procfs: move dropping pde and pid from ->evict_inode() to ->free_inode()

that keeps both around until struct inode is freed, making access
to them safe from rcu-pathwalk

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2023-09-19 23:52:58 -04:00
parent c1b967d03c
commit 47458802f6
2 changed files with 8 additions and 13 deletions

View File

@ -1878,8 +1878,6 @@ void proc_pid_evict_inode(struct proc_inode *ei)
hlist_del_init_rcu(&ei->sibling_inodes);
spin_unlock(&pid->lock);
}
put_pid(pid);
}
struct inode *proc_pid_make_inode(struct super_block *sb,

View File

@ -30,7 +30,6 @@
static void proc_evict_inode(struct inode *inode)
{
struct proc_dir_entry *de;
struct ctl_table_header *head;
struct proc_inode *ei = PROC_I(inode);
@ -38,17 +37,8 @@ static void proc_evict_inode(struct inode *inode)
clear_inode(inode);
/* Stop tracking associated processes */
if (ei->pid) {
if (ei->pid)
proc_pid_evict_inode(ei);
ei->pid = NULL;
}
/* Let go of any associated proc directory entry */
de = ei->pde;
if (de) {
pde_put(de);
ei->pde = NULL;
}
head = ei->sysctl;
if (head) {
@ -80,6 +70,13 @@ static struct inode *proc_alloc_inode(struct super_block *sb)
static void proc_free_inode(struct inode *inode)
{
struct proc_inode *ei = PROC_I(inode);
if (ei->pid)
put_pid(ei->pid);
/* Let go of any associated proc directory entry */
if (ei->pde)
pde_put(ei->pde);
kmem_cache_free(proc_inode_cachep, PROC_I(inode));
}