[RFC PATCH 4/5] fs: export rw_verify_area()

[Omar Sandoval <osandov@osandov.com>]

From: Omar Sandoval <osandov@fb.com>

I'm adding a Btrfs ioctl to write compressed data, and rather than
duplicating the checks in rw_verify_area(), let's just export it.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 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 315fcd8d237c..94e1831d4c95 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -160,11 +160,6 @@ 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 1f5088dec566..9d95491ce9ab 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -399,6 +399,7 @@ 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 997a530ff4e9..a9a1884768e4 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3082,6 +3082,7 @@ extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
 		int whence, loff_t size);
 extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t);
 extern loff_t no_seek_end_llseek(struct file *, loff_t, int);
+extern int rw_verify_area(int, struct file *, const loff_t *, size_t);
 extern int generic_file_open(struct inode * inode, struct file * filp);
 extern int nonseekable_open(struct inode * inode, struct file * filp);
 extern int stream_open(struct inode * inode, struct file * filp);
-- 
2.17.1