sha512, skein, and edonr have an unenforced dependency on extensible dataset
In any pool without the extensible dataset feature flag already enabled, creating a dataset with dedup set to use one of the new checksums would result in the following panic as soon as any data was added:
panic[cpu0]/thread=ffffff0006761c40: feature_get_refcount(spa, feature, &refcount) != 48 (0x30 != 0x30), file: ../../common/fs/zfs/zfeature.c line 390 ffffff0006761830 fffffffffba8fbdd () ffffff0006761890 zfs:feature_do_action+11a () ffffff00067618c0 zfs:spa_feature_incr+1e () ffffff0006761920 zfs:dmu_object_zapify+b7 () ffffff00067619b0 zfs:dsl_dataset_activate_feature+97 () ffffff0006761a20 zfs:dsl_dataset_sync+ba () ffffff0006761ab0 zfs:dsl_pool_sync+153 () ffffff0006761b70 zfs:spa_sync+26e () ffffff0006761c20 zfs:txg_sync_thread+227 () ffffff0006761c30 unix:thread_start+8 ()
Inspection showed that feature->fi_feature was 7, which is the value of SPA_FEATURE_EXTENSIBLE_DATASET in the spa_feature enum.
Testing shows that the panic can be prevented by explicitly setting extensible dataset as a dependency for the sha512, edonr, and skein feature flags. Alternatively, the new checksums code could possibly be changed to obviate the need for the dependency.
root@omnios-vm:/root# zpool create -d -o feature@sha512=enabled ineedextensibledataset c2t1d0 root@omnios-vm:/root# echo hello >> /ineedextensibledataset/hello.txt root@omnios-vm:/root# zfs create -o dedup=sha512 ineedextensibledataset/ruhroh root@omnios-vm:/root# echo goodbye >> /ineedextensibledataset/ruhroh/goodbye.txt root@omnios-vm:/root# ... panic
Updated by Electric Monk over 4 years ago
- Status changed from In Progress to Closed
- % Done changed from 0 to 100
commit 892586e8a147c02d7f4053cc405229a13e796928 Author: ilovezfs <email@example.com> Date: 2016-02-11T18:22:23.000Z 6585 sha512, skein, and edonr have an unenforced dependency on extensible dataset Reviewed by: Matthew Ahrens <firstname.lastname@example.org> Reviewed by: Richard Laager <email@example.com> Approved by: Robert Mustacchi <firstname.lastname@example.org>