From: Vlastimil Babka <vbabka@suse.cz>
To: Omar Sandoval <osandov@osandov.com>
Cc: Dominique Martinet <asmadeus@codewreck.org>,
Thorsten Leemhuis <regressions@leemhuis.info>,
Linus Torvalds <torvalds@linux-foundation.org>,
Eric Van Hensbergen <ericvh@kernel.org>,
Christian Schoenebeck <linux_oss@crudebyte.com>,
v9fs@lists.linux.dev, linux-kernel@vger.kernel.org,
regressions@lists.linux.dev, Jason Gunthorpe <jgg@nvidia.com>,
Pedro Falcato <pedro.falcato@gmail.com>
Subject: Re: [PATCH] 9p: Avoid creating multiple slab caches with the same name
Date: Mon, 21 Oct 2024 22:18:25 +0200 [thread overview]
Message-ID: <8d09dcdc-b8bc-4d25-9afb-5eec8fb11a27@suse.cz> (raw)
In-Reply-To: <ZxafcO8KWMlXaeWE@telecaster.dhcp.thefacebook.com>
On 10/21/24 20:37, Omar Sandoval wrote:
> On Mon, Oct 21, 2024 at 10:42:02AM +0200, Vlastimil Babka wrote:
>
> FYI, drgn's CI started getting EIO errors from
> getdents("/sys/kernel/slab") that I bisected to this patch. The problem
> is that dev_name can be an arbitrary string. In my case, it is
> "/dev/root". This trips verify_dirent_name(), which fails if a filename
> contains a slash.
>
> This needs to use a different unique identifier. Maybe clnt->msize? But
> then the kmem_caches will need to be shared between different mounts
> using the same msize.
Yep, Dominique mentioned that here too:
https://lore.kernel.org/all/ZvBIl8b9RRK9jgtJ@codewreck.org/
And yes, slab has internal merging of compatible caches enabled by default.
But since it can be disabled, that would indeed result in duplicate names
again if 9p mounts didn't track and reuse caches with same msize accross
mounts on its own.
Linus's suggestion seems like the easiest fix for now.
> In any case, can this be reverted for now?
>
> Thanks,
> Omar
next prev parent reply other threads:[~2024-10-21 20:18 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-07 9:47 Pedro Falcato
2024-10-18 17:28 ` Jason Gunthorpe
2024-10-18 18:36 ` Pedro Falcato
2024-10-18 18:54 ` Thorsten Leemhuis
2024-10-18 21:38 ` Vlastimil Babka
2024-10-19 0:02 ` Dominique Martinet
2024-10-21 8:42 ` Vlastimil Babka
2024-10-21 18:37 ` Omar Sandoval
2024-10-21 18:57 ` Linus Torvalds
2024-10-21 20:06 ` Omar Sandoval
2024-10-21 23:00 ` Linus Torvalds
2024-10-21 20:18 ` Vlastimil Babka [this message]
2024-10-19 5:28 ` Linux regression tracking (Thorsten Leemhuis)
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