Add contrib/getdents

Small tool to try to debug unix.Getdents problems on CIFS mounts
https://github.com/rfjakob/gocryptfs/issues/483
This commit is contained in:
Jakob Unterwurzacher 2020-05-24 22:54:21 +02:00
parent 1a91a11e00
commit c7a9425e1b

View File

@ -0,0 +1,75 @@
/*
Small tool to try to debug unix.Getdents problems on CIFS mounts
( https://github.com/rfjakob/gocryptfs/issues/483 )
Example output:
$ while sleep 1 ; do ./getdents /mnt/synology/public/tmp/g1 ; done
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=3192, err=<nil>
unix.Getdents fd3: n=0, err=<nil>
total 24072 bytes
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=-1, err=no such file or directory
total 16704 bytes
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=3192, err=<nil>
unix.Getdents fd3: n=0, err=<nil>
total 24072 bytes
*/
package main
import (
"flag"
"fmt"
"log"
"os"
"golang.org/x/sys/unix"
)
const (
myName = "getdents"
)
func main() {
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "Usage: %s PATH\n", myName)
fmt.Fprintf(os.Stderr, "Run getdents(2) on PATH\n")
os.Exit(1)
}
flag.Parse()
if flag.NArg() != 1 {
flag.Usage()
}
path := flag.Arg(0)
fd, err := unix.Open(path, unix.O_RDONLY, 0)
if err != nil {
log.Fatalf("unix.Open returned err=%v", err)
}
tmp := make([]byte, 10000)
sum := 0
for {
n, err := unix.Getdents(fd, tmp)
fmt.Printf("unix.Getdents fd%d: n=%d, err=%v\n", fd, n, err)
if n <= 0 {
fmt.Printf("total %d bytes\n", sum)
break
}
sum += n
}
}