contrib/getdents-debug: implement getdents -loop

$ ./getdents -loop /mnt/synology/public/tmp/g1
unix.Getdents: n=4176; n=4176; n=4176; n=4176; n=4176; n=3192; n=0; err=<nil>; total 24072 bytes
unix.Getdents: n=4176; n=4176; n=4176; n=4176; n=4176; n=3192; n=0; err=<nil>; total 24072 bytes
unix.Getdents: n=4176; n=-1; err=no such file or directory; total 4176 bytes
This commit is contained in:
Jakob Unterwurzacher 2020-05-25 23:30:59 +02:00
parent 0d522e0d3b
commit b275c53fa7
1 changed files with 28 additions and 13 deletions

View File

@ -27,6 +27,11 @@ unix.Getdents fd3: n=4176, err=<nil>
unix.Getdents fd3: n=3192, err=<nil>
unix.Getdents fd3: n=0, err=<nil>
total 24072 bytes
Failure looks like this in strace:
[pid 189974] getdents64(6, 0xc000105808, 10000) = -1 ENOENT (No such file or directory)
*/
package main
@ -34,7 +39,6 @@ package main
import (
"flag"
"fmt"
"log"
"os"
"golang.org/x/sys/unix"
@ -46,30 +50,41 @@ const (
func main() {
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "Usage: %s PATH\n", myName)
fmt.Fprintf(os.Stderr, "Usage: %s [-loop] PATH\n", myName)
fmt.Fprintf(os.Stderr, "Run getdents(2) on PATH\n")
os.Exit(1)
}
loop := flag.Bool("loop", false, "Run in a loop")
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)
sum := 0
fd, err := unix.Open(path, unix.O_RDONLY, 0)
if err != nil {
fmt.Printf("unix.Open returned err=%v\n", err)
continue
}
fmt.Printf("unix.Getdents: ")
for {
n, err := unix.Getdents(fd, tmp)
fmt.Printf("n=%d; ", n)
if n <= 0 {
fmt.Printf("err=%v; total %d bytes\n", err, sum)
if err != nil {
os.Exit(1)
}
break
}
sum += n
}
unix.Close(fd)
if !*loop {
break
}
sum += n
}
}