When a resync or online verify is finished or aborted,
drbd does a bulk write-out of changed bitmap pages.
If *in that very moment* a new verify or resync is triggered,
this can race:
ASSERT( !test_bit(BITMAP_IO, &mdev->flags) ) in drbd_main.c
FIXME going to queue 'set_n_write from StartingSync' but 'write from resync_finished' still pending?
and similar.
This can be observed with e.g. tight invalidate loops in test scripts,
and probably has no real-life implication.
Still, that race can be solved by first quiescen the device,
before starting a new resync or verify.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
/* If there is still bitmap IO pending, probably because of a previous
* resync just being finished, wait for it before requesting a new resync. */
/* If there is still bitmap IO pending, probably because of a previous
* resync just being finished, wait for it before requesting a new resync. */
wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
retcode = _drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_T), CS_ORDERED);
wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
retcode = _drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_T), CS_ORDERED);
retcode = drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_T));
}
retcode = drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_T));
}
reply->ret_code = retcode;
return 0;
reply->ret_code = retcode;
return 0;
/* If there is still bitmap IO pending, probably because of a previous
* resync just being finished, wait for it before requesting a new resync. */
/* If there is still bitmap IO pending, probably because of a previous
* resync just being finished, wait for it before requesting a new resync. */
wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
retcode = _drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_S), CS_ORDERED);
wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
retcode = _drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_S), CS_ORDERED);
} else
retcode = drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_S));
}
} else
retcode = drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_S));
}
reply->ret_code = retcode;
return 0;
reply->ret_code = retcode;
return 0;
/* If there is still bitmap IO pending, e.g. previous resync or verify
* just being finished, wait for it before requesting a new resync. */
/* If there is still bitmap IO pending, e.g. previous resync or verify
* just being finished, wait for it before requesting a new resync. */
wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
/* w_make_ov_request expects position to be aligned */
mdev->ov_start_sector = args.start_sector & ~BM_SECT_PER_BIT;
reply->ret_code = drbd_request_state(mdev,NS(conn,C_VERIFY_S));
wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
/* w_make_ov_request expects position to be aligned */
mdev->ov_start_sector = args.start_sector & ~BM_SECT_PER_BIT;
reply->ret_code = drbd_request_state(mdev,NS(conn,C_VERIFY_S));