Description of problem:

  When compiling on F19, there are many warnings about "warning: ignoring
  return value of 'XXXXXX', declared with attribute warn_unused_result".

  Low priority, but we should probably ensure our code compiles with no
  warnings.


Version-Release number of selected component (if applicable):

  Upstream GlusterFS git head, master branch, as of Tue 17th Sept 2013.


How reproducible:

  Every time.


Steps to Reproduce:
1. Compile GlusterFS using the official upstream Compiling RPMs instructions.
2. The warnings appear for the "make glusterrpms" step.

Actual results:

************************************************************
...
Making all in src
  CC       libglusterfs_la-dict.lo
  CC       libglusterfs_la-xlator.lo
  CC       libglusterfs_la-logging.lo
  CC       libglusterfs_la-hashfn.lo
  CC       libglusterfs_la-defaults.lo
  CC       libglusterfs_la-common-utils.lo
  CC       libglusterfs_la-timer.lo
  CC       libglusterfs_la-inode.lo
  CC       libglusterfs_la-call-stub.lo
  CC       libglusterfs_la-compat.lo
  CC       libglusterfs_la-fd.lo
logging.c: In function 'gf_syslog':
logging.c:290:27: warning: ignoring return value of 'vasprintf', declared with attribute warn_unused_result [-Wunused-result]
                 vasprintf (&msg, format, ap);
                           ^
logging.c: In function '_gf_log_callingfn':
logging.c:637:27: warning: ignoring return value of 'vasprintf', declared with attribute warn_unused_result [-Wunused-result]
                 vasprintf (&str2, fmt, ap);
                           ^
logging.c: In function '_gf_log':
logging.c:774:27: warning: ignoring return value of 'vasprintf', declared with attribute warn_unused_result [-Wunused-result]
                 vasprintf (&str2, fmt, ap);
                           ^
  CC       libglusterfs_la-compat-errno.lo
  CC       libglusterfs_la-event.lo
  CC       libglusterfs_la-mem-pool.lo
  CC       libglusterfs_la-gf-dirent.lo
  CC       libglusterfs_la-syscall.lo
  CC       libglusterfs_la-iobuf.lo
  CC       libglusterfs_la-globals.lo
  CC       libglusterfs_la-statedump.lo
  CC       libglusterfs_la-stack.lo
  CC       libglusterfs_la-checksum.lo
  CC       libglusterfs_la-daemon.lo
  CC       libglusterfs_la-rb.lo
  CC       libglusterfs_la-rbthash.lo
  CC       libglusterfs_la-store.lo
  CC       libglusterfs_la-latency.lo
  CC       libglusterfs_la-graph.lo
store.c: In function 'gf_store_unlock':
store.c:682:15: warning: ignoring return value of 'lockf', declared with attribute warn_unused_result [-Wunused-result]
         lockf (sh->fd, F_ULOCK, 0);
               ^
  CC       libglusterfs_la-clear.lo
  CC       libglusterfs_la-copy.lo
  CC       libglusterfs_la-gen_uuid.lo
  CC       libglusterfs_la-pack.lo
  CC       libglusterfs_la-unparse.lo
  CC       libglusterfs_la-uuid_time.lo
  CC       libglusterfs_la-parse.lo
  CC       libglusterfs_la-compare.lo
  CC       libglusterfs_la-isnull.lo
  CC       libglusterfs_la-unpack.lo
  CC       libglusterfs_la-syncop.lo
  CC       libglusterfs_la-graph-print.lo
  CC       libglusterfs_la-trie.lo
  CC       libglusterfs_la-run.lo
  CC       libglusterfs_la-options.lo
  CC       libglusterfs_la-fd-lk.lo
  CC       libglusterfs_la-circ-buff.lo
  CC       libglusterfs_la-gidcache.lo
  CC       libglusterfs_la-event-history.lo
  CC       libglusterfs_la-ctx.lo
  CC       libglusterfs_la-client_t.lo
  CC       libglusterfs_la-lock-table.lo
  CC       libglusterfs_la-basename_r.lo
