From mboxrd@z Thu Jan 1 00:00:00 1970 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3BC57C43458 for ; Mon, 6 Jul 2026 13:23:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 181596B00A1; Mon, 6 Jul 2026 09:23:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 15B436B00C7; Mon, 6 Jul 2026 09:23:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 098926B00C8; Mon, 6 Jul 2026 09:23:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id D22966B00A1 for ; Mon, 6 Jul 2026 09:23:04 -0400 (EDT) Received: from smtpin22.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 57E72A03F0 for ; Mon, 6 Jul 2026 13:23:04 +0000 (UTC) X-FDA: 84958417488.22.E6E1CEA Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf13.hostedemail.com (Postfix) with ESMTP id 47DDD2000C for ; Mon, 6 Jul 2026 13:23:02 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=xOdOZcGn; dmarc=fail reason="No valid SPF, DKIM not aligned (relaxed)" header.from=lst.de (policy=none); spf=none (imf13.hostedemail.com: domain of BATV+434a720473ee9d4dc2a2+8352+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+434a720473ee9d4dc2a2+8352+infradead.org+hch@bombadil.srs.infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1783344182; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=5zN02G99JNTm9pHnWNHPaR3ZvGKPUGfg3ofGB0irAKA=; b=VG0JzTMvw0SiGSYWXXCWgCc+OXKpQKGArB2AzWw3UrmxOEut2l+g/HmI7aiI+F+IpTUFL7 xsSVZrsLiQRszmxYxd3isNSx4FsL0rIgRCy0AeKihpaKQ+ApIhaUQr1CO9NaCYAgRNtyeY diYi3cz3vuzkNS6O1db5Rw2yQR2B85k= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=xOdOZcGn; dmarc=fail reason="No valid SPF, DKIM not aligned (relaxed)" header.from=lst.de (policy=none); spf=none (imf13.hostedemail.com: domain of BATV+434a720473ee9d4dc2a2+8352+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+434a720473ee9d4dc2a2+8352+infradead.org+hch@bombadil.srs.infradead.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1783344182; b=y+Ehg2kHmqvEvVIYMCnLx9ZPsKvrqUBGRUUC6JWlCeaxqhlq4PehVFa7sPbjAkb9sZCRrC /uNHLKv0LmTWWIlcxVTuF3olP51lVxroMwCxprbsu5JY5K0xlM7owDkl0Db/+HRoDXwnpY lvmI8TWOEIKYahskW3/9vE6aGKFV7Ko= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=5zN02G99JNTm9pHnWNHPaR3ZvGKPUGfg3ofGB0irAKA=; b=xOdOZcGn+HlbYLSz6s0ftbU9aR LbhKhNDa7DTwCH2ws1FFJlIXhP6WH0viHNrC44P0w1HO9ddjR9tvHwkX0ptiMEc1nh1vvZR3HfbrQ Lkhw2uGGcXq8+0+OVwk2SWcuj/FIZU9IB1XTZx1wsCAM6BzPAaQaElFRTrVTvnplX5ZvnQRVFqGwG VvhfPM2UwuQPnVB0CJdE3rkN/Qea195o7IL8iOFvyJYeoIrcr32K5Y2x9injiO+ZrPsGtcnzBsvzE k9Yv+fejYJoasCLWcol49TIXAmXhKFIhPnqN2C7Uia+FXw7sF8qOKh09x8mmM/PtvJsbeUkfk1xaX S9XU5LeA==; Received: from [89.144.223.34] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.99.1 #2 (Red Hat Linux)) id 1wgjHi-0000000Cad6-2jGl; Mon, 06 Jul 2026 13:22:56 +0000 From: Christoph Hellwig To: Cc: baoquan.he@linux.dev, akpm@linux-foundation.org, chrisl@kernel.org, usama.arif@linux.dev, kasong@tencent.com, nphamcs@gmail.com, shikemeng@huaweicloud.com, youngjun.park@lge.com, linux-mm@kvack.org Subject: [PATCH 5/7] mm/swap: use swap_ops to register swap device's methods Date: Mon, 6 Jul 2026 15:21:57 +0200 Message-ID: <20260706132206.935272-6-hch@lst.de> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260706132206.935272-1-hch@lst.de> References: <20260706132206.935272-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Stat-Signature: tzfebrsz5hfiopff9hxeki5ezzd46wpq X-Rspamd-Queue-Id: 47DDD2000C X-Rspamd-Server: rspam01 X-Rspam-User: X-HE-Tag: 1783344182-850837 X-HE-Meta: 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 KkReVE64 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: This simplifies codes and makes logic clearer. And also makes later any new swap device type being added easier to handle. Currently there are two types of swap devices: fs and bdev. Suggested-by: Chris Li Signed-off-by: Baoquan He [hch: updated for the new submit and can_merge abstraction] Signed-off-by: Christoph Hellwig Reviewed-by: Nhat Pham --- include/linux/swap.h | 1 + mm/page_io.c | 68 ++++++++++++++++++++++++++++---------------- mm/swap.h | 10 +++++++ mm/swapfile.c | 4 +++ 4 files changed, 58 insertions(+), 25 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 8f0f68e245ba..74ceb7a88fd5 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -282,6 +282,7 @@ struct swap_info_struct { struct work_struct reclaim_work; /* reclaim worker */ struct list_head discard_clusters; /* discard clusters list */ struct plist_node avail_list; /* entry in swap_avail_head */ + const struct swap_ops *ops; }; static inline swp_entry_t page_swap_entry(struct page *page) diff --git a/mm/page_io.c b/mm/page_io.c index 6009f6991b73..d2b11db1a57f 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -333,21 +333,7 @@ static bool swap_can_merge(struct swap_io_ctx *ctx, struct folio *folio, if (ctx->sis != sis) return false; - - if (sis->flags & SWP_FS_OPS) { - if (swap_dev_pos(folio->swap) != - swap_dev_pos(prev_folio->swap) + prev_folio_size) - return false; - } else { - if (swap_folio_sector(folio) != - swap_folio_sector(prev_folio) + - (prev_folio_size >> SECTOR_SHIFT)) - return false; - if (rw == WRITE && !folio_blkg_can_merge(folio, prev_folio)) - return false; - } - - return true; + return sis->ops->can_merge(folio, prev_folio, prev_folio_size, rw); } static void swap_add_folio(struct swap_io_ctx *ctx, struct folio *folio, int rw) @@ -645,6 +631,23 @@ static void swap_bdev_submit_read(struct swap_io_ctx *ctx) } } +static bool swap_bdev_can_merge(struct folio *folio, struct folio *prev_folio, + size_t prev_folio_size, int rw) +{ + if (swap_folio_sector(folio) != + swap_folio_sector(prev_folio) + (prev_folio_size >> SECTOR_SHIFT)) + return false; + if (rw == WRITE && !folio_blkg_can_merge(folio, prev_folio)) + return false; + return true; +} + +const struct swap_ops swap_bdev_ops = { + .submit_write = swap_bdev_submit_write, + .submit_read = swap_bdev_submit_read, + .can_merge = swap_bdev_can_merge, +}; + static void swap_fs_submit(struct swap_io_ctx *ctx, int rw) { struct swap_iocb *sio = ctx->sio; @@ -665,15 +668,34 @@ static void swap_fs_submit(struct swap_io_ctx *ctx, int rw) sio->iocb.ki_complete(&sio->iocb, ret); } +static void swap_fs_submit_write(struct swap_io_ctx *ctx) +{ + swap_fs_submit(ctx, WRITE); +} + +static void swap_fs_submit_read(struct swap_io_ctx *ctx) +{ + swap_fs_submit(ctx, READ); +} + +static bool swap_fs_can_merge(struct folio *folio, struct folio *prev_folio, + size_t prev_folio_size, int rw) +{ + return swap_dev_pos(folio->swap) == + swap_dev_pos(prev_folio->swap) + prev_folio_size; +} + +const struct swap_ops swap_fs_ops = { + .submit_write = swap_fs_submit_write, + .submit_read = swap_fs_submit_read, + .can_merge = swap_fs_can_merge, +}; + void swap_write_submit(struct swap_io_ctx *ctx) { if (!ctx->sio) return; - - if (ctx->sis->flags & SWP_FS_OPS) - swap_fs_submit(ctx, WRITE); - else - swap_bdev_submit_write(ctx); + ctx->sis->ops->submit_write(ctx); ctx->sio = NULL; ctx->sis = NULL; } @@ -682,11 +704,7 @@ void swap_read_submit(struct swap_io_ctx *ctx) { if (!ctx->sio) return; - - if (ctx->sis->flags & SWP_FS_OPS) - swap_fs_submit(ctx, READ); - else - swap_bdev_submit_read(ctx); + ctx->sis->ops->submit_read(ctx); ctx->sio = NULL; ctx->sis = NULL; } diff --git a/mm/swap.h b/mm/swap.h index b6ba80c2afb0..5119feff0e93 100644 --- a/mm/swap.h +++ b/mm/swap.h @@ -84,6 +84,13 @@ struct swap_io_ctx { struct swap_info_struct *sis; }; +struct swap_ops { + bool (*can_merge)(struct folio *folio, struct folio *prev_folio, + size_t prev_folio_size, int rw); + void (*submit_write)(struct swap_io_ctx *ctx); + void (*submit_read)(struct swap_io_ctx *ctx); +}; + #ifdef CONFIG_SWAP #include /* for swp_offset */ #include /* for bio_end_io_t */ @@ -471,6 +478,9 @@ static inline unsigned int folio_swap_flags(struct folio *folio) #endif /* CONFIG_SWAP */ +extern const struct swap_ops swap_bdev_ops; +extern const struct swap_ops swap_fs_ops; + int shmem_writeout(struct swap_io_ctx *ctx, struct folio *folio, struct list_head *folio_list); diff --git a/mm/swapfile.c b/mm/swapfile.c index 1887df22bd1e..b291510813a6 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2945,6 +2945,8 @@ static int setup_swap_extents(struct swap_info_struct *sis, if (ret) return ret; + sis->ops = &swap_bdev_ops; + if (S_ISBLK(inode->i_mode)) { ret = add_swap_extent(sis, 0, sis->max, 0); *span = sis->pages; @@ -2955,6 +2957,8 @@ static int setup_swap_extents(struct swap_info_struct *sis, ret = mapping->a_ops->swap_activate(sis, swap_file, span); if (ret < 0) return ret; + if (sis->flags & SWP_FS_OPS) + sis->ops = &swap_fs_ops; sis->flags |= SWP_ACTIVATED; return ret; } -- 2.53.0