1 files changed, 26 insertions, 0 deletions
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 2f9290f69610..59334e2edffb 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -925,6 +925,32 @@ do_alloc:
 	goto out;
 }
 
+/**
+ * gfs2_lblk_to_dblk - convert logical block to disk block
+ * @inode: the inode of the file we're mapping
+ * @lblock: the block relative to the start of the file
+ * @dblock: the returned dblock, if no error
+ *
+ * This function maps a single block from a file logical block (relative to
+ * the start of the file) to a file system absolute block using iomap.
+ *
+ * Returns: the absolute file system block, or an error
+ */
+int gfs2_lblk_to_dblk(struct inode *inode, u32 lblock, u64 *dblock)
+{
+	struct iomap iomap = { };
+	struct metapath mp = { .mp_aheight = 1, };
+	loff_t pos = (loff_t)lblock << inode->i_blkbits;
+	int ret;
+
+	ret = gfs2_iomap_get(inode, pos, i_blocksize(inode), 0, &iomap, &mp);
+	release_metapath(&mp);
+	if (ret == 0)
+		*dblock = iomap.addr >> inode->i_blkbits;
+
+	return ret;
+}
+
 static int gfs2_write_lock(struct inode *inode)
 {
 	struct gfs2_inode *ip = GFS2_I(inode);