  CC       libglusterfs_la-dirname_r.lo
  CC       libglusterfs_la-gf_mkostemp.lo
  CC       libglusterfs_la-event-poll.lo
  CC       libglusterfs_la-event-epoll.lo
  CC       libglusterfs_la-y.tab.lo
  CC       libglusterfs_la-graph.lex.lo
  CCLD     libglusterfs.la
Making all in rpc
Making all in rpc-lib
Making all in src
  CC       auth-unix.lo
  CC       rpcsvc-auth.lo
  CC       rpcsvc.lo
  CC       auth-null.lo
  CC       xdr-rpc.lo
  CC       xdr-rpcclnt.lo
  CC       rpc-transport.lo
  CC       rpc-clnt.lo
  CC       auth-glusterfs.lo
  CC       rpc-drc.lo
  CCLD     libgfrpc.la
Making all in rpc-transport
Making all in socket
Making all in src
  CC       socket.lo
  CC       name.lo
  CCLD     socket.la
Making all in rdma
Making all in src
  CC       rdma.lo
  CC       name.lo
  CCLD     rdma.la
Making all in xdr
Making all in src
  CC       libgfxdr_la-xdr-generic.lo
  CC       libgfxdr_la-rpc-common-xdr.lo
  CC       libgfxdr_la-glusterfs3-xdr.lo
  CC       libgfxdr_la-cli1-xdr.lo
  CC       libgfxdr_la-glusterd1-xdr.lo
  CC       libgfxdr_la-portmap-xdr.lo
  CC       libgfxdr_la-xdr-nfs3.lo
  CC       libgfxdr_la-nlm4-xdr.lo
  CC       libgfxdr_la-msg-nfs3.lo
  CC       libgfxdr_la-nsm-xdr.lo
  CC       libgfxdr_la-nlmcbk-xdr.lo
  CC       libgfxdr_la-acl3-xdr.lo
  CCLD     libgfxdr.la
Making all in api
Making all in src
  CC       libgfapi_la-glfs.lo
  CC       libgfapi_la-glfs-mgmt.lo
  CC       libgfapi_la-glfs-fops.lo
  CC       libgfapi_la-glfs-resolve.lo
  CC       glfs-master.lo
  CCLD     libgfapi.la
  CCLD     api.la
Making all in xlators
Making all in cluster
Making all in stripe
Making all in src
  CC       stripe.lo
  CC       stripe-helpers.lo
  CC       libxlator.lo
  CCLD     stripe.la
Making all in afr
Making all in src
  CC       afr-dir-read.lo
  CC       afr-dir-write.lo
  CC       afr-inode-read.lo
  CC       afr-inode-write.lo
  CC       afr-open.lo
  CC       afr-transaction.lo
  CC       afr-self-heal-data.lo
  CC       afr-self-heal-common.lo
  CC       afr-self-heal-metadata.lo
  CC       afr-self-heal-entry.lo
  CC       afr-self-heal-algorithm.lo
  CC       afr-lk-common.lo
  CC       afr-self-heald.lo
  CC       libxlator.lo
  CC       afr.lo
  CC       pump.lo
  CCLD     afr.la
  CCLD     pump.la
Making all in dht
Making all in src
  CC       dht-layout.lo
  CC       dht-helper.lo
  CC       dht-linkfile.lo
  CC       dht-rebalance.lo
  CC       dht-selfheal.lo
  CC       dht-rename.lo
  CC       dht-hashfn.lo
  CC       dht-diskusage.lo
  CC       dht-common.lo
  CC       dht-inode-write.lo
  CC       dht-inode-read.lo
  CC       dht-shared.lo
  CC       libxlator.lo
  CC       dht.lo
  CC       nufa.lo
  CC       switch.lo
  CCLD     nufa.la
  CCLD     dht.la
  CCLD     switch.la
Making all in storage
Making all in posix
Making all in src
  CC       posix.lo
  CC       posix-helpers.lo
  CC       posix-handle.lo
  CC       posix-aio.lo
  CCLD     posix.la
Making all in bd_map
Making all in src
  CC       bd_map.lo
  CC       bd_map_help.lo
  CCLD     bd_map.la
Making all in protocol
Making all in auth
Making all in addr
Making all in src
  CC       addr.lo
  CCLD     addr.la
Making all in login
Making all in src
  CC       login.lo
  CCLD     login.la
Making all in client
Making all in src
  CC       client.lo
  CC       client-helpers.lo
  CC       client-rpc-fops.lo
  CC       client-handshake.lo
  CC       client-callback.lo
  CC       client-lk.lo
