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Fri, 17 Apr 2026 14:04:40 -0700 (PDT) Date: Fri, 17 Apr 2026 21:04:38 +0000 From: Pasha Tatashin To: luca.boccassi@gmail.com Cc: kexec@lists.infradead.org, linux-mm@kvack.org, graf@amazon.com, rppt@kernel.org, pasha.tatashin@soleen.com, pratyush@kernel.org, brauner@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 1/2] liveupdate: add LUO_SESSION_MAGIC magic inode type Message-ID: References: <20260417205810.1831923-1-luca.boccassi@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260417205810.1831923-1-luca.boccassi@gmail.com> X-Rspamd-Queue-Id: DFA4280013 X-Rspamd-Server: rspam07 X-Stat-Signature: 88xiipdmr915a8346m4xpsqie56rxsfg X-Rspam-User: X-HE-Tag: 1776459881-155431 X-HE-Meta: U2FsdGVkX19ByuG13/iSetRZGKIdkMwyZLbzyFo573/Lw4oTeMJLoEwUL2uCuKY0SdGlBZwMcauQhUcR38amvLYUyqiqLmLae+Z0cLKhhC7sXKCi3k4Gk14NiV8YDUflnGyrMN3oHbG5w63viOJ7vu6+5hSqnEa9aVzOvyni2zIQoPF6G928D89HCYEmlHFD99HNrSTHqi9fisbr7n6ynuZlP2znukmAopkUtiB/OE84TkpkitiMQzQ33STEJes6K3v1hQ+Tsm95p8ymjb6A6alneyKa/E202R4dKF2uP1zIIhPrguo0xaVVGPzhDFF9argUwctOsWSAPFVXoDeCfsMLSrqstFKI8XcZ7mdF1wvTNCCOpgKYQaQanbPTA6BHkmU87y3VVd8v3OFJJwkFH5NzNxY4hi1s/prCERrPnVZkBNBbGMISmy1ERdHPhgnWz8mjzWlBi5rY0nyuAZUeAsJcZ2WZfymynL2uouizHvDnHfoYOSnD+G0FnHv3K+PhWDKR9t8fN1sb58UfElcZGaTphdvGsjp/PF2/HUh11btm89mHofgpVo5m7ZaSlrpzuUlRB6p8TkCFS7emGGq+xBSBWeUP7t8j8qVbWnbqRM1YL9mjGkI7RUzGdOQ9lQTewi68Vm4+Ph27spvJt9eTHZzVi/ZtyQ8GIcCFli3LshdKHhAyACholtBJXDE639xQZ0mZvJyDQNDOc0QeQYY+V2X+kelc4kdo8Ju3IlTNphmhtXg7t7iL9Zhepe1QCcb2llYReOPCkCSF58P29sDGYSoSMSQHHdVFkYLC0RMJk34Ldqove+XE7Nu7D4MKJUfeYSMFG00IpNrww2k+K+e7Wkwd4IiowBqgJpw5V6DFeym/+vLa8saBqsyLfVUxriGanULRKCCyJ6XsRwGkeaYBVuLI+tVeWuvQ6AfdId1b30w08pwGL5BBv1eIhJw0lOaEipbR9iD0ZBF7rnHsEbw ZYGOc0R+ 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 04-17 21:57, luca.boccassi@gmail.com wrote: > From: Luca Boccassi > > In userspace when managing LUO sessions we want to be able to identify > a FD as a LUO session, in order to be able to do the special handling > that they require in order to function as intended on kexec. > > Currently this requires scraping procfs and doing string matching on > the prefix of the dname, which is not an ideal interface. > > Add a singleton inode type with a magic value, so that we can > programmatically identify a fd as a LUO session via fstat(). > > Signed-off-by: Luca Boccassi Reviewed-by: Pasha Tatashin