[PATCH v7 07/10] ref_tracker: add a way to create a symlink to the ref_tracker_dir debugfs file
Jeff Layton
jlayton at kernel.org
Mon May 5 17:33:21 UTC 2025
Add the ability for a subsystem to add a user-friendly symlink that
points to a ref_tracker_dir's debugfs file.
Signed-off-by: Jeff Layton <jlayton at kernel.org>
---
include/linux/ref_tracker.h | 11 +++++++++++
lib/ref_tracker.c | 28 ++++++++++++++++++++++++++++
2 files changed, 39 insertions(+)
diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h
index 17d5924d595ce95bfb5d8ec6d813490499bd89d0..b27cb7b3f1be5e16dedceeb0a88e9aa577be5dff 100644
--- a/include/linux/ref_tracker.h
+++ b/include/linux/ref_tracker.h
@@ -22,6 +22,7 @@ struct ref_tracker_dir {
const char *class; /* object classname */
#ifdef CONFIG_DEBUG_FS
struct dentry *dentry;
+ struct dentry *symlink;
#endif
char name[32];
#endif
@@ -30,6 +31,7 @@ struct ref_tracker_dir {
#ifdef CONFIG_REF_TRACKER
void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir);
+void ref_tracker_dir_symlink(struct ref_tracker_dir *dir, const char *fmt, ...);
static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
unsigned int quarantine_count,
@@ -46,6 +48,7 @@ static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
dir->class = class;
#ifdef CONFIG_DEBUG_FS
dir->dentry = NULL;
+ dir->symlink = NULL;
#endif
strscpy(dir->name, name, sizeof(dir->name));
ref_tracker_dir_debugfs(dir);
@@ -81,6 +84,10 @@ static inline void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir)
{
}
+static inline void ref_tracker_dir_symlink(struct ref_tracker_dir *dir, const char *fmt, ...)
+{
+}
+
static inline void ref_tracker_dir_exit(struct ref_tracker_dir *dir)
{
}
@@ -114,6 +121,10 @@ static inline int ref_tracker_free(struct ref_tracker_dir *dir,
return 0;
}
+static inline __ostream_printf
+void ref_tracker_dir_symlink(struct ref_tracker_dir *dir, const char *fmt, ...)
+{
+}
#endif
#endif /* _LINUX_REF_TRACKER_H */
diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c
index 723df31321242d6af267986cc56a9d80b6e5ad18..d59ef7200dd4f97f247ddd989beb5757b8afd519 100644
--- a/lib/ref_tracker.c
+++ b/lib/ref_tracker.c
@@ -390,8 +390,36 @@ void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir)
}
EXPORT_SYMBOL(ref_tracker_dir_debugfs);
+void __ostream_printf ref_tracker_dir_symlink(struct ref_tracker_dir *dir, const char *fmt, ...)
+{
+ char name[NAME_MAX + 1];
+ va_list args;
+ int ret;
+
+ /* Already created, or dentry doesn't exist? Do nothing */
+ if (!IS_ERR_OR_NULL(dir->symlink) || IS_ERR_OR_NULL(dir->dentry))
+ return;
+
+ va_start(args, fmt);
+ ret = vsnprintf(name, sizeof(name), fmt, args);
+ va_end(args);
+ name[sizeof(name) - 1] = '\0';
+
+ if (ret < sizeof(name))
+ dir->symlink = debugfs_create_symlink(name, ref_tracker_debug_dir,
+ dir->dentry->d_name.name);
+ else
+ dir->symlink = ERR_PTR(-ENAMETOOLONG);
+
+ if (IS_ERR(dir->symlink))
+ pr_warn("ref_tracker: unable to create debugfs symlink for %s: %pe\n",
+ name, dir->symlink);
+}
+EXPORT_SYMBOL(ref_tracker_dir_symlink);
+
static void ref_tracker_debugfs_remove(struct ref_tracker_dir *dir)
{
+ debugfs_remove(dir->symlink);
debugfs_remove(dir->dentry);
}
--
2.49.0
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