Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 487b8372 authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust
Browse files

NFS: support EIOCBQUEUED return in direct read path 



For async iocb's, the NFS direct read path should return EIOCBQUEUED and
call aio_complete when all the requested reads are finished.  The
synchronous part of the NFS direct read path behaves exactly as it was
before.

Test plan:
aio-stress with "-O".  OraSim.

Signed-off-by: default avatarChuck Lever <cel@netapp.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 99514f8f

fs/nfs/direct.c

+21 −4
Original line number Diff line number Diff line
@@ -177,6 +177,7 @@ static struct nfs_direct_req *nfs_direct_read_alloc(size_t nbytes, size_t rsize) 
	kref_init(&dreq->kref);

	init_waitqueue_head(&dreq->wait);

	INIT_LIST_HEAD(&dreq->list);

	dreq->iocb = NULL;

	atomic_set(&dreq->count, 0);

	atomic_set(&dreq->error, 0);
@@ -213,6 +214,10 @@ static struct nfs_direct_req *nfs_direct_read_alloc(size_t nbytes, size_t rsize) 
 * 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_read_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.

 */

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

{
@@ -228,6 +233,12 @@ static void nfs_direct_read_result(struct rpc_task *task, void *calldata) 


	if (unlikely(atomic_dec_and_test(&dreq->complete))) {

		nfs_free_user_pages(dreq->pages, dreq->npages, 1);

		if (dreq->iocb) {

			long res = atomic_read(&dreq->error);

			if (!res)

				res = atomic_read(&dreq->count);

			aio_complete(dreq->iocb, res, 0);

		} else

			wake_up(&dreq->wait);

		kref_put(&dreq->kref, nfs_direct_req_release);

	}
@@ -309,8 +320,13 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long 
 */

static ssize_t nfs_direct_read_wait(struct nfs_direct_req *dreq, int intr)

{

	int result = 0;

	int result = -EIOCBQUEUED;



	/* Async requests don't wait here */

 	if (dreq->iocb)

		goto out;



	result = 0;

	if (intr) {

		result = wait_event_interruptible(dreq->wait,

					(atomic_read(&dreq->complete) == 0));
@@ -323,6 +339,7 @@ static ssize_t nfs_direct_read_wait(struct nfs_direct_req *dreq, int intr) 
	if (!result)

		result = atomic_read(&dreq->count);



out:

	kref_put(&dreq->kref, nfs_direct_req_release);

	return (ssize_t) result;

}
@@ -343,6 +360,8 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size 
	dreq->npages = nr_pages;

	dreq->inode = inode;

	dreq->filp = iocb->ki_filp;

	if (!is_sync_kiocb(iocb))

		dreq->iocb = iocb;



	nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count);

	rpc_clnt_sigmask(clnt, &oldset);
@@ -534,8 +553,6 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count, 
		file->f_dentry->d_name.name,

		(unsigned long) count, (long long) pos);



	if (!is_sync_kiocb(iocb))

		goto out;

	if (count < 0)

		goto out;

	retval = -EFAULT;