From 0c10a1e984bc2bed1fe3a7dadbd94a9c24139a91 Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@tavianator.com>
Date: Tue, 11 Apr 2023 22:06:42 -0400
Subject: dir: Add a flag to bfs_freedir() to force the fd to stay the same

---
 src/bftw.c |  4 ++--
 src/dir.c  | 18 +++++++++++++-----
 src/dir.h  | 10 ++++++++--
 src/ioq.c  |  1 +
 4 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/bftw.c b/src/bftw.c
index 916a56b..a3e8d9b 100644
--- a/src/bftw.c
+++ b/src/bftw.c
@@ -853,13 +853,13 @@ static int bftw_gc(struct bftw_state *state, enum bftw_gc_flags flags) {
 
 		if (file->refcount > 1) {
 			// Keep the fd around if any subdirectories exist
-			file->fd = bfs_freedir(state->dir);
+			file->fd = bfs_freedir(state->dir, false);
 		} else {
-			bfs_closedir(state->dir);
 			file->fd = -1;
 		}
 
 		if (file->fd < 0) {
+			bfs_closedir(state->dir);
 			bftw_cache_remove(&state->cache, file);
 		}
 	}
diff --git a/src/dir.c b/src/dir.c
index 01d26db..126f473 100644
--- a/src/dir.c
+++ b/src/dir.c
@@ -243,13 +243,15 @@ int bfs_closedir(struct bfs_dir *dir) {
 	int ret = xclose(dir->fd);
 #else
 	int ret = closedir(dir->dir);
-	bfs_verify(ret == 0 || errno != EBADF);
+	if (ret != 0) {
+		bfs_verify(errno != EBADF);
+	}
 #endif
 	free(dir);
 	return ret;
 }
 
-int bfs_freedir(struct bfs_dir *dir) {
+int bfs_freedir(struct bfs_dir *dir, bool same_fd) {
 #if BFS_GETDENTS
 	int ret = dir->fd;
 	free(dir);
@@ -257,10 +259,16 @@ int bfs_freedir(struct bfs_dir *dir) {
 	int ret = fdclosedir(dir->dir);
 	free(dir);
 #else
+	if (same_fd) {
+		errno = ENOTSUP;
+		return -1;
+	}
+
 	int ret = dup_cloexec(dirfd(dir->dir));
-	int error = errno;
-	bfs_closedir(dir);
-	errno = error;
+	if (ret >= 0) {
+		bfs_closedir(dir);
+	}
 #endif
+
 	return ret;
 }
diff --git a/src/dir.h b/src/dir.h
index 01eaaba..e0fe913 100644
--- a/src/dir.h
+++ b/src/dir.h
@@ -8,6 +8,7 @@
 #ifndef BFS_DIR_H
 #define BFS_DIR_H
 
+#include "config.h"
 #include <sys/types.h>
 
 /**
@@ -103,9 +104,14 @@ int bfs_closedir(struct bfs_dir *dir);
  *
  * @param dir
  *         The directory to free.
+ * @param same_fd
+ *         If true, require that the returned file descriptor is the same one
+ *         that bfs_dirfd() would have returned.  Otherwise, it may be a new
+ *         file descriptor for the same directory.
  * @return
- *         The file descriptor on success, or -1 on failure.
+ *         On success, a file descriptor for the directory is returned.  On
+ *         failure, -1 is returned, and the directory remains open.
  */
-int bfs_freedir(struct bfs_dir *dir);
+int bfs_freedir(struct bfs_dir *dir, bool same_fd);
 
 #endif // BFS_DIR_H
diff --git a/src/ioq.c b/src/ioq.c
index e09c2a9..1b61fb0 100644
--- a/src/ioq.c
+++ b/src/ioq.c
@@ -155,6 +155,7 @@ static void *ioq_work(void *ptr) {
 		sanitize_uninit(cmd);
 
 		struct ioq_res *res = &cmd->res;
+		res->ptr = req.ptr;
 		res->dir = bfs_opendir(req.dfd, req.path);
 		res->error = errno;
 		ioqq_push(ioq->ready, cmd);
-- 
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