From 0799d5cf54dcfe9579268b644c6f5706fc341e93 Mon Sep 17 00:00:00 2001
From: Goldwyn Rodrigues <rgoldwyn@suse.com>
Date: Thu, 9 Nov 2017 14:56:28 -0600
Subject: [PATCH] xfs_io: Add RWF_NOWAIT to pwritev2()

This allows to make pwritev2() calls with RWF_NOWAIT,
which would fail in case the call blocks.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
[sandeen@sandeen.net: combine all optional args in short help]
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---
 io/pwrite.c       | 12 ++++++++++--
 man/man8/xfs_io.8 | 28 +++++++++++++++++-----------
 2 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/io/pwrite.c b/io/pwrite.c
index abd3a184d..c36a661a8 100644
--- a/io/pwrite.c
+++ b/io/pwrite.c
@@ -53,6 +53,9 @@ pwrite_help(void)
 #ifdef HAVE_PWRITEV
 " -V N -- use vectored IO with N iovecs of blocksize each (pwritev)\n"
 #endif
+#ifdef HAVE_PWRITEV2
+" -N   -- Perform the pwritev2() with RWF_NOWAIT\n"
+#endif
 "\n"));
 }
 
@@ -279,7 +282,7 @@ pwrite_f(
 	init_cvtnum(&fsblocksize, &fssectsize);
 	bsize = fsblocksize;
 
-	while ((c = getopt(argc, argv, "b:BCdf:Fi:qRs:S:uV:wWZ:")) != EOF) {
+	while ((c = getopt(argc, argv, "b:BCdf:Fi:NqRs:S:uV:wWZ:")) != EOF) {
 		switch (c) {
 		case 'b':
 			tmp = cvtnum(fsblocksize, fssectsize, optarg);
@@ -308,6 +311,11 @@ pwrite_f(
 		case 'i':
 			infile = optarg;
 			break;
+#ifdef HAVE_PWRITEV2
+		case 'N':
+			pwritev2_flags |= RWF_NOWAIT;
+			break;
+#endif
 		case 's':
 			skip = cvtnum(fsblocksize, fssectsize, optarg);
 			if (skip < 0) {
@@ -438,7 +446,7 @@ pwrite_init(void)
 	pwrite_cmd.argmax = -1;
 	pwrite_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
 	pwrite_cmd.args =
-_("[-i infile [-d] [-s skip]] [-b bs] [-S seed] [-wW] [-FBR [-Z N]] [-V N] off len");
+_("[-i infile [-dwNW] [-s skip]] [-b bs] [-S seed] [-FBR [-Z N]] [-V N] off len");
 	pwrite_cmd.oneline =
 		_("writes a number of bytes at a specified offset");
 	pwrite_cmd.help = pwrite_help;
diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
index 0fd9b9511..c2fe6aae7 100644
--- a/man/man8/xfs_io.8
+++ b/man/man8/xfs_io.8
@@ -222,7 +222,7 @@ See the
 .B pread
 command.
 .TP
-.BI "pwrite [ \-i " file " ] [ \-d ] [ \-s " skip " ] [ \-b " size " ] [ \-S " seed " ] [ \-FBR [ \-Z " zeed " ] ] [ \-wW ] [ \-V " vectors " ] " "offset length"
+.BI "pwrite [ \-i " file " ] [ \-dwNW ] [ \-s " skip " ] [ \-b " size " ] [ \-S " seed " ] [ \-FBR [ \-Z " zeed " ] ] [ \-V " vectors " ] " "offset length"
 Writes a range of bytes in a specified blocksize from the given
 .IR offset .
 The bytes written can be either a set pattern or read in from another
@@ -239,6 +239,22 @@ to be specified as the source of the data to be written.
 causes direct I/O, rather than the usual buffered
 I/O, to be used when reading the input file.
 .TP
+.B \-w
+call
+.BR fdatasync (2)
+once all writes are complete (included in timing results)
+.TP
+.B \-N
+Perform the
+.BR pwritev2 (2)
+call with
+.I RWF_NOWAIT.
+.TP
+.B \-W
+call
+.BR fsync (2)
+once all writes are complete (included in timing results)
+.TP
 .B \-s
 specifies the number of bytes to
 .I skip
@@ -266,16 +282,6 @@ write the buffers in the give range in a random order.
 .B \-Z seed
 specify the random number seed used for random write
 .TP
-.B \-w
-call
-.BR fdatasync (2)
-once all writes are complete (included in timing results)
-.TP
-.B \-W
-call
-.BR fsync (2)
-once all writes are complete (included in timing results)
-.TP
 .B \-V vectors
 Use the vectored IO write syscall
 .BR pwritev (2)
-- 
2.47.2