fs: name case update method
smpfs and ncpfs want to update a live dentry name in-place. Rather than
have them open code the locking, provide a documented dcache API.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index d6e6453..e80ea4e 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -611,35 +611,12 @@
shrink_dcache_parent(newdent);
/*
- * It is not as dangerous as it looks. NetWare's OS2 namespace is
- * case preserving yet case insensitive. So we update dentry's name
- * as received from server. We found dentry via d_lookup with our
- * hash, so we know that hash does not change, and so replacing name
- * should be reasonably safe.
+ * NetWare's OS2 namespace is case preserving yet case
+ * insensitive. So we update dentry's name as received from
+ * server. Parent dir's i_mutex is locked because we're in
+ * readdir.
*/
- if (qname.len == newdent->d_name.len &&
- memcmp(newdent->d_name.name, qname.name, newdent->d_name.len)) {
- struct inode *inode = newdent->d_inode;
-
- /*
- * Inside ncpfs all uses of d_name are either for debugging,
- * or on functions which acquire inode mutex (mknod, creat,
- * lookup). So grab i_mutex here, to be sure. d_path
- * uses dcache_lock when generating path, so we should too.
- * And finally d_compare is protected by dentry's d_lock, so
- * here we go.
- */
- if (inode)
- mutex_lock(&inode->i_mutex);
- spin_lock(&dcache_lock);
- spin_lock(&newdent->d_lock);
- memcpy((char *) newdent->d_name.name, qname.name,
- newdent->d_name.len);
- spin_unlock(&newdent->d_lock);
- spin_unlock(&dcache_lock);
- if (inode)
- mutex_unlock(&inode->i_mutex);
- }
+ dentry_update_name_case(newdent, &qname);
}
if (!newdent->d_inode) {
@@ -657,7 +634,7 @@
} else {
struct inode *inode = newdent->d_inode;
- mutex_lock(&inode->i_mutex);
+ mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
ncp_update_inode2(inode, entry);
mutex_unlock(&inode->i_mutex);
}
