SLES12 SP3 System crash in fscache_put_operation()

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Environment

SUSE Linux Enterprise Server 12 Service Pack 3 (SLES 12 SP3)

with Kernel 4.4.138-94.39-default

Situation

A System which mounts NFS filesystems with the "-o fsc" option may suffer a system panic if lots of files are stored in memory. The stack trace of the failing task can look like:

PID: 127376  TASK: ffff88804ffdd0c0  CPU: 120  COMMAND: "kworker/u771:2"
 #0 [ffff8893fcc47b80] machine_kexec at ffffffff8105990c
 #1 [ffff8893fcc47bd0] __crash_kexec at ffffffff81117b8a
 #2 [ffff8893fcc47c90] crash_kexec at ffffffff81117c5c
 #3 [ffff8893fcc47ca0] oops_end at ffffffff8101a5f4
 #4 [ffff8893fcc47cc0] do_error_trap at ffffffff810181b0
 #5 [ffff8893fcc47d70] invalid_op at ffffffff8161ad58
    [exception RIP: fscache_put_operation+0x1ea]
    RIP: ffffffffa117ffca  RSP: ffff8893fcc47e20  RFLAGS: 00010286
    RAX: 0000000000000019  RBX: ffff88bf2301ce80  RCX: 0000000000000000
    RDX: 0000000000000001  RSI: 0000000000000246  RDI: 0000000000000246
    RBP: ffff88bf22f58280   R8: 0000000000000019   R9: ffff89003fdf1e31
    R10: 00000000001c51f8  R11: 0000000000000000  R12: ffff8880c7cbe400
    R13: ffff88bf20c20300  R14: 0000000000000000  R15: 0000000000006060
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
 #6 [ffff8893fcc47e38] process_one_work at ffffffff81098b44
 #7 [ffff8893fcc47e78] worker_thread at ffffffff81099726
 #8 [ffff8893fcc47ed0] kthread at ffffffff8109ec49
 #9 [ffff8893fcc47f50] ret_from_fork at ffffffff81618a05

Resolution

This problem has been reported to engineering. In case a crash happened in this area please open a service request (SR) with a request to a program temporary fix (PTF).

Additional Information

Disclaimer

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