Re: Plugin structure documentation request

[Alexander Zarochentsev <zam@namesys.com>]

On Wednesday 14 December 2005 12:09, Hans Reiser wrote:
> Peter van Hardenberg wrote:
> >It would be quite excellent if we could have even a one sentence
> > description of all the plugin structures. This structure includes many
> > operations not found in conventional VFS, and many of the calls are not
> > described in any documentation I have found.
> >
> >I must confess I am feeling some frustration at the complete lack of
> >documentation of the project. I have very few complaints about the quality
> > of the code, but despite having spent four months working through file
> > after file I still regularly stumble across areas we have not had an
> > excuse to delve into and have no idea how they work in a general sense or
> > what they do. This kind of documentation does not take particularly long
> > to generate but would save new users of the code many, MANY long hours
> > spent poring over code and tracking function calls through the enormous
> > structure.
> >
> >I know you have heard it from the kernel mailing list before, but now you
> > are hearing it from someone uninvolved in that process. A trivial script
> > reports 93866 lines of code in the reiser4 directory. That's a lot of
> > code to navigate without a map.
> >
> >Having got that off my chest, here is one example of a plugin struct that
> >could use documentation. There are several other examples -- notably the
> >pseudo.c structure which is relatively uncomplicated and the directory
> > plugin which is about as complicated as this example "file" plugin.
> >
> >        [PSEUDO_FILE_PLUGIN_ID] = {
> >                .h = {
> >                        .type_id = REISER4_FILE_PLUGIN_TYPE,
> >                        .id = PSEUDO_FILE_PLUGIN_ID,
> >                        .pops = &file_plugin_ops,
> >                        .label = "pseudo",
> >                        .desc = "pseudo file",
> >                        .linkage = TYPE_SAFE_LIST_LINK_ZERO
> >                },
> >                .open =              open_pseudo,
> >                .truncate          = eperm,
> >                .write_sd_by_inode = eperm,
> >                .readpage          = eperm,
> >                .capturepage       = NULL,
> >                .capture           = NULL,
> >                .read              = read_pseudo,
> >                .write             = write_pseudo,
> >                .release           = release_pseudo,
> >                .ioctl             = eperm,
> >                .mmap              = eperm,
> >                .sync = sync_common,
> >                .get_block         = eperm,
> >                .flow_by_inode     = NULL,
> >                .key_by_inode      = NULL,
> >                .set_plug_in_inode = set_plug_in_inode_common,
> >                .adjust_to_parent  = NULL,
> >                .create            = NULL,
> >                .delete            = eperm,
> >                .add_link          = NULL,
> >                .rem_link          = NULL,
> >                .owns_item         = NULL,
> >                .can_add_link      = cannot,
> >                .can_rem_link      = cannot,
> >                .setattr           = inode_setattr,
> >                .getattr           = getattr_common,
> >                .seek              = seek_pseudo,
> >                .detach            = detach_common,
> >                .bind              = bind_common,
> >                .safelink = NULL,
> >                .estimate = {
> >                        .create = NULL,
> >                        .update = NULL,
> >                        .unlink = NULL
> >                },
> >                .wire = {
> >                         .write = wire_write_pseudo,
> >                         .read  = wire_read_pseudo,
> >                         .get   = wire_get_pseudo,
> >                         .size  = wire_size_pseudo,
> >                         .done  = wire_done_pseudo
> >                 },
> >                .init_inode_data = NULL,
> >                .pre_delete = NULL,
> >                .cut_tree_worker = cut_tree_worker_common,
> >                .destroy_inode = NULL,
> >        },
> >
> >Thanks,
> >-pvh
>
> Zam, vs is releasing a patch today, so can you document this for us?
> Thanks.
>
> Hans

fs/reiser4/plugin/plugin.h:file_plugin structure has comments.

-- 
Alex.