summaryrefslogtreecommitdiffstats
path: root/fs/overlayfs/inode.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/overlayfs/inode.c')
-rw-r--r--fs/overlayfs/inode.c48
1 files changed, 48 insertions, 0 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index b48273e846ad..f7eba21effa5 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -777,6 +777,54 @@ struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
return inode;
}
+bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir)
+{
+ struct inode *key = d_inode(dir);
+ struct inode *trap;
+ bool res;
+
+ trap = ilookup5(sb, (unsigned long) key, ovl_inode_test, key);
+ if (!trap)
+ return false;
+
+ res = IS_DEADDIR(trap) && !ovl_inode_upper(trap) &&
+ !ovl_inode_lower(trap);
+
+ iput(trap);
+ return res;
+}
+
+/*
+ * Create an inode cache entry for layer root dir, that will intentionally
+ * fail ovl_verify_inode(), so any lookup that will find some layer root
+ * will fail.
+ */
+struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir)
+{
+ struct inode *key = d_inode(dir);
+ struct inode *trap;
+
+ if (!d_is_dir(dir))
+ return ERR_PTR(-ENOTDIR);
+
+ trap = iget5_locked(sb, (unsigned long) key, ovl_inode_test,
+ ovl_inode_set, key);
+ if (!trap)
+ return ERR_PTR(-ENOMEM);
+
+ if (!(trap->i_state & I_NEW)) {
+ /* Conflicting layer roots? */
+ iput(trap);
+ return ERR_PTR(-ELOOP);
+ }
+
+ trap->i_mode = S_IFDIR;
+ trap->i_flags = S_DEAD;
+ unlock_new_inode(trap);
+
+ return trap;
+}
+
/*
* Does overlay inode need to be hashed by lower inode?
*/