From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:42341 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932210AbdJJOgb (ORCPT ); Tue, 10 Oct 2017 10:36:31 -0400 Date: Tue, 10 Oct 2017 16:34:45 +0200 From: David Sterba To: Lukas Czerner Cc: linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz, jmoyer@redhat.com, david@fromorbit.com, bo.li.liu@oracle.com, clm@fb.com Subject: Re: [PATCH v7] fs: Fix page cache inconsistency when mixing buffered and AIO DIO Message-ID: <20171010143445.GO3521@twin.jikos.cz> Reply-To: dsterba@suse.cz References: <1502369997-15665-1-git-send-email-lczerner@redhat.com> <1502803734-27706-1-git-send-email-lczerner@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1502803734-27706-1-git-send-email-lczerner@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, Aug 15, 2017 at 03:28:54PM +0200, Lukas Czerner wrote: > + /* > + * Try again to invalidate clean pages which might have been cached by > + * non-direct readahead, or faulted in by get_user_pages() if the source > + * of the write was an mmap'ed region of the file we're writing. Either > + * one is a pretty crazy thing to do, so we don't support it 100%. If > + * this invalidation fails, tough, the write still worked... > + */ > + if (ret > 0 && dio->op == REQ_OP_WRITE && > + dio->inode->i_mapping->nrpages) { > + err = invalidate_inode_pages2_range(dio->inode->i_mapping, > + offset >> PAGE_SHIFT, > + (offset + ret - 1) >> PAGE_SHIFT); > + WARN_ON_ONCE(err); fstests/btrfs/062 reports this: [ 6235.547298] ------------[ cut here ]------------ [ 6235.552098] WARNING: CPU: 7 PID: 24321 at fs/direct-io.c:274 dio_complete+0x16f/0x1f0 [ 6235.560858] Modules linked in: dm_flakey loop rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache af_packet br_netfilter bridge stp llc iscsi_ibft iscsi_boot_sysfs btrfs xor zstd_decompress zstd_compress i2c_algo_bit drm_kms_helper xxhash zlib_deflate raid6_pq syscopyarea sysfillrect sysimgblt fb_sys_fops ttm tg3 drm dm_mod dax ptp kvm_amd pps_core kvm libphy tpm_infineon mptctl shpchp k10temp tpm_tis tpm_tis_core button i2c_piix4 tpm pcspkr irqbypass acpi_cpufreq ext4 mbcache jbd2 sr_mod cdrom ohci_pci ehci_pci ohci_hcd mptsas ehci_hcd scsi_transport_sas ata_generic mptscsih serio_raw mptbase usbcore sata_svw pata_serverworks sg scsi_dh_rdac scsi_dh_emc scsi_dh_alua [ 6235.560942] CPU: 7 PID: 24321 Comm: kworker/7:1 Not tainted 4.14.0-rc4-1.ge195904-vanilla+ #71 [ 6235.560944] Hardware name: empty empty/S3993, BIOS PAQEX0-3 02/24/2008 [ 6235.560950] Workqueue: dio/sdb6 dio_aio_complete_work [ 6235.560953] task: ffff894fe0bd8300 task.stack: ffffb45742f7c000 [ 6235.560957] RIP: 0010:dio_complete+0x16f/0x1f0 [ 6235.560959] RSP: 0018:ffffb45742f7fde8 EFLAGS: 00010286 [ 6235.560968] RAX: 00000000fffffff0 RBX: ffff894fd1e3a680 RCX: ffff894fe0bd8300 [ 6235.560970] RDX: 0000000000000000 RSI: 00000000000002b4 RDI: ffffffffaba438e9 [ 6235.560971] RBP: ffffb45742f7fe10 R08: 0000000000000000 R09: 0000000000000025 [ 6235.560973] R10: 0000000000000000 R11: 0000000000000000 R12: 000000000001e000 [ 6235.560974] R13: 000000000001e000 R14: 0000000000007000 R15: 0000000000000001 [ 6235.560977] FS: 0000000000000000(0000) GS:ffff894fefdc0000(0000) knlGS:0000000000000000 [ 6235.560978] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6235.560980] CR2: 00007fe1e1dfb610 CR3: 0000000213ee7000 CR4: 00000000000006e0 [ 6235.560982] Call Trace: [ 6235.561075] dio_aio_complete_work+0x1c/0x20 [ 6235.561082] process_one_work+0x1d8/0x620 [ 6235.561085] ? process_one_work+0x14b/0x620 [ 6235.561092] worker_thread+0x4d/0x3c0 [ 6235.561097] ? trace_hardirqs_on+0xd/0x10 [ 6235.561105] kthread+0x152/0x190 [ 6235.561107] ? process_one_work+0x620/0x620 [ 6235.561111] ? kthread_create_on_node+0x40/0x40 [ 6235.561116] ? do_syscall_64+0x69/0x180 [ 6235.561122] ret_from_fork+0x2a/0x40 [ 6235.561131] Code: 48 83 bf 00 01 00 00 00 0f 84 37 ff ff ff 4b 8d 54 34 ff 4c 89 f6 48 c1 fe 0c 48 c1 fa 0c e8 49 82 f2 ff 85 c0 0f 84 1a ff ff ff <0f> ff e9 13 ff ff ff 48 81 c7 e0 00 00 00 be 09 00 00 00 e8 79 [ 6235.561179] ---[ end trace ba80cd81f19cb389 ]--- I've added Chris and Bo to CC if they have more to say about the specifics of dio and buffered writes as implemented in btrfs.