The verify_only option performs only verification (reads performed
in do_verify()) and no read or write workload. The goal is to verify
previously written meta data quickly and be able to detect stale data.
Without this option, fio does not detect stale data from previous
fio runs---only data corruption of "misplaced" data.
This option replays the specified write workload sequence in order to
compute the "generation number" (using numberio field) for each block
header that was written in a previous fio run. The numberio field is
used to detect stale data. do_verify() checks numberio only in the
last iteration, after the correct numberio for each block has been
computed.
---
HOWTO | 8 ++++++-
README | 2 ++
backend.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
init.c | 17 +++++++++++++++
options.c | 9 ++++++++
thread_options.h | 2 ++
verify.c | 8 +++++--
7 files changed, 106 insertions(+), 4 deletions(-)
diff --git a/HOWTO b/HOWTO
index 005dac2..ac35342 100644
--- a/HOWTO
+++ b/HOWTO
@@ -1039,6 +1039,10 @@ loops=int Run the specified number of iterations of this job. Used
to repeat the same workload a given number of times. Defaults
to 1.
+verify_only Check for stale data written to storage in a previous fio run.
+ The workload used must match the one used in the previous run.
+ This works for workloads that write data.
+
do_verify=bool Run the verify phase after a write phase. Only makes sense if
verify is set. Defaults to 1.
@@ -1077,7 +1081,9 @@ verify=str If writing to a file, fio can verify the file contents
meta Write extra information about each io
(timestamp, block number etc.). The block
- number is verified. See also verify_pattern.
+ number is verified. The io sequence number is
+ verified for workloads that write data.
+ See also verify_pattern.
null Only pretend to verify. Useful for testing
internals with ioengine=null, not for much
diff --git a/README b/README
index 15a0731..7942069 100644
--- a/README
+++ b/README
@@ -141,6 +141,8 @@ $ fio
--latency-log Generate per-job latency logs
--bandwidth-log Generate per-job bandwidth logs
--minimal Minimal (terse) output
+ --verifyonly Skip workload io and only verify data
+ (includes stale data check)
--output-format=type Output format (terse,json,normal)
--terse-version=type Terse version output format (default 3, or 2 or 4).
--version Print version info and exit
diff --git a/backend.c b/backend.c
index b9c1c12..39c2ba7 100644
--- a/backend.c
+++ b/backend.c
@@ -1104,6 +1104,65 @@ static int exec_string(struct thread_options *o, const char *string, const char
}
/*
+ * Dry run to compute correct state of numberio for verification.
+ */
+static uint64_t do_dry_run(struct thread_data *td)
+{
+ uint64_t bytes_done[DDIR_RWDIR_CNT] = { 0, 0, 0 };
+ unsigned int i;
+ int ret = 0;
+
+ if (in_ramp_time(td))
+ td_set_runstate(td, TD_RAMP);
+ else
+ td_set_runstate(td, TD_RUNNING);
+
+ while ((td->o.read_iolog_file && !flist_empty(&td->io_log_list)) ||
+ (!flist_empty(&td->trim_list)) || !io_bytes_exceeded(td) ||
+ td->o.time_based) {
+ struct io_u *io_u;
+ enum fio_ddir ddir;
+
+ if (td->terminate || td->done)
+ break;
+
+ if (flow_threshold_exceeded(td))
+ continue;
+
+ io_u = get_io_u(td);
+ if (!io_u)
+ break;
+
+ ddir = io_u->ddir;
+
+ /*
+ * Substitute for td_io_queue(); avoids any io
+ */
+ io_u->flags |= IO_U_F_FLIGHT;
+ io_u->error = 0;
+ io_u->resid = 0;
+ if (ddir_rw(acct_ddir(io_u)))
+ td->io_issues[acct_ddir(io_u)]++;
+ if (ddir_rw(io_u->ddir)) {
+ io_u_mark_depth(td, 1);
+ td->ts.total_io_u[io_u->ddir]++;
+ }
+
+ ret = io_u_sync_complete(td, io_u, bytes_done);
+
+ if (!ddir_rw_sum(bytes_done) && !(td->io_ops->flags & FIO_NOIO))
+ continue;
+ }
+
+ if (td->o.fill_device && td->error == ENOSPC) {
+ td->error = 0;
+ td->terminate = 1;
+ }
+
+ return bytes_done[DDIR_WRITE] + bytes_done[DDIR_TRIM];
+}
+
+/*
* Entry point for the thread based jobs. The process based jobs end up
* here as well, after a little setup.
