Issue

• The server with VxFS filesystem may crash at iput+0x2d called from vx_softcnt_flush with the following or similar call trace:

PID: 26504  TASK: ffff810b7b8c67a0  CPU: 2   COMMAND: "vx_worklist_thr"
 #0 [ffff810b71fcba80] crash_kexec at ffffffff800aaa93
 #1 [ffff810b71fcbb40] __die at ffffffff8006520f
 #2 [ffff810b71fcbb80] do_page_fault at ffffffff80066e1c
 #3 [ffff810b71fcbc70] error_exit at ffffffff8005dde9
    [exception RIP: iput+45]
    RIP: ffffffff8002a88f  RSP: ffff810b71fcbd20  RFLAGS: 00010206
    RAX: 0000000000001000  RBX: ffff8105bc0f0f20  RCX: 0000000000000000
    RDX: 0000000000000000  RSI: 0000000000000286  RDI: ffff8105bc0f0f20
    RBP: ffff8105bc0f0f20   R8: ffff810b71fcbe3c   R9: 0000000000000000
    R10: ffff8105821cb730  R11: 0000000000000050  R12: ffff8105bc0f08b8
    R13: ffff810b71fcbdb8  R14: ffff8105bc0f0f20  R15: 0000000000000258
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #4 [ffff810b71fcbd28] vx_softcnt_flush at ffffffff884d4cc4
 #5 [ffff810b71fcbd58] vx_ireuse_clean at ffffffff8849cb70
 #6 [ffff810b71fcbd88] vx_ilist_chunkclean at ffffffff8849d660
 #7 [ffff810b71fcbdf8] vx_inode_free_list at ffffffff8849eedf
 #8 [ffff810b71fcbe38] vx_ifree_scan_list at ffffffff8848e23e
 #9 [ffff810b71fcbe48] vx_workitem_process at ffffffff8848d461
#10 [ffff810b71fcbe58] vx_worklist_process at ffffffff8848d656
#11 [ffff810b71fcbed8] vx_worklist_thread at ffffffff884904bd
#12 [ffff810b71fcbee8] vx_kthread_init at ffffffff884d2d19
#13 [ffff810b71fcbf48] kernel_thread at ffffffff8005dfb1

• Also the server may crash at vx_softcnt_flush+0x5f with the following or similar call trace:

PID: 6458   TASK: ffff81062303c040  CPU: 8   COMMAND: "vx_worklist_thr"
 #0 [ffff810621153a50] crash_kexec at ffffffff800af85a
 #1 [ffff810621153b10] __die at ffffffff80065117
 #2 [ffff810621153b50] do_page_fault at ffffffff8006748d
 #3 [ffff810621153c40] error_exit at ffffffff8005dde9
 #4 [ffff810621153cf8] vx_softcnt_flush at ffffffff885d85ae [vxfs]
 #5 [ffff810621153d28] vx_ireuse_clean at ffffffff8859f619 [vxfs]
 #6 [ffff810621153d58] vx_ilist_chunkflush at ffffffff8859faf3 [vxfs]
 #7 [ffff810621153d98] vx_ilist_chunkclean at ffffffff8859fea1 [vxfs]
 #8 [ffff810621153df8] vx_inode_free_list at ffffffff885a175a [vxfs]
 #9 [ffff810621153e38] vx_ifree_scan_list at ffffffff88590851 [vxfs]
#10 [ffff810621153e48] vx_workitem_process at ffffffff8858f9c5 [vxfs]
#11 [ffff810621153e58] vx_worklist_process at ffffffff8858fbba [vxfs]
#12 [ffff810621153ed8] vx_worklist_thread at ffffffff88592c9c [vxfs]
#13 [ffff810621153ee8] vx_kthread_init at ffffffff885d6ac4 [vxfs]
#14 [ffff810621153f48] kernel_thread at ffffffff8005dfb1