--- wikisrc/users/haad/Attic/porting_zfs.mdwn	2009/10/26 23:19:05	1.6
+++ wikisrc/users/haad/Attic/porting_zfs.mdwn	2012/04/06 11:42:15	1.14
@@ -2,12 +2,12 @@
  
 NetBSD zfs port is work in progress and can easily panic your system.
 
-**ZFS currently works ony on i386!!**
+**ZFS currently works ony on i386 and amd64!!**
 
 ---
 # 2. Using NetBSD ZFS port 
 
-## Instalation 
+## Installation 
 
 Use any -current build from i386 or amd64 architecture. All tools and modules should be built by default, now. There are 2 modules used for ZFS solaris.kmod and zfs.kmod. Solaris module provides solaris like interfaces to zfs on NetBSD. The second module is zfs and provides zfs file system functions.
 
@@ -29,7 +29,7 @@ where type is:
 * raidz2
 * default is normal linear allocation
 
-device is blod device on netbsd /dev/sd0a for example.
+device is blod device on NetBSD /dev/sd0a for example.
 
     zpool create tank mirror /dev/sd0a /dev/sd1a  creates mirrored zpool between 2 disk partitions.
 
@@ -55,43 +55,28 @@ After creating ZVOLS and filesystem they
 ## Show stoppers 
 
 ### amd64
-* amd64 zio_root crash
-Investigation 
-vdev_label_read_config -> zio_root calls zio_wait on a zio_root zio_t. Later zio_execute tries to generate 			
-checksum on zio->zio_data which is NULL for a zio_root. Is this ressurrection of andys zio_null problem ? 
-because zio_root is basicaly zio_null.
-		
- Solution
- What is difference between i386 and amd64 version why it is working on i386 and not on a amd64 that can be
- solution.
+
 ### i386 
 
 ### Both 
 * vnode reclaiming deadlocks 
- 
- This can be fixed by deferring call to zfs_zinactive in zfs_reclaim to another system thread if lock is held.
- But it causes deadlock and we need to investigate if it is caused by this change or by another problem.
-			
- Deadlock backtrace is this
-			
- VOP_WRITE->zfs_netbsd_write->zfs_write->dmu_tx_wait->txg_wait_open->cv_wait
- txq_quisce_thread->txg_thread_wait->cv_wait
- txg_sync_thread->spa_sync->dsl_pool_sync->zio_wait->cv_wait
-			
- FreeBSD approach should be investigated why they are doing this differently and why it works for them. They 
- call zfs_zinactive from zfs_freebsd_inactive which is null op for NetBSD.
-			
- zfs umount panic is caused by using FreeBSD approach in zfs_reclaim.
 
+Current code is quite a hack but it works until I will find some time to rework vnode reclaiming on NetBSD.
+
+http://nxr.netbsd.org/xref/src/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_vnops.c#4254
+ 
 * vnode fsync bug 
   
   I think that we are hitting this bug, too. I have some patches in the tree which fixes deadlod in vnode reclaim but after that I'm getting another deadlock in VOP_FSYNC.
 
+* kmem_cache_alloc/ aka pool_cache_get panicsdue to KM_NOSLEEP flag
+ There are some problems in the NetBSD UVM subsytem when KM_NOSLEEP allocation can fail even if system has enough memory to use. I talked with ad@ about it and he said that there is one problem in uvm where some lock is held, KM_NOSLEEP allocation will fail.
+
 ## Functional bugs 
 * Snapshots
 * Permissions
 * Old code, we should update NetBSD zfs port to new code
-* More tasks can be found at [http://nxr.netbsd.org/xref/src/external/cddl/osnet/TODO]
+* More tasks can be found at <http://nxr.netbsd.org/xref/src/external/cddl/osnet/TODO>
 
 # External Documentation links
-Nice zfs howto written for zfs + mac os x [http://code.google.com/p/maczfs/wiki/GettingStarted]
+Nice zfs howto written for zfs + mac os x <http://code.google.com/p/maczfs/wiki/GettingStarted>