From: "Jianhong.Yin" <yin-jianhong@163.com>
To: linux-xfs@vger.kernel.org
Cc: jiyin@redhat.com, darrick.wong@oracle.com, sandeen@redhat.com,
"Jianhong.Yin" <yin-jianhong@163.com>
Subject: [PATCH v3] xfs_io: copy_range don't truncate dst_file, and add smart length
Date: Mon, 9 Sep 2019 15:29:03 +0800 [thread overview]
Message-ID: <20190909072903.2749-1-yin-jianhong@163.com> (raw)
1. copy_range should be a simple wrapper for copy_file_range(2)
and nothing else. and there's already -t option for truncate.
so here we remove the truncate action in copy_range.
see: https://patchwork.kernel.org/comment/22863587/#1
2. improve the default length value generation:
if -l option is omitted use the length that from src_offset to end
(src_file's size - src_offset) instead.
if src_offset is greater than file size, length is 0.
3. update manpage
4. rename var name from 'src, dst' to 'src_off, dst_off'
and have confirmed that this change will not affect xfstests.
Signed-off-by: Jianhong Yin <yin-jianhong@163.com>
---
io/copy_file_range.c | 40 ++++++++++++++--------------------------
man/man8/xfs_io.8 | 12 ++++++------
2 files changed, 20 insertions(+), 32 deletions(-)
diff --git a/io/copy_file_range.c b/io/copy_file_range.c
index b7b9fd88..c2105115 100644
--- a/io/copy_file_range.c
+++ b/io/copy_file_range.c
@@ -36,12 +36,12 @@ copy_range_help(void)
* glibc buffered copy fallback.
*/
static loff_t
-copy_file_range_cmd(int fd, long long *src, long long *dst, size_t len)
+copy_file_range_cmd(int fd, long long *src_off, long long *dst_off, size_t len)
{
loff_t ret;
do {
- ret = syscall(__NR_copy_file_range, fd, src, file->fd, dst,
+ ret = syscall(__NR_copy_file_range, fd, src_off, file->fd, dst_off,
len, 0);
if (ret == -1) {
perror("copy_range");
@@ -66,21 +66,13 @@ copy_src_filesize(int fd)
return st.st_size;
}
-static int
-copy_dst_truncate(void)
-{
- int ret = ftruncate(file->fd, 0);
- if (ret < 0)
- perror("ftruncate");
- return ret;
-}
-
static int
copy_range_f(int argc, char **argv)
{
- long long src = 0;
- long long dst = 0;
+ long long src_off = 0;
+ long long dst_off = 0;
size_t len = 0;
+ bool len_specified = false;
int opt;
int ret;
int fd;
@@ -93,15 +85,15 @@ copy_range_f(int argc, char **argv)
while ((opt = getopt(argc, argv, "s:d:l:f:")) != -1) {
switch (opt) {
case 's':
- src = cvtnum(fsblocksize, fssectsize, optarg);
- if (src < 0) {
+ src_off = cvtnum(fsblocksize, fssectsize, optarg);
+ if (src_off < 0) {
printf(_("invalid source offset -- %s\n"), optarg);
return 0;
}
break;
case 'd':
- dst = cvtnum(fsblocksize, fssectsize, optarg);
- if (dst < 0) {
+ dst_off = cvtnum(fsblocksize, fssectsize, optarg);
+ if (dst_off < 0) {
printf(_("invalid destination offset -- %s\n"), optarg);
return 0;
}
@@ -112,6 +104,7 @@ copy_range_f(int argc, char **argv)
printf(_("invalid length -- %s\n"), optarg);
return 0;
}
+ len_specified = true;
break;
case 'f':
src_file_nr = atoi(argv[1]);
@@ -137,7 +130,7 @@ copy_range_f(int argc, char **argv)
fd = filetable[src_file_nr].fd;
}
- if (src == 0 && dst == 0 && len == 0) {
+ if (!len_specified) {
off64_t sz;
sz = copy_src_filesize(fd);
@@ -145,16 +138,11 @@ copy_range_f(int argc, char **argv)
ret = 1;
goto out;
}
- len = sz;
-
- ret = copy_dst_truncate();
- if (ret < 0) {
- ret = 1;
- goto out;
- }
+ if (sz > src_off)
+ len = sz - src_off;
}
- ret = copy_file_range_cmd(fd, &src, &dst, len);
+ ret = copy_file_range_cmd(fd, &src_off, &dst_off, len);
out:
close(fd);
return ret;
diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
index 6e064bdd..61c35c8e 100644
--- a/man/man8/xfs_io.8
+++ b/man/man8/xfs_io.8
@@ -669,13 +669,13 @@ The source must be specified either by path
or as another open file
.RB ( \-f ).
If
-.I src_file
-.IR src_offset ,
-.IR dst_offset ,
-and
.I length
-are omitted the contents of src_file will be copied to the beginning of the
-open file, overwriting any data already there.
+is not specified, this command copies data from
+.I src_offset
+to the end of
+.BI src_file
+into the dst_file at
+.IR dst_offset .
.RS 1.0i
.PD 0
.TP 0.4i
--
2.21.0
next reply other threads:[~2019-09-09 7:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-09 7:29 Jianhong.Yin [this message]
2019-09-24 22:04 ` [PATCH v3] xfs_io: copy_range don't truncate dst_file, and add smart length Eric Sandeen
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