20.06.2023 18:58, Jeff Layton пишет:
No, it won't. The l_pid field is populated from the file_lock->fl_pid.
That field is set when the lock is set, and never updated. So it's quite
possible for F_GETLK to return the pid of a process that no longer
exists.
In principle, we could try to address that by changing how we track lock
ownership, but that's a fairly major overhaul, and I'm not clear on any
use-cases where that matters.
OK, in this case I'll just put a comments
into the code, summarizing the info I got
from you and Matthew.
Thanks guys for all the info, its very helpful.
Now I only need to convert the current
"fundamental problem" attitude into a "not
implemented yet" via the code comment.
So my call is to be brave and just re-consider
the conclusion of that article, made 10 years
ago! :)
I think my foot has too many bullet wounds for that sort of bravery.
I am perfectly fine with leaving this thing
unimplemented. But what really bothers
me is the posix proposal, which I think was
done. Please tell me it allows fixing fl_pid
in the future (rather than to mandate -1),
and I am calm.
