Hello,
I saw the following splat on a machine:
[ 8909.508078]
[ 8909.509620] =================================
[ 8909.513996] [ INFO: inconsistent lock state ]
[ 8909.518378] 4.9.26 #1 Tainted: G W
[ 8909.522929] ---------------------------------
[ 8909.527307] inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
[ 8909.533858] kswapd0/24 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 8909.538926] (&f->sem){+.+.?.}, at: [<803512f4>] jffs2_do_clear_inode+0x20/0x134
{RECLAIM_FS-ON-W} state was registered at:
[ 8909.550305] lockdep_trace_alloc+0xa4/0x128
[ 8909.554603] __kmalloc+0x3c/0x194
[ 8909.558030] jffs2_do_read_inode_internal+0x44/0x1914
[ 8909.563193] jffs2_do_read_inode+0xfc/0x208
[ 8909.567486] jffs2_iget+0x7c/0x350
[ 8909.570998] jffs2_do_fill_super+0xd8/0x250
[ 8909.575291] jffs2_fill_super+0xe0/0x138
[ 8909.579328] mount_mtd_aux+0x84/0xd4
[ 8909.583015] mount_mtd+0x104/0x144
[ 8909.586526] jffs2_mount+0x1c/0x28
[ 8909.590038] mount_fs+0x1c/0xb0
[ 8909.593290] vfs_kern_mount+0x5c/0x134
[ 8909.597149] do_mount+0x154/0xcc4
[ 8909.600575] SyS_mount+0x9c/0xc4
[ 8909.603915] ret_fast_syscall+0x0/0x1c
[ 8909.607769] irq event stamp: 155265
[ 8909.611287] hardirqs last enabled at (155265): [<8010d34c>] __irq_svc+0x8c/0xb0
[ 8909.618707] hardirqs last disabled at (155264): [<8010d320>] __irq_svc+0x60/0xb0
[ 8909.626133] softirqs last enabled at (155254): [<801271b8>] __do_softirq+0x220/0x2c4
[ 8909.633988] softirqs last disabled at (155213): [<801275d4>] irq_exit+0xc8/0xe4
[ 8909.641313]
[ 8909.641313] other info that might help us debug this:
[ 8909.647859] Possible unsafe locking scenario:
[ 8909.647859]
[ 8909.653798] CPU0
[ 8909.656259] ----
[ 8909.658718] lock(&f->sem);
[ 8909.661661] <Interrupt>
[ 8909.664297] lock(&f->sem);
[ 8909.667410]
[ 8909.667410] *** DEADLOCK ***
[ 8909.667410]
[ 8909.673357] 2 locks held by kswapd0/24:
[ 8909.677208] #0: (shrinker_rwsem){++++..}, at: [<801e9ab8>] shrink_slab.part.0.constprop.8+0x34/0x300
[ 8909.686630] #1: (&type->s_umount_key#30){.+.+..}, at: [<80227b3c>] trylock_super+0x1c/0x60
[ 8909.695212]
[ 8909.695212] stack backtrace:
[ 8909.699600] CPU: 0 PID: 24 Comm: kswapd0 Tainted: G W 4.9.26 #1
[ 8909.706667] Hardware name: Freescale i.MX6 Ultralite (Device Tree)
[ 8909.712863] Backtrace:
[ 8909.715366] [<8010c4cc>] (dump_backtrace) from [<8010c770>] (show_stack+0x18/0x1c)
[ 8909.722963] r7:00000080 r6:ffffffff r5:20010093 r4:00000000
[ 8909.728651] [<8010c758>] (show_stack) from [<803facdc>] (dump_stack+0xac/0xe0)
[ 8909.735906] [<803fac30>] (dump_stack) from [<8016bce8>] (print_usage_bug+0x1e4/0x2d8)
[ 8909.743764] r10:00000002 r9:80a76ba8 r8:8152cf08 r7:00000008 r6:0000000a r5:80eae86c
[ 8909.751613] r4:8e9ba4c0 r3:00000002
[ 8909.755219] [<8016bb04>] (print_usage_bug) from [<8016c364>] (mark_lock+0x588/0x6d0)
[ 8909.762990] r9:80d1fce0 r8:8016b168 r7:8e9ba4c0 r6:00000008 r5:8e9ba9c0 r4:0000000a
[ 8909.770763] [<8016bddc>] (mark_lock) from [<8016cd88>] (__lock_acquire+0x2f0/0x186c)
[ 8909.778534] r10:00000002 r9:80d1fce0 r8:00000002 r7:814debd4 r6:8e9ba4c0 r5:8e9ba9c0
[ 8909.786383] r4:000002d9 r3:00000004
[ 8909.789988] [<8016ca98>] (__lock_acquire) from [<8016e6c0>] (lock_acquire+0x74/0x94)
[ 8909.797761] r10:00000003 r9:00000006 r8:8e9ba4c0 r7:00000001 r6:00000001 r5:60010013
[ 8909.805608] r4:00000000
[ 8909.808177] [<8016e64c>] (lock_acquire) from [<80864a64>] (mutex_lock_nested+0x58/0x474)
[ 8909.816292] r7:814debd4 r6:803512f4 r5:00000000 r4:8e73c9e0
[ 8909.821983] [<80864a0c>] (mutex_lock_nested) from [<803512f4>] (jffs2_do_clear_inode+0x20/0x134)
[ 8909.830796] r10:00000003 r9:00000006 r8:8dcb700c r7:8dcb7000 r6:8dc1c800 r5:8e73c9e0
[ 8909.838643] r4:8e73ca40
[ 8909.841207] [<803512d4>] (jffs2_do_clear_inode) from [<803569b8>] (jffs2_evict_inode+0x34/0x38)
[ 8909.849930] r7:8dcb7000 r6:80911564 r5:8dc1c800 r4:8e73ca40
[ 8909.855622] [<80356984>] (jffs2_evict_inode) from [<80243090>] (evict+0xa4/0x164)
[ 8909.863125] r5:8e73cb3c r4:8e73ca40
[ 8909.866731] [<80242fec>] (evict) from [<8024318c>] (dispose_list+0x3c/0x4c)
[ 8909.873717] r7:8dcb7000 r6:00000009 r5:00000001 r4:8ea5fd30
[ 8909.879408] [<80243150>] (dispose_list) from [<80244388>] (prune_icache_sb+0x48/0x58)
[ 8909.887258] r5:00000001 r4:8ea5fd30
[ 8909.890868] [<80244340>] (prune_icache_sb) from [<80227cd0>] (super_cache_scan+0x150/0x1a0)
[ 8909.899240] r5:8dcb74ec r4:8ea5fdc0
[ 8909.902848] [<80227b80>] (super_cache_scan) from [<801e9cb8>] (shrink_slab.part.0.constprop.8+0x234/0x300)
[ 8909.912531] r10:00000000 r9:00000000 r8:80c53638 r7:8dcb74ec r6:00000400 r5:0000000d
[ 8909.920378] r4:0000000d
[ 8909.922942] [<801e9a84>] (shrink_slab.part.0.constprop.8) from [<801ecb2c>] (shrink_node+0x73c/0x8bc)
[ 8909.932188] r10:80d53ba0 r9:8ea5fed0 r8:00000000 r7:00000007 r6:0000011b r5:8ea5fe44
[ 8909.940034] r4:00000004
[ 8909.942595] [<801ec3f0>] (shrink_node) from [<801ed55c>] (kswapd+0x354/0x648)
[ 8909.949758] r10:8ea5e000 r9:80d53400 r8:00000000 r7:ffffffff r6:80d530c0 r5:00000000
[ 8909.957605] r4:80d53400
[ 8909.960169] [<801ed208>] (kswapd) from [<801437ac>] (kthread+0xf8/0x114)
[ 8909.966899] r10:00000000 r9:00000000 r8:00000000 r7:801ed208 r6:80d53400 r5:8ea4e340
[ 8909.974746] r4:00000000
[ 8909.977310] [<801436b4>] (kthread) from [<80107f30>] (ret_from_fork+0x14/0x24)
[ 8909.984557] r7:00000000 r6:00000000 r5:801436b4 r4:8ea4e340
I'm not fluent enough in lockdep to immediatly understand the problem,
so I wonder if this is already known and maybe even worked at before
spending time here.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |