From patchwork Wed Apr 2 14:59:57 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 14036133 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 0AABC23C8B7 for ; Wed, 2 Apr 2025 15:00:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743606022; cv=none; b=T1Wm3HP92GE+BY9qk702s7HbKpvp3kEZA4CbxwM0JktLLv9+avbcL0/zKrySJxBCu67OQhkcogVZk1Cjuat455DuWysIVj32hXESy5L/x/shx7F8SgytOc0BT9BTcnFs9wtAITnkezU9tUlQWH7JjWspofRjQi3vQPBKS7EeUdU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743606022; c=relaxed/simple; bh=4B5J3DbErcd8b+TW7oApS/pINXzPINo20RAUwfkDtPg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tnx84/Ok3mpII9J8bbx4AeGKMIzHn5mt9rz4xkNH3y1a5hvifi/gPAGJjvEeTOtV/ysgQ6/tUhPewXcYyE09CaQ7shKLPXzX+JKYZtpkvPO39FOpM1bUXNS3g77LdeSvIGNt2y0SD9Y2h0/hE4M3W0bgG/9Fi9ge5sj9VhrMn2U= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=R/MLFsPv; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="R/MLFsPv" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=5XW0b8o2GA0rXaRAcMoHAk0zi9Q3pqKKR/5ZrqK6isA=; b=R/MLFsPvz24ooXP3n2jFFdaQXS M3AdX4NhgWKE+Ldr9ttHKD8qgG5GZYrzl4HoldQmoxWhsTna7sbeqGeV85qzgdBMglKSZcZo/qhDL 27mzrVxCjQJEvMLyNxePILgRc7e8EX9LjIZsx1RTe7+xFO4/WYXtZfFZp9QtaI2kspbnodfP3P44a fbnLduvq4PVvMS9Ka/aw11jUuI7aHj0yslB/pG7B/3rc6DfE161Izl44/4miE8Y+4cy2i60FQ4eM2 SOmtlICqt4DAxV3OBU6XtQ/ljD0WkgGJMiiWXQ4KH10ZgdKRajR1ONKHvVArn/PYczuOaMxhaNYYz gU7zsJJA==; Received: from willy by casper.infradead.org with local (Exim 4.98.1 #2 (Red Hat Linux)) id 1tzzZX-00000009gsB-18Xi; Wed, 02 Apr 2025 15:00:07 +0000 From: "Matthew Wilcox (Oracle)" To: linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , intel-gfx@lists.freedesktop.org, linux-mm@kvack.org, dri-devel@lists.freedesktop.org Subject: [PATCH v2 3/9] migrate: Remove call to ->writepage Date: Wed, 2 Apr 2025 15:59:57 +0100 Message-ID: <20250402150005.2309458-4-willy@infradead.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250402150005.2309458-1-willy@infradead.org> References: <20250402150005.2309458-1-willy@infradead.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The writepage callback is going away; filesystems must implement migrate_folio or else dirty folios will not be migratable. Signed-off-by: Matthew Wilcox (Oracle) --- mm/migrate.c | 60 ++++++---------------------------------------------- 1 file changed, 7 insertions(+), 53 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index f3ee6d8d5e2e..6e2488e5dbe4 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -944,67 +944,21 @@ int filemap_migrate_folio(struct address_space *mapping, } EXPORT_SYMBOL_GPL(filemap_migrate_folio); -/* - * Writeback a folio to clean the dirty state - */ -static int writeout(struct address_space *mapping, struct folio *folio) -{ - struct writeback_control wbc = { - .sync_mode = WB_SYNC_NONE, - .nr_to_write = 1, - .range_start = 0, - .range_end = LLONG_MAX, - .for_reclaim = 1 - }; - int rc; - - if (!mapping->a_ops->writepage) - /* No write method for the address space */ - return -EINVAL; - - if (!folio_clear_dirty_for_io(folio)) - /* Someone else already triggered a write */ - return -EAGAIN; - - /* - * A dirty folio may imply that the underlying filesystem has - * the folio on some queue. So the folio must be clean for - * migration. Writeout may mean we lose the lock and the - * folio state is no longer what we checked for earlier. - * At this point we know that the migration attempt cannot - * be successful. - */ - remove_migration_ptes(folio, folio, 0); - - rc = mapping->a_ops->writepage(&folio->page, &wbc); - - if (rc != AOP_WRITEPAGE_ACTIVATE) - /* unlocked. Relock */ - folio_lock(folio); - - return (rc < 0) ? -EIO : -EAGAIN; -} - /* * Default handling if a filesystem does not provide a migration function. */ static int fallback_migrate_folio(struct address_space *mapping, struct folio *dst, struct folio *src, enum migrate_mode mode) { - if (folio_test_dirty(src)) { - /* Only writeback folios in full synchronous migration */ - switch (mode) { - case MIGRATE_SYNC: - break; - default: - return -EBUSY; - } - return writeout(mapping, src); - } + WARN_ONCE(mapping->a_ops->writepages, + "%ps does not implement migrate_folio\n", + mapping->a_ops); + if (folio_test_dirty(src)) + return -EBUSY; /* - * Buffers may be managed in a filesystem specific way. - * We must have no buffers or drop them. + * Filesystem may have private data at folio->private that we + * can't migrate automatically. */ if (!filemap_release_folio(src, GFP_KERNEL)) return mode == MIGRATE_SYNC ? -EAGAIN : -EBUSY;