From 722287e443c93e04e724e2812857a395cfab0b60 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Thu, 3 Sep 2009 15:15:09 +0200 Subject: rm: improve efficiency of rm -r (without -f) from O(N^2) to O(N) where N is the depth of the deepest hierarchy rm is processing. * src/remove.c (write_protected_non_symlink): Use faccessat to avoid O(N)-per-entry cost of calling euidaccess. * m4/jm-macros.m4 (coreutils_MACROS): Check for faccessat. * NEWS (Improvements): Mention it. --- src/remove.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'src') diff --git a/src/remove.c b/src/remove.c index 32f67a181..2db385909 100644 --- a/src/remove.c +++ b/src/remove.c @@ -172,6 +172,13 @@ write_protected_non_symlink (int fd_cwd, mess up with long file names). */ { + /* Use faccessat if possible, so as to avoid the expense + of processing an N-component name. */ +#if HAVE_FACCESSAT && AT_EACCESS + if (faccessat (fd_cwd, file, W_OK, AT_EACCESS) == 0) + return 0; +#endif + /* This implements #5: */ size_t file_name_len = strlen (full_name); -- cgit v1.2.3-54-g00ecf