> After powering up, the GEdit document is intact and contains the latest > content, whereas the LibreOffice document is gone forever.
Thanks for testing. This is as expected, unless we use 'rename' - and the code needs fixing to do that. *Unfortunately* the code is far worse than a rats nest here. Using 'rename' seems like an easy & trivial thing to do right ? it is the elegant solution to avoiding 'fsync' - but this is not really so. It is fairly easy to create a file-system for which we have no ability to create files in the same directory that can be renamed over the top - and finding other directories on similar file-systems for which 'rename' can validly replace a file in another directory is a twisted mess of nastiness. In these cases we -have- to open that file, write stuff to it - and then we can't call fsync because it is a "bust your system interactivity, break your burning DVD, jitter your sound playback, and make people think LibreOffice kills babies" syscall on old file-systems, where 'old' means 'widely deployed' :-) Worse - there is no standard library out there that wraps 'fsync' into a 'sane_fsync' that will tell us what file-systems underlies the file, and ensure that we are only calling fsync where it is safe (cf. above). 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. Which would prolly solve the problem. AFAICS dev_t's are pretty useless; perhaps we'd need to parse /proc/mounts and combine that with the horrible stat walk we already do to determine file-system type, and then start doing string munging: "ext4" - safe to 'fsync', "btrfs" - prolly a good idea to 'fsync' - or is it ? perhaps only > some version of btrfs, and for ext3/ext2 etc. there is no need - they tend not to wantonly loose your data ;-) -- 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
