fuse: support large folios for writethrough writes

Add support for folios larger than one page size for writethrough
writes.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 6b77daa2fbceb2b4186d17d5c4ae809d191c8977..2d9bc484e87adf7d530e158a1995cc646b0c6e3a 100644 (file)
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1146,7 +1146,8 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
                size_t tmp;
                struct folio *folio;
                pgoff_t index = pos >> PAGE_SHIFT;
-               unsigned bytes = min(PAGE_SIZE - offset, num);
+               unsigned int bytes;
+               unsigned int folio_offset;
 
  again:
                folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
@@ -1159,7 +1160,10 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
                if (mapping_writably_mapped(mapping))
                        flush_dcache_folio(folio);
 
-               tmp = copy_folio_from_iter_atomic(folio, offset, bytes, ii);
+               folio_offset = ((index - folio->index) << PAGE_SHIFT) + offset;
+               bytes = min(folio_size(folio) - folio_offset, num);
+
+               tmp = copy_folio_from_iter_atomic(folio, folio_offset, bytes, ii);
                flush_dcache_folio(folio);
 
                if (!tmp) {
@@ -1179,6 +1183,7 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
                }
 
                ap->folios[ap->num_folios] = folio;
+               ap->descs[ap->num_folios].offset = folio_offset;
                ap->descs[ap->num_folios].length = tmp;
                ap->num_folios++;
 
@@ -1186,11 +1191,11 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
                pos += tmp;
                num -= tmp;
                offset += tmp;
-               if (offset == PAGE_SIZE)
+               if (offset == folio_size(folio))
                        offset = 0;
 
-               /* If we copied full page, mark it uptodate */
-               if (tmp == PAGE_SIZE)
+               /* If we copied full folio, mark it uptodate */
+               if (tmp == folio_size(folio))
                        folio_mark_uptodate(folio);
 
                if (folio_test_uptodate(folio)) {