diff options
author | Paul Walmsley <paul@pwsan.com> | 2013-03-30 20:04:40 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-03-31 14:38:33 -0400 |
commit | dbf520a9d7d4d5ba28d2947be11e34099a5e3e20 (patch) | |
tree | 29e7a07a13a76a89b3c175c58592b2d3b176cfa5 /kernel | |
parent | 13d2080db3472b3399ba32e6026960de5d32a344 (diff) |
Revert "lockdep: check that no locks held at freeze time"
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>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/exit.c | 2 | ||||
-rw-r--r-- | kernel/lockdep.c | 17 |
2 files changed, 10 insertions, 9 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 51e485ca9935..60bc027c61c3 100644 --- a/kernel/exit.c +++ b/kernel/exit.c | |||
@@ -835,7 +835,7 @@ void do_exit(long code) | |||
835 | /* | 835 | /* |
836 | * Make sure we are holding no locks: | 836 | * Make sure we are holding no locks: |
837 | */ | 837 | */ |
838 | debug_check_no_locks_held(); | 838 | debug_check_no_locks_held(tsk); |
839 | /* | 839 | /* |
840 | * We can do this unlocked here. The futex code uses this flag | 840 | * We can do this unlocked here. The futex code uses this flag |
841 | * just to verify whether the pi state cleanup has been done | 841 | * just to verify whether the pi state cleanup has been done |
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 259db207b5d9..8a0efac4f99d 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c | |||
@@ -4088,7 +4088,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len) | |||
4088 | } | 4088 | } |
4089 | EXPORT_SYMBOL_GPL(debug_check_no_locks_freed); | 4089 | EXPORT_SYMBOL_GPL(debug_check_no_locks_freed); |
4090 | 4090 | ||
4091 | static void print_held_locks_bug(void) | 4091 | static void print_held_locks_bug(struct task_struct *curr) |
4092 | { | 4092 | { |
4093 | if (!debug_locks_off()) | 4093 | if (!debug_locks_off()) |
4094 | return; | 4094 | return; |
@@ -4097,21 +4097,22 @@ static void print_held_locks_bug(void) | |||
4097 | 4097 | ||
4098 | printk("\n"); | 4098 | printk("\n"); |
4099 | printk("=====================================\n"); | 4099 | printk("=====================================\n"); |
4100 | printk("[ BUG: %s/%d still has locks held! ]\n", | 4100 | printk("[ BUG: lock held at task exit time! ]\n"); |
4101 | current->comm, task_pid_nr(current)); | ||
4102 | print_kernel_ident(); | 4101 | print_kernel_ident(); |
4103 | printk("-------------------------------------\n"); | 4102 | printk("-------------------------------------\n"); |
4104 | lockdep_print_held_locks(current); | 4103 | printk("%s/%d is exiting with locks still held!\n", |
4104 | curr->comm, task_pid_nr(curr)); | ||
4105 | lockdep_print_held_locks(curr); | ||
4106 | |||
4105 | printk("\nstack backtrace:\n"); | 4107 | printk("\nstack backtrace:\n"); |
4106 | dump_stack(); | 4108 | dump_stack(); |
4107 | } | 4109 | } |
4108 | 4110 | ||
4109 | void debug_check_no_locks_held(void) | 4111 | void debug_check_no_locks_held(struct task_struct *task) |
4110 | { | 4112 | { |
4111 | if (unlikely(current->lockdep_depth > 0)) | 4113 | if (unlikely(task->lockdep_depth > 0)) |
4112 | print_held_locks_bug(); | 4114 | print_held_locks_bug(task); |
4113 | } | 4115 | } |
4114 | EXPORT_SYMBOL_GPL(debug_check_no_locks_held); | ||
4115 | 4116 | ||
4116 | void debug_show_all_locks(void) | 4117 | void debug_show_all_locks(void) |
4117 | { | 4118 | { |