[LTP] [PATCH v3] syscalls/ioctl_loop05: Use correct blockdev to get logical_block_size
Yang Xu
xuyang_jy_0410@163.com
Thu Jun 25 19:10:26 CEST 2020
Hi Cyril
Sorry for late reply.
> Hi!
>> +static void find_backing_bdpath(char *buf)
>> +{
>> + const char *const df_cmd[] = {"df", "-T", ".", NULL};
>> + char line[PATH_MAX];
>> + FILE *file;
>> +
>> + SAFE_CMD(df_cmd, "1.txt", NULL);
>> + file = SAFE_FOPEN("1.txt", "r");
>> +
>> + while (fgets(line, sizeof(line), file) != NULL) {
>> + sscanf(line, "%s", buf);
>> + if (strstr(buf, "/dev/") != NULL)
>> + break;
>> + }
>> + SAFE_FCLOSE(file);
>> +}
>
> I do not like that we are calling df for something like this.
>
> Looking at what that command does it's not that complex. It does
> statfs() to get minor and major number, then scans /proc/self/mountinfo
> for these, since these are on third column and then just prints whatever
> it's in the 10th column. This isn't more complex that what we have here
> and avoids needs to execute binaries and parse the output.
>
I look statfs manpage, its buf doesn't have dev_t type member, I think
it maybe stat function. But stat function has problem when filsystem
uses virtual block(such as btrfs,fuse, then major numer is 0).
I try to parse /proc/self/mountinfo(this format is not changed over
10years), as below:
diff --git a/testcases/kernel/syscalls/ioctl/ioctl_loop05.c
b/testcases/kernel/syscalls/ioctl/ioctl_loop05.c
index a96997823..d6db9cc83 100644
--- a/testcases/kernel/syscalls/ioctl/ioctl_loop05.c
+++ b/testcases/kernel/syscalls/ioctl/ioctl_loop05.c
@@ -28,12 +28,13 @@
#include <sys/mount.h>
#include "lapi/loop.h"
#include "tst_test.h"
+#include "tst_safe_stdio.h"
#define DIO_MESSAGE "In dio mode"
#define NON_DIO_MESSAGE "In non dio mode"
static char dev_path[1024], sys_loop_diopath[1024];
-static int dev_num, dev_fd, attach_flag, logical_block_size;
+static int dev_num, dev_fd, block_devfd, attach_flag, logical_block_size;
static void check_dio_value(int flag)
{
@@ -94,11 +95,34 @@ static void verify_ioctl_loop(void)
tst_res(TFAIL | TTERRNO, "LOOP_SET_DIRECT_IO failed
expected EINVAL got");
}
-static void setup(void)
+static void find_backing_bdpath(char *buf, char *bd_path)
{
- int fd;
- struct stat buf;
+ char fmt1[1024];
+ char fmt2[1024];
+ char mnt_root[100];
+ char line[PATH_MAX];
+ FILE *file;
+
+ sprintf(fmt1, "%%*i %%*i %%*u:%%*u %%*s %s %%*s %%*s %%*s %%*s
%%s %%*s", buf);
+ sprintf(fmt2, "%%*i %%*i %%*u:%%*u %%*s %%s %%*s %%*s %%*s %%*s
%%s %%*s");
+ if (!FILE_LINES_SCANF("/proc/self/mountinfo", fmt1, bd_path)) {
+ tst_res(TINFO, "have %s mntpoint", buf);
+ return;
+ }
+ tst_res(TINFO, "Not have %s mntpoint, try /", buf);
+ file = SAFE_FOPEN("/proc/self/mountinfo", "r");
+ while (fgets(line, sizeof(line), file) != NULL) {
+ sscanf(line, fmt2, mnt_root, bd_path);
+ if(strcmp(mnt_root, "/"))
+ continue;
+ break;
+ }
+ SAFE_FCLOSE(file);
+}
+static void setup(void)
+{
+ char bd_path[100];
if (tst_fs_type(".") == TST_TMPFS_MAGIC)
tst_brk(TCONF, "tmpfd doesn't support O_DIRECT flag");
@@ -109,13 +133,6 @@ static void setup(void)
sprintf(sys_loop_diopath, "/sys/block/loop%d/loop/dio", dev_num);
tst_fill_file("test.img", 0, 1024, 1024);
- fd = SAFE_OPEN("test.img", O_RDONLY);
- SAFE_FSTAT(fd, &buf);
- SAFE_CLOSE(fd);
-
- logical_block_size = buf.st_blksize;
- tst_res(TINFO, "backing dev logical_block_size is %d",
logical_block_size);
-
tst_attach_device(dev_path, "test.img");
attach_flag = 1;
dev_fd = SAFE_OPEN(dev_path, O_RDWR);
@@ -130,13 +147,21 @@ static void setup(void)
* size of loop is bigger than the backing device's and the loop
* needn't transform transfer.
