[PATCH 4/8] iomap: Move lockdep_assert_held() to iomap_dio_rw() calls

[Goldwyn Rodrigues <rgoldwyn@xxxxxxx>]

From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>

Filesystems such as btrfs can perform direct I/O without holding the
inode->i_rwsem in some of the cases like writing within i_size.
So, remove the check for lockdep_assert_held() in iomap_dio_rw()
and move it to where iomap_dio_rw() is called so the checks are
in place.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
---
 fs/gfs2/file.c       | 4 ++++
 fs/iomap/direct-io.c | 2 --
 fs/xfs/xfs_file.c    | 9 ++++++++-
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 9d58295ccf7a..d0517a78640b 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -771,6 +771,8 @@ static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
 	if (ret)
 		goto out_uninit;
 
+	lockdep_assert_held(&file_inode(file)->i_rwsem);
+
 	ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL,
 			   is_sync_kiocb(iocb));
 
@@ -807,6 +809,8 @@ static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
 	if (offset + len > i_size_read(&ip->i_inode))
 		goto out;
 
+	lockdep_assert_held(&inode->i_rwsem);
+
 	ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL,
 			   is_sync_kiocb(iocb));
 
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 1a3bf3bd86fb..41c1e7c20a1f 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -415,8 +415,6 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 	struct blk_plug plug;
 	struct iomap_dio *dio;
 
-	lockdep_assert_held(&inode->i_rwsem);
-
 	if (!count)
 		return 0;
 
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index c93250108952..dfaccd4d6e6c 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -176,7 +176,8 @@ xfs_file_dio_aio_read(
 	struct kiocb		*iocb,
 	struct iov_iter		*to)
 {
-	struct xfs_inode	*ip = XFS_I(file_inode(iocb->ki_filp));
+	struct inode		*inode = file_inode(iocb->ki_filp);
+	struct xfs_inode	*ip = XFS_I(inode);
 	size_t			count = iov_iter_count(to);
 	ssize_t			ret;
 
@@ -188,6 +189,9 @@ xfs_file_dio_aio_read(
 	file_accessed(iocb->ki_filp);
 
 	xfs_ilock(ip, XFS_IOLOCK_SHARED);
+
+	lockdep_assert_held(&inode->i_rwsem);
+
 	ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL,
 			is_sync_kiocb(iocb));
 	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
@@ -547,6 +551,9 @@ xfs_file_dio_aio_write(
 	}
 
 	trace_xfs_file_direct_write(ip, count, iocb->ki_pos);
+
+	lockdep_assert_held(&inode->i_rwsem);
+
 	/*
 	 * If unaligned, this is the only IO in-flight. Wait on it before we
 	 * release the iolock to prevent subsequent overlapping IO.
-- 
2.16.4