On Tue, 7 Oct 2014 04:04:48 AM James Harper wrote:
Watch out with 3.17 then, there are early reports that it's broken btrfs send.>
Broken how?
Mentioned on the linux-btrfs list: # After upgrading to kernel 3.17 btrfs send has stopped working. # # ERROR: send ioctl failed with -5: Input/output error # # The following message is printed by kernel: # # [75322.782197] BTRFS error (device sda2): did not find backref # in send_root. inode=461, offset=0, disk_byte=1094713344 # found extent=1094713344 # # btrfs inspect-internal inode-resolve -v 461 /u00/root.snapshot returns: # # /var/log/emerge-fetch.log # # After removing this file, the error moves on to another file. He tried some things from Chris Mason and then reported: # I just tried downgrading to 3.16.3 again. In 3.16.3 btrfs send # is working without any problem. Afterwards I upgraded again # to 3.17 and the problem reappeared. So the problem seems # to be kernel version related. Chris M. asked him to revert a specific commit also mentioned in this section of another issue that's emerged in 3.17, below. # Just tried it and I confirm filefrag's call to ioctl FS_IOC_FIEMAP # fails with -EEXIST. # # It's actually a known issue affecting any of the 3.17 RCs (except RC1). # The extent map manipulation/merging is broken for some cases. Try # with this 2 patches on top of 3.17-rcX: # # https://patchwork.kernel.org/patch/4929981/ # https://patchwork.kernel.org/patch/4945191/ # # Or, alternatively, reverting this patch: # https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=5... # # Someone else reported on this list a write/pwrite/writev failure with # errno EEXIST too (and apparently caused by the same reason). # # This broken extent map handling is serious IMHO, it can make fsync # log bogus extent items for example, amongst other possible bad and # weird things. The OP in this case reported that the patches fixed his issue, didn't comment on reverting this commit. Hopefully these can get tracked down quickly. ;-( cheers, Chris -- Chris Samuel : http://www.csamuel.org/ : Melbourne, VIC