1 /* 2 * libaio engine 3 * 4 * IO engine using the Linux native aio interface. 5 * 6 */ 7 #include <stdio.h> 8 #include <stdlib.h> 9 #include <unistd.h> 10 #include <errno.h> 11 #include <assert.h> 12 #include <libaio.h> 13 14 #include "../fio.h" 15 16 struct libaio_data { 17 io_context_t aio_ctx; 18 struct io_event *aio_events; 19 struct iocb **iocbs; 20 struct io_u **io_us; 21 int iocbs_nr; 22 }; 23 24 struct libaio_options { 25 struct thread_data *td; 26 unsigned int userspace_reap; 27 }; 28 29 static struct fio_option options[] = { 30 { 31 .name = "userspace_reap", 32 .lname = "Libaio userspace reaping", 33 .type = FIO_OPT_STR_SET, 34 .off1 = offsetof(struct libaio_options, userspace_reap), 35 .help = "Use alternative user-space reap implementation", 36 .category = FIO_OPT_C_ENGINE, 37 .group = FIO_OPT_G_LIBAIO, 38 }, 39 { 40 .name = NULL, 41 }, 42 }; 43 44 static int fio_libaio_prep(struct thread_data fio_unused *td, struct io_u *io_u) 45 { 46 struct fio_file *f = io_u->file; 47 48 if (io_u->ddir == DDIR_READ) 49 io_prep_pread(&io_u->iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset); 50 else if (io_u->ddir == DDIR_WRITE) 51 io_prep_pwrite(&io_u->iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset); 52 else if (ddir_sync(io_u->ddir)) 53 io_prep_fsync(&io_u->iocb, f->fd); 54 55 return 0; 56 } 57 58 static struct io_u *fio_libaio_event(struct thread_data *td, int event) 59 { 60 struct libaio_data *ld = td->io_ops->data; 61 struct io_event *ev; 62 struct io_u *io_u; 63 64 ev = ld->aio_events + event; 65 io_u = container_of(ev->obj, struct io_u, iocb); 66 67 if (ev->res != io_u->xfer_buflen) { 68 if (ev->res > io_u->xfer_buflen) 69 io_u->error = -ev->res; 70 else 71 io_u->resid = io_u->xfer_buflen - ev->res; 72 } else 73 io_u->error = 0; 74 75 return io_u; 76 } 77 78 struct aio_ring { 79 unsigned id; /** kernel internal index number */ 80 unsigned nr; /** number of io_events */ 81 unsigned head; 82 unsigned tail; 83 84 unsigned magic; 85 unsigned compat_features; 86 unsigned incompat_features; 87 unsigned header_length; /** size of aio_ring */ 88 89 struct io_event events[0]; 90 }; 91 92 #define AIO_RING_MAGIC 0xa10a10a1 93 94 static int user_io_getevents(io_context_t aio_ctx, unsigned int max, 95 struct io_event *events) 96 { 97 long i = 0; 98 unsigned head; 99 struct aio_ring *ring = (struct aio_ring*) aio_ctx; 100 101 while (i < max) { 102 head = ring->head; 103 104 if (head == ring->tail) { 105 /* There are no more completions */ 106 break; 107 } else { 108 /* There is another completion to reap */ 109 events[i] = ring->events[head]; 110 read_barrier(); 111 ring->head = (head + 1) % ring->nr; 112 i++; 113 } 114 } 115 116 return i; 117 } 118 119 static int fio_libaio_getevents(struct thread_data *td, unsigned int min, 120 unsigned int max, struct timespec *t) 121 { 122 struct libaio_data *ld = td->io_ops->data; 123 struct libaio_options *o = td->eo; 124 unsigned actual_min = td->o.iodepth_batch_complete == 0 ? 0 : min; 125 int r, events = 0; 126 127 do { 128 if (o->userspace_reap == 1 129 && actual_min == 0 130 && ((struct aio_ring *)(ld->aio_ctx))->magic 131 == AIO_RING_MAGIC) { 132 r = user_io_getevents(ld->aio_ctx, max, 133 ld->aio_events + events); 134 } else { 135 r = io_getevents(ld->aio_ctx, actual_min, 136 max, ld->aio_events + events, t); 137 } 138 if (r >= 0) 139 events += r; 140 else if (r == -EAGAIN) 141 usleep(100); 142 } while (events < min); 143 144 return r < 0 ? r : events; 145 } 146 147 static int fio_libaio_queue(struct thread_data *td, struct io_u *io_u) 148 { 149 struct libaio_data *ld = td->io_ops->data; 150 151 fio_ro_check(td, io_u); 152 153 if (ld->iocbs_nr == (int) td->o.iodepth) 154 return FIO_Q_BUSY; 155 156 /* 157 * fsync is tricky, since it can fail and we need to do it 158 * serialized with other io. the reason is that linux doesn't 159 * support aio fsync yet. So return busy for the case where we 160 * have pending io, to let fio complete those first. 161 */ 162 if (ddir_sync(io_u->ddir)) { 163 if (ld->iocbs_nr) 164 return FIO_Q_BUSY; 165 166 do_io_u_sync(td, io_u); 167 return FIO_Q_COMPLETED; 168 } 169 170 if (io_u->ddir == DDIR_TRIM) { 171 if (ld->iocbs_nr) 172 return FIO_Q_BUSY; 173 174 do_io_u_trim(td, io_u); 175 return FIO_Q_COMPLETED; 176 } 177 178 ld->iocbs[ld->iocbs_nr] = &io_u->iocb; 179 ld->io_us[ld->iocbs_nr] = io_u; 180 ld->iocbs_nr++; 181 return FIO_Q_QUEUED; 182 } 183 184 static void fio_libaio_queued(struct thread_data *td, struct io_u **io_us, 185 unsigned int nr) 186 { 187 struct timeval now; 188 unsigned int i; 189 190 if (!fio_fill_issue_time(td)) 191 return; 192 193 fio_gettime(&now, NULL); 194 195 for (i = 0; i < nr; i++) { 196 struct io_u *io_u = io_us[i]; 197 198 memcpy(&io_u->issue_time, &now, sizeof(now)); 199 io_u_queued(td, io_u); 200 } 201 } 202 203 static int fio_libaio_commit(struct thread_data *td) 204 { 205 struct libaio_data *ld = td->io_ops->data; 206 struct iocb **iocbs; 207 struct io_u **io_us; 208 int ret; 209 210 if (!ld->iocbs_nr) 211 return 0; 212 213 io_us = ld->io_us; 214 iocbs = ld->iocbs; 215 do { 216 ret = io_submit(ld->aio_ctx, ld->iocbs_nr, iocbs); 217 if (ret > 0) { 218 fio_libaio_queued(td, io_us, ret); 219 io_u_mark_submit(td, ret); 220 ld->iocbs_nr -= ret; 221 io_us += ret; 222 iocbs += ret; 223 ret = 0; 224 } else if (!ret || ret == -EAGAIN || ret == -EINTR) { 225 if (!ret) 226 io_u_mark_submit(td, ret); 227 continue; 228 } else 229 break; 230 } while (ld->iocbs_nr); 231 232 return ret; 233 } 234 235 static int fio_libaio_cancel(struct thread_data *td, struct io_u *io_u) 236 { 237 struct libaio_data *ld = td->io_ops->data; 238 239 return io_cancel(ld->aio_ctx, &io_u->iocb, ld->aio_events); 240 } 241 242 static void fio_libaio_cleanup(struct thread_data *td) 243 { 244 struct libaio_data *ld = td->io_ops->data; 245 246 if (ld) { 247 io_destroy(ld->aio_ctx); 248 free(ld->aio_events); 249 free(ld->iocbs); 250 free(ld->io_us); 251 free(ld); 252 } 253 } 254 255 static int fio_libaio_init(struct thread_data *td) 256 { 257 struct libaio_data *ld = malloc(sizeof(*ld)); 258 struct libaio_options *o = td->eo; 259 int err = 0; 260 261 memset(ld, 0, sizeof(*ld)); 262 263 /* 264 * First try passing in 0 for queue depth, since we don't 265 * care about the user ring. If that fails, the kernel is too old 266 * and we need the right depth. 267 */ 268 if (!o->userspace_reap) 269 err = io_queue_init(INT_MAX, &ld->aio_ctx); 270 if (o->userspace_reap || err == -EINVAL) 271 err = io_queue_init(td->o.iodepth, &ld->aio_ctx); 272 if (err) { 273 td_verror(td, -err, "io_queue_init"); 274 log_err("fio: check /proc/sys/fs/aio-max-nr\n"); 275 free(ld); 276 return 1; 277 } 278 279 ld->aio_events = malloc(td->o.iodepth * sizeof(struct io_event)); 280 memset(ld->aio_events, 0, td->o.iodepth * sizeof(struct io_event)); 281 ld->iocbs = malloc(td->o.iodepth * sizeof(struct iocb *)); 282 memset(ld->iocbs, 0, sizeof(struct iocb *)); 283 ld->io_us = malloc(td->o.iodepth * sizeof(struct io_u *)); 284 memset(ld->io_us, 0, td->o.iodepth * sizeof(struct io_u *)); 285 ld->iocbs_nr = 0; 286 287 td->io_ops->data = ld; 288 return 0; 289 } 290 291 static struct ioengine_ops ioengine = { 292 .name = "libaio", 293 .version = FIO_IOOPS_VERSION, 294 .init = fio_libaio_init, 295 .prep = fio_libaio_prep, 296 .queue = fio_libaio_queue, 297 .commit = fio_libaio_commit, 298 .cancel = fio_libaio_cancel, 299 .getevents = fio_libaio_getevents, 300 .event = fio_libaio_event, 301 .cleanup = fio_libaio_cleanup, 302 .open_file = generic_open_file, 303 .close_file = generic_close_file, 304 .get_file_size = generic_get_file_size, 305 .options = options, 306 .option_struct_size = sizeof(struct libaio_options), 307 }; 308 309 static void fio_init fio_libaio_register(void) 310 { 311 register_ioengine(&ioengine); 312 } 313 314 static void fio_exit fio_libaio_unregister(void) 315 { 316 unregister_ioengine(&ioengine); 317 } 318
