fs: Export generic_fadvise()

mainline inclusion
from mainline-5.4-rc1
commit cf1ea059
category: bugfix
bugzilla: 22583
CVE: NA

---------------------------

Filesystems will need to call this function from their fadvise handlers.

CC: stable@vger.kernel.org
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Nyu kuai <yukuai3@huawei.com>
Reviewed-by: NHou Tao <houtao1@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

include/linux/fs.h

@@ -3516,5 +3516,7 @@ extern void inode_nohighmem(struct inode *inode);
 /* mm/fadvise.c */
 extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len,
 		       int advice);
+extern int generic_fadvise(struct file *file, loff_t offset, loff_t len,
+			   int advice);
 
 #endif /* _LINUX_FS_H */

mm/fadvise.c

@@ -27,7 +27,7 @@
  * deactivate the pages and clear PG_Referenced.
  */
 
-static int generic_fadvise(struct file *file, loff_t offset, loff_t len,
+int generic_fadvise(struct file *file, loff_t offset, loff_t len,
 			   int advice)
 {
 	struct inode *inode;
@@ -178,6 +178,7 @@ static int generic_fadvise(struct file *file, loff_t offset, loff_t len,
 	}
 	return 0;
 }
+EXPORT_SYMBOL(generic_fadvise);
 
 int vfs_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
 {