[PATCH 10/12] mm/filemap: add filemap_fdatawrite_range_kick() helper

Jens Axboe
2024-12-03T15:33:00Z

Works like filemap_fdatawrite_range(), except it's a non-integrity data
writeback and hence only starts writeback on the specified range. Will
help facilitate generically starting uncached writeback from
generic_write_sync(), as header dependencies preclude doing this inline
from fs.h.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/linux/fs.h | 2 ++
mm/filemap.c | 18 ++++++++++++++++++
2 files changed, 20 insertions(+)

diff --git a/include/linux/fs.h b/include/linux/fs.h
index b64a78582f06..40383f5cc6a2 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2878,6 +2878,8 @@ extern int __must_check file_fdatawait_range(struct file *file, loff_t lstart,
extern int __must_check file_check_and_advance_wb_err(struct file *file);
extern int __must_check file_write_and_wait_range(struct file *file,
loff_t start, loff_t end);
+int filemap_fdatawrite_range_kick(struct address_space *mapping, loff_t start,
+ loff_t end);

static inline int file_write_and_wait(struct file *file)
{
diff --git a/mm/filemap.c b/mm/filemap.c
index eb6a8d39f9d0..826df99e294f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -449,6 +449,24 @@ int filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
}
EXPORT_SYMBOL(filemap_fdatawrite_range);

+/**
+ * filemap_fdatawrite_range_kick - start writeback on a range
+ * @mapping: target address_space
+ * @start: index to start writeback on
+ * @end: last (non-inclusive) index for writeback
+ *
+ * This is a non-integrity writeback helper, to start writing back folios
+ * for the indicated range.
+ *
+ * Return: %0 on success, negative error code otherwise.
+ */
+int filemap_fdatawrite_range_kick(struct address_space *mapping, loff_t start,
+ loff_t end)
+{
+ return __filemap_fdatawrite_range(mapping, start, end, WB_SYNC_NONE);
+}
+EXPORT_SYMBOL_GPL(filemap_fdatawrite_range_kick);
+
/**
* filemap_flush - mostly a non-blocking flush
* @mapping: target address_space
--
2.45.2