From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josef Bacik Subject: Re: BTRFS should increase the hard-link in the same directory limit Date: Mon, 22 Aug 2011 10:54:21 -0400 Message-ID: <4E526D9D.8010202@redhat.com> References: <874o1aztkm.fsf-genuine-vii@john.fremlin.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-btrfs@vger.kernel.org To: John Fremlin Return-path: In-Reply-To: <874o1aztkm.fsf-genuine-vii@john.fremlin.org> List-ID: On 08/21/2011 11:13 AM, John Fremlin wrote: > It seems a priori that there should not be any need for more than 256 > names for the same file in the same directory. However, the GNUS > mailreader's nnmaildir backend uses hardlinks to mark email messages > read, and instead of creating a separate inode for each marked > message, uses a hardlink to a single markfile. This means that there > maybe thousands of hardlinks to the same inode in a single directory. > > This is not unreasonable as the obvious workaround is to wastefully > create more inodes. > > This restriction causes btrfs-convert 0.19 to crash out with a segfault and > no helpful message: something like btrfs-convert: segfault at > ffffffffcfb25fb9 ip 000000000040f9f1 sp 00007fffddefb398 error 6 in > btrfs-convert[400000+21000]. > > Is there any plan to alleviate this unfortunate limit (or at least make > btrfs-convert give the location of the file which causes it to fail?). It's a disk format change, something we don't do lightly. Josef