From 1f9f514e7c2ba41b0954d0141f99652f6a53a107 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Wed, 2 Aug 2017 01:53:46 -0700 Subject: When renaming a file, ask only if EEXIST or ENOSYS * src/fileio.c (Frename_file): Avoid calling Ffile_directory_p more than once on FILE. Use renameat_noreplace, so that we can ask the user (and unlink and retry) only if this fails with errno == EEXIST or ENOSYS. This avoids the need to ask the user for permission to do an operation that will fail anyway. Simplify computation of ok_if_already_exists for subsidiary functions. * src/filelock.c (rename_lock_file): Prefer renameat_noreplace if it works, as this avoids the need to link and unlink. * src/lisp.h (renameat_noreplace): New decl. * src/sysdep.c [HAVE_LINUX_FS_H]: Include linux/fs.h and sys/syscall.h. (renameat_noreplace): New function. --- src/filelock.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'src/filelock.c') diff --git a/src/filelock.c b/src/filelock.c index bfa1d63d833..dd8cb28c425 100644 --- a/src/filelock.c +++ b/src/filelock.c @@ -339,6 +339,9 @@ rename_lock_file (char const *old, char const *new, bool force) { struct stat st; + int r = renameat_noreplace (AT_FDCWD, old, AT_FDCWD, new); + if (! (r < 0 && errno == ENOSYS)) + return r; if (link (old, new) == 0) return unlink (old) == 0 || errno == ENOENT ? 0 : -1; if (errno != ENOSYS && errno != LINKS_MIGHT_NOT_WORK) -- cgit v1.2.3