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authorPaul Dagnelie <[email protected]>2019-06-19 09:48:13 -0700
committerBrian Behlendorf <[email protected]>2019-06-19 09:48:12 -0700
commit30af21b02569ac192f52ce6e6511015f8a8d5729 (patch)
treee5f1091c2d3a6e511bbd2414782e490c18e0f59c /module/zfs/refcount.c
parentc1b5801bb5af0055e5f3d263beaa07026103e212 (diff)
Implement Redacted Send/Receive
Redacted send/receive allows users to send subsets of their data to a target system. One possible use case for this feature is to not transmit sensitive information to a data warehousing, test/dev, or analytics environment. Another is to save space by not replicating unimportant data within a given dataset, for example in backup tools like zrepl. Redacted send/receive is a three-stage process. First, a clone (or clones) is made of the snapshot to be sent to the target. In this clone (or clones), all unnecessary or unwanted data is removed or modified. This clone is then snapshotted to create the "redaction snapshot" (or snapshots). Second, the new zfs redact command is used to create a redaction bookmark. The redaction bookmark stores the list of blocks in a snapshot that were modified by the redaction snapshot(s). Finally, the redaction bookmark is passed as a parameter to zfs send. When sending to the snapshot that was redacted, the redaction bookmark is used to filter out blocks that contain sensitive or unwanted information, and those blocks are not included in the send stream. When sending from the redaction bookmark, the blocks it contains are considered as candidate blocks in addition to those blocks in the destination snapshot that were modified since the creation_txg of the redaction bookmark. This step is necessary to allow the target to rehydrate data in the case where some blocks are accidentally or unnecessarily modified in the redaction snapshot. The changes to bookmarks to enable fast space estimation involve adding deadlists to bookmarks. There is also logic to manage the life cycles of these deadlists. The new size estimation process operates in cases where previously an accurate estimate could not be provided. In those cases, a send is performed where no data blocks are read, reducing the runtime significantly and providing a byte-accurate size estimate. Reviewed-by: Dan Kimmel <[email protected]> Reviewed-by: Matt Ahrens <[email protected]> Reviewed-by: Prashanth Sreenivasa <[email protected]> Reviewed-by: John Kennedy <[email protected]> Reviewed-by: George Wilson <[email protected]> Reviewed-by: Chris Williamson <[email protected]> Reviewed-by: Pavel Zhakarov <[email protected]> Reviewed-by: Sebastien Roy <[email protected]> Reviewed-by: Prakash Surya <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Paul Dagnelie <[email protected]> Closes #7958
Diffstat (limited to 'module/zfs/refcount.c')
-rw-r--r--module/zfs/refcount.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/module/zfs/refcount.c b/module/zfs/refcount.c
index bcaa6d387..89528e6d3 100644
--- a/module/zfs/refcount.c
+++ b/module/zfs/refcount.c
@@ -86,7 +86,7 @@ zfs_refcount_destroy_many(zfs_refcount_t *rc, uint64_t number)
{
reference_t *ref;
- ASSERT(rc->rc_count == number);
+ ASSERT3U(rc->rc_count, ==, number);
while ((ref = list_head(&rc->rc_list))) {
list_remove(&rc->rc_list, ref);
kmem_cache_free(reference_cache, ref);
@@ -132,7 +132,7 @@ zfs_refcount_add_many(zfs_refcount_t *rc, uint64_t number, void *holder)
ref->ref_number = number;
}
mutex_enter(&rc->rc_mtx);
- ASSERT(rc->rc_count >= 0);
+ ASSERT3U(rc->rc_count, >=, 0);
if (rc->rc_tracked)
list_insert_head(&rc->rc_list, ref);
rc->rc_count += number;
@@ -155,7 +155,7 @@ zfs_refcount_remove_many(zfs_refcount_t *rc, uint64_t number, void *holder)
int64_t count;
mutex_enter(&rc->rc_mtx);
- ASSERT(rc->rc_count >= number);
+ ASSERT3U(rc->rc_count, >=, number);
if (!rc->rc_tracked) {
rc->rc_count -= number;