[PATCH v2 8/9] fio: Support verify_write_sequence

[John Garry <john.g.garry@oracle.com>]

Add an option to disable verifying the write sequence number. By default,
it is enabled. However disable for verify_only mode.

Signed-off-by: John Garry <john.g.garry@oracle.com>
---
 HOWTO.rst        | 11 +++++++++++
 fio.1            |  8 ++++++++
 init.c           |  3 +++
 options.c        | 11 +++++++++++
 thread_options.h |  1 +
 verify.c         |  7 ++++---
 6 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/HOWTO.rst b/HOWTO.rst
index c6c9b306..4f071484 100644
--- a/HOWTO.rst
+++ b/HOWTO.rst
@@ -4002,6 +4002,17 @@ Verification
         instead resets the file after the write phase and then replays I/Os for
         the verification phase.
 
+.. option:: verify_write_sequence=bool
+
+        Verify the header write sequence number. In a scenario with multiple jobs,
+        verification of the write sequence number may fail. Disabling this option
+        will mean that write sequence number checking is skipped. Doing that can be
+        useful for testing atomic writes, as it means that checksum verification can
+        still be attempted. For when :option:`atomic` is enabled, checksum
+        verification is expected to succeed (while write sequence checking can still
+        fail).
+        Defaults to true.
+
 .. option:: trim_percentage=int
 
 	Number of verify blocks to discard/trim.
diff --git a/fio.1 b/fio.1
index 6e5bed9d..0fd0fb25 100644
--- a/fio.1
+++ b/fio.1
@@ -3726,6 +3726,14 @@ Enable experimental verification. Standard verify records I/O metadata for
 later use during the verification phase. Experimental verify instead resets the
 file after the write phase and then replays I/Os for the verification phase.
 .TP
+.BI verify_write_sequence \fR=\fPbool
+Verify the header write sequence number. In a scenario with multiple jobs,
+verification of the write sequence number may fail. Disabling this option
+will mean that write sequence number checking is skipped. Doing that can be
+useful for testing atomic writes, as it means that checksum verification can
+still be attempted. For when \fBatomic\fR is enabled, checksum verification
+is expected to succeed (while write sequence checking can still fail).
+.TP
 .BI trim_percentage \fR=\fPint
 Number of verify blocks to discard/trim.
 .TP
diff --git a/init.c b/init.c
index bad8b75b..96a03d98 100644
--- a/init.c
+++ b/init.c
@@ -853,6 +853,9 @@ static int fixup_options(struct thread_data *td)
 		    (o->max_bs[DDIR_WRITE] % o->verify_interval))
 			o->verify_interval = gcd(o->min_bs[DDIR_WRITE],
 							o->max_bs[DDIR_WRITE]);
+
+		if (td->o.verify_only)
+			o->verify_write_sequence = 0;
 	}
 
 	if (td->o.oatomic) {
diff --git a/options.c b/options.c
index 95567de6..c35878f7 100644
--- a/options.c
+++ b/options.c
@@ -3397,6 +3397,17 @@ struct fio_option fio_options[FIO_MAX_OPTS] = {
 		.category = FIO_OPT_C_IO,
 		.group	= FIO_OPT_G_VERIFY,
 	},
+	{
+		.name	= "verify_write_sequence",
+		.lname	= "Verify write sequence number",
+		.off1	= offsetof(struct thread_options, verify_write_sequence),
+		.type	= FIO_OPT_BOOL,
+		.def	= "1",
+		.help	= "Verify header write sequence number",
+		.parent	= "verify",
+		.category = FIO_OPT_C_IO,
+		.group	= FIO_OPT_G_VERIFY,
+	},
 #ifdef FIO_HAVE_TRIM
 	{
 		.name	= "trim_percentage",
diff --git a/thread_options.h b/thread_options.h
index ee1e5b31..d0e0a4ae 100644
--- a/thread_options.h
+++ b/thread_options.h
@@ -156,6 +156,7 @@ struct thread_options {
 	unsigned int experimental_verify;
 	unsigned int verify_state;
 	unsigned int verify_state_save;
+	unsigned int verify_write_sequence;
 	unsigned int use_thread;
 	unsigned int unlink;
 	unsigned int unlink_each_loop;
diff --git a/verify.c b/verify.c
index b2fede24..f3d228ba 100644
--- a/verify.c
+++ b/verify.c
@@ -848,12 +848,13 @@ static int verify_header(struct io_u *io_u, struct thread_data *td,
 	/*
 	 * 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 check is skipped.
+	 * done only for workloads that write data.  For verify_only or
+	 * any mode de-selecting verify_write_sequence, numberio check is
+	 * skipped.
 	 */
 	if (td_write(td) && (td_min_bs(td) == td_max_bs(td)) &&
 	    !td->o.time_based)
-		if (!td->o.verify_only)
+		if (td->o.verify_write_sequence)
 			if (hdr->numberio != io_u->numberio) {
 				log_err("verify: bad header numberio %"PRIu16
 					", wanted %"PRIu16,
-- 
2.31.1