[PATCH 2/4] ovl: get rid of iterate wrapper

[Miklos Szeredi <mszeredi@xxxxxxxxxx>]

Commit 3e3271549670 ("vfs: get rid of old '->iterate' directory operation")
added a wrapper around ovl_iterate() to lock the inode exclusive.

Use the overlayfs private inode lock instead to provide exclusive locking.

Add ovl_inode_lock()/_unlock() to ovl_iterate() and replace
inode_lock/_unlock() with the ovl_ variant in ovl_dir_llseek() and
ovl_dir_release().

This replacement is valid, because the inode lock was taken only to provide
exclusion between these functions (for other files referring to the same
inode).

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
 fs/overlayfs/readdir.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index b894a97f8ef8..edee9f86f469 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -758,6 +758,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
 	if (!ctx->pos)
 		ovl_dir_reset(file);
 
+	ovl_inode_lock(file_inode(file));
 	if (od->is_real) {
 		/*
 		 * If parent is merge, then need to adjust d_ino for '..', if
@@ -806,6 +807,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
 	}
 	err = 0;
 out:
+	ovl_inode_unlock(file_inode(file));
 	revert_creds(old_cred);
 	return err;
 }
@@ -815,7 +817,7 @@ static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin)
 	loff_t res;
 	struct ovl_dir_file *od = file->private_data;
 
-	inode_lock(file_inode(file));
+	ovl_inode_lock(file_inode(file));
 	if (!file->f_pos)
 		ovl_dir_reset(file);
 
@@ -845,7 +847,7 @@ static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin)
 		res = offset;
 	}
 out_unlock:
-	inode_unlock(file_inode(file));
+	ovl_inode_unlock(file_inode(file));
 
 	return res;
 }
@@ -929,9 +931,9 @@ static int ovl_dir_release(struct inode *inode, struct file *file)
 	struct ovl_dir_file *od = file->private_data;
 
 	if (od->cache) {
-		inode_lock(inode);
+		ovl_inode_lock(inode);
 		ovl_cache_put(od, inode);
-		inode_unlock(inode);
+		ovl_inode_unlock(inode);
 	}
 	fput(od->realfile);
 	if (od->upperfile)
@@ -966,11 +968,10 @@ static int ovl_dir_open(struct inode *inode, struct file *file)
 	return 0;
 }
 
-WRAP_DIR_ITER(ovl_iterate) // FIXME!
 const struct file_operations ovl_dir_operations = {
 	.read		= generic_read_dir,
 	.open		= ovl_dir_open,
-	.iterate_shared	= shared_ovl_iterate,
+	.iterate_shared	= ovl_iterate,
 	.llseek		= ovl_dir_llseek,
 	.fsync		= ovl_dir_fsync,
 	.release	= ovl_dir_release,
-- 
2.44.0