Add splice command into xfs_io, by calling splice(2) system call.
Signed-off-by: Zorro Lang <zlang@xxxxxxxxxx>
---
Hi,
I've add splice() test into fsstress.c, due to we find a XFS regression
by doing some splice test on overlayfs over XFS. Although copy_file_range
maybe through splice() code path, but it depends. So a specified splice
operation is helpful to use splice clearly.
Thanks,
Zorro
io/Makefile | 2 +-
io/init.c | 1 +
io/io.h | 1 +
io/splice.c | 194 ++++++++++++++++++++++++++++++++++++++++++++++
man/man8/xfs_io.8 | 26 +++++++
5 files changed, 223 insertions(+), 1 deletion(-)
create mode 100644 io/splice.c
diff --git a/io/Makefile b/io/Makefile
index 484e2b5a..06d21dd5 100644
--- a/io/Makefile
+++ b/io/Makefile
@@ -12,7 +12,7 @@ CFILES = init.c \
attr.c bmap.c crc32cselftest.c cowextsize.c encrypt.c file.c freeze.c \
fsync.c getrusage.c imap.c inject.c label.c link.c mmap.c open.c \
parent.c pread.c prealloc.c pwrite.c reflink.c resblks.c scrub.c \
- seek.c shutdown.c stat.c swapext.c sync.c truncate.c utimes.c
+ seek.c shutdown.c splice.c stat.c swapext.c sync.c truncate.c utimes.c
LLDLIBS = $(LIBXCMD) $(LIBHANDLE) $(LIBFROG) $(LIBPTHREAD)
LTDEPENDENCIES = $(LIBXCMD) $(LIBHANDLE) $(LIBFROG)
diff --git a/io/init.c b/io/init.c
index 83f08f2d..fc191aa7 100644
--- a/io/init.c
+++ b/io/init.c
@@ -79,6 +79,7 @@ init_commands(void)
seek_init();
sendfile_init();
shutdown_init();
+ splice_init();
stat_init();
swapext_init();
sync_init();
diff --git a/io/io.h b/io/io.h
index 6469179e..9a0b71f0 100644
--- a/io/io.h
+++ b/io/io.h
@@ -110,6 +110,7 @@ extern void quit_init(void);
extern void resblks_init(void);
extern void seek_init(void);
extern void shutdown_init(void);
+extern void splice_init(void);
extern void stat_init(void);
extern void swapext_init(void);
extern void sync_init(void);
diff --git a/io/splice.c b/io/splice.c
new file mode 100644
index 00000000..7e2f1aa2
--- /dev/null
+++ b/io/splice.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Red Hat, Inc.
+ * All Rights Reserved.
+ */
+
+#include "command.h"
+#include "input.h"
+#include <fcntl.h>
+#include "init.h"
+#include "io.h"
+
+static cmdinfo_t splice_cmd;
+
+static void
+splice_help(void)
+{
+ printf(_(
+"\n"
+" Splice a range of bytes from the given offset between files through pipe\n"
+"\n"
+" Example:\n"
+" 'splice filename 0 4096 32768' - splice 32768 bytes from filename at offset\n"
+" 0 into the open file at position 4096\n"
+" 'splice filename' - splice all bytes from filename into the open file at\n"
+" ' position 0\n"
+"\n"
+" Copies data between one file and another. Because this copying is done\n"
+" within the kernel, sendfile does not need to transfer data to and from user\n"
+" space.\n"
+" -m -- SPLICE_F_MOVE flag, attempt to move pages instead of copying.\n"
+" Offset and length in the source/destination file can be optionally specified.\n"
+"\n"));
+}
+
+static uint64_t
+splice_file(
+ int fd,
+ off64_t soffset,
+ off64_t doffset,
+ size_t length,
+ unsigned int flag,
+ int *ops)
+{
+ off64_t soff = soffset;
+ off64_t doff = doffset;
+ ssize_t rc = 0;
+ size_t len = length;
+ uint64_t total = 0;
+ int filedes[2];
+
+ if (pipe(filedes) < 0) {
+ perror("pipe");
+ return -1;
+ }
+
+ *ops = 0;
+ while (len > 0 || !*ops) {
+ /* move to pipe buffer */
+ rc = splice(fd, &soff, filedes[1], NULL, len, flag);
+ if (rc < 0) {
+ perror("splice to pipe");
+ goto out_close;
+ }
+ /* move from pipe buffer to dst file */
+ rc = splice(filedes[0], NULL, file->fd, &doff, len, flag);
+ if (rc < 0) {
+ perror("splice from pipe");
