From: Daan De Meyer <daan.j.demeyer@gmail.com>
Date: Thu, 22 Aug 2024 15:23:58 +0000 (+0200)
Subject: Revert "tree-wide: Don't explicity disable copy-on-write when copying images"
X-Git-Tag: v257-rc1~557^2~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=519216b71fb3c95c0dfbc9b09a4aa4a67179939e;p=thirdparty%2Fsystemd.git

Revert "tree-wide: Don't explicity disable copy-on-write when copying images"

Let's still try to disable COW after copying. It won't do much, but
it doesn't hurt either.

See https://github.com/systemd/systemd/pull/33825/files#r1727288871.

This reverts commit 42e9288180ce37abd86c58774950636ebce35432.
---

diff --git a/src/core/exec-invoke.c b/src/core/exec-invoke.c
index af5552379ef..57f96f7eab5 100644
--- a/src/core/exec-invoke.c
+++ b/src/core/exec-invoke.c
@@ -2891,6 +2891,16 @@ static int setup_ephemeral(
                 if (fd < 0)
                         return log_debug_errno(fd, "Failed to copy image %s to %s: %m",
                                                *root_image, new_root);
+
+                /* A root image might be subject to lots of random writes so let's try to disable COW on it
+                 * which tends to not perform well in combination with lots of random writes.
+                 *
+                 * Note: btrfs actually isn't impressed by us setting the flag after making the reflink'ed
+                 * copy, but we at least want to make the intention clear.
+                 */
+                r = chattr_fd(fd, FS_NOCOW_FL, FS_NOCOW_FL, NULL);
+                if (r < 0)
+                        log_debug_errno(r, "Failed to disable copy-on-write for %s, ignoring: %m", new_root);
         } else {
                 assert(*root_directory);
 
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index 9cd52e06c08..c1820690310 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -6072,8 +6072,10 @@ static int run(int argc, char *argv[]) {
 
                         {
                                 BLOCK_SIGNALS(SIGINT);
-                                r = copy_file(arg_image, np, O_EXCL, arg_read_only ? 0400 : 0600,
-                                              COPY_REFLINK|COPY_CRTIME|COPY_SIGINT);
+                                r = copy_file_full(arg_image, np, O_EXCL, arg_read_only ? 0400 : 0600,
+                                                   FS_NOCOW_FL, FS_NOCOW_FL,
+                                                   COPY_REFLINK|COPY_CRTIME|COPY_SIGINT,
+                                                   NULL, NULL);
                         }
                         if (r == -EINTR) {
                                 log_error_errno(r, "Interrupted while copying image file to %s, removed again.", np);
diff --git a/src/shared/discover-image.c b/src/shared/discover-image.c
index 1386452203f..dd78a013aaf 100644
--- a/src/shared/discover-image.c
+++ b/src/shared/discover-image.c
@@ -1205,7 +1205,8 @@ int image_clone(Image *i, const char *new_name, bool read_only) {
         case IMAGE_RAW:
                 new_path = strjoina("/var/lib/machines/", new_name, ".raw");
 
-                r = copy_file_atomic(i->path, new_path, read_only ? 0444 : 0644, COPY_REFLINK|COPY_CRTIME);
+                r = copy_file_atomic_full(i->path, new_path, read_only ? 0444 : 0644, FS_NOCOW_FL, FS_NOCOW_FL,
+                                          COPY_REFLINK|COPY_CRTIME, NULL, NULL);
                 break;
 
         case IMAGE_BLOCK: