Author: asomers
Date: Thu Sep 10 02:48:55 2020
New Revision: 365549
URL: https://svnweb.freebsd.org/changeset/base/365549
Log:
cp: use copy_file_range(2)
This has three advantages over write(2)/read(2):
* Fewer context switches and data copies
* Mostly preserves a file's sparseness
* On some file systems (currently NFS 4.2) the file system will perform the
copy in an especially efficient way.
Reviewed by: rmacklem
MFC after: 2 weeks
Sponsored by: Axcient
Differential Revision: https://reviews.freebsd.org/D26377
Modified:
head/bin/cp/utils.c
Modified: head/bin/cp/utils.c
==============================================================================
--- head/bin/cp/utils.c Thu Sep 10 01:49:53 2020 (r365548)
+++ head/bin/cp/utils.c Thu Sep 10 02:48:55 2020 (r365549)
@@ -212,27 +212,16 @@ copy_file(const FTSENT *entp, int dne)
err(1, "Not enough memory");
}
wtotal = 0;
- while ((rcount = read(from_fd, buf, bufsize)) > 0) {
- for (bufp = buf, wresid = rcount; ;
- bufp += wcount, wresid -= wcount) {
- wcount = write(to_fd, bufp, wresid);
- if (wcount <= 0)
- break;
- wtotal += wcount;
- if (info) {
- info = 0;
- (void)fprintf(stderr,
- "%s -> %s %3d%%\n",
- entp->fts_path, to.p_path,
- cp_pct(wtotal,
fs->st_size));
- }
- if (wcount >= (ssize_t)wresid)
- break;
- }
- if (wcount != (ssize_t)wresid) {
- warn("%s", to.p_path);
- rval = 1;
- break;
+ while ((rcount = copy_file_range(from_fd, NULL,
+ to_fd, NULL, bufsize, 0)) > 0)
+ {
+ wtotal += rcount;
+ if (info) {
+ info = 0;
+ (void)fprintf(stderr,
+ "%s -> %s %3d%%\n",
+ entp->fts_path, to.p_path,
+ cp_pct(wtotal, fs->st_size));
}
}
if (rcount < 0) {
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