improve readlink handling

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

.github/workflows/development.yml

@@ -12,7 +12,7 @@ jobs:
     strategy:
       matrix:
         go: [1.17]
-        os: [ubuntu-latest, macos-latest]
+        os: [ubuntu-18.04, macos-10.15]
         upload-coverage: [true]
         include:
           - go: 1.17
@@ -215,7 +215,7 @@ jobs:
 
   test-goarch-386:
     name: Run test cases on 32-bit arch
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
 
     steps:
       - uses: actions/checkout@v3
@@ -242,7 +242,7 @@ jobs:
 
   test-postgresql-mysql-crdb:
     name: Test with PgSQL/MySQL/Cockroach
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
 
     services:
       postgres:

.github/workflows/release.yml

@@ -10,7 +10,7 @@ env:
 jobs:
   prepare-sources-with-deps:
     name: Prepare sources with deps
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v3
       - name: Set up Go

cmd/revertprovider.go

@@ -58,7 +58,6 @@ Please take a look at the usage below to customize the options.`,
 func init() {
 	addConfigFlags(revertProviderCmd)
 	revertProviderCmd.Flags().IntVar(&revertProviderTargetVersion, "to-version", 10, `10 means the version supported in v2.1.x`)
-	revertProviderCmd.MarkFlagRequired("to-version") //nolint:errcheck
 
 	rootCmd.AddCommand(revertProviderCmd)
 }

docs/sftpfs.md

@@ -28,7 +28,7 @@ The password and the private key are stored as ciphertext according to your [KMS
 
 SHA256 fingerprints for remote server host keys are optional but highly recommended: if you provide one or more fingerprints the server host key will be verified against them and the connection will be denied if none of the fingerprints provided match that for the server host key.
 
-Specifying a prefix you can restrict all operations to a given path within the remote SFTP server.
+Specifying a prefix you can restrict all operations to a given path within the remote SFTP server. If you set a prefix make sure it is not inside a symlinked directory or it is a symlink itself.
 
 Buffering can be enabled by setting a buffer size (in MB) greater than 0. By enabling buffering, the reads and writes, from/to the remote SFTP server, are split in multiple concurrent requests and this allows data to be transferred at a faster rate, over high latency networks, by overlapping round-trip times. With buffering enabled, resuming uploads and trucate are not supported and a file cannot be opened for both reading and writing at the same time. 0 means disabled.
 

go.mod

@@ -7,11 +7,11 @@ require (
 	github.com/Azure/azure-storage-blob-go v0.14.0
 	github.com/GehirnInc/crypt v0.0.0-20200316065508-bb7000b8a962
 	github.com/alexedwards/argon2id v0.0.0-20211130144151-3585854a6387
-	github.com/aws/aws-sdk-go v1.43.40
+	github.com/aws/aws-sdk-go v1.44.1
 	github.com/cockroachdb/cockroach-go/v2 v2.2.8
 	github.com/eikenb/pipeat v0.0.0-20210730190139-06b3e6902001
-	github.com/fclairamb/ftpserverlib v0.17.1-0.20220317111420-26600d07c50e
-	github.com/fclairamb/go-log v0.2.0
+	github.com/fclairamb/ftpserverlib v0.18.0
+	github.com/fclairamb/go-log v0.3.0
 	github.com/go-chi/chi/v5 v5.0.8-0.20220103230436-7dbe9a0bd10f
 	github.com/go-chi/jwtauth/v5 v5.0.2
 	github.com/go-chi/render v1.0.1
@@ -24,7 +24,7 @@ require (
 	github.com/hashicorp/go-plugin v1.4.3
 	github.com/hashicorp/go-retryablehttp v0.7.1
 	github.com/jlaffaye/ftp v0.0.0-20201112195030-9aae4d151126
-	github.com/klauspost/compress v1.15.1
+	github.com/klauspost/compress v1.15.2
 	github.com/lestrrat-go/jwx v1.2.23
 	github.com/lib/pq v1.10.5
 	github.com/lithammer/shortuuid/v3 v3.0.7
@@ -54,33 +54,33 @@ require (
 	gocloud.dev v0.25.0
 	golang.org/x/crypto v0.0.0-20220411220226-7b82a4e95df4
 	golang.org/x/net v0.0.0-20220412020605-290c469a71a5
-	golang.org/x/sys v0.0.0-20220412211240-33da011f77ad
+	golang.org/x/sys v0.0.0-20220422013727-9388b58f7150
 	golang.org/x/time v0.0.0-20220411224347-583f2d630306
-	google.golang.org/api v0.74.0
+	google.golang.org/api v0.76.0
 	gopkg.in/natefinch/lumberjack.v2 v2.0.0
 )
 
