84 lines
2.9 KiB
Diff
84 lines
2.9 KiB
Diff
commit c00b984fcd53f679ca2dafcd1aee2c89836e6e73
|
|
Author: Florian Weimer <fweimer@redhat.com>
|
|
Date: Tue Aug 29 08:28:31 2023 +0200
|
|
|
|
nscd: Skip unusable entries in first pass in prune_cache (bug 30800)
|
|
|
|
Previously, if an entry was marked unusable for any reason, but had
|
|
not timed out yet, the assert would trigger.
|
|
|
|
One way to get into such state is if a data change is detected during
|
|
re-validation of an entry. This causes the entry to be marked as not
|
|
usable. If exits nscd soon after that, then the clock jumps
|
|
backwards, and nscd restarted, the cache re-validation run after
|
|
startup triggers the removed assert.
|
|
|
|
The change is more complicated than just the removal of the assert
|
|
because entries marked as not usable should be garbage-collected in
|
|
the second pass. To make this happen, it is necessary to update some
|
|
book-keeping data.
|
|
|
|
Reviewed-by: DJ Delorie <dj@redhat.com>
|
|
|
|
diff --git a/nscd/cache.c b/nscd/cache.c
|
|
index efe4214d953edb30..2fd3f78ebb567bbe 100644
|
|
--- a/nscd/cache.c
|
|
+++ b/nscd/cache.c
|
|
@@ -371,8 +371,11 @@ prune_cache (struct database_dyn *table, time_t now, int fd)
|
|
serv2str[runp->type], str, dh->timeout);
|
|
}
|
|
|
|
- /* Check whether the entry timed out. */
|
|
- if (dh->timeout < now)
|
|
+ /* Check whether the entry timed out. Timed out entries
|
|
+ will be revalidated. For unusable records, it is still
|
|
+ necessary to record that the bucket needs to be scanned
|
|
+ again below. */
|
|
+ if (dh->timeout < now || !dh->usable)
|
|
{
|
|
/* This hash bucket could contain entries which need to
|
|
be looked at. */
|
|
@@ -384,7 +387,7 @@ prune_cache (struct database_dyn *table, time_t now, int fd)
|
|
/* We only have to look at the data of the first entries
|
|
since the count information is kept in the data part
|
|
which is shared. */
|
|
- if (runp->first)
|
|
+ if (runp->first && dh->usable)
|
|
{
|
|
|
|
/* At this point there are two choices: we reload the
|
|
@@ -400,9 +403,6 @@ prune_cache (struct database_dyn *table, time_t now, int fd)
|
|
{
|
|
/* Remove the value. */
|
|
dh->usable = false;
|
|
-
|
|
- /* We definitely have some garbage entries now. */
|
|
- any = true;
|
|
}
|
|
else
|
|
{
|
|
@@ -414,18 +414,15 @@ prune_cache (struct database_dyn *table, time_t now, int fd)
|
|
|
|
time_t timeout = readdfcts[runp->type] (table, runp, dh);
|
|
next_timeout = MIN (next_timeout, timeout);
|
|
-
|
|
- /* If the entry has been replaced, we might need
|
|
- cleanup. */
|
|
- any |= !dh->usable;
|
|
}
|
|
}
|
|
+
|
|
+ /* If the entry has been replaced, we might need cleanup. */
|
|
+ any |= !dh->usable;
|
|
}
|
|
else
|
|
- {
|
|
- assert (dh->usable);
|
|
- next_timeout = MIN (next_timeout, dh->timeout);
|
|
- }
|
|
+ /* Entry has not timed out and is usable. */
|
|
+ next_timeout = MIN (next_timeout, dh->timeout);
|
|
|
|
run = runp->next;
|
|
}
|