[PATCH 6/8] fuse_ctl: use simple_recursive_removal()

Al Viro
2025-06-14T06:02:33Z

easier that way - no need to keep that array of dentry references, etc.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/fuse/control.c | 30 +++++++++++++-----------------
fs/fuse/fuse_i.h | 6 ------
2 files changed, 13 insertions(+), 23 deletions(-)

diff --git a/fs/fuse/control.c b/fs/fuse/control.c
index 2a730d88cc3b..bb407705603c 100644
--- a/fs/fuse/control.c
+++ b/fs/fuse/control.c
@@ -11,6 +11,7 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs_context.h>
+#include <linux/namei.h>

#define FUSE_CTL_SUPER_MAGIC 0x65735543

@@ -212,7 +213,6 @@ static struct dentry *fuse_ctl_add_dentry(struct dentry *parent,
struct dentry *dentry;
struct inode *inode;

- BUG_ON(fc->ctl_ndents >= FUSE_CTL_NUM_DENTRIES);
dentry = d_alloc_name(parent, name);
if (!dentry)
return NULL;
@@ -236,8 +236,6 @@ static struct dentry *fuse_ctl_add_dentry(struct dentry *parent,
inode->i_private = fc;
d_add(dentry, inode);

- fc->ctl_dentry[fc->ctl_ndents++] = dentry;
-
return dentry;
}

@@ -280,27 +278,29 @@ int fuse_ctl_add_conn(struct fuse_conn *fc)
return -ENOMEM;
}

+static void remove_one(struct dentry *dentry)
+{
+ d_inode(dentry)->i_private = NULL;
+}
+
/*
* Remove a connection from the control filesystem (if it exists).
* Caller must hold fuse_mutex
*/
void fuse_ctl_remove_conn(struct fuse_conn *fc)
{
- int i;
+ struct dentry *dentry;
+ char name[32];

if (!fuse_control_sb || fc->no_control)
return;

- for (i = fc->ctl_ndents - 1; i >= 0; i--) {
- struct dentry *dentry = fc->ctl_dentry[i];
- d_inode(dentry)->i_private = NULL;
- if (!i) {
- /* Get rid of submounts: */
- d_invalidate(dentry);
- }
- dput(dentry);
+ sprintf(name, "%u", fc->dev);
+ dentry = lookup_noperm_positive_unlocked(&QSTR(name), fuse_control_sb->s_root);
+ if (!IS_ERR(dentry)) {
+ simple_recursive_removal(dentry, remove_one);
+ dput(dentry); // paired with lookup_noperm_positive_unlocked()
}
- drop_nlink(d_inode(fuse_control_sb->s_root));
}

static int fuse_ctl_fill_super(struct super_block *sb, struct fs_context *fsc)
@@ -346,12 +346,8 @@ static int fuse_ctl_init_fs_context(struct fs_context *fsc)

static void fuse_ctl_kill_sb(struct super_block *sb)
{
- struct fuse_conn *fc;
-
mutex_lock(&fuse_mutex);
fuse_control_sb = NULL;
- list_for_each_entry(fc, &fuse_conn_list, entry)
- fc->ctl_ndents = 0;
mutex_unlock(&fuse_mutex);

kill_litter_super(sb);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index b54f4f57789f..30206605e114 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -913,12 +913,6 @@ struct fuse_conn {
/** Device ID from the root super block */
dev_t dev;

- /** Dentries in the control filesystem */
- struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
-
- /** number of dentries used in the above array */
- int ctl_ndents;
-
/** Key for lock owner ID scrambling */
u32 scramble_key[4];

--
2.39.5