fusefrontend: sharedstorage: lock truncate agains concurrent accessLockSharedStorage_rebase1

Prevent reads and writes concurrent with the truncate operation. It's
racy on tmpfs and ext4 ( https://lore.kernel.org/all/18e9fa0f-ec31-9107-459c-ae1694503f87@gmail.com/t/ )
as evident by TestOpenTruncate test failures:

  === RUN   TestOpenTruncate
      cluster_test.go:209: POSIX compliance issue: non-exlusive create failed with err=file exists
  doRead 16384215: corrupt block #0: cipher: message authentication failed
  ino16384215 fh8: RMW read failed: errno=5
      cluster_test.go:214: iteration 1: WriteAt: write /tmp/gocryptfs-test-parent-1026/1358464214/TestOpenTruncate.1788296708.mnt2/foo: input/output error
  --- FAIL: TestOpenTruncate (0.06s)
  FAIL
  exit status 1
  FAIL	github.com/rfjakob/gocryptfs/v2/tests/cluster	7.880s

Relates-to: https://github.com/rfjakob/gocryptfs/issues/56

1 files changed, 9 insertions, 11 deletions

diff --git a/go.sum b/go.sum
index 37b5355..e6c11f8 100644
--- a/go.sum
+++ b/go.sum
@@ -2,14 +2,13 @@ github.com/aperturerobotics/jacobsa-crypto v1.0.2 h1:tNvVy1rev9FagnOyBmTcI6d23Ff
 github.com/aperturerobotics/jacobsa-crypto v1.0.2/go.mod h1:buWU1iY+FjIcfpb1aYfFJZfl07WlS7O30lTyC2iwjv8=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/hanwen/go-fuse/v2 v2.5.0 h1:JSJcwHQ1V9EGRy6QsosoLDMX6HaLdzyLOJpKdPqDt9k=
-github.com/hanwen/go-fuse/v2 v2.5.0/go.mod h1:xKwi1cF7nXAOBCXujD5ie0ZKsxc8GGSA1rlMJc+8IJs=
+github.com/hanwen/go-fuse/v2 v2.7.2 h1:SbJP1sUP+n1UF8NXBA14BuojmTez+mDgOk0bC057HQw=
+github.com/hanwen/go-fuse/v2 v2.7.2/go.mod h1:ugNaD/iv5JYyS1Rcvi57Wz7/vrLQJo10mmketmoef48=
 github.com/jacobsa/oglematchers v0.0.0-20150720000706-141901ea67cd h1:9GCSedGjMcLZCrusBZuo4tyKLpKUPenUUqi34AkuFmA=
 github.com/jacobsa/oglemock v0.0.0-20150831005832-e94d794d06ff h1:2xRHTvkpJ5zJmglXLRqHiZQNjUoOkhUyhTAhEQvPAWw=
 github.com/jacobsa/ogletest v0.0.0-20170503003838-80d50a735a11 h1:BMb8s3ENQLt5ulwVIHVDWFHp8eIXmbfSExkvdn9qMXI=
 github.com/jacobsa/reqtrace v0.0.0-20150505043853-245c9e0234cb h1:uSWBjJdMf47kQlXMwWEfmc864bA1wAC+Kl3ApryuG9Y=
 github.com/kylelemons/godebug v0.0.0-20170820004349-d65d576e9348 h1:MtvEpTB6LX3vkb4ax0b5D2DHbNAUsen0Gx5wZoq3lV4=
-github.com/kylelemons/godebug v0.0.0-20170820004349-d65d576e9348/go.mod h1:B69LEHPfb2qLo0BaaOLcbitczOKLWTsrBG9LczfCD4k=
 github.com/moby/sys/mountinfo v0.6.2 h1:BzJjoreD5BMFNmD9Rus6gdd1pLuecOFPt8wC+Vygl78=
 github.com/moby/sys/mountinfo v0.6.2/go.mod h1:IJb6JQeOklcdMU9F5xQ8ZALD+CUr5VlGpwtX+VE0rpI=
 github.com/pkg/xattr v0.4.9 h1:5883YPCtkSd8LFbs13nXplj9g9tlrwoJRjgpgMu1/fE=
@@ -25,16 +24,15 @@ github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-golang.org/x/crypto v0.18.0 h1:PGVlW0xEltQnzFZ55hkuX5+KLyrMYhHld1YHO4AKcdc=
-golang.org/x/crypto v0.18.0/go.mod h1:R0j02AL6hcrfOiy9T4ZYp/rcWeMxM3L6QYxlOuEG1mg=
-golang.org/x/net v0.15.0 h1:ugBLEUaxABaB5AJqW9enI0ACdci2RUd4eP51NTBvuJ8=
-golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=
+golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
+golang.org/x/net v0.21.0 h1:AQyQV4dYCvJ7vGmJyKki9+PBdyvhkSd8EIx/qb0AYv4=
 golang.org/x/sys v0.0.0-20220408201424-a24fb2fb8a0f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.16.0 h1:xWw16ngr6ZMtmxDyKyIgsE93KNKz5HKmMa3b8ALHidU=
-golang.org/x/sys v0.16.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/term v0.16.0 h1:m+B6fahuftsE9qjo0VWp2FW0mB3MTJvR0BaMQrq0pmE=
-golang.org/x/term v0.16.0/go.mod h1:yn7UURbUtPyrVJPGPq404EukNFxcm/foM+bV/bfcDsY=
+golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
+golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/term v0.27.0 h1:WP60Sv1nlK1T6SupCHbXzSaN0b9wUmsPoRS9b61A23Q=
+golang.org/x/term v0.27.0/go.mod h1:iMsnZpn0cago0GOrHO2+Y7u7JPn5AylBrcoWkElMTSM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=