From patchwork Wed Apr 29 14:03:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martijn Coenen X-Patchwork-Id: 11517517 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 80E3292A for ; Wed, 29 Apr 2020 14:04:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6352F2082E for ; Wed, 29 Apr 2020 14:04:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=android.com header.i=@android.com header.b="CUy816SA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728138AbgD2OD7 (ORCPT ); Wed, 29 Apr 2020 10:03:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1728137AbgD2OD7 (ORCPT ); Wed, 29 Apr 2020 10:03:59 -0400 Received: from mail-wr1-x444.google.com (mail-wr1-x444.google.com [IPv6:2a00:1450:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 761B7C035493 for ; Wed, 29 Apr 2020 07:03:58 -0700 (PDT) Received: by mail-wr1-x444.google.com with SMTP id t14so2657211wrw.12 for ; Wed, 29 Apr 2020 07:03:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=android.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=WSTM3Qi/4U9iaA1lz8BvS/1iZyuC1rKHgcM75ldZEu4=; b=CUy816SARBoL3Uki3aIIhK4RmGONTtkFUicVkdJGwEY79gT7qkVdXYcuhkWVB7hMOP dWvfwllgHNLuEmmFhBvTQztCjHJPyzkVpBQwTAPZBJB7/akeF4Sldi2OQRO6ZX37f1Vd P7HTOFl1gKJZN8is5CoOkKHL7BhFkubDw+V0nNNa8LPi1bebKXNAPAdeqrUd8aL5awjR 9zG+o0v+2l0mOvQ8wsY0VJQhPbaEywfjlJU0sdx5fA7nW+sD2aFKBxdTC8Q8ItMmnWb0 OtIurjg7erO3sU910m+PEr/BLGEVYhIAF3tI/ONoxIXSHwyXMztfzoc5naQyKcxaXP7L +1sA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=WSTM3Qi/4U9iaA1lz8BvS/1iZyuC1rKHgcM75ldZEu4=; b=PslGpZeN4puMBXWBA3xjhVzg8+K/GYNW7y79M2sYpYgvWw8goqG54l8hoV8rviiF7K /ab2IudoKfzsGhLW0AWbkXdAVytTmOtMo7fVVNrwc/hEAMmRuOf9e26ZqeO/IrTLFE/N g/hNIMxluI47fFnvhnusGxivtFF/ye62svKda/EbmiDV0hHKy7jpFWo/tVyV9L+VziaD 2mDT1+CqIBP4KZsu3reuvF3yHHZxwz/9mf97hgmUc5Q6ZAETgw/xDUhOaxJlnxuys6v2 hu5D77j9+TsYOQkneH2YdCcF5806B8vc3JbXSMEbfSJu6e2rbVaOWQ7OhlBztqwVr7DO KUVA== X-Gm-Message-State: AGi0PuaOGixbc4xzL9S2z6heQaTyXJs3gmUDZzfvViC8yKAxl6+9alwA n2DIEdHSAv7jKPeyQx6UKnzZKg== X-Google-Smtp-Source: APiQypLh806kYCaic9QEG1Qzl0KzfPxn1oM3FQfGFXaXHMJCgdvQnOl9wOD92kYUKJ4GjvyTRpnrhQ== X-Received: by 2002:adf:fa04:: with SMTP id m4mr38662555wrr.30.1588169037163; Wed, 29 Apr 2020 07:03:57 -0700 (PDT) Received: from maco2.ams.corp.google.com (a83-162-234-235.adsl.xs4all.nl. [83.162.234.235]) by smtp.gmail.com with ESMTPSA id d133sm8887008wmc.27.2020.04.29.07.03.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Apr 2020 07:03:56 -0700 (PDT) From: Martijn Coenen To: axboe@kernel.dk, hch@lst.de, ming.lei@redhat.com Cc: narayan@google.com, zezeozue@google.com, kernel-team@android.com, maco@google.com, bvanassche@acm.org, Chaitanya.Kulkarni@wdc.com, jaegeuk@kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Martijn Coenen Subject: [PATCH v4 09/10] loop: Clean up LOOP_SET_STATUS lo_flags handling. Date: Wed, 29 Apr 2020 16:03:40 +0200 Message-Id: <20200429140341.13294-10-maco@android.com> X-Mailer: git-send-email 2.26.2.303.gf8c07b1a785-goog In-Reply-To: <20200429140341.13294-1-maco@android.com> References: <20200429140341.13294-1-maco@android.com> MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org LOOP_SET_STATUS(64) will actually allow some lo_flags to be modified; in particular, LO_FLAGS_AUTOCLEAR can be set and cleared, whereas LO_FLAGS_PARTSCAN can be set to request a partition scan. Make this explicit by updating the UAPI to include the