| /* |
| * blktrace support code for fio |
| */ |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #include "list.h" |
| #include "fio.h" |
| #include "blktrace_api.h" |
| |
| /* |
| * Just discard the pdu by seeking past it. |
| */ |
| static int discard_pdu(int fd, struct blk_io_trace *t) |
| { |
| if (t->pdu_len == 0) |
| return 0; |
| |
| if (lseek(fd, t->pdu_len, SEEK_CUR) < 0) |
| return errno; |
| |
| return 0; |
| } |
| |
| /* |
| * Check if this is a blktrace binary data file. We read a single trace |
| * into memory and check for the magic signature. |
| */ |
| int is_blktrace(const char *filename) |
| { |
| struct blk_io_trace t; |
| int fd, ret; |
| |
| fd = open(filename, O_RDONLY); |
| if (fd < 0) { |
| perror("open blktrace"); |
| return 0; |
| } |
| |
| ret = read(fd, &t, sizeof(t)); |
| close(fd); |
| |
| if (ret < 0) { |
| perror("read blktrace"); |
| return 0; |
| } else if (ret != sizeof(t)) { |
| log_err("fio: short read on blktrace file\n"); |
| return 0; |
| } |
| |
| if ((t.magic & 0xffffff00) == BLK_IO_TRACE_MAGIC) |
| return 1; |
| |
| return 0; |
| } |
| |
| /* |
| * Store blk_io_trace data in an ipo for later retrieval. |
| */ |
| static void store_ipo(struct thread_data *td, unsigned long long offset, |
| unsigned int bytes, int rw, unsigned long long ttime) |
| { |
| struct io_piece *ipo = malloc(sizeof(*ipo)); |
| |
| memset(ipo, 0, sizeof(*ipo)); |
| INIT_LIST_HEAD(&ipo->list); |
| /* |
| * the 512 is wrong here, it should be the hardware sector size... |
| */ |
| ipo->offset = offset * 512; |
| ipo->len = bytes; |
| ipo->delay = ttime / 1000; |
| if (rw) |
| ipo->ddir = DDIR_WRITE; |
| else |
| ipo->ddir = DDIR_READ; |
| |
| list_add_tail(&ipo->list, &td->io_log_list); |
| } |
| |
| /* |
| * We only care for queue traces, most of the others are side effects |
| * due to internal workings of the block layer. |
| */ |
| static void handle_trace(struct thread_data *td, struct blk_io_trace *t, |
| unsigned long long ttime, unsigned long *ios) |
| { |
| int rw; |
| |
| if ((t->action & 0xffff) != __BLK_TA_QUEUE) |
| return; |
| if (t->action & BLK_TC_ACT(BLK_TC_PC)) |
| return; |
| |
| /* |
| * should not happen, need to look into that... |
| */ |
| if (!t->bytes) |
| return; |
| |
| rw = (t->action & BLK_TC_ACT(BLK_TC_WRITE)) != 0; |
| ios[rw]++; |
| store_ipo(td, t->sector, t->bytes, rw, ttime); |
| } |
| |
| /* |
| * Load a blktrace file by reading all the blk_io_trace entries, and storing |
| * them as io_pieces like the fio text version would do. |
| */ |
| int load_blktrace(struct thread_data *td, const char *filename) |
| { |
| unsigned long long ttime; |
| struct blk_io_trace t; |
| unsigned long ios[2]; |
| int fd; |
| |
| fd = open(filename, O_RDONLY); |
| if (fd < 0) { |
| td_verror(td, errno, "open blktrace file"); |
| return 1; |
| } |
| |
| ios[0] = ios[1] = 0; |
| ttime = 0; |
| do { |
| /* |
| * Once this is working fully, I'll add a layer between |
| * here and read to cache trace data. Then we can avoid |
| * doing itsy bitsy reads, but instead pull in a larger |
| * chunk of data at the time. |
| */ |
| int ret = read(fd, &t, sizeof(t)); |
| |
| if (ret < 0) { |
| td_verror(td, errno, "read blktrace file"); |
| goto err; |
| } else if (!ret) { |
| break; |
| } else if (ret != sizeof(t)) { |
| log_err("fio: short read on blktrace file\n"); |
| goto err; |
| } |
| |
| if ((t.magic & 0xffffff00) != BLK_IO_TRACE_MAGIC) { |
| log_err("fio: bad magic in blktrace data\n"); |
| goto err; |
| } |
| if ((t.magic & 0xff) != BLK_IO_TRACE_VERSION) { |
| log_err("fio: bad blktrace version %d\n", t.magic & 0xff); |
| goto err; |
| } |
| ret = discard_pdu(fd, &t); |
| if (ret) { |
| td_verror(td, ret, "blktrace lseek"); |
| goto err; |
| } |
| if (!ttime) |
| ttime = t.time; |
| handle_trace(td, &t, t.time - ttime, ios); |
| ttime = t.time; |
| } while (1); |
| |
| close(fd); |
| |
| if (!ios[DDIR_READ] && !ios[DDIR_WRITE]) { |
| log_err("fio: found no ios in blktrace data\n"); |
| return 1; |
| } else if (ios[DDIR_READ] && !ios[DDIR_READ]) |
| td->o.td_ddir = TD_DDIR_READ; |
| else if (!ios[DDIR_READ] && ios[DDIR_WRITE]) |
| td->o.td_ddir = TD_DDIR_WRITE; |
| else |
| td->o.td_ddir = TD_DDIR_RW; |
| |
| /* |
| * We need to do direct/raw ios to the device, to avoid getting |
| * read-ahead in our way. |
| */ |
| td->o.odirect = 1; |
| |
| return 0; |
| err: |
| close(fd); |
| return 1; |
| } |