Recent changes (master)

[Jens Axboe <axboe@kernel.dk>]

The following changes since commit acb7a302059b0cc397c95a232a44cb14c524bbde:

  Merge branch 'dmabuf-io_uringv1' of https://github.com/swarnagh6/fio (2026-10-12 19:21:58 -0400)

are available in the Git repository at:

  git://git.kernel.dk/fio.git master

for you to fetch changes up to 4767beef328a257c4300358ffa2901f3e0f1dc68:

  Merge branch 'write_zeries' of https://github.com/panky-codes/fio (2026-10-19 11:57:14 -0400)

----------------------------------------------------------------
Pankaj Raghav (1):
      fio: add FALLOC_FL_WRITE_ZEROES support to falloc

Vincent Fu (1):
      Merge branch 'write_zeries' of https://github.com/panky-codes/fio

 HOWTO.rst   |  8 ++++++--
 configure   | 23 +++++++++++++++++++++++
 file.h      |  3 ++-
 filesetup.c | 15 +++++++++++++++
 fio.1       |  8 ++++++--
 options.c   |  6 ++++++
 6 files changed, 58 insertions(+), 5 deletions(-)

---

Diff of recent changes:

diff --git a/HOWTO.rst b/HOWTO.rst
index 0b39b01a..6adea4d7 100644
--- a/HOWTO.rst
+++ b/HOWTO.rst
@@ -1357,6 +1357,10 @@ I/O type
 			Pre-allocate via :manpage:`fallocate(2)` with
 			FALLOC_FL_KEEP_SIZE set.
 
+		**write_zeroes**
+			Pre-allocate via :manpage:`fallocate(2)` with
+			FALLOC_FL_WRITE_ZEROES set.
+
 		**truncate**
 			Extend file to final size via :manpage:`ftruncate(2)`
 			instead of allocating.
@@ -1367,8 +1371,8 @@ I/O type
 		**1**
 			Backward-compatible alias for **posix**.
 
-	May not be available on all supported platforms. **keep** is only available
-	on Linux. If using ZFS on Solaris this cannot be set to **posix**
+	May not be available on all supported platforms. **keep** and
+	**write_zeroes** are only available on Linux. If using ZFS on Solaris this cannot be set to **posix**
 	because ZFS doesn't support pre-allocation. Default: **native** if any
 	pre-allocation methods except **truncate** are available, **none** if not.
 
diff --git a/configure b/configure
index 60d0ef98..9dfc9b6d 100755
--- a/configure
+++ b/configure
@@ -1098,6 +1098,26 @@ if compile_prog "" "" "linux_fallocate"; then
 fi
 print_config "Linux fallocate" "$linux_fallocate"
 
+##########################################
+# Linux fallocate FALLOC_FL_WRITE_ZEROES probe
+if test "$linux_fallocate_write_zeroes" != "yes" ; then
+  linux_fallocate_write_zeroes="no"
+fi
+cat > $TMPC << EOF
+#include <stdio.h>
+#include <fcntl.h>
+#include <linux/falloc.h>
+int main(int argc, char **argv)
+{
+  int r = fallocate(0, FALLOC_FL_WRITE_ZEROES, 0, 1024);
+  return r;
+}
+EOF
+if compile_prog "" "" "linux_fallocate_write_zeroes"; then
+    linux_fallocate_write_zeroes="yes"
+fi
+print_config "Linux fallocate write zeroes" "$linux_fallocate_write_zeroes"
+
 ##########################################
 # POSIX fadvise probe
 if test "$posix_fadvise" != "yes" ; then
@@ -3221,6 +3241,9 @@ fi
 if test "$linux_fallocate" = "yes" ; then
   output_sym "CONFIG_LINUX_FALLOCATE"
 fi
+if test "$linux_fallocate_write_zeroes" = "yes" ; then
+  output_sym "CONFIG_LINUX_FALLOCATE_WRITE_ZEROES"
+fi
 if test "$posix_fallocate" = "yes" ; then
   output_sym "CONFIG_POSIX_FALLOCATE"
 fi
diff --git a/file.h b/file.h
index 6fcf409b..d3375d7c 100644
--- a/file.h
+++ b/file.h
@@ -63,7 +63,7 @@ enum {
 
