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))