Revert "Merge branch 'odirect'"

This reverts ccf01ef7aa9c6c293a1c64c27331a2ce227916ec commit.

No idea how git managed this one: when I asked it to merge the odirect
topic branch it actually generated a patch which reverted the change.

Reverting the 'merge' will once again reveal Chuck's recent NFS/O_DIRECT
work to the world.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 201 insertions, 234 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 8ca9707be6c9..9ae7b6f6bf30 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -68,25 +68,19 @@ struct nfs_direct_req {
         struct kref             kref;           /* release manager */
 
         /* I/O parameters */
-        struct list_head        list,           /* nfs_read/write_data structs */
-                                rewrite_list;   /* saved nfs_write_data structs */
         struct nfs_open_context *ctx;           /* file open context info */
         struct kiocb *          iocb;           /* controlling i/o request */
         struct inode *          inode;          /* target file of i/o */
-        unsigned long           user_addr;      /* location of user's buffer */
-        size_t                  user_count;     /* total bytes to move */
-        loff_t                  pos;            /* starting offset in file */
-        struct page **          pages;          /* pages in our buffer */
-        unsigned int            npages;         /* count of pages */
 
         /* completion state */
+        atomic_t                io_count;       /* i/os we're waiting for */
         spinlock_t              lock;           /* protect completion state */
-        int                     outstanding;    /* i/os we're waiting for */
         ssize_t                 count,          /* bytes actually processed */
                                 error;          /* any reported error */
         struct completion       completion;     /* wait for i/o completion */
 
         /* commit state */
+        struct list_head        rewrite_list;   /* saved nfs_write_data structs */
         struct nfs_write_data * commit_data;    /* special write_data for commits */
         int                     flags;
 #define NFS_ODIRECT_DO_COMMIT           (1)     /* an unstable reply was received */
@@ -94,8 +88,37 @@ struct nfs_direct_req {
         struct nfs_writeverf    verf;           /* unstable write verifier */
 };
 
-static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, int sync);
 static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode);
+static const struct rpc_call_ops nfs_write_direct_ops;
+
+static inline void get_dreq(struct nfs_direct_req *dreq)
+{
+        atomic_inc(&dreq->io_count);
+}
+
+static inline int put_dreq(struct nfs_direct_req *dreq)
+{
+        return atomic_dec_and_test(&dreq->io_count);
+}
+
+/*
+ * "size" is never larger than rsize or wsize.
+ */
+static inline int nfs_direct_count_pages(unsigned long user_addr, size_t size)
+{
+        int page_count;
+
+        page_count = (user_addr + size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+        page_count -= user_addr >> PAGE_SHIFT;
+        BUG_ON(page_count < 0);
+
+        return page_count;
+}
+
+static inline unsigned int nfs_max_pages(unsigned int size)
+{
+        return (size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+}
 
 /**
  * nfs_direct_IO - NFS address space operation for direct I/O
@@ -119,50 +142,21 @@ ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_
         return -EINVAL;
 }
 
-static void nfs_free_user_pages(struct page **pages, int npages, int do_dirty)
+static void nfs_direct_dirty_pages(struct page **pages, int npages)
 {
         int i;
         for (i = 0; i < npages; i++) {
                 struct page *page = pages[i];
-                if (do_dirty && !PageCompound(page))
+                if (!PageCompound(page))
                         set_page_dirty_lock(page);
-                page_cache_release(page);
         }
-        kfree(pages);
 }
 
-static inline int nfs_get_user_pages(int rw, unsigned long user_addr, size_t size, struct page ***pages)
+static void nfs_direct_release_pages(struct page **pages, int npages)
 {
-        int result = -ENOMEM;
-        unsigned long page_count;
-        size_t array_size;
-
-        page_count = (user_addr + size + PAGE_SIZE - 1) >> PAGE_SHIFT;
-        page_count -= user_addr >> PAGE_SHIFT;
-
-        array_size = (page_count * sizeof(struct page *));
-        *pages = kmalloc(array_size, GFP_KERNEL);
-        if (*pages) {
-                down_read(&current->mm->mmap_sem);
-                result = get_user_pages(current, current->mm, user_addr,
-                                        page_count, (rw == READ), 0,
-                                        *pages, NULL);
-                up_read(&current->mm->mmap_sem);
-                if (result != page_count) {
-                        /*
-                         * If we got fewer pages than expected from
-                         * get_user_pages(), the user buffer runs off the
-                         * end of a mapping; return EFAULT.
-                         */
-                        if (result >= 0) {
-                                nfs_free_user_pages(*pages, result, 0);
-                                result = -EFAULT;
-                        } else
-                                kfree(*pages);
-                        *pages = NULL;
-                }
-        }
-        return result;
+        int i;
+        for (i = 0; i < npages; i++)
+                page_cache_release(pages[i]);
 }
 
