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LU-4198 clio: AIO support for direct IO
[fs/lustre-release.git] / lustre / llite / rw26.c
index ab6bec9..8ea28c1 100644 (file)
@@ -168,130 +168,262 @@ static int ll_releasepage(struct page *vmpage, RELEASEPAGE_ARG_TYPE gfp_mask)
        return result;
 }
 
-#define MAX_DIRECTIO_SIZE 2*1024*1024*1024UL
+#if defined(HAVE_DIRECTIO_ITER) || defined(HAVE_IOV_ITER_RW) || \
+       defined(HAVE_DIRECTIO_2ARGS)
+#define HAVE_DIO_ITER 1
+#endif
 
-static ssize_t
-ll_direct_IO_seg(const struct lu_env *env, struct cl_io *io, int rw,
-                struct inode *inode, size_t size, loff_t file_offset,
-                struct page **pages, int page_count)
+/*
+ * ll_free_user_pages - tear down page struct array
+ * @pages: array of page struct pointers underlying target buffer
+ */
+static void ll_free_user_pages(struct page **pages, int npages)
 {
-       struct cl_page *clp;
-       struct cl_2queue *queue;
-       struct cl_object *obj = io->ci_obj;
        int i;
-       ssize_t rc = 0;
-       size_t page_size = cl_page_size(obj);
-       size_t orig_size = size;
-       bool do_io;
-       int io_pages = 0;
 
-       ENTRY;
-       queue = &io->ci_queue;
-       cl_2queue_init(queue);
-       for (i = 0; i < page_count; i++) {
-               LASSERT(!(file_offset & (page_size - 1)));
-               clp = cl_page_find(env, obj, cl_index(obj, file_offset),
-                                  pages[i], CPT_TRANSIENT);
-               if (IS_ERR(clp)) {
-                       rc = PTR_ERR(clp);
+       for (i = 0; i < npages; i++) {
+               if (!pages[i])
                        break;
-               }
+               put_page(pages[i]);
+       }
 
-               rc = cl_page_own(env, io, clp);
-               if (rc) {
-                       LASSERT(clp->cp_state == CPS_FREEING);
-                       cl_page_put(env, clp);
-                       break;
-               }
+#if defined(HAVE_DIO_ITER)
+       kvfree(pages);
+#else
+       OBD_FREE_LARGE(pages, npages * sizeof(*pages));
+#endif
+}
 
-               do_io = true;
+static ssize_t ll_get_user_pages(int rw, struct iov_iter *iter,
+                               struct page ***pages, ssize_t *npages,
+                               size_t maxsize)
+{
+#if defined(HAVE_DIO_ITER)
+       size_t start;
+       size_t result;
 
-               /* check the page type: if the page is a host page, then do
-                * write directly
-                */
-               if (clp->cp_type == CPT_CACHEABLE) {
-                       struct page *vmpage = cl_page_vmpage(clp);
-                       struct page *src_page;
-                       struct page *dst_page;
-                       void *src;
-                       void *dst;
-
-                       src_page = (rw == WRITE) ? pages[i] : vmpage;
-                       dst_page = (rw == WRITE) ? vmpage : pages[i];
-
-                       src = ll_kmap_atomic(src_page, KM_USER0);
-                       dst = ll_kmap_atomic(dst_page, KM_USER1);
-                       memcpy(dst, src, min(page_size, size));
-                       ll_kunmap_atomic(dst, KM_USER1);
-                       ll_kunmap_atomic(src, KM_USER0);
-
-                       /* make sure page will be added to the transfer by
-                        * cl_io_submit()->...->vvp_page_prep_write().
-                        */
-                       if (rw == WRITE)
-                               set_page_dirty(vmpage);
-
-                       if (rw == READ) {
-                               /* do not issue the page for read, since it
-                                * may reread a ra page which has NOT uptodate
-                                * bit set.
-                                */
-                               cl_page_disown(env, io, clp);
-                               do_io = false;
-                       }
-               }
+       /*
+        * iov_iter_get_pages_alloc() is introduced in 3.16 similar
+        * to HAVE_DIO_ITER.
+        */
+       result = iov_iter_get_pages_alloc(iter, pages, maxsize, &start);
+       if (result > 0)
+               *npages = DIV_ROUND_UP(result + start, PAGE_SIZE);
 
-               if (likely(do_io)) {
-                       cl_2queue_add(queue, clp);
+       return result;
+#else
+       unsigned long addr;
+       size_t page_count;
+       size_t size;
+       long result;
 
