From: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Date: Thu, 23 Jan 2020 16:36:32 +0000 (+0900)
Subject: engines/filestat: add "lstat" option to use lstat(2)
X-Git-Tag: fio-3.18~6^2
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=c446eff058f7b61a3eca679b7210fa85dc288212

engines/filestat: add "lstat" option to use lstat(2)

Use stat(2) by default, but lstat(2) if "lstat" bool option specified.

Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
---

diff --git a/HOWTO b/HOWTO
index 0a366168..f19f9226 100644
--- a/HOWTO
+++ b/HOWTO
@@ -2261,6 +2261,10 @@ with the caveat that when used on the command line, they must come after the
 	multiple paths exist between the client and the server or in certain loopback
 	configurations.
 
+.. option:: lstat=bool : [filestat]
+
+	Use lstat(2) to measure lookup/getattr performance. Default is 0.
+
 .. option:: readfua=bool : [sg]
 
 	With readfua option set to 1, read operations include
diff --git a/engines/filestat.c b/engines/filestat.c
index 79525934..6c87c4c2 100644
--- a/engines/filestat.c
+++ b/engines/filestat.c
@@ -11,13 +11,36 @@
 #include <sys/stat.h>
 #include <unistd.h>
 #include "../fio.h"
+#include "../optgroup.h"
 
 struct fc_data {
 	enum fio_ddir stat_ddir;
 };
 
+struct filestat_options {
+	void *pad;
+	unsigned int lstat;
+};
+
+static struct fio_option options[] = {
+	{
+		.name	= "lstat",
+		.lname	= "lstat",
+		.type	= FIO_OPT_BOOL,
+		.off1	= offsetof(struct filestat_options, lstat),
+		.help	= "Use lstat(2) to measure lookup/getattr performance",
+		.def	= "0",
+		.category = FIO_OPT_C_ENGINE,
+		.group	= FIO_OPT_G_FILESTAT,
+	},
+	{
+		.name	= NULL,
+	},
+};
+
 static int stat_file(struct thread_data *td, struct fio_file *f)
 {
+	struct filestat_options *o = td->eo;
 	struct timespec start;
 	int do_lat = !td->o.disable_lat;
 	struct stat statbuf;
@@ -37,13 +60,17 @@ static int stat_file(struct thread_data *td, struct fio_file *f)
 	if (do_lat)
 		fio_gettime(&start, NULL);
 
-	ret = stat(f->file_name, &statbuf);
+	if (o->lstat)
+		ret = lstat(f->file_name, &statbuf);
+	else
+		ret = stat(f->file_name, &statbuf);
 
 	if (ret == -1) {
 		char buf[FIO_VERROR_SIZE];
 		int e = errno;
 
-		snprintf(buf, sizeof(buf), "stat(%s)", f->file_name);
+		snprintf(buf, sizeof(buf), "%sstat(%s)",
+			o->lstat ? "l" : "", f->file_name);
 		td_verror(td, e, buf);
 		return 1;
 	}
@@ -103,6 +130,8 @@ static struct ioengine_ops ioengine = {
 	.open_file	= stat_file,
 	.flags		=  FIO_SYNCIO | FIO_FAKEIO |
 				FIO_NOSTATS | FIO_NOFILEHASH,
+	.options	= options,
+	.option_struct_size = sizeof(struct filestat_options),
 };
 
 static void fio_init fio_filestat_register(void)
diff --git a/fio.1 b/fio.1
index 05896e61..a58632b4 100644
--- a/fio.1
+++ b/fio.1
@@ -2032,6 +2032,9 @@ on the client site it will be used in the rdma_resolve_add()
 function. This can be useful when multiple paths exist between the
 client and the server or in certain loopback configurations.
 .TP
+.BI (filestat)lstat \fR=\fPbool
+Use \fBlstat\fR\|(2) to measure lookup/getattr performance. Default: 0.
+.TP
 .BI (sg)readfua \fR=\fPbool
 With readfua option set to 1, read operations include the force
 unit access (fua) flag. Default: 0.
diff --git a/optgroup.h b/optgroup.h
index 55ef5934..5789afd3 100644
--- a/optgroup.h
+++ b/optgroup.h
@@ -65,6 +65,7 @@ enum opt_category_group {
 	__FIO_OPT_G_ISCSI,
 	__FIO_OPT_G_NBD,
 	__FIO_OPT_G_IOURING,
+	__FIO_OPT_G_FILESTAT,
 	__FIO_OPT_G_NR,
 
 	FIO_OPT_G_RATE		= (1ULL << __FIO_OPT_G_RATE),
@@ -106,6 +107,7 @@ enum opt_category_group {
 	FIO_OPT_G_ISCSI         = (1ULL << __FIO_OPT_G_ISCSI),
 	FIO_OPT_G_NBD		= (1ULL << __FIO_OPT_G_NBD),
 	FIO_OPT_G_IOURING	= (1ULL << __FIO_OPT_G_IOURING),
+	FIO_OPT_G_FILESTAT	= (1ULL << __FIO_OPT_G_FILESTAT),
 };
 
 extern const struct opt_group *opt_group_from_mask(uint64_t *mask);