NFS: Do not serialise O_DIRECT reads and writes
Allow dio requests to be scheduled in parallel, but ensuring that they
do not conflict with buffered I/O.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 0169eca..6d0e880 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -578,17 +578,12 @@
if (!count)
goto out;
- inode_lock(inode);
- result = nfs_sync_mapping(mapping);
- if (result)
- goto out_unlock;
-
task_io_account_read(count);
result = -ENOMEM;
dreq = nfs_direct_req_alloc();
if (dreq == NULL)
- goto out_unlock;
+ goto out;
dreq->inode = inode;
dreq->bytes_left = dreq->max_count = count;
@@ -603,10 +598,12 @@
if (!is_sync_kiocb(iocb))
dreq->iocb = iocb;
+ nfs_start_io_direct(inode);
+
NFS_I(inode)->read_io += count;
result = nfs_direct_read_schedule_iovec(dreq, iter, iocb->ki_pos);
- inode_unlock(inode);
+ nfs_end_io_direct(inode);
if (!result) {
result = nfs_direct_wait(dreq);
@@ -614,13 +611,8 @@
iocb->ki_pos += result;
}
- nfs_direct_req_release(dreq);
- return result;
-
out_release:
nfs_direct_req_release(dreq);
-out_unlock:
- inode_unlock(inode);
out:
return result;
}
@@ -1008,25 +1000,12 @@
pos = iocb->ki_pos;
end = (pos + iov_iter_count(iter) - 1) >> PAGE_SHIFT;
- inode_lock(inode);
-
- result = nfs_sync_mapping(mapping);
- if (result)
- goto out_unlock;
-
- if (mapping->nrpages) {
- result = invalidate_inode_pages2_range(mapping,
- pos >> PAGE_SHIFT, end);
- if (result)
- goto out_unlock;
- }
-
task_io_account_write(count);
result = -ENOMEM;
dreq = nfs_direct_req_alloc();
if (!dreq)
- goto out_unlock;
+ goto out;
dreq->inode = inode;
dreq->bytes_left = dreq->max_count = count;
@@ -1041,6 +1020,8 @@
if (!is_sync_kiocb(iocb))
dreq->iocb = iocb;
+ nfs_start_io_direct(inode);
+
result = nfs_direct_write_schedule_iovec(dreq, iter, pos);
if (mapping->nrpages) {
@@ -1048,7 +1029,7 @@
pos >> PAGE_SHIFT, end);
}
- inode_unlock(inode);
+ nfs_end_io_direct(inode);
if (!result) {
result = nfs_direct_wait(dreq);
@@ -1058,13 +1039,9 @@
generic_write_sync(iocb, result);
}
}
- nfs_direct_req_release(dreq);
- return result;
-
out_release:
nfs_direct_req_release(dreq);
-out_unlock:
- inode_unlock(inode);
+out:
return result;
}