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Aivazian" , Alexander Viro , Christian Brauner , Jan Kara , Namjae Jeon , Sungjong Seo , Yuezhang Mo , Dave Kleikamp , Ryusuke Konishi , Viacheslav Dubeyko , Konstantin Komarov , Bob Copeland Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, jfs-discussion@lists.sourceforge.net, linux-nilfs@vger.kernel.org, ntfs3@lists.linux.dev, linux-karma-devel@lists.sourceforge.net References: <20260218-blk-dontcache-v1-1-fad6675ef71f@columbia.edu> Content-Language: en-US From: Jens Axboe In-Reply-To: <20260218-blk-dontcache-v1-1-fad6675ef71f@columbia.edu> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/18/26 2:13 PM, Tal Zussman wrote: > Block device buffered reads and writes already pass through > filemap_read() and iomap_file_buffered_write() respectively, both of > which handle IOCB_DONTCACHE. Enable RWF_DONTCACHE for block device files > by setting FOP_DONTCACHE in def_blk_fops. > > For CONFIG_BUFFER_HEAD paths, thread the kiocb through > block_write_begin() so that buffer_head-based I/O can use DONTCACHE > behavior as well. Callers without a kiocb context (e.g. nilfs2 recovery) > pass NULL, which preserves the existing behavior. > > This support is useful for databases that operate on raw block devices, > among other userspace applications. OOO right now so I'll take a real look when I'm back, but when I originally did this work, it's not the issue side that's the issue. It's the pruning done from completion context, and you need to ensure that's sane context for that (non-irq). -- Jens Axboe