• Josef Bacik's avatar
    Btrfs: unset DCACHE_DISCONNECTED when mounting default subvol · 3a0dfa6a
    Josef Bacik authored
    A user was running into errors from an NFS export of a subvolume that had a
    default subvol set.  When we mount a default subvol we will use d_obtain_alias()
    to find an existing dentry for the subvolume in the case that the root subvol
    has already been mounted, or a dummy one is allocated in the case that the root
    subvol has not already been mounted.  This allows us to connect the dentry later
    on if we wander into the path.  However if we don't ever wander into the path we
    will keep DCACHE_DISCONNECTED set for a long time, which angers NFS.  It doesn't
    appear to cause any problems but it is annoying nonetheless, so simply unset
    DCACHE_DISCONNECTED in the get_default_root case and switch btrfs_lookup() to
    use d_materialise_unique() instead which will make everything play nicely
    together and reconnect stuff if we wander into the defaul subvol path from a
    different way.  With this patch I'm no longer getting the NFS errors when
    exporting a volume that has been mounted with a default subvol set.  Thanks,
    
    cc: bfields@fieldses.org
    cc: ebiederm@xmission.com
    Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
    Acked-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
    Signed-off-by: default avatarChris Mason <clm@fb.com>
    3a0dfa6a
inode.c 237 KB