nil pointer dereference in pathfs.go:506

[rfjakob]

I managed to reproduce the nil pointer dereference that I mentioned in #99 with latest master.

loopback example output:

/tmp$ ~/src/github.com/hanwen/go-fuse/example/loopback/loopback b a
Mounted!
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x38 pc=0x4ce100]

goroutine 6062 [running]:
github.com/hanwen/go-fuse/fuse/pathfs.(*pathInode).Rename(0xc82055a280, 0xc820199aa0, 0x4, 0x7fe4b9f8f688, 0xc82055a680, 0xc820199ab0, 0x4, 0xc8200e1820, 0x0)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/pathfs/pathfs.go:506 +0x310
github.com/hanwen/go-fuse/fuse/nodefs.(*rawBridge).Rename(0xc82000a810, 0xc8200e1808, 0xc820199aa0, 0x4, 0xc820199ab0, 0x4, 0x0)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/nodefs/fsops.go:314 +0x156
github.com/hanwen/go-fuse/fuse.doRename(0xc820088000, 0xc8200e1680)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/opcode.go:346 +0xb0
github.com/hanwen/go-fuse/fuse.(*Server).handleRequest(0xc820088000, 0xc8200e1680)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:358 +0x305
github.com/hanwen/go-fuse/fuse.(*Server).loop(0xc820088000, 0x52e401)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:337 +0xe2
created by github.com/hanwen/go-fuse/fuse.(*Server).readRequest
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:265 +0x60e

goroutine 1 [semacquire, 8 minutes]:
sync.runtime_Semacquire(0xc8200880e0)
    /usr/lib/golang/src/runtime/sema.go:43 +0x26
sync.(*WaitGroup).Wait(0xc8200880d4)
    /usr/lib/golang/src/sync/waitgroup.go:126 +0xb4
github.com/hanwen/go-fuse/fuse.(*Server).Serve(0xc820088000)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:307 +0x71
main.main()
    /home/jakob/src/github.com/hanwen/go-fuse/example/loopback/main.go:87 +0xfd6

goroutine 6041 [syscall]:
syscall.Syscall(0x0, 0x5, 0xc8204b6000, 0x11000, 0x4faf58, 0xc8204b4188, 0x22ffffffff)
    /usr/lib/golang/src/syscall/asm_linux_amd64.s:18 +0x5
syscall.read(0x5, 0xc8204b6000, 0x11000, 0x11000, 0x4fb67f, 0x0, 0x0)
    /usr/lib/golang/src/syscall/zsyscall_linux_amd64.go:783 +0x5f
syscall.Read(0x5, 0xc8204b6000, 0x11000, 0x11000, 0xc820199630, 0x0, 0x0)
    /usr/lib/golang/src/syscall/syscall_unix.go:160 +0x4d
github.com/hanwen/go-fuse/fuse.(*Server).readRequest.func1(0x0, 0x0)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:240 +0x64
github.com/hanwen/go-fuse/fuse.handleEINTR(0xc8203dbf08, 0x0, 0x0)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:216 +0x2b
github.com/hanwen/go-fuse/fuse.(*Server).readRequest(0xc820088000, 0xc8200e0d01, 0xc8200e0d80, 0x0)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:238 +0x1fa
github.com/hanwen/go-fuse/fuse.(*Server).loop(0xc820088000, 0x52e401)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:318 +0x7a
created by github.com/hanwen/go-fuse/fuse.(*Server).readRequest
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:265 +0x60e

goroutine 6053 [syscall]:
syscall.Syscall(0x0, 0x5, 0xc820520000, 0x11000, 0xc8203dfd38, 0xc82055d360, 0x52e400)
    /usr/lib/golang/src/syscall/asm_linux_amd64.s:18 +0x5
syscall.read(0x5, 0xc820520000, 0x11000, 0x11000, 0x4fb6a8, 0x0, 0x0)
    /usr/lib/golang/src/syscall/zsyscall_linux_amd64.go:783 +0x5f
syscall.Read(0x5, 0xc820520000, 0x11000, 0x11000, 0xc820088078, 0x0, 0x0)
    /usr/lib/golang/src/syscall/syscall_unix.go:160 +0x4d
github.com/hanwen/go-fuse/fuse.(*Server).readRequest.func1(0x0, 0x0)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:240 +0x64
github.com/hanwen/go-fuse/fuse.handleEINTR(0xc8203dff08, 0x0, 0x0)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:216 +0x2b
github.com/hanwen/go-fuse/fuse.(*Server).readRequest(0xc820088000, 0xc8200e0601, 0xc8200e06c0, 0x0)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:238 +0x1fa
github.com/hanwen/go-fuse/fuse.(*Server).loop(0xc820088000, 0x52e401)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:318 +0x7a
created by github.com/hanwen/go-fuse/fuse.(*Server).readRequest
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:265 +0x60e

goroutine 6025 [syscall]:
syscall.Syscall(0x0, 0x5, 0xc820462000, 0x11000, 0x2, 0xc820019110, 0x4b26cc)
    /usr/lib/golang/src/syscall/asm_linux_amd64.s:18 +0x5
syscall.read(0x5, 0xc820462000, 0x11000, 0x11000, 0x4b79b0, 0x0, 0x0)
    /usr/lib/golang/src/syscall/zsyscall_linux_amd64.go:783 +0x5f
syscall.Read(0x5, 0xc820462000, 0x11000, 0x11000, 0xc820088078, 0x0, 0x0)
    /usr/lib/golang/src/syscall/syscall_unix.go:160 +0x4d
github.com/hanwen/go-fuse/fuse.(*Server).readRequest.func1(0x0, 0x0)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:240 +0x64
github.com/hanwen/go-fuse/fuse.handleEINTR(0xc8204d3f08, 0x0, 0x0)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:216 +0x2b
github.com/hanwen/go-fuse/fuse.(*Server).readRequest(0xc820088000, 0xc8200e1d01, 0xc8200e1d40, 0x7fe400000000)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:238 +0x1fa
github.com/hanwen/go-fuse/fuse.(*Server).loop(0xc820088000, 0x52e401)
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:318 +0x7a
created by github.com/hanwen/go-fuse/fuse.(*Server).readRequest
    /home/jakob/src/github.com/hanwen/go-fuse/fuse/server.go:265 +0x60e

Test loop output:

( set -e; while true; do ~/src/fuse-xfstests/ltp/fsstress -p 1 -z -f rmdir=10 -f link=10 -f creat=10 -f mkdir=10 -f rename=30 -f stat=30 -f unlink=30 -f truncate=20 -m 8 -n 1000 -d /tmp/b; rm -R /tmp/b/*; sleep 1; done )
seed = 1457036032
seed = 1457193343
[400 lines more...]
seed = 1456698305
seed = 1456838337
rm: cannot remove ‘/tmp/b/*’: Transport endpoint is not connected

[rfjakob]

Fixed through #106 patchset.