proc: fix proc_kill_inodes to kill dentries on all proc superblocks

It appears we overlooked support for removing generic proc files
when we added support for multiple proc super blocks.  Handle
that now.

[akpm@linux-foundation.org: coding-style cleanups]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 25 insertions, 18 deletions

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 1bdb62435758..a9806bc21ec3 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -561,28 +561,33 @@ static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp
 static void proc_kill_inodes(struct proc_dir_entry *de)
 {
         struct list_head *p;
-        struct super_block *sb = proc_mnt->mnt_sb;
+        struct super_block *sb;
 
         /*
          * Actually it's a partial revoke().
          */
-        file_list_lock();
-        list_for_each(p, &sb->s_files) {
-                struct file * filp = list_entry(p, struct file, f_u.fu_list);
-                struct dentry * dentry = filp->f_path.dentry;
-                struct inode * inode;
-                const struct file_operations *fops;
-
-                if (dentry->d_op != &proc_dentry_operations)
-                        continue;
-                inode = dentry->d_inode;
-                if (PDE(inode) != de)
-                        continue;
-                fops = filp->f_op;
-                filp->f_op = NULL;
-                fops_put(fops);
+        spin_lock(&sb_lock);
+        list_for_each_entry(sb, &proc_fs_type.fs_supers, s_instances) {
+                file_list_lock();
+                list_for_each(p, &sb->s_files) {
+                        struct file *filp = list_entry(p, struct file,
+                                                        f_u.fu_list);
+                        struct dentry *dentry = filp->f_path.dentry;
+                        struct inode *inode;
+                        const struct file_operations *fops;
+
+                        if (dentry->d_op != &proc_dentry_operations)
+                                continue;
+                        inode = dentry->d_inode;
+                        if (PDE(inode) != de)
+                                continue;
+                        fops = filp->f_op;
+                        filp->f_op = NULL;
+                        fops_put(fops);
+                }
+                file_list_unlock();
         }
-        file_list_unlock();
+        spin_unlock(&sb_lock);
 }
 
 static struct proc_dir_entry *proc_create(struct proc_dir_entry **parent,
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 1820eb2ef762..1b2b6c6bb475 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -78,3 +78,5 @@ static inline int proc_fd(struct inode *inode)
 {
         return PROC_I(inode)->fd;
 }
+
+extern struct file_system_type proc_fs_type;
diff --git a/fs/proc/root.c b/fs/proc/root.c
index ec9cb3b6c93b..1f86bb860e04 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -98,7 +98,7 @@ static void proc_kill_sb(struct super_block *sb)
         put_pid_ns(ns);
 }
 
-static struct file_system_type proc_fs_type = {
+struct file_system_type proc_fs_type = {
         .name           = "proc",
         .get_sb         = proc_get_sb,
         .kill_sb        = proc_kill_sb,