1 files changed, 38 insertions, 14 deletions

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 8a40e15f5ecb..b5e7155d30d8 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -20,6 +20,7 @@
 #include <linux/namei.h>
 #include <linux/bitops.h>
 #include <linux/spinlock.h>
+#include <linux/completion.h>
 #include <asm/uaccess.h>
 
 #include "internal.h"
@@ -529,12 +530,6 @@ static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp
 		return -EAGAIN;
 	dp->low_ino = i;
 
-	spin_lock(&proc_subdir_lock);
-	dp->next = dir->subdir;
-	dp->parent = dir;
-	dir->subdir = dp;
-	spin_unlock(&proc_subdir_lock);
-
 	if (S_ISDIR(dp->mode)) {
 		if (dp->proc_iops == NULL) {
 			dp->proc_fops = &proc_dir_operations;
@@ -550,6 +545,13 @@ static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp
 		if (dp->proc_iops == NULL)
 			dp->proc_iops = &proc_file_inode_operations;
 	}
+
+	spin_lock(&proc_subdir_lock);
+	dp->next = dir->subdir;
+	dp->parent = dir;
+	dir->subdir = dp;
+	spin_unlock(&proc_subdir_lock);
+
 	return 0;
 }
 
@@ -613,6 +615,9 @@ static struct proc_dir_entry *proc_create(struct proc_dir_entry **parent,
 	ent->namelen = len;
 	ent->mode = mode;
 	ent->nlink = nlink;
+	ent->pde_users = 0;
+	spin_lock_init(&ent->pde_unload_lock);
+	ent->pde_unload_completion = NULL;
  out:
 	return ent;
 }
@@ -649,9 +654,6 @@ struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode,
 
 	ent = proc_create(&parent, name, S_IFDIR | mode, 2);
 	if (ent) {
-		ent->proc_fops = &proc_dir_operations;
-		ent->proc_iops = &proc_dir_inode_operations;
-
 		if (proc_register(parent, ent) < 0) {
 			kfree(ent);
 			ent = NULL;
@@ -686,10 +688,6 @@ struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
 
 	ent = proc_create(&parent,name,mode,nlink);
 	if (ent) {
-		if (S_ISDIR(mode)) {
-			ent->proc_fops = &proc_dir_operations;
-			ent->proc_iops = &proc_dir_inode_operations;
-		}
 		if (proc_register(parent, ent) < 0) {
 			kfree(ent);
 			ent = NULL;
@@ -734,9 +732,35 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
 		de = *p;
 		*p = de->next;
 		de->next = NULL;
+
+		spin_lock(&de->pde_unload_lock);
+		/*
+		 * Stop accepting new callers into module. If you're
+		 * dynamically allocating ->proc_fops, save a pointer somewhere.
+		 */
+		de->proc_fops = NULL;
+		/* Wait until all existing callers into module are done. */
+		if (de->pde_users > 0) {
+			DECLARE_COMPLETION_ONSTACK(c);
+
+			if (!de->pde_unload_completion)
+				de->pde_unload_completion = &c;
+
+			spin_unlock(&de->pde_unload_lock);
+			spin_unlock(&proc_subdir_lock);
+
+			wait_for_completion(de->pde_unload_completion);
+
+			spin_lock(&proc_subdir_lock);
+			goto continue_removing;
+		}
+		spin_unlock(&de->pde_unload_lock);
+
+continue_removing:
 		if (S_ISDIR(de->mode))
 			parent->nlink--;
-		proc_kill_inodes(de);
+		if (!S_ISREG(de->mode))
+			proc_kill_inodes(de);
 		de->nlink = 0;
 		WARN_ON(de->subdir);
 		if (!atomic_read(&de->count))