Re: kern/50375: layerfs (nullfs) locking problem leading to livelock

[Jeff Rizzo <riz%tastylime.net@localhost>]

The following reply was made to PR kern/50375; it has been noted by GNATS.

From: Jeff Rizzo <riz%tastylime.net@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/50375: layerfs (nullfs) locking problem leading to livelock
Date: Thu, 29 Oct 2015 07:19:31 -0700

 (gdb) print *((struct layer_node *)0x966580b0)
 $3 = {layer_lowervp = 0x92314df8, layer_vnode = 0x9246d850, layer_flags = 0}
 (gdb) print *((struct layer_node *)0x966580b0)->layer_lowervp
 $4 = {v_uobj = {vmobjlock = 0x91f3f640, pgops = 0x81423cc0 
 <uvm_vnodeops>, memq = {tqh_first = 0x0, tqh_last = 0x92314e00}, 
 uo_npages = 0, uo_refs = 5, rb_tree = {
        rbt_root = 0x0, rbt_ops = 0x81423c00 <uvm_page_tree_ops>, 
 rbt_minmax = {0x0, 0x0}}, uo_ubc = {lh_first = 0x0}}, v_cv = {cv_opaque 
 = {0x0, 0x92314e24, 0x8146e51c}},
    v_size = 2048, v_writesize = 2048, v_iflag = 0, v_vflag = 48, v_uflag 
 = 0, v_numoutput = 0, v_writecount = 0, v_holdcnt = 1, v_synclist_slot = 
 0, v_mount = 0x920d3008,
    v_op = 0x9159a548, v_freelist = {tqe_next = 0x93142430, tqe_prev = 
 0x940c2fbc}, v_freelisthd = 0x0, v_mntvnodes = {tqe_next = 0x966c42f0, 
 tqe_prev = 0x92f3c428},
    v_cleanblkhd = {lh_first = 0x94d56328}, v_dirtyblkhd = {lh_first = 
 0x0}, v_synclist = {tqe_next = 0x0, tqe_prev = 0x0}, v_dnclist = 
 {lh_first = 0x93489880}, v_nclist = {
      lh_first = 0x93496380}, v_un = {vu_mountedhere = 0x0, vu_socket = 
 0x0, vu_specnode = 0x0, vu_fifoinfo = 0x0, vu_ractx = 0x0}, v_type = 
 VDIR, v_tag = VT_UFS, v_lock = {
      rw_owner = 2507571303}, v_data = 0x92f40198, v_klist = {slh_first = 
 0x0}}