Commit ac1171bd authored by Jinlong Chen's avatar Jinlong Chen Committed by Jens Axboe
Browse files

elevator: update the document of elevator_switch 



We no longer support falling back to the old io scheduler if switching to
the new one fails. Update the document to indicate that.

Fixes: a1ce35fa ("block: remove dead elevator code")
Signed-off-by: default avatarJinlong Chen <nickyc975@zju.edu.cn>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/94250961689ba7d2e67a7d9e7995a11166fedb31.1669126766.git.nickyc975@zju.edu.cn


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 93c68cc4

block/elevator.c

+4 −4
Original line number Diff line number Diff line
@@ -650,10 +650,10 @@ void elevator_init_mq(struct request_queue *q) 
}



/*

 * switch to new_e io scheduler. be careful not to introduce deadlocks -

 * we don't free the old io scheduler, before we have allocated what we

 * need for the new one. this way we have a chance of going back to the old

 * one, if the new one fails init for some reason.

 * Switch to new_e io scheduler.

 *

 * If switching fails, we are most likely running out of memory and not able

 * to restore the old io scheduler, so leaving the io scheduler being none.

 */

int elevator_switch(struct request_queue *q, struct elevator_type *new_e)

{