[PATCH] ide: Fix crash on repeated reset

Michal Miroslaw reported a problem (bugzilla #7023) where a user initiated
reset while the IDE layer was already resetting the channel caused a crash,
and provided a rough fix.

This is a slightly cleaner version of the fix which tracks the reset state
and blocks further reset requests while a reset is in progress.

Note this is not a security issue - random end users can't access the
ioctl in question anyway.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/ide.h

@@ -825,6 +825,9 @@ typedef struct hwgroup_s {
 	unsigned int sleeping	: 1;
 		/* BOOL: polling active & poll_timeout field valid */
 	unsigned int polling	: 1;
+	 	/* BOOL: in a polling reset situation. Must not trigger another reset yet */
+	unsigned int resetting  : 1;
+
 		/* current drive */
 	ide_drive_t *drive;
 		/* ptr to current hwif in linked-list */