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 69279EC8742 for ; Thu, 7 Sep 2023 17:53:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239386AbjIGRxL (ORCPT ); Thu, 7 Sep 2023 13:53:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237564AbjIGRxK (ORCPT ); Thu, 7 Sep 2023 13:53:10 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E16C61717; Thu, 7 Sep 2023 10:52:40 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 77BADC433CB; Thu, 7 Sep 2023 16:35:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694104540; bh=UBuzMRShgw1qGwKcp5icerNaUWSaGcKJhV1zuNEabRs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qYQrgorUVUYtbEBnqMCJk+ppdOr7JCB+Ug4vURzNnaB6+rt6DIM+EH51CBJHQPR5T yYSfxUmicOlsHCdIld4Uv8yS7oQVyJsNJVu/66RcCBYpxw07ZuA5KmH3waiiwIuPIV 6oSNm9LlVdLtv7ZgOo0Lw5/eTTUox0fZ/FctdWDXrshlwkaANbHg3RnMp0uBQ0CESu U2+TbLuuG+PTnroavQpwFnM5BF//nAGseNSXdyj3jSut+bAZ7vJ58oz6m0fqn6NjBR h1p91iPsOfVryPPs4TchcwRolehJYodDEHtVclBQx4//CTMm8xXSE16QC9KcUYVNoq j0u/b4NAFPyKQ== Date: Thu, 7 Sep 2023 17:35:37 +0100 From: Filipe Manana To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Filipe Manana , David Sterba , clm@fb.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org Subject: Re: [PATCH AUTOSEL 6.5 3/6] btrfs: return real error when orphan cleanup fails due to a transaction abort Message-ID: References: <20230907154338.3421582-1-sashal@kernel.org> <20230907154338.3421582-3-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230907154338.3421582-3-sashal@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, Sep 07, 2023 at 11:43:34AM -0400, Sasha Levin wrote: > From: Filipe Manana > > [ Upstream commit a7f8de500e28bb227e02a7bd35988cf37b816c86 ] Please don't add this patch to any stable release. Besides not being that important for stable, backporting it alone would not be correct as it depends on: commit ae3364e5215bed9ce89db6b0c2d21eae4b66f4ae Author: Filipe Manana Date: Wed Jul 26 16:57:04 2023 +0100 btrfs: store the error that turned the fs into error state Thanks. > > During mount we will call btrfs_orphan_cleanup() to remove any inodes that > were previously deleted (have a link count of 0) but for which we were not > able before to remove their items from the subvolume tree. The removal of > the items will happen by triggering eviction, when we do the final iput() > on them at btrfs_orphan_cleanup(), which will end in the loop at > btrfs_evict_inode() that truncates inode items. > > In a dire situation we may have a transaction abort due to -ENOSPC when > attempting to truncate the inode items, and in that case the orphan item > (key type BTRFS_ORPHAN_ITEM_KEY) will remain in the subvolume tree and > when we hit the next iteration of the while loop at btrfs_orphan_cleanup() > we will find the same orphan item as before, and then we will return > -EINVAL from btrfs_orphan_cleanup() through the following if statement: > > if (found_key.offset == last_objectid) { > btrfs_err(fs_info, > "Error removing orphan entry, stopping orphan cleanup"); > ret = -EINVAL; > goto out; > } > > This makes the mount operation fail with -EINVAL, when it should have been > -ENOSPC. This is confusing because -EINVAL might lead a user into thinking > it provided invalid mount options for example. > > An example where this happens: > > $ mount test.img /mnt > mount: /mnt: wrong fs type, bad option, bad superblock on /dev/loop0, missing codepage or helper program, or other error. > > $ dmesg > [ 2542.356934] BTRFS: device fsid 977fff75-1181-4d2b-a739-384fa710d16e devid 1 transid 47409973 /dev/loop0 scanned by mount (4459) > [ 2542.357451] BTRFS info (device loop0): using crc32c (crc32c-intel) checksum algorithm > [ 2542.357461] BTRFS info (device loop0): disk space caching is enabled > [ 2542.742287] BTRFS info (device loop0): auto enabling async discard > [ 2542.764554] BTRFS info (device loop0): checking UUID tree > [ 2551.743065] ------------[ cut here ]------------ > [ 2551.743068] BTRFS: Transaction aborted (error -28) > [ 2551.743149] WARNING: CPU: 7 PID: 215 at fs/btrfs/block-group.c:3494 btrfs_write_dirty_block_groups+0x397/0x3d0 [btrfs] > [ 2551.743311] Modules linked in: btrfs blake2b_generic (...) > [ 2551.743353] CPU: 7 PID: 215 Comm: kworker/u24:5 Not tainted 6.4.0-rc6-btrfs-next-134+ #1 > [ 2551.743356] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014 > [ 2551.743357] Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs] > [ 2551.743405] RIP: 0010:btrfs_write_dirty_block_groups+0x397/0x3d0 [btrfs] > [ 2551.743449] Code: 8b 43 0c (...) > [ 2551.743451] RSP: 0018:ffff982c005a7c40 EFLAGS: 00010286 > [ 2551.743452] RAX: 0000000000000000 RBX: ffff88fc6e44b400 RCX: 0000000000000000 > [ 2551.743453] RDX: 0000000000000002 RSI: ffffffff8dff0878 RDI: 00000000ffffffff > [ 2551.743454] RBP: ffff88fc51817208 R08: 0000000000000000 R09: ffff982c005a7ae0 > [ 2551.743455] R10: 0000000000000001 R11: 0000000000000001 