From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0D4E32E1C69; Wed, 13 Aug 2025 12:44:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755089054; cv=none; b=qSJf2l7WCpDrKXTigH8Z/RAmZss9NF3Ox4Yp22x+osJyf3K980dgI4xtUJEotQddRA8djlmdvnSNvU6rNDxLUjtnL9QS68mv3CJGIVh6qGhRLf7rWvfca6CeT0gdsLDEkmbbEX8U4gifrpk5y+cwKtVfS5WCeWepFVV9ts6LEQA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755089054; c=relaxed/simple; bh=DDRdKzPeZcrqxhyOyBHNrCzLGb9zvR9HWqXptkScBTI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=gdY/Ju0zfsrh2Yd55m05hZSeTy7kbBzTZrzacX9yq5obT5PchtZPudtFiJZgl4YUy1n5Ygd+Ai2PP8b73dCIDCzwkFYt2KYfr4qY67KieUaRLSf/gWvwvgDTPCicVP5kX422fEFgSmwb11DNpTd5o5JzUWggNZ1bqf6StSzsAJs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gYls+iQY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gYls+iQY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98A6DC4CEEB; Wed, 13 Aug 2025 12:44:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755089053; bh=DDRdKzPeZcrqxhyOyBHNrCzLGb9zvR9HWqXptkScBTI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=gYls+iQY+eTb+KNGGeRqRwXWo8twVx/emg3S4y0UYygbM5zO9NqHkKOoMf8oqlqlP i5BoF7JCGyiO+dNBV43VNf06FoblMmDnfeIMsiezUIzZfEQos0MK5yNU6enaGQAXPc tCsL8SK1kvYsw8aimFXHiMMAwSGXX7LDT6+1+LkNShDaUxJ3nYokKDBO3d9YFW2t7o c9QlpPdguBGmx0nGMIzgIleVjk+S5361TxR74ppc2b/6EXawl7CJnZvFXZFEEbfHCx gh4FPANJ/YJ8GX/Ep0bKAQ87CTUUl2M23ZDqJXJIS3hCTlslAYG8KhB50nLC1O2H22 coJJM4BNYO67w== From: Pratyush Yadav To: Pasha Tatashin Cc: pratyush@kernel.org, jasonmiu@google.com, graf@amazon.com, changyuanl@google.com, rppt@kernel.org, dmatlack@google.com, rientjes@google.com, corbet@lwn.net, rdunlap@infradead.org, ilpo.jarvinen@linux.intel.com, kanie@linux.alibaba.com, ojeda@kernel.org, aliceryhl@google.com, masahiroy@kernel.org, akpm@linux-foundation.org, tj@kernel.org, yoann.congal@smile.fr, mmaurer@google.com, roman.gushchin@linux.dev, chenridong@huawei.com, axboe@kernel.dk, mark.rutland@arm.com, jannh@google.com, vincent.guittot@linaro.org, hannes@cmpxchg.org, dan.j.williams@intel.com, david@redhat.com, joel.granados@kernel.org, rostedt@goodmis.org, anna.schumaker@oracle.com, song@kernel.org, zhangguopeng@kylinos.cn, linux@weissschuh.net, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, gregkh@linuxfoundation.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, rafael@kernel.org, dakr@kernel.org, bartosz.golaszewski@linaro.org, cw00.choi@samsung.com, myungjoo.ham@samsung.com, yesanishhere@gmail.com, Jonathan.Cameron@huawei.com, quic_zijuhu@quicinc.com, aleksander.lobakin@intel.com, ira.weiny@intel.com, andriy.shevchenko@linux.intel.com, leon@kernel.org, lukas@wunner.de, bhelgaas@google.com, wagi@kernel.org, djeffery@redhat.com, stuart.w.hayes@gmail.com, lennart@poettering.net, brauner@kernel.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, saeedm@nvidia.com, ajayachandra@nvidia.com, jgg@nvidia.com, parav@nvidia.com, leonro@nvidia.com, witu@nvidia.com, jrhilke@google.com Subject: Re: [PATCH v3 29/30] luo: allow preserving memfd In-Reply-To: References: <20250807014442.3829950-1-pasha.tatashin@soleen.com> <20250807014442.3829950-30-pasha.tatashin@soleen.com> Date: Wed, 13 Aug 2025 14:44:03 +0200 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Fri, Aug 08 2025, Pasha Tatashin wrote: >> +static int memfd_luo_preserve_folios(struct memfd_luo_preserved_folio *pfolios, >> + struct folio **folios, >> + unsigned int nr_folios) >> +{ >> + unsigned int i; > > Should be 'long i' > > Otherwise in err_unpreserve we get into an infinite loop. Thank you > Josh Hilke for noticing this. Good catch! Will fix. > >> + int err; >> + >> + for (i = 0; i < nr_folios; i++) { >> + struct memfd_luo_preserved_folio *pfolio = &pfolios[i]; >> + struct folio *folio = folios[i]; >> + unsigned int flags = 0; >> + unsigned long pfn; >> + >> + err = kho_preserve_folio(folio); >> + if (err) >> + goto err_unpreserve; >> + >> + pfn = folio_pfn(folio); >> + if (folio_test_dirty(folio)) >> + flags |= PRESERVED_FLAG_DIRTY; >> + if (folio_test_uptodate(folio)) >> + flags |= PRESERVED_FLAG_UPTODATE; >> + >> + pfolio->foliodesc = PRESERVED_FOLIO_MKDESC(pfn, flags); >> + pfolio->index = folio->index; >> + } >> + >> + return 0; >> + >> +err_unpreserve: >> + i--; >> + for (; i >= 0; i--) >> + WARN_ON_ONCE(kho_unpreserve_folio(folios[i])); >> + return err; >> +} >> + -- Regards, Pratyush Yadav