From patchwork Mon Sep 18 11:05:07 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 13389471 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 970E1CD3434 for ; Mon, 18 Sep 2023 11:06:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241271AbjIRLGF (ORCPT ); Mon, 18 Sep 2023 07:06:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58388 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237146AbjIRLF1 (ORCPT ); Mon, 18 Sep 2023 07:05:27 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D358C3; Mon, 18 Sep 2023 04:05:21 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 8D3271FE01; Mon, 18 Sep 2023 11:05:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1695035117; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BVPahaNIXwTpL/pMoLNSBcQ3X6Y5CcM2ahaMzcXgzso=; b=OVz6NWhpbR0q0OZZ1jpe84PjWI4R5DxCDX97ryr4BxU55E++YPrOTU0eeWImxbZ2GIMGey FA4LXWd2Eowowu626PVwcvwRek+GTTlQCNA4E89LYV06t0sIHN1MqSTtlkJkeUY0oain5N d4r/B1A+KSW4+LOBUd2eeSDahbz1Hm0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1695035117; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BVPahaNIXwTpL/pMoLNSBcQ3X6Y5CcM2ahaMzcXgzso=; b=f8Uy+m+oyJYVe5iQbmdeBTEF4CixVkmkwM4vuEMvktls1jPhVvGn/eWStGZfy097JYLXyv wdRTDi6zLS5OUeAw== Received: from adalid.arch.suse.de (adalid.arch.suse.de [10.161.8.13]) by relay2.suse.de (Postfix) with ESMTP id 7739F2C165; Mon, 18 Sep 2023 11:05:17 +0000 (UTC) Received: by adalid.arch.suse.de (Postfix, from userid 16045) id 6411251CD15B; Mon, 18 Sep 2023 13:05:17 +0200 (CEST) From: Hannes Reinecke To: Matthew Wilcox Cc: Luis Chamberlain , Christoph Hellwig , Jens Axboe , Pankaj Raghav , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, Hannes Reinecke Subject: [PATCH 15/18] brd: make sector size configurable Date: Mon, 18 Sep 2023 13:05:07 +0200 Message-Id: <20230918110510.66470-16-hare@suse.de> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20230918110510.66470-1-hare@suse.de> References: <20230918110510.66470-1-hare@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Add a module option 'rd_blksize' to allow the user to change the sector size of the RAM disks. Signed-off-by: Hannes Reinecke --- drivers/block/brd.c | 50 +++++++++++++++++++++++++++++++-------------- 1 file changed, 35 insertions(+), 15 deletions(-) diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 90e1b6c4fbc8..0c5f3dbbb77c 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -30,7 +30,7 @@ /* * Each block ramdisk device has a xarray of folios that stores the folios * containing the block device's contents. A brd folio's ->index is its offset - * in PAGE_SIZE units. This is similar to, but in no way connected with, + * in brd_sector_size units. This is similar to, but in no way connected with, * the kernel's pagecache or buffer cache (which sit above our block device). */ struct brd_device { @@ -43,9 +43,11 @@ struct brd_device { */ struct xarray brd_folios; u64 brd_nr_folios; + unsigned int brd_sector_shift; + unsigned int brd_sector_size; }; -#define BRD_SECTOR_SHIFT(b) (PAGE_SHIFT - SECTOR_SHIFT) +#define BRD_SECTOR_SHIFT(b) ((b)->brd_sector_shift - SECTOR_SHIFT) static pgoff_t brd_sector_index(struct brd_device *brd, sector_t sector) { @@ -85,7 +87,7 @@ static int brd_insert_folio(struct brd_device *brd, sector_t sector, gfp_t gfp) { pgoff_t idx; struct folio *folio, *cur; - unsigned int rd_sector_order = get_order(PAGE_SIZE); + unsigned int rd_sector_order = get_order(brd->brd_sector_size); int ret = 0; folio = brd_lookup_folio(brd, sector); @@ -140,7 +142,7 @@ static void brd_free_folios(struct brd_device *brd) static int copy_to_brd_setup(struct brd_device *brd, sector_t sector, size_t n, gfp_t gfp) { - unsigned int rd_sector_size = PAGE_SIZE; + unsigned int rd_sector_size = brd->brd_sector_size; unsigned int offset = brd_sector_offset(brd, sector); size_t copy; int ret; @@ -163,7 +165,7 @@ static void copy_to_brd(struct brd_device *brd, const void *src, sector_t sector, size_t n) { struct folio *folio; - unsigned int rd_sector_size = PAGE_SIZE; + unsigned int rd_sector_size = brd->brd_sector_size; unsigned int offset = brd_sector_offset(brd, sector); size_t copy; @@ -181,7 +183,7 @@ static void copy_from_brd(void *dst, struct brd_device *brd, sector_t sector, size_t n) { struct folio *folio; - unsigned int rd_sector_size = PAGE_SIZE; + unsigned int rd_sector_size = brd->brd_sector_size; unsigned int offset = brd_sector_offset(brd, sector); size_t copy; @@ -279,6 +281,10 @@ static int max_part = 1; module_param(max_part, int, 0444); MODULE_PARM_DESC(max_part, "Num Minors to reserve between devices"); +static unsigned int rd_blksize = PAGE_SIZE; +module_param(rd_blksize, uint, 0444); +MODULE_PARM_DESC(rd_blksize, "Blocksize of each RAM disk in bytes."); + MODULE_LICENSE("GPL"); MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR); MODULE_ALIAS("rd"); @@ -305,6 +311,7 @@ static int brd_alloc(int i) struct brd_device *brd; struct gendisk *disk; char buf[DISK_NAME_LEN]; + unsigned int rd_max_sectors; int err = -ENOMEM; list_for_each_entry(brd, &brd_devices, brd_list) @@ -315,6 +322,25 @@ static int brd_alloc(int i) return -ENOMEM; brd->brd_number = i; list_add_tail(&brd->brd_list, &brd_devices); + if (!is_power_of_2(rd_blksize)) { + pr_err("rd_blksize %d is not supported\n", rd_blksize); + err = -EINVAL; + goto out_free_dev; + } + if (rd_blksize < SECTOR_SIZE) { + pr_err("rd_blksize must be at least 512 bytes\n"); + err = -EINVAL; + goto out_free_dev; + } + /* We can't allocate more than MAX_ORDER pages */ + rd_max_sectors = (1ULL << MAX_ORDER) << PAGE_SECTORS_SHIFT; + if ((rd_blksize >> SECTOR_SHIFT) > rd_max_sectors) { + pr_err("rd_blocksize too large\n"); + err = -EINVAL; + goto out_free_dev; + } + brd->brd_sector_shift = ilog2(rd_blksize); + brd->brd_sector_size = rd_blksize; xa_init(&brd->brd_folios); @@ -334,15 +360,9 @@ static int brd_alloc(int i) disk->private_data = brd; strscpy(disk->disk_name, buf, DISK_NAME_LEN); set_capacity(disk, rd_size * 2); - - /* - * This is so fdisk will align partitions on 4k, because of - * direct_access API needing 4k alignment, returning a PFN - * (This is only a problem on very small devices <= 4M, - * otherwise fdisk will align on 1M. Regardless this call - * is harmless) - */ - blk_queue_physical_block_size(disk->queue, PAGE_SIZE); + + blk_queue_physical_block_size(disk->queue, rd_blksize); + blk_queue_max_hw_sectors(disk->queue, rd_max_sectors); /* Tell the block layer that this is not a rotational device */ blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue);