[PATCH v2 6/7] iomap: advance the iter directly on unshare range

Brian Foster
2025-01-22T13:32:31Z

Modify unshare range to advance the iter directly. Replace the local
pos and length calculations with direct advances and loop based on
iter state instead.

Signed-off-by: Brian Foster <bfoster@redhat.com>
---
fs/iomap/buffered-io.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 5ce5ac13765a..ea140d3098ff 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1267,20 +1267,19 @@ EXPORT_SYMBOL_GPL(iomap_write_delalloc_release);
static loff_t iomap_unshare_iter(struct iomap_iter *iter)
{
struct iomap *iomap = &iter->iomap;
- loff_t pos = iter->pos;
- loff_t length = iomap_length(iter);
- loff_t written = 0;
+ size_t bytes = iomap_length(iter);

if (!iomap_want_unshare_iter(iter))
- return length;
+ return bytes;

do {
struct folio *folio;
int status;
size_t offset;
- size_t bytes = min_t(u64, SIZE_MAX, length);
+ loff_t pos = iter->pos;
bool ret;

+ bytes = min_t(u64, SIZE_MAX, bytes);
status = iomap_write_begin(iter, pos, bytes, &folio);
if (unlikely(status))
return status;
@@ -1298,14 +1297,10 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter)

cond_resched();

- pos += bytes;
- written += bytes;
- length -= bytes;
-
balance_dirty_pages_ratelimited(iter->inode->i_mapping);
- } while (length > 0);
+ } while ((bytes = iomap_iter_advance(iter, bytes)) > 0);

- return written;
+ return bytes < 0 ? bytes : 0;
}

int
--
2.47.1