On Sat, Feb 15, 2025 at 4:14 PM Cedric Blancher via Cygwin
<[email protected]> wrote:
> Could Cygwin 3.6 please support fcntl(...,F_FREESP,...) and
> cntl(...,F_FREESP64,...), as specified in
> https://docs.oracle.com/cd/E19253-01/816-5167/fcntl-2/index.html
>
> Lots of older software from Solaris, SUPER/UX, CrayOS use F_FREESP for
> punching a hole into a file, and IMO it'll be nice if this works for
> Cygwin out of the box.
1. Ced: Could you please check whether the prototype code works for
you ? If "yes" then I'll make a patch for cygwin.dll based on this...
2. Takashi: What do you think ? The API comes from Solaris, and is
implememted by at least FreeBSD, Unicos, SUPER/UX, etc. and is usually
used by database and HPC software.
Prototype patch:
---- snip ----
#ifndef F_FREESP
#define F_FREESP 15
#endif
#ifndef F_ALLOCSP
#define F_ALLOCSP 16
#endif
/* FIXME: This should use a |struct flock| like Solaris/FreeBSD |fnctl()| */
int fcntl_sparse_space_management_emulate(int fd, int cmd, off_t
offset, off_t len)
{
off_t file_size;
off_t end;
file_size = lseek(fd, 0, SEEK_END);
if (file_size == (off_t)-1)
return -1;
if (len == 0)
end = file_size;
else
end = offset + len;
switch (cmd) {
case F_FREESP:
if (offset >= file_size)
return 0;
if (end >= file_size) {
return ftruncate(fd, offset);
} else {
if (fallocate(fd,
FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
offset,
end - offset) == -1) {
return -1;
}
}
return 0;
case F_ALLOCSP:
if (len == 0) {
return 0;
}
if (fallocate(fd, 0, offset, len) == -1) {
return -1;
}
return 0;
default:
errno = EINVAL;
return -1;
}
}
---- snip ----
----
Bye,
Roland
--
__ . . __
(o.\ \/ /.o) [email protected]
\__\/\/__/ MPEG specialist, C&&JAVA&&Sun&&Unix programmer
/O /==\ O\ TEL +49 641 3992797
(;O/ \/ \O;)
--
Problem reports: https://cygwin.com/problems.html
FAQ: https://cygwin.com/faq/
Documentation: https://cygwin.com/docs.html
Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
