From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yann E. MORIN Date: Tue, 3 Apr 2018 22:48:20 +0200 Subject: [Buildroot] Per-package download folders and Git caching In-Reply-To: <22d8a943-fdb2-f6ab-d81e-d9e0cc9b4df5@mind.be> References: <20180403141703.21cd24fe@windsurf> <041a5a2a-3f9d-c76e-4c6d-d22ef11cad43@mind.be> <876058qvi4.fsf@dell.be.48ers.dk> <20180403162324.GB2335@scaer> <87k1top74p.fsf@dell.be.48ers.dk> <20180403174904.GE2335@scaer> <22d8a943-fdb2-f6ab-d81e-d9e0cc9b4df5@mind.be> Message-ID: <20180403204820.GF2335@scaer> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Arnout, All, On 2018-04-03 22:44 +0200, Arnout Vandecappelle spake thusly: > On 03-04-18 19:49, Yann E. MORIN wrote: > > Peter, All, > > > > On 2018-04-03 18:49 +0200, Peter Korsgaard spake thusly: > >>>>>>> "Yann" == Yann E MORIN writes: > >> > Should we do a cp if ln fails, then? > >> That sounds like a sensible fallback, yes. > > > > I was about to do so, but then we're back to a situation where we have > > to guarantee the atomicity. > > > > This is currently possible, because the dl-wrapper now runs under flock. > > But we are going to optimise the locking with a more fine-grained > > solution soonish. > > > > To be noted: the current code is not atomic-safe either, because we do > > have a TOCTTOU situation... > > > > So, we'll have to again play tricks with atomicity... > > > > We can't use flock again, because the destination directory is already > > locked, and there is not destination file to lock to start with... > > > > So, maybe the full solution will in fact to really implement the more > > fine-grained solution... I'll see to it. > > Note that for the specific case I mentioned (hardlinks may not work over samba > or VM shares), flock will fail as well... Wait... So you're saying that we borked a working situation for a certain class of users, now? Damn... :-/ And why would flock fail on those (curious)? > Maybe we should just wait until someone complains so they can test whatever > solution we come up with. In the end, yes, probably... Regards, Yann E. MORIN. -- .-----------------.--------------------.------------------.--------------------. | Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: | | +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ | | +33 223 225 172 `------------.-------: X AGAINST | \e/ There is no | | http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. | '------------------------------^-------^------------------^--------------------'