From patchwork Wed Aug 14 20:38:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13764098 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 7CA101D1F62 for ; Wed, 14 Aug 2024 20:42:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723668125; cv=none; b=l/0vW445VpAFur8lzUKCcS2z3BQE3A3j+Q33Ox2U0qSTOCeRjN78vQUujUi2jjYXYK/q3z9izzFSzW8SkwponR32H6kueoMbJ6HuJLBlLdDRlUfw2ELj+QYUxW0P+kIlIlFi49WhswnZEc5+ssea3ROk4hHQ05J0rLl05zlJgQA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723668125; c=relaxed/simple; bh=10bIVVx2jestpGK485TL9Ycw86ihAkhRIcLT5e38SVU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IvfTaR4WwemHsHFnDTl/X90FMLWfcF3irqMjf+oa4zjNV9SZJIK6hWCEoJv9BoM/BzsPNYb6Vlut+yxOD4oTMzC8XUJZi2ZtmBggigXVntOFtcSiSFSTi4q0dph+LRdgy2d0E8uRo7xPRKABysYlQ1OlWME+pBm1cD0xta7jUYg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=HRN0mQcA; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HRN0mQcA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1723668120; 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=iXFw+oU47qKVQiA+0YFU3Ycf5Gk6FAGXhwuof46YCCg=; b=HRN0mQcA50HKyY204oYv0rvtprGmEtV/x//tWxsTok+tUi1RmDCFTqmUVNeK/k2FOEsf2E TXEUBvqVv11G9wbwn8YGuD4hxe2m3UHttdVkta7Gd84VFaUQpaQ0bqULnnO8qHHDBk+xCo kkwlU1wEEZJBY2UC53TjM1BTR58vkRs= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-515-0YvQwBjyPzaCGwVpAix73g-1; Wed, 14 Aug 2024 16:41:57 -0400 X-MC-Unique: 0YvQwBjyPzaCGwVpAix73g-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C84201954B16; Wed, 14 Aug 2024 20:41:53 +0000 (UTC) Received: from warthog.procyon.org.uk.com (unknown [10.42.28.30]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 910B51955D88; Wed, 14 Aug 2024 20:41:47 +0000 (UTC) From: David Howells To: Christian Brauner , Steve French , Matthew Wilcox Cc: David Howells , Jeff Layton , Gao Xiang , Dominique Martinet , Marc Dionne , Paulo Alcantara , Shyam Prasad N , Tom Talpey , Eric Van Hensbergen , Ilya Dryomov , netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Steve French , Enzo Matsumiya Subject: [PATCH v2 23/25] cifs: Use iterate_and_advance*() routines directly for hashing Date: Wed, 14 Aug 2024 21:38:43 +0100 Message-ID: <20240814203850.2240469-24-dhowells@redhat.com> In-Reply-To: <20240814203850.2240469-1-dhowells@redhat.com> References: <20240814203850.2240469-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Replace the bespoke cifs iterators of ITER_BVEC and ITER_KVEC to do hashing with iterate_and_advance_kernel() - a variant on iterate_and_advance() that only supports kernel-internal ITER_* types and not UBUF/IOVEC types. The bespoke ITER_XARRAY is left because we don't really want to be calling crypto_shash_update() under the RCU read lock for large amounts of data; besides, ITER_XARRAY is going to be phased out. Signed-off-by: David Howells cc: Steve French cc: Paulo Alcantara cc: Tom Talpey cc: Enzo Matsumiya cc: linux-cifs@vger.kernel.org --- fs/smb/client/cifsencrypt.c | 109 ++++++++---------------------------- include/linux/iov_iter.h | 47 ++++++++++++++++ 2 files changed, 70 insertions(+), 86 deletions(-) diff --git a/fs/smb/client/cifsencrypt.c b/fs/smb/client/cifsencrypt.c index 6322f0f68a17..991a1ab047e7 100644 --- a/fs/smb/client/cifsencrypt.c +++ b/fs/smb/client/cifsencrypt.c @@ -21,82 +21,10 @@ #include #include #include +#include #include "../common/arc4.h" #include -/* - * Hash data from a BVEC-type iterator. - */ -static int cifs_shash_bvec(const struct iov_iter *iter, ssize_t maxsize, - struct shash_desc *shash) -{ - const struct bio_vec *bv = iter->bvec; - unsigned long start = iter->iov_offset; - unsigned int i; - void *p; - int ret; - - for (i = 0; i < iter->nr_segs; i++) { - size_t off, len; - - len = bv[i].bv_len; - if (start >= len) { - start -= len; - continue; - } - - len = min_t(size_t, maxsize, len - start); - off = bv[i].bv_offset + start; - - p = kmap_local_page(bv[i].bv_page); - ret = crypto_shash_update(shash, p + off, len); - kunmap_local(p); - if (ret < 0) - return ret; - - maxsize -= len; - if (maxsize <= 0) - break; - start = 0; - } - - return 0; -} - -/* - * Hash data from a KVEC-type iterator. - */ -static int cifs_shash_kvec(const struct iov_iter *iter, ssize_t