On 9/6/19 12:02 PM, Jianhong.Yin wrote: > 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 > > and have confirmed that this change will not affect xfstests. > > Signed-off-by: Jianhong Yin <yin-jianhong@xxxxxxx> > --- > io/copy_file_range.c | 22 +++++----------------- > man/man8/xfs_io.8 | 12 ++++++------ > 2 files changed, 11 insertions(+), 23 deletions(-) > > diff --git a/io/copy_file_range.c b/io/copy_file_range.c > index b7b9fd88..2bc8494e 100644 > --- a/io/copy_file_range.c > +++ b/io/copy_file_range.c > @@ -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; I'd like to change these to src_off & dst_off, just to help keep track of things. > size_t len = 0; > + bool len_specified = false; > int opt; > int ret; > int fd; > @@ -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) { normal xfsprogs style is no space after the ! > off64_t sz; > > sz = copy_src_filesize(fd); > @@ -145,13 +138,8 @@ 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) > + len = sz - src; Ok, so if source offset is past EOF, we keep len = 0. Looks like the kernel does that internally too, so no problem there. I'll make the cosmetic changes I mentioned above when I commit it, unless you have any concerns about that. /* Shorten the copy to EOF */ size_in = i_size_read(inode_in); if (pos_in >= size_in) count = 0; Reviewed-by: Eric Sandeen <sandeen@xxxxxxxxxx> > } > > ret = copy_file_range_cmd(fd, &src, &dst, len); > 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 >