+ goto out_close;
+ }
+ (*ops)++;
+ len -= rc;
+ total += rc;
+ }
+
+out_close:
+ close(filedes[0]);
+ close(filedes[1]);
+ return total;
+}
+
+static int
+splice_f(
+ int argc,
+ char **argv)
+{
+ off64_t soffset, doffset;
+ long long count, total;
+ size_t blocksize, sectsize;
+ struct timeval t1, t2;
+ char *infile = NULL;
+ int Cflag, qflag;
+ int splice_flag = 0;
+ int c, fd = -1;
+ int ops = 0;
+
+ Cflag = qflag = 0;
+ soffset = doffset=0;
+ init_cvtnum(&blocksize, §size);
+
+ while ((c = getopt(argc, argv, "Cqm")) != EOF) {
+ switch (c) {
+ case 'C':
+ Cflag = 1;
+ break;
+ case 'q':
+ qflag = 1;
+ break;
+ case 'm':
+ splice_flag |= SPLICE_F_MOVE;
+ break;
+ default:
+ return command_usage(&splice_cmd);
+ }
+ }
+
+ if (optind != argc - 4 && optind != argc - 1)
+ return command_usage(&splice_cmd);
+
+ infile = argv[optind];
+ if ((fd = openfile(infile, NULL, IO_READONLY, 0, NULL)) < 0)
+ return 0;
+ optind++;
+
+ if (optind == argc - 3) {
+ soffset = cvtnum(blocksize, sectsize, argv[optind]);
+ if (soffset < 0) {
+ printf(_("non-numeric src offset argument -- %s\n"), \
+ argv[optind]);
+ return 0;
+ }
+ optind++;
+ doffset = cvtnum(blocksize, sectsize, argv[optind]);
+ if (doffset < 0) {
+ printf(_("non-numeric dest offset argument -- %s\n"), \
+ argv[optind]);
+ return 0;
+ }
+ optind++;
+ count = cvtnum(blocksize, sectsize, argv[optind]);
+ if (count < 0) {
+ printf(_("non-positive length argument -- %s\n"), \
+ argv[optind]);
+ return 0;
+ }
+ } else {
+ /*
+ * splice whole file to another, if doesn't specify src and dst
+ * offset and length
+ */
+ struct stat stat;
+
+ if (fstat(fd, &stat) < 0) {
+ perror("fstat");
+ goto done;
+ }
+ count = stat.st_size;
+ soffset = 0;
+ doffset = 0;
+ }
+
+ gettimeofday(&t1, NULL);
+ total = splice_file(fd, soffset, doffset, count, splice_flag, &ops);
+ if (ops == 0 || qflag)
+ goto done;
+ gettimeofday(&t2, NULL);
+ t2 = tsub(t2, t1);
+
+ report_io_times("spliced", &t2, (long long)doffset, count, total, ops, \
+ Cflag);
+
+done:
+ if (infile)
+ close(fd);
+ return 0;
+}
+
+void
+splice_init(void)
+{
+ splice_cmd.name = "splice";
+ splice_cmd.altname = "spl";
+ splice_cmd.cfunc = splice_f;
+ splice_cmd.argmin = 1;
+ splice_cmd.argmax = -1;
+ splice_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK | CMD_FLAG_ONESHOT;;
+ splice_cmd.args =
+ _("[-m] infile [src_off dst_off len]");
+ splice_cmd.oneline =
+ _("Splice an entire file, or a number of bytes at a specified offset");
+ splice_cmd.help = splice_help;
+
+ add_command(&splice_cmd);
+}
diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
index 980dcfd3..066a72e7 100644
--- a/man/man8/xfs_io.8
+++ b/man/man8/xfs_io.8
@@ -830,6 +830,32 @@ verbose output will be printed.
.RE
.PD
.TP
+.BI "splice [ \-C ] [ \-q ] [\-m] infile [src_offset dst_offset length]"
+On filesystems that support the
+.BR splice (2)
+system call, splice data from the
+.I infile
+into the open file. If
+.IR src_offset ,
+.IR dst_offset ,
+and
+.I length
+are omitted the contents of infile will be copied to the beginning of the
+open file, overwriting any data already there.
+.RS 1.0i
+.PD 0
+.TP 0.4i
+.B \-C
+Print timing statistics in a condensed format.
+.TP
+.B \-q
+Do not print timing statistics at all.
+.TP
+.B \-m
+Enable SPLICE_F_MOVE flag, attempt to move pages instead of copying.
+.RE
+.PD
+.TP
.BI utimes " atime_sec atime_nsec mtime_sec mtime_nsec"
The utimes command changes the atime and mtime of the current file.
sec uses UNIX timestamp notation and is the seconds elapsed since
--
2.17.2
