[PATCH 36/39] Revert "vfs: do get_write_access() on upper layer of overlayfs"

[Miklos Szeredi]

This reverts commit 4d0c5ba2ff79ef9f5188998b29fd28fcb05f3667.

We now get write access on both overlay and underlying layers so this patch
is no longer needed for correct operation.

Signed-off-by: Miklos Szeredi <mszer...@redhat.com>
---
 fs/locks.c |  3 +--
 fs/open.c  | 15 ++-------------
 2 files changed, 3 insertions(+), 15 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index 62bbe8b31f26..9c0e5f3da66c 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1654,8 +1654,7 @@ check_conflicting_open(const struct dentry *dentry, const 
long arg, int flags)
        if (flags & FL_LAYOUT)
                return 0;
 
-       if ((arg == F_RDLCK) &&
-           (atomic_read(&d_real_inode(dentry)->i_writecount) > 0))
+       if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
                return -EAGAIN;
 
        if ((arg == F_WRLCK) && ((d_count(dentry) > 1) ||
diff --git a/fs/open.c b/fs/open.c
index 127b49819afb..0d63b57c7f89 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -68,7 +68,6 @@ int do_truncate(struct dentry *dentry, loff_t length, 
unsigned int time_attrs,
 long vfs_truncate(const struct path *path, loff_t length)
 {
        struct inode *inode;
-       struct dentry *upperdentry;
        long error;
 
        inode = path->dentry->d_inode;
@@ -91,17 +90,7 @@ long vfs_truncate(const struct path *path, loff_t length)
        if (IS_APPEND(inode))
                goto mnt_drop_write_and_out;
 
-       /*
-        * If this is an overlayfs then do as if opening the file so we get
-        * write access on the upper inode, not on the overlay inode.  For
-        * non-overlay filesystems d_real() is an identity function.
-        */
-       upperdentry = d_real(path->dentry, NULL, O_WRONLY);
-       error = PTR_ERR(upperdentry);
-       if (IS_ERR(upperdentry))
-               goto mnt_drop_write_and_out;
-
-       error = get_write_access(upperdentry->d_inode);
+       error = get_write_access(inode);
        if (error)
                goto mnt_drop_write_and_out;
 
@@ -120,7 +109,7 @@ long vfs_truncate(const struct path *path, loff_t length)
                error = do_truncate(path->dentry, length, 0, NULL);
 
 put_write_and_out:
-       put_write_access(upperdentry->d_inode);
+       put_write_access(inode);
 mnt_drop_write_and_out:
        mnt_drop_write(path->mnt);
 out:
-- 
2.14.3