From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andres Freund Date: Sun, 05 Apr 2020 22:52:40 +0000 Subject: Re: [GIT PULL] Mount and superblock notifications Message-Id: <20200405225240.kofadjkmpigfzcfy@alap3.anarazel.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit List-Id: References: <1445647.1585576702@warthog.procyon.org.uk> <1449543.1585579014@warthog.procyon.org.uk> In-Reply-To: To: Linus Torvalds Cc: David Howells , Al Viro , dray@redhat.com, Karel Zak , Miklos Szeredi , Steven Whitehouse , jlayton@redhat.com, Ian Kent , Christian Brauner , keyrings@vger.kernel.org, linux-fsdevel , Linux Kernel Mailing List Hi, On 2020-04-04 14:13:03 -0700, Linus Torvalds wrote: > And it needs to be interesting and pressing enough that those people > actually at least do a working prototype on top of a patch-set that > hasn't made it into the kernel yet. > > Now, I realize that other projects won't _upstream_ their support > before the kernel has the infrastructure, so I'm not looking for > _that_ kind of "yeah, look, project XYZ already does this and Red Hat > ships it". No, I'm looking for those outside developers who say more > than "this is a pet peeve of mine with the existing interface". I want > to see some actual use - even if it's just in a development > environment - that shows that it's (a) sufficient and (b) actually > fixes problems. FWIW, postgres remains interested in using the per-superblock events. On 2020-03-30 15:36:54 +0100, David Howells wrote: > (2) Superblock notifications. > > This one is provided to allow systemd or the desktop to more easily > detect events such as I/O errors and EDQUOT/ENOSPC. This would be of > interest to Postgres: > > https://lore.kernel.org/linux-fsdevel/20200211005626.7yqjf5rbs3vbwagd@alap3.anarazel.de/ > > But could also be used to indicate to systemd when a superblock has > had its configuration changed. What prevents me from coming up with a prototype is that the error handling pieces aren't complete, as far as I can tell: On 2020-03-30 15:36:54 +0100, David Howells wrote: > (2) Superblock events, such as R/W<->R/O changes, quota overrun and I/O > errors (not complete yet). There's afaict no notify_sb_error() callers, making it hard for me to actually test anything. The important issue for us is I/O errors, but EDQUOT/ENOSPC could also be useful (but is not urgent). Greetings, Andres Freund