locks: helper functions for delegation breaking
We'll need the same logic for rename and link.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a579923..931f919 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1905,6 +1905,9 @@
extern int current_umask(void);
+extern void ihold(struct inode * inode);
+extern void iput(struct inode *);
+
/* /sys/fs */
extern struct kobject *fs_kobj;
@@ -1972,6 +1975,28 @@
return 0;
}
+static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
+{
+ int ret;
+
+ ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
+ if (ret == -EWOULDBLOCK && delegated_inode) {
+ *delegated_inode = inode;
+ ihold(inode);
+ }
+ return ret;
+}
+
+static inline int break_deleg_wait(struct inode **delegated_inode)
+{
+ int ret;
+
+ ret = break_deleg(*delegated_inode, O_WRONLY);
+ iput(*delegated_inode);
+ *delegated_inode = NULL;
+ return ret;
+}
+
#else /* !CONFIG_FILE_LOCKING */
static inline int locks_mandatory_locked(struct inode *inode)
{
@@ -2015,6 +2040,18 @@
{
return 0;
}
+
+static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
+{
+ return 0;
+}
+
+static inline int break_deleg_wait(struct inode **delegated_inode)
+{
+ BUG();
+ return 0;
+}
+
#endif /* CONFIG_FILE_LOCKING */
/* fs/open.c */
@@ -2350,8 +2387,6 @@
extern int inode_init_always(struct super_block *, struct inode *);
extern void inode_init_once(struct inode *);
extern void address_space_init_once(struct address_space *mapping);
-extern void ihold(struct inode * inode);
-extern void iput(struct inode *);
extern struct inode * igrab(struct inode *);
extern ino_t iunique(struct super_block *, ino_t);
extern int inode_needs_sync(struct inode *inode);