• Paul Walmsley's avatar
    Revert "lockdep: check that no locks held at freeze time" · dbf520a9
    Paul Walmsley authored
    This reverts commit 6aa97070.
    
    Commit 6aa97070 ("lockdep: check that no locks held at freeze time")
    causes problems with NFS root filesystems.  The failures were noticed on
    OMAP2 and 3 boards during kernel init:
    
      [ BUG: swapper/0/1 still has locks held! ]
      3.9.0-rc3-00344-ga937536b #1 Not tainted
      -------------------------------------
      1 lock held by swapper/0/1:
       #0:  (&type->s_umount_key#13/1){+.+.+.}, at: [<c011e84c>] sget+0x248/0x574
    
      stack backtrace:
        rpc_wait_bit_killable
        __wait_on_bit
        out_of_line_wait_on_bit
        __rpc_execute
        rpc_run_task
        rpc_call_sync
        nfs_proc_get_root
        nfs_get_root
        nfs_fs_mount_common
        nfs_try_mount
        nfs_fs_mount
        mount_fs
        vfs_kern_mount
        do_mount
        sys_mount
        do_mount_root
        mount_root
        prepare_namespace
        kernel_init_freeable
        kernel_init
    
    Although the rootfs mounts, the system is unstable.  Here's a transcript
    from a PM test:
    
      http://www.pwsan.com/omap/testlogs/test_v3.9-rc3/20130317194234/pm/37xxevm/37xxevm_log.txt
    
    Here's what the test log should look like:
    
      http://www.pwsan.com/omap/testlogs/test_v3.8/20130218214403/pm/37xxevm/37xxevm_log.txt
    
    Mailing list discussion is here:
    
      http://lkml.org/lkml/2013/3/4/221
    
    Deal with this for v3.9 by reverting the problem commit, until folks can
    figure out the right long-term course of action.
    Signed-off-by: default avatarPaul Walmsley <paul@pwsan.com>
    Cc: Mandeep Singh Baines <msb@chromium.org>
    Cc: Jeff Layton <jlayton@redhat.com>
    Cc: Shawn Guo <shawn.guo@linaro.org>
    Cc: <maciej.rutecki@gmail.com>
    Cc: Fengguang Wu <fengguang.wu@intel.com>
    Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Ben Chan <benchan@chromium.org>
    Cc: Oleg Nesterov <oleg@redhat.com>
    Cc: Tejun Heo <tj@kernel.org>
    Cc: Rafael J. Wysocki <rjw@sisk.pl>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    dbf520a9
lockdep.c 104 KB