Infer the right value for nopenfd, and recover from EMFILE.

2 files changed, 34 insertions, 3 deletions

diff --git a/bfs.c b/bfs.c
index fcd1383..6bbfa05 100644
--- a/bfs.c
+++ b/bfs.c
@@ -15,8 +15,27 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/resource.h>
 #include <unistd.h>
 
+static int infer_nopenfd() {
+	int ret = 4096;
+
+	struct rlimit rl;
+	if (getrlimit(RLIMIT_NOFILE, &rl) == 0) {
+		if (rl.rlim_cur != RLIM_INFINITY) {
+			ret = rl.rlim_cur;
+		}
+	}
+
+	// Account for std{in,out,err}
+	if (ret > 3) {
+		ret -= 3;
+	}
+
+	return ret;
+}
+
 typedef struct {
 	const char *path;
 	color_table *colors;
@@ -85,8 +104,8 @@ int main(int argc, char *argv[]) {
 		opts.colors = parse_colors(getenv("LS_COLORS"));
 	}
 
-	// TODO: getrlimit(RLIMIT_NOFILE)
-	if (bftw(opts.path, callback, 1024, flags, &opts) != 0) {
+	int nopenfd = infer_nopenfd();
+	if (bftw(opts.path, callback, nopenfd, flags, &opts) != 0) {
 		perror("bftw()");
 		goto done;
 	}
diff --git a/bftw.c b/bftw.c
index 31e6fe2..75a208c 100644
--- a/bftw.c
+++ b/bftw.c
@@ -291,7 +291,19 @@ static DIR *dircache_entry_open(dircache *cache, dircache_entry *entry, const ch
 		fd = dirfd(base->dir);
 	}
 
-	DIR *dir = opendirat(fd, path + nameoff);
+	const char *relpath = path + nameoff;
+	DIR *dir = opendirat(fd, relpath);
+
+	if (!dir
+	    && errno == EMFILE
+	    && cache->lru_tail
+	    && cache->lru_tail != base) {
+		// Too many open files, shrink the LRU cache
+		dircache_entry_close(cache, cache->lru_tail);
+		--cache->lru_remaining;
+		dir = opendirat(fd, relpath);
+	}
+
 	if (dir) {
 		entry->dir = dir;
 		dircache_lru_add(cache, entry);