dir: Arena-allocate directories

6 files changed, 110 insertions, 51 deletions

diff --git a/src/bftw.c b/src/bftw.c
index d0491e0..69e41a2 100644
--- a/src/bftw.c
+++ b/src/bftw.c
@@ -103,6 +103,8 @@ struct bftw_cache {
 
 	/** bftw_file arena. */
 	struct varena files;
+	/** bfs_dir arena. */
+	struct arena dirs;
 };
 
 /** Initialize a cache. */
@@ -111,6 +113,7 @@ static void bftw_cache_init(struct bftw_cache *cache, size_t capacity) {
 	cache->target = NULL;
 	cache->capacity = capacity;
 	VARENA_INIT(&cache->files, struct bftw_file, name);
+	bfs_dir_arena(&cache->dirs);
 }
 
 /** Remove a bftw_file from the LRU list. */
@@ -136,6 +139,7 @@ static void bftw_file_close(struct bftw_cache *cache, struct bftw_file *file) {
 	if (file->dir) {
 		bfs_assert(file->fd == bfs_dirfd(file->dir));
 		bfs_closedir(file->dir);
+		arena_free(&cache->dirs, file->dir);
 		file->dir = NULL;
 	} else {
 		xclose(file->fd);
@@ -157,9 +161,10 @@ static void bftw_file_freedir(struct bftw_cache *cache, struct bftw_file *file)
 	bool pinned = file->pincount > 0;
 
 	if (reffed || pinned) {
-		int fd = bfs_freedir(file->dir, pinned);
+		int fd = bfs_fdclosedir(file->dir, pinned);
 		if (fd >= 0) {
 			file->fd = fd;
+			arena_free(&cache->dirs, file->dir);
 			file->dir = NULL;
 		}
 	} else {
@@ -243,6 +248,7 @@ static void bftw_cache_destroy(struct bftw_cache *cache) {
 	bfs_assert(!cache->target);
 
 	varena_destroy(&cache->files);
+	arena_destroy(&cache->dirs);
 }
 
 /** Create a new bftw_file. */
@@ -410,10 +416,17 @@ static struct bfs_dir *bftw_file_opendir(struct bftw_cache *cache, struct bftw_f
 		return NULL;
 	}
 
-	struct bfs_dir *dir = bfs_opendir(fd, NULL);
-	if (dir) {
-		bftw_file_set_dir(cache, file, dir);
+	struct bfs_dir *dir = arena_alloc(&cache->dirs);
+	if (!dir) {
+		return NULL;
+	}
+
+	if (bfs_opendir(dir, fd, NULL) != 0) {
+		arena_free(&cache->dirs, dir);
+		return NULL;
 	}
+
+	bftw_file_set_dir(cache, file, dir);
 	return dir;
 }
 
@@ -900,14 +913,18 @@ static void bftw_push_dir(struct bftw_state *state, struct bftw_file *file) {
 			goto unpin;
 		}
 	}
-	--cache->capacity;
 
-	if (ioq_opendir(state->ioq, dfd, file->name, file) != 0) {
-		++cache->capacity;
+	struct bfs_dir *dir = arena_alloc(&state->cache.dirs);
+	if (!dir) {
 		goto unpin;
 	}
 
+	if (ioq_opendir(state->ioq, dir, dfd, file->name, file) != 0) {
+		goto free;
+	}
+
 	file->ioqueued = true;
+	--cache->capacity;
 
 	if (state->flags & BFTW_SORT) {
 		goto append;
@@ -915,6 +932,8 @@ static void bftw_push_dir(struct bftw_state *state, struct bftw_file *file) {
 		return;
 	}
 
+free:
+	arena_free(&state->cache.dirs, dir);
 unpin:
 	if (file->parent) {
 		bftw_cache_unpin(cache, file->parent);
@@ -950,7 +969,9 @@ static int bftw_ioq_pop(struct bftw_state *state, bool block) {
 		bftw_cache_unpin(cache, file->parent);
 	}
 
-	if (res->dir) {
+	if (res->error) {
+		arena_free(&state->cache.dirs, res->dir);
+	} else {
 		bftw_file_set_dir(cache, file, res->dir);
 	}
 
diff --git a/src/dir.c b/src/dir.c
index b9fd74d..a24b572 100644
--- a/src/dir.c
+++ b/src/dir.c
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: 0BSD
 
 #include "dir.h"
+#include "alloc.h"
 #include "bfstd.h"
 #include "config.h"
 #include "diag.h"
@@ -120,26 +121,26 @@ struct bfs_dir {
 #  define DIR_SIZE sizeof(struct bfs_dir)
 #endif
 
-struct bfs_dir *bfs_opendir(int at_fd, const char *at_path) {
-	struct bfs_dir *dir = malloc(DIR_SIZE);
-	if (!dir) {
-		return NULL;
-	}
+struct bfs_dir *bfs_allocdir(void) {
+	return malloc(DIR_SIZE);
+}
+
+void bfs_dir_arena(struct arena *arena) {
+	arena_init(arena, alignof(struct bfs_dir), DIR_SIZE);
+}
 
