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cp: Remove fts sorting.

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In an attempt to improve performance, cp reordered directories first
(although the comment says directories last). This is not effective with new
UFS layout policies.

The sorting reorders multiple arguments passed to cp, which may be
undesirable.

Additionally, the comparison function does not induce a total order. Per
POSIX, this causes undefined behaviour in qsort().

NetBSD removed the sorting in 2009.

On filesystems that return directory entries in hash/btree order, sorting by
d_fileno before statting improves performance on large directories. However,
this can only be implemented in fts(3).

PR:		53475
Reviewed by:	bde (in 2004)
MFC after:	1 week
This commit is contained in:
Jilles Tjoelker 2015-05-05 13:23:03 +00:00
parent ba993026d4
commit c633f8dc04
1 changed files with 1 additions and 28 deletions
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29
bin/cp/cp.c
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@ -90,7 +90,6 @@ volatile sig_atomic_t info;
enum op { FILE_TO_FILE, FILE_TO_DIR, DIR_TO_DNE };
static int copy(char *[], enum op, int);
static int mastercmp(const FTSENT * const *, const FTSENT * const *);
static void siginfo(int __unused);
int
@ -274,7 +273,7 @@ copy(char *argv[], enum op type, int fts_options)
mask = ~umask(0777);
umask(~mask);
if ((ftsp = fts_open(argv, fts_options, mastercmp)) == NULL)
if ((ftsp = fts_open(argv, fts_options, NULL)) == NULL)
err(1, "fts_open");
for (badcp = rval = 0; (curr = fts_read(ftsp)) != NULL; badcp = 0) {
switch (curr->fts_info) {
@ -488,32 +487,6 @@ copy(char *argv[], enum op type, int fts_options)
return (rval);
}
/*
* mastercmp --
* The comparison function for the copy order. The order is to copy
* non-directory files before directory files. The reason for this
* is because files tend to be in the same cylinder group as their
* parent directory, whereas directories tend not to be. Copying the
* files first reduces seeking.
*/
static int
mastercmp(const FTSENT * const *a, const FTSENT * const *b)
{
int a_info, b_info;
a_info = (*a)->fts_info;
if (a_info == FTS_ERR || a_info == FTS_NS || a_info == FTS_DNR)
return (0);
b_info = (*b)->fts_info;
if (b_info == FTS_ERR || b_info == FTS_NS || b_info == FTS_DNR)
return (0);
if (a_info == FTS_D)
return (-1);
if (b_info == FTS_D)
return (1);
return (0);
}
static void
siginfo(int sig __unused)
{