This is for doing empty file creation jobs much like what we do with
fs_mark. You still need to specify a filesize so that fio will pretend
to do something, but the IO won't actually be done on the file.
Signed-off-by: Josef Bacik <jbacik@xxxxxx>
---
HOWTO | 4 +++
Makefile | 2 +-
engines/filecreate.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++
fio.1 | 4 +++
4 files changed, 98 insertions(+), 1 deletion(-)
create mode 100644 engines/filecreate.c
diff --git a/HOWTO b/HOWTO
index 8fad2ce6f4d8..df79e2dffb30 100644
--- a/HOWTO
+++ b/HOWTO
@@ -1797,6 +1797,10 @@ I/O engine
absolute or relative. See :file:`engines/skeleton_external.c` for
details of writing an external I/O engine.
+ **filecreate**
+ Simply create the files and do no IO to them. You still need to
+ set `filesize` so that all the accounting still occurs, but no
+ actual IO will be done other than creating the file.
I/O engine specific parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/Makefile b/Makefile
index 3764da550851..76243ffb056e 100644
--- a/Makefile
+++ b/Makefile
@@ -42,7 +42,7 @@ SOURCE := $(sort $(patsubst $(SRCDIR)/%,%,$(wildcard $(SRCDIR)/crc/*.c)) \
eta.c verify.c memory.c io_u.c parse.c mutex.c options.c \
smalloc.c filehash.c profile.c debug.c engines/cpu.c \
engines/mmap.c engines/sync.c engines/null.c engines/net.c \
- engines/ftruncate.c \
+ engines/ftruncate.c engines/filecreate.c \
server.c client.c iolog.c backend.c libfio.c flow.c cconv.c \
gettime-thread.c helpers.c json.c idletime.c td_error.c \
profiles/tiobench.c profiles/act.c io_u_queue.c filelock.c \
diff --git a/engines/filecreate.c b/engines/filecreate.c
new file mode 100644
index 000000000000..284aaf398328
--- /dev/null
+++ b/engines/filecreate.c
@@ -0,0 +1,89 @@
+/*
+ * filecreate engine
+ *
+ * IO engine that doesn't do any IO, just creates files and tracks the latency
+ * of the file creation.
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include "../fio.h"
+#include "../filehash.h"
+
+static int open_file(struct thread_data *td, struct fio_file *f)
+{
+ struct timespec start, end;
+ int from_hash = 0;
+ int do_lat = !td->o.disable_lat;
+
+ dprint(FD_FILE, "fd open %s\n", f->file_name);
+
+ if (f->filetype != FIO_TYPE_FILE) {
+ log_err("fio: only files are supported fallocate \n");
+ return 1;
+ }
+ if (!strcmp(f->file_name, "-")) {
+ log_err("fio: can't read/write to stdin/out\n");
+ return 1;
+ }
+
+open_again:
+ if (do_lat)
+ fio_gettime(&start, NULL);
+ from_hash = file_lookup_open(f, O_CREAT|O_RDWR);
+ if (do_lat) {
+ unsigned long long nsec;
+
+ fio_gettime(&end, NULL);
+ nsec = ntime_since(&start, &end);
+ add_lat_sample(td, DDIR_WRITE, nsec, 0, 0);
+ }
+
+ if (f->fd == -1) {
+ char buf[FIO_VERROR_SIZE];
+ int e = errno;
+
+ snprintf(buf, sizeof(buf), "open(%s)", f->file_name);
+ td_verror(td, e, buf);
+ }
+
+ if (!from_hash && f->fd != -1) {
+ if (add_file_hash(f)) {
+ int fio_unused ret;
+
+ /*
+ * OK to ignore, we haven't done anything with it
+ */
+ ret = generic_close_file(td, f);
+ goto open_again;
+ }
+ }
+
+ return 0;
+}
+
+static int queue_io(struct thread_data *td, struct io_u fio_unused *io_u)
+{
+ return FIO_Q_COMPLETED;
+}
+
+static struct ioengine_ops ioengine = {
+ .name = "filecreate",
+ .version = FIO_IOOPS_VERSION,
+ .open_file = open_file,
+ .queue = queue_io,
+ .close_file = generic_close_file,
+ .flags = FIO_DISKLESSIO | FIO_SYNCIO | FIO_FAKEIO,
+};
+
+static void fio_init fio_filecreate_register(void)
+{
+ register_ioengine(&ioengine);
+}
+
+static void fio_exit fio_filecreate_unregister(void)
+{
+ unregister_ioengine(&ioengine);
+}
diff --git a/fio.1 b/fio.1
index b943db2289d6..68ed3ba457b9 100644
--- a/fio.1
+++ b/fio.1
@@ -1577,6 +1577,10 @@ the engine filename, e.g. `ioengine=external:/tmp/foo.o' to load
ioengine `foo.o' in `/tmp'. The path can be either
absolute or relative. See `engines/skeleton_external.c' in the fio source for
details of writing an external I/O engine.
+.TP
+.B filecreate
+Create empty files only. \fBfilesize\fR still needs to be specified so that fio
+will run and grab latency results, but no IO will actually be done on the files.
.SS "I/O engine specific parameters"
In addition, there are some parameters which are only valid when a specific
\fBioengine\fR is in use. These are used identically to normal parameters,
--
2.7.4
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