 /*
  * No pre-allocation when laying down files, or call posix_fallocate(), or
- * call fallocate() with FALLOC_FL_KEEP_SIZE set.
+ * call fallocate() with FALLOC_FL_KEEP_SIZE or FALLOC_FL_WRITE_ZEROES set.
  */
 enum fio_fallocate_mode {
 	FIO_FALLOCATE_NONE	= 1,
@@ -71,6 +71,7 @@ enum fio_fallocate_mode {
 	FIO_FALLOCATE_KEEP_SIZE	= 3,
 	FIO_FALLOCATE_NATIVE	= 4,
 	FIO_FALLOCATE_TRUNCATE	= 5,
+	FIO_FALLOCATE_WRITE_ZEROES = 6,
 };
 
 /*
diff --git a/filesetup.c b/filesetup.c
index 72be2591..0f8c4d74 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -95,6 +95,21 @@ static void fallocate_file(struct thread_data *td, struct fio_file *f)
 
 		break;
 		}
+#ifdef CONFIG_LINUX_FALLOCATE_WRITE_ZEROES
+	case FIO_FALLOCATE_WRITE_ZEROES: {
+		int r;
+
+		dprint(FD_FILE, "fallocate(FALLOC_FL_WRITE_ZEROES) "
+				"file %s size %llu\n", f->file_name,
+				(unsigned long long) f->real_file_size);
+
+		r = fallocate(f->fd, FALLOC_FL_WRITE_ZEROES, 0, f->real_file_size);
+		if (r != 0)
+			td_verror(td, errno, "fallocate");
+
+		break;
+		}
+#endif /* CONFIG_LINUX_FALLOCATE_WRITE_ZEROES */
 #endif /* CONFIG_LINUX_FALLOCATE */
 	case FIO_FALLOCATE_TRUNCATE: {
 		int r;
diff --git a/fio.1 b/fio.1
index 08153d30..6123b8d3 100644
--- a/fio.1
+++ b/fio.1
@@ -1139,6 +1139,10 @@ Pre-allocate via \fBposix_fallocate\fR\|(3).
 Pre-allocate via \fBfallocate\fR\|(2) with
 FALLOC_FL_KEEP_SIZE set.
 .TP
+.B write_zeroes
+Pre-allocate via \fBfallocate\fR\|(2) with
+FALLOC_FL_WRITE_ZEROES set.
+.TP
 .B truncate
 Extend file to final size using \fBftruncate\fR|(2)
 instead of allocating.
@@ -1150,8 +1154,8 @@ Backward-compatible alias for \fBnone\fR.
 Backward-compatible alias for \fBposix\fR.
 .RE
 .P
-May not be available on all supported platforms. \fBkeep\fR is only available
-on Linux. If using ZFS on Solaris this cannot be set to \fBposix\fR
+May not be available on all supported platforms. \fBkeep\fR and
+\fBwrite_zeroes\fR are only available on Linux. If using ZFS on Solaris this cannot be set to \fBposix\fR
 because ZFS doesn't support pre-allocation. Default: \fBnative\fR if any
 pre-allocation methods except \fBtruncate\fR are available, \fBnone\fR if not.
 .P
diff --git a/options.c b/options.c
index bb7296ed..e707203d 100644
--- a/options.c
+++ b/options.c
@@ -3011,6 +3011,12 @@ struct fio_option fio_options[FIO_MAX_OPTS] = {
 			    .oval = FIO_FALLOCATE_KEEP_SIZE,
 			    .help = "Use fallocate(..., FALLOC_FL_KEEP_SIZE, ...)",
 			  },
+#ifdef CONFIG_LINUX_FALLOCATE_WRITE_ZEROES
+			  { .ival = "write_zeroes",
+			    .oval = FIO_FALLOCATE_WRITE_ZEROES,
+			    .help = "Use fallocate(..., FALLOC_FL_WRITE_ZEROES, ...)",
+			  },
+#endif
 #endif
 			  { .ival = "truncate",
 			    .oval = FIO_FALLOCATE_TRUNCATE,