Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs fixes from Al Viro:
 "A nasty bug in fs/namespace.c caught by Andrey + a couple of less
  serious unpleasantness - ecryptfs misc device playing hopeless games
  with try_module_get() and palinfo procfs support being...  not quite
  correctly done, to be polite."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  mnt: release locks on error path in do_loopback
  palinfo fixes
  procfs: add proc_remove_subtree()
  ecryptfs: close rmmod race

3 files changed, 92 insertions, 43 deletions

diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c
index 412e6eda25f8..e4141f257495 100644
--- a/fs/ecryptfs/miscdev.c
+++ b/fs/ecryptfs/miscdev.c
@@ -80,13 +80,6 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
         int rc;
 
         mutex_lock(&ecryptfs_daemon_hash_mux);
-        rc = try_module_get(THIS_MODULE);
-        if (rc == 0) {
-                rc = -EIO;
-                printk(KERN_ERR "%s: Error attempting to increment module use "
-                       "count; rc = [%d]\n", __func__, rc);
-                goto out_unlock_daemon_list;
-        }
         rc = ecryptfs_find_daemon_by_euid(&daemon);
         if (!rc) {
                 rc = -EINVAL;
@@ -96,7 +89,7 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
         if (rc) {
                 printk(KERN_ERR "%s: Error attempting to spawn daemon; "
                        "rc = [%d]\n", __func__, rc);
-                goto out_module_put_unlock_daemon_list;
+                goto out_unlock_daemon_list;
         }
         mutex_lock(&daemon->mux);
         if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) {
@@ -108,9 +101,6 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
         atomic_inc(&ecryptfs_num_miscdev_opens);
 out_unlock_daemon:
         mutex_unlock(&daemon->mux);
-out_module_put_unlock_daemon_list:
-        if (rc)
-                module_put(THIS_MODULE);
 out_unlock_daemon_list:
         mutex_unlock(&ecryptfs_daemon_hash_mux);
         return rc;
@@ -147,7 +137,6 @@ ecryptfs_miscdev_release(struct inode *inode, struct file *file)
                        "bug.\n", __func__, rc);
                 BUG();
         }
-        module_put(THIS_MODULE);
         return rc;
 }
 
@@ -471,6 +460,7 @@ out_free:
 
 
 static const struct file_operations ecryptfs_miscdev_fops = {
+        .owner   = THIS_MODULE,
         .open    = ecryptfs_miscdev_open,
         .poll    = ecryptfs_miscdev_poll,
         .read    = ecryptfs_miscdev_read,
diff --git a/fs/namespace.c b/fs/namespace.c
index d581e45c0a9f..341d3f564082 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1690,7 +1690,7 @@ static int do_loopback(struct path *path, const char *old_name,
 
         if (IS_ERR(mnt)) {
                 err = PTR_ERR(mnt);
-                goto out;
+                goto out2;
         }
 
         err = graft_tree(mnt, path);
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 4b3b3ffb52f1..21e1a8f1659d 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -755,37 +755,8 @@ void pde_put(struct proc_dir_entry *pde)
                 free_proc_entry(pde);
 }
 
-/*
- * Remove a /proc entry and free it if it's not currently in use.
- */
-void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
+static void entry_rundown(struct proc_dir_entry *de)
 {
-        struct proc_dir_entry **p;
-        struct proc_dir_entry *de = NULL;
-        const char *fn = name;
-        unsigned int len;
-
-        spin_lock(&proc_subdir_lock);
-        if (__xlate_proc_name(name, &parent, &fn) != 0) {
-                spin_unlock(&proc_subdir_lock);
-                return;
-        }
-        len = strlen(fn);
-
-        for (p = &parent->subdir; *p; p=&(*p)->next ) {
-                if (proc_match(len, fn, *p)) {
-                        de = *p;
-                        *p = de->next;
-                        de->next = NULL;
-                        break;
-                }
-        }
-        spin_unlock(&proc_subdir_lock);
-        if (!de) {
-                WARN(1, "name '%s'\n", name);
-                return;
-        }
-
         spin_lock(&de->pde_unload_lock);
         /*
          * Stop accepting new callers into module. If you're
@@ -817,6 +788,40 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
                 spin_lock(&de->pde_unload_lock);
         }
         spin_unlock(&de->pde_unload_lock);
+}
+
+/*
+ * Remove a /proc entry and free it if it's not currently in use.
+ */
+void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
+{
+        struct proc_dir_entry **p;
+        struct proc_dir_entry *de = NULL;
+        const char *fn = name;
+        unsigned int len;
+
+        spin_lock(&proc_subdir_lock);
+        if (__xlate_proc_name(name, &parent, &fn) != 0) {
+                spin_unlock(&proc_subdir_lock);
+                return;
+        }
+        len = strlen(fn);
+
+        for (p = &parent->subdir; *p; p=&(*p)->next ) {
+                if (proc_match(len, fn, *p)) {
+                        de = *p;
+                        *p = de->next;
+                        de->next = NULL;
+                        break;
+                }
+        }
+        spin_unlock(&proc_subdir_lock);
+        if (!de) {
+                WARN(1, "name '%s'\n", name);
+                return;
+        }
+
+        entry_rundown(de);
 
         if (S_ISDIR(de->mode))
                 parent->nlink--;
@@ -827,3 +832,57 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
         pde_put(de);
 }
 EXPORT_SYMBOL(remove_proc_entry);
+
+int remove_proc_subtree(const char *name, struct proc_dir_entry *parent)
+{
+        struct proc_dir_entry **p;
+        struct proc_dir_entry *root = NULL, *de, *next;
+        const char *fn = name;
+        unsigned int len;
+
+        spin_lock(&proc_subdir_lock);
+        if (__xlate_proc_name(name, &parent, &fn) != 0) {
+                spin_unlock(&proc_subdir_lock);
+                return -ENOENT;
+        }
+        len = strlen(fn);
+
+        for (p = &parent->subdir; *p; p=&(*p)->next ) {
+                if (proc_match(len, fn, *p)) {
+                        root = *p;
+                        *p = root->next;
+                        root->next = NULL;
+                        break;
+                }
+        }
+        if (!root) {
+                spin_unlock(&proc_subdir_lock);
+                return -ENOENT;
+        }
+        de = root;
+        while (1) {
+                next = de->subdir;
+                if (next) {
+                        de->subdir = next->next;
+                        next->next = NULL;
+                        de = next;
+                        continue;
+                }
+                spin_unlock(&proc_subdir_lock);
+
+                entry_rundown(de);
+                next = de->parent;
+                if (S_ISDIR(de->mode))
+                        next->nlink--;
+                de->nlink = 0;
+                if (de == root)
+                        break;
+                pde_put(de);
+
+                spin_lock(&proc_subdir_lock);
+                de = next;
+        }
+        pde_put(root);
+        return 0;
+}
+EXPORT_SYMBOL(remove_proc_subtree);