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charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 (3.60.2-1.fc44) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Fri, 2026-08-21 at 15:04 -0700, John Hubbard wrote: >=20 > You have delved too deep, and now uncovered something that's been > a problem for the whole time. :) >=20 > Specifically, "no, GUP should not be setting folios nor pages > dirty", because that generally needs to be done as part of a > filesystem > coordinated set of steps. If the page is dirty, and the filesystem > didn't expect it to be, that leads to problems. >=20 > This is part of the big, remaining set of required fixes, that > launched the creation of pin_user_pages*() and related. Connecting > up the filesystems properly is yet to be done. And until then, this > is a real defect. >=20 Not just filesystems. I found about two dozen places where drivers fail to mark a page dirty after writing to it, after obtaining the page from GUP. I'll get out patches for that, unless there's some reason I shouldn't. --=20 All Rights Reversed.