selinux: Convert isec->lock into a spinlock
Convert isec->lock from a mutex into a spinlock. Instead of holding
the lock while sleeping in inode_doinit_with_dentry, set
isec->initialized to LABEL_PENDING and release the lock. Then, when
the sid has been determined, re-acquire the lock. If isec->initialized
is still set to LABEL_PENDING, set isec->sid; otherwise, the sid has
been set by another task (LABEL_INITIALIZED) or invalidated
(LABEL_INVALID) in the meantime.
This fixes a deadlock on gfs2 where
* one task is in inode_doinit_with_dentry -> gfs2_getxattr, holds
isec->lock, and tries to acquire the inode's glock, and
* another task is in do_xmote -> inode_go_inval ->
selinux_inode_invalidate_secctx, holds the inode's glock, and
tries to acquire isec->lock.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
[PM: minor tweaks to keep checkpatch.pl happy]
Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index c21e135..e8dab0f 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -39,7 +39,8 @@
enum label_initialized {
LABEL_INVALID, /* invalid or not initialized */
- LABEL_INITIALIZED /* initialized */
+ LABEL_INITIALIZED, /* initialized */
+ LABEL_PENDING
};
struct inode_security_struct {
@@ -52,7 +53,7 @@
u32 sid; /* SID of this object */
u16 sclass; /* security class of this object */
unsigned char initialized; /* initialization flag */
- struct mutex lock;
+ spinlock_t lock;
};
struct file_security_struct {