From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from prv3-mh.provo.novell.com ([137.65.250.26]:37293 "EHLO prv3-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750886AbeAVFvL (ORCPT ); Mon, 22 Jan 2018 00:51:11 -0500 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Cc: nborisov@suse.com Subject: [PATCH v2] btrfs: Add chunk allocation ENOSPC debug message for enospc_debug mount option Date: Mon, 22 Jan 2018 13:50:54 +0800 Message-Id: <20180122055054.7933-1-wqu@suse.com> In-Reply-To: <20180115061352.13799-1-wqu@suse.com> References: <20180115061352.13799-1-wqu@suse.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: Enospc_debug makes extent allocator to print more debug messages, however for chunk allocation, there is no debug message for enospc_debug at all. This patch will add message for the following parts of chunk allocator: 1) No rw device at all Quite rare, but at least output one message for this case. 2) No enough space for some device This debug message is quite handy for unbalanced disks with stripe based profiles (RAID0/10/5/6). 3) Not enough free devices This debug message should tell us if current chunk allocator is working correctly on minimal device requirement. Although under most case, we will hit other ENOSPC before we even hit a chunk allocator ENOSPC, but such debug info won't help. Signed-off-by: Qu Wenruo --- v2: Unify all message level to btrfs_debug(). More meaningful message if we don't have enough device. --- fs/btrfs/volumes.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index a25684287501..86cae6a15b1e 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4622,8 +4622,11 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, BUG_ON(!alloc_profile_is_valid(type, 0)); - if (list_empty(&fs_devices->alloc_list)) + if (list_empty(&fs_devices->alloc_list)) { + if (btrfs_test_opt(info, ENOSPC_DEBUG)) + btrfs_debug(info, "%s: No writable device", __func__); return -ENOSPC; + } index = __get_raid_index(type); @@ -4705,8 +4708,14 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, if (ret == 0) max_avail = max_stripe_size * dev_stripes; - if (max_avail < BTRFS_STRIPE_LEN * dev_stripes) + if (max_avail < BTRFS_STRIPE_LEN * dev_stripes) { + if (btrfs_test_opt(info, ENOSPC_DEBUG)) + btrfs_debug(info, + "%s: devid %llu has no free space, have=%llu want=%u", + __func__, device->devid, max_avail, + BTRFS_STRIPE_LEN * dev_stripes); continue; + } if (ndevs == fs_devices->rw_devices) { WARN(1, "%s: found more than %llu devices\n", @@ -4731,6 +4740,12 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) { ret = -ENOSPC; + if (btrfs_test_opt(info, ENOSPC_DEBUG)) { + btrfs_debug(info, + "%s: not enough devices with free space: have=%d minimal required=%d", + __func__, ndevs, min(devs_min, + devs_increment * sub_stripes)); + } goto error; } -- 2.15.1