Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751404AbdIJQHQ (ORCPT ); Sun, 10 Sep 2017 12:07:16 -0400 Received: from scorn.kernelslacker.org ([45.56.101.199]:52918 "EHLO scorn.kernelslacker.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750709AbdIJQHO (ORCPT ); Sun, 10 Sep 2017 12:07:14 -0400 Date: Sun, 10 Sep 2017 12:07:10 -0400 From: Dave Jones To: Al Viro Cc: Dave Chinner , "Darrick J. Wong" , Linux Kernel , linux-xfs@vger.kernel.org Subject: Re: iov_iter_pipe warning. Message-ID: <20170910160710.7myz4iel2mnvya3b@codemonkey.org.uk> Mail-Followup-To: Dave Jones , Al Viro , Dave Chinner , "Darrick J. Wong" , Linux Kernel , linux-xfs@vger.kernel.org References: <20170428165024.ofyl2atpjwohekqa@codemonkey.org.uk> <20170428172024.GL29622@ZenIV.linux.org.uk> <20170807201818.kykqzexce6ap6aik@codemonkey.org.uk> <20170828203130.y6dq5fqovev6wmrv@codemonkey.org.uk> <20170829042542.GO4757@magnolia> <20170906200337.b5wj3gpfebliindw@codemonkey.org.uk> <20170906234617.GW17782@dastard> <20170908010441.GZ5426@ZenIV.linux.org.uk> <20170910010756.hnmb233ch7pmnrlx@codemonkey.org.uk> <20170910025712.GC5426@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170910025712.GC5426@ZenIV.linux.org.uk> User-Agent: NeoMutt/20170609 (1.8.3) X-Spam-Note: SpamAssassin invocation failed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4081 Lines: 100 On Sun, Sep 10, 2017 at 03:57:21AM +0100, Al Viro wrote: > On Sat, Sep 09, 2017 at 09:07:56PM -0400, Dave Jones wrote: > > > With this in place, I'm still seeing -EBUSY from invalidate_inode_pages2_range > > which doesn't end well... > > Different issue, and I'm not sure why that WARN_ON() is there in the > first place. Note that in a similar situation generic_file_direct_write() > simply buggers off and lets the caller do buffered write... > > iov_iter_pipe() warning is a sign of ->read_iter() on pipe-backed iov_iter > putting into the pipe more than it claims to have done. (from a rerun after hitting that EBUSY warn; hence the taint) WARNING: CPU: 0 PID: 14154 at fs/iomap.c:1055 iomap_dio_rw+0x78e/0x840 CPU: 0 PID: 14154 Comm: trinity-c33 Tainted: G W 4.13.0-think+ #9 task: ffff8801027e3e40 task.stack: ffff8801632d8000 RIP: 0010:iomap_dio_rw+0x78e/0x840 RSP: 0018:ffff8801632df370 EFLAGS: 00010286 RAX: 00000000fffffff0 RBX: ffff880428666428 RCX: ffffffffffffffea RDX: ffffed002c65bdef RSI: 0000000000000000 RDI: ffffed002c65be5f RBP: ffff8801632df550 R08: ffff88046ae176c0 R09: 0000000000000000 R10: ffff8801632de960 R11: 0000000000000001 R12: ffff8801632df7f0 R13: ffffffffffffffea R14: 1ffff1002c65be7c R15: ffff8801632df988 FS: 00007f3da2100700(0000) GS:ffff88046ae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000002f6223001 CR4: 00000000001606f0 DR0: 00007f3da1f3d000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: ? iomap_seek_data+0xb0/0xb0 ? find_inode_fast+0xd0/0xd0 ? xfs_file_aio_write_checks+0x295/0x320 [xfs] ? __lock_is_held+0x51/0xc0 ? xfs_file_dio_aio_write+0x286/0x7e0 [xfs] ? rcu_read_lock_sched_held+0x90/0xa0 xfs_file_dio_aio_write+0x286/0x7e0 [xfs] ? xfs_file_aio_write_checks+0x320/0x320 [xfs] ? unwind_get_return_address+0x2f/0x50 ? __save_stack_trace+0x92/0x100 ? memcmp+0x45/0x70 ? depot_save_stack+0x12e/0x480 ? save_stack+0x89/0xb0 ? save_stack+0x32/0xb0 ? kasan_kmalloc+0xa0/0xd0 ? __kmalloc+0x157/0x360 ? iter_file_splice_write+0x154/0x760 ? direct_splice_actor+0x86/0xa0 ? splice_direct_to_actor+0x1c4/0x420 ? do_splice_direct+0x173/0x1e0 ? do_sendfile+0x3a2/0x6d0 ? SyS_sendfile64+0xa4/0x130 ? do_syscall_64+0x182/0x3e0 ? entry_SYSCALL64_slow_path+0x25/0x25 ? match_held_lock+0xa6/0x410 ? iter_file_splice_write+0x154/0x760 xfs_file_write_iter+0x227/0x280 [xfs] do_iter_readv_writev+0x267/0x330 ? vfs_dedupe_file_range+0x400/0x400 do_iter_write+0xd7/0x280 ? splice_from_pipe_next.part.9+0x28/0x160 iter_file_splice_write+0x4d5/0x760 ? page_cache_pipe_buf_steal+0x2b0/0x2b0 ? generic_file_splice_read+0x2e1/0x340 ? pipe_to_user+0x80/0x80 direct_splice_actor+0x86/0xa0 splice_direct_to_actor+0x1c4/0x420 ? generic_pipe_buf_nosteal+0x10/0x10 ? do_splice_to+0xc0/0xc0 do_splice_direct+0x173/0x1e0 ? splice_direct_to_actor+0x420/0x420 ? rcu_read_lock_sched_held+0x90/0xa0 ? rcu_sync_lockdep_assert+0x43/0x70 ? __sb_start_write+0x179/0x1e0 do_sendfile+0x3a2/0x6d0 ? do_compat_pwritev64+0xa0/0xa0 ? __lock_is_held+0x2e/0xc0 SyS_sendfile64+0xa4/0x130 ? SyS_sendfile+0x140/0x140 ? mark_held_locks+0x1c/0x90 ? do_syscall_64+0xae/0x3e0 ? SyS_sendfile+0x140/0x140 do_syscall_64+0x182/0x3e0 ? syscall_return_slowpath+0x250/0x250 ? rcu_read_lock_sched_held+0x90/0xa0 ? __context_tracking_exit.part.4+0x223/0x290 ? mark_held_locks+0x1c/0x90 ? return_from_SYSCALL_64+0x2d/0x7a ? trace_hardirqs_on_caller+0x17a/0x250 ? trace_hardirqs_on_thunk+0x1a/0x1c entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7f3da1a2b219 RSP: 002b:00007ffdd1642f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000028 RCX: 00007f3da1a2b219 RDX: 00007f3da1f3d000 RSI: 000000000000005f RDI: 0000000000000060 RBP: 00007ffdd1642fe0 R08: 30503123188dbe3f R09: ffffffffe7e7e7e7 R10: 000000000000f000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007f3da2012058 R14: 00007f3da2100698 R15: 00007f3da2012000