-                       /*
-                        * Set page clip to tell transfer formation engine
-                        * that page has to be sent even if it is beyond KMS.
-                        */
-                       cl_page_clip(env, clp, 0, min(size, page_size));
+       if (!maxsize)
+               return 0;
 
-                       ++io_pages;
-               }
+       if (!iter->nr_segs)
+               return 0;
 
-               /* drop the reference count for cl_page_find */
-               cl_page_put(env, clp);
-               size -= page_size;
-               file_offset += page_size;
+       addr = (unsigned long)iter->iov->iov_base + iter->iov_offset;
+       if (addr & ~PAGE_MASK)
+               return -EINVAL;
+
+       size = min_t(size_t, maxsize, iter->iov->iov_len);
+       page_count = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+       OBD_ALLOC_LARGE(*pages, page_count * sizeof(**pages));
+       if (*pages == NULL)
+               return -ENOMEM;
+
+       down_read(&current->mm->mmap_sem);
+       result = get_user_pages(current, current->mm, addr, page_count,
+                               rw == READ, 0, *pages, NULL);
+       up_read(&current->mm->mmap_sem);
+
+       if (unlikely(result != page_count)) {
+               ll_free_user_pages(*pages, page_count);
+               *pages = NULL;
+
+               if (result >= 0)
+                       return -EFAULT;
+
+               return result;
+       }
+       *npages = page_count;
+
+       return size;
+#endif
+}
+
+/* iov_iter_alignment() is introduced in 3.16 similar to HAVE_DIO_ITER */
+#if defined(HAVE_DIO_ITER)
+static unsigned long ll_iov_iter_alignment(const struct iov_iter *i)
+{
+       return iov_iter_alignment(i);
+}
+#else /* copied from alignment_iovec() */
+static unsigned long ll_iov_iter_alignment(const struct iov_iter *i)
+{
+       const struct iovec *iov = i->iov;
+       unsigned long res;
+       size_t size = i->count;
+       size_t n;
+
+       if (!size)
+               return 0;
+
+       res = (unsigned long)iov->iov_base + i->iov_offset;
+       n = iov->iov_len - i->iov_offset;
+       if (n >= size)
+               return res | size;
+
+       size -= n;
+       res |= n;
+       while (size > (++iov)->iov_len) {
+               res |= (unsigned long)iov->iov_base | iov->iov_len;
+               size -= iov->iov_len;
        }
+       res |= (unsigned long)iov->iov_base | size;
+
+       return res;
+}
+#endif
+
+#ifndef HAVE_AIO_COMPLETE
+static inline void aio_complete(struct kiocb *iocb, ssize_t res, ssize_t res2)
+{
+       if (iocb->ki_complete)
+               iocb->ki_complete(iocb, res, res2);
+}
+#endif
+
+/** direct IO pages */
+struct ll_dio_pages {
+       struct cl_dio_aio       *ldp_aio;
+       /*
+        * page array to be written. we don't support
+        * partial pages except the last one.
+        */
+       struct page             **ldp_pages;
+       /** # of pages in the array. */
+       size_t                  ldp_count;
+       /* the file offset of the first page. */
+       loff_t                  ldp_file_offset;
+};
+
+static void ll_aio_end(const struct lu_env *env, struct cl_sync_io *anchor)
+{
+       struct cl_dio_aio *aio = container_of(anchor, typeof(*aio), cda_sync);
+       ssize_t ret = anchor->csi_sync_rc;
+
+       ENTRY;
+
+       /* release pages */
+       while (aio->cda_pages.pl_nr > 0) {
+               struct cl_page *page = cl_page_list_first(&aio->cda_pages);
 
-       if (rc == 0 && io_pages) {
-               rc = cl_io_submit_sync(env, io,
-                                      rw == READ ? CRT_READ : CRT_WRITE,
-                                      queue, 0);
+               cl_page_get(page);
+               cl_page_list_del(env, &aio->cda_pages, page);
+               cl_page_delete(env, page);
+               cl_page_put(env, page);
        }
-       if (rc == 0)
-               rc = orig_size;
 
