From 254edc8b3b8d67a952919a32e7aea0e1e8c26b78 Mon Sep 17 00:00:00 2001 From: Darren Archibald Date: Wed, 6 Aug 2025 03:29:39 -0700 Subject: [PATCH] server: Fix .zero fallback path When no efficient zero method is supported, we fall back to writing a buffer of actual zeroes. However because of an omitted update to 'offset' we would only zero out (up to) the first 64M of each range. nbdcopy defaults to working on blocks of 128M, leaving the second 64M unzeroed. This affects only backing filesystems which do not support fallocate FALLOC_FL_PUNCH_HOLE or FALLOC_FL_ZERO_RANGE, which turns out to be rare, but it does include some NFS-mounted filesystems which is where I saw this problem. Fixes: commit 19184d3 Thanks: Alex Kalenyuk Signed-off-by: Darren Archibald --- server/plugins.c | 1 + 1 file changed, 1 insertion(+) diff --git a/server/plugins.c b/server/plugins.c index 3c7df0d..db36ce4 100644 --- a/server/plugins.c +++ b/server/plugins.c @@ -807,6 +807,7 @@ plugin_zero (struct context *c, if (r == -1) break; count -= limit; + offset += limit; } done: -- 2.31.1