From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 3 Apr 2025 12:59:13 +0000 (+0200)
Subject: journal-upload-journal: handle partially written fields gracefully
X-Git-Tag: v258-rc1~633^2~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cf2d660f2f8fcc8f3fb212524fd6a7dfba7bc527;p=thirdparty%2Fsystemd.git

journal-upload-journal: handle partially written fields gracefully

With the more efficient sync semantics it's more likely that
journal-upload-journal will try to read a partially written message.
Previously we'd fail then. Let's instead treat this gracefully,
expecting that this is either the end or will be fixed shortly (and
we'll get notified via inotify about it and recheck).
---

diff --git a/src/journal-remote/journal-upload-journal.c b/src/journal-remote/journal-upload-journal.c
index c910c224246..2967318663b 100644
--- a/src/journal-remote/journal-upload-journal.c
+++ b/src/journal-remote/journal-upload-journal.c
@@ -28,6 +28,11 @@ static ssize_t write_entry(char *buf, size_t size, Uploader *u) {
                         u->current_cursor = mfree(u->current_cursor);
 
                         r = sd_journal_get_cursor(u->journal, &u->current_cursor);
+                        if (r == -EBADMSG) {
+                                log_debug("Encountered bad or partially written entry while acquiring cursor, leaving.");
+                                u->entry_state = ENTRY_OUTRO;
+                                continue;
+                        }
                         if (r < 0)
                                 return log_error_errno(r, "Failed to get cursor: %m");
 
@@ -53,6 +58,11 @@ static ssize_t write_entry(char *buf, size_t size, Uploader *u) {
                         usec_t realtime;
 
                         r = sd_journal_get_realtime_usec(u->journal, &realtime);
+                        if (r == -EBADMSG) {
+                                log_debug("Encountered bad or partially written realtime timestamp, leaving.");
+                                u->entry_state = ENTRY_OUTRO;
+                                continue;
+                        }
                         if (r < 0)
                                 return log_error_errno(r, "Failed to get realtime timestamp: %m");
 
@@ -79,6 +89,11 @@ static ssize_t write_entry(char *buf, size_t size, Uploader *u) {
                         sd_id128_t boot_id;
 
                         r = sd_journal_get_monotonic_usec(u->journal, &monotonic, &boot_id);
+                        if (r == -EBADMSG) {
+                                log_debug("Encountered bad or partially written monotonic timestamp, leaving.");
+                                u->entry_state = ENTRY_OUTRO;
+                                continue;
+                        }
                         if (r < 0)
                                 return log_error_errno(r, "Failed to get monotonic timestamp: %m");
 
@@ -103,7 +118,12 @@ static ssize_t write_entry(char *buf, size_t size, Uploader *u) {
                 case ENTRY_BOOT_ID: {
                         sd_id128_t boot_id;
 
-                        r = sd_journal_get_monotonic_usec(u->journal, NULL, &boot_id);
+                        r = sd_journal_get_monotonic_usec(u->journal, /* ret_monotonic= */ NULL, &boot_id);
+                        if (r == -EBADMSG) {
+                                log_debug("Encountered bad or partially written boot ID, leaving.");
+                                u->entry_state = ENTRY_OUTRO;
+                                continue;
+                        }
                         if (r < 0)
                                 return log_error_errno(r, "Failed to get monotonic timestamp: %m");
 
@@ -131,6 +151,11 @@ static ssize_t write_entry(char *buf, size_t size, Uploader *u) {
                         r = sd_journal_enumerate_data(u->journal,
                                                       &u->field_data,
                                                       &u->field_length);
+                        if (r == -EBADMSG) {
+                                log_debug("Encountered bad or partially written data field, leaving.");
+                                u->entry_state = ENTRY_OUTRO;
+                                continue;
+                        }
                         if (r < 0)
                                 return log_error_errno(r, "Failed to move to next field in entry: %m");
                         if (r == 0) {
@@ -182,9 +207,11 @@ static ssize_t write_entry(char *buf, size_t size, Uploader *u) {
                         size_t len;
 
                         c = memchr(u->field_data, '=', u->field_length);
-                        if (!c || c == u->field_data)
-                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                                       "Invalid field.");
+                        if (!c || c == u->field_data) {
+                                log_debug("Encountered field without '='. Assuming field is still being written, leaving.");
+                                u->entry_state = ENTRY_OUTRO;
+                                continue;
+                        }
 
                         len = c - (const char*)u->field_data;
 
@@ -198,8 +225,9 @@ static ssize_t write_entry(char *buf, size_t size, Uploader *u) {
 
                         u->field_pos = len + 1;
                         u->entry_state++;
-                }
+
                         _fallthrough_;
+                }
                 case ENTRY_BINARY_FIELD_SIZE: {
                         uint64_t le64;
 
@@ -274,10 +302,7 @@ static size_t journal_input_callback(void *buf, size_t size, size_t nmemb, void
         while (j && filled < size * nmemb) {
                 if (u->entry_state == ENTRY_DONE) {
                         r = sd_journal_next(j);
-                        if (r < 0) {
-                                log_error_errno(r, "Failed to move to next entry in journal: %m");
-                                return CURL_READFUNC_ABORT;
-                        } else if (r == 0) {
+                        if (r == 0) {
                                 if (u->input_event)
                                         log_debug("No more entries, waiting for journal.");
                                 else {
@@ -286,10 +311,23 @@ static size_t journal_input_callback(void *buf, size_t size, size_t nmemb, void
                                 }
 
                                 u->uploading = false;
-
                                 break;
                         }
+                        if (r == -EBADMSG) {
+                                if (u->input_event)
+                                        log_debug("Read bad or partially written entry, waiting for journal.");
+                                else {
+                                        log_info("Read bad or partially written entry, waiting for journal.");
+                                        close_journal_input(u);
+                                }
 
+                                u->uploading = false;
+                                break;
+                        }
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to move to next entry in journal: %m");
+                                return CURL_READFUNC_ABORT;
+                        }
                         u->entry_state = ENTRY_CURSOR;
                 }