 static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
@@ -174,13 +168,13 @@ static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
                 return NULL;
 
         kref_init(&dreq->kref);
+        kref_get(&dreq->kref);
         init_completion(&dreq->completion);
-        INIT_LIST_HEAD(&dreq->list);
         INIT_LIST_HEAD(&dreq->rewrite_list);
         dreq->iocb = NULL;
         dreq->ctx = NULL;
         spin_lock_init(&dreq->lock);
-        dreq->outstanding = 0;
+        atomic_set(&dreq->io_count, 0);
         dreq->count = 0;
         dreq->error = 0;
         dreq->flags = 0;
@@ -221,18 +215,11 @@ out:
 }
 
 /*
- * We must hold a reference to all the pages in this direct read request
- * until the RPCs complete.  This could be long *after* we are woken up in
- * nfs_direct_wait (for instance, if someone hits ^C on a slow server).
- *
- * In addition, synchronous I/O uses a stack-allocated iocb.  Thus we
- * can't trust the iocb is still valid here if this is a synchronous
- * request.  If the waiter is woken prematurely, the iocb is long gone.
+ * Synchronous I/O uses a stack-allocated iocb.  Thus we can't trust
+ * the iocb is still valid here if this is a synchronous request.
  */
 static void nfs_direct_complete(struct nfs_direct_req *dreq)
 {
-        nfs_free_user_pages(dreq->pages, dreq->npages, 1);
-
         if (dreq->iocb) {
                 long res = (long) dreq->error;
                 if (!res)
@@ -245,48 +232,10 @@ static void nfs_direct_complete(struct nfs_direct_req *dreq)
 }
 
 /*
- * Note we also set the number of requests we have in the dreq when we are
- * done.  This prevents races with I/O completion so we will always wait
- * until all requests have been dispatched and completed.
+ * We must hold a reference to all the pages in this direct read request
+ * until the RPCs complete.  This could be long *after* we are woken up in
+ * nfs_direct_wait (for instance, if someone hits ^C on a slow server).
  */
-static struct nfs_direct_req *nfs_direct_read_alloc(size_t nbytes, size_t rsize)
-{
-        struct list_head *list;
-        struct nfs_direct_req *dreq;
-        unsigned int rpages = (rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-
-        dreq = nfs_direct_req_alloc();
-        if (!dreq)
-                return NULL;
-
-        list = &dreq->list;
-        for(;;) {
-                struct nfs_read_data *data = nfs_readdata_alloc(rpages);
-
-                if (unlikely(!data)) {
-                        while (!list_empty(list)) {
-                                data = list_entry(list->next,
-                                                  struct nfs_read_data, pages);
-                                list_del(&data->pages);
-                                nfs_readdata_free(data);
-                        }
-                        kref_put(&dreq->kref, nfs_direct_req_release);
-                        return NULL;
-                }
-
-                INIT_LIST_HEAD(&data->pages);
-                list_add(&data->pages, list);
-
-                data->req = (struct nfs_page *) dreq;
-                dreq->outstanding++;
-                if (nbytes <= rsize)
-                        break;
-                nbytes -= rsize;
-        }
-        kref_get(&dreq->kref);
-        return dreq;
-}
-
 static void nfs_direct_read_result(struct rpc_task *task, void *calldata)
 {
         struct nfs_read_data *data = calldata;
@@ -295,6 +244,9 @@ static void nfs_direct_read_result(struct rpc_task *task, void *calldata)
         if (nfs_readpage_result(task, data) != 0)
                 return;
 
+        nfs_direct_dirty_pages(data->pagevec, data->npages);
+        nfs_direct_release_pages(data->pagevec, data->npages);
+
         spin_lock(&dreq->lock);
 
         if (likely(task->tk_status >= 0))
@@ -302,13 +254,10 @@ static void nfs_direct_read_result(struct rpc_task *task, void *calldata)
         else
                 dreq->error = task->tk_status;
 
