proc: Generalize proc_sys_prune_dcache into proc_prune_siblings_dcache

This prepares the way for allowing the pid part of proc to use this
dcache pruning code as well.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
This commit is contained in:
Eric W. Biederman 2020-02-20 08:34:44 -06:00
Родитель 0afa5ca822
Коммит 26dbc60f38
3 изменённых файлов: 40 добавлений и 34 удалений

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@ -103,6 +103,44 @@ void __init proc_init_kmemcache(void)
BUILD_BUG_ON(sizeof(struct proc_dir_entry) >= SIZEOF_PDE);
}
void proc_prune_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock)
{
struct inode *inode;
struct proc_inode *ei;
struct hlist_node *node;
struct super_block *sb;
rcu_read_lock();
for (;;) {
node = hlist_first_rcu(inodes);
if (!node)
break;
ei = hlist_entry(node, struct proc_inode, sibling_inodes);
spin_lock(lock);
hlist_del_init_rcu(&ei->sibling_inodes);
spin_unlock(lock);
inode = &ei->vfs_inode;
sb = inode->i_sb;
if (!atomic_inc_not_zero(&sb->s_active))
continue;
inode = igrab(inode);
rcu_read_unlock();
if (unlikely(!inode)) {
deactivate_super(sb);
rcu_read_lock();
continue;
}
d_prune_aliases(inode);
iput(inode);
deactivate_super(sb);
rcu_read_lock();
}
rcu_read_unlock();
}
static int proc_show_options(struct seq_file *seq, struct dentry *root)
{
struct super_block *sb = root->d_sb;

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@ -210,6 +210,7 @@ extern const struct inode_operations proc_pid_link_inode_operations;
extern const struct super_operations proc_sops;
void proc_init_kmemcache(void);
void proc_prune_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock);
void set_proc_pid_nlink(void);
extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
extern void proc_entry_rundown(struct proc_dir_entry *);

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@ -269,40 +269,7 @@ static void unuse_table(struct ctl_table_header *p)
static void proc_sys_prune_dcache(struct ctl_table_header *head)
{
struct inode *inode;
struct proc_inode *ei;
struct hlist_node *node;
struct super_block *sb;
rcu_read_lock();
for (;;) {
node = hlist_first_rcu(&head->inodes);
if (!node)
break;
ei = hlist_entry(node, struct proc_inode, sibling_inodes);
spin_lock(&sysctl_lock);
hlist_del_init_rcu(&ei->sibling_inodes);
spin_unlock(&sysctl_lock);
inode = &ei->vfs_inode;
sb = inode->i_sb;
if (!atomic_inc_not_zero(&sb->s_active))
continue;
inode = igrab(inode);
rcu_read_unlock();
if (unlikely(!inode)) {
deactivate_super(sb);
rcu_read_lock();
continue;
}
d_prune_aliases(inode);
iput(inode);
deactivate_super(sb);
rcu_read_lock();
}
rcu_read_unlock();
proc_prune_siblings_dcache(&head->inodes, &sysctl_lock);
}
/* called under sysctl_lock, will reacquire if has to wait */