flags that can be set/cleared using this ioctl. The implementation can then blindly take over the passed in flags, and use the previous flags for those flags that can't be set / cleared using LOOP_SET_STATUS. Signed-off-by: Martijn Coenen Reviewed-by: Christoph Hellwig --- drivers/block/loop.c | 19 +++++++++++++------ include/uapi/linux/loop.h | 10 ++++++++-- 2 files changed, 21 insertions(+), 8 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index f172a64333aa..cfbdd99fdb1a 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1049,9 +1049,7 @@ loop_set_status_from_info(struct loop_device *lo, lo->transfer = xfer->transfer; lo->ioctl = xfer->ioctl; - if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) != - (info->lo_flags & LO_FLAGS_AUTOCLEAR)) - lo->lo_flags ^= LO_FLAGS_AUTOCLEAR; + lo->lo_flags = info->lo_flags; lo->lo_encrypt_key_size = info->lo_encrypt_key_size; lo->lo_init[0] = info->lo_init[0]; @@ -1338,6 +1336,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) int err; struct block_device *bdev; kuid_t uid = current_uid(); + int prev_lo_flags; bool partscan = false; bool size_changed = false; loff_t validated_size; @@ -1381,10 +1380,19 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) goto out_unfreeze; } + prev_lo_flags = lo->lo_flags; + err = loop_set_status_from_info(lo, info); if (err) goto out_unfreeze; + /* Mask out flags that can't be set using LOOP_SET_STATUS. */ + lo->lo_flags &= ~LOOP_SET_STATUS_SETTABLE_FLAGS; + /* For those flags, use the previous values instead */ + lo->lo_flags |= prev_lo_flags & ~LOOP_SET_STATUS_SETTABLE_FLAGS; + /* For flags that can't be cleared, use previous values too */ + lo->lo_flags |= prev_lo_flags & ~LOOP_SET_STATUS_CLEARABLE_FLAGS; + if (size_changed) loop_set_size(lo, validated_size); @@ -1396,9 +1404,8 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) out_unfreeze: blk_mq_unfreeze_queue(lo->lo_queue); - if (!err && (info->lo_flags & LO_FLAGS_PARTSCAN) && - !(lo->lo_flags & LO_FLAGS_PARTSCAN)) { - lo->lo_flags |= LO_FLAGS_PARTSCAN; + if (!err && (lo->lo_flags & LO_FLAGS_PARTSCAN) && + !(prev_lo_flags & LO_FLAGS_PARTSCAN)) { lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; bdev = lo->lo_device; partscan = true; diff --git a/include/uapi/linux/loop.h b/include/uapi/linux/loop.h index 080a8df134ef..6b32fee80ce0 100644 --- a/include/uapi/linux/loop.h +++ b/include/uapi/linux/loop.h @@ -25,6 +25,12 @@ enum { LO_FLAGS_DIRECT_IO = 16, }; +/* LO_FLAGS that can be set using LOOP_SET_STATUS(64) */ +#define LOOP_SET_STATUS_SETTABLE_FLAGS (LO_FLAGS_AUTOCLEAR | LO_FLAGS_PARTSCAN) + +/* LO_FLAGS that can be cleared using LOOP_SET_STATUS(64) */ +#define LOOP_SET_STATUS_CLEARABLE_FLAGS (LO_FLAGS_AUTOCLEAR) + #include /* for __kernel_old_dev_t */ #include /* for __u64 */ @@ -37,7 +43,7 @@ struct loop_info { int lo_offset; int lo_encrypt_type; int lo_encrypt_key_size; /* ioctl w/o */ - int lo_flags; /* ioctl r/o */ + int lo_flags; char lo_name[LO_NAME_SIZE]; unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */ unsigned long lo_init[2]; @@ -53,7 +59,7 @@ struct loop_info64 { __u32 lo_number; /* ioctl r/o */ __u32 lo_encrypt_type; __u32 lo_encrypt_key_size; /* ioctl w/o */ - __u32 lo_flags; /* ioctl r/o */ + __u32 lo_flags; __u8 lo_file_name[LO_NAME_SIZE]; __u8 lo_crypt_name[LO_NAME_SIZE]; __u8 lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */