fuse: support folios in struct fuse_args_pages and fuse_copy_pages()

This adds support in struct fuse_args_pages and fuse_copy_pages() for
using folios instead of pages for transferring data. Both folios and
pages must be supported right now in struct fuse_args_pages and
fuse_copy_pages() until all request types have been converted to use
folios. Once all have been converted, then
struct fuse_args_pages and fuse_copy_pages() will only support folios.

Right now in fuse, all folios are one page (large folios are not yet
supported). As such, copying folio->page is sufficient for copying
the entire folio in fuse_copy_pages().

No functional changes.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index e25804097ffbc49171431fad4017fbfc283f49c0..70da1184a3f61b7c5460696617f1ade147224983 100644 (file)
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1028,17 +1028,41 @@ static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
        struct fuse_req *req = cs->req;
        struct fuse_args_pages *ap = container_of(req->args, typeof(*ap), args);
 
+       if (ap->uses_folios) {
+               for (i = 0; i < ap->num_folios && (nbytes || zeroing); i++) {
+                       int err;
+                       unsigned int offset = ap->folio_descs[i].offset;
+                       unsigned int count = min(nbytes, ap->folio_descs[i].length);
+                       struct page *orig, *pagep;
 
-       for (i = 0; i < ap->num_pages && (nbytes || zeroing); i++) {
-               int err;
-               unsigned int offset = ap->descs[i].offset;
-               unsigned int count = min(nbytes, ap->descs[i].length);
+                       orig = pagep = &ap->folios[i]->page;
 
-               err = fuse_copy_page(cs, &ap->pages[i], offset, count, zeroing);
-               if (err)
-                       return err;
+                       err = fuse_copy_page(cs, &pagep, offset, count, zeroing);
+                       if (err)
+                               return err;
+
+                       nbytes -= count;
+
+                       /*
+                        *  fuse_copy_page may have moved a page from a pipe
+                        *  instead of copying into our given page, so update
+                        *  the folios if it was replaced.
+                        */
+                       if (pagep != orig)
+                               ap->folios[i] = page_folio(pagep);
+               }
+       } else {
+               for (i = 0; i < ap->num_pages && (nbytes || zeroing); i++) {
+                       int err;
+                       unsigned int offset = ap->descs[i].offset;
+                       unsigned int count = min(nbytes, ap->descs[i].length);
 
-               nbytes -= count;
+                       err = fuse_copy_page(cs, &ap->pages[i], offset, count, zeroing);
+                       if (err)
+                               return err;
+
+                       nbytes -= count;
+               }
        }
        return 0;
 }

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 671daa4d07adba540aafe341dc85bfb00c455c99..24a3da8400d16963a55389f2d914e5089268f897 100644 (file)
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -291,6 +291,12 @@ struct fuse_page_desc {
        unsigned int offset;
 };
 
+/** FUSE folio descriptor */
+struct fuse_folio_desc {
+       unsigned int length;
+       unsigned int offset;
+};
+
 struct fuse_args {
        uint64_t nodeid;
        uint32_t opcode;
@@ -319,9 +325,19 @@ struct fuse_args {
 
 struct fuse_args_pages {
        struct fuse_args args;
-       struct page **pages;
-       struct fuse_page_desc *descs;
-       unsigned int num_pages;
+       union {
+               struct {
+                       struct page **pages;
+                       struct fuse_page_desc *descs;
+                       unsigned int num_pages;
+               };
+               struct {
+                       struct folio **folios;
+                       struct fuse_folio_desc *folio_descs;
+                       unsigned int num_folios;
+               };
+       };
+       bool uses_folios;
 };
 
 struct fuse_release_args {