NFS: Support folios in nfs_generic_pgio()

Add support for multi-page folios in the generic NFS i/o engine.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index ae7d4a8c728c2fa78f04457cc19224bdbe60d619..6197b165c8c8262c70daba69495dfcf089a0abf0 100644 (file)
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -807,11 +807,10 @@ unsigned char nfs_umode_to_dtype(umode_t mode)
  * Determine the number of pages in an array of length 'len' and
  * with a base offset of 'base'
  */
-static inline
-unsigned int nfs_page_array_len(unsigned int base, size_t len)
+static inline unsigned int nfs_page_array_len(unsigned int base, size_t len)
 {
-       return ((unsigned long)len + (unsigned long)base +
-               PAGE_SIZE - 1) >> PAGE_SHIFT;
+       return ((unsigned long)len + (unsigned long)base + PAGE_SIZE - 1) >>
+              PAGE_SHIFT;
 }
 
 /*

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 315e58d737185d2b8cc1c6a2c73f32fe47e88fd6..1744627222663f9b801de2482d2aed348028a15a 100644 (file)
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -31,6 +31,42 @@
 static struct kmem_cache *nfs_page_cachep;
 static const struct rpc_call_ops nfs_pgio_common_ops;
 
+struct nfs_page_iter_page {
+       const struct nfs_page *req;
+       size_t count;
+};
+
+static void nfs_page_iter_page_init(struct nfs_page_iter_page *i,
+                                   const struct nfs_page *req)
+{
+       i->req = req;
+       i->count = 0;
+}
+
+static void nfs_page_iter_page_advance(struct nfs_page_iter_page *i, size_t sz)
+{
+       const struct nfs_page *req = i->req;
+       size_t tmp = i->count + sz;
+
+       i->count = (tmp < req->wb_bytes) ? tmp : req->wb_bytes;
+}
+
+static struct page *nfs_page_iter_page_get(struct nfs_page_iter_page *i)
+{
+       const struct nfs_page *req = i->req;
+       struct page *page;
+
+       if (i->count != req->wb_bytes) {
+               size_t base = i->count + req->wb_pgbase;
+               size_t len = PAGE_SIZE - offset_in_page(base);
+
+               page = nfs_page_to_page(req, base);
+               nfs_page_iter_page_advance(i, len);
+               return page;
+       }
+       return NULL;
+}
+
 static struct nfs_pgio_mirror *
 nfs_pgio_get_mirror(struct nfs_pageio_descriptor *desc, u32 idx)
 {
@@ -693,13 +729,14 @@ EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
 /**
  * nfs_pgio_rpcsetup - Set up arguments for a pageio call
  * @hdr: The pageio hdr
+ * @pgbase: base
  * @count: Number of bytes to read
  * @how: How to commit data (writes only)
  * @cinfo: Commit information for the call (writes only)
  */
-static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr,
-                             unsigned int count,
-                             int how, struct nfs_commit_info *cinfo)
+static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr, unsigned int pgbase,
+                             unsigned int count, int how,
+                             struct nfs_commit_info *cinfo)
 {
        struct nfs_page *req = hdr->req;
 
@@ -710,7 +747,7 @@ static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr,
        hdr->args.offset = req_offset(req);
        /* pnfs_set_layoutcommit needs this */
        hdr->mds_offset = hdr->args.offset;
-       hdr->args.pgbase = req->wb_pgbase;
+       hdr->args.pgbase = pgbase;
        hdr->args.pages  = hdr->page_array.pagevec;
        hdr->args.count  = count;
        hdr->args.context = get_nfs_open_context(nfs_req_openctx(req));
@@ -896,9 +933,10 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
        struct nfs_commit_info cinfo;
        struct nfs_page_array *pg_array = &hdr->page_array;
        unsigned int pagecount, pageused;
+       unsigned int pg_base = offset_in_page(mirror->pg_base);
        gfp_t gfp_flags = nfs_io_gfp_mask();
 
-       pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count);
+       pagecount = nfs_page_array_len(pg_base, mirror->pg_count);
        pg_array->npages = pagecount;
 
        if (pagecount <= ARRAY_SIZE(pg_array->page_array))
@@ -918,19 +956,26 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
        last_page = NULL;
        pageused = 0;
        while (!list_empty(head)) {
+               struct nfs_page_iter_page i;
+               struct page *page;
+
                req = nfs_list_entry(head->next);
                nfs_list_move_request(req, &hdr->pages);
 
                if (req->wb_pgbase == 0)
                        last_page = NULL;
 
-               if (!last_page || last_page != req->wb_page) {
-                       pageused++;
-                       if (pageused > pagecount)
-                               break;
-                       *pages++ = last_page = req->wb_page;
+               nfs_page_iter_page_init(&i, req);
+               while ((page = nfs_page_iter_page_get(&i)) != NULL) {
+                       if (last_page != page) {
+                               pageused++;
+                               if (pageused > pagecount)
+                                       goto full;
+                               *pages++ = last_page = page;
+                       }
                }
        }
+full:
        if (WARN_ON_ONCE(pageused != pagecount)) {
                nfs_pgio_error(hdr);
                desc->pg_error = -EINVAL;
@@ -942,7 +987,8 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
                desc->pg_ioflags &= ~FLUSH_COND_STABLE;
 
        /* Set up the argument struct */
-       nfs_pgio_rpcsetup(hdr, mirror->pg_count, desc->pg_ioflags, &cinfo);
+       nfs_pgio_rpcsetup(hdr, pg_base, mirror->pg_count, desc->pg_ioflags,
+                         &cinfo);
        desc->pg_rpc_callops = &nfs_pgio_common_ops;
        return 0;
 }