From patchwork Thu Jan 20 11:09:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shinichiro Kawasaki X-Patchwork-Id: 12718523 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 5A5C1C433EF for ; Thu, 20 Jan 2022 11:09:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229957AbiATLJS (ORCPT ); Thu, 20 Jan 2022 06:09:18 -0500 Received: from esa1.hgst.iphmx.com ([68.232.141.245]:62498 "EHLO esa1.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229576AbiATLJS (ORCPT ); Thu, 20 Jan 2022 06:09:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1642676958; x=1674212958; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=bBpgC/RK4BEyzCIX7qN0JaUvn2bwvqyNWuoiScHjlBo=; b=NXBTgOYbNXbFKXGJKviQX11hlBpkjWxFpq5oAPQYdfL2SKDd1F8WTRdc ss0otYtwICKX+CYq+LMVjb0EkXS5SR8vOrKNftYpQp8ZhuO57G7PppLrQ 4/DJvtmiTysHQ54gV4lf3yM8jYYkUjjopzUdTpLN8TMgJvu/lSYrV+WJ5 qT1Mj6xH6xok0A4YF+4attDfAa2fxlYJx/VeOoY8Kq/v+Ark57maPsu73 ruhx1zbqpUx8AhZsY09Ozysa++Wop2ybj6Fp2SWaJMi0ODxt+9jiiGC0u tRIhLUJ3kFwU4gnHep2q8iKiH0S6PWpH1AdgXAqoFys164jymvVzFw53T Q==; X-IronPort-AV: E=Sophos;i="5.88,302,1635177600"; d="scan'208";a="302802716" Received: from uls-op-cesaip01.wdc.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 20 Jan 2022 19:09:17 +0800 IronPort-SDR: dUAgmxSZ39tqplfiZ2XWsQ0eXTHUTw/DhrExePqV0wjeuILenRB/CY1XnvX1qs4rwGq8FQ+wXN 1dbaaqQyQIzCIADTpcAWRyW3ZXUQYvR+67aDMwBZMxuxvktRlPLJbFjRPWJfSa/1Ol5BFuFQop fgFKpeejA+Sw6lS0nipQ1nDDcbFE7AmSZPv2PqCGMVKsYmMDe3b06hgZVdS925SyA4bnBVhqMk sTNqepCsx6w70HpHHHX6qhkUEE19HmWcpmMP2USEuF1WdlzlP0eBgD41/hhpzvX/+yM4iAiqMK Z8+QUtu6oOguQ8cjH0nWTrt6 Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jan 2022 02:42:46 -0800 IronPort-SDR: WJGGXyoFxnCP1GwWQwFewxBU4CoM+eByfqSQ7qxoIwjoxcYAnWS8obRRQ+Sh6VdrQnCaWTPjuo esNF4OevrHBKtLtI0s1kufru86OJzZmgaMX8QA+j/V2wuOCquwfLqjqZ+4DG6d+j5BELtmTWeU BKUclduIbSA6uAgQTuYiDZFGonsKzSqnBT3eUV0MorEC4SgSzkuVs5MvCWQLGlRGU7YLpvE9PH 1EscYX69KutRBgFbdPXDcUW8z9iDChOVD9k5E6Xgeib5ZomFrcqgboos5/e6aAZar9M+hRLPqU e2U= WDCIronportException: Internal Received: from shindev.dhcp.fujisawa.hgst.com (HELO shindev.fujisawa.hgst.com) ([10.149.52.173]) by uls-op-cesaip02.wdc.com with ESMTP; 20 Jan 2022 03:09:16 -0800 From: Shin'ichiro Kawasaki To: linux-btrfs@vger.kernel.org, David Sterba Cc: Naohiro Aota , Johannes Thumshirn , Damien Le Moal , Shin'ichiro Kawasaki Subject: [PATCH v3] btrfs: fix deadlock between quota disable and qgroup rescan worker Date: Thu, 20 Jan 2022 20:09:16 +0900 Message-Id: <20220120110916.72810-1-shinichiro.kawasaki@wdc.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Quota disable ioctl starts a transaction before waiting for the qgroup rescan worker completes. However, this wait can be infinite and results in deadlock because of circular dependency among the quota disable ioctl, the qgroup rescan worker and the other task with transaction such as block group relocation task. The deadlock happens with the steps following: 1) Task A calls ioctl to disable quota. It starts a transaction and waits for qgroup rescan worker completes. 