[PATCH] fs/dlm: use scnprintf() in lockspace show funcs

[PATCH] fs/dlm: use scnprintf() in lockspace show funcs

[Pranav Tyagi]

Replace all snprintf() instances with scnprintf(). snprintf() returns
the number of bytes that would have been written had there been enough
space. For sysfs attributes, snprintf() should not be used for the
show() method. Instead use scnprintf() which returns the number of
bytes actually written.

Signed-off-by: Pranav Tyagi <pranav.tyagi03@gmail.com>
---
 fs/dlm/config.c    | 2 +-
 fs/dlm/lockspace.c | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/dlm/config.c b/fs/dlm/config.c
index a23fd524a6ee..10486a46a540 100644
--- a/fs/dlm/config.c
+++ b/fs/dlm/config.c
@@ -185,7 +185,7 @@ static ssize_t cluster_##name##_store(struct config_item *item, \
 }                                                                             \
 static ssize_t cluster_##name##_show(struct config_item *item, char *buf)     \
 {                                                                             \
-	return snprintf(buf, PAGE_SIZE, "%u\n", dlm_config.ci_##name);        \
+	return scnprintf(buf, PAGE_SIZE, "%u\n", dlm_config.ci_##name);       \
 }                                                                             \
 CONFIGFS_ATTR(cluster_, name);
 
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 1929327ffbe1..2e83e381e54c 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -69,7 +69,7 @@ static ssize_t dlm_event_store(struct dlm_ls *ls, const char *buf, size_t len)
 
 static ssize_t dlm_id_show(struct dlm_ls *ls, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%u\n", ls->ls_global_id);
+	return scnprintf(buf, PAGE_SIZE, "%u\n", ls->ls_global_id);
 }
 
 static ssize_t dlm_id_store(struct dlm_ls *ls, const char *buf, size_t len)
@@ -83,7 +83,7 @@ static ssize_t dlm_id_store(struct dlm_ls *ls, const char *buf, size_t len)
 
 static ssize_t dlm_nodir_show(struct dlm_ls *ls, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%u\n", dlm_no_directory(ls));
+	return scnprintf(buf, PAGE_SIZE, "%u\n", dlm_no_directory(ls));
 }
 
 static ssize_t dlm_nodir_store(struct dlm_ls *ls, const char *buf, size_t len)
@@ -101,12 +101,12 @@ static ssize_t dlm_nodir_store(struct dlm_ls *ls, const char *buf, size_t len)
 static ssize_t dlm_recover_status_show(struct dlm_ls *ls, char *buf)
 {
 	uint32_t status = dlm_recover_status(ls);
-	return snprintf(buf, PAGE_SIZE, "%x\n", status);
+	return scnprintf(buf, PAGE_SIZE, "%x\n", status);
 }
 
 static ssize_t dlm_recover_nodeid_show(struct dlm_ls *ls, char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", ls->ls_recover_nodeid);
+	return scnprintf(buf, PAGE_SIZE, "%d\n", ls->ls_recover_nodeid);
 }
 
 struct dlm_attr {
-- 
2.49.0

Re: [PATCH] fs/dlm: use scnprintf() in lockspace show funcs

[Greg KH]

On Mon, Jun 16, 2025 at 04:04:41PM +0530, Pranav Tyagi wrote:
> Replace all snprintf() instances with scnprintf(). snprintf() returns
> the number of bytes that would have been written had there been enough
> space. For sysfs attributes, snprintf() should not be used for the
> show() method. Instead use scnprintf() which returns the number of
> bytes actually written.
> 
> Signed-off-by: Pranav Tyagi <pranav.tyagi03@gmail.com>
> ---
>  fs/dlm/config.c    | 2 +-
>  fs/dlm/lockspace.c | 8 ++++----
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/dlm/config.c b/fs/dlm/config.c
> index a23fd524a6ee..10486a46a540 100644
> --- a/fs/dlm/config.c
> +++ b/fs/dlm/config.c
> @@ -185,7 +185,7 @@ static ssize_t cluster_##name##_store(struct config_item *item, \
>  }                                                                             \
>  static ssize_t cluster_##name##_show(struct config_item *item, char *buf)     \
>  {                                                                             \
> -	return snprintf(buf, PAGE_SIZE, "%u\n", dlm_config.ci_##name);        \
> +	return scnprintf(buf, PAGE_SIZE, "%u\n", dlm_config.ci_##name);       \

sysfs_emit() or no change at all please.