iomap: Simplify iomap_writepage_map()

Rename end_offset to end_pos and file_offset to pos to match the rest
of the file.  Simplify the loop by calculating nblocks up front instead
of each time around the loop.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index b403b83eedaf7c90f2222342a49650217de782d8..682e15e50cf6063b60870683d732a33f50d2a06c 100644 (file)
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1307,37 +1307,36 @@ iomap_add_to_ioend(struct inode *inode, loff_t offset, struct page *page,
 static int
 iomap_writepage_map(struct iomap_writepage_ctx *wpc,
                struct writeback_control *wbc, struct inode *inode,
-               struct page *page, u64 end_offset)
+               struct page *page, u64 end_pos)
 {
        struct folio *folio = page_folio(page);
        struct iomap_page *iop = iomap_page_create(inode, folio);
        struct iomap_ioend *ioend, *next;
        unsigned len = i_blocksize(inode);
-       u64 file_offset; /* file offset of page */
+       unsigned nblocks = i_blocks_per_folio(inode, folio);
+       u64 pos = folio_pos(folio);
        int error = 0, count = 0, i;
        LIST_HEAD(submit_list);
 
        WARN_ON_ONCE(iop && atomic_read(&iop->write_bytes_pending) != 0);
 
        /*
-        * Walk through the page to find areas to write back. If we run off the
-        * end of the current map or find the current map invalid, grab a new
-        * one.
+        * Walk through the folio to find areas to write back. If we
+        * run off the end of the current map or find the current map
+        * invalid, grab a new one.
         */
-       for (i = 0, file_offset = page_offset(page);
-            i < (PAGE_SIZE >> inode->i_blkbits) && file_offset < end_offset;
-            i++, file_offset += len) {
+       for (i = 0; i < nblocks && pos < end_pos; i++, pos += len) {
                if (iop && !test_bit(i, iop->uptodate))
                        continue;
 
-               error = wpc->ops->map_blocks(wpc, inode, file_offset);
+               error = wpc->ops->map_blocks(wpc, inode, pos);
                if (error)
                        break;
                if (WARN_ON_ONCE(wpc->iomap.type == IOMAP_INLINE))
                        continue;
                if (wpc->iomap.type == IOMAP_HOLE)
                        continue;
-               iomap_add_to_ioend(inode, file_offset, page, iop, wpc, wbc,
+               iomap_add_to_ioend(inode, pos, page, iop, wpc, wbc,
                                 &submit_list);
                count++;
        }
@@ -1361,7 +1360,7 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
                 * now.
                 */
                if (wpc->ops->discard_folio)
-                       wpc->ops->discard_folio(folio, file_offset);
+                       wpc->ops->discard_folio(folio, pos);
                if (!count) {
                        ClearPageUptodate(page);
                        unlock_page(page);