From: Vladimir Davydov <vdavydov.dev@gmail.com> To: Cyrill Gorcunov <gorcunov@gmail.com> Cc: tml <tarantool-patches@freelists.org> Subject: Re: [PATCH v2] core/coio_file: Use eio_sendfile_sync instead of a chunk mode Date: Tue, 16 Apr 2019 20:35:10 +0300 [thread overview] Message-ID: <20190416173510.4nxxdsqg7drrlnhe@esperanza> (raw) In-Reply-To: <20190415211410.20562-1-gorcunov@gmail.com> On Tue, Apr 16, 2019 at 12:14:10AM +0300, Cyrill Gorcunov wrote: > eio library provides a portable version of sendfile syscall > which works more efficient than explicit copying fileby 4K > chunks. > > Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> > --- > v2: > - Use sendfile in a cycle to address files more than 2G size > - Proper testing of large files remains opened: current CI engine > is hardly capable of managing it. I tested 200M files with manual > splitting (to make sure the offsets do really work) but for longterm > we still might need to invent something We could use an error injection to reduce the size of data fed to sendfile in one go. > - Another question which remains -- what to do with partially copied > files, neither code before the patch or after do not clean up parts > of copied data. Should not we clean it up on error path? If yes then > I'll prepare another patch on top. Nobody complained => I don't think we need to do anything about it. > > src/lib/core/coio_file.c | 26 +++++++++++--------------- > 1 file changed, 11 insertions(+), 15 deletions(-) > > diff --git a/src/lib/core/coio_file.c b/src/lib/core/coio_file.c > index c5b2db781..541e0f05a 100644 > --- a/src/lib/core/coio_file.c > +++ b/src/lib/core/coio_file.c > @@ -571,7 +571,7 @@ static void > coio_do_copyfile(eio_req *req) > { > struct coio_file_task *eio = (struct coio_file_task *)req->data; > - > + ssize_t pos, ret, left; > struct stat st; > if (stat(eio->copyfile.source, &st) < 0) { > goto error; > @@ -588,22 +588,18 @@ coio_do_copyfile(eio_req *req) > goto error_dest; > } > > - enum { COPY_FILE_BUF_SIZE = 4096 }; > - > - char buf[COPY_FILE_BUF_SIZE]; > - > - while (true) { > - ssize_t nread = fio_read(source_fd, buf, sizeof(buf)); > - if (nread < 0) > - goto error_copy; > - > - if (nread == 0) > - break; /* eof */ > - > - ssize_t nwritten = fio_writen(dest_fd, buf, nread); > - if (nwritten < 0) > + for (left = st.st_size, pos = 0; left > 0;) { st.st_size has time off_t while left has type ssize_t. They differ on 32-bit machines AFAIR. > + ret = eio_sendfile_sync(dest_fd, source_fd, pos, left); > + if (ret < 0) { > + say_syserror("sendfile, [%s -> %s]", > + fio_filename(source_fd), > + fio_filename(dest_fd)); > goto error_copy; > + } > + pos += ret; > + left -= ret; > } > + > req->result = 0; > close(source_fd); > close(dest_fd);
next prev parent reply other threads:[~2019-04-16 17:35 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-04-15 21:14 Cyrill Gorcunov 2019-04-16 17:35 ` Vladimir Davydov [this message] 2019-04-16 17:51 ` Cyrill Gorcunov 2019-04-17 8:47 ` Vladimir Davydov
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