R12: ffff88fc43d2e570 > [ 2551.743456] R13: ffff88fc43d2e400 R14: ffff88fc8fb08ee0 R15: ffff88fc6e44b530 > [ 2551.743457] FS: 0000000000000000(0000) GS:ffff89035fbc0000(0000) knlGS:0000000000000000 > [ 2551.743458] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 2551.743459] CR2: 00007fa8cdf2f6f4 CR3: 0000000124850003 CR4: 0000000000370ee0 > [ 2551.743462] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 2551.743463] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 2551.743464] Call Trace: > [ 2551.743472] > [ 2551.743474] ? __warn+0x80/0x130 > [ 2551.743478] ? btrfs_write_dirty_block_groups+0x397/0x3d0 [btrfs] > [ 2551.743520] ? report_bug+0x1f4/0x200 > [ 2551.743523] ? handle_bug+0x42/0x70 > [ 2551.743526] ? exc_invalid_op+0x14/0x70 > [ 2551.743528] ? asm_exc_invalid_op+0x16/0x20 > [ 2551.743532] ? btrfs_write_dirty_block_groups+0x397/0x3d0 [btrfs] > [ 2551.743574] ? _raw_spin_unlock+0x15/0x30 > [ 2551.743576] ? btrfs_run_delayed_refs+0x1bd/0x200 [btrfs] > [ 2551.743609] commit_cowonly_roots+0x1e9/0x260 [btrfs] > [ 2551.743652] btrfs_commit_transaction+0x42e/0xfa0 [btrfs] > [ 2551.743693] ? __pfx_autoremove_wake_function+0x10/0x10 > [ 2551.743697] flush_space+0xf1/0x5d0 [btrfs] > [ 2551.743743] ? _raw_spin_unlock+0x15/0x30 > [ 2551.743745] ? finish_task_switch+0x91/0x2a0 > [ 2551.743748] ? _raw_spin_unlock+0x15/0x30 > [ 2551.743750] ? btrfs_get_alloc_profile+0xc9/0x1f0 [btrfs] > [ 2551.743793] btrfs_async_reclaim_metadata_space+0xe1/0x230 [btrfs] > [ 2551.743837] process_one_work+0x1d9/0x3e0 > [ 2551.743844] worker_thread+0x4a/0x3b0 > [ 2551.743847] ? __pfx_worker_thread+0x10/0x10 > [ 2551.743849] kthread+0xee/0x120 > [ 2551.743852] ? __pfx_kthread+0x10/0x10 > [ 2551.743854] ret_from_fork+0x29/0x50 > [ 2551.743860] > [ 2551.743861] ---[ end trace 0000000000000000 ]--- > [ 2551.743863] BTRFS info (device loop0: state A): dumping space info: > [ 2551.743866] BTRFS info (device loop0: state A): space_info DATA has 126976 free, is full > [ 2551.743868] BTRFS info (device loop0: state A): space_info total=13458472960, used=13458137088, pinned=143360, reserved=0, may_use=0, readonly=65536 zone_unusable=0 > [ 2551.743870] BTRFS info (device loop0: state A): space_info METADATA has -51625984 free, is full > [ 2551.743872] BTRFS info (device loop0: state A): space_info total=771751936, used=770146304, pinned=1605632, reserved=0, may_use=51625984, readonly=0 zone_unusable=0 > [ 2551.743874] BTRFS info (device loop0: state A): space_info SYSTEM has 14663680 free, is not full > [ 2551.743875] BTRFS info (device loop0: state A): space_info total=14680064, used=16384, pinned=0, reserved=0, may_use=0, readonly=0 zone_unusable=0 > [ 2551.743877] BTRFS info (device loop0: state A): global_block_rsv: size 53231616 reserved 51544064 > [ 2551.743878] BTRFS info (device loop0: state A): trans_block_rsv: size 0 reserved 0 > [ 2551.743879] BTRFS info (device loop0: state A): chunk_block_rsv: size 0 reserved 0 > [ 2551.743880] BTRFS info (device loop0: state A): delayed_block_rsv: size 0 reserved 0 > [ 2551.743881] BTRFS info (device loop0: state A): delayed_refs_rsv: size 786432 reserved 0 > [ 2551.743886] BTRFS: error (device loop0: state A) in btrfs_write_dirty_block_groups:3494: errno=-28 No space left > [ 2551.743911] BTRFS info (device loop0: state EA): forced readonly > [ 2551.743951] BTRFS warning (device loop0: state EA): could not allocate space for delete; will truncate on mount > [ 2551.743962] BTRFS error (device loop0: state EA): Error removing orphan entry, stopping orphan cleanup > [ 2551.743973] BTRFS warning (device loop0: state EA): Skipping commit of aborted transaction. > [ 2551.743989] BTRFS error (device loop0: state EA): could not do orphan cleanup -22 > > So make the btrfs_orphan_cleanup() return the value of BTRFS_FS_ERROR(), > if it's set, and -EINVAL otherwise. > > For that same example, after this change, the mount operation fails with > -ENOSPC: > > $ mount test.img /mnt > mount: /mnt: mount(2) system call failed: No space left on device. > > Signed-off-by: Filipe Manana > Signed-off-by: David Sterba > Signed-off-by: Sasha Levin > --- > fs/btrfs/inode.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index aa090b0b5d298..02d9640699b80 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -3662,9 +3662,16 @@ int btrfs_orphan_cleanup(struct btrfs_root *root) > */ > > if (found_key.offset == last_objectid) { > + /* > + * We found the same inode as before. This means we were > + * not able to remove its items via eviction triggered > + * by an iput(). A transaction abort may have happened, > + * due to -ENOSPC for example, so try to grab the error > + * that lead to a transaction abort, if any. > + */ > btrfs_err(fs_info, > "Error removing orphan entry, stopping orphan cleanup"); > - ret = -EINVAL; > + ret = BTRFS_FS_ERROR(fs_info) ?: -EINVAL; > goto out; > } > > -- > 2.40.1 >