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SPDX-License-Identifier: GPL-2.0
diff --git a/fs/mount.h b/fs/mount.h
index 711a4093e475..a5703d5c7205 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -133,9 +133,7 @@ struct proc_mounts {
struct mnt_namespace *ns;
struct path root;
int (*show)(struct seq_file *, struct vfsmount *);
- void *cached_mount;
- u64 cached_event;
- loff_t cached_index;
+ size_t filled;
};
extern const struct seq_operations mounts_op;
diff --git a/fs/namespace.c b/fs/namespace.c
index 85b5f7bea82e..ff398173c36f 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1246,46 +1246,80 @@ struct vfsmount *mnt_clone_internal(const struct path *path)
#ifdef CONFIG_PROC_FS
/* iterator; we want it to have access to namespace_sem, thus here... */
-static void *m_start(struct seq_file *m, loff_t *pos)
+static int m_start_fill(struct seq_file *m)
{
+ int err;
+ size_t last_count;
+ char *buf;
+ struct mount *r;
struct proc_mounts *p = m->private;
+ err = -ENODATA;
+ m->count = 0;
down_read(&namespace_sem);
- if (p->cached_event == p->ns->event) {
- void *v = p->cached_mount;
- if (*pos == p->cached_index)
- return v;
- if (*pos == p->cached_index + 1) {
- v = seq_list_next(v, &p->ns->list, &p->cached_index);
- return p->cached_mount = v;
+ list_for_each_entry(r, &p->ns->list, mnt_list) {
+ last_count = m->count;
+ err = p->show(m, &r->mnt);
+ if (unlikely(err < 0))
+ break;
+ if (!seq_has_overflowed(m))
+ continue;
+
+ /* expand the buffer */
+ buf = kvmalloc(m->size + PAGE_SIZE, GFP_KERNEL);
+ if (unlikely(!buf)) {
+ err = -ENOMEM;
+ break;
+ }
+ memcpy(buf, m->buf, last_count);
+ kvfree(m->buf);
+ m->buf = buf;
+ m->size += PAGE_SIZE;
+ m->count = last_count;
+
+#if 0 /* todo: consider the limit */
+ err = p->show(m, &r->mnt);
+ if (unlikely(err < 0))
+ break;
+ else if (unlikely(seq_has_overflowed(m))) {
+ err = -EOVERFLOW;
+ break;
}
+#endif
}
+ up_read(&namespace_sem);
- p->cached_event = p->ns->event;
- p->cached_mount = seq_list_start(&p->ns->list, *pos);
- p->cached_index = *pos;
- return p->cached_mount;
+ if (!err)
+ p->filled = m->count;
+ return err;
}
-static void *m_next(struct seq_file *m, void *v, loff_t *pos)
+static void *m_start(struct seq_file *m, loff_t *pos)
{
- struct proc_mounts *p = m->private;
+ int err;
- p->cached_mount = seq_list_next(v, &p->ns->list, pos);
- p->cached_index = *pos;
- return p->cached_mount;
+ if (!*pos) {
+ err = m_start_fill(m);
+ if (unlikely(err))
+ return ERR_PTR(err);
+ }
+
+ return m_start; /* any valid pointer */
+}
+
+static void *m_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ return NULL;
}
static void m_stop(struct seq_file *m, void *v)
{
- up_read(&namespace_sem);
+ /* empty */
}
static int m_show(struct seq_file *m, void *v)
{
- struct proc_mounts *p = m->private;
- struct mount *r = list_entry(v, struct mount, mnt_list);
- return p->show(m, &r->mnt);
+ return 0;
}
const struct seq_operations mounts_op = {
diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 273ee82d8aa9..e5b22c50ca59 100644
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -279,7 +279,6 @@ static int mounts_open_common(struct inode *inode, struct file *file,
p->ns = ns;
p->root = root;
p->show = show;
- p->cached_event = ~0ULL;
return 0;