vfs: export check_sticky()
It's already duplicated in btrfs and about to be used in overlayfs too.
Move the sticky bit check to an inline helper and call the out-of-line
helper only in the unlikly case of the sticky bit being set.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5419df7..55cc0a3 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2259,6 +2259,7 @@
extern int inode_permission(struct inode *, int);
extern int __inode_permission(struct inode *, int);
extern int generic_permission(struct inode *, int);
+extern int __check_sticky(struct inode *dir, struct inode *inode);
static inline bool execute_ok(struct inode *inode)
{
@@ -2745,6 +2746,14 @@
return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
}
+static inline int check_sticky(struct inode *dir, struct inode *inode)
+{
+ if (!(dir->i_mode & S_ISVTX))
+ return 0;
+
+ return __check_sticky(dir, inode);
+}
+
static inline void inode_has_no_xattr(struct inode *inode)
{
if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & MS_NOSEC))