On 2026-03-08 01:04, Collin Funk wrote:
The behavior you see is surprising to me.
Yes, I'm not understanding it either. Just to double check, he writes
that /tmp and /usr/bin are the same file system. In that case, 'cp -f
/usr/bin/nmap /tmp/nmap' should do something like this:
openat(AT_FDCWD, "/tmp/nmap", O_RDONLY|O_PATH|O_DIRECTORY) = -1
ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/bin/nmap", {st_mode=S_IFREG|0755,
st_size=138120, ...}, 0) = 0
openat(AT_FDCWD, "/usr/bin/nmap", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=138120, ...}) = 0
openat(AT_FDCWD, "/tmp/nmap", O_WRONLY|O_CREAT|O_EXCL, 0755) = 4
ioctl(4, BTRFS_IOC_CLONE or FICLONE, 3) = -1 EOPNOTSUPP (Operation
not supported)
fstat(4, {st_mode=S_IFREG|0755, st_size=0, ...}) = 0
lseek(3, 0, SEEK_DATA) = 0
lseek(3, 0, SEEK_HOLE) = 138120
lseek(3, 0, SEEK_SET) = 0
copy_file_range(3, NULL, 4, NULL, 2146435072, 0) = 138120
copy_file_range(3, NULL, 4, NULL, 2146435072, 0) = 0
close(4) = 0
close(3) = 0
and 'mv -f /tmp/nmap /usr/bin/nmap' should do something like this:
renameat2(AT_FDCWD, "/tmp/nmap", AT_FDCWD, "/usr/bin/nmap",
RENAME_NOREPLACE) = -1 EEXIST (File exists)
openat(AT_FDCWD, "/usr/bin/nmap", O_RDONLY|O_PATH|O_DIRECTORY) = -1
ENOTDIR (Not a directory)
newfstatat(AT_FDCWD, "/tmp/nmap", {st_mode=S_IFREG|0755,
st_size=138120, ...}, AT_SYMLINK_NOFOLLOW) = 0
newfstatat(AT_FDCWD, "/usr/bin/nmap", {st_mode=S_IFREG|0755,
st_size=138120, ...}, AT_SYMLINK_NOFOLLOW) = 0
renameat(AT_FDCWD, "/tmp/nmap", AT_FDCWD, "/usr/bin/nmap") = 0
He can use 'strace' to verify this, and if 'strace' reports anything
different we can take it from there.
I am assuming bleeding-edge coreutils; if he's using older coreutils
perhaps the older version has been fixed and he should upgrade.