+int bfs_opendir(struct bfs_dir *dir, int at_fd, const char *at_path) {
 	int fd;
 	if (at_path) {
 		fd = openat(at_fd, at_path, O_RDONLY | O_CLOEXEC | O_DIRECTORY);
+		if (fd < 0) {
+			return -1;
+		}
 	} else if (at_fd >= 0) {
 		fd = at_fd;
 	} else {
-		free(dir);
 		errno = EBADF;
-		return NULL;
-	}
-
-	if (fd < 0) {
-		free(dir);
-		return NULL;
+		return -1;
 	}
 
 #if BFS_GETDENTS
@@ -152,14 +153,13 @@ struct bfs_dir *bfs_opendir(int at_fd, const char *at_path) {
 		if (at_path) {
 			close_quietly(fd);
 		}
-		free(dir);
-		return NULL;
+		return -1;
 	}
 	dir->de = NULL;
 #endif
 
 	dir->eof = false;
-	return dir;
+	return 0;
 }
 
 int bfs_dirfd(const struct bfs_dir *dir) {
@@ -291,17 +291,16 @@ int bfs_closedir(struct bfs_dir *dir) {
 		bfs_verify(errno != EBADF);
 	}
 #endif
-	free(dir);
+
+	sanitize_uninit(dir, DIR_SIZE);
 	return ret;
 }
 
-int bfs_freedir(struct bfs_dir *dir, bool same_fd) {
+int bfs_fdclosedir(struct bfs_dir *dir, bool same_fd) {
 #if BFS_GETDENTS
 	int ret = dir->fd;
-	free(dir);
 #elif __FreeBSD__
 	int ret = fdclosedir(dir->dir);
-	free(dir);
 #else
 	if (same_fd) {
 		errno = ENOTSUP;
@@ -309,10 +308,13 @@ int bfs_freedir(struct bfs_dir *dir, bool same_fd) {
 	}
 
 	int ret = dup_cloexec(dirfd(dir->dir));
-	if (ret >= 0) {
-		bfs_closedir(dir);
+	if (ret < 0) {
+		return -1;
 	}
+
+	bfs_closedir(dir);
 #endif
 
+	sanitize_uninit(dir, DIR_SIZE);
 	return ret;
 }
diff --git a/src/dir.h b/src/dir.h
index 6fe7ae2..16f592e 100644
--- a/src/dir.h
+++ b/src/dir.h
@@ -8,6 +8,7 @@
 #ifndef BFS_DIR_H
 #define BFS_DIR_H
 
+#include "alloc.h"
 #include "config.h"
 #include <sys/types.h>
 
@@ -62,17 +63,35 @@ struct bfs_dirent {
 };
 
 /**
+ * Allocate space for a directory.
+ *
+ * @return
+ *         An allocated, unopen directory, or NULL on failure.
+ */
+struct bfs_dir *bfs_allocdir(void);
+
+/**
+ * Initialize an arena for directories.
+ *
+ * @param arena
+ *         The arena to initialize.
+ */
+void bfs_dir_arena(struct arena *arena);
+
+/**
  * Open a directory.
  *
+ * @param dir
+ *         The allocated directory.
  * @param at_fd
  *         The base directory for path resolution.
  * @param at_path
  *         The path of the directory to open, relative to at_fd.  Pass NULL to
  *         open at_fd itself.
  * @return
- *         The opened directory, or NULL on failure.
+ *         0 on success, or -1 on failure.
  */
-struct bfs_dir *bfs_opendir(int at_fd, const char *at_path);
+int bfs_opendir(struct bfs_dir *dir, int at_fd, const char *at_path);
 
 /**
  * Get the file descriptor for a directory.
@@ -110,7 +129,7 @@ int bfs_readdir(struct bfs_dir *dir, struct bfs_dirent *de);
 int bfs_closedir(struct bfs_dir *dir);
 
 /**
- * Free a directory, keeping an open file descriptor to it.
+ * Extract the file descriptor from an open directory.
  *
  * @param dir
  *         The directory to free.
@@ -122,6 +141,6 @@ int bfs_closedir(struct bfs_dir *dir);
  *         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, bool same_fd);
+int bfs_fdclosedir(struct bfs_dir *dir, bool same_fd);
 
