During pool export flush the ARC asynchronously

This also includes removing L2 vdevs asynchronously.

This commit also guarantees that spa_load_guid is unique.

The zpool reguid feature introduced the spa_load_guid, which is a
transient value used for runtime identification purposes in the ARC.
This value is not the same as the spa's persistent pool guid.

However, the value is seeded from spa_generate_load_guid() which
does not check for uniqueness against the spa_load_guid from other
pools.  Although extremely rare, you can end up with two different
pools sharing the same spa_load_guid value! So we guarantee that
the value is always unique and additionally not still in use by an
async arc flush task.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Don Brady <don.brady@klarasystems.com>
Closes #16215
This commit is contained in:
Don Brady
2024-12-05 09:58:20 -07:00
committed by GitHub
parent 2507db612d
commit 44446dccdb
7 changed files with 341 additions and 82 deletions
+4 -4
View File
@@ -378,8 +378,8 @@ typedef struct l2arc_lb_ptr_buf {
* L2ARC Internals
*/
typedef struct l2arc_dev {
vdev_t *l2ad_vdev; /* vdev */
spa_t *l2ad_spa; /* spa */
vdev_t *l2ad_vdev; /* can be NULL during remove */
spa_t *l2ad_spa; /* can be NULL during remove */
uint64_t l2ad_hand; /* next write location */
uint64_t l2ad_start; /* first addr on device */
uint64_t l2ad_end; /* last addr on device */
@@ -475,8 +475,8 @@ struct arc_buf_hdr {
arc_buf_contents_t b_type;
uint8_t b_complevel;
uint8_t b_reserved1; /* used for 4 byte alignment */
uint16_t b_reserved2; /* used for 4 byte alignment */
uint8_t b_reserved1; /* used for 4 byte alignment */
uint16_t b_l2size; /* alignment or L2-only size */
arc_buf_hdr_t *b_hash_next;
arc_flags_t b_flags;