*/
- TST_RETRY_FUNC(ioctl(dev_fd, LOOP_SET_BLOCK_SIZE,
logical_block_size), TST_RETVAL_EQ0);
+ find_backing_bdpath("/tmp", bd_path);
+ block_devfd = SAFE_OPEN(bd_path, O_RDWR);
+ SAFE_IOCTL(block_devfd, BLKSSZGET, &logical_block_size);
+ tst_res(TINFO, "backing dev logical_block_size is %d",
logical_block_size);
+ SAFE_CLOSE(block_devfd);
+ if (logical_block_size > 512)
+ TST_RETRY_FUNC(ioctl(dev_fd, LOOP_SET_BLOCK_SIZE,
logical_block_size), TST_RETVAL_EQ0);
}
static void cleanup(void)
{
if (dev_fd > 0)
SAFE_CLOSE(dev_fd);
+ if (block_devfd > 0)
+ SAFE_CLOSE(block_devfd);
if (attach_flag)
tst_detach_device(dev_path);
}
> Also this function could be in a test library probably in tst_device.h.
>
>> static void setup(void)
>> {
>> - int fd;
>> - struct stat buf;
>> + char buf[100];
>>
>> if (tst_fs_type(".") == TST_TMPFS_MAGIC)
>> tst_brk(TCONF, "tmpfd doesn't support O_DIRECT flag");
>> @@ -109,13 +126,6 @@ static void setup(void)
>> sprintf(sys_loop_diopath, "/sys/block/loop%d/loop/dio", dev_num);
>> tst_fill_file("test.img", 0, 1024, 1024);
>>
>> - fd = SAFE_OPEN("test.img", O_RDONLY);
>> - SAFE_FSTAT(fd, &buf);
>> - SAFE_CLOSE(fd);
>> -
>> - logical_block_size = buf.st_blksize;
>> - tst_res(TINFO, "backing dev logical_block_size is %d", logical_block_size);
>> -
>> tst_attach_device(dev_path, "test.img");
>> attach_flag = 1;
>> dev_fd = SAFE_OPEN(dev_path, O_RDWR);
>> @@ -130,13 +140,23 @@ static void setup(void)
>> * size of loop is bigger than the backing device's and the loop
>> * needn't transform transfer.
>> */
>> - TST_RETRY_FUNC(ioctl(dev_fd, LOOP_SET_BLOCK_SIZE, logical_block_size), TST_RETVAL_EQ0);
>> + find_backing_bdpath(buf);
>> + block_devfd = SAFE_OPEN(buf, O_RDWR);
>> +
>> + SAFE_IOCTL(block_devfd, BLKSSZGET, &logical_block_size);
>> + tst_res(TINFO, "backing dev logical_block_size is %d", logical_block_size);
>> + SAFE_CLOSE(block_devfd);
>> +
>> + if (logical_block_size > 512)
>> + TST_RETRY_FUNC(ioctl(dev_fd, LOOP_SET_BLOCK_SIZE, logical_block_size), TST_RETVAL_EQ0);
>> }
>>
>> static void cleanup(void)
>> {
>> if (dev_fd > 0)
>> SAFE_CLOSE(dev_fd);
>> + if (block_devfd > 0)
>> + SAFE_CLOSE(block_devfd);
>> if (attach_flag)
>> tst_detach_device(dev_path);
>> }
>> @@ -150,5 +170,9 @@ static struct tst_test test = {
>> .needs_drivers = (const char *const []) {
>> "loop",
>> NULL
>> + },
>> + .needs_cmds = (const char *const []) {
>> + "df",
>> + NULL
>> }
>> };
>> --
>> 2.23.0
>>
>>
>>
>>
>> --
>> Mailing list info: https://lists.linux.it/listinfo/ltp
>
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