[06/15] procfs: move dropping pde and pid from ->evict_inode() to ->free_inode()

Commit Message

Al Viro Oct. 2, 2023, 2:32 a.m. UTC

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

Signed-off-by: Al Viro <[e-mail]>
---
 fs/proc/base.c  |  2 --
 fs/proc/inode.c | 19 ++++++++-----------
 2 files changed, 8 insertions(+), 13 deletions(-)

Patch

diff --git a/fs/proc/base.c b/fs/proc/base.c
index ffd54617c354..8e93b11a0fed 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1881,8 +1881,6 @@  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,
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 532dc9d240f7..c83e1a55da42 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -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));
 }