From e400447222fb9db8d5b2b2e3de2892dbe22fa145 Mon Sep 17 00:00:00 2001 From: Michael Orlitzky Date: Thu, 1 Mar 2018 21:08:51 -0500 Subject: [PATCH] apply_default_acl_ex: avoid second call to safe_open() to speed things up. --- src/libadacl.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/src/libadacl.c b/src/libadacl.c index 36812e8..49628e7 100644 --- a/src/libadacl.c +++ b/src/libadacl.c @@ -672,14 +672,19 @@ int apply_default_acl_ex(const char* path, /* The file descriptor for the directory containing "path" */ int parent_fd = 0; + /* dirname() and basename() mangle their arguments, so we need + to make copies of "path" before using them. */ + char* dirname_path_copy = NULL; + char* basename_path_copy = NULL; + /* Get the parent directory of "path" with dirname(), which happens * to murder its argument and necessitates a path_copy. */ - char* path_copy = strdup(path); - if (path_copy == NULL) { + dirname_path_copy = strdup(path); + if (dirname_path_copy == NULL) { perror("apply_default_acl_ex (strdup)"); return ACL_ERROR; } - char* parent = dirname(path_copy); + char* parent = dirname(dirname_path_copy); parent_fd = safe_open(parent, O_DIRECTORY | O_NOFOLLOW); if (parent_fd == OPEN_ERROR) { if (errno == ELOOP || errno == ENOTDIR) { @@ -702,7 +707,16 @@ int apply_default_acl_ex(const char* path, goto cleanup; } - fd = safe_open(path, O_NOFOLLOW); + /* We already obtained the parent fd safely, so if we use the + basename of path here instead of the full thing, then we can get + away with using openat() and spare ourselves the slowness of + another safe_open(). */ + basename_path_copy = strdup(path); + if (basename_path_copy == NULL) { + perror("apply_default_acl_ex (strdup)"); + return ACL_ERROR; + } + fd = openat(parent_fd, basename(basename_path_copy), O_NOFOLLOW); if (fd == OPEN_ERROR) { if (errno == ELOOP || errno == ENOTDIR) { /* We hit a symlink, either in the last path component (ELOOP) @@ -890,7 +904,8 @@ int apply_default_acl_ex(const char* path, } cleanup: - free(path_copy); + free(dirname_path_copy); + free(basename_path_copy); if (new_acl != (acl_t)NULL) { acl_free(new_acl); } -- 2.43.2