-        if (--dreq->outstanding) {
-                spin_unlock(&dreq->lock);
-                return;
-        }
-
         spin_unlock(&dreq->lock);
-        nfs_direct_complete(dreq);
+
+        if (put_dreq(dreq))
+                nfs_direct_complete(dreq);
 }
 
 static const struct rpc_call_ops nfs_read_direct_ops = {
@@ -317,41 +266,60 @@ static const struct rpc_call_ops nfs_read_direct_ops = {
 };
 
 /*
- * For each nfs_read_data struct that was allocated on the list, dispatch
- * an NFS READ operation
+ * For each rsize'd chunk of the user's buffer, dispatch an NFS READ
+ * operation.  If nfs_readdata_alloc() or get_user_pages() fails,
+ * bail and stop sending more reads.  Read length accounting is
+ * handled automatically by nfs_direct_read_result().  Otherwise, if
+ * no requests have been sent, just return an error.
  */
-static void nfs_direct_read_schedule(struct nfs_direct_req *dreq)
+static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos)
 {
         struct nfs_open_context *ctx = dreq->ctx;
         struct inode *inode = ctx->dentry->d_inode;
-        struct list_head *list = &dreq->list;
-        struct page **pages = dreq->pages;
-        size_t count = dreq->user_count;
-        loff_t pos = dreq->pos;
         size_t rsize = NFS_SERVER(inode)->rsize;
-        unsigned int curpage, pgbase;
+        unsigned int rpages = nfs_max_pages(rsize);
+        unsigned int pgbase;
+        int result;
+        ssize_t started = 0;
+
+        get_dreq(dreq);
 
-        curpage = 0;
-        pgbase = dreq->user_addr & ~PAGE_MASK;
+        pgbase = user_addr & ~PAGE_MASK;
         do {
                 struct nfs_read_data *data;
                 size_t bytes;
 
+                result = -ENOMEM;
+                data = nfs_readdata_alloc(rpages);
+                if (unlikely(!data))
+                        break;
+
                 bytes = rsize;
                 if (count < rsize)
                         bytes = count;
 
-                BUG_ON(list_empty(list));
-                data = list_entry(list->next, struct nfs_read_data, pages);
-                list_del_init(&data->pages);
+                data->npages = nfs_direct_count_pages(user_addr, bytes);
+                down_read(&current->mm->mmap_sem);
+                result = get_user_pages(current, current->mm, user_addr,
+                                        data->npages, 1, 0, data->pagevec, NULL);
+                up_read(&current->mm->mmap_sem);
+                if (unlikely(result < data->npages)) {
+                        if (result > 0)
+                                nfs_direct_release_pages(data->pagevec, result);
+                        nfs_readdata_release(data);
+                        break;
+                }
+
+                get_dreq(dreq);
 
+                data->req = (struct nfs_page *) dreq;
                 data->inode = inode;
                 data->cred = ctx->cred;
                 data->args.fh = NFS_FH(inode);
                 data->args.context = ctx;
                 data->args.offset = pos;
                 data->args.pgbase = pgbase;
-                data->args.pages = &pages[curpage];
+                data->args.pages = data->pagevec;
                 data->args.count = bytes;
                 data->res.fattr = &data->fattr;
                 data->res.eof = 0;
@@ -374,33 +342,35 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq)
                                 bytes,
                                 (unsigned long long)data->args.offset);
 
+                started += bytes;
+                user_addr += bytes;
                 pos += bytes;
                 pgbase += bytes;
-                curpage += pgbase >> PAGE_SHIFT;
                 pgbase &= ~PAGE_MASK;
 
                 count -= bytes;
         } while (count != 0);
-        BUG_ON(!list_empty(list));
+
+        if (put_dreq(dreq))
+                nfs_direct_complete(dreq);
+
+        if (started)
+                return 0;
+        return result < 0 ? (ssize_t) result : -EFAULT;
 }
 
-static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos, struct page **pages, unsigned int nr_pages)
+static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos)
 {
-        ssize_t result;
+        ssize_t result = 0;
         sigset_t oldset;
         struct inode *inode = iocb->ki_filp->f_mapping->host;
         struct rpc_clnt *clnt = NFS_CLIENT(inode);
         struct nfs_direct_req *dreq;
 
-        dreq = nfs_direct_read_alloc(count, NFS_SERVER(inode)->rsize);
+        dreq = nfs_direct_req_alloc();
         if (!dreq)
                 return -ENOMEM;
 
-        dreq->user_addr = user_addr;
-        dreq->user_count = count;
-        dreq->pos = pos;
-        dreq->pages = pages;
-        dreq->npages = nr_pages;
         dreq->inode = inode;
         dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data);
         if (!is_sync_kiocb(iocb))
@@ -408,8 +378,9 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size
 
         nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count);
         rpc_clnt_sigmask(clnt, &oldset);
-        nfs_direct_read_schedule(dreq);
-        result = nfs_direct_wait(dreq);
+        result = nfs_direct_read_schedule(dreq, user_addr, count, pos);
+        if (!result)
+                result = nfs_direct_wait(dreq);
         rpc_clnt_sigunmask(clnt, &oldset);
 
         return result;
@@ -417,10 +388,10 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size
 
 static void nfs_direct_free_writedata(struct nfs_direct_req *dreq)
 {
-        list_splice_init(&dreq->rewrite_list, &dreq->list);
-        while (!list_empty(&dreq->list)) {
-                struct nfs_write_data *data = list_entry(dreq->list.next, struct nfs_write_data, pages);
+        while (!list_empty(&dreq->rewrite_list)) {
+                struct nfs_write_data *data = list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages);
                 list_del(&data->pages);
+                nfs_direct_release_pages(data->pagevec, data->npages);
                 nfs_writedata_release(data);
         }
 }
@@ -428,14 +399,51 @@ static void nfs_direct_free_writedata(struct nfs_direct_req *dreq)
 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
 static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
 {
-        struct list_head *pos;
+        struct inode *inode = dreq->inode;
+        struct list_head *p;
+        struct nfs_write_data *data;
 
-        list_splice_init(&dreq->rewrite_list, &dreq->list);
-        list_for_each(pos, &dreq->list)
-                dreq->outstanding++;
         dreq->count = 0;
+        get_dreq(dreq);
+
+        list_for_each(p, &dreq->rewrite_list) {
+                data = list_entry(p, struct nfs_write_data, pages);
+
+                get_dreq(dreq);
+
+                /*
+                 * Reset data->res.
+                 */
+                nfs_fattr_init(&data->fattr);
+                data->res.count = data->args.count;
+                memset(&data->verf, 0, sizeof(data->verf));
+
+                /*
+                 * Reuse data->task; data->args should not have changed
+                 * since the original request was sent.
+                 */
+                rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC,
+                                &nfs_write_direct_ops, data);
+                NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE);
+
+                data->task.tk_priority = RPC_PRIORITY_NORMAL;
+                data->task.tk_cookie = (unsigned long) inode;
+
+                /*
+                 * We're called via an RPC callback, so BKL is already held.
+                 */
+                rpc_execute(&data->task);
+
+                dprintk("NFS: %5u rescheduled direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n",
+                                data->task.tk_pid,
+                                inode->i_sb->s_id,
+                                (long long)NFS_FILEID(inode),
+                                data->args.count,
+                                (unsigned long long)data->args.offset);
+        }
 
-        nfs_direct_write_schedule(dreq, FLUSH_STABLE);
+        if (put_dreq(dreq))
+                nfs_direct_write_complete(dreq, inode);
 }
 
 static void nfs_direct_commit_result(struct rpc_task *task, void *calldata)
@@ -472,8 +480,8 @@ static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq)
         data->cred = dreq->ctx->cred;
 
         data->args.fh = NFS_FH(data->inode);
-        data->args.offset = dreq->pos;
-        data->args.count = dreq->user_count;
+        data->args.offset = 0;
+        data->args.count = 0;
         data->res.count = 0;
         data->res.fattr = &data->fattr;
         data->res.verf = &data->verf;
@@ -535,47 +543,6 @@ static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode
 }
 #endif
 
-static struct nfs_direct_req *nfs_direct_write_alloc(size_t nbytes, size_t wsize)
-{
-        struct list_head *list;
-        struct nfs_direct_req *dreq;
-        unsigned int wpages = (wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-
-        dreq = nfs_direct_req_alloc();
-        if (!dreq)
-                return NULL;
-
-        list = &dreq->list;
-        for(;;) {
-                struct nfs_write_data *data = nfs_writedata_alloc(wpages);
-
-                if (unlikely(!data)) {
-                        while (!list_empty(list)) {
-                                data = list_entry(list->next,
-                                                  struct nfs_write_data, pages);
-                                list_del(&data->pages);
-                                nfs_writedata_free(data);
-                        }
-                        kref_put(&dreq->kref, nfs_direct_req_release);
-                        return NULL;
-                }
-
-                INIT_LIST_HEAD(&data->pages);
-                list_add(&data->pages, list);
-
-                data->req = (struct nfs_page *) dreq;
-                dreq->outstanding++;
-                if (nbytes <= wsize)
-                        break;
-                nbytes -= wsize;
-        }
-
-        nfs_alloc_commit_data(dreq);
-
-        kref_get(&dreq->kref);
-        return dreq;
-}
-
 static void nfs_direct_write_result(struct rpc_task *task, void *calldata)
 {
         struct nfs_write_data *data = calldata;
@@ -605,8 +572,6 @@ static void nfs_direct_write_result(struct rpc_task *task, void *calldata)
                                 }
                 }
         }
-        /* In case we have to resend */
-        data->args.stable = NFS_FILE_SYNC;
 
         spin_unlock(&dreq->lock);
 }
@@ -620,14 +585,8 @@ static void nfs_direct_write_release(void *calldata)
         struct nfs_write_data *data = calldata;
         struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req;
 
-        spin_lock(&dreq->lock);
-        if (--dreq->outstanding) {
-                spin_unlock(&dreq->lock);
-                return;
-        }
-        spin_unlock(&dreq->lock);
-
-        nfs_direct_write_complete(dreq, data->inode);
+        if (put_dreq(dreq))
+                nfs_direct_write_complete(dreq, data->inode);
 }
 
 static const struct rpc_call_ops nfs_write_direct_ops = {
@@ -636,41 +595,62 @@ static const struct rpc_call_ops nfs_write_direct_ops = {
 };
 
 /*
- * For each nfs_write_data struct that was allocated on the list, dispatch
- * an NFS WRITE operation
+ * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE
+ * operation.  If nfs_writedata_alloc() or get_user_pages() fails,
+ * bail and stop sending more writes.  Write length accounting is
+ * handled automatically by nfs_direct_write_result().  Otherwise, if
+ * no requests have been sent, just return an error.
  */
-static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, int sync)
+static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos, int sync)
 {
         struct nfs_open_context *ctx = dreq->ctx;
         struct inode *inode = ctx->dentry->d_inode;
-        struct list_head *list = &dreq->list;
-        struct page **pages = dreq->pages;
-        size_t count = dreq->user_count;
-        loff_t pos = dreq->pos;
         size_t wsize = NFS_SERVER(inode)->wsize;
-        unsigned int curpage, pgbase;
+        unsigned int wpages = nfs_max_pages(wsize);
+        unsigned int pgbase;
+        int result;
+        ssize_t started = 0;
 
-        curpage = 0;
-        pgbase = dreq->user_addr & ~PAGE_MASK;
+        get_dreq(dreq);
+
+        pgbase = user_addr & ~PAGE_MASK;
         do {
                 struct nfs_write_data *data;
                 size_t bytes;
 
+                result = -ENOMEM;
+                data = nfs_writedata_alloc(wpages);
+                if (unlikely(!data))
+                        break;
+
                 bytes = wsize;
                 if (count < wsize)
                         bytes = count;
 
-                BUG_ON(list_empty(list));
-                data = list_entry(list->next, struct nfs_write_data, pages);
+                data->npages = nfs_direct_count_pages(user_addr, bytes);
+                down_read(&current->mm->mmap_sem);
+                result = get_user_pages(current, current->mm, user_addr,
+                                        data->npages, 0, 0, data->pagevec, NULL);
+                up_read(&current->mm->mmap_sem);
+                if (unlikely(result < data->npages)) {
+                        if (result > 0)
+                                nfs_direct_release_pages(data->pagevec, result);
+                        nfs_writedata_release(data);
+                        break;
+                }
+
+                get_dreq(dreq);
+
                 list_move_tail(&data->pages, &dreq->rewrite_list);
 
