I've just seen this too on Fedora 16 while I was investigating an NFS issue. I was trying to copy a file from an NFS mount to a btrfs partition. The NFS transfers for large files were occurring in bursts for some reason and I was aborting the copy at times. This NFS problem was not related to btrfs (cat NFS file > /dev/null was also bursting and slow).
Originally I ran 3.2.1-3.fc16, but just upgraded to 3.2.7-1.fc16. The file system was formatted with 3.2.1 originally. I can't say for sure what caused this - whether it was the NFS being slow, the copy being interrupted, or btrfs itself. Regards, Nik On Mon, Feb 27, 2012 at 9:03 AM, David Sterba <d...@jikos.cz> wrote: > On Sat, Feb 25, 2012 at 09:14:01AM +1030, Jordan Windsor wrote: >> I'm running Ubuntu under KVM, with btrfs on the host where the >> Qemu/KVM image is stored, the VM was also running at the time. I was >> going to check something unrelated in the dmesg output, as I did that >> I noticed some errors in it about btrfs here they are: >> >> >> [ 4294.431807] btrfs: block rsv returned -28 >> [ 4294.431811] ------------[ cut here ]------------ >> [ 4294.431831] WARNING: at fs/btrfs/extent-tree.c:5985 > > This is a warning and it shows up from time to time, accross recent > releases. > >> This didn't cause any crashes or related issues, also unrelated (I >> think?) is that I get very low performance (about 5MBps according to >> iostat) in a guest under Qemu/KVM. >> 3.2.7-1-ARCH x86_64 Arch Linux > > Yes, the performance goes down as some pathological should-not-happen > code path is taken. I myself haven't seen this error recently during > testing, but at the time I did, it slowed down the machine for a while, > ie. it's not a inifinite loop. Seems there's a dark corner of > space reservations left for Josef. > > > david > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
