From d0b9875d65c1abcc9d405d648660dfb919353959 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 14 Nov 2013 08:50:33 -0800 Subject: 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: Christoph Hellwig Signed-off-by: Trond Myklebust --- fs/nfs/direct.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index cbfbd17eae85..85e4e4be401a 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -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; } -- cgit v1.2.3