[PATCH v3 14/16] fuse: use iomap for folio laundering

Joanne Koong
2025-06-24T02:23:18Z

Use iomap for folio laundering, which will do granular dirty
writeback when laundering a large folio.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
---
fs/fuse/file.c | 52 ++++++++++++--------------------------------------
1 file changed, 12 insertions(+), 40 deletions(-)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 2b4b950eaeed..35ecc03c0c48 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -2062,45 +2062,6 @@ static struct fuse_writepage_args *fuse_writepage_args_setup(struct folio *folio
return wpa;
}

-static int fuse_writepage_locked(struct folio *folio)
-{
- struct address_space *mapping = folio->mapping;
- struct inode *inode = mapping->host;
- struct fuse_inode *fi = get_fuse_inode(inode);
- struct fuse_writepage_args *wpa;
- struct fuse_args_pages *ap;
- struct fuse_file *ff;
- int error = -EIO;
-
- ff = fuse_write_file_get(fi);
- if (!ff)
- goto err;
-
- wpa = fuse_writepage_args_setup(folio, 0, ff);
- error = -ENOMEM;
- if (!wpa)
- goto err_writepage_args;
-
- ap = &wpa->ia.ap;
- ap->num_folios = 1;
-
- folio_start_writeback(folio);
- fuse_writepage_args_page_fill(wpa, folio, 0, 0, folio_size(folio));
-
- spin_lock(&fi->lock);
- list_add_tail(&wpa->queue_entry, &fi->queued_writes);
- fuse_flush_writepages(inode);
- spin_unlock(&fi->lock);
-
- return 0;
-
-err_writepage_args:
- fuse_file_put(ff, false);
-err:
- mapping_set_error(folio->mapping, error);
- return error;
-}
-
struct fuse_fill_wb_data {
struct fuse_writepage_args *wpa;
struct fuse_file *ff;
@@ -2281,8 +2242,19 @@ static int fuse_writepages(struct address_space *mapping,
static int fuse_launder_folio(struct folio *folio)
{
int err = 0;
+ struct fuse_fill_wb_data data = {
+ .inode = folio->mapping->host,
+ };
+ struct iomap_writepage_ctx wpc = {
+ .inode = folio->mapping->host,
+ .iomap.type = IOMAP_MAPPED,
+ .ops = &fuse_writeback_ops,
+ .wb_ctx = &data,
+ };
+
if (folio_clear_dirty_for_io(folio)) {
- err = fuse_writepage_locked(folio);
+ err = iomap_writeback_folio(&wpc, folio);
+ err = fuse_iomap_writeback_submit(&wpc, err);
if (!err)
folio_wait_writeback(folio);
}
--
2.47.1