On Tue, Jan 29, 2019 at 04:09:16PM +0800, Zorro Lang wrote:
> copyrange_f and splice_f functions use a while loop to read a file,
> it's fine if there's only one fsstress process(and its children),
> but if some third part testing processes remove the file in the
> middle phase of copyrange_f running, copyrange_f maybe always return
> 0, and the while loop can't be end. As below:
>
> root 47184 xxxxxx S+ ./fsstress -R -d /mnt/scratch -n 10000 -p 20 -v
> root 47187 xxxxxx R+ ./fsstress -d /mnt/scratch -n 10000 -p 20 -v
> root 47199 xxxxxx R+ ./fsstress -d /mnt/scratch -n 10000 -p 20 -v
> root 47314 xxxxxx S+ grep --color=auto fsstress
> ...
> ...
> copy_file_range(3, [372258], 4, [2658770], 71179, 0) = 0
> copy_file_range(3, [372258], 4, [2658770], 71179, 0) = 0
> copy_file_range(3, [372258], 4, [2658770], 71179, 0) = 0
> copy_file_range(3, [372258], 4, [2658770], 71179, 0) = 0
> ...
> ...
> lr-x------. 1 root root 64 Jan 28 11:34 /proc/47187/fd/3 -> '/mnt/scratch/p2/f2 (deleted)'
>
> Signed-off-by: Zorro Lang <zlang@xxxxxxxxxx>
> ---
> ltp/fsstress.c | 20 +++++++++++++++++++-
> 1 file changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/ltp/fsstress.c b/ltp/fsstress.c
> index c04feb78..68e40ee6 100644
> --- a/ltp/fsstress.c
> +++ b/ltp/fsstress.c
> @@ -2363,8 +2363,9 @@ copyrange_f(
> int v2;
> int fd1;
> int fd2;
> - size_t ret;
> + size_t ret = 0;
> int e;
> + int limit;
>
> /* Load paths */
> init_pathname(&fpath1);
> @@ -2446,6 +2447,7 @@ copyrange_f(
> off2 %= maxfsize;
> } while (stat1.st_ino == stat2.st_ino && llabs(off2 - off1) < len);
>
> + limit = 300;
> while (len > 0) {
> ret = syscall(__NR_copy_file_range, fd1, &off1, fd2, &off2,
> len, 0);
> @@ -2456,6 +2458,15 @@ copyrange_f(
> break;
> else if (ret > 0)
> len -= ret;
> + else {
> + /*
> + * if copy_file_range always get 0 byte, break from the
> + * infinite loop running
> + */
> + limit--;
> + if (limit <= 0)
> + break;
> + }
I think we could just break the while loop if ret == 0, no need to retry
300 times.
> }
> e = ret < 0 ? errno : 0;
> if (v1 || v2) {
> @@ -2790,6 +2801,7 @@ splice_f(int opno, long r)
> size_t bytes;
> int e;
> int filedes[2];
> + int limit;
>
> /* Load paths */
> init_pathname(&fpath1);
> @@ -2886,6 +2898,7 @@ splice_f(int opno, long r)
>
> bytes = 0;
> total = 0;
> + limit = 300;
> while (len > 0) {
> /* move to pipe buffer */
> ret1 = splice(fd1, &off1, filedes[1], NULL, len, 0);
> @@ -2907,6 +2920,11 @@ splice_f(int opno, long r)
>
> len -= ret1;
> total += ret1;
> + if (ret1 == 0) {
> + limit--;
> + if (limit <= 0)
> + break;
> + }
Same here, just check ret1 after the 'read' splice and break the loop if
ret1 == 0.
Thanks,
Eryu
> }
>
> if (ret1 < 0 || ret2 < 0)
> --
> 2.17.2
>