maxsize, - struct shash_desc *shash) -{ - const struct kvec *kv = iter->kvec; - unsigned long start = iter->iov_offset; - unsigned int i; - int ret; - - for (i = 0; i < iter->nr_segs; i++) { - size_t len; - - len = kv[i].iov_len; - if (start >= len) { - start -= len; - continue; - } - - len = min_t(size_t, maxsize, len - start); - ret = crypto_shash_update(shash, kv[i].iov_base + start, len); - if (ret < 0) - return ret; - maxsize -= len; - - if (maxsize <= 0) - break; - start = 0; - } - - return 0; -} - /* * Hash data from an XARRAY-type iterator. */ @@ -145,27 +73,36 @@ static ssize_t cifs_shash_xarray(const struct iov_iter *iter, ssize_t maxsize, return 0; } +static size_t cifs_shash_step(void *iter_base, size_t progress, size_t len, + void *priv, void *priv2) +{ + struct shash_desc *shash = priv; + int ret, *pret = priv2; + + ret = crypto_shash_update(shash, iter_base, len); + if (ret < 0) { + *pret = ret; + return len; + } + return 0; +} + /* * Pass the data from an iterator into a hash. */ static int cifs_shash_iter(const struct iov_iter *iter, size_t maxsize, struct shash_desc *shash) { - if (maxsize == 0) - return 0; + struct iov_iter tmp_iter = *iter; + int err = -EIO; - switch (iov_iter_type(iter)) { - case ITER_BVEC: - return cifs_shash_bvec(iter, maxsize, shash); - case ITER_KVEC: - return cifs_shash_kvec(iter, maxsize, shash); - case ITER_XARRAY: + if (iov_iter_type(iter) == ITER_XARRAY) return cifs_shash_xarray(iter, maxsize, shash); - default: - pr_err("cifs_shash_iter(%u) unsupported\n", iov_iter_type(iter)); - WARN_ON_ONCE(1); - return -EIO; - } + + if (iterate_and_advance_kernel(&tmp_iter, maxsize, shash, &err, + cifs_shash_step) != maxsize) + return err; + return 0; } int __cifs_calc_signature(struct smb_rqst *rqst, diff --git a/include/linux/iov_iter.h b/include/linux/iov_iter.h index a223370a59a7..c4aa58032faf 100644 --- a/include/linux/iov_iter.h +++ b/include/linux/iov_iter.h @@ -328,4 +328,51 @@ size_t iterate_and_advance(struct iov_iter *iter, size_t len, void *priv, return iterate_and_advance2(iter, len, priv, NULL, ustep, step); } +/** + * iterate_and_advance_kernel - Iterate over a kernel-internal iterator + * @iter: The iterator to iterate over. + * @len: The amount to iterate over. + * @priv: Data for the step functions. + * @priv2: More data for the step functions. + * @step: Function for other iterators; given kernel addresses. + * + * Iterate over the next part of an iterator, up to the specified length. The + * buffer is presented in segments, which for kernel iteration are broken up by + * physical pages and mapped, with the mapped address being presented. + * + * [!] Note This will only handle BVEC, KVEC, FOLIOQ, XARRAY and DISCARD-type + * iterators; it will not handle UBUF or IOVEC-type iterators. + * + * A step functions, @step, must be provided, one for handling mapped kernel + * addresses and the other is given user addresses which have the potential to + * fault since no pinning is performed. + * + * The step functions are passed the address and length of the segment, @priv, + * @priv2 and the amount of data so far iterated over (which can, for example, + * be added to @priv to point to the right part of a second buffer). The step + * functions should return the amount of the segment they didn't process (ie. 0 + * indicates complete processsing). + * + * This function returns the amount of data processed (ie. 0 means nothing was + * processed and the value of @len means processes to completion). + */ +static __always_inline +size_t iterate_and_advance_kernel(struct iov_iter *iter, size_t len, void *priv, + void *priv2, iov_step_f step) +{ + if (unlikely(iter->count < len)) + len = iter->count; + if (unlikely(!len)) + return 0; + if (iov_iter_is_bvec(iter)) + return iterate_bvec(iter, len, priv, priv2, step); + if (iov_iter_is_kvec(iter)) + return iterate_kvec(iter, len, priv, priv2, step); + if (iov_iter_is_folioq(iter)) + return iterate_folioq(iter, len, priv, priv2, step); + if (iov_iter_is_xarray(iter)) + return iterate_xarray(iter, len, priv, priv2, step); + return iterate_discard(iter, len, priv, priv2, step); +} + #endif /* _LINUX_IOV_ITER_H */