[v3,1/3] Add tst_purge_dir() helper function
diff mbox series

Message ID 20200123162019.18958-2-mdoucha@suse.cz
State Superseded
Headers show
Series
  • Add test for misaligned fallocate()
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Commit Message

Martin Doucha Jan. 23, 2020, 4:20 p.m. UTC
This function deletes the contents of the given directory while leaving
the directory itself intact. Useful for purging the mountpoint between test
iterations or test cases.

Signed-off-by: Martin Doucha <mdoucha@suse.cz>
---
 include/tst_device.h |   5 ++
 lib/tst_tmpdir.c     | 106 +++++++++++++++++++++++++++----------------
 2 files changed, 73 insertions(+), 38 deletions(-)

Comments

Cyril Hrubis Jan. 24, 2020, 10:23 a.m. UTC | #1
Hi!
> This function deletes the contents of the given directory while leaving
> the directory itself intact. Useful for purging the mountpoint between test
> iterations or test cases.
> 
> Signed-off-by: Martin Doucha <mdoucha@suse.cz>
> ---
>  include/tst_device.h |   5 ++
>  lib/tst_tmpdir.c     | 106 +++++++++++++++++++++++++++----------------
>  2 files changed, 73 insertions(+), 38 deletions(-)
> 
> diff --git a/include/tst_device.h b/include/tst_device.h
> index 3db5275c9..d2e4ad5be 100644
> --- a/include/tst_device.h
> +++ b/include/tst_device.h
> @@ -88,4 +88,9 @@ static inline int tst_dev_sync(int fd)
>   */
>  unsigned long tst_dev_bytes_written(const char *dev);
>  
> +/*
> + *Wipe the contents of given directory but keep the directory itself
> + */
> +void tst_purge_dir(const char *path);

I'm not sure that it belongs to tst_device.h.

We do have functions such as tst_dir_is_empty() in tst_fs.h so maybe
that would be a slightly better fit.

>  #endif	/* TST_DEVICE_H__ */
> diff --git a/lib/tst_tmpdir.c b/lib/tst_tmpdir.c
> index 09b7b6e22..4b21dfad6 100644
> --- a/lib/tst_tmpdir.c
> +++ b/lib/tst_tmpdir.c
> @@ -99,6 +99,8 @@ static char test_start_work_dir[PATH_MAX];
>  /* lib/tst_checkpoint.c */
>  extern futex_t *tst_futexes;
>  
> +static int rmobj(const char *obj, char **errmsg);
> +
>  int tst_tmpdir_created(void)
>  {
>  	return TESTDIR != NULL;
> @@ -119,60 +121,80 @@ const char *tst_get_startwd(void)
>  	return test_start_work_dir;
>  }
>  
> -static int rmobj(char *obj, char **errmsg)
> +static int purge_dir(const char *path, char **errptr)
>  {
>  	int ret_val = 0;
>  	DIR *dir;
>  	struct dirent *dir_ent;
>  	char dirobj[PATH_MAX];
> -	struct stat statbuf;
>  	static char err_msg[1024];
>  	int fd;
>  
> -	fd = open(obj, O_DIRECTORY | O_NOFOLLOW);
> -	if (fd != -1) {
> -		close(fd);
> +	errno = 0;
> +	fd = open(path, O_DIRECTORY | O_NOFOLLOW);
>  
> -		/* Do NOT perform the request if the directory is "/" */
> -		if (!strcmp(obj, "/")) {
> -			if (errmsg != NULL) {
> -				sprintf(err_msg, "Cannot remove /");
> -				*errmsg = err_msg;
> -			}
> -			return -1;
> +	if (fd < 0) {
> +		if (errptr) {
> +			sprintf(err_msg,
> +				"Cannot open directory %s; errno=%d: %s",
> +				path, errno, tst_strerrno(errno));
> +			*errptr = err_msg;
>  		}

Isn't this check useless here? Or are we trying to avoid escaping the
directory via symlink?

If that's so maybe we should make it more obvious with stat() and
S_ISLNK(), or at least add a comment.

Also it would be nice to add an paragraph describing this function into
the doc/test-writing-guidelines.txt
Martin Doucha Jan. 24, 2020, 12:09 p.m. UTC | #2
On 1/24/20 11:23 AM, Cyril Hrubis wrote:
>> -	fd = open(obj, O_DIRECTORY | O_NOFOLLOW);
>> -	if (fd != -1) {
>> -		close(fd);
>> +	errno = 0;
>> +	fd = open(path, O_DIRECTORY | O_NOFOLLOW);
>>  
>> -		/* Do NOT perform the request if the directory is "/" */
>> -		if (!strcmp(obj, "/")) {
>> -			if (errmsg != NULL) {
>> -				sprintf(err_msg, "Cannot remove /");
>> -				*errmsg = err_msg;
>> -			}
>> -			return -1;
>> +	if (fd < 0) {
>> +		if (errptr) {
>> +			sprintf(err_msg,
>> +				"Cannot open directory %s; errno=%d: %s",
>> +				path, errno, tst_strerrno(errno));
>> +			*errptr = err_msg;
>>  		}
> 
> Isn't this check useless here? Or are we trying to avoid escaping the
> directory via symlink?

You're right. I've just blindly copied the check from rmobj() which uses
it to decide whether the FS node should be removed using rmdir() or
unlink(). I'll move the open() check to tst_purge_dir() so it doesn't
get called twice for each subdirectory and drop the useless O_NOFOLLOW.

