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Received: from viro by zeniv.linux.org.uk with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vEAb5-0000000DNn5-15k7; Wed, 29 Oct 2025 18:08:35 +0000 Date: Wed, 29 Oct 2025 18:08:35 +0000 From: Al Viro To: Ard Biesheuvel Cc: James Bottomley , linux-fsdevel@vger.kernel.org, torvalds@linux-foundation.org, brauner@kernel.org, jack@suse.cz, raven@themaw.net, miklos@szeredi.hu, neil@brown.name, a.hindborg@kernel.org, linux-mm@kvack.org, linux-efi@vger.kernel.org, ocfs2-devel@lists.linux.dev, kees@kernel.org, rostedt@goodmis.org, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, paul@paul-moore.com, casey@schaufler-ca.com, linuxppc-dev@lists.ozlabs.org, john.johansen@canonical.com, selinux@vger.kernel.org, borntraeger@linux.ibm.com, bpf@vger.kernel.org Subject: Re: [PATCH v2 22/50] convert efivarfs Message-ID: <20251029180835.GT2441659@ZenIV> References: <20251028004614.393374-1-viro@zeniv.linux.org.uk> <20251028004614.393374-23-viro@zeniv.linux.org.uk> <66300d81c5e127e3bca8c6c4d997da386b142004.camel@HansenPartnership.com> <20251028174540.GN2441659@ZenIV> <20251028210805.GP2441659@ZenIV> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 15D7840002 X-Rspamd-Server: rspam11 X-Rspam-User: X-Stat-Signature: o6exy78pwbp7iht1i58nsx1acpq95b8b X-HE-Tag: 1761761320-763218 X-HE-Meta: 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 yDsPo9od WLJWJLKaEakL3ljRwhXiMKs3nbGVEi2f5pGCsTmak7rPJWzWFeQ6ZoapoSLfI2IK7vKGQA/GUGo5E2IZoey3ACBoOzQiS+gRMteGauC1UfGnZKDG59oiZFVfbUW9uRdnEhAcS7A8aC7IFp9Y+QNXZc8Z6tywwmGRVYJk/ODiq1xV0y1L1BFLMh4fkjB6r06gPkcPMlBOz74uQxD6o9bjQI0YjW1ichJ7B/wAdEfA6JJMiNmMtLVK7WXqd5ZBD0peiR2Cpha+1hEopy1d6ss3tc0zdrWCIxkIjjADAW5YNcVRqU7WhPRz2rfqS2ct776NU+MZ6wTcLDJ395VdHFWJaSUnKqyDPxXgi9fOy++0UGIkraBP43n5hE/Sz39GeEzovT3/svHkTSh8EdC4MKCgp6jyfiLOOrczzt68KzVvMRVtz2sS2n0Xelyul2WIIuJ/uzEQM X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Oct 28, 2025 at 10:34:51PM +0100, Ard Biesheuvel wrote: > I'll let James respond to the specifics of your suggestion, but I'll > just note that this code has a rather convoluted history, as we used > to have two separate pseudo-filesystem drivers, up until a few years > ago: the sysfs based 'efivars' and this efivarfs driver. Given that > modifications in one needed to be visible in the other, they shared a > linked list that shadowed the state of the underlying variable store. > 'efivars' was removed years ago, but it was only recently that James > replaced the linked list in this driver with the dentry cache as the > shadow mechanism. Hmm... Another question about that code: is efivar_get_variable() safe outside of efivar_lock()?