mirror_zfs/include
Matthew Ahrens 0fdd6106bb
dmu_objset_from_ds must be called with dp_config_rwlock held
The normal lock order is that the dp_config_rwlock must be held before
the ds_opening_lock.  For example, dmu_objset_hold() does this.
However, dmu_objset_open_impl() is called with the ds_opening_lock held,
and if the dp_config_rwlock is not already held, it will attempt to
acquire it.  This may lead to deadlock, since the lock order is
reversed.

Looking at all the callers of dmu_objset_open_impl() (which is
principally the callers of dmu_objset_from_ds()), almost all callers
already have the dp_config_rwlock.  However, there are a few places in
the send and receive code paths that do not.  For example:
dsl_crypto_populate_key_nvlist, send_cb, dmu_recv_stream,
receive_write_byref, redact_traverse_thread.

This commit resolves the problem by requiring all callers ot
dmu_objset_from_ds() to hold the dp_config_rwlock.  In most cases, the
code has been restructured such that we call dmu_objset_from_ds()
earlier on in the send and receive processes, when we already have the
dp_config_rwlock, and save the objset_t until we need it in the middle
of the send or receive (similar to what we already do with the
dsl_dataset_t).  Thus we do not need to acquire the dp_config_rwlock in
many new places.

I also cleaned up code in dmu_redact_snap() and send_traverse_thread().

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Zuchowski <pzuchowski@datto.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #9662
Closes #10115
2020-03-12 10:55:02 -07:00
..
os Improve performance of zio_taskq_member 2020-03-03 10:29:38 -08:00
sys dmu_objset_from_ds must be called with dp_config_rwlock held 2020-03-12 10:55:02 -07:00
.gitignore OpenZFS restructuring - move platform specific sources 2019-09-06 11:26:26 -07:00
libnvpair.h Add JSON output support to channel programs 2018-03-19 12:40:58 -07:00
libuutil_common.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
libuutil_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
libuutil.h Correct cppcheck errors 2017-09-19 12:17:29 -07:00
libzfs_core.h Add 'zfs send --saved' flag 2020-01-10 10:16:58 -08:00
libzfs_impl.h Add FreeBSD jail support hooks 2019-12-11 11:58:37 -08:00
libzfs.h Add trim support to zpool wait 2020-03-04 15:07:11 -08:00
libzutil.h Colorize zpool status output 2019-12-19 16:26:07 -08:00
Makefile.am OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -07:00
thread_pool.h Add libtpool (thread pools) 2017-08-09 15:31:08 -07:00
zfeature_common.h Disable EDONR on FreeBSD 2019-12-05 13:10:29 -08:00
zfs_comutil.h Fix "zpool add -n" for dedup, special and log devices 2020-01-06 15:40:06 -08:00
zfs_deleg.h Remove code for zfs remap 2019-06-24 16:44:01 -07:00
zfs_fletcher.h Add AVX512BW variant of fletcher 2019-10-30 12:26:14 -07:00
zfs_namecheck.h Implement bookmark copying 2020-02-11 13:19:12 -08:00
zfs_prop.h Add zfs module feature and property info to sysfs 2018-09-02 12:09:53 -07:00