From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Miklos Szeredi To: linux-unionfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 19/39] ovl: add ovl_mmap() Date: Tue, 29 May 2018 16:43:19 +0200 Message-Id: <20180529144339.16538-20-mszeredi@redhat.com> In-Reply-To: <20180529144339.16538-1-mszeredi@redhat.com> References: <20180529144339.16538-1-mszeredi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Implement stacked mmap. Signed-off-by: Miklos Szeredi --- fs/overlayfs/file.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index 7b47dce4b072..4057bbf2e141 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -255,6 +255,33 @@ static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync) return ret; } +static int ovl_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct fd real; + const struct cred *old_cred; + int ret; + + ret = ovl_real_fdget(file, &real); + if (ret) + return ret; + + /* transfer ref: */ + fput(vma->vm_file); + vma->vm_file = get_file(real.file); + fdput(real); + + if (!vma->vm_file->f_op->mmap) + return -ENODEV; + + old_cred = ovl_override_creds(file_inode(file)->i_sb); + ret = call_mmap(vma->vm_file, vma); + revert_creds(old_cred); + + ovl_file_accessed(file); + + return ret; +} + const struct file_operations ovl_file_operations = { .open = ovl_open, .release = ovl_release, @@ -262,4 +289,5 @@ const struct file_operations ovl_file_operations = { .read_iter = ovl_read_iter, .write_iter = ovl_write_iter, .fsync = ovl_fsync, + .mmap = ovl_mmap, }; -- 2.14.3