Re: [Xen-devel] Errors of doing "make install-tools" with xen-4.2-unstable?

[Keir Fraser <keir@xxxxxxx>]

On 11/05/2012 17:24, "Ian Campbell" <Ian.Campbell@xxxxxxxxxx> wrote:

> On Fri, 2012-05-11 at 17:10 +0100, Bei Guan wrote:
> 
> 
>> No, it doesn't work for me. There is the same error.
> 
> Hrm. Since you can reproduce would you mind experimenting a bit to
> figure out the correct fix for this?
> 
> Perhaps adding -Wno-unused-result to C flags helps (google suggests it
> may not)?
> 
> Or maybe just assigning to a dummy variable.

Bei, Please try the attached patch.

 -- Keir

> Ian.
> 
>> My environment and gcc version are like this:
>> 
>> root@gavin-desktop:~# uname -a
>> Linux gavin-desktop 2.6.32-5-xen-amd64 #1 SMP Thu May 19 01:16:47 UTC
>> 2011 x86_64 GNU/Linux
>> 
>> root@gavin-desktop:~# gcc -v
>> Using built-in specs.
>> Target: x86_64-linux-gnu
>> Configured with: ../src/configure -v --with-pkgversion='Ubuntu
>> 4.4.3-4ubuntu5'
>> --with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs
>> --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr
>> --enable-shared --enable-multiarch --enable-linker-build-id
>> --with-system-zlib --libexecdir=/usr/lib --without-included-gettext
>> --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.4
>> --program-suffix=-4.4 --enable-nls --enable-clocale=gnu
>> --enable-libstdcxx-debug --enable-plugin --enable-objc-gc
>> --disable-werror --with-arch-32=i486 --with-tune=generic
>> --enable-checking=release --build=x86_64-linux-gnu
>> --host=x86_64-linux-gnu --target=x86_64-linux-gnu
>> Thread model: posix
>> gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5)
>> 
>> 
>> 
>> 
>> Thanks,
>> Bei Guan
>> 
>> 
>> 
>>  
>>         
>>         8<------------------------------------------------------
>>         
>>         # HG changeset patch
>>         # User Ian Campbell <ian.campbell@xxxxxxxxxx>
>>         # Date 1336751175 -3600
>>         # Node ID 15ed8f45c4e57a1e206af020e0ff17b792108e99
>>         # Parent  adc74e492edfee6cf44e433e3e93743a3cf71999
>>         blktap: avoid attribute warn_unused_result build failures.
>>         
>>         I'm not proud of this, but since none of these callers of
>>         read/write have any
>>         other error handling and return void themselves (for several
>>         links up the call
>>         chain AFAICT) and because I don't really want to get into a
>>         massive reworking
>>         of blktap2 I suppose it is at least pragmatic
>>         
>>         Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
>>         
>>         diff -r adc74e492edf -r 15ed8f45c4e5
>>         tools/blktap2/drivers/tapdisk-log.c
>>         --- a/tools/blktap2/drivers/tapdisk-log.c       Fri May 11
>>         16:19:16 2012 +0100
>>         +++ b/tools/blktap2/drivers/tapdisk-log.c       Fri May 11
>>         16:46:15 2012 +0100
>>         @@ -247,7 +247,7 @@ tlog_flush(void)
>>                wsize = ((size + 511) & (~511));
>>         
>>                memset(tapdisk_log.buf + size, '\n', wsize - size);
>>         -       write(fd, tapdisk_log.buf, wsize);
>>         +       (void)write(fd, tapdisk_log.buf, wsize);
>>         
>>                tapdisk_log.p = tapdisk_log.buf;
>>         
>>         diff -r adc74e492edf -r 15ed8f45c4e5
>>         tools/blktap2/drivers/tapdisk-queue.c
>>         --- a/tools/blktap2/drivers/tapdisk-queue.c     Fri May 11
>>         16:19:16 2012 +0100
>>         +++ b/tools/blktap2/drivers/tapdisk-queue.c     Fri May 11
>>         16:46:15 2012 +0100
>>         @@ -435,7 +435,7 @@ tapdisk_lio_ack_event(struct tqueue *que
>>                uint64_t val;
>>         
>>                if (lio->flags & LIO_FLAG_EVENTFD)
>>         -               read(lio->event_fd, &val, sizeof(val));
>>         +               (void)read(lio->event_fd, &val, sizeof(val));
>>          }
>>         
>>          static void
>>         diff -r adc74e492edf -r 15ed8f45c4e5
>>         tools/blktap2/drivers/tapdisk-stream.c
>>         --- a/tools/blktap2/drivers/tapdisk-stream.c    Fri May 11
>>         16:19:16 2012 +0100
>>         +++ b/tools/blktap2/drivers/tapdisk-stream.c    Fri May 11
>>         16:46:15 2012 +0100
>>         @@ -145,7 +145,7 @@ tapdisk_stream_poll_clear(struct tapdisk
>>          {
>>                int dummy;
>>         
>>         -       read(p->pipe[POLL_READ], &dummy, sizeof(dummy));
>>         +       (void)read(p->pipe[POLL_READ], &dummy, sizeof(dummy));
>>                p->set = 0;
>>          }
>>         
>>         @@ -155,7 +155,7 @@ tapdisk_stream_poll_set(struct tapdisk_s
>>                int dummy = 0;
>>         
>>                if (!p->set) {
>>         -               write(p->pipe[POLL_WRITE], &dummy,
>>         sizeof(dummy));
>>         +               (void)write(p->pipe[POLL_WRITE], &dummy,
>>         sizeof(dummy));
>>                        p->set = 1;
>>                }
>>          }
>>         @@ -203,7 +203,7 @@ tapdisk_stream_print_request(struct tapd
>>          {
>>                unsigned long idx = (unsigned
>>         long)tapdisk_stream_request_idx(s, sreq);
>>                char *buf = (char *)MMAP_VADDR(s->vbd->ring.vstart,
>>         idx, 0);
>>         -       write(s->out_fd, buf, sreq->secs << SECTOR_SHIFT);
>>         +       (void)write(s->out_fd, buf, sreq->secs <<
>>         SECTOR_SHIFT);
>>          }
>>         
>>          static void
>>         diff -r adc74e492edf -r 15ed8f45c4e5
>>         tools/blktap2/drivers/tapdisk2.c
>>         --- a/tools/blktap2/drivers/tapdisk2.c  Fri May 11 16:19:16
>>         2012 +0100
>>         +++ b/tools/blktap2/drivers/tapdisk2.c  Fri May 11 16:46:15
>>         2012 +0100
>>         @@ -79,7 +79,12 @@ main(int argc, char *argv[])
>>                if (optind != argc)
>>                        usage(argv[0], EINVAL);
>>         
>>         -       chdir("/");
>>         +       if (chdir("/")) {
>>         +               DPRINTF("failed to chdir(/): %d\n", errno);
>>         +               err = 1;
>>         +               goto out;
>>         +       }
>>         +
>>                tapdisk_start_logging("tapdisk2");
>>         
>>                err = tapdisk_server_init();
>>         
>>         
>> 
>> 
>> 
>> -- 
>> Best Regards,
>> Bei Guan
>> 
> 
>

Attachment: 00-tapdisk-check-io-result
Description: Binary data

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel