Greetings, I got the below dmesg and the first bad commit is commit 2fc546abb938dac3bb72061b030d00e18896b336 Author: Tejun Heo Date: Tue Oct 22 07:03:56 2013 -0400 sysfs, kernfs: prepare read path for kernfs We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch rearranges read path so that the kernfs and sysfs parts are separate. * Regular file read path is refactored such that kernfs_seq_start/next/stop/show() handle all the boilerplate work including locking and updating event count for poll, while sysfs_kf_seq_show() deals with interaction with kobj show method. * Bin file read path is refactored such that kernfs_file_direct_read() handles all the boilerplate work including buffer management and locking, while sysfs_kf_bin_read() deals with interaction with bin_attribute read method. kernfs_file_read() is added. It invokes either the seq_file or direct read path depending on the file type. This will eventually allow using the same file_operations for both file types, which is necessary to separate out kernfs. While this patch changes the order of some operations, it shouldn't change any visible behavior. Signed-off-by: Tejun Heo +------------------------------------------------------------------------------------+--------------+--------------+ | | c60c2b7e4de8 | a3ccb6c1ef2f | +------------------------------------------------------------------------------------+--------------+--------------+ | good_boots | 511 | 60 | | has_kernel_error_warning | 673 | 38 | | BUG:kernel_test_hang | 556 | 10 | | INFO:task_blocked_for_more_than_seconds | 60 | 3 | | Kernel_panic-not_syncing:hung_task:blocked_tasks | 8 | 1 | | INFO:rcu_sched_detected_stalls_on_CPUs/tasks:(detected_by,t=jiffies,g=,c=,q=) | 8 | 1 | | INFO:NMI_handler(arch_trigger_all_cpu_backtrace_handler)took_too_long_to_run:msecs | 7 | 1 | | INFO:rcu_sched_self-detected_stall_on_CPU(t=jiffies_g=c=q=) | 4 | 5 | | Out_of_memory:Kill_process | 1 | 1 | | BUG:kernel_test_crashed | 55 | 3 | | general_protection_fault:SMP | 0 | 2 | | Kernel_panic-not_syncing:Attempted_to_kill_init_exitcode= | 0 | 9 | | WARNING:CPU:PID:at_drivers/pci/pci.c:pci_disable_device() | 0 | 1 | | WARNING:CPU:PID:at_lib/iomap.c:bad_io_access() | 0 | 5 | | is_trying_to_release_lock(of-mutex)at | 0 | 3 | | BUG:unable_to_handle_kernel_paging_request_at | 0 | 4 | | Oops:SMP | 0 | 7 | | WARNING:CPU:PID:at_drivers/ata/libata-eh.c:ata_eh_acquire() | 0 | 2 | | BUG:unable_to_handle_kernel_NULL_pointer_dereference_at | 0 | 2 | | BUG:unable_to_handle_kernel | 0 | 1 | | INFO:Stall_ended_before_state_dump_start | 0 | 1 | +------------------------------------------------------------------------------------+--------------+--------------+ [ 969.609526] [ BUG: bad unlock balance detected! ] [ 969.609529] 3.12.0-rc6-wl-01422-ga3ccb6c #384 Not tainted [ 969.609529] ------------------------------------- [ 969.609533] trinity-child1/3338 is trying to release lock (&of->mutex) at: [ 969.609542] [] mutex_unlock+0xe/0x10 [ 969.609543] but there are no more locks to release! [ 969.609544] [ 969.609544] other info that might help us debug this: [ 969.609545] 1 lock held by trinity-child1/3338: [ 969.609554] #0: (&p->lock){......