Ingo Weinhold wrote:
On 2009-06-07 at 14:22:24 [+0200], Brecht Machiels <brecht@xxxxxxxxxxx> wrote:However, from my understanding of the documentation, I do not believe publish_vnode should be called in this case (just reading a directory). This seems to be confirmed here: //www.freelists.org/post/haiku-development/Filesystem-API-documentation,4 I would think that the vfs layer should call my get_vnode() in this case. Is this correct? My debug output however does not indicate that this hook is being called.The get_vnode() hook is actually not triggered by POSIX API that often (or at all?). It is called mostly only when your file system requests it -- i.e. you call the VFS's get_vnode() function -- or when via the Be API node_refs or entry_refs are resolved.The more likely hook to be called during directory iteration is lookup(), which resolves the entry in directory to a node. On success it does indeed have to return a new vnode reference, i.e. call the get_vnode() function.
lookup() doesn't get called either. I suspect there is a bug somewhere in the initial setup of the volume or of the root node that is causing this. Userlandfs' debug output should provide more clues, I guess.
Ingo told me to enable debug for the userlandfs module. I added the following to my UserBuildConfig: SetConfigVar DEBUG : HAIKU_TOP src add-ons kernel file_systems userlandfs : 1 : global ; I only seem to get critical warnings in he syslog however. What did I miss?What kind of critical warnings?
Only when I kill the userlandfs_server:KERN: userlandfs [2360672338: 2230] Volume::ReadStat(): connection lost, emulating stat for the root node KERN: userlandfs [2360681262: 2230] Volume::WriteVNode(): connection lost, forcing write vnode
I seem to remember that more debug info was output when I first started messing around with userlandfs, but I'm not sure.
I have tried to find some answers in the available documentation: * the Haiku Book * Practical File System Design by D. Giampaolo * the POSIX specifications on opengroup.org Could the Haiku Book documentation be brought up to date to reflect the recent changes in the fs API?Though not as complete as it could be, it is up to date. The generated Haiku Book on factory.haiku-os.org seems to be an old version, though. Just build a fresh one from the sources. The FS documentation lives in docs/user/drivers/fs_{modules,interface}.dox.
Sorry for not being very clear. I was referring to bringing the version on factory.haiku-os.org up to date. Perhaps that can be done automatically?
I have now finally taken the time to generate the Haiku Book locally. It reads much nicer than the .dox files :)
I also dug in the sources for bfs and some others, but these are still a bit too complicated for me to find my way in.For a less complex and completely virtual FS you can have a look at the rootfs sources in src/system/kernel/fs/rootfs.cpp.
I've taken a quick look at this. It looks like I could grasp what is going on there. Thanks!
Brecht
