From 1b07a798de79d62b0fe28af2a667069408e4f904 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Vavru=C5=A1a?= <marek.vavrusa@nic.cz>
Date: Mon, 1 Dec 2014 23:46:09 +0100
Subject: [PATCH] journal: correct file end position detection
This fixes an issue where the journal file could grow over the set
limit if:
1. Last entry on previous rollover did not fill the file fully
2. The information about the difference between the last entry and the
file size is lost
In such case, the end of file is detected later, leading to
increase of the file size by the size of the first evicted entries.
---
src/knot/server/journal.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)
diff --git a/src/knot/server/journal.c b/src/knot/server/journal.c
index 2c1e873a76..37ea0829d5 100644
--- a/src/knot/server/journal.c
+++ b/src/knot/server/journal.c
@@ -483,10 +483,10 @@ int journal_write_in(journal_t *j, journal_node_t **rn, uint64_t id, size_t len)
dbg_journal("journal: will write id=%llu, node=%u, size=%zu, fsize=%zu\n",
(unsigned long long)id, j->qtail, len, j->fsize);
- /* Calculate remaining bytes to reach file size limit. */
- size_t fs_remaining = 0;
- if (j->fsize < j->fslimit) {
- fs_remaining = j->fslimit - j->fsize;
+ /* Calculate file end position (with imposed limits). */
+ size_t file_end = j->fsize;
+ if (file_end > j->fslimit) {
+ file_end = j->fslimit;
}
int seek_ret = 0;
@@ -495,12 +495,12 @@ int journal_write_in(journal_t *j, journal_node_t **rn, uint64_t id, size_t len)
dbg_journal("journal: free.pos = %u free.len = %u\n",
j->free.pos, j->free.len);
journal_node_t *n = j->nodes + j->qtail;
- if (j->free.pos + j->free.len == j->fsize) {
+ if (j->free.pos + len >= file_end) {
dbg_journal_verb("journal: * is last node\n");
/* Grow journal file until the size limit. */
- if(j->free.len < len && len <= fs_remaining) {
+ if(j->free.pos + len < j->fslimit) {
size_t diff = len - j->free.len;
dbg_journal("journal: * growing by +%zu, pos=%u, "
"new fsize=%zu\n",
@@ -509,10 +509,8 @@ int journal_write_in(journal_t *j, journal_node_t **rn, uint64_t id, size_t len)
j->fsize += diff; /* Appending increases file size. */
j->free.len += diff;
- }
-
- /* Rewind if resize is needed, but the limit is reached. */
- if(j->free.len < len && len > fs_remaining) {
+ } else {
+ /* Rewind if resize is needed, but the limit is reached. */
journal_node_t *head = j->nodes + j->qhead;
j->fsize = j->free.pos;
j->free.pos = head->pos;
--
GitLab