MFV r306423: 7402 Create tunable to ignore hole_birth feature

Until we can resolve the numerous hole_birth bugs that have cropped up
recently, and come up with a way going forwards to protect users from
corruption, we should disable the hole_birth feature.  Using a tunable
allows those who are confident that their data is correct to continue to
take advantage of the feature.

Closes #188

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Author: Paul Dagnelie <pcd@delphix.com>
This commit is contained in:
Alexander Motin 2016-09-29 00:00:37 +00:00
commit 226a11f81e

View File

@ -40,6 +40,11 @@
#include <sys/zfeature.h>
int32_t zfs_pd_bytes_max = 50 * 1024 * 1024; /* 50MB */
boolean_t send_holes_without_birth_time = B_TRUE;
SYSCTL_DECL(_vfs_zfs);
SYSCTL_UINT(_vfs_zfs, OID_AUTO, send_holes_without_birth_time, CTLFLAG_RWTUN,
&send_holes_without_birth_time, 0, "Send holes without birth time");
typedef struct prefetch_data {
kmutex_t pd_mtx;
@ -254,7 +259,8 @@ traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
*
* Note that the meta-dnode cannot be reallocated.
*/
if ((!td->td_realloc_possible ||
if (!send_holes_without_birth_time &&
(!td->td_realloc_possible ||
zb->zb_object == DMU_META_DNODE_OBJECT) &&
td->td_hole_birth_enabled_txg <= td->td_min_txg)
return (0);