From patchwork Fri Jun 28 16:18:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Snitzer X-Patchwork-Id: 13716404 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A1C67157E91; Fri, 28 Jun 2024 16:18:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719591538; cv=none; b=fAccDhU4eVTicEfOgG9Oxi85R17Jwyp+mFVImQ/4rJxTq6/zty4WzOWbDW+vkwEE8n+A6jGb6CcygwyLaGGCTSACIuWPB5dPiPxnZQGatpIg7kI0xD5zO0YVGyWx+tN7awJO3tEhWX8DUUeJdI+kjVkZCfI3mS2bvWIeAEBdL5c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719591538; c=relaxed/simple; bh=vhbHqn0waWFUdaNqCqmKkeJzJtjPhQtwtdAd8Y6Wwe0=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=mBxgmtuy1yTHoQW+84IhsvUojhXecOaP2ekdytr3SSYzttjfdTjn2gJPJkZoitjkJZmQ61VTxil0UD8kN5DFFFgObMC6A8tRpuUhMiGpjCxogsbif8gYzEWzAyX09A7kGqssdRnOy3LF/cf62Hhw8ZVbONfJfXPsJqVU6FuCLoY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FC9aAub2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FC9aAub2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2EC3C116B1; Fri, 28 Jun 2024 16:18:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719591538; bh=vhbHqn0waWFUdaNqCqmKkeJzJtjPhQtwtdAd8Y6Wwe0=; h=Date:From:To:Cc:Subject:From; b=FC9aAub2yVhFBPeNJyB2zdaJb0aGk1GmA6cd41+vXKxLnyp+h2uET/1orQ5glehkQ b+Ya5wPBLhHIOke5YW/qyNvT4CYmzWhhjRxSDZCC83CEiAK3bFGm2vtWrNPJMihVge FmVdTlfndZVvZNOFYic+17AEGuYWjY1/BBxnFNzsmylcwtNd/WfiQWfLinFTbASTK3 yFus9OwmmLuhVjULnkAAgeQQcTLSowYWeMT4I2U4lkOz2m0vA7prvgEUitouiFtaxQ o66ep4kP60oNCdW7vqvrfEAGjjvAk2jOhzqB+7yxK9813xFWiJF+BInQJ37lhBkvLR S1UVHSLSn/LyA== Date: Fri, 28 Jun 2024 12:18:56 -0400 From: Mike Snitzer To: linux-xfs@vger.kernel.org Cc: linux-nfs@vger.kernel.org Subject: [RFC PATCH] xfs: enable WQ_MEM_RECLAIM on m_sync_workqueue Message-ID: Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline I'm developing an NFS feature called "localio" that bypasses the network, if both the client and server are on the same host, see: https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-6.11 Because NFS's nfsiod_workqueue enables WQ_MEM_RECLAIM, writeback will call into NFS and if localio is enabled the NFS client will call directly into xfs_file_write_iter, this causes the following backtrace: 00573 workqueue: WQ_MEM_RECLAIM writeback:wb_workfn is flushing !WQ_MEM_RECLAIM xfs-sync/vdc:xfs_flush_inodes_worker 00573 WARNING: CPU: 6 PID: 8525 at kernel/workqueue.c:3706 check_flush_dependency+0x2a4/0x328 00573 Modules linked in: 00573 CPU: 6 PID: 8525 Comm: kworker/u71:5 Not tainted 6.10.0-rc3-ktest-00032-g2b0a133403ab #18502 00573 Hardware name: linux,dummy-virt (DT) 00573 Workqueue: writeback wb_workfn (flush-0:33) 00573 pstate: 400010c5 (nZcv daIF -PAN -UAO -TCO -DIT +SSBS BTYPE=--) 0573 pc : check_flush_dependency+0x2a4/0x328 00573 lr : check_flush_dependency+0x2a4/0x328 00573 sp : ffff0000c5f06bb0 00573 x29: ffff0000c5f06bb0 x28: ffff0000c998a908 x27: 1fffe00019331521 00573 x26: ffff0000d0620900 x25: ffff0000c5f06ca0 x24: ffff8000828848c0 00573 x23: 1fffe00018be0d8e x22: ffff0000c1210000 x21: ffff0000c75fde00 00573 x20: ffff800080bfd258 x19: ffff0000cad63400 x18: ffff0000cd3a4810 00573 x17: 0000000000000000 x16: 0000000000000000 x15: ffff800080508d98 00573 x14: 0000000000000000 x13: 204d49414c434552 x12: 1fffe0001b6eeab2 00573 x11: ffff60001b6eeab2 x10: dfff800000000000 x9 : ffff60001b6eeab3 00573 x8 : 0000000000000001 x7 : 00009fffe491154e x6 : ffff0000db775593 00573 x5 : ffff0000db775590 x4 : ffff0000db775590 x3 : 0000000000000000 00573 x2 : 0000000000000027 x1 : ffff600018be0d62 x0 : dfff800000000000 00573 Call trace: 00573 check_flush_dependency+0x2a4/0x328 00573 __flush_work+0x184/0x5c8 00573 flush_work+0x18/0x28 00573 xfs_flush_inodes+0x68/0x88 00573 xfs_file_buffered_write+0x128/0x6f0 00573 xfs_file_write_iter+0x358/0x448 00573 nfs_local_doio+0x854/0x1568 00573 nfs_initiate_pgio+0x214/0x418 00573 nfs_generic_pg_pgios+0x304/0x480 00573 nfs_pageio_doio+0xe8/0x240 00573 nfs_pageio_complete+0x160/0x480 00573 nfs_writepages+0x300/0x4f0 00573 do_writepages+0x12c/0x4a0 00573 __writeback_single_inode+0xd4/0xa68 00573 writeback_sb_inodes+0x470/0xcb0 00573 __writeback_inodes_wb+0xb0/0x1d0 00573 wb_writeback+0x594/0x808 00573 wb_workfn+0x5e8/0x9e0 00573 process_scheduled_works+0x53c/0xd90 00573 worker_thread+0x370/0x8c8 00573 kthread+0x258/0x2e8 00573 ret_from_fork+0x10/0x20 Fix this by enabling WQ_MEM_RECLAIM on XFS's m_sync_workqueue. It could be this change is a non-starter due to WQ_MEM_RECLAIM no longer allowing m_sync_workqueue to be "sync"? All comments and suggestions welcome! Signed-off-by: Mike Snitzer diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 27e9f749c4c7..dbe6af00708b 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -574,7 +574,8 @@ xfs_init_mount_workqueues( goto out_destroy_blockgc; mp->m_sync_workqueue = alloc_workqueue("xfs-sync/%s", - XFS_WQFLAGS(WQ_FREEZABLE), 0, mp->m_super->s_id); + XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM), + 0, mp->m_super->s_id); if (!mp->m_sync_workqueue) goto out_destroy_inodegc;