4 files changed, 11 insertions, 41 deletions

diff --git a/fs/file_table.c b/fs/file_table.c
index ee20658a0647..ce1504fec5a1 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -177,43 +177,12 @@ struct file *alloc_file(struct path *path, fmode_t mode,
         file->f_mapping = path->dentry->d_inode->i_mapping;
         file->f_mode = mode;
         file->f_op = fop;
-
-        /*
-         * These mounts don't really matter in practice
-         * for r/o bind mounts.  They aren't userspace-
-         * visible.  We do this for consistency, and so
-         * that we can do debugging checks at __fput()
-         */
-        if ((mode & FMODE_WRITE) && !special_file(path->dentry->d_inode->i_mode)) {
-                WARN_ON(mnt_clone_write(path->mnt));
-        }
         if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
                 i_readcount_inc(path->dentry->d_inode);
         return file;
 }
 EXPORT_SYMBOL(alloc_file);
 
-/**
- * drop_file_write_access - give up ability to write to a file
- * @file: the file to which we will stop writing
- *
- * This is a central place which will give up the ability
- * to write to @file, along with access to write through
- * its vfsmount.
- */
-static void drop_file_write_access(struct file *file)
-{
-        struct vfsmount *mnt = file->f_path.mnt;
-        struct dentry *dentry = file->f_path.dentry;
-        struct inode *inode = dentry->d_inode;
-
-        if (special_file(inode->i_mode))
-                return;
-
-        put_write_access(inode);
-        __mnt_drop_write(mnt);
-}
-
 /* the real guts of fput() - releasing the last reference to file
  */
 static void __fput(struct file *file)
@@ -248,8 +217,10 @@ static void __fput(struct file *file)
         put_pid(file->f_owner.pid);
         if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
                 i_readcount_dec(inode);
-        if (file->f_mode & FMODE_WRITE)
-                drop_file_write_access(file);
+        if (file->f_mode & FMODE_WRITER) {
+                put_write_access(inode);
+                __mnt_drop_write(mnt);
+        }
         file->f_path.dentry = NULL;
         file->f_path.mnt = NULL;
         file->f_inode = NULL;
diff --git a/fs/namespace.c b/fs/namespace.c
index a66aff5bd3fe..20e8696c31a7 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -414,9 +414,7 @@ EXPORT_SYMBOL_GPL(mnt_clone_write);
  */
 int __mnt_want_write_file(struct file *file)
 {
-        struct inode *inode = file_inode(file);
-
-        if (!(file->f_mode & FMODE_WRITE) || special_file(inode->i_mode))
+        if (!(file->f_mode & FMODE_WRITER))
                 return __mnt_want_write(file->f_path.mnt);
         else
                 return mnt_clone_write(file->f_path.mnt);
diff --git a/fs/open.c b/fs/open.c
index ebef0c5fa10c..dcefb2f02d10 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -670,6 +670,7 @@ static int do_dentry_open(struct file *f,
                         put_write_access(inode);
                         goto cleanup_file;
                 }
+                f->f_mode |= FMODE_WRITER;
         }
 
         f->f_mapping = inode->i_mapping;
@@ -715,11 +716,9 @@ static int do_dentry_open(struct file *f,
 
 cleanup_all:
         fops_put(f->f_op);
-        if (f->f_mode & FMODE_WRITE) {
-                if (!special_file(inode->i_mode)) {
-                        put_write_access(inode);
-                        __mnt_drop_write(f->f_path.mnt);
-                }
+        if (f->f_mode & FMODE_WRITER) {
+                put_write_access(inode);
+                __mnt_drop_write(f->f_path.mnt);
         }
 cleanup_file:
         path_put(&f->f_path);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e80659ed78fc..d9d88a0b456e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -125,6 +125,8 @@ typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 
 /* File needs atomic accesses to f_pos */
 #define FMODE_ATOMIC_POS        ((__force fmode_t)0x8000)
+/* Write access to underlying fs */
+#define FMODE_WRITER            ((__force fmode_t)0x10000)
 
 /* File was opened by fanotify and shouldn't generate fanotify events */
 #define FMODE_NONOTIFY          ((__force fmode_t)0x1000000)