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Tue, 03 Jun 2025 06:10:20 -0700 (PDT) Message-ID: <24b9b367-d2ef-4eb5-ad56-f43ab624dd14@kernel.dk> Date: Tue, 3 Jun 2025 07:10:19 -0600 Precedence: bulk X-Mailing-List: linux-man@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: RWF_DONTCACHE documentation To: Johannes Thumshirn , "hch@infradead.org" Cc: "linux-fsdevel@vger.kernel.org" , "linux-man@vger.kernel.org" References: <12bb8614-a3e1-474e-914c-c06171f0a35e@wdc.com> Content-Language: en-US From: Jens Axboe In-Reply-To: <12bb8614-a3e1-474e-914c-c06171f0a35e@wdc.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/3/25 12:20 AM, Johannes Thumshirn wrote: > On 02.06.25 17:53, Jens Axboe wrote: >> On 6/2/25 9:00 AM, Christoph Hellwig wrote: >>> Hi Jens, >>> >>> I just tried to reference RWF_DONTCACHE semantics in a standards >>> discussion, but it doesn't seem to be documented in the man pages >>> or in fact anywhere else I could easily find. Could you please write >>> up the semantics for the preadv2/pwritev2 man page? >> >> Sure, I can write up something for the man page. >> > > Hi Jens, > > Small sidetrack here. What happened to the ext4 and btrfs support of > RWF_DONTCACHE? I remember seeing your series having ext4 and btrfs > support as well but in current master only xfs is setting FOP_DONTCACHE. The btrfs support got queued up, that's all I know on that front. For ext4, it needed a bit of a hack [1] and there was some chatter on converting the write side to iomap, which would eliminate the need for that hack. The last fs patches I had on top of the core bits was: https://git.kernel.dk/cgit/linux/log/?h=buffered-uncached-fs.11 in case you or someone else wants to pursue those parts. [1] https://git.kernel.dk/cgit/linux/commit/?h=buffered-uncached-fs.11&id=92df0ef308d0bfbbc26a7efa1d571a506fd8fee3 -- Jens Axboe