-       cl_2queue_discard(env, io, queue);
-       cl_2queue_disown(env, io, queue);
-       cl_2queue_fini(env, queue);
-       RETURN(rc);
+       if (!is_sync_kiocb(aio->cda_iocb))
+               aio_complete(aio->cda_iocb, ret ?: aio->cda_bytes, 0);
+
+       EXIT;
+}
+
+static struct cl_dio_aio *ll_aio_alloc(struct kiocb *iocb)
+{
+       struct cl_dio_aio *aio;
+
+       OBD_ALLOC_PTR(aio);
+       if (aio != NULL) {
+               /*
+                * Hold one ref so that it won't be released until
+                * every pages is added.
+                */
+               cl_sync_io_init_notify(&aio->cda_sync, 1, is_sync_kiocb(iocb) ?
+                                      NULL : aio, ll_aio_end);
+               cl_page_list_init(&aio->cda_pages);
+               aio->cda_iocb = iocb;
+       }
+       return aio;
 }
 
-/*  ll_free_user_pages - tear down page struct array
- *  @pages: array of page struct pointers underlying target buffer */
-static void ll_free_user_pages(struct page **pages, int npages, int do_dirty)
+static int
+ll_direct_rw_pages(const struct lu_env *env, struct cl_io *io, size_t size,
+                  int rw, struct inode *inode, struct ll_dio_pages *pv)
 {
+       struct cl_page    *page;
+       struct cl_2queue  *queue = &io->ci_queue;
+       struct cl_object  *obj = io->ci_obj;
+       struct cl_sync_io *anchor = &pv->ldp_aio->cda_sync;
+       loff_t offset   = pv->ldp_file_offset;
+       int io_pages    = 0;
+       size_t page_size = cl_page_size(obj);
        int i;
+       ssize_t rc = 0;
 
-       for (i = 0; i < npages; i++) {
-               if (pages[i] == NULL)
+       ENTRY;
+
+       cl_2queue_init(queue);
+       for (i = 0; i < pv->ldp_count; i++) {
+               LASSERT(!(offset & (PAGE_SIZE - 1)));
+               page = cl_page_find(env, obj, cl_index(obj, offset),
+                                   pv->ldp_pages[i], CPT_TRANSIENT);
+               if (IS_ERR(page)) {
+                       rc = PTR_ERR(page);
                        break;
-               if (do_dirty)
-                       set_page_dirty_lock(pages[i]);
-               put_page(pages[i]);
+               }
+               LASSERT(page->cp_type == CPT_TRANSIENT);
+               rc = cl_page_own(env, io, page);
+               if (rc) {
+                       cl_page_put(env, page);
+                       break;
+               }
+
+               page->cp_sync_io = anchor;
+               cl_2queue_add(queue, page);
+               /*
+                * Set page clip to tell transfer formation engine
+                * that page has to be sent even if it is beyond KMS.
+                */
+               cl_page_clip(env, page, 0, min(size, page_size));
+               ++io_pages;
+
+               /* drop the reference count for cl_page_find */
+               cl_page_put(env, page);
+               offset += page_size;
+               size -= page_size;
+       }
+       if (rc == 0 && io_pages > 0) {
+               int iot = rw == READ ? CRT_READ : CRT_WRITE;
+
+               atomic_add(io_pages, &anchor->csi_sync_nr);
+               rc = cl_io_submit_rw(env, io, iot, queue);
+               if (rc == 0) {
+                       cl_page_list_splice(&queue->c2_qout,
+                                       &pv->ldp_aio->cda_pages);
+               } else {
+                       atomic_add(-queue->c2_qin.pl_nr,
+                                  &anchor->csi_sync_nr);
+                       cl_page_list_for_each(page, &queue->c2_qin)
+                               page->cp_sync_io = NULL;
+               }
+               /* handle partially submitted reqs */
+               if (queue->c2_qin.pl_nr > 0) {
+                       CERROR(DFID " failed to submit %d dio pages: %zd\n",
+                              PFID(lu_object_fid(&obj->co_lu)),
+                              queue->c2_qin.pl_nr, rc);
+                       if (rc == 0)
+                               rc = -EIO;
+               }
        }
 
-#if defined(HAVE_DIRECTIO_ITER) || defined(HAVE_IOV_ITER_RW)
-       kvfree(pages);
-#else
-       OBD_FREE_LARGE(pages, npages * sizeof(*pages));
-#endif
+       cl_2queue_discard(env, io, queue);
+       cl_2queue_disown(env, io, queue);
+       cl_2queue_fini(env, queue);
+       RETURN(rc);
 }
 
