Commit 8f94004e authored by Jens Axboe's avatar Jens Axboe
Browse files

cdrom: don't attempt to fiddle with cdo->capability 



We can't modify cdo->capability as it is defined as a const.
Change the modification hack to just WARN_ON_ONCE() if we hit
any of the invalid combinations.

This fixes a regression for pcd, which doesn't work after the
constify patch.

Fixes: 853fe1bf ("cdrom: Make device operations read-only")
Tested-by: default avatarOndrej Zary <linux@rainbow-software.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 5e27891e

drivers/cdrom/cdrom.c

+13 −14
Original line number Diff line number Diff line
@@ -410,10 +410,10 @@ static int cdrom_get_disc_info(struct cdrom_device_info *cdi, 
 * hack to have the capability flags defined const, while we can still

 * change it here without gcc complaining at every line.

 */

#define ENSURE(call, bits)			\

#define ENSURE(cdo, call, bits)					\

do {								\

	if (cdo->call == NULL)					\

		*change_capability &= ~(bits);	\

		WARN_ON_ONCE((cdo)->capability & (bits));	\

} while (0)



/*
@@ -589,7 +589,6 @@ int register_cdrom(struct cdrom_device_info *cdi) 
{

	static char banner_printed;

	const struct cdrom_device_ops *cdo = cdi->ops;

	int *change_capability = (int *)&cdo->capability; /* hack */



	cd_dbg(CD_OPEN, "entering register_cdrom\n");
@@ -601,16 +600,16 @@ int register_cdrom(struct cdrom_device_info *cdi) 
		cdrom_sysctl_register();

	}



	ENSURE(drive_status, CDC_DRIVE_STATUS);

	ENSURE(cdo, drive_status, CDC_DRIVE_STATUS);

	if (cdo->check_events == NULL && cdo->media_changed == NULL)

		*change_capability = ~(CDC_MEDIA_CHANGED | CDC_SELECT_DISC);

	ENSURE(tray_move, CDC_CLOSE_TRAY | CDC_OPEN_TRAY);

	ENSURE(lock_door, CDC_LOCK);

	ENSURE(select_speed, CDC_SELECT_SPEED);

	ENSURE(get_last_session, CDC_MULTI_SESSION);

	ENSURE(get_mcn, CDC_MCN);

	ENSURE(reset, CDC_RESET);

	ENSURE(generic_packet, CDC_GENERIC_PACKET);

		WARN_ON_ONCE(cdo->capability & (CDC_MEDIA_CHANGED | CDC_SELECT_DISC));

	ENSURE(cdo, tray_move, CDC_CLOSE_TRAY | CDC_OPEN_TRAY);

	ENSURE(cdo, lock_door, CDC_LOCK);

	ENSURE(cdo, select_speed, CDC_SELECT_SPEED);

	ENSURE(cdo, get_last_session, CDC_MULTI_SESSION);

	ENSURE(cdo, get_mcn, CDC_MCN);

	ENSURE(cdo, reset, CDC_RESET);

	ENSURE(cdo, generic_packet, CDC_GENERIC_PACKET);

	cdi->mc_flags = 0;

	cdi->options = CDO_USE_FFLAGS;

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