF_I(inode));
 	extent_changeset_free(data_reserved);
 	return ret;
 }
