vfs: add the fadvise() file operation

This is going to be used by overlayfs and possibly useful
for other filesystems.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index ec2142c8dbd3..a6c6a8af48a2 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -885,6 +885,7 @@ struct file_operations {
         ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, loff_t, size_t, unsigned int);
         int (*clone_file_range)(struct file *, loff_t, struct file *, loff_t, u64);
         int (*dedupe_file_range)(struct file *, loff_t, struct file *, loff_t, u64);
+        int (*fadvise)(struct file *, loff_t, loff_t, int);
 };
 
 Again, all methods are called without any locks being held, unless
@@ -965,6 +966,8 @@ otherwise noted.
   dedupe_file_range: called by the ioctl(2) system call for FIDEDUPERANGE
         command.
 
+  fadvise: possibly called by the fadvise64() system call.
+
 Note that the file operations are implemented by the specific
 filesystem in which the inode resides. When opening a device node
 (character or block special) most filesystems will call special