 #endif // BFS_DIR_H
diff --git a/src/eval.c b/src/eval.c
index f16821e..5f27681 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -421,10 +421,15 @@ bool eval_empty(const struct bfs_expr *expr, struct bfs_eval *state) {
 	const struct BFTW *ftwbuf = state->ftwbuf;
 
 	if (ftwbuf->type == BFS_DIR) {
-		struct bfs_dir *dir = bfs_opendir(ftwbuf->at_fd, ftwbuf->at_path);
+		struct bfs_dir *dir = bfs_allocdir();
 		if (!dir) {
 			eval_report_error(state);
-			goto done;
+			return ret;
+		}
+
+		if (bfs_opendir(dir, ftwbuf->at_fd, ftwbuf->at_path) != 0) {
+			eval_report_error(state);
+			return ret;
 		}
 
 		int did_read = bfs_readdir(dir, NULL);
@@ -435,6 +440,7 @@ bool eval_empty(const struct bfs_expr *expr, struct bfs_eval *state) {
 		}
 
 		bfs_closedir(dir);
+		free(dir);
 	} else if (ftwbuf->type == BFS_REG) {
 		const struct bfs_stat *statbuf = eval_stat(state);
 		if (statbuf) {
@@ -442,7 +448,6 @@ bool eval_empty(const struct bfs_expr *expr, struct bfs_eval *state) {
 		}
 	}
 
-done:
 	return ret;
 }
 
@@ -1495,20 +1500,25 @@ static int infer_fdlimit(const struct bfs_ctx *ctx, int limit) {
 
 	// Check /proc/self/fd for the current number of open fds, if possible
 	// (we may have inherited more than just the standard ones)
-	struct bfs_dir *dir = bfs_opendir(AT_FDCWD, "/proc/self/fd");
+	struct bfs_dir *dir = bfs_allocdir();
 	if (!dir) {
-		dir = bfs_opendir(AT_FDCWD, "/dev/fd");
+		goto done;
 	}
-	if (dir) {
-		// Account for 'dir' itself
-		nopen = -1;
 
-		while (bfs_readdir(dir, NULL) > 0) {
-			++nopen;
-		}
+	if (bfs_opendir(dir, AT_FDCWD, "/proc/self/fd") != 0
+	    && bfs_opendir(dir, AT_FDCWD, "/dev/fd") != 0) {
+		goto done;
+	}
 
-		bfs_closedir(dir);
+	// Account for 'dir' itself
+	nopen = -1;
+
+	while (bfs_readdir(dir, NULL) > 0) {
+		++nopen;
 	}
+	bfs_closedir(dir);
+done:
+	free(dir);
 
 	int ret = limit - nopen;
 	ret -= ctx->expr->persistent_fds;
diff --git a/src/ioq.c b/src/ioq.c
index 33316fa..47b082a 100644
--- a/src/ioq.c
+++ b/src/ioq.c
@@ -20,9 +20,11 @@
  * An I/O queue request.
  */
 struct ioq_req {
+	/** Directory allocation. */
+	struct bfs_dir *dir;
 	/** Base file descriptor for openat(). */
 	int dfd;
-	/** Relative path to dfd. */
+	/** Path to open, relative to dfd. */
 	const char *path;
 
 	/** Arbitrary user data. */
@@ -295,10 +297,12 @@ static void *ioq_work(void *ptr) {
 
 		struct ioq_res *res = &cmd->res;
 		res->ptr = req.ptr;
-		res->dir = bfs_opendir(req.dfd, req.path);
-		res->error = errno;
-		if (res->dir) {
+		res->dir = req.dir;
+		res->error = 0;
+		if (bfs_opendir(req.dir, req.dfd, req.path) == 0) {
 			bfs_polldir(res->dir);
+		} else {
+			res->error = errno;
 		}
 
 		ioqq_push(ioq->ready, cmd);
@@ -344,7 +348,7 @@ fail:
 	return NULL;
 }
 
-int ioq_opendir(struct ioq *ioq, int dfd, const char *path, void *ptr) {
+int ioq_opendir(struct ioq *ioq, struct bfs_dir *dir, int dfd, const char *path, void *ptr) {
 	if (ioq->size >= ioq->depth) {
 		return -1;
 	}
@@ -355,6 +359,7 @@ int ioq_opendir(struct ioq *ioq, int dfd, const char *path, void *ptr) {
 	}
 
 	struct ioq_req *req = &cmd->req;
+	req->dir = dir;
 	req->dfd = dfd;
 	req->path = path;
 	req->ptr = ptr;
diff --git a/src/ioq.h b/src/ioq.h
index 0af5779..50e02b1 100644
--- a/src/ioq.h
+++ b/src/ioq.h
@@ -45,6 +45,8 @@ struct ioq *ioq_create(size_t depth, size_t nthreads);
  *
  * @param ioq
  *         The I/O queue.
+ * @param dir
+ *         The allocated directory.
  * @param dfd
  *         The base file descriptor.
  * @param path
@@ -54,7 +56,7 @@ struct ioq *ioq_create(size_t depth, size_t nthreads);
  * @return
  *         0 on success, or -1 on failure.
  */
-int ioq_opendir(struct ioq *ioq, int dfd, const char *path, void *ptr);
+int ioq_opendir(struct ioq *ioq, struct bfs_dir *dir, int dfd, const char *path, void *ptr);
 
 /**
  * Pop a response from the queue.