From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Thu, 15 Feb 2024 13:46:06 +0000 (+0900)
Subject: journal-file-util: use COPY_VERIFY_LINKED
X-Git-Tag: v256-rc1~835^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=18d4e475c7fad8a5f003e5eb2a9ed0616e0ade20;p=thirdparty%2Fsystemd.git

journal-file-util: use COPY_VERIFY_LINKED

As the main thread may call journal_directory_vacuum() ->
unlinkat_deallocate() while another thread is copying the file.

Fixes #24150 and #31222.
---

diff --git a/src/shared/journal-file-util.c b/src/shared/journal-file-util.c
index b9c44442c31..8df165d2f14 100644
--- a/src/shared/journal-file-util.c
+++ b/src/shared/journal-file-util.c
@@ -210,11 +210,15 @@ static void journal_file_set_offline_internal(JournalFile *f) {
 
                                 log_debug_errno(r, "Failed to re-enable copy-on-write for %s: %m, rewriting file", f->path);
 
+                                /* Here, setting COPY_VERIFY_LINKED flag is crucial. Otherwise, a broken
+                                 * journal file may be created, if journal_directory_vacuum() ->
+                                 * unlinkat_deallocate() is called in the main thread while this thread is
+                                 * copying the file. See issue #24150 and #31222. */
                                 r = copy_file_atomic_at_full(
                                                 f->fd, NULL, AT_FDCWD, f->path, f->mode,
                                                 0,
                                                 FS_NOCOW_FL,
-                                                COPY_REPLACE | COPY_FSYNC | COPY_HOLES | COPY_ALL_XATTRS,
+                                                COPY_REPLACE | COPY_FSYNC | COPY_HOLES | COPY_ALL_XATTRS | COPY_VERIFY_LINKED,
                                                 NULL, NULL);
                                 if (r < 0) {
                                         log_debug_errno(r, "Failed to rewrite %s: %m", f->path);