+                data->req = (struct nfs_page *) dreq;
                 data->inode = inode;
                 data->cred = ctx->cred;
                 data->args.fh = NFS_FH(inode);
                 data->args.context = ctx;
                 data->args.offset = pos;
                 data->args.pgbase = pgbase;
-                data->args.pages = &pages[curpage];
+                data->args.pages = data->pagevec;
                 data->args.count = bytes;
                 data->res.fattr = &data->fattr;
                 data->res.count = bytes;
@@ -694,19 +674,26 @@ static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, int sync)
                                 bytes,
                                 (unsigned long long)data->args.offset);
 
+                started += bytes;
+                user_addr += bytes;
                 pos += bytes;
                 pgbase += bytes;
-                curpage += pgbase >> PAGE_SHIFT;
                 pgbase &= ~PAGE_MASK;
 
                 count -= bytes;
         } while (count != 0);
-        BUG_ON(!list_empty(list));
+
+        if (put_dreq(dreq))
+                nfs_direct_write_complete(dreq, inode);
+
+        if (started)
+                return 0;
+        return result < 0 ? (ssize_t) result : -EFAULT;
 }
 
-static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos, struct page **pages, int nr_pages)
+static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos)
 {
-        ssize_t result;
+        ssize_t result = 0;
         sigset_t oldset;
         struct inode *inode = iocb->ki_filp->f_mapping->host;
         struct rpc_clnt *clnt = NFS_CLIENT(inode);
@@ -714,17 +701,14 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, siz
         size_t wsize = NFS_SERVER(inode)->wsize;
         int sync = 0;
 
-        dreq = nfs_direct_write_alloc(count, wsize);
+        dreq = nfs_direct_req_alloc();
         if (!dreq)
                 return -ENOMEM;
+        nfs_alloc_commit_data(dreq);
+
         if (dreq->commit_data == NULL || count < wsize)
                 sync = FLUSH_STABLE;
 
-        dreq->user_addr = user_addr;
-        dreq->user_count = count;
-        dreq->pos = pos;
-        dreq->pages = pages;
-        dreq->npages = nr_pages;
         dreq->inode = inode;
         dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data);
         if (!is_sync_kiocb(iocb))
@@ -735,8 +719,9 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, siz
         nfs_begin_data_update(inode);
 
         rpc_clnt_sigmask(clnt, &oldset);
-        nfs_direct_write_schedule(dreq, sync);
-        result = nfs_direct_wait(dreq);
+        result = nfs_direct_write_schedule(dreq, user_addr, count, pos, sync);
+        if (!result)
+                result = nfs_direct_wait(dreq);
         rpc_clnt_sigunmask(clnt, &oldset);
 
         return result;
@@ -766,8 +751,6 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, siz
 ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count, loff_t pos)
 {
         ssize_t retval = -EINVAL;
-        int page_count;
-        struct page **pages;
         struct file *file = iocb->ki_filp;
         struct address_space *mapping = file->f_mapping;
 
@@ -789,14 +772,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count,
         if (retval)
                 goto out;
 
-        retval = nfs_get_user_pages(READ, (unsigned long) buf,
-                                                count, &pages);
-        if (retval < 0)
-                goto out;
-        page_count = retval;
-
-        retval = nfs_direct_read(iocb, (unsigned long) buf, count, pos,
-                                                pages, page_count);
+        retval = nfs_direct_read(iocb, (unsigned long) buf, count, pos);
         if (retval > 0)
                 iocb->ki_pos = pos + retval;
 
@@ -832,8 +808,6 @@ out:
 ssize_t nfs_file_direct_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos)
 {
         ssize_t retval;
-        int page_count;
-        struct page **pages;
         struct file *file = iocb->ki_filp;
         struct address_space *mapping = file->f_mapping;
 
@@ -861,14 +835,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, const char __user *buf, size_t
         if (retval)
                 goto out;
 
-        retval = nfs_get_user_pages(WRITE, (unsigned long) buf,
-                                                count, &pages);
-        if (retval < 0)
-                goto out;
-        page_count = retval;
-
-        retval = nfs_direct_write(iocb, (unsigned long) buf, count,
-                                        pos, pages, page_count);
+        retval = nfs_direct_write(iocb, (unsigned long) buf, count, pos);
 
         /*
          * XXX: nfs_end_data_update() already ensures this file's