get rid of 'parent' argument of ->d_compare()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 9 insertions, 2 deletions

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 1b3c39a7de62..d30fb2cb5066 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -12,7 +12,7 @@ prototypes:
         int (*d_revalidate)(struct dentry *, unsigned int);
         int (*d_weak_revalidate)(struct dentry *, unsigned int);
         int (*d_hash)(const struct dentry *, struct qstr *);
-        int (*d_compare)(const struct dentry *, const struct dentry *,
+        int (*d_compare)(const struct dentry *,
                         unsigned int, const char *, const struct qstr *);
         int (*d_delete)(struct dentry *);
         int (*d_init)(struct dentry *);
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index a5fb89cac615..b1bd05ea66b2 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -585,3 +585,10 @@ in your dentry operations instead.
         in the instances.  Rationale: !@#!@# security_d_instantiate() needs to be
         called before we attach dentry to inode and !@#!@##!@$!$#!@#$!@$!@$ smack
         ->d_instantiate() uses not just ->getxattr() but ->setxattr() as well.
+--
+[mandatory]
+        ->d_compare() doesn't get parent as a separate argument anymore.  If you
+        used it for finding the struct super_block involved, dentry->d_sb will
+        work just as well; if it's something more complicated, use dentry->d_parent.
+        Just be careful not to assume that fetching it more than once will yield
+        the same value - in RCU mode it could change under you.
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 8a196851f01d..9ace359d6cc5 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -931,7 +931,7 @@ struct dentry_operations {
         int (*d_revalidate)(struct dentry *, unsigned int);
         int (*d_weak_revalidate)(struct dentry *, unsigned int);
         int (*d_hash)(const struct dentry *, struct qstr *);
-        int (*d_compare)(const struct dentry *, const struct dentry *,
+        int (*d_compare)(const struct dentry *,
                         unsigned int, const char *, const struct qstr *);
         int (*d_delete)(const struct dentry *);
         int (*d_init)(struct dentry *);