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See http://www.infradead.org/rpr.html X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 471082001A X-Stat-Signature: ckdenw738ok3eppkdpymcmywtd8c6ckt X-HE-Tag: 1689830489-256965 X-HE-Meta: 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 ru9NySKB aSGJsniGzs+TQXdPMbK3CQLa2CvlwSYaZuFzTdVCZdibE4aRAeO8I4MqP1LiSktyhSTc0Otb7Qdul8Evv+NoA0jJD93/h0vXY1rJ+T89bkO8L1dLbO/rfUkXs1p7rN/NVHAvlA8bK5axutxz9BohQsli9lcjC+9zNdU694OiTC1TdKgXGVQZACgLZASZ4xNESUXj6R0hbmS6xxx/qb1MZp6Zfqxk2ntTN8DIWAmepJ/uNTSHByCrYsTl8SJopnj5pBPw2GJoNH3J9dL2jCmqMNAiGhzJ9x2RJzzRGdLn9O5zk7E/ZEQ2UzH0BV5ioRqoGe5r69i6RwEcK9JWWidpa8U3Uqm4B/3WI7kXtXz8N1DACwDGGxFkQZLUohinWDeXZS3wX8EAutaOv3wcFoF3eZ+yTXFrnQiy9bM4Tih4cR+/xArS3RRYj5hQo1A== 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: On Tue, Jul 18, 2023 at 05:16:15PM +0100, Matthew Wilcox wrote: > How does _this_ folio end up in btrfs's write_dev_supers()? This is a > swap read. The only folios which are swapped are anonymous and tmpfs. > btrfs takes care of doing its own I/O. wait_dev_supers() is looking > for the error set in btrfs_end_super_write() which is the completion > routine for write_dev_supers(). The pages involved there are attached > to a btrfs address_space, not shmem or anon. It actually operates on the block_device inode. That does not matter for this series, but complicates things in other ways.