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Y . Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Alexander Shishkin , Maxime Coquelin , Alexandre Torgue , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Bodo Stroesser , "Martin K . Petersen" , David Howells , Marc Dionne , Alexander Viro , Christian Brauner , Jan Kara , David Hildenbrand , "Liam R . Howlett" , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Pedro Falcato , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-mtd@lists.infradead.org, linux-staging@lists.linux.dev, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Ryan Roberts Subject: Re: [PATCH v3 05/16] fs: afs: correctly drop reference count on mapping failure Message-ID: <995afd70-d7c2-42af-8012-589b3319d31a@lucifer.local> References: <018cd0d8b2dae44de6d3952527e754e52ef02da8.1773944114.git.ljs@kernel.org> <608ba54c-f19e-4e27-8142-0870f91d6514@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <608ba54c-f19e-4e27-8142-0870f91d6514@kernel.org> X-Rspam-User: X-Stat-Signature: a3sz9z7itrj5toop9qhddmk9bhnhxu17 X-Rspamd-Queue-Id: 9AF88120018 X-Rspamd-Server: rspam03 X-HE-Tag: 1774033272-902514 X-HE-Meta: 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 FZJjGJcB CZXNLc5diEt94nmk9qkEKnzUb7+9DNGnK5kV27U3gW0ytJDimp0CUocHV3h1gdVUESvNFdm2zaQ0614f8vZ48SmyAJMRbAo35OUQhWAicDg9+LAM1+WsiHSJ4gCeFiSFBW8vdCFcZMOVlxVD/t1ZQd04tItk4uVvFR4H5QcL5xflzV/nkFc6JVaxjBP5xhw38t+SvKv7NMCL8Z84LRt49yU4T0uwEpg3D/r9IZA7r+OXeD7KfrLGXJsDXVWyUPQDeNzA9hJxGEAacZeXbAD2G0b7V3IG3vw+oYWvRAErzUTZREBVFkHOZfbm9Ng== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Mar 20, 2026 at 07:57:29PM +0100, Vlastimil Babka (SUSE) wrote: > On 3/19/26 19:23, Lorenzo Stoakes (Oracle) wrote: > > Commit 9d5403b1036c ("fs: convert most other generic_file_*mmap() users to > > .mmap_prepare()") updated AFS to use the mmap_prepare callback in favour > > of the deprecated mmap callback. > > > > However, it did not account for the fact that mmap_prepare is called > > pre-merge, and may then be merged, nor that mmap_prepare can fail to map > > due to an out of memory error. > > So that means a file can become pinned forever? OOM is probably only a > problem with fault injection in practice, but the merge case can happen. And > 9d5403b1036c is pre-6.18 LTS. Are we going to need Fixes: and Cc: stable then? That'd require backporting all of the .mapped functionality and half of this series, I don't think that's really practical. I guess I can do a manual backport of a partial revert. Thanks, Lorenzo