at 22:50 on Fri 13-Jan-2017 Al Viro (v...@zeniv.linux.org.uk) wrote: > Or, even better, we can get rid of all wraparound-related crap if we > calculate the final value of pipe->nrbufs and watch for _that_ as > loop condition: > > diff --git a/lib/iov_iter.c b/lib/iov_iter.c > index 25f572303801..e68604ae3ced 100644 > --- a/lib/iov_iter.c > +++ b/lib/iov_iter.c > @@ -730,43 +730,50 @@ size_t iov_iter_copy_from_user_atomic(struct page *page, > } > EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); > > +static inline void pipe_truncate(struct iov_iter *i) ...
I've dragged an old box out of the storeroom and upgraded and configured it so it reproduced the problem. With the patch, the mail is sent with no hang # uname -a Linux maglor 4.9.3-dirty #3 SMP Sat Jan 14 12:13:45 GMT 2017 x86_64 AMD Athlon(tm) II X2 270 Processor AuthenticAMD GNU/Linux Jan 14 12:56:01 maglor cron[741]: (root) CMD (date; /work/chroot-shared/test.sh; date) Jan 14 12:56:01 maglor postfix/pickup[649]: 8577A604F2: uid=0 from=<root> Jan 14 12:56:01 maglor postfix/cleanup[752]: 8577A604F2: message-id=<20170114125601.8577A604F2@maglor.localdomain> Jan 14 12:56:01 maglor postfix/qmgr[650]: 8577A604F2: from=<root@maglor.localdomain>, size=735, nrcpt=1 (queue active) Jan 14 12:56:01 maglor postfix/smtp[754]: 8577A604F2: to=<alan@frodo.localnet>, orig_to=<root>, relay=frodo.localnet[192.168.21.2]:25, delay=0.54, delays=0.43/0/0.04/0.07, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as A08CC440065) Jan 14 12:56:01 maglor postfix/qmgr[650]: 8577A604F2: removed No other problems are apparent. I'll run this for a bit, then apply it to my workstation (which I'm rather fond of) and make sure there are no new regressions. -- Alan J. Wylie http://www.wylie.me.uk/ Dance like no-one's watching. / Encrypt like everyone is. Security is inversely proportional to convenience
