mirror_zfs/module
Matthew Ahrens 1a5b96b8ee OpenZFS 9329 - panic in zap_leaf_lookup() due to concurrent zapification
For the null pointer issue shown below, the solution is to initialize the
contents of the object before changing its type, so that concurrent accessors
will see it as non-zapified until it is ready for access via the ZAP.

    BAD TRAP: type=e (#pf Page fault) rp=ffffff00ff520440 addr=20 occurred
    in module "zfs" due to a NULL pointer dereference

    ffffff00ff520320 unix:die+df ()
    ffffff00ff520430 unix:trap+dc0 ()
    ffffff00ff520440 unix:cmntrap+e6 ()
    ffffff00ff520590 zfs:zap_leaf_lookup+46 ()
    ffffff00ff520640 zfs:fzap_lookup+a9 ()
    ffffff00ff5206e0 zfs:zap_lookup_norm+111 ()
    ffffff00ff520730 zfs:zap_contains+42 ()
    ffffff00ff520760 zfs:dsl_dataset_has_resume_receive_state+47 ()
    ffffff00ff520900 zfs:get_receive_resume_stats+3e ()
    ffffff00ff520a90 zfs:dsl_dataset_stats+262 ()
    ffffff00ff520ac0 zfs:dmu_objset_stats+2b ()
    ffffff00ff520b10 zfs:zfs_ioc_objset_stats_impl+64 ()
    ffffff00ff520b60 zfs:zfs_ioc_objset_stats+33 ()
    ffffff00ff520bd0 zfs:zfs_ioc_dataset_list_next+140 ()
    ffffff00ff520c80 zfs:zfsdev_ioctl+4d7 ()
    ffffff00ff520cc0 genunix:cdev_ioctl+39 ()
    ffffff00ff520d10 specfs:spec_ioctl+60 ()
    ffffff00ff520da0 genunix:fop_ioctl+55 ()
    ffffff00ff520ec0 genunix:ioctl+9b ()
    ffffff00ff520f10 unix:brand_sys_sysenter+1c9 ()

Porting Notes:
* DMU_OT_BYTESWAP conditional in zap_lockdir_impl() kept.

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://illumos.org/issues/9329
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/e8e0f97
Closes #7578
2018-05-31 10:53:49 -07:00
..
avl Update build system and packaging 2018-05-29 16:00:33 -07:00
icp Update build system and packaging 2018-05-29 16:00:33 -07:00
lua Update build system and packaging 2018-05-29 16:00:33 -07:00
nvpair Update build system and packaging 2018-05-29 16:00:33 -07:00
spl Update build system and packaging 2018-05-29 16:00:33 -07:00
unicode Update build system and packaging 2018-05-29 16:00:33 -07:00
zcommon Update build system and packaging 2018-05-29 16:00:33 -07:00
zfs OpenZFS 9329 - panic in zap_leaf_lookup() due to concurrent zapification 2018-05-31 10:53:49 -07:00
.gitignore Prepare SPL repo to merge with ZFS repo 2018-05-29 14:51:39 -07:00
Makefile.in Update build system and packaging 2018-05-29 16:00:33 -07:00