From patchwork Tue Jun 25 11:44:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Pankaj Raghav (Samsung)" X-Patchwork-Id: 13710913 Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [80.241.56.151]) (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 3B9C8158D97; Tue, 25 Jun 2024 11:44:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.151 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719315894; cv=none; b=EVEFOpnDfSkLcKEd/kw8gVzP5/QJOZXzZHYpCNt6nLsN0+kkGKzDP6fCdSh95mut1ak9cnls2Zt+11SaMFwHuZi72bg6XShMemzGBk8zxjK5JLJrQdwkCc+OYBuxTAlUoeUy2MO3GbZyI6cVV2Ya/YTyD+bhO5ocOhKHuvmG4B4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719315894; c=relaxed/simple; bh=dahxj9t82JTs+MyYsEIrMf5G/C0MTlB+7yj6zoRqBuM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CIjGLV626PwvbKXhSz0++DjS2VMDWt1pXxgrmn8nfMyDP3BVSKOMVqW+WC5w5NnD3M5v0AnJUaWnVZRRPaZigbu2qRxwB2mozAl7oYApAI3wUHGr5tCdwV/LXkqfZGMZubD2RuQsoLHaKOhSQYmLdd20U6DTibT4w3cYJ9IkHyY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pankajraghav.com; spf=pass smtp.mailfrom=pankajraghav.com; dkim=pass (2048-bit key) header.d=pankajraghav.com header.i=@pankajraghav.com header.b=0cMOTi7n; arc=none smtp.client-ip=80.241.56.151 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pankajraghav.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pankajraghav.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=pankajraghav.com header.i=@pankajraghav.com header.b="0cMOTi7n" Received: from smtp2.mailbox.org (smtp2.mailbox.org [IPv6:2001:67c:2050:b231:465::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4W7jg46VmYz9srB; Tue, 25 Jun 2024 13:44:48 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pankajraghav.com; s=MBO0001; t=1719315888; h=from:from:reply-to:subject:subject: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=Df5ZWch5fTpYhlPxb9yx/HDWdwemGo64pl9vSh29I64=; b=0cMOTi7n0+bdIMypet/TOlug5hdj2GY0J3E8OdTB3YdQViT4ac5M8lASCbutH2h880yREb tDEJPZXkCWLc5f5xi939GQJiOTTFwOzK8RiPXTtOPaQUEwJo4T1XHrpuXme0gWrsaiYiM5 mzVvtZ0g5bpklzaTG3OhLBLLuh+hOmD7UDtC0KxOxJbCB5drbeB11NDM+OOcsB4zsv7QYS wntij5YskAvs78MC+oNNtEZHdKqobtc7gd+mWqvcyAsVNeUcyP8RWJsF8xBBL6G7xrivsc 9pk+zuB0Rztwcxm7L5xVShD0/TlZjTuyzaSak7c+rjdmP+RNJDoRAS1m7c4uYw== From: "Pankaj Raghav (Samsung)" To: david@fromorbit.com, willy@infradead.org, chandan.babu@oracle.com, djwong@kernel.org, brauner@kernel.org, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, yang@os.amperecomputing.com, linux-mm@kvack.org, john.g.garry@oracle.com, linux-fsdevel@vger.kernel.org, hare@suse.de, p.raghav@samsung.com, mcgrof@kernel.org, gost.dev@samsung.com, cl@os.amperecomputing.com, linux-xfs@vger.kernel.org, kernel@pankajraghav.com, hch@lst.de, Zi Yan Subject: [PATCH v8 06/10] iomap: fix iomap_dio_zero() for fs bs > system page size Date: Tue, 25 Jun 2024 11:44:16 +0000 Message-ID: <20240625114420.719014-7-kernel@pankajraghav.com> In-Reply-To: <20240625114420.719014-1-kernel@pankajraghav.com> References: <20240625114420.719014-1-kernel@pankajraghav.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Queue-Id: 4W7jg46VmYz9srB From: Pankaj Raghav iomap_dio_zero() will pad a fs block with zeroes if the direct IO size < fs block size. iomap_dio_zero() has an implicit assumption that fs block size < page_size. This is true for most filesystems at the moment. If the block size > page size, this will send the contents of the page next to zero page(as len > PAGE_SIZE) to the underlying block device, causing FS corruption. iomap is a generic infrastructure and it should not make any assumptions about the fs block size and the page size of the system. Signed-off-by: Pankaj Raghav Reviewed-by: Hannes Reinecke --- fs/iomap/buffered-io.c | 4 ++-- fs/iomap/direct-io.c | 30 ++++++++++++++++++++++++++++-- 2 files changed, 30 insertions(+), 4 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index f420c53d86ac..9a9e94c7ed1d 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -2007,10 +2007,10 @@ iomap_writepages(struct address_space *mapping, struct writeback_control *wbc, } EXPORT_SYMBOL_GPL(iomap_writepages); -static int __init iomap_init(void) +static int __init iomap_pagecache_init(void) { return bioset_init(&iomap_ioend_bioset, 4 * (PAGE_SIZE / SECTOR_SIZE), offsetof(struct iomap_ioend, io_bio), BIOSET_NEED_BVECS); } -fs_initcall(iomap_init); +fs_initcall(iomap_pagecache_init); diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index f3b43d223a46..61d09d2364f7 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include "trace.h" @@ -27,6 +28,13 @@ #define IOMAP_DIO_WRITE (1U << 30) #define IOMAP_DIO_DIRTY (1U << 31) +/* + * Used for sub block zeroing in iomap_dio_zero() + */ +#define ZERO_PAGE_64K_SIZE (65536) +#define ZERO_PAGE_64K_ORDER (get_order(ZERO_PAGE_64K_SIZE)) +static struct page *zero_page_64k; + struct iomap_dio { struct kiocb *iocb; const struct iomap_dio_ops *dops; @@ -236,9 +244,13 @@ static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio, loff_t pos, unsigned len) { struct inode *inode = file_inode(dio->iocb->ki_filp); - struct page *page = ZERO_PAGE(0); struct bio *bio; + /* + * Max block size supported is 64k + */ + WARN_ON_ONCE(len > ZERO_PAGE_64K_SIZE); + bio = iomap_dio_alloc_bio(iter, dio, 1, REQ_OP_WRITE | REQ_SYNC | REQ_IDLE); fscrypt_set_bio_crypt_ctx(bio, inode, pos >> inode->i_blkbits, GFP_KERNEL); @@ -246,7 +258,7 @@ static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio, bio->bi_private = dio; bio->bi_end_io = iomap_dio_bio_end_io; - __bio_add_page(bio, page, len, 0); + __bio_add_page(bio, zero_page_64k, len, 0); iomap_dio_submit_bio(iter, dio, bio, pos); } @@ -753,3 +765,17 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, return iomap_dio_complete(dio); } EXPORT_SYMBOL_GPL(iomap_dio_rw); + +static int __init iomap_dio_init(void) +{ + zero_page_64k = alloc_pages(GFP_KERNEL | __GFP_ZERO, + ZERO_PAGE_64K_ORDER); + + if (!zero_page_64k) + return -ENOMEM; + + set_memory_ro((unsigned long)page_address(zero_page_64k), + 1U << ZERO_PAGE_64K_ORDER); + return 0; +} +fs_initcall(iomap_dio_init);