If the ZAP object containing a snapshot map is corrupted due to an
unrecoverable checksum error or otherwise, dsl_dataset_name() will
normally panic the system due to its VERIFY.
This patch attempts to allow a recovery avenue from such situations by
manufacturing a descriptive snapshot name and then ignoring the error.
Scrubbing a pool with this type of corruption will then show the affected
object in the error list rather than panicking.
The recovery code is only enabled when the zfs_recover module parameter
is set.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3705
headphys = headdbuf->db_data;
err = zap_value_search(dp->dp_meta_objset,
headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
+ if (err != 0 && zfs_recover == B_TRUE) {
+ err = 0;
+ (void) snprintf(ds->ds_snapname, sizeof (ds->ds_snapname),
+ "SNAPOBJ=%llu-ERR=%d",
+ (unsigned long long)ds->ds_object, err);
+ }
dmu_buf_rele(headdbuf, FTAG);
return (err);
}