[RFC PATCH 21/76] vfs: Export rw_verify_area() for use by cachefiles

[David Howells <dhowells@xxxxxxxxxx>]

Export rw_verify_area() for so that cachefiles can use it before issuing
call_read_iter() and call_write_iter() to effect async DIO operations
against the cache.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

 fs/internal.h      |    5 -----
 fs/read_write.c    |    1 +
 include/linux/fs.h |    1 +
 3 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/internal.h b/fs/internal.h
index a7cd0f64faa4..0a536f21f498 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -165,11 +165,6 @@ extern char *simple_dname(struct dentry *, char *, int);
 extern void dput_to_list(struct dentry *, struct list_head *);
 extern void shrink_dentry_list(struct list_head *);
 
-/*
- * read_write.c
- */
-extern int rw_verify_area(int, struct file *, const loff_t *, size_t);
-
 /*
  * pipe.c
  */
diff --git a/fs/read_write.c b/fs/read_write.c
index 75f764b43418..fe84e11245bd 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -400,6 +400,7 @@ int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t
 	return security_file_permission(file,
 				read_write == READ ? MAY_READ : MAY_WRITE);
 }
+EXPORT_SYMBOL(rw_verify_area);
 
 static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
 {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8667d0cdc71e..52fb357579c8 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2762,6 +2762,7 @@ extern int notify_change(struct dentry *, struct iattr *, struct inode **);
 extern int inode_permission(struct inode *, int);
 extern int generic_permission(struct inode *, int);
 extern int __check_sticky(struct inode *dir, struct inode *inode);
+extern int rw_verify_area(int, struct file *, const loff_t *, size_t);
 
 static inline bool execute_ok(struct inode *inode)
 {