From mboxrd@z Thu Jan 1 00:00:00 1970 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 60A91C433F5 for ; Mon, 24 Jan 2022 15:02:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239895AbiAXPC2 (ORCPT ); Mon, 24 Jan 2022 10:02:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239164AbiAXPCV (ORCPT ); Mon, 24 Jan 2022 10:02:21 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A8603C061744 for ; Mon, 24 Jan 2022 07:02:19 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id o131-20020a25d789000000b00614957c60dfso20236713ybg.15 for ; Mon, 24 Jan 2022 07:02:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=P9O4S8d3oVVuE/vD4lm4oLLN+5OcE1ItgKs9PC2D6EQ=; b=RbOoDBHdS9Mk6OK3SJ9PPM+mCNh2UAhlNARXtgZVfAm7zlUQUtozE/n3XqLGmcfFGM CoWrEidql331DXpXkWFFAHflk7wghEreatdUUOkWnWToIoQJqUbXPsutn4a1VCLohRbm HrdbE9Bcr7mOchpdYl0YCr3Y1B0NOW+SL6a0WfyG8rkRIeEB3PyCCFVHYFw2W21DePfX 7oLxN64x6OejuSlIzDEEcVo3qI3QS+9qGgydEao6YFkYgqlDVieQd+dolWJlzu54+Hys 5dbPOyOmqyC4zgXYXkybvf31WpK94c+X5lCH+CXB01IpxGzQxlL7jH7u4hNkLG0c+qNH pLyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=P9O4S8d3oVVuE/vD4lm4oLLN+5OcE1ItgKs9PC2D6EQ=; b=2JsRQdi+OTAJgOhglIeRu5CQdkaz3hcmjoCKiBLxtE+djFbl5QgN3uBudLQZoh33Vk 0JcLkgAo/0Z/MPrO9+dob7+iTy+OJa0AXnhtPJ62sPU0ZMVLwFXKdyNQgYe+6ZJCtevS fwmFI2ObryPGE6TJuCqaAqkbTJR8z3lQmmzqwqeEBnXxOOxf10Q6YhnljQA+/0y0qKuS 0r/ozeN3L+Tum7oVAwQ1HrjP2RnVp2D55iXOtY2Z4qQjjjRj8UIifnGlhytZlxBRyZKz btHwPOA9Fy+vLys5aR4g6ptxWWrWyAEpL0q9ikELbXocgtxUTyildq8CQgxCPGPffSW8 L9Ug== X-Gm-Message-State: AOAM530LimS6OlENRoNH/P+Tw1GyRtn0qJCTiQ4D8ysV1qG2QPNvy6GE mB4W630BG9PPdWtnEtWrwLUoaCEVS7x/ X-Google-Smtp-Source: ABdhPJxEDxMzU3Yk4N5L5onA4XuAOtA/Fbwxz6Je+TTJqD3UwlmWmOg3jITYTUdrlKYe14tuDKOK/3SDtfDw X-Received: from bg.sfo.corp.google.com ([2620:15c:11a:202:9491:3e69:9a74:1f3]) (user=bgeffon job=sendgmr) by 2002:a25:bb0e:: with SMTP id z14mr26156550ybg.762.1643036538880; Mon, 24 Jan 2022 07:02:18 -0800 (PST) Date: Mon, 24 Jan 2022 07:02:09 -0800 Message-Id: <20220124150209.22202-1-bgeffon@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.34.1.703.g22d0c6ccf7-goog Subject: [PATCH] dm: introduce a no open flag for deferred remove From: Brian Geffon To: Alasdair Kergon , Mike Snitzer Cc: dm-devel@redhat.com, linux-kernel@vger.kernel.org, Brian Geffon Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When a device is being removed with deferred remove it's still possible to open and use the device. This change introduces a flag called DM_DEFERRED_REMOVE_NO_OPEN_FLAG which when used with DM_DEFERRED_REMOVE will cause any new opens to fail with -ENXIO. If this flag is used without DM_DEFERRED_REMOVE it will result in an -EINVAL. Signed-off-by: Brian Geffon --- drivers/md/dm-core.h | 1 + drivers/md/dm-ioctl.c | 39 +++++++++++++++++++++++++++-------- drivers/md/dm.c | 21 ++++++++++++++++--- drivers/md/dm.h | 9 +++++++- include/uapi/linux/dm-ioctl.h | 12 +++++++++-- 5 files changed, 67 insertions(+), 15 deletions(-) diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h index b855fef4f38a..b30e59deb4a8 100644 --- a/drivers/md/dm-core.h +++ b/drivers/md/dm-core.h @@ -139,6 +139,7 @@ struct mapped_device { #define DMF_SUSPENDED_INTERNALLY 7 #define DMF_POST_SUSPENDING 8 #define DMF_EMULATE_ZONE_APPEND 9 +#define DMF_DEFERRED_REMOVE_NO_OPEN 10 void disable_discard(struct mapped_device *md); void disable_write_same(struct mapped_device *md); diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 21fe8652b095..07bb679880de 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -60,7 +60,8 @@ struct vers_iter { static struct rb_root name_rb_tree = RB_ROOT; static struct rb_root uuid_rb_tree = RB_ROOT; -static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred); +static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, + bool deferred_no_open, bool only_deferred); /* * Guards access to both hash tables. @@ -74,7 +75,7 @@ static DEFINE_MUTEX(dm_hash_cells_mutex); static void dm_hash_exit(void) { - dm_hash_remove_all(false, false, false); + dm_hash_remove_all(false, false, false, false); } /*----------------------------------------------------------------- @@ -315,7 +316,8 @@ static struct dm_table *__hash_remove(struct hash_cell *hc) return table; } -static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred) +static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, + bool deferred_no_open, bool only_deferred) { int dev_skipped; struct rb_node *n; @@ -334,7 +336,8 @@ static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool dm_get(md); if (keep_open_devices && - dm_lock_for_deletion(md, mark_deferred, only_deferred)) { + dm_lock_for_deletion(md, mark_deferred, deferred_no_open, + only_deferred)) { dm_put(md); dev_skipped++; continue; @@ -496,7 +499,7 @@ static struct mapped_device *dm_hash_rename(struct dm_ioctl *param, void dm_deferred_remove(void) { - dm_hash_remove_all(true, false, true); + dm_hash_remove_all(true, false, false, true); } /*----------------------------------------------------------------- @@ -510,7 +513,13 @@ typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_ static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size) { - dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false); + if (param->flags & DM_DEFERRED_REMOVE_NO_OPEN_FLAG && + !(param->flags & DM_DEFERRED_REMOVE)) { + return -EINVAL; + } + + dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), + !!(param->flags & DM_DEFERRED_REMOVE_NO_OPEN_FLAG), false); param->data_size = 0; return 0; } @@ -811,9 +820,13 @@ static void __dev_status(struct mapped_device *md, struct dm_ioctl *param) if (dm_suspended_internally_md(md)) param->flags |= DM_INTERNAL_SUSPEND_FLAG; - if (dm_test_deferred_remove_flag(md)) + if (dm_test_deferred_remove_flag(md)) { param->flags |= DM_DEFERRED_REMOVE; + if (dm_test_deferred_remove_no_open_flag(md)) + param->flags |= DM_DEFERRED_REMOVE_NO_OPEN_FLAG; + } + param->dev = huge_encode_dev(disk_devt(disk)); /* @@ -960,10 +973,18 @@ static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_si md = hc->md; + if (param->flags & DM_DEFERRED_REMOVE_NO_OPEN_FLAG && + !(param->flags & DM_DEFERRED_REMOVE)) { + up_write(&_hash_lock); + dm_put(md); + return -EINVAL; + } + /* * Ensure the device is not open and nothing further can open it. */ - r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false); + r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), + !!(param->flags & DM_DEFERRED_REMOVE_NO_OPEN_FLAG), false); if (r) { if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) { up_write(&_hash_lock); @@ -984,7 +1005,7 @@ static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_si dm_table_destroy(t); } - param->flags &= ~DM_DEFERRED_REMOVE; + param->flags &= ~(DM_DEFERRED_REMOVE | DM_DEFERRED_REMOVE_NO_OPEN_FLAG); dm_ima_measure_on_device_remove(md, false); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index c0ae8087c602..90b74043e162 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -315,7 +315,10 @@ static int dm_blk_open(struct block_device *bdev, fmode_t mode) goto out; if (test_bit(DMF_FREEING, &md->flags) || + test_bit(DMF_DEFERRED_REMOVE_NO_OPEN, &md->flags) || dm_deleting_md(md)) { + BUG_ON(test_bit(DMF_DEFERRED_REMOVE_NO_OPEN, &md->flags) && + !test_bit(DMF_DEFERRED_REMOVE, &md->flags)); md = NULL; goto out; } @@ -355,7 +358,8 @@ int dm_open_count(struct mapped_device *md) /* * Guarantees nothing is using the device before it's deleted. */ -int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred) +int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, + bool deferred_no_open, bool only_deferred) { int r = 0; @@ -363,8 +367,12 @@ int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only if (dm_open_count(md)) { r = -EBUSY; - if (mark_deferred) + if (mark_deferred) { set_bit(DMF_DEFERRED_REMOVE, &md->flags); + + if (deferred_no_open) + set_bit(DMF_DEFERRED_REMOVE_NO_OPEN, &md->flags); + } } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags)) r = -EEXIST; else @@ -383,8 +391,10 @@ int dm_cancel_deferred_remove(struct mapped_device *md) if (test_bit(DMF_DELETING, &md->flags)) r = -EBUSY; - else + else { clear_bit(DMF_DEFERRED_REMOVE, &md->flags); + clear_bit(DMF_DEFERRED_REMOVE_NO_OPEN, &md->flags); + } spin_unlock(&_minor_lock); @@ -2718,6 +2728,11 @@ int dm_test_deferred_remove_flag(struct mapped_device *md) return test_bit(DMF_DEFERRED_REMOVE, &md->flags); } +int dm_test_deferred_remove_no_open_flag(struct mapped_device *md) +{ + return test_bit(DMF_DEFERRED_REMOVE_NO_OPEN, &md->flags); +} + int dm_suspended(struct dm_target *ti) { return dm_suspended_md(ti->table->md); diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 9013dc1a7b00..8d0d4344f882 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -158,6 +158,12 @@ void dm_internal_resume(struct mapped_device *md); */ int dm_test_deferred_remove_flag(struct mapped_device *md); +/* + * Test if the device is scheduled for deferred remove while + * disallowing opens. + */ +int dm_test_deferred_remove_no_open_flag(struct mapped_device *md); + /* * Try to remove devices marked for deferred removal. */ @@ -198,7 +204,8 @@ void dm_stripe_exit(void); void dm_destroy(struct mapped_device *md); void dm_destroy_immediate(struct mapped_device *md); int dm_open_count(struct mapped_device *md); -int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred); +int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, + bool deferred_no_open, bool only_deferred); int dm_cancel_deferred_remove(struct mapped_device *md); int dm_request_based(struct mapped_device *md); int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode, diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h index c12ce30b52df..c0fee607b827 100644 --- a/include/uapi/linux/dm-ioctl.h +++ b/include/uapi/linux/dm-ioctl.h @@ -286,9 +286,9 @@ enum { #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) #define DM_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 45 +#define DM_VERSION_MINOR 46 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2021-03-22)" +#define DM_VERSION_EXTRA "-ioctl (2022-01-21)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */ @@ -382,4 +382,12 @@ enum { */ #define DM_IMA_MEASUREMENT_FLAG (1 << 19) /* In */ +/* If set with DF_DEFERRED_REMOVE if an immediate remove is not + * possible because the device is still open any new additional + * opens will also be rejected. + * + * It is an error to specify this flag without DM_DEFERRED_REMOVE. + */ +#define DM_DEFERRED_REMOVE_NO_OPEN_FLAG (1 << 20) /* In/Out */ + #endif /* _LINUX_DM_IOCTL_H */ -- 2.35.0.rc0.227.g00780c9af4-goog