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

Pull filesystem fixes from Al Viro:
 "Several bugfixes (all of them -stable fodder).

  Alexey's one deals with double mutex_lock() in UFS (apparently, nobody
  has tried to test "ufs: sb mutex merge + mutex_destroy" on something
  like file creation/removal on ufs).  Mine deal with two kinds of
  umount bugs, in umount propagation and in handling of automounted
  submounts, both resulting in bogus transient EBUSY from umount"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ufs: fix deadlocks introduced by sb mutex merge
  fix EBUSY on umount() from MNT_SHRINKABLE
  get rid of propagate_umount() mistakenly treating slaves as busy.

4 files changed, 18 insertions, 14 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index a01c7730e9af..ef42d9bee212 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1217,6 +1217,11 @@ static void namespace_unlock(void)
         head.first->pprev = &head.first;
         INIT_HLIST_HEAD(&unmounted);
 
+        /* undo decrements we'd done in umount_tree() */
+        hlist_for_each_entry(mnt, &head, mnt_hash)
+                if (mnt->mnt_ex_mountpoint.mnt)
+                        mntget(mnt->mnt_ex_mountpoint.mnt);
+
         up_write(&namespace_sem);
 
         synchronize_rcu();
@@ -1253,6 +1258,9 @@ void umount_tree(struct mount *mnt, int how)
                 hlist_add_head(&p->mnt_hash, &tmp_list);
         }
 
+        hlist_for_each_entry(p, &tmp_list, mnt_hash)
+                list_del_init(&p->mnt_child);
+
         if (how)
                 propagate_umount(&tmp_list);
 
@@ -1263,9 +1271,9 @@ void umount_tree(struct mount *mnt, int how)
                 p->mnt_ns = NULL;
                 if (how < 2)
                         p->mnt.mnt_flags |= MNT_SYNC_UMOUNT;
-                list_del_init(&p->mnt_child);
                 if (mnt_has_parent(p)) {
                         put_mountpoint(p->mnt_mp);
+                        mnt_add_count(p->mnt_parent, -1);
                         /* move the reference to mountpoint into ->mnt_ex_mountpoint */
                         p->mnt_ex_mountpoint.dentry = p->mnt_mountpoint;
                         p->mnt_ex_mountpoint.mnt = &p->mnt_parent->mnt;
diff --git a/fs/pnode.c b/fs/pnode.c
index 302bf22c4a30..aae331a5d03b 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -381,6 +381,7 @@ static void __propagate_umount(struct mount *mnt)
                  * other children
                  */
                 if (child && list_empty(&child->mnt_mounts)) {
+                        list_del_init(&child->mnt_child);
                         hlist_del_init_rcu(&child->mnt_hash);
                         hlist_add_before_rcu(&child->mnt_hash, &mnt->mnt_hash);
                 }
diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index 7c580c97990e..be7d42c7d938 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -902,9 +902,6 @@ void ufs_evict_inode(struct inode * inode)
         invalidate_inode_buffers(inode);
         clear_inode(inode);
 
-        if (want_delete) {
-                lock_ufs(inode->i_sb);
-                ufs_free_inode (inode);
-                unlock_ufs(inode->i_sb);
-        }
+        if (want_delete)
+                ufs_free_inode(inode);
 }
diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c
index 90d74b8f8eba..2df62a73f20c 100644
--- a/fs/ufs/namei.c
+++ b/fs/ufs/namei.c
@@ -126,12 +126,12 @@ static int ufs_symlink (struct inode * dir, struct dentry * dentry,
         if (l > sb->s_blocksize)
                 goto out_notlocked;
 
-        lock_ufs(dir->i_sb);
         inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
         err = PTR_ERR(inode);
         if (IS_ERR(inode))
-                goto out;
+                goto out_notlocked;
 
+        lock_ufs(dir->i_sb);
         if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
                 /* slow symlink */
                 inode->i_op = &ufs_symlink_inode_operations;
@@ -181,13 +181,9 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
         struct inode * inode;
         int err;
 
-        lock_ufs(dir->i_sb);
-        inode_inc_link_count(dir);
-
         inode = ufs_new_inode(dir, S_IFDIR|mode);
-        err = PTR_ERR(inode);
         if (IS_ERR(inode))
-                goto out_dir;
+                return PTR_ERR(inode);
 
         inode->i_op = &ufs_dir_inode_operations;
         inode->i_fop = &ufs_dir_operations;
@@ -195,6 +191,9 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
 
         inode_inc_link_count(inode);
 
+        lock_ufs(dir->i_sb);
+        inode_inc_link_count(dir);
+
         err = ufs_make_empty(inode, dir);
         if (err)
                 goto out_fail;
@@ -212,7 +211,6 @@ out_fail:
         inode_dec_link_count(inode);
         inode_dec_link_count(inode);
         iput (inode);
-out_dir:
         inode_dec_link_count(dir);
         unlock_ufs(dir->i_sb);
         goto out;