Commit 1f90ee27 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Trond Myklebust
Browse files

nfs: increment i_dio_count for reads, too 



i_dio_count is used to protect dio access against truncate.  We want
to make sure there are no dio reads pending either when doing a
truncate.  I suspect on plain NFS things might work even without
this, but once we use a pnfs layout driver that access backing devices
directly things will go bad without the proper synchronization.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent 2a009ec9

fs/nfs/direct.c

+6 −3
Original line number Diff line number Diff line
@@ -235,10 +235,10 @@ static void nfs_direct_complete(struct nfs_direct_req *dreq, bool write) 
		spin_unlock(&inode->i_lock);

	}



	if (write) {

	if (write)

		nfs_zap_mapping(inode, inode->i_mapping);



	inode_dio_done(inode);

	}



	if (dreq->iocb) {

		long res = (long) dreq->error;
@@ -419,6 +419,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, 
					      loff_t pos, bool uio)

{

	struct nfs_pageio_descriptor desc;

	struct inode *inode = dreq->inode;

	ssize_t result = -EINVAL;

	size_t requested_bytes = 0;

	unsigned long seg;
@@ -427,6 +428,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, 
			     &nfs_direct_read_completion_ops);

	get_dreq(dreq);

	desc.pg_dreq = dreq;

	atomic_inc(&inode->i_dio_count);



	for (seg = 0; seg < nr_segs; seg++) {

		const struct iovec *vec = &iov[seg];
@@ -446,6 +448,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, 
	 * generic layer handle the completion.

	 */

	if (requested_bytes == 0) {

		inode_dio_done(inode);

		nfs_direct_req_release(dreq);

		return result < 0 ? result : -EIO;

	}

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