Coda: add spin lock to protect accesses to struct coda_inode_info.
We mostly need it to protect cached user permissions. The c_flags field
is advisory, reading the wrong value is harmless and in the worst case
we hit a slow path where we have to make an extra upcall to the
userspace cache manager when revalidating a dentry or inode.
Signed-off-by: Yoshihisa Abe <yoshiabe@cs.cmu.edu>
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/coda_linux.h b/include/linux/coda_linux.h
index dcc228a..2e914d0 100644
--- a/include/linux/coda_linux.h
+++ b/include/linux/coda_linux.h
@@ -89,7 +89,11 @@
/* this will not zap the inode away */
static __inline__ void coda_flag_inode(struct inode *inode, int flag)
{
- ITOC(inode)->c_flags |= flag;
+ struct coda_inode_info *cii = ITOC(inode);
+
+ spin_lock(&cii->c_lock);
+ cii->c_flags |= flag;
+ spin_unlock(&cii->c_lock);
}
#endif