nbdkit/SOURCES/0016-file-zero-Document-implicit-order-that-we-will-try-z.patch

40 lines
1.4 KiB
Diff

From 8322b16cd13979f7c872d5ce50517688fc7220bd Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Thu, 1 May 2025 10:30:41 +0100
Subject: [PATCH] file: zero: Document implicit order that we will try zeroing
methods
There's no substantive change here. I just pulled out the test (flags
& NBDKIT_FLAG_MAY_TRIM) into a boolean variable, and documented that
we (will) try zero-with-trim methods first.
(cherry picked from commit 61fc023f235b17f8a19302885d1613dd0a7a3793)
(cherry picked from commit c1984ddcc6497c4446d1bf0e8828d1259852eb74)
---
plugins/file/file.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/plugins/file/file.c b/plugins/file/file.c
index 55941bb8..e5fd864f 100644
--- a/plugins/file/file.c
+++ b/plugins/file/file.c
@@ -893,9 +893,14 @@ static int
file_zero (void *handle, uint32_t count, uint64_t offset, uint32_t flags)
{
struct handle *h __attribute__ ((unused)) = handle;
+ const bool may_trim __attribute__ ((unused)) = flags & NBDKIT_FLAG_MAY_TRIM;
+ /* These alternate zeroing methods are ordered. Methods which can
+ * trim (if may_trim is set) are tried first. Methods which can
+ * only zero are tried last.
+ */
#ifdef FALLOC_FL_PUNCH_HOLE
- if (h->can_punch_hole && (flags & NBDKIT_FLAG_MAY_TRIM)) {
+ if (may_trim && h->can_punch_hole) {
int r;
r = do_fallocate (h->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
--
2.47.1