From nobody Mon Feb 9 17:56:39 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61295C001B1 for ; Sat, 24 Jun 2023 23:10:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229945AbjFXXKO (ORCPT ); Sat, 24 Jun 2023 19:10:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229890AbjFXXKG (ORCPT ); Sat, 24 Jun 2023 19:10:06 -0400 Received: from wout1-smtp.messagingengine.com (wout1-smtp.messagingengine.com [64.147.123.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D1E41710 for ; Sat, 24 Jun 2023 16:10:05 -0700 (PDT) Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id 470663200065; Sat, 24 Jun 2023 19:10:04 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute3.internal (MEProxy); Sat, 24 Jun 2023 19:10:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= invisiblethingslab.com; h=cc:cc:content-transfer-encoding :content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to; s=fm2; t=1687648203; x=1687734603; bh=SeRemaMatw hMpngrZojgIC28QGOEX9vg96PFGAP8u/c=; b=mjxJHnYjCbSWGxJE4wLcnHFiqq KEktZaLlSYJWLgxLYbYAQH/G8Pj9WOpq2nsbbF8l40byU21jAUHwFTY5Ur1IBWRa Han4dBFZL5QRJtdXBxsm9fp6GOp83/IGFEL886SprPpbg6/pbE1UVSo+FZ+GJ6AI Uj1Qn3vsA3/T1NeWYvvp4lPIpvV+RcAXOZ/jQMtwQ8hvau6rbxGu8q8fwNKeKPOR WOUvweCK0lhAIr6QFO95OrBU9aFy5DrqsKYgEXNQ04SlBE3TyZCnaQlNQeIF7TAi Z7IK3/XqJbwt6HmybgqFpOA8sfOem+RUBBRrOS2NO7kU9VTVXPcdBIogqWSg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:feedback-id:feedback-id:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1687648203; x= 1687734603; bh=SeRemaMatwhMpngrZojgIC28QGOEX9vg96PFGAP8u/c=; b=H u4Uev6STVslzWqpTp2zDdXSbL9G0934GY3AOTJfoWTkIyHSfdcb24uopR9wvO9uJ Pki8wS0/JYlHgYd0fPWynxtj77X/hCELfeu9vZaXb3UwJXxnI1odq1FROVU2N8H8 OhxCHuEfg8hWxQHUeMlv1zcdDO93SfwYrEsTDAQwRAm3i1QwbmWScpJIebHmBmIk 0jfhsNF8fH/mY7+Jtjot4+Yyv+8WbMXgK7/lheGc9wc0i+maJoLwzKi+jU8ZDzX2 I3ELu4M6TNZZrjXK9SYLiWbQvSK0XIoirY9qIJyRx8TOwMrl/90FacQnJ3iP/YQE GfkmOXdstJIkI52QBdeLw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrgeegkedgudekucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhephffvvefufffkofgjfhgggfestdekredtredttdenucfhrhhomhepffgvmhhi ucforghrihgvucfqsggvnhhouhhruceouggvmhhisehinhhvihhsihgslhgvthhhihhngh hslhgrsgdrtghomheqnecuggftrfgrthhtvghrnhepjeffjefggfeugeduvedvjeekgfeh gffhhfffjeetkeelueefffetfffhtdduheetnecuvehluhhsthgvrhfuihiivgeptdenuc frrghrrghmpehmrghilhhfrhhomhepuggvmhhisehinhhvihhsihgslhgvthhhihhnghhs lhgrsgdrtghomh X-ME-Proxy: Feedback-ID: iac594737:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Sat, 24 Jun 2023 19:10:03 -0400 (EDT) From: Demi Marie Obenour To: Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com Cc: Demi Marie Obenour , linux-kernel@vger.kernel.org Subject: [PATCH v2 3/4] dm ioctl: Allow userspace to suppress uevent generation Date: Sat, 24 Jun 2023 19:09:46 -0400 Message-ID: <20230624230950.2272-4-demi@invisiblethingslab.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230624230950.2272-1-demi@invisiblethingslab.com> References: <20230624230950.2272-1-demi@invisiblethingslab.