Implement bookmark copying

This feature allows copying existing bookmarks using

    zfs bookmark fs#target fs#newbookmark

There are some niche use cases for such functionality,
e.g. when using bookmarks as markers for replication progress.

Copying redaction bookmarks produces a normal bookmark that
cannot be used for redacted send (we are not duplicating
the redaction object).

ZCP support for bookmarking (both creation and copying) will be
implemented in a separate patch based on this work.

Overview:

- Terminology:
    - source = existing snapshot or bookmark
    - new/bmark = new bookmark
- Implement bookmark copying in `dsl_bookmark.c`
  - create new bookmark node
  - copy source's `zbn_phys` to new's `zbn_phys`
  - zero-out redaction object id in copy
- Extend existing bookmark ioctl nvlist schema to accept
  bookmarks as sources
  - => `dsl_bookmark_create_nvl_validate` is authoritative
- use `dsl_dataset_is_before` check for both snapshot
  and bookmark sources
- Adjust CLI
  - refactor shortname expansion logic in `zfs_do_bookmark`
- Update man pages
  - warn about redaction bookmark handling
- Add test cases
  - CLI
  - pyyzfs libzfs_core bindings

Reviewed-by: Matt Ahrens <[email protected]>
Reviewed-by: Paul Dagnelie <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Christian Schwarz <[email protected]>
Closes #9571

1 files changed, 1 insertions, 0 deletions

diff --git a/include/sys/dsl_bookmark.h b/include/sys/dsl_bookmark.h
index 7e4b8f02f..ec3895d40 100644
--- a/include/sys/dsl_bookmark.h
+++ b/include/sys/dsl_bookmark.h
@@ -103,6 +103,7 @@ typedef struct redact_block_phys {
 typedef int (*rl_traverse_callback_t)(redact_block_phys_t *, void *);
 
 int dsl_bookmark_create(nvlist_t *, nvlist_t *);
+int dsl_bookmark_create_nvl_validate(nvlist_t *);
 int dsl_bookmark_create_redacted(const char *, const char *, uint64_t,
     uint64_t *, void *, redaction_list_t **);
 int dsl_get_bookmarks(const char *, nvlist_t *, nvlist_t *);