[PATCH] punch-alternating: prevent punching all extents

[cem@kernel.org]

From: Carlos Maiolino <cem@kernel.org>

If by any chance the punch size is >= the interval, we end up punching
everything, zeroing out the file.

As this is not a tool to dealloc the whole file, so force the user to
pass a configuration that won't cause it to happen.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
---
 src/punch-alternating.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/punch-alternating.c b/src/punch-alternating.c
index d2bb4b6a2276..c555b48d8591 100644
--- a/src/punch-alternating.c
+++ b/src/punch-alternating.c
@@ -88,6 +88,11 @@ int main(int argc, char *argv[])
 		usage(argv[0]);
 	}
 
+	if (size >= interval) {
+		printf("Interval must be > size\n");
+		usage(argv[0]);
+	}
+
 	if (optind != argc - 1)
 		usage(argv[0]);
 
-- 
2.52.0