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Userspace can use this to avoid spamming udev with events that udev should ignore. Signed-off-by: Demi Marie Obenour --- drivers/md/dm-core.h | 2 + drivers/md/dm-ioctl.c | 71 ++++++++++++++++++----------------- drivers/md/dm.c | 5 ++- include/linux/device-mapper.h | 2 +- include/uapi/linux/dm-ioctl.h | 14 +++++-- 5 files changed, 54 insertions(+), 40 deletions(-) diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h index 0d93661f88d306e0d0aa3a1ac085880a8b63d9d6..5a4acdbf119f9b3f9a1c60de36d= 23f0658449701 100644 --- a/drivers/md/dm-core.h +++ b/drivers/md/dm-core.h @@ -115,6 +115,8 @@ struct mapped_device { =20 /* for blk-mq request-based DM support */ bool init_tio_pdu:1; + /* If set, do not emit any uevents. */ + bool disable_uevents:1; struct blk_mq_tag_set *tag_set; =20 struct dm_stats stats; diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 7abaeec33f1884d4588e8563fb02e9ea1a6782c8..7eab9a8c77ff3286346a1c44581= d3b6370a731eb 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -821,6 +821,11 @@ static struct dm_table *dm_get_live_or_inactive_table(= struct mapped_device *md, dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx); } =20 +static inline bool sloppy_checks(const struct dm_ioctl *param) +{ + return param->version[0] < DM_VERSION_MAJOR_STRICT; +} + /* * Fills in a dm_ioctl structure, ready for sending back to * userland. @@ -879,7 +884,7 @@ static void __dev_status(struct mapped_device *md, stru= ct dm_ioctl *param) dm_put_live_table(md, srcu_idx); } =20 - if (param->version[0] >=3D DM_VERSION_MAJOR_STRICT) + if (!sloppy_checks(param)) dm_set_diskseq(param, disk->diskseq); } =20 @@ -895,7 +900,7 @@ static int dev_create(struct file *filp, struct dm_ioct= l *param, size_t param_si if (param->flags & DM_PERSISTENT_DEV_FLAG) m =3D MINOR(huge_decode_dev(param->dev)); =20 - r =3D dm_create(m, &md); + r =3D dm_create(m, &md, param->flags & DM_DISABLE_UEVENTS_FLAG); if (r) return r; =20 @@ -1463,11 +1468,6 @@ static int next_target(struct dm_target_spec *last, = uint32_t next, const char *e return 0; } =20 -static inline bool sloppy_checks(const struct dm_ioctl *param) -{ - return param->version[0] < DM_VERSION_MAJOR_STRICT; -} - static bool no_non_nul_after_nul(const char *untrusted_str, size_t size, unsigned int cmd, const char *msg) { @@ -1939,64 +1939,67 @@ static int target_message(struct file *filp, struct= dm_ioctl *param, size_t para * Implementation of open/close/ioctl on the special char device. *--------------------------------------------------------------- */ -static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags, uint32_t = *supported_flags) +static ioctl_fn lookup_ioctl(unsigned int cmd, bool strict, int *ioctl_fla= gs, + uint32_t *supported_flags) { static const struct { int cmd; int flags; ioctl_fn fn; uint32_t supported_flags; + uint32_t strict_flags; } _ioctls[] =3D { /* Macro to make the structure initializers somewhat readable */ -#define I(cmd, flags, fn, supported_flags) ((typeof(_ioctls[0])) { \ +#define I(cmd, flags, fn, supported_flags, strict_flags) ((typeof(_ioctls[= 0])) { \ (cmd), \ (flags), \ (fn), \ /* * Supported flags in sloppy mode must not include anything in DM_STRICT_= ONLY_FLAGS. - * Use BUILD_BUG_ON_ZERO to check for that. Currently there are no stric= t-only flags - * defined. + * Use BUILD_BUG_ON_ZERO to check for that. */ \ (supported_flags) | BUILD_BUG_ON_ZERO((supported_flags) & DM_STRICT_ONLY_= FLAGS), \ + (strict_flags) | (supported_flags) | \ + BUILD_BUG_ON_ZERO((supported_flags) & (strict_flags)), \ }) - I(DM_VERSION_CMD, 0, NULL, 0), /* version is dealt with elsewhere */ + I(DM_VERSION_CMD, 0, NULL, 0, 0), /* version is dealt with elsewhere */ I(DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EV= ENT, - remove_all, DM_DEFERRED_REMOVE), - I(DM_LIST_DEVICES_CMD, 0, list_devices, DM_UUID_FLAG), + remove_all, DM_DEFERRED_REMOVE, 0), + I(DM_LIST_DEVICES_CMD, 0, list_devices, DM_UUID_FLAG, 0), I(DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EV= ENT, - dev_create, DM_PERSISTENT_DEV_FLAG), + dev_create, DM_PERSISTENT_DEV_FLAG, DM_DISABLE_UEVENTS_FLAG), I(DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EV= ENT, - dev_remove, DM_DEFERRED_REMOVE), + dev_remove, DM_DEFERRED_REMOVE, 0), I(DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename, - DM_QUERY_INACTIVE_TABLE_FLAG | DM_UUID_FLAG), + DM_QUERY_INACTIVE_TABLE_FLAG | DM_UUID_FLAG, 0), I(DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend, - DM_QUERY_INACTIVE_TABLE_FLAG | DM_SUSPEND_FLAG | DM_SKIP_LOCKFS_FLAG | - DM_NOFLUSH_FLAG), + DM_QUERY_INACTIVE_TABLE_FLAG | DM_SUSPEND_FLAG | + DM_SKIP_LOCKFS_FLAG | DM_NOFLUSH_FLAG, 0), I(DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status, - DM_QUERY_INACTIVE_TABLE_FLAG), + DM_QUERY_INACTIVE_TABLE_FLAG, 0), I(DM_DEV_WAIT_CMD, IOCTL_FLAGS_TAKES_EVENT_NR, dev_wait, - DM_QUERY_INACTIVE_TABLE_FLAG | DM_STATUS_TABLE_FLAG | DM_NOFLUSH_FLAG), - I(DM_TABLE_LOAD_CMD, 0, table_load, DM_QUERY_INACTIVE_TABLE_FLAG | - DM_READONLY_FLAG), + DM_QUERY_INACTIVE_TABLE_FLAG | DM_STATUS_TABLE_FLAG | DM_NOFLUSH_FLAG,= 0), + I(DM_TABLE_LOAD_CMD, 0, table_load, + DM_QUERY_INACTIVE_TABLE_FLAG | DM_READONLY_FLAG, 0), I(DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear, - DM_QUERY_INACTIVE_TABLE_FLAG), - I(DM_TABLE_DEPS_CMD, 0, table_deps, DM_QUERY_INACTIVE_TABLE_FLAG), + DM_QUERY_INACTIVE_TABLE_FLAG, 0), + I(DM_TABLE_DEPS_CMD, 0, table_deps, DM_QUERY_INACTIVE_TABLE_FLAG, 0), I(DM_TABLE_STATUS_CMD, 0, table_status, - DM_QUERY_INACTIVE_TABLE_FLAG | DM_STATUS_TABLE_FLAG | DM_NOFLUSH_FLAG), + DM_QUERY_INACTIVE_TABLE_FLAG | DM_STATUS_TABLE_FLAG | DM_NOFLUSH_FLAG, = 0), =20 - I(DM_LIST_VERSIONS_CMD, 0, list_versions, 0), + I(DM_LIST_VERSIONS_CMD, 0, list_versions, 0, 0), =20 - I(DM_TARGET_MSG_CMD, 0, target_message, DM_QUERY_INACTIVE_TABLE_FLAG), - I(DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry, 0), - I(DM_DEV_ARM_POLL_CMD, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll, 0), - I(DM_GET_TARGET_VERSION_CMD, 0, get_target_version, 0), + I(DM_TARGET_MSG_CMD, 0, target_message, DM_QUERY_INACTIVE_TABLE_FLAG, 0), + I(DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry, 0, 0), + I(DM_DEV_ARM_POLL_CMD, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll, 0, 0), + I(DM_GET_TARGET_VERSION_CMD, 0, get_target_version, 0, 0), }; =20 if (unlikely(cmd >=3D ARRAY_SIZE(_ioctls))) return NULL; =20 cmd =3D array_index_nospec(cmd, ARRAY_SIZE(_ioctls)); - *supported_flags =3D _ioctls[cmd].supported_flags; + *supported_flags =3D strict ? _ioctls[cmd].strict_flags : _ioctls[cmd].su= pported_flags; *ioctl_flags =3D _ioctls[cmd].flags; return _ioctls[cmd].fn; } @@ -2260,7 +2263,7 @@ static int ctl_ioctl(struct file *file, uint command,= struct dm_ioctl __user *us if (cmd =3D=3D DM_VERSION_CMD) return 0; =20 - fn =3D lookup_ioctl(cmd, &ioctl_flags, &supported_flags); + fn =3D lookup_ioctl(cmd, !sloppy_checks(¶m_kernel), &ioctl_flags, &su= pported_flags); if (!fn) { DMERR("dm_ctl_ioctl: unknown command 0x%x", command); return -ENOTTY; @@ -2480,7 +2483,7 @@ int __init dm_early_create(struct dm_ioctl *dmi, m =3D MINOR(huge_decode_dev(dmi->dev)); =20 /* alloc dm device */ - r =3D dm_create(m, &md); + r =3D dm_create(m, &md, false); if (r) return r; =20 diff --git a/drivers/md/dm.c b/drivers/md/dm.c index ea1671c39ba131ab2e49b93289d1094cda5cfb25..b7817b4aea52033afeeea9f2b93= b9215de682e9c 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2281,13 +2281,14 @@ static struct dm_table *__unbind(struct mapped_devi= ce *md) /* * Constructor for a new device. */ -int dm_create(int minor, struct mapped_device **result) +int dm_create(int minor, struct mapped_device **result, bool disable_ueven= ts) { struct mapped_device *md; =20 md =3D alloc_dev(minor); if (!md) return -ENXIO; + md->disable_uevents =3D disable_uevents; =20 dm_ima_reset_data(md); =20 @@ -3005,6 +3006,8 @@ int dm_kobject_uevent(struct mapped_device *md, enum = kobject_action action, char udev_cookie[DM_COOKIE_LENGTH]; char *envp[3] =3D { NULL, NULL, NULL }; char **envpp =3D envp; + if (md->disable_uevents) + return 0; if (cookie) { snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=3D%u", DM_COOKIE_ENV_VAR_NAME, cookie); diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 69d0435c7ebb0d7b712e2b8bf32d9ba34c54e09e..2be940c2c6f42ed8e13b97ea8b0= 7d0895566f3e2 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -461,7 +461,7 @@ void dm_consume_args(struct dm_arg_set *as, unsigned in= t num_args); * DM_ANY_MINOR chooses the next available minor number. */ #define DM_ANY_MINOR (-1) -int dm_create(int minor, struct mapped_device **md); +int dm_create(int minor, struct mapped_device **md, bool disable_uevents); =20 /* * Reference counting for md. diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h index 1d33109aece2ff9854e752066baa96fdf7d85857..b338a4f9a299acda9430995d63f= bb490e70c8cd8 100644 --- a/include/uapi/linux/dm-ioctl.h +++ b/include/uapi/linux/dm-ioctl.h @@ -369,8 +369,16 @@ enum { #define DM_BUFFER_FULL_FLAG (1 << 8) /* Out */ =20 /* - * This flag is now ignored if DM_VERSION_MAJOR is used, and causes - * -EINVAL if DM_VERSION_MAJOR_STRICT is used. + * This flag is only recognized when DM_VERSION_MAJOR_STRICT is used. + * It tells the kernel to not generate any uevents for the newly-created + * device. Using it outside of DM_DEV_CREATE results in -EINVAL. When + * DM_VERSION_MAJOR is used this flag is ignored. + */ +#define DM_DISABLE_UEVENTS_FLAG (1 << 9) /* In */ + +/* + * This flag is now ignored if DM_VERSION_MAJOR is used. When + * DM_VERSION_MAJOR_STRICT is used it is an alias for DM_DISABLE_UEVENT_FL= AG. */ #define DM_SKIP_BDGET_FLAG (1 << 9) /* In */ =20 @@ -439,8 +447,6 @@ enum { =20 /* * If DM_VERSION_MAJOR is used, these flags are ignored by the kernel. - * If DM_VERSION_MAJOR_STRICT is used, these flags are reserved and - * must be zeroed. */ #define DM_STRICT_ONLY_FLAGS \ (DM_ACTIVE_PRESENT_FLAG | DM_INACTIVE_PRESENT_FLAG | \ --=20 Sincerely, Demi Marie Obenour (she/her/hers) Invisible Things Lab