(In reply to comment #13) > If some > enterprising kernel hacker wants to create a nice, ultra-liberally licensed > library that turns a dev_t into a boolean: int is_it_safe_to_fsync (dev_t *t); > then I'd be more than happy to see it used un-conditionally in our > system-abstraction for Unix / Linux.
I was actually looking into that recently as part of another project and it's pretty easy. Basically, 1) Stat the file to get the st_dev. 2) Stat each file in /dev/disk/by-uuid to find one with a matching st_rdev. 3) Run realpath() on that file. Now you have the device file holding the filesystem. >From there you can easily look up the filesystem type in many places, e.g. /etc/mtab, /proc/fs, or /sys/fs. Probably /etc/mtab is your best bet since it is a generic UNIX thing. On non-Linux or on Linux without udev you could fall back to stat'ing each file in /dev rather than /dev/disk/by-uuid. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to libreoffice in Ubuntu. https://bugs.launchpad.net/bugs/817326 Title: [Upstream] Previously-saved LibreOffice document lost by power outage (became 0 bytes long) - LibreOffice should call fsync Status in LibreOffice Productivity Suite: Confirmed Status in “libreoffice” package in Ubuntu: Confirmed Bug description: I was working on a document in LibreOffice today while my battery was low and so I was frequently saving, which I thought would help me if I lost power. However, when I eventually did lose power and later rebooted, the document had become 0 bytes long. LibreOffice was not able to restore the auto-saved copy either. As a result, I have lost a whole week of notes for one of my courses. After researching online, it seems that this is caused by the application not calling fsync() (or fdatasync()) when saving files. Due to delayed allocation in modern filesystems, there is no guarantee that the new file's data has actually been written to disk unless the application calls fsync. So if an app writes a new file and replaces the old one with it without fsync'ing the new one first then there is a window of opportunity during which a power failure will result in the loss of BOTH versions of the file. In ext4 this window is also much larger than in ext3. Theodore Tso blogged about this at http://ldn.linuxfoundation.org /blog-entry/delayed-allocation-and-zero-length-file-problem and http://www.linuxfoundation.org/news- media/blogs/browse/2009/03/don%E2%80%99t-fear-fsync. He strongly recommends to call fsync in this situation. Please update LibreOffice to fsync() saved files so that other users do not lose their data like I did. ProblemType: Bug DistroRelease: Ubuntu 11.04 Package: libreoffice-core 1:3.3.2-1ubuntu5 ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2 Uname: Linux 2.6.38-8-generic x86_64 Architecture: amd64 Date: Wed Jul 27 21:37:02 2011 InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429) ProcEnviron: LANGUAGE=en_US:en LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: libreoffice UpgradeStatus: Upgraded to natty on 2011-04-29 (89 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/df-libreoffice/+bug/817326/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