}, at: [] seq_read+0x3c/0x34b [ 969.609554] [ 969.609554] stack backtrace: [ 969.609558] CPU: 1 PID: 3338 Comm: trinity-child1 Not tainted 3.12.0-rc6-wl-01422-ga3ccb6c #384 [ 969.609559] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 969.609563] 0000000000000000 ffff880019737d28 ffffffff81a3796d ffff88000fee2340 [ 969.609566] ffff880019737d50 ffffffff81119ef7 ffff88000fee2340 00000000ffffffff [ 969.609569] 0000000000000001 ffff880019737dc0 ffffffff8111bc30 0000000000000002 [ 969.609570] Call Trace: [ 969.609575] [] dump_stack+0x54/0x74 [ 969.609582] [] print_unlock_imbalance_bug+0xe5/0xee [ 969.609585] [] lock_release_non_nested+0x160/0x29b [ 969.609590] [] ? local_clock+0x41/0x5a [ 969.609594] [] ? mutex_unlock+0xe/0x10 [ 969.609597] [] ? mutex_unlock+0xe/0x10 [ 969.609600] [] lock_release+0x1f8/0x1fb [ 969.609604] [] __mutex_unlock_slowpath+0xef/0x153 [ 969.609607] [] mutex_unlock+0xe/0x10 [ 969.609610] [] kernfs_seq_stop+0x46/0x4c [ 969.609613] [] seq_read+0x21f/0x34b [ 969.609616] [] kernfs_file_read+0x3d/0x126 [ 969.609622] [] vfs_read+0xa1/0x151 [ 969.609625] [] SyS_read+0x4c/0x83 [ 969.609629] [] system_call_fastpath+0x16/0x1b git bisect start a3ccb6c1ef2ff3c5e681b0a36ba43feb8a3fb401 31d141e3a666269a3b6fcccddb0351caf7454240 -- git bisect good 1734bf83a82c52ed2658fe1f07742eac321813d3 # 21:29 296+ 50 Merge 'ath6kl/ath-next' into devel-hourly-2013102301 git bisect bad 75f1457ee73528f0e61c80fb1c7976535c64bfce # 22:16 24- 12 Merge 'wfg/virtio-net-sleeping-fix' into devel-hourly-2013102301 git bisect good 6b991c3763e15a0884095fc0c133980c5577e9c7 # 03:29 296+ 293 bnx2x: Prevent null pointer dereference on error flow git bisect good 95f4ad8f05ba7ecde62215163404d291dbc56d68 # 08:14 296+ 110 sysfs, kernfs: introduce kernfs_create_link() git bisect good dc2364837ae4416a7646494cb672175339388e60 # 11:51 296+ 142 Merge 'ath6kl/master' into devel-hourly-2013102301 git bisect bad acd8b9fc6b4242bdf72fd2b5a1ac5140f69f2932 # 12:25 3- 1 sysfs, kernfs: move internal decls to fs/kernfs/kernfs-internal.h git bisect bad 78676703fdf0f37ae33e890400a76fcd23b83739 # 13:56 18- 1 sysfs, kernfs: move sysfs_open_file to include/linux/kernfs.h git bisect bad 2fc546abb938dac3bb72061b030d00e18896b336 # 15:41 17- 1 sysfs, kernfs: prepare read path for kernfs git bisect good c16b43ff3bfac36ebb338091932969f9a82533f5 # 22:14 296+ 234 sysfs, kernfs: introduce kernfs_setattr() git bisect good c60c2b7e4de82fab809e29351f538d996c2dedc7 # 01:43 296+ 98 sysfs, kernfs: introduce kernfs_create_dir[_ns]() git bisect good c60c2b7e4de82fab809e29351f538d996c2dedc7 # 07:18 888+ 673 sysfs, kernfs: introduce kernfs_create_dir[_ns]() git bisect bad a3ccb6c1ef2ff3c5e681b0a36ba43feb8a3fb401 # 07:18 0- 38 Merge 'lunn/v3.12-rc5-rafael-next-dove-cpufreq' into devel-hourly-2013102301 git bisect good d255c59aab2a3fdf0bb8a5db75e50d9c926c3bb9 # 14:29 888+ 882 Merge tag 'for-linus-20131025' of git://git.infradead.org/linux-mtd git bisect good a0cf1abc25ac197dd97b857c0f6341066a8cb1cf # 05:24 888+ 774 Add linux-next specific files for 20130927 Thanks, Fengguang