1/*
2 * TRIM/DISCARD support
3 */
4#include <unistd.h>
5#include <fcntl.h>
6#include <string.h>
7#include <assert.h>
8#include <pthread.h>
9
10#include "fio.h"
11#include "trim.h"
12
13#ifdef FIO_HAVE_TRIM
14int get_next_trim(struct thread_data *td, struct io_u *io_u)
15{
16	struct io_piece *ipo;
17
18	/*
19	 * this io_u is from a requeue, we already filled the offsets
20	 */
21	if (io_u->file)
22		return 0;
23	if (flist_empty(&td->trim_list))
24		return 1;
25
26	assert(td->trim_entries);
27	ipo = flist_entry(td->trim_list.next, struct io_piece, trim_list);
28	remove_trim_entry(td, ipo);
29
30	io_u->offset = ipo->offset;
31	io_u->buflen = ipo->len;
32	io_u->file = ipo->file;
33
34	/*
35	 * If not verifying that trimmed ranges return zeroed data,
36	 * remove this from the to-read verify lists
37	 */
38	if (!td->o.trim_zero) {
39		if (ipo->flags & IP_F_ONLIST)
40			flist_del(&ipo->list);
41		else {
42			assert(ipo->flags & IP_F_ONRB);
43			rb_erase(&ipo->rb_node, &td->io_hist_tree);
44		}
45		td->io_hist_len--;
46		free(ipo);
47	} else
48		ipo->flags |= IP_F_TRIMMED;
49
50	if (!fio_file_open(io_u->file)) {
51		int r = td_io_open_file(td, io_u->file);
52
53		if (r) {
54			dprint(FD_VERIFY, "failed file %s open\n",
55					io_u->file->file_name);
56			return 1;
57		}
58	}
59
60	get_file(io_u->file);
61	assert(fio_file_open(io_u->file));
62	io_u->ddir = DDIR_TRIM;
63	io_u->xfer_buf = NULL;
64	io_u->xfer_buflen = io_u->buflen;
65
66	dprint(FD_VERIFY, "get_next_trim: ret io_u %p\n", io_u);
67	return 0;
68}
69
70int io_u_should_trim(struct thread_data *td, struct io_u *io_u)
71{
72	unsigned long long val;
73	unsigned long r;
74
75	if (!td->o.trim_percentage)
76		return 0;
77
78	if (td->o.use_os_rand) {
79		r = os_random_long(&td->trim_state);
80		val = (OS_RAND_MAX / 100ULL);
81	} else {
82		r = __rand(&td->__trim_state);
83		val = (FRAND_MAX / 100ULL);
84	}
85
86	val *= (unsigned long long) td->o.trim_percentage;
87	return r <= val;
88}
89#endif
90