Re: [Libguestfs] [libnbd PATCH v4 18/25] examples: Update copy-libev to use 64-bit block status

Although our use of "base:allocation" doesn't require the use of the 64-bit API for flags, we might perform slightly faster for a server that does give us 64-bit extent lengths and honors larger nbd_zero lengths. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; Reviewed-by: Richard W.M. Jones <rjones(a)redhat.com&gt; --- v4: no change --- examples/copy-libev.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/examples/copy-libev.c b/examples/copy-libev.c index 32cb46b3..9346faf7 100644 --- a/examples/copy-libev.c +++ b/examples/copy-libev.c @@ -96,7 +96,7 @@ struct request { }; struct extent { - uint32_t length; + uint64_t length; bool zero; }; @@ -184,7 +184,7 @@ get_events (struct connection *c) static int extent_callback (void *user_data, const char *metacontext, uint64_t offset, - uint32_t *entries, size_t nr_entries, int *error) + nbd_extent *entries, size_t nr_entries, int *error) { struct request *r = user_data; @@ -199,22 +199,21 @@ extent_callback (void *user_data, const char *metacontext, uint64_t offset, return 1; } - /* Libnbd returns uint32_t pair (length, flags) for each extent. */ - extents_len = nr_entries / 2; + extents_len = nr_entries; extents = malloc (extents_len * sizeof *extents); if (extents == NULL) FAIL ("Cannot allocated extents: %s", strerror (errno)); /* Copy libnbd entries to extents array. */ - for (int i = 0, j = 0; i < extents_len; i++, j=i*2) { - extents[i].length = entries[j]; + for (int i = 0; i < extents_len; i++) { + extents[i].length = entries[i].length; /* Libnbd exposes both ZERO and HOLE flags. We care only about * ZERO status, meaning we can copy this extent using efficinet * zero method. */ - extents[i].zero = (entries[j + 1] & LIBNBD_STATE_ZERO) != 0; + extents[i].zero = (entries[i].flags & LIBNBD_STATE_ZERO) != 0; } DEBUG ("r%zu: received %zu extents for %s", @@ -286,10 +285,10 @@ start_extents (struct request *r) DEBUG ("r%zu: start extents offset=%" PRIi64 " count=%zu", r->index, offset, count); - cookie = nbd_aio_block_status ( + cookie = nbd_aio_block_status_64 ( src.nbd, count, offset, - (nbd_extent_callback) { .callback=extent_callback, - .user_data=r }, + (nbd_extent64_callback) { .callback=extent_callback, + .user_data=r }, (nbd_completion_callback) { .callback=extents_completed, .user_data=r }, 0); @@ -324,7 +323,7 @@ next_extent (struct request *r) limit = MIN (REQUEST_SIZE, size - offset); while (length < limit) { - DEBUG ("e%zu: offset=%" PRIi64 " len=%" PRIu32 " zero=%d", + DEBUG ("e%zu: offset=%" PRIi64 " len=%" PRIu64 " zero=%d", extents_pos, offset, extents[extents_pos].length, is_zero); /* If this extent is too large, steal some data from it to