[PATCH] Remove compat ioctl semaphore

Originally for 2.6.16, but the semaphore causes problems for some
people so get rid of it now.

It's not needed anymore because the ioctl hash table is never changed
at run time now.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/compat.c

@@ -268,7 +268,6 @@ asmlinkage long compat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct c
 
 #define IOCTL_HASHSIZE 256
 static struct ioctl_trans *ioctl32_hash_table[IOCTL_HASHSIZE];
-static DECLARE_RWSEM(ioctl32_sem);
 
 extern struct ioctl_trans ioctl_start[];
 extern int ioctl_table_size;
@@ -390,14 +389,10 @@ asmlinkage long compat_sys_ioctl(unsigned int fd, unsigned int cmd,
 		break;
 	}
 
-	/* When register_ioctl32_conversion is finally gone remove
-	   this lock! -AK */
-	down_read(&ioctl32_sem);
 	for (t = ioctl32_hash_table[ioctl32_hash(cmd)]; t; t = t->next) {
 		if (t->cmd == cmd)
 			goto found_handler;
 	}
-	up_read(&ioctl32_sem);
 
 	if (S_ISSOCK(filp->f_dentry->d_inode->i_mode) &&
 	    cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15)) {
@@ -417,11 +412,9 @@ asmlinkage long compat_sys_ioctl(unsigned int fd, unsigned int cmd,
 		lock_kernel();
 		error = t->handler(fd, cmd, arg, filp);
 		unlock_kernel();
-		up_read(&ioctl32_sem);
 		goto out_fput;
 	}
 
-	up_read(&ioctl32_sem);
  do_ioctl:
 	error = vfs_ioctl(filp, fd, cmd, arg);
  out_fput: