[PATCH 1/2] xfs: create scaffolding for creating debugfs entries

Darrick J. Wong
2023-07-27T22:27:28Z

Set up debugfs directories for xfs as a whole, and a subdirectory for
each mounted filesystem. This will enable the creation of debugfs files
in the next patch.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/xfs_linux.h | 1 +
fs/xfs/xfs_mount.h | 1 +
fs/xfs/xfs_super.c | 32 ++++++++++++++++++++++++++++++--
fs/xfs/xfs_super.h | 2 ++
4 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
index 74dcb05069e89..e9d317a3dafe4 100644
--- a/fs/xfs/xfs_linux.h
+++ b/fs/xfs/xfs_linux.h
@@ -63,6 +63,7 @@ typedef __u32 xfs_nlink_t;
#include <linux/rhashtable.h>
#include <linux/xattr.h>
#include <linux/mnt_idmapping.h>
+#include <linux/debugfs.h>

#include <asm/page.h>
#include <asm/div64.h>
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index e2866e7fa60c2..0b86bf10a4cc3 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -208,6 +208,7 @@ typedef struct xfs_mount {
uint64_t m_resblks_avail;/* available reserved blocks */
uint64_t m_resblks_save; /* reserved blks @ remount,ro */
struct delayed_work m_reclaim_work; /* background inode reclaim */
+ struct dentry *m_debugfs; /* debugfs parent */
struct xfs_kobj m_kobj;
struct xfs_kobj m_error_kobj;
struct xfs_kobj m_error_meta_kobj;
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 8185102431301..31ac4744fdbec 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -49,6 +49,7 @@

static const struct super_operations xfs_super_operations;

+static struct dentry *xfs_debugfs; /* top-level xfs debugfs dir */
static struct kset *xfs_kset; /* top-level xfs sysfs dir */
#ifdef DEBUG
static struct xfs_kobj xfs_dbg_kobj; /* global debug sysfs attrs */
@@ -758,6 +759,7 @@ static void
xfs_mount_free(
struct xfs_mount *mp)
{
+ debugfs_remove(mp->m_debugfs);
kfree(mp->m_rtname);
kfree(mp->m_logname);
kmem_free(mp);
@@ -1479,6 +1481,21 @@ xfs_fs_validate_params(
return 0;
}

+struct dentry *
+xfs_debugfs_mkdir(
+ const char *name,
+ struct dentry *parent)
+{
+ struct dentry *child;
+
+ /* Apparently we're expected to ignore error returns?? */
+ child = debugfs_create_dir(name, parent);
+ if (IS_ERR(child))
+ return NULL;
+
+ return child;
+}
+
static int
xfs_fs_fill_super(
struct super_block *sb,
@@ -1521,6 +1538,13 @@ xfs_fs_fill_super(
if (error)
goto out_free_names;

+ if (xfs_debugfs) {
+ mp->m_debugfs = xfs_debugfs_mkdir(mp->m_super->s_id,
+ xfs_debugfs);
+ } else {
+ mp->m_debugfs = NULL;
+ }
+
error = xfs_init_mount_workqueues(mp);
if (error)
goto out_close_devices;
@@ -2353,10 +2377,12 @@ init_xfs_fs(void)
if (error)
goto out_cleanup_procfs;

+ xfs_debugfs = xfs_debugfs_mkdir("xfs", NULL);
+
xfs_kset = kset_create_and_add("xfs", NULL, fs_kobj);
if (!xfs_kset) {
error = -ENOMEM;
- goto out_sysctl_unregister;
+ goto out_debugfs_unregister;
}

xfsstats.xs_kobj.kobject.kset = xfs_kset;
@@ -2400,7 +2426,8 @@ init_xfs_fs(void)
free_percpu(xfsstats.xs_stats);
out_kset_unregister:
kset_unregister(xfs_kset);
- out_sysctl_unregister:
+ out_debugfs_unregister:
+ debugfs_remove(xfs_debugfs);
xfs_sysctl_unregister();
out_cleanup_procfs:
xfs_cleanup_procfs();
@@ -2427,6 +2454,7 @@ exit_xfs_fs(void)
xfs_sysfs_del(&xfsstats.xs_kobj);
free_percpu(xfsstats.xs_stats);
kset_unregister(xfs_kset);
+ debugfs_remove(xfs_debugfs);
xfs_sysctl_unregister();
xfs_cleanup_procfs();
xfs_mru_cache_uninit();
diff --git a/fs/xfs/xfs_super.h b/fs/xfs/xfs_super.h
index 364e2c2648a8a..302e6e5d6c7e2 100644
--- a/fs/xfs/xfs_super.h
+++ b/fs/xfs/xfs_super.h
@@ -100,4 +100,6 @@ extern struct workqueue_struct *xfs_discard_wq;

#define XFS_M(sb) ((struct xfs_mount *)((sb)->s_fs_info))

+struct dentry *xfs_debugfs_mkdir(const char *name, struct dentry *parent);
+
#endif /* __XFS_SUPER_H__ */