Better low-memory handling: If the link cache runs out of memory, just

throw out the whole thing and stop tracking links entirely.  That will
break all remaining hardlinks, but should free up enough memory to
let everything finish.

1 files changed, 36 insertions, 35 deletions

diff --git a/usr.bin/tar/write.c b/usr.bin/tar/write.c
index e8d4ca0..3a52248 100644
--- a/usr.bin/tar/write.c
+++ b/usr.bin/tar/write.c
@@ -75,7 +75,6 @@ struct links_cache {
 	unsigned long		  number_entries;
 	size_t			  number_buckets;
 	struct links_entry	**buckets;
-	char			  stop_allocating;
 };
 
 struct links_entry {
@@ -106,6 +105,7 @@ static void		 archive_names_from_file(struct bsdtar *bsdtar,
 static int		 archive_names_from_file_helper(struct bsdtar *bsdtar,
 			     const char *line);
 static void		 create_cleanup(struct bsdtar *);
+static void		 free_buckets(struct bsdtar *, struct links_cache *);
 static void		 free_cache(struct name_cache *cache);
 static const char *	 lookup_gname(struct bsdtar *bsdtar, gid_t gid);
 static int		 lookup_gname_helper(struct bsdtar *bsdtar,
@@ -653,7 +653,7 @@ write_heirarchy(struct bsdtar *bsdtar, struct archive *a, const char *path)
 			 * Skip this file if it's flagged "nodump" and we're
 			 * honoring that flag.
 			 */
-#ifdef HAVE_CHFLAGS
+#if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
 			if (bsdtar->option_honor_nodump &&
 			    (ftsent->fts_statp->st_flags & UF_NODUMP))
 				break;
@@ -885,32 +885,11 @@ write_file_data(struct bsdtar *bsdtar, struct archive *a, int fd)
 
 
 static void
-create_cleanup(struct bsdtar * bsdtar)
+create_cleanup(struct bsdtar *bsdtar)
 {
-	struct links_cache *links_cache;
-	size_t i;
-
-
 	/* Free inode->pathname map used for hardlink detection. */
 	if (bsdtar->links_cache != NULL) {
-		links_cache = bsdtar->links_cache;
-		if (links_cache->buckets != NULL) {
-			for (i = 0; i < links_cache->number_buckets; i++) {
-				while (links_cache->buckets[i] != NULL) {
-					struct links_entry *lp =
-					    links_cache->buckets[i]->next;
-					if (bsdtar->option_warn_links)
-						bsdtar_warnc(bsdtar, 0,
-						    "Missing links to %s",
-						    links_cache->buckets[i]->name);
-					if (links_cache->buckets[i]->name != NULL)
-						free(links_cache->buckets[i]->name);
-					free(links_cache->buckets[i]);
-					links_cache->buckets[i] = lp;
-				}
-			}
-			free(links_cache->buckets);
-		}
+		free_buckets(bsdtar, bsdtar->links_cache);
 		free(bsdtar->links_cache);
 		bsdtar->links_cache = NULL;
 	}
@@ -923,6 +902,30 @@ create_cleanup(struct bsdtar * bsdtar)
 
 
 static void
+free_buckets(struct bsdtar *bsdtar, struct links_cache *links_cache)
+{
+	size_t i;
+
+	if (links_cache->buckets == NULL)
+		return;
+
+	for (i = 0; i < links_cache->number_buckets; i++) {
+		while (links_cache->buckets[i] != NULL) {
+			struct links_entry *lp = links_cache->buckets[i]->next;
+			if (bsdtar->option_warn_links)
+				bsdtar_warnc(bsdtar, 0, "Missing links to %s",
+				    links_cache->buckets[i]->name);
+			if (links_cache->buckets[i]->name != NULL)
+				free(links_cache->buckets[i]->name);
+			free(links_cache->buckets[i]);
+			links_cache->buckets[i] = lp;
+		}
+	}
+	free(links_cache->buckets);
+	links_cache->buckets = NULL;
+}
+
+static void
 lookup_hardlink(struct bsdtar *bsdtar, struct archive_entry *entry,
     const struct stat *st)
 {
@@ -951,9 +954,12 @@ lookup_hardlink(struct bsdtar *bsdtar, struct archive_entry *entry,
 			links_cache->buckets[i] = NULL;
 	}
 
+	/* If the links cache overflowed and got flushed, don't bother. */
+	if (links_cache->buckets == NULL)
+		return;
+
 	/* If the links cache is getting too full, enlarge the hash table. */
-	if (links_cache->number_entries > links_cache->number_buckets * 2 &&
-	    !links_cache->stop_allocating)
+	if (links_cache->number_entries > links_cache->number_buckets * 2)
 	{
 		int count;
 
@@ -986,10 +992,10 @@ lookup_hardlink(struct bsdtar *bsdtar, struct archive_entry *entry,
 			links_cache->buckets = new_buckets;
 			links_cache->number_buckets = new_size;
 		} else {
-			links_cache->stop_allocating = 1;
+			free_buckets(bsdtar, links_cache);
 			bsdtar_warnc(bsdtar, ENOMEM,
 			    "No more memory for recording hard links");
-			bsdtar_warnc(bsdtar, 0, 
+			bsdtar_warnc(bsdtar, 0,
 			    "Remaining links will be dumped as full files");
 		}
 	}
@@ -1023,17 +1029,12 @@ lookup_hardlink(struct bsdtar *bsdtar, struct archive_entry *entry,
 		}
 	}
 
-	if (links_cache->stop_allocating)
-		return;
-
 	/* Add this entry to the links cache. */
 	le = malloc(sizeof(struct links_entry));
 	if (le != NULL)
 		le->name = strdup(archive_entry_pathname(entry));
 	if ((le == NULL) || (le->name == NULL)) {
-		/* TODO: Just flush the entire links cache when we
-		 * run out of memory; don't hold onto anything. */
-		links_cache->stop_allocating = 1;
+		free_buckets(bsdtar, links_cache);
 		bsdtar_warnc(bsdtar, ENOMEM,
 		    "No more memory for recording hard links");
 		bsdtar_warnc(bsdtar, 0,