[LTP] [PATCH v1] fspick01.c: Check mount point was really remounted read only

[Li Wang]

Hi Wei,

On Wed, Aug 20, 2025 at 8:26 AM Wei Gao via ltp <ltp@lists.linux.it> wrote:

> Fixes: #1171
> The fspick01 test does not test if FSCONFIG_CMD_RECONFIGURE really
> reconfigures the mount point, e.g. if the mount point was really
> remounted read only.
>
> Signed-off-by: Wei Gao <wegao@suse.com>
> ---
>  testcases/kernel/syscalls/fspick/fspick01.c | 43 ++++++++++++++++++++-
>  1 file changed, 42 insertions(+), 1 deletion(-)
>
> diff --git a/testcases/kernel/syscalls/fspick/fspick01.c
> b/testcases/kernel/syscalls/fspick/fspick01.c
> index d03cacd3d..c2ad369d4 100644
> --- a/testcases/kernel/syscalls/fspick/fspick01.c
> +++ b/testcases/kernel/syscalls/fspick/fspick01.c
> @@ -6,6 +6,7 @@
>   */
>  #include "tst_test.h"
>  #include "lapi/fsmount.h"
> +#include "tst_safe_stdio.h"
>
>  #define MNTPOINT               "mntpoint"
>  #define TCASE_ENTRY(_flags)    {.name = "Flag " #_flags, .flags = _flags}
> @@ -20,11 +21,38 @@ static struct tcase {
>         TCASE_ENTRY(FSPICK_EMPTY_PATH),
>  };
>
> +static int is_mounted_ro(const char *path)
>

Maybe we can consider refactoring this function as a more generic,
e.g. tst_mount_has_opt(const char *path, const char *opt) and move
it into tst_device.c file?

static int tst_mount_has_opt(const char *path, const char *opt)
{
    ...
}

int tst_is_mounted_ro(const char *path)
{
    return tst_mount_has_opt(path, "ro");
}

int tst_is_mounted_rw(const char *path)
{
    return tst_mount_has_opt(path, "rw");
}

People can call tst_is_mounted_ro(path) or tst_is_mounted_rw(path) directly.


> +{
> +       char line[PATH_MAX];
> +       FILE *file;
> +       int ret = 0;
> +
> +       file = SAFE_FOPEN("/proc/mounts", "r");
> +
>



> +       while (fgets(line, sizeof(line), file)) {
> +               char dev[PATH_MAX], mount_point[PATH_MAX],
> fstype[PATH_MAX], options[PATH_MAX];
> +
> +               if (sscanf(line, "%s %s %s %s", dev, mount_point, fstype,
> options) < 4)
> +                       continue;
> +
> +               if (strstr(mount_point, path) && (strstr(options, "ro,")))
> {
>

strstr(mount_point, path) may give false positives (e.g. /mnt will match
/mnt2).
Better to use strcmp() or prefix matching with / boundaries.

How about this:

while (fgets(line, sizeof(line), file)) {
        char mount_point[PATH_MAX], options[PATH_MAX];

        if (sscanf(line, "%*s %s %*s %s", mount_point, options) < 2)
                continue;

        if (strcmp(mount_point, path) != 0)
                continue;

        char *tok = strtok(options, ",");
        while (tok) {
                if (strcmp(tok, opt) == 0) {
                        ret = 1;
                        break;
                }
                tok = strtok(NULL, ",");
            }
        if (ret)
                break;
}


+                       ret = 1;
> +                       break;
> +               }
> +       }
> +
>



> +       SAFE_FCLOSE(file);
> +
> +       return ret;
> +}
> +
>  static void run(unsigned int n)
>  {
>         struct tcase *tc = &tcases[n];
>         int fspick_fd;
>
> +       TST_EXP_VAL(is_mounted_ro(MNTPOINT), 0);
> +
>         TEST(fspick_fd = fspick(AT_FDCWD, MNTPOINT, tc->flags));
>         if (fspick_fd == -1) {
>                 tst_res(TFAIL | TTERRNO, "fspick() failed");
> @@ -49,8 +77,21 @@ static void run(unsigned int n)
>                 goto out;
>         }
>
> -       tst_res(TPASS, "%s: fspick() passed", tc->name);
> +       TST_EXP_VAL(is_mounted_ro(MNTPOINT), 1);
>
> +       TEST(fsconfig(fspick_fd, FSCONFIG_SET_FLAG, "rw", NULL, 0));
> +       if (TST_RET == -1) {
> +               tst_res(TFAIL | TTERRNO, "fsconfig(FSCONFIG_SET_FLAG)
> failed");
> +               goto out;
> +       }
> +
> +       TEST(fsconfig(fspick_fd, FSCONFIG_CMD_RECONFIGURE, NULL, NULL, 0));
> +       if (TST_RET == -1) {
> +               tst_res(TFAIL | TTERRNO,
> "fsconfig(FSCONFIG_CMD_RECONFIGURE) failed");
> +               goto out;
> +       }
> +
> +       tst_res(TPASS, "%s: fspick() passed", tc->name);
>  out:
>         SAFE_CLOSE(fspick_fd);
>  }
> --
> 2.43.0
>
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
>
>

-- 
Regards,
Li Wang