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s390/dasd: fix possibly missed path verification

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__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: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Link: https://lore.kernel.org/r/20211020115124.1735254-8-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Stefan Haberland 2021-10-20 13:51:24 +02:00 committed by Jens Axboe
parent 9dffede011
commit a8e5d491df
2 changed files with 15 additions and 3 deletions
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9
drivers/s390/block/dasd.c
View File

@ -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);
}
};

9
drivers/s390/block/dasd_int.h
View File

@ -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