#include <linux/fs.h>
#include <linux/backing-file.h>
#include <linux/splice.h>
+#include <linux/mm.h>
#include "internal.h"
}
EXPORT_SYMBOL_GPL(backing_file_splice_write);
+int backing_file_mmap(struct file *file, struct vm_area_struct *vma,
+ struct backing_file_ctx *ctx)
+{
+ const struct cred *old_cred;
+ int ret;
+
+ if (WARN_ON_ONCE(!(file->f_mode & FMODE_BACKING)) ||
+ WARN_ON_ONCE(ctx->user_file != vma->vm_file))
+ return -EIO;
+
+ if (!file->f_op->mmap)
+ return -ENODEV;
+
+ vma_set_file(vma, file);
+
+ old_cred = override_creds(ctx->cred);
+ ret = call_mmap(vma->vm_file, vma);
+ revert_creds(old_cred);
+
+ if (ctx->accessed)
+ ctx->accessed(ctx->user_file);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(backing_file_mmap);
+
static int __init backing_aio_init(void)
{
backing_aio_cachep = kmem_cache_create("backing_aio",
#include <linux/uio.h>
#include <linux/uaccess.h>
#include <linux/security.h>
-#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/backing-file.h>
#include "overlayfs.h"
static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
{
struct file *realfile = file->private_data;
- const struct cred *old_cred;
- int ret;
-
- if (!realfile->f_op->mmap)
- return -ENODEV;
-
- if (WARN_ON(file != vma->vm_file))
- return -EIO;
-
- vma_set_file(vma, realfile);
-
- 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);
+ struct backing_file_ctx ctx = {
+ .cred = ovl_creds(file_inode(file)->i_sb),
+ .user_file = file,
+ .accessed = ovl_file_accessed,
+ };
- return ret;
+ return backing_file_mmap(realfile, vma, &ctx);
}
static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
struct file *out, loff_t *ppos, size_t len,
unsigned int flags,
struct backing_file_ctx *ctx);
+int backing_file_mmap(struct file *file, struct vm_area_struct *vma,
+ struct backing_file_ctx *ctx);
#endif /* _LINUX_BACKING_FILE_H */