CVS commit: src/external/cddl/osnet/dist/uts/common/fs/zfs

["YAMAMOTO Takashi" <yamt%netbsd.org@localhost>]

Module Name:    src
Committed By:   yamt
Date:           Sun Mar 22 13:10:57 UTC 2026

Modified Files:
        src/external/cddl/osnet/dist/uts/common/fs/zfs: zfs_vfsops.c
            zfs_vnops.c zfs_znode.c
        src/external/cddl/osnet/dist/uts/common/fs/zfs/sys: zfs_znode.h

Log Message:
zfs: fix "slow rm" issue

* stop commiting zil in zfs_netbsd_reclaim and other operations
  in vnode reclaim path.

* retire zfs_zget_cleaner/VN_RELE_CLEANER.
  instead, just use normal zfs_zget and vrele_async.

note that these two changes depend on each other:

* zfs_zget_cleaner relies on zil_commit in zfs_netbsd_reclaim to
  ensure that the znode referenced by TX_WRITE itx is always in-core.

* otoh, zfs_zget_clear makes zil_commit in the vnode reclaim path
  possible. that is, zfs_netbsd_reclaim (VOP_RECLAIM) is called with
  the vnode in VS_RECLAIMING state, which would make vcache_vget
  block.
  if the vnode being reclaimed happened to have TX_WRITE itx on the
  zil, it deadlocks.

an alternative would be to make the upper layer (vfs_vnode.c) retain
unlinked vnodes for a while. (a bit longer than the 5 sec txg commit
interval should be enough.) eg. by making zfs_netbsd_inactive report
a_recycle = 0. but i guess it's better to remove
zfs_zget_cleaner/VN_RELE_CLEANER to to keep the code less diverged
from the upstream zfs.

also, this commit makes zfs_umount retry vflush a bit.
it's necessary because, for some reasons, during unmount, zil_close
commits the log, which can load some referenced vnodes back to the
cache. i don't understand why zil_close needs to commit the log
when we are syncing txg for unmount anyway. although it might be
possible to avoid the zil commit at all, probably this change
is less invasive than that. this logic is partly from J. Hannken-Illjes.

PR/59885
https://gnats.netbsd.org/59885
discussed on tech-kern.
https://mail-index.netbsd.org/tech-kern/2026/02/20/msg030817.html


To generate a diff of this commit:
cvs rdiff -u -r1.32 -r1.33 \
    src/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_vfsops.c
cvs rdiff -u -r1.91 -r1.92 \
    src/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_vnops.c
cvs rdiff -u -r1.35 -r1.36 \
    src/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_znode.c
cvs rdiff -u -r1.9 -r1.10 \
    src/external/cddl/osnet/dist/uts/common/fs/zfs/sys/zfs_znode.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.