Revert "Merge branch 'odirect'"

	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 */

	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

	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)

		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;

}

/*

 * 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)

}

/*

 * 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;

	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))

	else

		dreq->error = task->tk_status;

	if (--dreq->outstanding) {

	spin_unlock(&dreq->lock);

		return;

	}

	spin_unlock(&dreq->lock);

	if (put_dreq(dreq))

		nfs_direct_complete(dreq);

}

};

/*

 * 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;

	curpage = 0;

	pgbase = dreq->user_addr & ~PAGE_MASK;

	get_dreq(dreq);

	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;

				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))

	nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count);

	rpc_clnt_sigmask(clnt, &oldset);

	nfs_direct_read_schedule(dreq);

	result = nfs_direct_read_schedule(dreq, user_addr, count, pos);

	if (!result)

		result = nfs_direct_wait(dreq);

	rpc_clnt_sigunmask(clnt, &oldset);

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);

	}

}

#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);

	nfs_direct_write_schedule(dreq, FLUSH_STABLE);

		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);

	}

	if (put_dreq(dreq))

		nfs_direct_write_complete(dreq, inode);

}

static void nfs_direct_commit_result(struct rpc_task *task, void *calldata)

	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;

}

#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;

				}

		}

	}

	/* In case we have to resend */

	data->args.stable = NFS_FILE_SYNC;

	spin_unlock(&dreq->lock);

}

	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);

	if (put_dreq(dreq))

		nfs_direct_write_complete(dreq, data->inode);

}

};

/*

 * 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;

				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)