[PATCH v6 01/10] iomap: factor out iomap length helper

Brian Foster
2025-02-07T14:30:34Z

In preparation to support more granular iomap iter advancing, factor
the pos/len values as parameters to length calculation.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
---
include/linux/iomap.h | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 75bf54e76f3b..f5ca71ac2fa2 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -231,18 +231,33 @@ struct iomap_iter {
int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops);

/**
- * iomap_length - length of the current iomap iteration
+ * iomap_length_trim - trimmed length of the current iomap iteration
* @iter: iteration structure
+ * @pos: File position to trim from.
+ * @len: Length of the mapping to trim to.
*
- * Returns the length that the operation applies to for the current iteration.
+ * Returns a trimmed length that the operation applies to for the current
+ * iteration.
*/
-static inline u64 iomap_length(const struct iomap_iter *iter)
+static inline u64 iomap_length_trim(const struct iomap_iter *iter, loff_t pos,
+ u64 len)
{
u64 end = iter->iomap.offset + iter->iomap.length;

if (iter->srcmap.type != IOMAP_HOLE)
end = min(end, iter->srcmap.offset + iter->srcmap.length);
- return min(iter->len, end - iter->pos);
+ return min(len, end - pos);
+}
+
+/**
+ * iomap_length - length of the current iomap iteration
+ * @iter: iteration structure
+ *
+ * Returns the length that the operation applies to for the current iteration.
+ */
+static inline u64 iomap_length(const struct iomap_iter *iter)
+{
+ return iomap_length_trim(iter, iter->pos, iter->len);
}

/**
--
2.48.1