 require (
-	cloud.google.com/go v0.100.2 // indirect
-	cloud.google.com/go/compute v1.6.0 // indirect
+	cloud.google.com/go v0.101.0 // indirect
+	cloud.google.com/go/compute v1.6.1 // indirect
 	cloud.google.com/go/iam v0.3.0 // indirect
 	github.com/Azure/azure-pipeline-go v0.2.3 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/boombuler/barcode v1.0.1 // indirect
 	github.com/cenkalti/backoff v2.2.1+incompatible // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/coreos/go-systemd/v22 v22.3.3-0.20220203105225-a9a7ef127534 // indirect
-	github.com/cpuguy83/go-md2man/v2 v2.0.1 // indirect
+	github.com/cpuguy83/go-md2man/v2 v2.0.2 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
 	github.com/fatih/color v1.13.0 // indirect
-	github.com/fsnotify/fsnotify v1.5.1 // indirect
+	github.com/fsnotify/fsnotify v1.5.4 // indirect
 	github.com/go-ole/go-ole v1.2.6 // indirect
 	github.com/go-test/deep v1.0.8 // indirect
-	github.com/goccy/go-json v0.9.6 // indirect
+	github.com/goccy/go-json v0.9.7 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
-	github.com/google/go-cmp v0.5.7 // indirect
+	github.com/google/go-cmp v0.5.8 // indirect
 	github.com/googleapis/gax-go/v2 v2.3.0 // indirect
 	github.com/googleapis/go-type-adapters v1.0.0 // indirect
 	github.com/hashicorp/go-cleanhttp v0.5.2 // indirect
@@ -104,15 +104,15 @@ require (
 	github.com/miekg/dns v1.1.48 // indirect
 	github.com/minio/sha256-simd v1.0.0 // indirect
 	github.com/mitchellh/go-testing-interface v1.14.1 // indirect
-	github.com/mitchellh/mapstructure v1.4.3 // indirect
+	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/oklog/run v1.1.0 // indirect
-	github.com/pelletier/go-toml v1.9.4 // indirect
+	github.com/pelletier/go-toml v1.9.5 // indirect
 	github.com/pelletier/go-toml/v2 v2.0.0-beta.8 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/power-devops/perfstat v0.0.0-20220216144756-c35f1ee13d7c // indirect
 	github.com/prometheus/client_model v0.2.0 // indirect
-	github.com/prometheus/common v0.33.0 // indirect
+	github.com/prometheus/common v0.34.0 // indirect
 	github.com/prometheus/procfs v0.7.3 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/spf13/cast v1.4.1 // indirect
@@ -130,8 +130,8 @@ require (
 	golang.org/x/tools v0.1.10 // indirect
 	golang.org/x/xerrors v0.0.0-20220411194840-2f41105eb62f // indirect
 	google.golang.org/appengine v1.6.7 // indirect
-	google.golang.org/genproto v0.0.0-20220414192740-2d67ff6cf2b4 // indirect
-	google.golang.org/grpc v1.45.0 // indirect
+	google.golang.org/genproto v0.0.0-20220426171045-31bebdecfb46 // indirect
+	google.golang.org/grpc v1.46.0 // indirect
 	google.golang.org/protobuf v1.28.0 // indirect
 	gopkg.in/ini.v1 v1.66.4 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect