[LTP] [PATCHv2] syscalls/quotactl04: add mkfs.ext4 package version check

[Yang Xu <xuyang2018.jy@cn.fujitsu.com>]

Hi Po-Hsu
> The project quota feature was added in e2fsprogs 1.43 [1]:
>    E2fsprogs 1.43 (May 17, 2016)
>      Add support for the ext4 metadata checksum, checksum seed, inline
>      data, encryption, project quota, and read-only features.
>
> The test should be skipped when running with older package, otherwise
> it will fail with:
>    Invalid filesystem option set: quota,project
>
> Use popen and fscanf to get mkfs.ext4 -V output for version
> comparison. This version checking by adding digits together does not
> work with alphabets in the number like rc1, but in that case the test
> will still be tested.
>
> It will now be skipped with (Tested with Ubuntu Xenial + 4.15 kernel):
>    quotactl04.c:118: TCONF: Test needs mkfs.ext4>= 1.43 for encrypt
>    option, test skipped
Commit message is also wrong. But I think maintainer will correct this 
and don't need to send a v3.
>
> [1] http://e2fsprogs.sourceforge.net/e2fsprogs-release.html#1.42.13
>
> Signed-off-by: Po-Hsu Lin<po-hsu.lin@canonical.com>
> Reviewed-by: Yang Xu<xuyang2018.jy@cn.fujitsu.com>
> ---
>   testcases/kernel/syscalls/quotactl/quotactl04.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
>
> diff --git a/testcases/kernel/syscalls/quotactl/quotactl04.c b/testcases/kernel/syscalls/quotactl/quotactl04.c
> index 73980d7e9..3cc2b974f 100644
> --- a/testcases/kernel/syscalls/quotactl/quotactl04.c
> +++ b/testcases/kernel/syscalls/quotactl/quotactl04.c
> @@ -19,6 +19,8 @@
>    * 7) quotactl(2) succeeds to get disk quota limit greater than or equal to
>    *    ID with Q_GETNEXTQUOTA flag for project.
>    * 8) quotactl(2) succeeds to turn off quota with Q_QUOTAOFF flag for project.
> + *
> + * Minimum e2fsprogs version required is 1.43.
>    */
>
>   #include<errno.h>
> @@ -28,6 +30,7 @@
>   #include<sys/stat.h>
>   #include "config.h"
>   #include "lapi/quotactl.h"
> +#include "tst_safe_stdio.h"
>   #include "tst_test.h"
>
>   #ifndef QFMT_VFS_V1
> @@ -102,9 +105,18 @@ static struct tcase {
>
>   static void setup(void)
>   {
> +	FILE *f;
>   	const char *const fs_opts[] = {"-I 256", "-O quota,project", NULL};
> +	int rc, major, minor, patch;
>
>   	test_id = geteuid();
> +	f = SAFE_POPEN("mkfs.ext4 -V 2>&1", "r");
> +	rc = fscanf(f, "mke2fs %d.%d.%d",&major,&minor,&patch);
> +	if (rc != 3)
> +		tst_res(TWARN, "Unable parse version number");
> +	else if (major * 10000 + minor * 100 + patch<  14300)
> +		tst_brk(TCONF, "Test needs mkfs.ext4>= 1.43 for quota,project option, test skipped");
> +	pclose(f);
>   	SAFE_MKFS(tst_device->dev, tst_device->fs_type, fs_opts, NULL);
>   	SAFE_MOUNT(tst_device->dev, MNTPOINT, tst_device->fs_type, 0, "quota");
>   	mount_flag = 1;