Commit a8e5d491 authored by Stefan Haberland's avatar Stefan Haberland Committed by Jens Axboe
Browse files

s390/dasd: fix possibly missed path verification 



__dasd_device_check_path_events() calls the discipline path event handler.
This handler can leave the 'to be verified pathmask' populated for an
additional verification.

There is a race window where the worker has finished before
dasd_path_clear_all_verify() is called which resets the tbvpm.

Due to this there could be outstanding path verifications missed.

Fix by clearing the pathmasks before calling the handler and add them
again in case of an error.

Signed-off-by: default avatarStefan Haberland <sth@linux.ibm.com>
Reviewed-by: default avatarJan Hoeppner <hoeppner@linux.ibm.com>
Link: https://lore.kernel.org/r/20211020115124.1735254-8-sth@linux.ibm.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 9dffede0

drivers/s390/block/dasd.c

+6 −3
Original line number Diff line number Diff line
@@ -2077,12 +2077,15 @@ static void __dasd_device_check_path_events(struct dasd_device *device) 


	if (device->stopped & ~(DASD_STOPPED_DC_WAIT))

		return;



	dasd_path_clear_all_verify(device);

	dasd_path_clear_all_fcsec(device);



	rc = device->discipline->pe_handler(device, tbvpm, fcsecpm);

	if (rc) {

		dasd_path_add_tbvpm(device, tbvpm);

		dasd_path_add_fcsecpm(device, fcsecpm);

		dasd_device_set_timer(device, 50);

	} else {

		dasd_path_clear_all_verify(device);

		dasd_path_clear_all_fcsec(device);

	}

};

drivers/s390/block/dasd_int.h

+9 −0
Original line number Diff line number Diff line
@@ -1305,6 +1305,15 @@ static inline void dasd_path_add_ppm(struct dasd_device *device, __u8 pm) 
			dasd_path_preferred(device, chp);

}



static inline void dasd_path_add_fcsecpm(struct dasd_device *device, __u8 pm)

{

	int chp;



	for (chp = 0; chp < 8; chp++)

		if (pm & (0x80 >> chp))

			dasd_path_fcsec(device, chp);

}



/*

 * set functions for path masks

 * the existing path mask will be replaced by the given path mask