2) Task B such as block group relocation task starts a transaction and joins to the transaction that task A started. Then task B commits to the transaction. In this commit, task B waits for a commit by task A. 3) Task C as the qgroup rescan worker starts its job and starts a transaction. In this transaction start, task C waits for completion of the transaction that task A started and task B committed. This deadlock was found with fstests test case btrfs/115 and a zoned null_blk device. The test case enables and disables quota, and the block group reclaim was triggered during the quota disable by chance. The deadlock was also observed by running quota enable and disable in parallel with 'btrfs balance' command on regular null_blk devices. An example report of the deadlock: [ 372.469894] INFO: task kworker/u16:6:103 blocked for more than 122 seconds. [ 372.479944] Not tainted 5.16.0-rc8 #7 [ 372.485067] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 372.493898] task:kworker/u16:6 state:D stack: 0 pid: 103 ppid: 2 flags:0x00004000 [ 372.503285] Workqueue: btrfs-qgroup-rescan btrfs_work_helper [btrfs] [ 372.510782] Call Trace: [ 372.514092] [ 372.521684] __schedule+0xb56/0x4850 [ 372.530104] ? io_schedule_timeout+0x190/0x190 [ 372.538842] ? lockdep_hardirqs_on+0x7e/0x100 [ 372.547092] ? _raw_spin_unlock_irqrestore+0x3e/0x60 [ 372.555591] schedule+0xe0/0x270 [ 372.561894] btrfs_commit_transaction+0x18bb/0x2610 [btrfs] [ 372.570506] ? btrfs_apply_pending_changes+0x50/0x50 [btrfs] [ 372.578875] ? free_unref_page+0x3f2/0x650 [ 372.585484] ? finish_wait+0x270/0x270 [ 372.591594] ? release_extent_buffer+0x224/0x420 [btrfs] [ 372.599264] btrfs_qgroup_rescan_worker+0xc13/0x10c0 [btrfs] [ 372.607157] ? lock_release+0x3a9/0x6d0 [ 372.613054] ? btrfs_qgroup_account_extent+0xda0/0xda0 [btrfs] [ 372.620960] ? do_raw_spin_lock+0x11e/0x250 [ 372.627137] ? rwlock_bug.part.0+0x90/0x90 [ 372.633215] ? lock_is_held_type+0xe4/0x140 [ 372.639404] btrfs_work_helper+0x1ae/0xa90 [btrfs] [ 372.646268] process_one_work+0x7e9/0x1320 [ 372.652321] ? lock_release+0x6d0/0x6d0 [ 372.658081] ? pwq_dec_nr_in_flight+0x230/0x230 [ 372.664513] ? rwlock_bug.part.0+0x90/0x90 [ 372.670529] worker_thread+0x59e/0xf90 [ 372.676172] ? process_one_work+0x1320/0x1320 [ 372.682440] kthread+0x3b9/0x490 [ 372.687550] ? _raw_spin_unlock_irq+0x24/0x50 [ 372.693811] ? set_kthread_struct+0x100/0x100 [ 372.700052] ret_from_fork+0x22/0x30 [ 372.705517] [ 372.709747] INFO: task btrfs-transacti:2347 blocked for more than 123 seconds. [ 372.729827] Not tainted 5.16.0-rc8 #7 [ 372.745907] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 372.767106] task:btrfs-transacti state:D stack: 0 pid: 2347 ppid: 2 flags:0x00004000 [ 372.787776] Call Trace: [ 372.801652] [ 372.812961] __schedule+0xb56/0x4850 [ 372.830011] ? io_schedule_timeout+0x190/0x190 [ 372.852547] ? lockdep_hardirqs_on+0x7e/0x100 [ 372.871761] ? _raw_spin_unlock_irqrestore+0x3e/0x60 [ 372.886792] schedule+0xe0/0x270 [ 372.901685] wait_current_trans+0x22c/0x310 [btrfs] [ 372.919743] ? btrfs_put_transaction+0x3d0/0x3d0 [btrfs] [ 372.938923] ? finish_wait+0x270/0x270 [ 372.959085] ? join_transaction+0xc75/0xe30 [btrfs] [ 372.977706] start_transaction+0x938/0x10a0 [btrfs] [ 372.997168] transaction_kthread+0x19d/0x3c0 [btrfs] [ 373.013021] ? btrfs_cleanup_transaction.isra.0+0xfc0/0xfc0 [btrfs] [ 373.031678] kthread+0x3b9/0x490 [ 373.047420] ? _raw_spin_unlock_irq+0x24/0x50 [ 373.064645] ? set_kthread_struct+0x100/0x100 [ 373.078571] ret_from_fork+0x22/0x30 [ 373.091197] [ 373.105611] INFO: task btrfs:3145 blocked for more than 123 seconds. [ 373.114147] Not tainted 5.16.0-rc8 #7 [ 373.120401] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 373.130393] task:btrfs state:D stack: 0 pid: 3145 ppid: 3141 flags:0x00004000 [ 373.140998] Call Trace: [ 373.145501] [ 373.149654] __schedule+0xb56/0x4850 [ 373.155306] ? io_schedule_timeout+0x190/0x190 [ 373.161965] ? lockdep_hardirqs_on+0x7e/0x100 [ 373.168469] ? _raw_spin_unlock_irqrestore+0x3e/0x60 [ 373.175468] schedule+0xe0/0x270 [ 373.180814] wait_for_commit+0x104/0x150 [btrfs] [ 373.187643] ? test_and_set_bit+0x20/0x20 [btrfs] [ 373.194772] ? kmem_cache_free+0x124/0x550 [ 373.201191] ? btrfs_put_transaction+0x69/0x3d0 [btrfs] [ 373.208738] ? finish_wait+0x270/0x270 [ 373.214704] ? __btrfs_end_transaction+0x347/0x7b0 [btrfs] [ 373.222342] btrfs_commit_transaction+0x44d/0x2610 [btrfs] [ 373.230233] ? join_transaction+0x255/0xe30 [btrfs] [ 373.237334] ? btrfs_record_root_in_trans+0x4d/0x170 [btrfs] [ 373.245251] ? btrfs_apply_pending_changes+0x50/0x50 [btrfs] [ 373.253296] relocate_block_group+0x105/0xc20 [btrfs] [ 373.260533] ? mutex_lock_io_nested+0x1270/0x1270 [ 373.267516] ? btrfs_wait_nocow_writers+0x85/0x180 [btrfs] [ 373.275155] ? merge_reloc_roots+0x710/0x710 [btrfs] [ 373.283602] ? btrfs_wait_ordered_extents+0xd30/0xd30 [btrfs] [ 373.291934] ? kmem_cache_free+0x124/0x550 [ 373.298180] btrfs_relocate_block_group+0x35c/0x930 [btrfs] [ 373.306047] btrfs_relocate_chunk+0x85/0x210 [btrfs] [ 373.313229] btrfs_balance+0x12f4/0x2d20 [btrfs] [ 373.320227] ? lock_release+0x3a9/0x6d0 [ 373.326206] ? btrfs_relocate_chunk+0x210/0x210 [btrfs] [ 373.333591] ? lock_is_held_type+0xe4/0x140 [ 373.340031] ? rcu_read_lock_sched_held+0x3f/0x70 [ 373.346910] btrfs_ioctl_balance+0x548/0x700 [btrfs] [ 373.354207] btrfs_ioctl+0x7f2/0x71b0 [btrfs] [ 373.360774] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 373.367957] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 373.375327] ? btrfs_ioctl_get_supported_features+0x20/0x20 [btrfs] [ 373.383841] ? find_held_lock+0x2c/0x110 [ 373.389993] ? lock_release+0x3a9/0x6d0 [ 373.395828] ? mntput_no_expire+0xf7/0xad0 [ 373.402083] ? lock_is_held_type+0xe4/0x140 [ 373.408249] ? vfs_fileattr_set+0x9f0/0x9f0 [ 373.414486] ? selinux_file_ioctl+0x349/0x4e0 [ 373.420938] ? trace_raw_output_lock+0xb4/0xe0 [ 373.427442] ? selinux_inode_getsecctx+0x80/0x80 [ 373.434224] ? lockdep_hardirqs_on+0x7e/0x100 [ 373.440660] ? force_qs_rnp+0x2a0/0x6b0 [ 373.446534] ? lock_is_held_type+0x9b/0x140 [ 373.452763] ? __blkcg_punt_bio_submit+0x1b0/0x1b0 [ 373.459732] ? security_file_ioctl+0x50/0x90 [ 373.466089] __x64_sys_ioctl+0x127/0x190 [ 373.472022] do_syscall_64+0x3b/0x90 [ 373.477513] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 373.484823] RIP: 0033:0x7f8f4af7e2bb [ 373.490493] RSP: 002b:00007ffcbf936178 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 373.500197] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f8f4af7e2bb [ 373.509451] RDX: 00007ffcbf936220 RSI: 00000000c4009420 RDI: 0000000000000003 [ 373.518659] RBP: 00007ffcbf93774a R08: 0000000000000013 R09: 00007f8f4b02d4e0 [ 373.527872] R10: 00007f8f4ae87740 R11: 0000000000000246 R12: 0000000000000001 [ 373.537222] R13: 00007ffcbf936220 R14: 0000000000000000 R15: 0000000000000002 [ 373.546506] [ 373.550878] INFO: task btrfs:3146 blocked for more than 123 seconds. [ 373.559383] Not tainted 5.16.0-rc8 #7 [ 373.565748] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 373.575748] task:btrfs state:D stack: 0 pid: 3146 ppid: 2168 flags:0x00000000 [ 373.586314] Call Trace: [ 373.590846] [ 373.595121] __schedule+0xb56/0x4850 [ 373.600901] ? __lock_acquire+0x23db/0x5030 [ 373.607176] ? io_schedule_timeout+0x190/0x190 [ 373.613954] schedule+0xe0/0x270 [ 373.619157] schedule_timeout+0x168/0x220 [ 373.625170] ? usleep_range_state+0x150/0x150 [ 373.631653] ? mark_held_locks+0x9e/0xe0 [ 373.637767] ? do_raw_spin_lock+0x11e/0x250 [ 373.643993] ? lockdep_hardirqs_on_prepare+0x17b/0x410 [ 373.651267] ? _raw_spin_unlock_irq+0x24/0x50 [ 373.657677] ? lockdep_hardirqs_on+0x7e/0x100 [ 373.664103] wait_for_completion+0x163/0x250 [ 373.670437] ? bit_wait_timeout+0x160/0x160 [ 373.676585] btrfs_quota_disable+0x176/0x9a0 [btrfs] [ 373.683979] ? btrfs_quota_enable+0x12f0/0x12f0 [btrfs] [ 373.691340] ? down_write+0xd0/0x130 [ 373.696880] ? down_write_killable+0x150/0x150 [ 373.703352] btrfs_ioctl+0x3945/0x71b0 [btrfs] [ 373.710061] ? find_held_lock+0x2c/0x110 [ 373.716192] ? lock_release+0x3a9/0x6d0 [ 373.722047] ? __handle_mm_fault+0x23cd/0x3050 [ 373.728486] ? btrfs_ioctl_get_supported_features+0x20/0x20 [btrfs] [ 373.737032] ? set_pte+0x6a/0x90 [ 373.742271] ? do_raw_spin_unlock+0x55/0x1f0 [ 373.748506] ? lock_is_held_type+0xe4/0x140 [ 373.754792] ? vfs_fileattr_set+0x9f0/0x9f0 [ 373.761083] ? selinux_file_ioctl+0x349/0x4e0 [ 373.767521] ? selinux_inode_getsecctx+0x80/0x80 [ 373.774247] ? __up_read+0x182/0x6e0 [ 373.780026] ? count_memcg_events.constprop.0+0x46/0x60 [ 373.787281] ? up_write+0x460/0x460 [ 373.792932] ? security_file_ioctl+0x50/0x90 [ 373.799232] __x64_sys_ioctl+0x127/0x190 [ 373.805237] do_syscall_64+0x3b/0x90 [ 373.810947] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 373.818102] RIP: 0033:0x7f1383ea02bb [ 373.823847] RSP: 002b:00007fffeb4d71f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 373.833641] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1383ea02bb [ 373.842961] RDX: 00007fffeb4d7210 RSI: 00000000c0109428 RDI: 0000000000000003 [ 373.852179] RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000078 [ 373.861408] R10: 00007f1383daec78 R11: 0000000000000202 R12: 00007fffeb4d874a [ 373.870647] R13: 0000000000493099 R14: 0000000000000001 R15: 0000000000000000 [ 373.879838] [ 373.884018] Showing all locks held in the system: [ 373.894250] 3 locks held by kworker/4:1/58: [ 373.900356] 1 lock held by khungtaskd/63: [ 373.906333] #0: ffffffff8945ff60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 [ 373.917307] 3 locks held by kworker/u16:6/103: [ 373.923938] #0: ffff888127b4f138 ((wq_completion)btrfs-qgroup-rescan){+.+.}-{0:0}, at: process_one_work+0x712/0x1320 [ 373.936555] #1: ffff88810b817dd8 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work+0x73f/0x1320 [ 373.951109] #2: ffff888102dd4650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_qgroup_rescan_worker+0x1f6/0x10c0 [btrfs] [ 373.964027] 2 locks held by less/1803: [ 373.969982] #0: ffff88813ed56098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 [ 373.981295] #1: ffffc90000b3b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x9e2/0x1060 [ 373.992969] 1 lock held by btrfs-transacti/2347: [ 373.999893] #0: ffff88813d4887a8 (&fs_info->transaction_kthread_mutex){+.+.}-{3:3}, at: transaction_kthread+0xe3/0x3c0 [btrfs] [ 374.015872] 3 locks held by btrfs/3145: [ 374.022298] #0: ffff888102dd4460 (sb_writers#18){.+.+}-{0:0}, at: btrfs_ioctl_balance+0xc3/0x700 [btrfs] [ 374.034456] #1: ffff88813d48a0a0 (&fs_info->reclaim_bgs_lock){+.+.