On 2021/11/19 0:57, Benjamin Marzinski wrote: > On Tue, Nov 16, 2021 at 10:01:15PM +0800, lixiaokeng wrote: >> The update_map will frequently be called and there will be >> unnecessary checks of reseravtion. We add prflag to path >> to avoid this. >> >> The pp->state changes from others to up or ghost, the >> mpath_pr_event_handle should be called. The >> mpath_pr_event_handle in ev_add_path may not be called, >> so set pp->prkey PRKEY_NO when path is removed. > > This patch kind of confuses me. You only check pp->prkey before calling > mpath_pr_event_handle() in update_map(). I get from your commit message > that you are doing this to keep from frequent, unnecessary calls. But > isn't update_map() only called when a multipath device is first created, > or when multipathd stops waiting for something that it noticed during > device creation? I don't see how this can be frequently called on a > multipath device. What am I missing? > > -Ben > Discussed in the previous patch (multipathd: fix missing persistent reseravtion for active path) as follows: On Mon, 2021-09-13 at 10:32 -0500, Benjamin Marzinski wrote: > On Mon, Sep 13, 2021 at 09:01:11AM +0200, Martin Wilck wrote: >> Hello lixiaokeng, >> >> On Mon, 2021-09-13 at 10:43 +0800, lixiaokeng wrote: >>> There are two paths(sucu as sda and adb) for one LUN. The two >>> paths log in, but before the two uevents have been processed >>> (for example there are many uevent), users use multipathd add >>> path /dev/sda to cause mpatha and use mpathpersist -o -I to >>> register prkey for mpatha. The add map uevent is after add path >>> uevent, the the uevent(add sdb) will delay and missing persistent >>> reseravtion check. >>> >>> Here, we add persistent reseravtion check in update_map() which >>> is called ev_add_map(). >>> >>> Signed-off-by: Lixiaokeng <lixiaokeng@xxxxxxxxxx> >> >> Thank you, this looks ok to me. Have you tested it? >> >> I'll wait for Ben's opinion nonetheless, because he's more >> exprerienced >> with this part of the code than myself. >> >> This said, I would like to have multipathd record which paths have >> already registered the key, to avoid doing that repeatedly. >> > Other than adding this, the patch looks fine. There may be some mistakes. I mistakenly thought update_map would be called multiple times In check_path, mpath_pr_event_handle is only called pp->state changes from others to up. Some prkey changes may happen when pp->state is down, so mpath_pr_event_handle should be called even pp->prkey is PRKEY_OK. As Ben said, update_map will not be called repetitively. I think this patch should be removed. Thank Ben and Martin. Regards, Lixiaokeng -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel
