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Sat, 29 Aug 2026 05:13:40 -0700 (PDT) From: Wenjie Qi To: akpm@linux-foundation.org Cc: willy@infradead.org, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, baohua@kernel.org, qiwenjie@xiaomi.com Subject: Re: [PATCH] mm: filemap: tighten dropbehind completion context check Date: Sat, 29 Aug 2026 20:13:35 +0800 Message-ID: <20260829121335.3491374-1-qwjhust@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260828181035.ce6e23970d37e38b64818f10@linux-foundation.org> References: <20260820142956.1414337-1-qiwenjie@xiaomi.com> <20260828181035.ce6e23970d37e38b64818f10@linux-foundation.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit I kept the helper private to avoid an MM dependency on . After looking further at the mapped-folio case Matthew raised, I think the better fix is to retain a dropbehind folio once it is mapped. A mapping represents a competing cached user, and retaining it avoids the sleeping unmap path, so filemap no longer needs a stricter context helper; the existing in_task() guard remains. I will respin the patch on that basis.