staging/lustre: Add debugfs root

This is just plumbing for migrating remaining procfs to
debugfs support

Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 153 insertions, 7 deletions

diff --git a/drivers/staging/lustre/lustre/include/lprocfs_status.h b/drivers/staging/lustre/lustre/include/lprocfs_status.h
index b46cd54f2081..313f39436d09 100644
--- a/drivers/staging/lustre/lustre/include/lprocfs_status.h
+++ b/drivers/staging/lustre/lustre/include/lprocfs_status.h
@@ -43,6 +43,7 @@
 #define _LPROCFS_SNMP_H
 
 #include <linux/proc_fs.h>
+#include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
@@ -349,7 +350,7 @@ enum {
 #define EXTRA_FIRST_OPC LDLM_GLIMPSE_ENQUEUE
 /* class_obd.c */
 extern struct proc_dir_entry *proc_lustre_root;
-
+extern struct dentry *debugfs_lustre_root;
 extern struct kobject *lustre_kobj;
 
 struct obd_device;
@@ -577,19 +578,30 @@ lprocfs_nid_stats_clear_write(struct file *file, const char *buffer,
 			      unsigned long count, void *data);
 extern int lprocfs_nid_stats_clear_read(struct seq_file *m, void *data);
 
+extern int ldebugfs_register_stats(struct dentry *parent,
+				   const char *name,
+				   struct lprocfs_stats *stats);
 extern int lprocfs_register_stats(struct proc_dir_entry *root, const char *name,
 				  struct lprocfs_stats *stats);
 
 /* lprocfs_status.c */
+extern int ldebugfs_add_vars(struct dentry *parent,
+			     struct lprocfs_vars *var,
+			     void *data);
 extern int lprocfs_add_vars(struct proc_dir_entry *root,
 			    struct lprocfs_vars *var,
 			    void *data);
 
+extern struct dentry *ldebugfs_register(const char *name,
+					struct dentry *parent,
+					struct lprocfs_vars *list,
+					void *data);
 extern struct proc_dir_entry *lprocfs_register(const char *name,
 					      struct proc_dir_entry *parent,
 					      struct lprocfs_vars *list,
 					      void *data);
 
+extern void ldebugfs_remove(struct dentry **entryp);
 extern void lprocfs_remove(struct proc_dir_entry **root);
 extern void lprocfs_remove_proc_entry(const char *name,
 				      struct proc_dir_entry *parent);
@@ -597,6 +609,11 @@ extern void lprocfs_remove_proc_entry(const char *name,
 extern int lprocfs_obd_setup(struct obd_device *obd, struct lprocfs_vars *list);
 extern int lprocfs_obd_cleanup(struct obd_device *obd);
 
+extern int ldebugfs_seq_create(struct dentry *parent,
+			       const char *name,
+			       umode_t mode,
+			       const struct file_operations *seq_fops,
+			       void *data);
 extern int lprocfs_seq_create(struct proc_dir_entry *parent, const char *name,
 			      umode_t mode,
 			      const struct file_operations *seq_fops,
@@ -691,7 +708,8 @@ extern int lprocfs_seq_release(struct inode *, struct file *);
 #define __LPROC_SEQ_FOPS(name, custom_seq_write)			\
 static int name##_single_open(struct inode *inode, struct file *file)	\
 {									\
-	return single_open(file, name##_seq_show, PDE_DATA(inode));	\
+	return single_open(file, name##_seq_show,			\
+			   inode->i_private ?: PDE_DATA(inode));	\
 }									\
 static struct file_operations name##_fops = {				\
 	.owner   = THIS_MODULE,					    \
@@ -736,7 +754,8 @@ static struct file_operations name##_fops = {				\
 	}								\
 	static int name##_##type##_open(struct inode *inode, struct file *file) \
 	{								\
-		return single_open(file, NULL, PDE_DATA(inode));	\
+		return single_open(file, NULL,				\
+				   inode->i_private ?: PDE_DATA(inode));\
 	}								\
 	static struct file_operations name##_##type##_fops = {	\
 		.open	= name##_##type##_open,				\
diff --git a/drivers/staging/lustre/lustre/obdclass/linux/linux-module.c b/drivers/staging/lustre/lustre/obdclass/linux/linux-module.c
index df3aa8fd253e..72113a915298 100644
--- a/drivers/staging/lustre/lustre/obdclass/linux/linux-module.c
+++ b/drivers/staging/lustre/lustre/obdclass/linux/linux-module.c
@@ -318,6 +318,10 @@ static ssize_t jobid_name_store(struct kobject *kobj, struct attribute *attr,
 	return count;
 }
 
+/* Root for /sys/kernel/debug/lustre */
+struct dentry *debugfs_lustre_root;
+EXPORT_SYMBOL_GPL(debugfs_lustre_root);
+
 #if defined(CONFIG_PROC_FS)
 /* Root for /proc/fs/lustre */
 struct proc_dir_entry *proc_lustre_root = NULL;
@@ -426,6 +430,7 @@ static struct attribute_group lustre_attr_group = {
 int class_procfs_init(void)
 {
 	int rc = 0;
+	struct dentry *file;
 
 	lustre_kobj = kobject_create_and_add("lustre", fs_kobj);
 	if (lustre_kobj == NULL)
@@ -438,8 +443,24 @@ int class_procfs_init(void)
 		goto out;
 	}
 
-	proc_lustre_root = lprocfs_register("fs/lustre", NULL,
-					    NULL, NULL);
+	debugfs_lustre_root = debugfs_create_dir("lustre", NULL);
+	if (IS_ERR_OR_NULL(debugfs_lustre_root)) {
+		rc = debugfs_lustre_root ? PTR_ERR(debugfs_lustre_root)
+					 : -ENOMEM;
+		debugfs_lustre_root = NULL;
+		kobject_put(lustre_kobj);
+		goto out;
+	}
+
+	file = debugfs_create_file("devices", 0444, debugfs_lustre_root, NULL,
+				   &obd_device_list_fops);
+	if (IS_ERR_OR_NULL(file)) {
+		rc = file ? PTR_ERR(file) : -ENOMEM;
+		kobject_put(lustre_kobj);
+		goto out;
+	}
+
+	proc_lustre_root = lprocfs_register("fs/lustre", NULL, NULL, NULL);
 	if (IS_ERR(proc_lustre_root)) {
 		rc = PTR_ERR(proc_lustre_root);
 		proc_lustre_root = NULL;
@@ -452,11 +473,16 @@ int class_procfs_init(void)
 out:
 	if (rc)
 		CERROR("error adding /proc/fs/lustre/devices file\n");
-	return 0;
+	return rc;
 }
 
 int class_procfs_clean(void)
 {
+	if (debugfs_lustre_root != NULL)
+		debugfs_remove_recursive(debugfs_lustre_root);
+
+	debugfs_lustre_root = NULL;
+
 	if (proc_lustre_root) {
 		lprocfs_remove(&proc_lustre_root);
 	}
diff --git a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
index 916d0606b2e4..000e8748da4a 100644
--- a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
+++ b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
@@ -296,6 +296,37 @@ EXPORT_SYMBOL(lprocfs_add_symlink);
 
 static struct file_operations lprocfs_generic_fops = { };
 
+int ldebugfs_add_vars(struct dentry *parent,
+		      struct lprocfs_vars *list,
+		      void *data)
+{
+	if (IS_ERR_OR_NULL(parent) || IS_ERR_OR_NULL(list))
+		return -EINVAL;
+
+	while (list->name != NULL) {
+		struct dentry *entry;
+		umode_t mode = 0;
+
+		if (list->proc_mode != 0000) {
+			mode = list->proc_mode;
+		} else if (list->fops) {
+			if (list->fops->read)
+				mode = 0444;
+			if (list->fops->write)
+				mode |= 0200;
+		}
+		entry = debugfs_create_file(list->name, mode, parent,
+					    list->data ?: data,
+					    list->fops ?: &lprocfs_generic_fops
+					   );
+		if (IS_ERR_OR_NULL(entry))
+			return entry ? PTR_ERR(entry) : -ENOMEM;
+		list++;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(ldebugfs_add_vars);
+
 /**
  * Add /proc entries.
  *
@@ -336,6 +367,13 @@ int lprocfs_add_vars(struct proc_dir_entry *root, struct lprocfs_vars *list,
 }
 EXPORT_SYMBOL(lprocfs_add_vars);
 
