[LTP] [PATCH 0/2] Fix acct failures on nearly full FS.

[LTP] [PATCH 0/2] Fix acct failures on nearly full FS.

[Cyril Hrubis]

Unfortunately it looks like BSD process accounting on Linux is bit of a
minefield, even when you enable the accounting and everything looks OK
kernel may still drop the data silently for a couple of reasons. You can
have a look at kernel/acct.c. This patch disables the test if there is
no enough disk space because in that case data are silently dropped.

If there is less than 4% of free space the accounting is silently
disabled from the start hence the test produces TCONF unless there is at
least 4.1% of free space now.

Cyril Hrubis (2):
  safe_macros: Add SAFE_STATFS()
  syscalls/acct02: Fix failures with nearly full FS

 include/tst_safe_macros.h               | 18 ++++++++++++++++++
 testcases/kernel/syscalls/acct/acct02.c | 12 ++++++++++++
 2 files changed, 30 insertions(+)

-- 
2.21.0

[LTP] [PATCH 1/2] safe_macros: Add SAFE_STATFS()

[Cyril Hrubis]

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
---
 include/tst_safe_macros.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/include/tst_safe_macros.h b/include/tst_safe_macros.h
index 53a888c80..80c4d9cb9 100644
--- a/include/tst_safe_macros.h
+++ b/include/tst_safe_macros.h
@@ -24,6 +24,7 @@
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
+#include <sys/vfs.h>
 #include <fcntl.h>
 #include <libgen.h>
 #include <signal.h>
@@ -340,6 +341,23 @@ static inline int safe_lstat(const char *file, const int lineno,
 #define SAFE_LSTAT(path, buf) \
 	safe_lstat(__FILE__, __LINE__, (path), (buf))
 
+static inline int safe_statfs(const char *file, const int lineno,
+                              const char *path, struct statfs *buf)
+{
+	int rval;
+
+	rval = statfs(path, buf);
+
+	if (rval == -1) {
+		tst_brk_(file, lineno, TBROK | TERRNO,
+		         "statfs(%s,%p) failed", path, buf);
+	}
+
+	return rval;
+}
+#define SAFE_STATFS(path, buf) \
+        safe_statfs(__FILE__, __LINE__, (path), (buf))
+
 static inline off_t safe_lseek(const char *file, const int lineno,
                                int fd, off_t offset, int whence)
 {
-- 
2.21.0

[LTP] [PATCH 2/2] syscalls/acct02: Fix failures with nearly full FS

[Cyril Hrubis]

While process accounting is running the kernel checks the percentage of
available space on disk. If the accounting is enabled and the free space
drops below 2% the accounting is disabled until we reach at least 4% of
free space. Which especially means that we have to have more than 4% of
free space when we start the accounting because we are starting in
disabled state. And when accounting is disabled the data are dropped
silently instead of being written to the file, which makes this test
fail because we end up with an empty file.

So this patch checks if there is at least 4.1% of free space before we
start the test and exit with TCONF otherwise.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
CC: Christian Amann <camann@suse.com>
---
 testcases/kernel/syscalls/acct/acct02.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/testcases/kernel/syscalls/acct/acct02.c b/testcases/kernel/syscalls/acct/acct02.c
index f61faf206..6c375d5cb 100644
--- a/testcases/kernel/syscalls/acct/acct02.c
+++ b/testcases/kernel/syscalls/acct/acct02.c
@@ -146,8 +146,20 @@ static void run(void)
 
 static void setup(void)
 {
+	struct statfs buf;
+
 	clock_ticks = SAFE_SYSCONF(_SC_CLK_TCK);
 
+	SAFE_STATFS(".", &buf);
+
+	float avail = (100.00 * buf.f_bavail) / buf.f_blocks;
+
+	if (avail < 4.1) {
+		tst_brk(TCONF,
+			"Less than 4.1%% (%.2f) of free space on filesystem",
+			avail);
+	}
+
 	TEST(acct(NULL));
 	if (TST_RET == -1)
 		tst_brk(TBROK | TTERRNO,
-- 
2.21.0

[LTP] [PATCH 2/2] syscalls/acct02: Fix failures with nearly full FS

[Yang Xu]

> While process accounting is running the kernel checks the percentage of
> available space on disk. If the accounting is enabled and the free space
> drops below 2% the accounting is disabled until we reach at least 4% of
> free space. Which especially means that we have to have more than 4% of
> free space when we start the accounting because we are starting in
> disabled state. And when accounting is disabled the data are dropped
> silently instead of being written to the file, which makes this test
> fail because we end up with an empty file.
>
> So this patch checks if there is at least 4.1% of free space before we
> start the test and exit with TCONF otherwise.
>
> Signed-off-by: Cyril Hrubis<chrubis@suse.cz>
> CC: Christian Amann<camann@suse.com>
> ---
>   testcases/kernel/syscalls/acct/acct02.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
>
> diff --git a/testcases/kernel/syscalls/acct/acct02.c b/testcases/kernel/syscalls/acct/acct02.c
> index f61faf206..6c375d5cb 100644
> --- a/testcases/kernel/syscalls/acct/acct02.c
> +++ b/testcases/kernel/syscalls/acct/acct02.c
> @@ -146,8 +146,20 @@ static void run(void)
>
>   static void setup(void)
>   {
> +	struct statfs buf;
> +
>   	clock_ticks = SAFE_SYSCONF(_SC_CLK_TCK);
>
> +	SAFE_STATFS(".",&buf);
> +
> +	float avail = (100.00 * buf.f_bavail) / buf.f_blocks;

Hi Cyril

  I met the same problem on last week when I ran acct02 on nearly full FS.  Since kernel/acct.c has defined the RESUME(4) and SUSPEND(2) macro,
4.1 is enough.  And I think we can leave a simple comment in here for why the limit is 4.1(even though the commit message has the reason).

Thanks
Yang Xu

> +
> +	if (avail<  4.1) {
> +		tst_brk(TCONF,
> +			"Less than 4.1%% (%.2f) of free space on filesystem",
> +			avail);
> +	}
> +
>   	TEST(acct(NULL));
>   	if (TST_RET == -1)
>   		tst_brk(TBROK | TTERRNO,

[LTP] [PATCH 2/2] syscalls/acct02: Fix failures with nearly full FS

[Cyril Hrubis]

Hi!
> I met the same problem on last week when I ran acct02 on nearly full
> FS.  Since kernel/acct.c has defined the RESUME(4) and SUSPEND(2)
> macro, 4.1 is enough.  And I think we can leave a simple comment in
> here for why the limit is 4.1(even though the commit message has the
> reason).

I guess that short comment would help there, if it's OK I will add it
before I push the patch.

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] [PATCH 2/2] syscalls/acct02: Fix failures with nearly full FS

[Yang Xu]

> Hi!
>> I met the same problem on last week when I ran acct02 on nearly full
>> FS.  Since kernel/acct.c has defined the RESUME(4) and SUSPEND(2)
>> macro, 4.1 is enough.  And I think we can leave a simple comment in
>> here for why the limit is 4.1(even though the commit message has the
>> reason).
> I guess that short comment would help there, if it's OK I will add it
> before I push the patch.
Hi

Yes, go ahead.