Smack: fuse mount hang fix
The d_instantiate hook for Smack can hang on the root inode of a
filesystem if the file system code has not really done all the set-up.
Fuse is known to encounter this problem.
This change detects an attempt to instantiate a root inode and addresses
it early in the processing, before any attempt is made to do something
that might hang.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Tested-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index b5c8f92..4a09293 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1881,6 +1881,18 @@
final = sbsp->smk_default;
/*
+ * If this is the root inode the superblock
+ * may be in the process of initialization.
+ * If that is the case use the root value out
+ * of the superblock.
+ */
+ if (opt_dentry->d_parent == opt_dentry) {
+ isp->smk_inode = sbsp->smk_root;
+ isp->smk_flags |= SMK_INODE_INSTANT;
+ goto unlockandout;
+ }
+
+ /*
* This is pretty hackish.
* Casey says that we shouldn't have to do
* file system specific code, but it does help