From: Erez Zadok <ezk@cs.sunysb.edu>
Date: Sat, 30 Apr 2011 05:34:00 +0000 (-0400)
Subject: Unionfs: reorder initializations in ->permission
X-Git-Url: https://git.fsl.cs.sunysb.edu/?a=commitdiff_plain;h=1a9255800914f2f175c6a7a555bbd8657834c0c2;p=unionfs-2.6.39.y.git

Unionfs: reorder initializations in ->permission

First igrab, then reference the inode in question; and do all this after
checking for IPERM_FLAG_RCU.

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

diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index 3d34394306c..21acb882fae 100644
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -789,19 +789,23 @@ static int unionfs_permission(struct inode *inode, int mask, unsigned int flags)
 	struct inode *lower_inode = NULL;
 	int err = 0;
 	int bindex, bstart, bend;
-	const int is_file = !S_ISDIR(inode->i_mode);
+	int is_file;
 	const int write_mask = (mask & MAY_WRITE) && !(mask & MAY_READ);
-	struct inode *inode_grabbed = igrab(inode);
-	struct dentry *dentry = d_find_alias(inode);
+	struct inode *inode_grabbed;
+	struct dentry *dentry;
 
 	if (flags & IPERM_FLAG_RCU) {
 		err = -ECHILD;
 		goto out_nograb;
 	}
 
+	dentry = d_find_alias(inode);
 	if (dentry)
 		unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
 
+	inode_grabbed = igrab(inode);
+	is_file = !S_ISDIR(inode->i_mode);
+
 	if (!UNIONFS_I(inode)->lower_inodes) {
 		if (is_file)	/* dirs can be unlinked but chdir'ed to */
 			err = -ESTALE;	/* force revalidate */