From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-31.italiaonline.it ([212.48.25.159]:51447 "EHLO libero.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750852AbcCHTYj (ORCPT ); Tue, 8 Mar 2016 14:24:39 -0500 Reply-To: kreijack@inwind.it Subject: Re: [PATCH v2] Btrfs: Show a warning message if one of objectid reaches its highest value References: <56DCF015.9060703@jp.fujitsu.com> To: Satoru Takeuchi , "linux-btrfs@vger.kernel.org" From: Goffredo Baroncelli Message-ID: <56DF26F4.2010508@inwind.it> Date: Tue, 8 Mar 2016 20:24:36 +0100 MIME-Version: 1.0 In-Reply-To: <56DCF015.9060703@jp.fujitsu.com> Content-Type: text/plain; charset=iso-2022-jp Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 2016-03-07 04:05, Satoru Takeuchi wrote: > - It's better to show a warning message for the exceptional case > that one of objectid (in most case, inode number) reaches its > highest value. Show this message only once to avoid filling > dmesg with it. > - EOVERFLOW is more proper return value for this case. > ENOSPC is for "No space left on device" case and objectid isn't > related to any device. > > Signed-off-by: Satoru Takeuchi > --- > This patch can be applied to 4.5-rc7 > --- > fs/btrfs/inode-map.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c > index e50316c..f5e3228 100644 > --- a/fs/btrfs/inode-map.c > +++ b/fs/btrfs/inode-map.c > @@ -556,7 +556,15 @@ int btrfs_find_free_objectid(struct btrfs_root *root, u64 *objectid) > mutex_lock(&root->objectid_mutex); > > if (unlikely(root->highest_objectid >= BTRFS_LAST_FREE_OBJECTID)) { > - ret = -ENOSPC; > + static bool __warned = false; Please, don't use a static GLOBAL variable. I suggest to move to a "per filesystem" variables for two main reasons: 1) if in the (very unlikely) case where two different filesystems reach BTRFS_LAST_FREE_OBJECTID, the first error will hide the second one. 2) if you umount and remount the filesystem the error is not shown anymore. A module unload/load or a reboot is required. If something strange happens, one of the first thing that the user does, is to umount/remount the filesystem. But the error is not show anymore. This could complicate the diagnosis of the problem. > + > + if (unlikely(!__warned)) { > + btrfs_warn(root->fs_info, > + "The objectid of root %llu reaches its highest value.\n", > + root->root_key.objectid); > + __warned = true; > + } > + ret = -EOVERFLOW; > goto out; > } > -- gpg @keyserver.linux.it: Goffredo Baroncelli Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5