  CCLD     client.la
Making all in server
Making all in src
  CC       server.lo
  CC       server-resolve.lo
  CC       server-helpers.lo
  CC       server-rpc-fops.lo
  CC       server-handshake.lo
  CC       authenticate.lo
  CCLD     server.la
Making all in performance
Making all in write-behind
Making all in src
  CC       write-behind.lo
  CCLD     write-behind.la
Making all in read-ahead
Making all in src
  CC       read-ahead.lo
  CC       page.lo
  CCLD     read-ahead.la
Making all in readdir-ahead
Making all in src
  CC       readdir-ahead.lo
  CCLD     readdir-ahead.la
Making all in io-threads
Making all in src
  CC       io-threads.lo
  CCLD     io-threads.la
Making all in io-cache
Making all in src
  CC       io-cache.lo
  CC       page.lo
  CC       ioc-inode.lo
  CCLD     io-cache.la
Making all in symlink-cache
Making all in src
  CC       symlink-cache.lo
  CCLD     symlink-cache.la
Making all in quick-read
Making all in src
  CC       quick-read.lo
  CCLD     quick-read.la
Making all in md-cache
Making all in src
  CC       md-cache.lo
  CCLD     md-cache.la
Making all in open-behind
Making all in src
  CC       open-behind.lo
  CCLD     open-behind.la
Making all in debug
Making all in trace
Making all in src
  CC       trace.lo
  CCLD     trace.la
Making all in error-gen
Making all in src
  CC       error-gen.lo
  CCLD     error-gen.la
Making all in io-stats
Making all in src
  CC       io-stats.lo
  CCLD     io-stats.la
Making all in features
Making all in locks
Making all in src
  CC       common.lo
  CC       posix.lo
  CC       entrylk.lo
  CC       inodelk.lo
  CC       reservelk.lo
  CC       clear.lo
  CCLD     locks.la
Making all in quota
Making all in src
  CC       quota.lo
  CCLD     quota.la
Making all in read-only
Making all in src
  CC       read-only.lo
  CC       read-only-common.lo
  CC       worm.lo
  CCLD     read-only.la
  CCLD     worm.la
Making all in mac-compat
Making all in src
  CC       mac-compat.lo
  CCLD     mac-compat.la
Making all in quiesce
Making all in src
  CC       quiesce.lo
  CCLD     quiesce.la
Making all in marker
Making all in src
  CC       marker-quota.lo
  CC       marker.lo
  CC       marker-quota-helper.lo
  CC       marker-common.lo
  CCLD     marker.la
Making all in index
Making all in src
  CC       index.lo
  CCLD     index.la
Making all in protect
Making all in src
  CC       prot_dht.lo
  CC       prot_client.lo
  CC       prot_server.lo
  CCLD     prot_dht.la
  CCLD     prot_server.la
  CCLD     prot_client.la
Making all in changelog
Making all in src
  CC       changelog.lo
  CC       changelog-rt.lo
  CC       changelog-helpers.lo
  CC       changelog-encoders.lo
  CC       changelog-notifier.lo
  CCLD     changelog.la
Making all in lib
Making all in src
  CC       libgfchangelog_la-gf-changelog.lo
  CC       libgfchangelog_la-gf-changelog-process.lo
  CC       libgfchangelog_la-gf-changelog-helpers.lo
  CC       libgfchangelog_la-clear.lo
  CC       libgfchangelog_la-copy.lo
  CC       libgfchangelog_la-gen_uuid.lo
  CC       libgfchangelog_la-pack.lo
  CC       libgfchangelog_la-parse.lo
  CC       libgfchangelog_la-unparse.lo
  CC       libgfchangelog_la-uuid_time.lo
  CC       libgfchangelog_la-compare.lo
  CC       libgfchangelog_la-isnull.lo
  CC       libgfchangelog_la-unpack.lo
  CCLD     libgfchangelog.la
Making all in gfid-access
Making all in src
  CC       gfid-access.lo
  CCLD     gfid-access.la
Making all in glupy
Making all in src
  CC       glupy.lo
  CCLD     glupy.la
Making all in qemu-block
Making all in src
  CC       qemu-coroutine.lo
  CC       qemu-coroutine-lock.lo
  CC       qemu-coroutine-sleep.lo
  CC       block.lo
  CC       nop-symbols.lo
  CC       aes.lo
  CC       bitmap.lo
  CC       bitops.lo
  CC       cutils.lo
  CC       error.lo
  CC       hbitmap.lo
  CC       iov.lo
  CC       module.lo
  CC       oslib-posix.lo
  CC       qemu-option.lo
  CC       qemu-error.lo
  CC       qemu-thread-posix.lo
  CC       unicode.lo
  CC       hexdump.lo
  CC       snapshot.lo
  CC       qcow2-cache.lo
  CC       qcow2-cluster.lo
  CC       qcow2-refcount.lo
  CC       qcow2-snapshot.lo
  CC       qcow2.lo
  CC       qed-check.lo
  CC       qed-cluster.lo
  CC       qed-gencb.lo
  CC       qed-l2-cache.lo
  CC       qed-table.lo
  CC       qed.lo
  CC       json-lexer.lo
  CC       json-parser.lo
  CC       json-streamer.lo
  CC       qbool.lo
  CC       qdict.lo
  CC       qerror.lo
  CC       qfloat.lo
  CC       qint.lo
  CC       qjson.lo
  CC       qlist.lo
  CC       qstring.lo
  CC       bdrv-xlator.lo
  CC       coroutine-synctask.lo
  CC       bh-syncop.lo
  CC       monitor-logging.lo
  CC       clock-timer.lo
  CC       qemu-block.lo
  CC       qb-coroutines.lo
  CCLD     qemu-block.la
Making all in encryption
Making all in rot-13
Making all in src
  CC       rot-13.lo
  CCLD     rot-13.la
Making all in mount
Making all in fuse
Making all in src
  CC       fuse-helpers.lo
  CC       fuse-resolve.lo
  CC       fuse-bridge.lo
  CC       misc.lo
  CC       mount.lo
  CC       mount-common.lo
../../../../contrib/fuse-lib/mount-common.c: In function 'fuse_mnt_add_mount':
../../../../contrib/fuse-lib/mount-common.c:108:24: warning: ignoring return value of 'setuid', declared with attribute warn_unused_result [-Wunused-result]
                 setuid (geteuid ());
                        ^
../../../../contrib/fuse-lib/mount-common.c: In function 'mtab_needs_update':
../../../../contrib/fuse-lib/mount-common.c:59:34: warning: ignoring return value of 'setreuid', declared with attribute warn_unused_result [-Wunused-result]
                         setreuid (0, -1);
                                  ^
../../../../contrib/fuse-lib/mount-common.c:64:34: warning: ignoring return value of 'setreuid', declared with attribute warn_unused_result [-Wunused-result]
                         setreuid (ruid, -1);
                                  ^
../../../../contrib/fuse-lib/mount-common.c: In function 'fuse_mnt_umount':
../../../../contrib/fuse-lib/mount-common.c:248:24: warning: ignoring return value of 'setuid', declared with attribute warn_unused_result [-Wunused-result]
                 setuid (geteuid ());
                        ^
../../../../contrib/fuse-lib/mount.c: In function 'gf_fuse_mount':
../../../../contrib/fuse-lib/mount.c:301:25: warning: ignoring return value of 'write', declared with attribute warn_unused_result [-Wunused-result]
                         (void)write (status_fd, &ret, sizeof (ret));
                         ^
  CCLD     fuse.la
Making all in utils
Making all in nfs
Making all in server
Making all in src
  CC       nfs.lo
  CC       nfs-common.lo
  CC       nfs-fops.lo
  CC       nfs-inodes.lo
  CC       nfs-generics.lo
  CC       mount3.lo
  CC       nfs3-fh.lo
  CC       nfs3.lo
  CC       nfs3-helpers.lo
  CC       nlm4.lo
  CC       nlmcbk_svc.lo
  CC       mount3udp_svc.lo
  CC       acl3.lo
  CCLD     server.la
