From 5590ff0d5528b60153c0b4e7b771472b5a95e297 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Wed, 18 Jan 2006 17:43:53 -0800 Subject: [PATCH] vfs: *at functions: core Here is a series of patches which introduce in total 13 new system calls which take a file descriptor/filename pair instead of a single file name. These functions, openat etc, have been discussed on numerous occasions. They are needed to implement race-free filesystem traversal, they are necessary to implement a virtual per-thread current working directory (think multi-threaded backup software), etc. We have in glibc today implementations of the interfaces which use the /proc/self/fd magic. But this code is rather expensive. Here are some results (similar to what Jim Meyering posted before). The test creates a deep directory hierarchy on a tmpfs filesystem. Then rm -fr is used to remove all directories. Without syscall support I get this: real 0m31.921s user 0m0.688s sys 0m31.234s With syscall support the results are much better: real 0m20.699s user 0m0.536s sys 0m20.149s The interfaces are for obvious reasons currently not much used. But they'll be used. coreutils (and Jeff's posixutils) are already using them. Furthermore, code like ftw/fts in libc (maybe even glob) will also start using them. I expect a patch to make follow soon. Every program which is walking the filesystem tree will benefit. Signed-off-by: Ulrich Drepper Signed-off-by: Alexey Dobriyan Cc: Christoph Hellwig Cc: Al Viro Acked-by: Ingo Molnar Cc: Michael Kerrisk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/sparc64/kernel/sys_sparc32.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/sparc64') diff --git a/arch/sparc64/kernel/sys_sparc32.c b/arch/sparc64/kernel/sys_sparc32.c index d4b7a100cb8..9264ccbaaaf 100644 --- a/arch/sparc64/kernel/sys_sparc32.c +++ b/arch/sparc64/kernel/sys_sparc32.c @@ -821,7 +821,7 @@ asmlinkage long sys32_utimes(char __user *filename, return -EFAULT; } - return do_utimes(filename, (tvs ? &ktvs[0] : NULL)); + return do_utimes(AT_FDCWD, filename, (tvs ? &ktvs[0] : NULL)); } /* These are here just in case some old sparc32 binary calls it. */ @@ -1003,7 +1003,7 @@ asmlinkage long sys32_adjtimex(struct timex32 __user *utp) asmlinkage long sparc32_open(const char __user *filename, int flags, int mode) { - return do_sys_open(filename, flags, mode); + return do_sys_open(AT_FDCWD, filename, flags, mode); } extern unsigned long do_mremap(unsigned long addr, -- cgit