Merge branch 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs RCU symlink updates from Al Viro:
 "Replacement of ->follow_link/->put_link, allowing to stay in RCU mode
  even if the symlink is not an embedded one.

  No changes since the mailbomb on Jan 1"

* 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch ->get_link() to delayed_call, kill ->put_link()
  kill free_page_put_link()
  teach nfs_get_link() to work in RCU mode
  teach proc_self_get_link()/proc_thread_self_get_link() to work in RCU mode
  teach shmem_get_link() to work in RCU mode
  teach page_get_link() to work in RCU mode
  replace ->follow_link() with new method that could stay in RCU mode
  don't put symlink bodies in pagecache into highmem
  namei: page_getlink() and page_follow_link_light() are the same thing
  ufs: get rid of ->setattr() for symlinks
  udf: don't duplicate page_symlink_inode_operations
  logfs: don't duplicate page_symlink_inode_operations
  switch befs long symlinks to page_symlink_operations

3 files changed, 44 insertions, 7 deletions

diff --git a/include/linux/delayed_call.h b/include/linux/delayed_call.h
new file mode 100644
index 000000000000..f7fa76ae1a9b
--- /dev/null
+++ b/include/linux/delayed_call.h
@@ -0,0 +1,34 @@
+#ifndef _DELAYED_CALL_H
+#define _DELAYED_CALL_H
+
+/*
+ * Poor man's closures; I wish we could've done them sanely polymorphic,
+ * but...
+ */
+
+struct delayed_call {
+	void (*fn)(void *);
+	void *arg;
+};
+
+#define DEFINE_DELAYED_CALL(name) struct delayed_call name = {NULL, NULL}
+
+/* I really wish we had closures with sane typechecking... */
+static inline void set_delayed_call(struct delayed_call *call,
+		void (*fn)(void *), void *arg)
+{
+	call->fn = fn;
+	call->arg = arg;
+}
+
+static inline void do_delayed_call(struct delayed_call *call)
+{
+	if (call->fn)
+		call->fn(call->arg);
+}
+
+static inline void clear_delayed_call(struct delayed_call *call)
+{
+	call->fn = NULL;
+}
+#endif
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 51f9f8d93d4d..ef3cd36689f6 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -31,6 +31,7 @@
 #include <linux/blk_types.h>
 #include <linux/workqueue.h>
 #include <linux/percpu-rwsem.h>
+#include <linux/delayed_call.h>
 
 #include <asm/byteorder.h>
 #include <uapi/linux/fs.h>
@@ -1633,12 +1634,11 @@ struct file_operations {
 
 struct inode_operations {
 	struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
-	const char * (*follow_link) (struct dentry *, void **);
+	const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);
 	int (*permission) (struct inode *, int);
 	struct posix_acl * (*get_acl)(struct inode *, int);
 
 	int (*readlink) (struct dentry *, char __user *,int);
-	void (*put_link) (struct inode *, void *);
 
 	int (*create) (struct inode *,struct dentry *, umode_t, bool);
 	int (*link) (struct dentry *,struct inode *,struct dentry *);
@@ -2736,14 +2736,14 @@ extern const struct file_operations generic_ro_fops;
 
 extern int readlink_copy(char __user *, int, const char *);
 extern int page_readlink(struct dentry *, char __user *, int);
-extern const char *page_follow_link_light(struct dentry *, void **);
-extern void page_put_link(struct inode *, void *);
+extern const char *page_get_link(struct dentry *, struct inode *,
+				 struct delayed_call *);
+extern void page_put_link(void *);
 extern int __page_symlink(struct inode *inode, const char *symname, int len,
 		int nofs);
 extern int page_symlink(struct inode *inode, const char *symname, int len);
 extern const struct inode_operations page_symlink_inode_operations;
-extern void kfree_put_link(struct inode *, void *);
-extern void free_page_put_link(struct inode *, void *);
+extern void kfree_link(void *);
 extern int generic_readlink(struct dentry *, char __user *, int);
 extern void generic_fillattr(struct inode *, struct kstat *);
 int vfs_getattr_nosec(struct path *path, struct kstat *stat);
@@ -2754,7 +2754,8 @@ void __inode_sub_bytes(struct inode *inode, loff_t bytes);
 void inode_sub_bytes(struct inode *inode, loff_t bytes);
 loff_t inode_get_bytes(struct inode *inode);
 void inode_set_bytes(struct inode *inode, loff_t bytes);
-const char *simple_follow_link(struct dentry *, void **);
+const char *simple_get_link(struct dentry *, struct inode *,
+			    struct delayed_call *);
 extern const struct inode_operations simple_symlink_inode_operations;
 
 extern int iterate_dir(struct file *, struct dir_context *);
@@ -3023,5 +3024,6 @@ static inline bool dir_relax(struct inode *inode)
 }
 
 extern bool path_noexec(const struct path *path);
+extern void inode_nohighmem(struct inode *inode);
 
 #endif /* _LINUX_FS_H */
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index c0e961474a52..37a3d2981352 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -359,6 +359,7 @@ extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode);
 extern int nfs_revalidate_inode_rcu(struct nfs_server *server, struct inode *inode);
 extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
 extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
+extern int nfs_revalidate_mapping_rcu(struct inode *inode);
 extern int nfs_revalidate_mapping_protected(struct inode *inode, struct address_space *mapping);
 extern int nfs_setattr(struct dentry *, struct iattr *);
 extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *);