From: Erez Zadok <ezk@cs.sunysb.edu>
Date: Tue, 6 Sep 2011 01:20:36 +0000 (-0400)
Subject: Unionfs: remove whiteout of opened but unlinked file from readonly branch
X-Git-Url: https://git.fsl.cs.sunysb.edu/?a=commitdiff_plain;h=f0b47c39f7d479dd7927e321d7ed84fc467116c9;p=unionfs-2.6.27.y.git

Unionfs: remove whiteout of opened but unlinked file from readonly branch

If we unlink an opened file in a readonly branch, then we create a whiteout.
But then if if ftruncate it, we copyup a zero-length file.  So we have to
delete the whiteout.

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
---

diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index ee655412dc5..d04f3a225d4 100644
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -962,6 +962,16 @@ static int unionfs_setattr(struct dentry *dentry, struct iattr *ia)
 		/* get updated lower_dentry/inode after copyup */
 		lower_dentry = unionfs_lower_dentry(dentry);
 		lower_inode = unionfs_lower_inode(inode);
+		/*
+		 * check for whiteouts in writeable branch, and remove them
+		 * if necessary.
+		 */
+		if (lower_dentry) {
+			err = check_unlink_whiteout(dentry, lower_dentry,
+						    bindex);
+			if (err > 0) /* ignore if whiteout found and removed */
+				err = 0;
+		}
 	}
 
 	/*