[PATCH] mark ftape un-removable

From: Christoph Hellwig <hch@lst.de>

I've just grepped over the tree for reamining MOD_INC_USE_COUNT users, and
ftape is a really horrible one, it relies on MOD_{INC,DEV}_USE_COUNT in the
most horrible places + it's own bookkepping and the <= 2.4 may unload
hooks.  And although I don't have the hardware I can guarantee it doesn't
work as expected.

So let's just remove the module_exit handler and mark it unremovable, if
someone wants to fix up ftape later it's fine with me, but it's a really
scary driver..

drivers/char/ftape/compressor/zftape-compress.c

@@ -60,8 +60,6 @@
 
 /* local variables 
  */
-static int keep_module_locked = 1;
-
 static void *zftc_wrk_mem = NULL;
 static __u8 *zftc_buf     = NULL;
 static void *zftc_scratch_buf  = NULL;
@@ -268,10 +266,6 @@ static void get_next_cluster(cmpr_info *cluster, const __u8 *buff,
 
 static void zftc_lock(void)
 {
-	MOD_INC_USE_COUNT; /*  sets MOD_VISITED and MOD_USED_ONCE,
-			    *  locking is done with can_unload()
-			    */
-	keep_module_locked = 1;
 }
 
 /*  this function is needed for zftape_reset_position in zftape-io.c 
@@ -282,7 +276,6 @@ static void zftc_reset(void)
 
 	memset((void *)&cseg, '\0', sizeof(cseg));
 	zftc_stats();
-	keep_module_locked = 0;
 	TRACE_EXIT;
 }
 
@@ -555,10 +548,6 @@ static int zftc_write(int *write_cnt,
 	int buf_pos_write = pos->seg_byte_pos;
 	TRACE_FUN(ft_t_flow);
 	
-	keep_module_locked = 1;
-	MOD_INC_USE_COUNT; /*  sets MOD_VISITED and MOD_USED_ONCE,
-			    *  locking is done with can_unload()
-			    */
 	/* Note: we do not unlock the module because
 	 * there are some values cached in that `cseg' variable.  We
 	 * don't don't want to use this information when being
@@ -676,10 +665,6 @@ static int zftc_read (int *read_cnt,
 	int remaining = to_do;
 	TRACE_FUN(ft_t_flow);
 
-	keep_module_locked = 1;
-	MOD_INC_USE_COUNT; /*  sets MOD_VISITED and MOD_USED_ONCE,
-			    *  locking is done with can_unload()
-			    */
 	TRACE_CATCH(zft_allocate_cmpr_mem(volume->blk_sz),);
 	if (pos->seg_byte_pos == 0) {
 		/* new segment just read
@@ -800,10 +785,6 @@ static int zftc_seek(unsigned int new_block_pos,
 	int fast_seek_trials = 0;
 	TRACE_FUN(ft_t_flow);
 
-	keep_module_locked = 1;
-	MOD_INC_USE_COUNT; /*  sets MOD_VISITED and MOD_USED_ONCE,
-			    *  locking is done with can_unload()
-			    */
 	if (new_block_pos == 0) {
 		pos->seg_pos      = volume->start_seg;
 		pos->seg_byte_pos = 0;
@@ -1222,31 +1203,7 @@ MODULE_LICENSE("GPL");
  */
 int init_module(void)
 {
-	int result;
-
-#if 0 /* FIXME --RR */
-	if (!mod_member_present(&__this_module, can_unload))
-		return -EBUSY;
-	__this_module.can_unload = can_unload;
-#endif
-	result = zft_compressor_init();
-	keep_module_locked = 0;
-	return result;
+	return zft_compressor_init();
 }
 
-/* Called by modules package when removing the driver 
- */
-void cleanup_module(void)
-{
-	TRACE_FUN(ft_t_flow);
-
-	if (zft_cmpr_unregister() != &cmpr_ops) {
-		TRACE(ft_t_info, "failed");
-	} else {
-		TRACE(ft_t_info, "successful");
-	}
-	zftc_cleanup();
-        printk(KERN_INFO "zft-compressor successfully unloaded.\n");
-	TRACE_EXIT;
-}
 #endif /* MODULE */