From nobody Thu Sep 19 17:08:49 2024 Received: from mout-p-202.mailbox.org (mout-p-202.mailbox.org [80.241.56.172]) (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 84E5A1CF283; Thu, 22 Aug 2024 13:51:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724334670; cv=none; b=EqGmW9o/Eudy7/lHswul+ZLwNC0kC5sQ3qa7ev4rwtBV0RNHtvD/wcy9MZ9xC9XaSfaLlXF/z0M0iBnp/GgSbfaVRLeMZCI/nCKCoFLHLM+x2EYr9FjIOLfEpWT6vI7+e9/wM67+pShf4XJUL/OBZZXZvKB+yJ+96DLLexpUAX0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724334670; c=relaxed/simple; bh=1iMLklpfB1/dfXOZRk1dLpcuJp8u6w+63r0ErS1kh7s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hiGqUdQzuvejGfCIPYS3On689itkTCBvrTiGvTJE4fZ+t1A0GGvCh5T1GzzkmPaR5uiemsc0qPKlruIEbWQ1zl69JwJ32rL40AJy2JAoyC6U3pqVlOls8EpcYFvEo9UfngcdLvtDmGeN8q8H3A27ucAEsNoS2N6Y0Jz3Szl383Q= 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=ZMob7FDY; arc=none smtp.client-ip=80.241.56.172 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="ZMob7FDY" 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-202.mailbox.org (Postfix) with ESMTPS id 4WqPjv43nRz9sny; Thu, 22 Aug 2024 15:50:59 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pankajraghav.com; s=MBO0001; t=1724334659; 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=pD3Ip9aPdQ9e51emhRiUmYHymg6Mc2qCEYPgRqwWlxo=; b=ZMob7FDYE+lhI6JG4HexlL05VAspa1JRUwCDmQRJj/A5r1kZWc4UD0yVvBjU/pAQZOh2ul O4SuqWb0onFo/HRZIvoPlMP/hDFZIOnijx18xKM6E3Hiz79nJMLtzjRCcuS5OmV0FH8iyl 3G8acOSnKK5HhZqRcf6qIzNjTVoQipNTYl0XBj5LXmucXWOg/Op0LW7hborfeVOeMmOpxk CA/8w6S+xRSq+OX2KQkQQR5arFkJxE+WRZZsZlqPH5FlRRVnHHs6sMmki+wDEzZ4YsIBMx FHJ7ktDsFE28pwe8KJds/Et3uhEi56dSEy0LldN5SWMwLLDBd7otktq+Vy6KAw== From: "Pankaj Raghav (Samsung)" To: brauner@kernel.org, akpm@linux-foundation.org Cc: chandan.babu@oracle.com, linux-fsdevel@vger.kernel.org, djwong@kernel.org, hare@suse.de, gost.dev@samsung.com, linux-xfs@vger.kernel.org, kernel@pankajraghav.com, hch@lst.de, david@fromorbit.com, Zi Yan , yang@os.amperecomputing.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, willy@infradead.org, john.g.garry@oracle.com, cl@os.amperecomputing.com, p.raghav@samsung.com, mcgrof@kernel.org, ryan.roberts@arm.com, Dave Chinner Subject: [PATCH v13 06/10] iomap: fix iomap_dio_zero() for fs bs > system page size Date: Thu, 22 Aug 2024 15:50:14 +0200 Message-ID: <20240822135018.1931258-7-kernel@pankajraghav.com> In-Reply-To: <20240822135018.1931258-1-kernel@pankajraghav.com> References: <20240822135018.1931258-1-kernel@pankajraghav.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 4WqPjv43nRz9sny Content-Type: text/plain; charset="utf-8" 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 Reviewed-by: Darrick J. Wong Reviewed-by: Dave Chinner --- fs/iomap/buffered-io.c | 4 ++-- fs/iomap/direct-io.c | 45 ++++++++++++++++++++++++++++++++++++------ 2 files changed, 41 insertions(+), 8 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 9b4ca3811a242..cdab801e9d635 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -2007,10 +2007,10 @@ iomap_writepages(struct address_space *mapping, str= uct writeback_control *wbc, } EXPORT_SYMBOL_GPL(iomap_writepages); =20 -static int __init iomap_init(void) +static int __init iomap_buffered_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_buffered_init); diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index f3b43d223a46e..c02b266bba525 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" =20 @@ -27,6 +28,13 @@ #define IOMAP_DIO_WRITE (1U << 30) #define IOMAP_DIO_DIRTY (1U << 31) =20 +/* + * Used for sub block zeroing in iomap_dio_zero() + */ +#define IOMAP_ZERO_PAGE_SIZE (SZ_64K) +#define IOMAP_ZERO_PAGE_ORDER (get_order(IOMAP_ZERO_PAGE_SIZE)) +static struct page *zero_page; + struct iomap_dio { struct kiocb *iocb; const struct iomap_dio_ops *dops; @@ -232,13 +240,20 @@ void iomap_dio_bio_end_io(struct bio *bio) } EXPORT_SYMBOL_GPL(iomap_dio_bio_end_io); =20 -static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio= *dio, +static int iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio = *dio, loff_t pos, unsigned len) { struct inode *inode =3D file_inode(dio->iocb->ki_filp); - struct page *page =3D ZERO_PAGE(0); struct bio *bio; =20 + if (!len) + return 0; + /* + * Max block size supported is 64k + */ + if (WARN_ON_ONCE(len > IOMAP_ZERO_PAGE_SIZE)) + return -EINVAL; + bio =3D iomap_dio_alloc_bio(iter, dio, 1, REQ_OP_WRITE | REQ_SYNC | REQ_I= DLE); fscrypt_set_bio_crypt_ctx(bio, inode, pos >> inode->i_blkbits, GFP_KERNEL); @@ -246,8 +261,9 @@ static void iomap_dio_zero(const struct iomap_iter *ite= r, struct iomap_dio *dio, bio->bi_private =3D dio; bio->bi_end_io =3D iomap_dio_bio_end_io; =20 - __bio_add_page(bio, page, len, 0); + __bio_add_page(bio, zero_page, len, 0); iomap_dio_submit_bio(iter, dio, bio, pos); + return 0; } =20 /* @@ -356,8 +372,10 @@ static loff_t iomap_dio_bio_iter(const struct iomap_it= er *iter, if (need_zeroout) { /* zero out from the start of the block to the write offset */ pad =3D pos & (fs_block_size - 1); - if (pad) - iomap_dio_zero(iter, dio, pos - pad, pad); + + ret =3D iomap_dio_zero(iter, dio, pos - pad, pad); + if (ret) + goto out; } =20 /* @@ -431,7 +449,8 @@ static loff_t iomap_dio_bio_iter(const struct iomap_ite= r *iter, /* zero out from the end of the write to the end of the block */ pad =3D pos & (fs_block_size - 1); if (pad) - iomap_dio_zero(iter, dio, pos, fs_block_size - pad); + ret =3D iomap_dio_zero(iter, dio, pos, + fs_block_size - pad); } out: /* Undo iter limitation to current extent */ @@ -753,3 +772,17 @@ 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 =3D alloc_pages(GFP_KERNEL | __GFP_ZERO, + IOMAP_ZERO_PAGE_ORDER); + + if (!zero_page) + return -ENOMEM; + + set_memory_ro((unsigned long)page_address(zero_page), + 1U << IOMAP_ZERO_PAGE_ORDER); + return 0; +} +fs_initcall(iomap_dio_init); --=20 2.44.1