Comment # 1 on bug 1019792 from Gang He

The first node back trace,

     
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������2*[ssh]
        ���                                                               
������{mpirun}

ocfs2dev1:~ # cat /proc/20337/stack
[<ffffffff8c263e67>] __wait_on_buffer+0x27/0x30
[<ffffffffc06ce143>] ocfs2_read_blocks+0x3f3/0x630 [ocfs2]
[<ffffffffc070c4f3>] ocfs2_read_group_descriptor+0x43/0x130 [ocfs2]
[<ffffffffc070cfb3>] ocfs2_search_chain+0xd3/0x8e0 [ocfs2]
[<ffffffffc070dc14>] ocfs2_claim_suballoc_bits+0x454/0x720 [ocfs2]
[<ffffffffc070eae4>] __ocfs2_claim_clusters+0xa4/0x290 [ocfs2]
[<ffffffffc07104cc>] ocfs2_claim_clusters+0x1c/0x20 [ocfs2]
[<ffffffffc06f08a1>] ocfs2_local_alloc_slide_window+0x281/0x8f0 [ocfs2]
[<ffffffffc06f2216>] ocfs2_reserve_local_alloc_bits+0x1b6/0x2b0 [ocfs2]
[<ffffffffc07101e0>] ocfs2_reserve_clusters_with_limit+0x110/0x3c0 [ocfs2]
[<ffffffffc0710705>] ocfs2_lock_allocators+0x185/0x200 [ocfs2]
[<ffffffffc06cb50e>] ocfs2_write_begin_nolock+0xb9e/0x18d0 [ocfs2]
[<ffffffffc06cc342>] ocfs2_write_begin+0x102/0x1c0 [ocfs2]
[<ffffffff8c1a086a>] generic_perform_write+0xba/0x190
[<ffffffff8c1a3185>] __generic_file_write_iter+0x185/0x1d0
[<ffffffffc06e5c2a>] ocfs2_file_write_iter+0x43a/0xaa0 [ocfs2]
[<ffffffff8c22be37>] __vfs_write+0xc7/0x140
[<ffffffff8c22cfc5>] vfs_write+0xb5/0x1a0
[<ffffffff8c22e466>] SyS_pwrite64+0x76/0x90
[<ffffffff8c71937b>] entry_SYSCALL_64_fastpath+0x1e/0xad
[<ffffffffffffffff>] 0xffffffffffffffff