| /* |
| * blktrace support code for fio |
| */ |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/stat.h> |
| #include <dirent.h> |
| |
| #include "list.h" |
| #include "fio.h" |
| #include "blktrace_api.h" |
| |
| #define TRACE_FIFO_SIZE 65536 |
| |
| /* |
| * fifo refill frontend, to avoid reading data in trace sized bites |
| */ |
| static int refill_fifo(struct thread_data *td, struct fifo *fifo, int fd) |
| { |
| char buf[TRACE_FIFO_SIZE]; |
| unsigned int total; |
| int ret; |
| |
| total = sizeof(buf); |
| if (total > fifo_room(fifo)) |
| total = fifo_room(fifo); |
| |
| ret = read(fd, buf, total); |
| if (ret < 0) { |
| td_verror(td, errno, "read blktrace file"); |
| return -1; |
| } |
| |
| if (ret > 0) |
| ret = fifo_put(fifo, buf, ret); |
| |
| return ret; |
| } |
| |
| /* |
| * Retrieve 'len' bytes from the fifo, refilling if necessary. |
| */ |
| static int trace_fifo_get(struct thread_data *td, struct fifo *fifo, int fd, |
| void *buf, unsigned int len) |
| { |
| if (fifo_len(fifo) < len) { |
| int ret = refill_fifo(td, fifo, fd); |
| |
| if (ret < 0) |
| return ret; |
| } |
| |
| return fifo_get(fifo, buf, len); |
| } |
| |
| /* |
| * Just discard the pdu by seeking past it. |
| */ |
| static int discard_pdu(struct thread_data *td, struct fifo *fifo, int fd, |
| struct blk_io_trace *t) |
| { |
| if (t->pdu_len == 0) |
| return 0; |
| |
| return trace_fifo_get(td, fifo, fd, NULL, t->pdu_len); |
| } |
| |
| /* |
| * 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) |
| 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; |
| } |
| |
| static int lookup_device(char *path, unsigned int maj, unsigned int min) |
| { |
| struct dirent *dir; |
| struct stat st; |
| int found = 0; |
| DIR *D; |
| |
| D = opendir(path); |
| if (!D) |
| return 0; |
| |
| while ((dir = readdir(D)) != NULL) { |
| char full_path[256]; |
| |
| if (!strcmp(dir->d_name, ".") || !strcmp(dir->d_name, "..")) |
| continue; |
| |
| sprintf(full_path, "%s/%s", path, dir->d_name); |
| if (lstat(full_path, &st) == -1) { |
| perror("lstat"); |
| break; |
| } |
| |
| if (S_ISDIR(st.st_mode)) { |
| found = lookup_device(full_path, maj, min); |
| if (found) { |
| strcpy(path, full_path); |
| break; |
| } |
| } |
| |
| if (!S_ISBLK(st.st_mode)) |
| continue; |
| |
| if (maj == major(st.st_rdev) && min == minor(st.st_rdev)) { |
| strcpy(path, full_path); |
| found = 1; |
| break; |
| } |
| } |
| |
| closedir(D); |
| return found; |
| } |
| |
| #define FMINORBITS 20 |
| #define FMINORMASK ((1U << FMINORBITS) - 1) |
| #define FMAJOR(dev) ((unsigned int) ((dev) >> FMINORBITS)) |
| #define FMINOR(dev) ((unsigned int) ((dev) & FMINORMASK)) |
| |
| static void trace_add_file(struct thread_data *td, __u32 device) |
| { |
| static unsigned int last_maj, last_min; |
| unsigned int maj = FMAJOR(device); |
| unsigned int min = FMINOR(device); |
| struct fio_file *f; |
| char dev[256]; |
| unsigned int i; |
| |
| if (last_maj == maj && last_min == min) |
| return; |
| |
| last_maj = maj; |
| last_min = min; |
| |
| /* |
| * check for this file in our list |
| */ |
| for_each_file(td, f, i) |
| if (f->major == maj && f->minor == min) |
| return; |
| |
| strcpy(dev, "/dev"); |
| if (lookup_device(dev, maj, min)) |
| add_file(td, dev); |
| } |
| |
| /* |
| * 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, |
| unsigned int *bs) |
| { |
| int rw; |
| |
| if ((t->action & 0xffff) != __BLK_TA_QUEUE) |
| return; |
| if (t->action & BLK_TC_ACT(BLK_TC_PC)) |
| return; |
| if (t->action & BLK_TC_ACT(BLK_TC_NOTIFY)) |
| return; |
| |
| trace_add_file(td, t->device); |
| |
| rw = (t->action & BLK_TC_ACT(BLK_TC_WRITE)) != 0; |
| |
| if (t->bytes > bs[rw]) |
| bs[rw] = t->bytes; |
| |
| ios[rw]++; |
| td->o.size += t->bytes; |
| 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, delay; |
| struct blk_io_trace t; |
| unsigned long ios[2]; |
| unsigned int cpu; |
| unsigned int rw_bs[2]; |
| struct fifo *fifo; |
| int fd; |
| |
| fd = open(filename, O_RDONLY); |
| if (fd < 0) { |
| td_verror(td, errno, "open blktrace file"); |
| return 1; |
| } |
| |
| fifo = fifo_alloc(TRACE_FIFO_SIZE); |
| |
| td->o.size = 0; |
| |
| cpu = 0; |
| ttime = 0; |
| ios[0] = ios[1] = 0; |
| rw_bs[0] = rw_bs[1] = 0; |
| do { |
| int ret = trace_fifo_get(td, fifo, fd, &t, sizeof(t)); |
| |
| if (ret < 0) |
| goto err; |
| else if (!ret) |
| break; |
| else if (ret < (int) sizeof(t)) { |
| log_err("fio: short fifo get\n"); |
| break; |
| } |
| |
| if ((t.magic & 0xffffff00) != BLK_IO_TRACE_MAGIC) { |
| log_err("fio: bad magic in blktrace data: %x\n", t.magic); |
| 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(td, fifo, fd, &t); |
| if (ret < 0) { |
| td_verror(td, ret, "blktrace lseek"); |
| goto err; |
| } else if (t.pdu_len != ret) { |
| log_err("fio: discarded %d of %d\n", ret, t.pdu_len); |
| goto err; |
| } |
| if (!ttime) { |
| ttime = t.time; |
| cpu = t.cpu; |
| } |
| delay = 0; |
| if (cpu == t.cpu) |
| delay = t.time - ttime; |
| handle_trace(td, &t, delay, ios, rw_bs); |
| ttime = t.time; |
| cpu = t.cpu; |
| } while (1); |
| |
| fifo_free(fifo); |
| 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; |
| td->o.max_bs[DDIR_READ] = rw_bs[DDIR_READ]; |
| } else if (!ios[DDIR_READ] && ios[DDIR_WRITE]) { |
| td->o.td_ddir = TD_DDIR_WRITE; |
| td->o.max_bs[DDIR_WRITE] = rw_bs[DDIR_WRITE]; |
| } else { |
| td->o.td_ddir = TD_DDIR_RW; |
| td->o.max_bs[DDIR_READ] = rw_bs[DDIR_READ]; |
| td->o.max_bs[DDIR_WRITE] = rw_bs[DDIR_WRITE]; |
| } |
| |
| /* |
| * 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); |
| fifo_free(fifo); |
| return 1; |
| } |