On Fri, Sep 29, 2017 at 08:00:34AM -0500, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
>
> This allows to make pwritev2() calls with RWF_NOWAIT,
> which would fail in case the call blocks.
>
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
> ---
> io/pwrite.c | 8 +++++++-
> man/man8/xfs_io.8 | 6 ++++++
> 2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/io/pwrite.c b/io/pwrite.c
> index e7d411bb..2b85a528 100644
> --- a/io/pwrite.c
> +++ b/io/pwrite.c
> @@ -52,6 +52,9 @@ pwrite_help(void)
> " (heh, zorry, the -s/-S arguments were already in use in pwrite)\n"
> #ifdef HAVE_PWRITEV
> " -V N -- use vectored IO with N iovecs of blocksize each (pwritev)\n"
> +#ifdef HAVE_PWRITEV2
> +" -N -- Perform the pwritev2() with RWF_NOWAIT\n"
> +#endif
Separate these two? i.e.
#ifdef HAVE_PWRITEV
" -V N..."
#endif
#ifdef HAVE_PWRITEV2
" -N ..."
#endif
They're tested separately in configure, so the ifdefs needn't be nested.
> #endif
> "\n"));
> }
> @@ -276,7 +279,7 @@ 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);
> @@ -305,6 +308,9 @@ pwrite_f(
> case 'i':
> infile = optarg;
> break;
> + case 'N':
> + pwritev2_flags |= RWF_NOWAIT;
> + break;
Needs #ifdef HAVE_PWRITEV2.
If you feel the need to be extra cautious, you could also put:
#ifndef HAVE_PWRITEV2
assert(pwritev2_flags == 0);
#endif
...just after the getopt parsing to make sure that we never silently
drop RWF_* flags due to code bugs.
--D
> case 's':
> skip = cvtnum(fsblocksize, fssectsize, optarg);
> if (skip < 0) {
> diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
> index 0fd9b951..9c58914f 100644
> --- a/man/man8/xfs_io.8
> +++ b/man/man8/xfs_io.8
> @@ -282,6 +282,12 @@ Use the vectored IO write syscall
> with a number of blocksize length iovecs. The number of iovecs is set by the
> .I vectors
> parameter.
> +.TP
> +.B \-N
> +Perform the
> +.BR pwritev2 (2)
> +call with
> +.I RWF_NOWAIT.
> .RE
> .PD
> .TP
> --
> 2.14.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
