Attachment 1473241 Details for Bug 1609128 – Patch - fix update_negative_cache() map source usage (update 2)

[patch] Patch - fix update_negative_cache() map source usage (update 2)

autofs-5.1.4-fix-update_negative_cache-map-source-usage.patch (text/plain), 2.89 KB, created by Ian Kent on 2018-08-04 01:10:08 UTC

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Creator: Ian Kent

Created: 2018-08-04 01:10:08 UTC

Size: 2.89 KB

patch

obsolete

>autofs-5.1.4 - fix update_negative_cache() map source usage
>
>From: Ian Kent <raven@themaw.net>
>
>File map sources can be either plain text or executable.
>
>When the map path is specified without a type (eg. when a
>full path is used) an instance map source is used and the
>original map is left unchanged.
>
>But update_negative_cache() fails to take this into account
>causing it to update the wrong map cache.
>
>When a map reload is done the map entry appears to not exist
>so the new map entry is added.
>
>This could go unnoticed except that, after a map read, the
>map entry cache cleans stale map entries and the existence
>of this negative entry causes the new map entry to be deleted
>and map lookups continue to fail.
>
>In hindsite the use of an instance map source for this is
>probably uneccessary but changing it will be risky so, for
>now, just make update_negative_cache() use the correct map.
>
>Signed-off-by: Ian Kent <raven@themaw.net>
>---
> CHANGELOG       |    1 +
> daemon/lookup.c |   38 ++++++++++++++++++++++++++++++++++++--
> 2 files changed, 37 insertions(+), 2 deletions(-)
>
>--- autofs-5.0.7.orig/CHANGELOG
>+++ autofs-5.0.7/CHANGELOG
>@@ -301,6 +301,7 @@
> - add man page note about extra slashes in paths.
> - add units After line to include statd service.
> - use systemd sd_notify() at startup.
>+- fix update_negative_cache() map source usage.
> 
> 25/07/2012 autofs-5.0.7
> =======================
>--- autofs-5.0.7.orig/daemon/lookup.c
>+++ autofs-5.0.7/daemon/lookup.c
>@@ -1097,6 +1097,37 @@ static enum nsswitch_status lookup_map_n
> 	return result;
> }
> 
>+static struct map_source *lookup_get_map_source(struct master_mapent *entry)
>+{
>+	struct map_source *map = entry->maps;
>+	struct stat st;
>+	char *type;
>+
>+	if (map->type || *map->argv[0] != '/')
>+		return map;
>+
>+	if (*(map->argv[0] + 1) == '/')
>+		return map;
>+
>+	if (stat(map->argv[0], &st) == -1)
>+		return NULL;
>+
>+	if (!S_ISREG(st.st_mode))
>+		return NULL;
>+
>+	if (st.st_mode & __S_IEXEC)
>+		type = "program";
>+	else
>+		type = "file";
>+
>+	/* This is a file source with a path starting with "/".
>+	 * But file maps can be either plain text or executable
>+	 * so they use a map instance and the actual map source
>+	 * remains untouched.
>+	 */
>+	return master_find_source_instance(map, type, map->format, 0, NULL);
>+}
>+
> static void update_negative_cache(struct autofs_point *ap, struct map_source *source, const char *name)
> {
> 	struct master_mapent *entry = ap->entry;
>@@ -1130,11 +1161,14 @@ static void update_negative_cache(struct
> 			logmsg("key \"%s\" not found in map source(s).", name);
> 		}
> 
>-		/* Doesn't exist in any source, just add it somewhere */
>+		/* Doesn't exist in any source, just add it somewhere.
>+		 * Also take care to use the same map source used by
>+		 * map reads and key lookups for the update.
>+		 */
> 		if (source)
> 			map = source;
> 		else
>-			map = entry->maps;
>+			map = lookup_get_map_source(entry);
> 		if (map) {
> 			time_t now = time(NULL);
> 			int rv = CHE_FAIL;

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Attachments on bug 1609128: 1472003 | 1472214 | 1473241