Patch
diff mbox series

diff --git a/include/tst_device.h b/include/tst_device.h
index 3db5275c9..d2e4ad5be 100644
--- a/include/tst_device.h
+++ b/include/tst_device.h
@@ -88,4 +88,9 @@  static inline int tst_dev_sync(int fd)
  */
 unsigned long tst_dev_bytes_written(const char *dev);
 
+/*
+ *Wipe the contents of given directory but keep the directory itself
+ */
+void tst_purge_dir(const char *path);
+
 #endif	/* TST_DEVICE_H__ */
diff --git a/lib/tst_tmpdir.c b/lib/tst_tmpdir.c
index 09b7b6e22..4b21dfad6 100644
--- a/lib/tst_tmpdir.c
+++ b/lib/tst_tmpdir.c
@@ -99,6 +99,8 @@  static char test_start_work_dir[PATH_MAX];
 /* lib/tst_checkpoint.c */
 extern futex_t *tst_futexes;
 
+static int rmobj(const char *obj, char **errmsg);
+
 int tst_tmpdir_created(void)
 {
 	return TESTDIR != NULL;
@@ -119,60 +121,80 @@  const char *tst_get_startwd(void)
 	return test_start_work_dir;
 }
 
-static int rmobj(char *obj, char **errmsg)
+static int purge_dir(const char *path, char **errptr)
 {
 	int ret_val = 0;
 	DIR *dir;
 	struct dirent *dir_ent;
 	char dirobj[PATH_MAX];
-	struct stat statbuf;
 	static char err_msg[1024];
 	int fd;
 
-	fd = open(obj, O_DIRECTORY | O_NOFOLLOW);
-	if (fd != -1) {
-		close(fd);
+	errno = 0;
+	fd = open(path, O_DIRECTORY | O_NOFOLLOW);
 
-		/* Do NOT perform the request if the directory is "/" */
-		if (!strcmp(obj, "/")) {
-			if (errmsg != NULL) {
-				sprintf(err_msg, "Cannot remove /");
-				*errmsg = err_msg;
-			}
-			return -1;
+	if (fd < 0) {
+		if (errptr) {
+			sprintf(err_msg,
+				"Cannot open directory %s; errno=%d: %s",
+				path, errno, tst_strerrno(errno));
+			*errptr = err_msg;
 		}
 
-		/* Open the directory to get access to what is in it */
-		if ((dir = opendir(obj)) == NULL) {
-			if (rmdir(obj) != 0) {
-				if (errmsg != NULL) {
-					sprintf(err_msg,
-						"rmdir(%s) failed; errno=%d: %s",
-						obj, errno, tst_strerrno(errno));
-					*errmsg = err_msg;
-				}
-				return -1;
-			} else {
-				return 0;
-			}
-		}
+		return -1;
+	}
 
-		/* Loop through the entries in the directory, removing each one */
-		for (dir_ent = (struct dirent *)readdir(dir);
-		     dir_ent != NULL; dir_ent = (struct dirent *)readdir(dir)) {
+	close(fd);
 
-			/* Don't remove "." or ".." */
-			if (!strcmp(dir_ent->d_name, ".")
-			    || !strcmp(dir_ent->d_name, ".."))
-				continue;
+	/* Do NOT perform the request if the directory is "/" */
+	if (!strcmp(path, "/")) {
+		if (errptr) {
+			strcpy(err_msg, "Cannot purge system root directory");
+			*errptr = err_msg;
+		}
 
-			/* Recursively call this routine to remove the current entry */
-			sprintf(dirobj, "%s/%s", obj, dir_ent->d_name);
-			if (rmobj(dirobj, errmsg) != 0)
-				ret_val = -1;
+		return -1;
+	}
+
+	/* Open the directory to get access to what is in it */
+	if (!(dir = opendir(path))) {
+		if (errptr) {
+			sprintf(err_msg,
+				"Cannot open directory %s; errno=%d: %s",
+				path, errno, tst_strerrno(errno));
+			*errptr = err_msg;
 		}
+		return -1;
+	}
+
+	/* Loop through the entries in the directory, removing each one */
+	for (dir_ent = readdir(dir); dir_ent; dir_ent = readdir(dir)) {
+		/* Don't remove "." or ".." */
+		if (!strcmp(dir_ent->d_name, ".")
+		    || !strcmp(dir_ent->d_name, ".."))
+			continue;
+
+		/* Recursively remove the current entry */
+		sprintf(dirobj, "%s/%s", path, dir_ent->d_name);
+		if (rmobj(dirobj, errptr) != 0)
+			ret_val = -1;
+	}
+
+	closedir(dir);
+	return ret_val;
+}
+
+static int rmobj(const char *obj, char **errmsg)
+{
+	int ret_val = 0;
+	struct stat statbuf;
+	static char err_msg[1024];
+	int fd;
 
-		closedir(dir);
+	fd = open(obj, O_DIRECTORY | O_NOFOLLOW);
+	if (fd >= 0) {
+		close(fd);
+		ret_val = purge_dir(obj, errmsg);
 
 		/* If there were problems removing an entry, don't attempt to
 		   remove the directory itself */
@@ -330,3 +352,11 @@  void tst_rmdir(void)
 			 __func__, TESTDIR, errmsg);
 	}
 }
+
+void tst_purge_dir(const char *path)
+{
+	char *err;
+
+	if (purge_dir(path, &err))
+		tst_brkm(TBROK, NULL, "%s: %s", __func__, err);
+}