This reverts commit 6aa9707099c4b25700940eb3d016f16c4434360d.
Commit 6aa9707099c4 ("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:
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: 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>
76 lines
1.5 KiB
C
76 lines
1.5 KiB
C
#ifndef __LINUX_DEBUG_LOCKING_H
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#define __LINUX_DEBUG_LOCKING_H
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#include <linux/kernel.h>
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#include <linux/atomic.h>
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#include <linux/bug.h>
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struct task_struct;
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extern int debug_locks;
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extern int debug_locks_silent;
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static inline int __debug_locks_off(void)
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{
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return xchg(&debug_locks, 0);
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}
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/*
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* Generic 'turn off all lock debugging' function:
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*/
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extern int debug_locks_off(void);
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#define DEBUG_LOCKS_WARN_ON(c) \
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({ \
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int __ret = 0; \
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\
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if (!oops_in_progress && unlikely(c)) { \
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if (debug_locks_off() && !debug_locks_silent) \
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WARN_ON(1); \
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__ret = 1; \
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} \
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__ret; \
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})
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#ifdef CONFIG_SMP
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# define SMP_DEBUG_LOCKS_WARN_ON(c) DEBUG_LOCKS_WARN_ON(c)
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#else
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# define SMP_DEBUG_LOCKS_WARN_ON(c) do { } while (0)
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#endif
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#ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
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extern void locking_selftest(void);
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#else
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# define locking_selftest() do { } while (0)
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#endif
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struct task_struct;
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#ifdef CONFIG_LOCKDEP
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extern void debug_show_all_locks(void);
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extern void debug_show_held_locks(struct task_struct *task);
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extern void debug_check_no_locks_freed(const void *from, unsigned long len);
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extern void debug_check_no_locks_held(struct task_struct *task);
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#else
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static inline void debug_show_all_locks(void)
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{
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}
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static inline void debug_show_held_locks(struct task_struct *task)
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{
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}
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static inline void
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debug_check_no_locks_freed(const void *from, unsigned long len)
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{
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}
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static inline void
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debug_check_no_locks_held(struct task_struct *task)
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{
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}
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#endif
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#endif
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