+void ldebugfs_remove(struct dentry **entryp)
+{
+	debugfs_remove(*entryp);
+	*entryp = NULL;
+}
+EXPORT_SYMBOL(ldebugfs_remove);
+
 void lprocfs_remove(struct proc_dir_entry **rooth)
 {
 	proc_remove(*rooth);
@@ -350,6 +388,32 @@ void lprocfs_remove_proc_entry(const char *name, struct proc_dir_entry *parent)
 }
 EXPORT_SYMBOL(lprocfs_remove_proc_entry);
 
+struct dentry *ldebugfs_register(const char *name,
+				 struct dentry *parent,
+				 struct lprocfs_vars *list, void *data)
+{
+	struct dentry *entry;
+
+	entry = debugfs_create_dir(name, parent);
+	if (IS_ERR_OR_NULL(entry)) {
+		entry = entry ?: ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	if (!IS_ERR_OR_NULL(list)) {
+		int rc;
+
+		rc = ldebugfs_add_vars(entry, list, data);
+		if (rc != 0) {
+			debugfs_remove(entry);
+			entry = ERR_PTR(rc);
+		}
+	}
+out:
+	return entry;
+}
+EXPORT_SYMBOL(ldebugfs_register);
+
 struct proc_dir_entry *lprocfs_register(const char *name,
 					struct proc_dir_entry *parent,
 					struct lprocfs_vars *list, void *data)
@@ -1257,8 +1321,10 @@ static int lprocfs_stats_seq_open(struct inode *inode, struct file *file)
 	rc = seq_open(file, &lprocfs_stats_seq_sops);
 	if (rc)
 		return rc;
+
 	seq = file->private_data;
-	seq->private = PDE_DATA(inode);
+	seq->private = inode->i_private ?: PDE_DATA(inode);
+
 	return 0;
 }
 
@@ -1271,6 +1337,22 @@ struct file_operations lprocfs_stats_seq_fops = {
 	.release = lprocfs_seq_release,
 };
 
+int ldebugfs_register_stats(struct dentry *parent, const char *name,
+			   struct lprocfs_stats *stats)
+{
+	struct dentry *entry;
+
+	LASSERT(!IS_ERR_OR_NULL(parent));
+
+	entry = debugfs_create_file(name, 0644, parent, stats,
+				    &lprocfs_stats_seq_fops);
+	if (IS_ERR_OR_NULL(entry))
+		return entry ? PTR_ERR(entry) : -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL(ldebugfs_register_stats);
+
 int lprocfs_register_stats(struct proc_dir_entry *root, const char *name,
 			   struct lprocfs_stats *stats)
 {
@@ -1971,6 +2053,25 @@ char *lprocfs_find_named_value(const char *buffer, const char *name,
 }
 EXPORT_SYMBOL(lprocfs_find_named_value);
 
+int ldebugfs_seq_create(struct dentry *parent,
+		       const char *name,
+		       umode_t mode,
+		       const struct file_operations *seq_fops,
+		       void *data)
+{
+	struct dentry *entry;
+
+	/* Disallow secretly (un)writable entries. */
+	LASSERT((seq_fops->write == NULL) == ((mode & 0222) == 0));
+
+	entry = debugfs_create_file(name, mode, parent, data, seq_fops);
+	if (IS_ERR_OR_NULL(entry))
+		return entry ? PTR_ERR(entry) : -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL(ldebugfs_seq_create);
+
 int lprocfs_seq_create(struct proc_dir_entry *parent,
 		       const char *name,
 		       umode_t mode,