Revert "lockdep: check that no locks held at freeze time"

This reverts commit 6aa9707099.

Commit 6aa9707099 ("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-ga937536 #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:

  2013031719/pm/37xxevm/37xxevm_log.txt

Here's what the test log should look like:

  2013021821/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: Paul 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: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Paul Walmsley 2013-03-31 00:04:40 +00:00 committed by Linus Torvalds
parent 13d2080db3
commit dbf520a9d7
4 changed files with 12 additions and 14 deletions

View file

@ -51,7 +51,7 @@ struct task_struct;
extern void debug_show_all_locks(void);
extern void debug_show_held_locks(struct task_struct *task);
extern void debug_check_no_locks_freed(const void *from, unsigned long len);
extern void debug_check_no_locks_held(void);
extern void debug_check_no_locks_held(struct task_struct *task);
#else
static inline void debug_show_all_locks(void)
{
@ -67,7 +67,7 @@ debug_check_no_locks_freed(const void *from, unsigned long len)
}
static inline void
debug_check_no_locks_held(void)
debug_check_no_locks_held(struct task_struct *task)
{
}
#endif