 #ifdef KMALLOC_MAX_SIZE
@@ -308,37 +440,23 @@ static void ll_free_user_pages(struct page **pages, int npages, int do_dirty)
 #define MAX_DIO_SIZE ((MAX_MALLOC / sizeof(struct brw_page) * PAGE_SIZE) & \
                      ~(DT_MAX_BRW_SIZE - 1))
 
-#ifndef HAVE_IOV_ITER_RW
-# define iov_iter_rw(iter)     rw
-#endif
-
-#if defined(HAVE_DIRECTIO_ITER) || defined(HAVE_IOV_ITER_RW)
 static ssize_t
-ll_direct_IO(
-# ifndef HAVE_IOV_ITER_RW
-            int rw,
-# endif
-            struct kiocb *iocb, struct iov_iter *iter
-# ifndef HAVE_DIRECTIO_2ARGS
-            , loff_t file_offset
-# endif
-            )
+ll_direct_IO_impl(struct kiocb *iocb, struct iov_iter *iter, int rw)
 {
-#ifdef HAVE_DIRECTIO_2ARGS
-       loff_t file_offset = iocb->ki_pos;
-#endif
        struct ll_cl_context *lcc;
        const struct lu_env *env;
        struct cl_io *io;
        struct file *file = iocb->ki_filp;
        struct inode *inode = file->f_mapping->host;
-       ssize_t count = iov_iter_count(iter);
+       struct cl_dio_aio *aio;
+       size_t count = iov_iter_count(iter);
        ssize_t tot_bytes = 0, result = 0;
-       size_t size = MAX_DIO_SIZE;
+       loff_t file_offset = iocb->ki_pos;
 
        /* Check EOF by ourselves */
-       if (iov_iter_rw(iter) == READ && file_offset >= i_size_read(inode))
+       if (rw == READ && file_offset >= i_size_read(inode))
                return 0;
+
        /* FIXME: io smaller than PAGE_SIZE is broken on ia64 ??? */
        if ((file_offset & ~PAGE_MASK) || (count & ~PAGE_MASK))
                return -EINVAL;
@@ -350,7 +468,7 @@ ll_direct_IO(
               MAX_DIO_SIZE >> PAGE_SHIFT);
 
        /* Check that all user buffers are aligned as well */
-       if (iov_iter_alignment(iter) & ~PAGE_MASK)
+       if (ll_iov_iter_alignment(iter) & ~PAGE_MASK)
                return -EINVAL;
 
        lcc = ll_cl_find(file);
@@ -362,19 +480,23 @@ ll_direct_IO(
        io = lcc->lcc_io;
        LASSERT(io != NULL);
 
+       aio = ll_aio_alloc(iocb);
+       if (!aio)
+               RETURN(-ENOMEM);
+
        /* 0. Need locking between buffered and direct access. and race with
         *    size changing by concurrent truncates and writes.
         * 1. Need inode mutex to operate transient pages.
         */
-       if (iov_iter_rw(iter) == READ)
+       if (rw == READ)
                inode_lock(inode);
 
        while (iov_iter_count(iter)) {
+               struct ll_dio_pages pvec = { .ldp_aio = aio };
                struct page **pages;
-               size_t offs;
 
-               count = min_t(size_t, iov_iter_count(iter), size);
-               if (iov_iter_rw(iter) == READ) {
+               count = min_t(size_t, iov_iter_count(iter), MAX_DIO_SIZE);
+               if (rw == READ) {
                        if (file_offset >= i_size_read(inode))
                                break;
 
@@ -382,194 +504,91 @@ ll_direct_IO(
                                count = i_size_read(inode) - file_offset;
                }
 
-               result = iov_iter_get_pages_alloc(iter, &pages, count, &offs);
-               if (likely(result > 0)) {
-                       int n = DIV_ROUND_UP(result + offs, PAGE_SIZE);
+               result = ll_get_user_pages(rw, iter, &pages,
+                                          &pvec.ldp_count, count);
+               if (unlikely(result <= 0))
+                       GOTO(out, result);
 
-                       result = ll_direct_IO_seg(env, io, iov_iter_rw(iter),
-                                                 inode, result, file_offset,
-                                                 pages, n);
-                       ll_free_user_pages(pages, n,
-                                          iov_iter_rw(iter) == READ);
+               count = result;
+               pvec.ldp_file_offset = file_offset;
+               pvec.ldp_pages = pages;
 
