s3:vfs_fileid: introduce algorithm 'next_module'

This can be use to get just bypass the fileid module for the
common case. But it allows 'fileid:nolockinode' (and in future
other things) to work in order to avoid lock contention
for all 'nolock' inodes.

If we would have started from scratch all the nolock
logic would have been in its own vfs module, just
altering file_id.extid

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>

diff --git a/source3/modules/vfs_fileid.c b/source3/modules/vfs_fileid.c
index 9fe9855f6ce9cb3befa2a8bd38fcf19c1ac80694..7f235aaddb4926378579884576836ce45c5d6d87 100644 (file)
--- a/source3/modules/vfs_fileid.c
+++ b/source3/modules/vfs_fileid.c
@@ -41,6 +41,7 @@ struct fileid_nolock_inode {
 };
 
 struct fileid_handle_data {
+       struct vfs_handle_struct *handle;
        struct file_id (*mapping_fn)(struct fileid_handle_data *data,
                                     const SMB_STRUCT_STAT *sbuf);
        char **fstype_deny_list;
@@ -402,6 +403,12 @@ static struct file_id fileid_mapping_fsid(struct fileid_handle_data *data,
        return id;
 }
 
+static struct file_id fileid_mapping_next_module(struct fileid_handle_data *data,
+                                                const SMB_STRUCT_STAT *sbuf)
+{
+       return SMB_VFS_NEXT_FILE_ID_CREATE(data->handle, sbuf);
+}
+
 static int get_connectpath_ino(struct vfs_handle_struct *handle,
                               const char *path,
                               SMB_STRUCT_STAT *psbuf)
@@ -470,7 +477,7 @@ static int fileid_connect(struct vfs_handle_struct *handle,
                return ret;
        }
 
-       data = talloc_zero(handle->conn, struct fileid_handle_data);
+       data = talloc_zero(handle, struct fileid_handle_data);
        if (!data) {
                saved_errno = errno;
                SMB_VFS_NEXT_DISCONNECT(handle);
@@ -478,6 +485,7 @@ static int fileid_connect(struct vfs_handle_struct *handle,
                errno = saved_errno;
                return -1;
        }
+       data->handle = handle;
 
        /*
         * "fileid:mapping" is only here as fallback for old setups
@@ -503,6 +511,8 @@ static int fileid_connect(struct vfs_handle_struct *handle,
        } else if (strcmp("fsname_norootdir_ext", algorithm) == 0) {
                data->mapping_fn = fileid_mapping_fsname_norootdir_ext;
                rootdir_nolock = true;
+       } else if (strcmp("next_module", algorithm) == 0) {
+               data->mapping_fn        = fileid_mapping_next_module;
        } else {
                SMB_VFS_NEXT_DISCONNECT(handle);
                DEBUG(0,("fileid_connect(): unknown algorithm[%s]\n", algorithm));