}-{3:3}, at: btrfs_balance+0xfe5/0x2d20 [btrfs] [ 374.047646] #2: ffff88813d488838 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: btrfs_relocate_block_group+0x354/0x930 [btrfs] [ 374.063295] 4 locks held by btrfs/3146: [ 374.069647] #0: ffff888102dd4460 (sb_writers#18){.+.+}-{0:0}, at: btrfs_ioctl+0x38b1/0x71b0 [btrfs] [ 374.081601] #1: ffff88813d488bb8 (&fs_info->subvol_sem){+.+.}-{3:3}, at: btrfs_ioctl+0x38fd/0x71b0 [btrfs] [ 374.094283] #2: ffff888102dd4650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_quota_disable+0xc8/0x9a0 [btrfs] [ 374.106885] #3: ffff88813d489800 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_disable+0xd5/0x9a0 [btrfs] [ 374.126780] ============================================= To avoid the deadlock, wait for the qgroup rescan worker to complete before starting the transaction for the quota disable ioctl. Clear BTRFS_FS_QUOTA_ENABLE flag before the wait and the transaction to request the worker to complete. On transaction start failure, set the BTRFS_FS_QUOTA_ENABLE flag again. These BTRFS_FS_QUOTA_ENABLE flag changes can be done safely since the function btrfs_quota_disable is not called concurrently because of fs_info->subvol_sem. Also check the BTRFS_FS_QUOTA_ENABLE flag in qgroup_rescan_init to avoid another qgroup rescan worker to start after the previous qgroup worker completed. Suggested-by: Nikolay Borisov Signed-off-by: Shin'ichiro Kawasaki Reviewed-by: Filipe Manana --- Changes from v2: * Added lockdep assert for fs_info->subvol_sem * Removed bit test of BTRFS_FS_QUOTA_ENABLED * Reflected other comments on the list Changes from v1: * Used BTRFS_FS_QUOTA_ENABLE flag instead of the new flag fs/btrfs/qgroup.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 8928275823a1..3ff0f8735b10 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -1185,9 +1185,24 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info) struct btrfs_trans_handle *trans = NULL; int ret = 0; + /* + * We need to have subvol_sem write locked, to prevent races between + * concurrent tasks trying to disable quotas, because we will unlock + * and relock qgroup_ioctl_lock across BTRFS_FS_QUOTA_ENABLED changes. + */ + lockdep_assert_held_write(&fs_info->subvol_sem); + mutex_lock(&fs_info->qgroup_ioctl_lock); if (!fs_info->quota_root) goto out; + + /* + * Request qgroup rescan worker to complete and wait for it. This wait + * must be done before transaction start for quota disable since it may + * deadlock with transaction by the qgroup rescan worker. + */ + clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); + btrfs_qgroup_wait_for_completion(fs_info, false); mutex_unlock(&fs_info->qgroup_ioctl_lock); /* @@ -1205,14 +1220,13 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info) if (IS_ERR(trans)) { ret = PTR_ERR(trans); trans = NULL; + set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); goto out; } if (!fs_info->quota_root) goto out; - clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); - btrfs_qgroup_wait_for_completion(fs_info, false); spin_lock(&fs_info->qgroup_lock); quota_root = fs_info->quota_root; fs_info->quota_root = NULL; @@ -3383,6 +3397,9 @@ qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid, btrfs_warn(fs_info, "qgroup rescan init failed, qgroup is not enabled"); ret = -EINVAL; + } else if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) { + /* quota disable is in progress */ + ret = -EBUSY; } if (ret) {