-               }
-               if (unlikely(result <= 0)) {
-                       /* If we can't allocate a large enough buffer
-                        * for the request, shrink it to a smaller
-                        * PAGE_SIZE multiple and try again.
-                        * We should always be able to kmalloc for a
-                        * page worth of page pointers = 4MB on i386. */
-                       if (result == -ENOMEM &&
-                           size > (PAGE_SIZE / sizeof(*pages)) *
-                                   PAGE_SIZE) {
-                               size = ((((size / 2) - 1) |
-                                       ~PAGE_MASK) + 1) & PAGE_MASK;
-                               CDEBUG(D_VFSTRACE, "DIO size now %zu\n",
-                                      size);
-                               continue;
-                       }
+               result = ll_direct_rw_pages(env, io, count,
+                                           rw, inode, &pvec);
+               ll_free_user_pages(pages, pvec.ldp_count);
 
+               if (unlikely(result < 0))
                        GOTO(out, result);
-               }
 
-               iov_iter_advance(iter, result);
-               tot_bytes += result;
-               file_offset += result;
+               iov_iter_advance(iter, count);
+               tot_bytes += count;
+               file_offset += count;
        }
-out:
-       if (iov_iter_rw(iter) == READ)
-               inode_unlock(inode);
 
-       if (tot_bytes > 0) {
-               struct vvp_io *vio = vvp_env_io(env);
+out:
+       aio->cda_bytes = tot_bytes;
+       cl_sync_io_note(env, &aio->cda_sync, result);
 
-               /* no commit async for direct IO */
-               vio->u.write.vui_written += tot_bytes;
-       }
+       if (is_sync_kiocb(iocb)) {
+               ssize_t rc2;
 
-       return tot_bytes ? : result;
-}
-#else /* !HAVE_DIRECTIO_ITER && !HAVE_IOV_ITER_RW */
+               rc2 = cl_sync_io_wait(env, &aio->cda_sync, 0);
+               if (result == 0 && rc2)
+                       result = rc2;
 
-static inline int ll_get_user_pages(int rw, unsigned long user_addr,
-                                   size_t size, struct page ***pages,
-                                   int *max_pages)
-{
-       int result = -ENOMEM;
+               if (result == 0) {
+                       struct vvp_io *vio = vvp_env_io(env);
+                       /* no commit async for direct IO */
+                       vio->u.write.vui_written += tot_bytes;
+                       result = tot_bytes;
+               }
+               OBD_FREE_PTR(aio);
 
-       /* set an arbitrary limit to prevent arithmetic overflow */
-       if (size > MAX_DIRECTIO_SIZE) {
-               *pages = NULL;
-               return -EFBIG;
+       } else {
+               result = -EIOCBQUEUED;
        }
 
-       *max_pages = (user_addr + size + PAGE_SIZE - 1) >>
-                     PAGE_SHIFT;
-       *max_pages -= user_addr >> PAGE_SHIFT;
-
-       OBD_ALLOC_LARGE(*pages, *max_pages * sizeof(**pages));
-       if (*pages) {
-               down_read(&current->mm->mmap_sem);
-               result = get_user_pages(current, current->mm, user_addr,
-                                       *max_pages, (rw == READ), 0, *pages,
-                                       NULL);
-               up_read(&current->mm->mmap_sem);
-               if (unlikely(result <= 0))
-                       OBD_FREE_LARGE(*pages, *max_pages * sizeof(**pages));
-       }
+       if (rw == READ)
+               inode_unlock(inode);
 
        return result;
 }
 
-static ssize_t
-ll_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
-            loff_t file_offset, unsigned long nr_segs)
+#if defined(HAVE_DIO_ITER)
+static ssize_t ll_direct_IO(
+#ifndef HAVE_IOV_ITER_RW
+            int rw,
+#endif
+            struct kiocb *iocb, struct iov_iter *iter
+#ifndef HAVE_DIRECTIO_2ARGS
+            , loff_t file_offset
+#endif
+            )
 {
-       struct ll_cl_context *lcc;
-       const struct lu_env *env;
-       struct cl_io *io;
-       struct file *file = iocb->ki_filp;
-       struct inode *inode = file->f_mapping->host;
-       ssize_t count = iov_length(iov, nr_segs);
-       ssize_t tot_bytes = 0, result = 0;
-       unsigned long seg = 0;
-       size_t size = MAX_DIO_SIZE;
-       ENTRY;
-
-        /* FIXME: io smaller than PAGE_SIZE is broken on ia64 ??? */
-       if ((file_offset & ~PAGE_MASK) || (count & ~PAGE_MASK))
-                RETURN(-EINVAL);
+       int nrw;
 
