iomap: add public helpers for uptodate state manipulation

Add a new iomap_start_folio_write helper to abstract away the
write_bytes_pending handling, and export it and the existing
iomap_finish_folio_write for non-iomap writeback in fuse.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/20250710133343.399917-7-hch@lst.de
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 650a67b7d223d5c5478f201e50d769d57de56387..060bfcc353dab152f01e13e23ee57bb950f28207 100644 (file)
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1527,7 +1527,18 @@ out_unlock:
 }
 EXPORT_SYMBOL_GPL(iomap_page_mkwrite);
 
-static void iomap_finish_folio_write(struct inode *inode, struct folio *folio,
+void iomap_start_folio_write(struct inode *inode, struct folio *folio,
+               size_t len)
+{
+       struct iomap_folio_state *ifs = folio->private;
+
+       WARN_ON_ONCE(i_blocks_per_folio(inode, folio) > 1 && !ifs);
+       if (ifs)
+               atomic_add(len, &ifs->write_bytes_pending);
+}
+EXPORT_SYMBOL_GPL(iomap_start_folio_write);
+
+void iomap_finish_folio_write(struct inode *inode, struct folio *folio,
                size_t len)
 {
        struct iomap_folio_state *ifs = folio->private;
@@ -1538,6 +1549,7 @@ static void iomap_finish_folio_write(struct inode *inode, struct folio *folio,
        if (!ifs || atomic_sub_and_test(len, &ifs->write_bytes_pending))
                folio_end_writeback(folio);
 }
+EXPORT_SYMBOL_GPL(iomap_finish_folio_write);
 
 /*
  * We're now finished for good with this ioend structure.  Update the page
@@ -1660,7 +1672,6 @@ ssize_t iomap_add_to_ioend(struct iomap_writepage_ctx *wpc, struct folio *folio,
                loff_t pos, loff_t end_pos, unsigned int dirty_len)
 {
        struct iomap_ioend *ioend = wpc->wb_ctx;
-       struct iomap_folio_state *ifs = folio->private;
        size_t poff = offset_in_folio(folio, pos);
        unsigned int ioend_flags = 0;
        unsigned int map_len = min_t(u64, dirty_len,
@@ -1703,8 +1714,7 @@ new_ioend:
        if (!bio_add_folio(&ioend->io_bio, folio, map_len, poff))
                goto new_ioend;
 
-       if (ifs)
-               atomic_add(map_len, &ifs->write_bytes_pending);
+       iomap_start_folio_write(wpc->inode, folio, map_len);
 
        /*
         * Clamp io_offset and io_size to the incore EOF so that ondisk
@@ -1877,7 +1887,7 @@ static int iomap_writepage_map(struct iomap_writepage_ctx *wpc,
                 * all blocks.
                 */
                WARN_ON_ONCE(atomic_read(&ifs->write_bytes_pending) != 0);
-               atomic_inc(&ifs->write_bytes_pending);
+               iomap_start_folio_write(inode, folio, 1);
        }
 
        /*

diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 9f32dd8dc07509c74e8ae0c902ed5ff4a0b83f91..cbf9d299a6168389fd95ecd0db091c54f89a39ee 100644 (file)
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -461,6 +461,11 @@ ssize_t iomap_add_to_ioend(struct iomap_writepage_ctx *wpc, struct folio *folio,
                loff_t pos, loff_t end_pos, unsigned int dirty_len);
 int iomap_ioend_writeback_submit(struct iomap_writepage_ctx *wpc, int error);
 
+void iomap_start_folio_write(struct inode *inode, struct folio *folio,
+               size_t len);
+void iomap_finish_folio_write(struct inode *inode, struct folio *folio,
+               size_t len);
+
 int iomap_writepages(struct iomap_writepage_ctx *wpc);
 
 /*