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b=pJW9ARe4+Ypc2ChSzh8mz+TprpwYAZj5zGT+0miopyp0ySvTq18CVxdDIU+BsRCDV //K1GVsbt86tjLcH96Ou+iIn5iR4wLzECocuYwg81tMQTIy69bQcDldHudVaCSSxZ6 4sFkrxYYf4xS3+pUt7lrlxW/EDwgXKQ5JKbKNU2/EsTK6kfZcW8wkOqp7qXoOu1N5K uTKJ5tKd82lMUKNg8JiKnUx8tgCSNKR55xE5sQ0xXtKPltvTF2MaTPn2AW1f5hDH19 Kv17nUpiXa7NrKkjEnG/6ptPBxUxhxq2vfjhGoJSCbv5h00vl+Fi5qd9grt9Lo1fvI XDUnKDXc2BUZg== Date: Sun, 25 Feb 2024 21:50:30 -0500 From: Al Viro To: Linus Torvalds Cc: Kent Overstreet , Matthew Wilcox , Luis Chamberlain , lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-mm , Daniel Gomez , Pankaj Raghav , Jens Axboe , Dave Chinner , Christoph Hellwig , Chris Mason , Johannes Weiner Subject: Re: [LSF/MM/BPF TOPIC] Measuring limits and enhancing buffered IO Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: D2C5C1A0006 X-Stat-Signature: jpdry97qwex19dxrz4kmxfzp6mdhkbya X-HE-Tag: 1708915762-58616 X-HE-Meta: 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 L4eS2/7c JDcRGo0+gtDV03XoOCQGIXjC0lKfcHMx76zPOYNKTEE7M0QPXFxLH0l3mSEVlrA+Rhft12mFYToRoilnHV+FvtwopExVXi1Ua9YCSycWPuZJkyuSyUhCqItx9bdGb/BbAeBk/CfgcWqxgHPiPGoXomxYhFg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, Feb 25, 2024 at 05:32:14PM -0800, Linus Torvalds wrote: > But to take a different example, ext2 just calls > generic_file_write_iter() *without* taking the inode lock, and does > locking one page at a time. As far as I know, nobody ever really > complained. Uh? __generic_file_write_iter() doesn't take inode lock, but generic_file_write_iter() does. O_APPEND handling aside, there's also file_remove_privs() in there and it does need that lock.