Add per-io RWF_DONTCACHE support flag to pwritev2().
This enables xfs_io to perform uncached buffered-io writes.
e.g. xfs_io -fc "pwrite -U -V 1 0 16K" /mnt/f1
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
---
include/linux.h | 5 +++++
io/pwrite.c | 14 ++++++++++++--
man/man8/xfs_io.8 | 8 +++++++-
3 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/include/linux.h b/include/linux.h
index b3516d54..6e83e073 100644
--- a/include/linux.h
+++ b/include/linux.h
@@ -237,6 +237,11 @@ struct fsxattr {
#define RWF_ATOMIC ((__kernel_rwf_t)0x00000040)
#endif
+/* buffered IO that drops the cache after reading or writing data */
+#ifndef RWF_DONTCACHE
+#define RWF_DONTCACHE ((__kernel_rwf_t)0x00000080)
+#endif
+
/*
* Reminder: anything added to this file will be compiled into downstream
* userspace projects!
diff --git a/io/pwrite.c b/io/pwrite.c
index fab59be4..5fb0253f 100644
--- a/io/pwrite.c
+++ b/io/pwrite.c
@@ -45,6 +45,7 @@ pwrite_help(void)
" -N -- Perform the pwritev2() with RWF_NOWAIT\n"
" -D -- Perform the pwritev2() with RWF_DSYNC\n"
" -A -- Perform the pwritev2() with RWF_ATOMIC\n"
+" -U -- Perform the pwritev2() with Uncached/RWF_DONTCACHE\n"
#endif
"\n"));
}
@@ -285,7 +286,7 @@ pwrite_f(
init_cvtnum(&fsblocksize, &fssectsize);
bsize = fsblocksize;
- while ((c = getopt(argc, argv, "Ab:BCdDf:Fi:NqRs:OS:uV:wWZ:")) != EOF) {
+ while ((c = getopt(argc, argv, "Ab:BCdDf:Fi:NqRs:OS:uUV:wWZ:")) != EOF) {
switch (c) {
case 'b':
tmp = cvtnum(fsblocksize, fssectsize, optarg);
@@ -328,6 +329,9 @@ pwrite_f(
case 'A':
pwritev2_flags |= RWF_ATOMIC;
break;
+ case 'U':
+ pwritev2_flags |= RWF_DONTCACHE;
+ break;
#endif
case 's':
skip = cvtnum(fsblocksize, fssectsize, optarg);
@@ -392,6 +396,12 @@ pwrite_f(
exitcode = 1;
return command_usage(&pwrite_cmd);
}
+ if (pwritev2_flags != 0 && vectors == 0) {
+ printf(_("pwritev2 flags require vectored I/O (-V)\n"));
+ exitcode = 1;
+ return command_usage(&pwrite_cmd);
+ }
+
offset = cvtnum(fsblocksize, fssectsize, argv[optind]);
if (offset < 0) {
printf(_("non-numeric offset argument -- %s\n"), argv[optind]);
@@ -480,7 +490,7 @@ pwrite_init(void)
pwrite_cmd.argmax = -1;
pwrite_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
pwrite_cmd.args =
-_("[-i infile [-qAdDwNOW] [-s skip]] [-b bs] [-S seed] [-FBR [-Z N]] [-V N] off len");
+_("[-i infile [-qAdDwNOUW] [-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 59d5ddc5..47af5232 100644
--- a/man/man8/xfs_io.8
+++ b/man/man8/xfs_io.8
@@ -244,7 +244,7 @@ See the
.B pread
command.
.TP
-.BI "pwrite [ \-i " file " ] [ \-qAdDwNOW ] [ \-s " skip " ] [ \-b " size " ] [ \-S " seed " ] [ \-FBR [ \-Z " zeed " ] ] [ \-V " vectors " ] " "offset length"
+.BI "pwrite [ \-i " file " ] [ \-qAdDwNOUW ] [ \-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
@@ -287,6 +287,12 @@ Perform the
call with
.IR RWF_ATOMIC .
.TP
+.B \-U
+Perform the
+.BR pwritev2 (2)
+call with
+.IR RWF_DONTCACHE .
+.TP
.B \-O
perform pwrite once and return the (maybe partial) bytes written.
.TP
--
2.48.1