*/
@@ -1311,7 +1370,10 @@ static void *thread_main(void *data)
prune_io_piece_log(td);
- verify_bytes = do_io(td);
+ if (td->o.verify_only && (td_write(td) || td_rw(td)))
+ verify_bytes = do_dry_run(td);
+ else
+ verify_bytes = do_io(td);
clear_state = 1;
diff --git a/init.c b/init.c
index 1afc341..34d1f14 100644
--- a/init.c
+++ b/init.c
@@ -60,6 +60,8 @@ int write_bw_log = 0;
int read_only = 0;
int status_interval = 0;
+int verify_only = 0;
+
static int write_lat_log;
static int prev_group_jobs;
@@ -139,6 +141,11 @@ static struct option l_opts[FIO_NR_OPTIONS] = {
.val = 'r' | FIO_CLIENT_FLAG,
},
{
+ .name = (char *) "verifyonly",
+ .has_arg = no_argument,
+ .val = 'y' | FIO_CLIENT_FLAG,
+ },
+ {
.name = (char *) "eta",
.has_arg = required_argument,
.val = 'e' | FIO_CLIENT_FLAG,
@@ -928,6 +935,13 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num,
int numjobs, file_alloced;
struct thread_options *o = &td->o;
+ /*
+ * Ensure job option verify_only is set when provided as a
+ * command-line argument.
+ */
+ if (verify_only)
+ o->verify_only = 1;
+
/*
* the def_thread is just for options, it's not a real job
*/
@@ -1661,6 +1675,9 @@ int parse_cmd_line(int argc, char *argv[], int client_type)
case 'r':
read_only = 1;
break;
+ case 'y':
+ verify_only = 1;
+ break;
case 'v':
if (!cur_client) {
log_info("%s\n", fio_version_string);
diff --git a/options.c b/options.c
index caf89d3..e6b9ec9 100644
--- a/options.c
+++ b/options.c
@@ -1935,6 +1935,15 @@ struct fio_option fio_options[FIO_MAX_OPTS] = {
.group = FIO_OPT_G_RUNTIME,
},
{
+ .name = "verify_only",
+ .lname = "Verify only",
+ .type = FIO_OPT_STR_SET,
+ .off1 = td_var_offset(verify_only),
+ .help = "Verifies previously written data is still valid",
+ .category = FIO_OPT_C_GENERAL,
+ .group = FIO_OPT_G_RUNTIME,
+ },
+ {
.name = "ramp_time",
.lname = "Ramp time",
.type = FIO_OPT_STR_VAL_TIME,
diff --git a/thread_options.h b/thread_options.h
index 3f345c5..c9660b4 100644
--- a/thread_options.h
+++ b/thread_options.h
@@ -107,6 +107,8 @@ struct thread_options {
unsigned int fsync_on_close;
unsigned int bs_is_seq_rand;
+ unsigned int verify_only;
+
unsigned int random_distribution;
fio_fp64_t zipf_theta;
diff --git a/verify.c b/verify.c
index 63def12..9343ab9 100644
--- a/verify.c
+++ b/verify.c
@@ -373,10 +373,14 @@ static int verify_io_u_meta(struct verify_header *hdr, struct vcont *vc)
* For read-only workloads, the program cannot be certain of the
* last numberio written to a block. Checking of numberio will be done
* only for workloads that write data.
+ * For verify_only, numberio will be checked in the last iteration when
+ * the correct state of numberio, that would have been written to each
+ * block in a previous run of fio, has been reached.
*/
if (td_write(td) || td_rw(td))
- if (vh->numberio != io_u->numberio)
- ret = EILSEQ;
+ if (!td->o.verify_only || td->o.loops == 0)
+ if (vh->numberio != io_u->numberio)
+ ret = EILSEQ;
if (!ret)
return 0;
--
1.7.12.4
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