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

Commit d0b9875d authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Trond Myklebust
Browse files

nfs: take i_mutex during direct I/O reads 



We'll need the i_mutex to prevent i_dio_count from incrementing while
truncate is waiting for it to reach zero, and protects against having
the pagecache repopulated after we flushed it.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent 22cd1bf1

fs/nfs/direct.c

+12 −2
Original line number Diff line number Diff line
@@ -500,16 +500,17 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, 
	if (!count)

		goto out;



	mutex_lock(&inode->i_mutex);

	result = nfs_sync_mapping(mapping);

	if (result)

		goto out;

		goto out_unlock;



	task_io_account_read(count);



	result = -ENOMEM;

	dreq = nfs_direct_req_alloc();

	if (dreq == NULL)

		goto out;

		goto out_unlock;



	dreq->inode = inode;

	dreq->bytes_left = iov_length(iov, nr_segs);
@@ -525,13 +526,22 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, 


	NFS_I(inode)->read_io += iov_length(iov, nr_segs);

	result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos, uio);



	mutex_unlock(&inode->i_mutex);



	if (!result) {

		result = nfs_direct_wait(dreq);

		if (result > 0)

			iocb->ki_pos = pos + result;

	}



	nfs_direct_req_release(dreq);

	return result;



out_release:

	nfs_direct_req_release(dreq);

out_unlock:

	mutex_unlock(&inode->i_mutex);

out:

	return result;

}