Merge tag 'kvmarm-for-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm...

[linux.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index bd2f4c68506afb79023c4423abebe392397c53ea..725d6935fab9f8fb7d80d225b9af52331c702b34 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -430,75 +430,21 @@ int __mnt_want_write_file(struct file *file)
                return mnt_clone_write(file->f_path.mnt);
 }
 
-/**
- * mnt_want_write_file_path - get write access to a file's mount
- * @file: the file who's mount on which to take a write
- *
- * This is like mnt_want_write, but it takes a file and can
- * do some optimisations if the file is open for write already
- *
- * Called by the vfs for cases when we have an open file at hand, but will do an
- * inode operation on it (important distinction for files opened on overlayfs,
- * since the file operations will come from the real underlying file, while
- * inode operations come from the overlay).
- */
-int mnt_want_write_file_path(struct file *file)
-{
-       int ret;
-
-       sb_start_write(file->f_path.mnt->mnt_sb);
-       ret = __mnt_want_write_file(file);
-       if (ret)
-               sb_end_write(file->f_path.mnt->mnt_sb);
-       return ret;
-}
-
-static inline int may_write_real(struct file *file)
-{
-       struct dentry *dentry = file->f_path.dentry;
-       struct dentry *upperdentry;
-
-       /* Writable file? */
-       if (file->f_mode & FMODE_WRITER)
-               return 0;
-
-       /* Not overlayfs? */
-       if (likely(!(dentry->d_flags & DCACHE_OP_REAL)))
-               return 0;
-
-       /* File refers to upper, writable layer? */
-       upperdentry = d_real(dentry, NULL, 0, D_REAL_UPPER);
-       if (upperdentry &&
-           (file_inode(file) == d_inode(upperdentry) ||
-            file_inode(file) == d_inode(dentry)))
-               return 0;
-
-       /* Lower layer: can't write to real file, sorry... */
-       return -EPERM;
-}
-
 /**
  * mnt_want_write_file - get write access to a file's mount
  * @file: the file who's mount on which to take a write
  *
  * This is like mnt_want_write, but it takes a file and can
  * do some optimisations if the file is open for write already
- *
- * Mostly called by filesystems from their ioctl operation before performing
- * modification.  On overlayfs this needs to check if the file is on a read-only
- * lower layer and deny access in that case.
  */
 int mnt_want_write_file(struct file *file)
 {
        int ret;
 
-       ret = may_write_real(file);
-       if (!ret) {
-               sb_start_write(file_inode(file)->i_sb);
-               ret = __mnt_want_write_file(file);
-               if (ret)
-                       sb_end_write(file_inode(file)->i_sb);
-       }
+       sb_start_write(file_inode(file)->i_sb);
+       ret = __mnt_want_write_file(file);
+       if (ret)
+               sb_end_write(file_inode(file)->i_sb);
        return ret;
 }
 EXPORT_SYMBOL_GPL(mnt_want_write_file);
@@ -538,14 +484,9 @@ void __mnt_drop_write_file(struct file *file)
        __mnt_drop_write(file->f_path.mnt);
 }
 
-void mnt_drop_write_file_path(struct file *file)
-{
-       mnt_drop_write(file->f_path.mnt);
-}
-
 void mnt_drop_write_file(struct file *file)
 {
-       __mnt_drop_write(file->f_path.mnt);
+       __mnt_drop_write_file(file);
        sb_end_write(file_inode(file)->i_sb);
 }
 EXPORT_SYMBOL(mnt_drop_write_file);