-       CDEBUG(D_VFSTRACE, "VFS Op:inode="DFID"(%p), size=%zd (max %lu), "
-              "offset=%lld=%llx, pages %zd (max %lu)\n",
-              PFID(ll_inode2fid(inode)), inode, count, MAX_DIO_SIZE,
-              file_offset, file_offset, count >> PAGE_SHIFT,
-              MAX_DIO_SIZE >> PAGE_SHIFT);
-
-        /* Check that all user buffers are aligned as well */
-        for (seg = 0; seg < nr_segs; seg++) {
-               if (((unsigned long)iov[seg].iov_base & ~PAGE_MASK) ||
-                   (iov[seg].iov_len & ~PAGE_MASK))
-                        RETURN(-EINVAL);
-        }
-
-       lcc = ll_cl_find(file);
-       if (lcc == NULL)
-               RETURN(-EIO);
+#ifndef HAVE_IOV_ITER_RW
+       nrw = rw;
+#else
+       nrw = iov_iter_rw(iter);
+#endif
 
-       env = lcc->lcc_env;
-       LASSERT(!IS_ERR(env));
-       io = lcc->lcc_io;
-       LASSERT(io != NULL);
+       return ll_direct_IO_impl(iocb, iter, nrw);
+}
 
-        for (seg = 0; seg < nr_segs; seg++) {
-               size_t iov_left = iov[seg].iov_len;
-                unsigned long user_addr = (unsigned long)iov[seg].iov_base;
-
-                if (rw == READ) {
-                        if (file_offset >= i_size_read(inode))
-                                break;
-                        if (file_offset + iov_left > i_size_read(inode))
-                                iov_left = i_size_read(inode) - file_offset;
-                }
-
-                while (iov_left > 0) {
-                        struct page **pages;
-                        int page_count, max_pages = 0;
-                       size_t bytes;
-
-                        bytes = min(size, iov_left);
-                        page_count = ll_get_user_pages(rw, user_addr, bytes,
-                                                       &pages, &max_pages);
-                        if (likely(page_count > 0)) {
-                                if (unlikely(page_count <  max_pages))
-                                       bytes = page_count << PAGE_SHIFT;
-                               result = ll_direct_IO_seg(env, io, rw, inode,
-                                                         bytes, file_offset,
-                                                         pages, page_count);
-                                ll_free_user_pages(pages, max_pages, rw==READ);
-                        } else if (page_count == 0) {
-                                GOTO(out, result = -EFAULT);
-                        } else {
-                                result = page_count;
-                        }
-                        if (unlikely(result <= 0)) {
-                                /* If we can't allocate a large enough buffer
-                                 * for the request, shrink it to a smaller
-                                 * PAGE_SIZE multiple and try again.
-                                 * We should always be able to kmalloc for a
-                                 * page worth of page pointers = 4MB on i386. */
-                                if (result == -ENOMEM &&
-                                   size > (PAGE_SIZE / sizeof(*pages)) *
-                                          PAGE_SIZE) {
-                                        size = ((((size / 2) - 1) |
-                                                ~PAGE_MASK) + 1) &
-                                               PAGE_MASK;
-                                       CDEBUG(D_VFSTRACE, "DIO size now %zu\n",
-                                               size);
-                                        continue;
-                                }
-
-                                GOTO(out, result);
-                        }
-
-                        tot_bytes += result;
-                        file_offset += result;
-                        iov_left -= result;
-                        user_addr += result;
-                }
-        }
-out:
-        if (tot_bytes > 0) {
-               struct vvp_io *vio = vvp_env_io(env);
+#else /* !defined(HAVE_DIO_ITER) */
 
-               /* no commit async for direct IO */
-               vio->u.write.vui_written += tot_bytes;
-       }
+static ssize_t
+ll_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
+            loff_t file_offset, unsigned long nr_segs)
+{
+       struct iov_iter iter;
 
-       RETURN(tot_bytes ? tot_bytes : result);
+       iov_iter_init(&iter, iov, nr_segs, iov_length(iov, nr_segs), 0);
+       return ll_direct_IO_impl(iocb, &iter, rw);
 }
-#endif /* HAVE_DIRECTIO_ITER || HAVE_IOV_ITER_RW */
+
+#endif /* !defined(HAVE_DIO_ITER) */
 
 /**
  * Prepare partially written-to page for a write.