1. 17 Jul, 2019 1 commit
    • Qu Wenruo's avatar
      btrfs: inode: Don't compress if NODATASUM or NODATACOW set · 42c16da6
      Qu Wenruo authored
      As btrfs(5) specified:
      
      	Note
      	If nodatacow or nodatasum are enabled, compression is disabled.
      
      If NODATASUM or NODATACOW set, we should not compress the extent.
      
      Normally NODATACOW is detected properly in run_delalloc_range() so
      compression won't happen for NODATACOW.
      
      However for NODATASUM we don't have any check, and it can cause
      compressed extent without csum pretty easily, just by:
        mkfs.btrfs -f $dev
        mount $dev $mnt -o nodatasum
        touch $mnt/foobar
        mount -o remount,datasum,compress $mnt
        xfs_io -f -c "pwrite 0 128K" $mnt/foobar
      
      And in fact, we have a bug report about corrupted compressed extent
      without proper data checksum so even RAID1 can't recover the corruption.
      (https://bugzilla.kernel.org/show_bug.cgi?id=199707)
      
      Running compression without proper checksum could cause more damage when
      corruption happens, as compressed data could make the whole extent
      unreadable, so there is no need to allow compression for
      NODATACSUM.
      
      The fix will refactor the inode compression check into two parts:
      
      - inode_can_compress()
        As the hard requirement, checked at btrfs_run_delalloc_range(), so no
        compression will happen for NODATASUM inode at all.
      
      - inode_need_compress()
        As the soft requirement, checked at btrfs_run_delalloc_range() and
        compress_file_range().
      Reported-by: default avatarJames Harvey <jamespharvey20@gmail.com>
      CC: stable@vger.kernel.org # 4.4+
      Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
      Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
      Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
      42c16da6
  2. 05 Jul, 2019 1 commit
  3. 04 Jul, 2019 5 commits
  4. 02 Jul, 2019 33 commits