[PATCH 04/21] fio: add verify_header_seed option

[Ankit Kumar <ankit.kumar@samsung.com>]

Add a new option to disable the verify header seed check. The header
seed check is enabled by default.
There have been numerous issues observed with header seed mismatch. Hence
this allows end user to disable this check, and proceed with the checksum
verification. This is similar to option verify_write_sequence, which
allows the capability to disable write sequence number check.

Update the documentation accordingly.

Signed-off-by: Ankit Kumar <ankit.kumar@samsung.com>
---
 HOWTO.rst        | 14 ++++++++++++--
 cconv.c          |  2 ++
 fio.1            | 12 ++++++++++--
 options.c        | 11 +++++++++++
 server.h         |  2 +-
 thread_options.h |  3 ++-
 verify.c         |  2 +-
 7 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/HOWTO.rst b/HOWTO.rst
index c7c131e7..a221b9d8 100644
--- a/HOWTO.rst
+++ b/HOWTO.rst
@@ -3830,8 +3830,9 @@ Verification
 	of the job. Each verification method also implies verification of special
 	header, which is written to the beginning of each block. This header also
 	includes meta information, like offset of the block, block number, timestamp
-	when block was written, etc.  :option:`verify` can be combined with
-	:option:`verify_pattern` option.  The allowed values are:
+	when block was written, initial seed value used to generate the buffer
+	contents etc. :option:`verify` can be combined with :option:`verify_pattern`
+	option.  The allowed values are:
 
 		**md5**
 			Use an md5 sum of the data area and store it in the header of
@@ -4029,6 +4030,15 @@ Verification
         fail).
         Defaults to true.
 
+.. option:: verify_header_seed=bool
+
+	Verify the header seed value which was used to generate the buffer contents.
+	In certain scenarios with read / verify only workloads, when
+	:option:`norandommap` is enabled, with offset modifiers
+	(refer :option:`readwrite` and :option:`rw_sequencer`) etc verification of
+	header seed may fail. Disabling this option will mean that header seed
+	checking is skipped. Defaults to true.
+
 .. option:: trim_percentage=int
 
 	Number of verify blocks to discard/trim.
diff --git a/cconv.c b/cconv.c
index ef3fbaa8..df841703 100644
--- a/cconv.c
+++ b/cconv.c
@@ -183,6 +183,7 @@ int convert_thread_options_to_cpu(struct thread_options *o,
 	o->verify_interval = le32_to_cpu(top->verify_interval);
 	o->verify_offset = le32_to_cpu(top->verify_offset);
 	o->verify_write_sequence = le32_to_cpu(top->verify_write_sequence);
+	o->verify_header_seed = le32_to_cpu(top->verify_header_seed);
 
 	o->verify_pattern_bytes = le32_to_cpu(top->verify_pattern_bytes);
 	o->buffer_pattern_bytes = le32_to_cpu(top->buffer_pattern_bytes);
@@ -444,6 +445,7 @@ void convert_thread_options_to_net(struct thread_options_pack *top,
 	top->verify_interval = cpu_to_le32(o->verify_interval);
 	top->verify_offset = cpu_to_le32(o->verify_offset);
 	top->verify_write_sequence = cpu_to_le32(o->verify_write_sequence);
+	top->verify_header_seed = cpu_to_le32(o->verify_header_seed);
 	top->verify_pattern_bytes = cpu_to_le32(o->verify_pattern_bytes);
 	top->verify_fatal = cpu_to_le32(o->verify_fatal);
 	top->verify_dump = cpu_to_le32(o->verify_dump);
diff --git a/fio.1 b/fio.1
index 88d3be81..dd6d9546 100644
--- a/fio.1
+++ b/fio.1
@@ -3554,8 +3554,9 @@ If writing to a file, fio can verify the file contents after each iteration
 of the job. Each verification method also implies verification of special
 header, which is written to the beginning of each block. This header also
 includes meta information, like offset of the block, block number, timestamp
-when block was written, etc. \fBverify\fR can be combined with
-\fBverify_pattern\fR option. The allowed values are:
+when block was written, initial seed value used to generate the buffer
+contents, etc. \fBverify\fR can be combined with \fBverify_pattern\fR option.
+The allowed values are:
 .RS
 .RS
 .TP
@@ -3751,6 +3752,13 @@ 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 verify_header_seed \fR=\fPbool
+Verify the header seed value which was used to generate the buffer contents.
+In certain scenarios with read / verify only workloads, when \fBnorandommap\fR
+is enabled, with offset modifiers (refer options \fBreadwrite\fR and
+\fBrw_sequencer\fR), etc verification of header seed may fail. Disabling this
+option will mean that header seed checking is skipped. Defaults to true.
+.TP
 .BI trim_percentage \fR=\fPint
 Number of verify blocks to discard/trim.
 .TP
diff --git a/options.c b/options.c
index c35878f7..416bc91c 100644
--- a/options.c
+++ b/options.c
@@ -3408,6 +3408,17 @@ struct fio_option fio_options[FIO_MAX_OPTS] = {
 		.category = FIO_OPT_C_IO,
 		.group	= FIO_OPT_G_VERIFY,
 	},
+	{
+		.name	= "verify_header_seed",
+		.lname	= "Verify header seed",
+		.off1	= offsetof(struct thread_options, verify_header_seed),
+		.type	= FIO_OPT_BOOL,
+		.def	= "1",
+		.help	= "Verify the header seed used to generate the buffer contents",
+		.parent	= "verify",
+		.category = FIO_OPT_C_IO,
+		.group	= FIO_OPT_G_VERIFY,
+	},
 #ifdef FIO_HAVE_TRIM
 	{
 		.name	= "trim_percentage",
diff --git a/server.h b/server.h
index d31cd688..e5968112 100644
--- a/server.h
+++ b/server.h
@@ -51,7 +51,7 @@ struct fio_net_cmd_reply {
 };
 
 enum {
-	FIO_SERVER_VER			= 108,
+	FIO_SERVER_VER			= 109,
 
 	FIO_SERVER_MAX_FRAGMENT_PDU	= 1024,
 	FIO_SERVER_MAX_CMD_MB		= 2048,
diff --git a/thread_options.h b/thread_options.h
index 4d8addc4..d25ba891 100644
--- a/thread_options.h
+++ b/thread_options.h
@@ -157,6 +157,7 @@ struct thread_options {
 	unsigned int verify_state;
 	unsigned int verify_state_save;
 	unsigned int verify_write_sequence;
+	unsigned int verify_header_seed;
 	unsigned int use_thread;
 	unsigned int unlink;
 	unsigned int unlink_each_loop;
@@ -485,7 +486,7 @@ struct thread_options_pack {
 	uint32_t verify_state;
 	uint32_t verify_state_save;
 	uint32_t verify_write_sequence;
-	uint32_t pad2;
+	uint32_t verify_header_seed;
 	uint32_t use_thread;
 	uint32_t unlink;
 	uint32_t unlink_each_loop;
diff --git a/verify.c b/verify.c
index 570c888f..49d44982 100644
--- a/verify.c
+++ b/verify.c
@@ -833,7 +833,7 @@ static int verify_header(struct io_u *io_u, struct thread_data *td,
 			hdr->len, hdr_len);
 		goto err;
 	}
-	if (hdr->rand_seed != io_u->rand_seed) {
+	if (td->o.verify_header_seed && (hdr->rand_seed != io_u->rand_seed)) {
 		log_err("verify: bad header rand_seed %"PRIu64
 			", wanted %"PRIu64,
 			hdr->rand_seed, io_u->rand_seed);
-- 
2.25.1