Making all in mgmt
Making all in glusterd
Making all in src
  CC       glusterd_la-glusterd.lo
  CC       glusterd_la-glusterd-handler.lo
  CC       glusterd_la-glusterd-sm.lo
  CC       glusterd_la-glusterd-op-sm.lo
  CC       glusterd_la-glusterd-utils.lo
  CC       glusterd_la-glusterd-rpc-ops.lo
  CC       glusterd_la-glusterd-store.lo
  CC       glusterd_la-glusterd-handshake.lo
  CC       glusterd_la-glusterd-pmap.lo
  CC       glusterd_la-glusterd-volgen.lo
  CC       glusterd_la-glusterd-rebalance.lo
  CC       glusterd_la-glusterd-quota.lo
  CC       glusterd_la-glusterd-geo-rep.lo
  CC       glusterd_la-glusterd-replace-brick.lo
  CC       glusterd_la-glusterd-log-ops.lo
  CC       glusterd_la-glusterd-volume-ops.lo
  CC       glusterd_la-glusterd-brick-ops.lo
  CC       glusterd_la-glusterd-mountbroker.lo
  CC       glusterd_la-glusterd-syncop.lo
  CC       glusterd_la-glusterd-hooks.lo
  CC       glusterd_la-glusterd-volume-set.lo
  CCLD     glusterd.la
Making all in system
Making all in posix-acl
Making all in src
  CC       posix-acl.lo
  CC       posix-acl-xattr.lo
  CCLD     posix-acl.la
Making all in playground
Making all in template
Making all in src
  CC       template.lo
  CCLD     template.la
Making all in glusterfsd
Making all in src
  CC       glusterfsd.o
  CC       glusterfsd-mgmt.o
glusterfsd.c: In function 'emancipate':
glusterfsd.c:1145:23: warning: ignoring return value of 'write', declared with attribute warn_unused_result [-Wunused-result]
                 write (ctx->daemon_pipe[1], (void *) &ret, sizeof (ret));
                       ^
glusterfsd.c: In function 'daemonize':
glusterfsd.c:1823:22: warning: ignoring return value of 'read', declared with attribute warn_unused_result [-Wunused-result]
                 read (ctx->daemon_pipe[0], (void *)&err, sizeof (err));
                      ^
  CCLD     glusterfsd
Making all in contrib/fuse-util
  CC       fusermount.o
  CC       mount_util.o
  CC       mount-common.o
../../contrib/fuse-lib/mount-common.c: In function 'fuse_mnt_add_mount':
../../contrib/fuse-lib/mount-common.c:108:24: warning: ignoring return value of 'setuid', declared with attribute warn_unused_result [-Wunused-result]
                 setuid (geteuid ());
                        ^
../../contrib/fuse-lib/mount-common.c: In function 'mtab_needs_update':
../../contrib/fuse-lib/mount-common.c:59:34: warning: ignoring return value of 'setreuid', declared with attribute warn_unused_result [-Wunused-result]
                         setreuid (0, -1);
                                  ^
../../contrib/fuse-lib/mount-common.c:64:34: warning: ignoring return value of 'setreuid', declared with attribute warn_unused_result [-Wunused-result]
                         setreuid (ruid, -1);
                                  ^
../../contrib/fuse-lib/mount-common.c: In function 'fuse_mnt_umount':
../../contrib/fuse-lib/mount-common.c:248:24: warning: ignoring return value of 'setuid', declared with attribute warn_unused_result [-Wunused-result]
                 setuid (geteuid ());
                        ^
fusermount.c: In function 'restore_privs':
fusermount.c:80:11: warning: ignoring return value of 'setfsuid', declared with attribute warn_unused_result [-Wunused-result]
   setfsuid(oldfsuid);
           ^
fusermount.c:81:11: warning: ignoring return value of 'setfsgid', declared with attribute warn_unused_result [-Wunused-result]
   setfsgid(oldfsgid);
           ^
  CCLD     fusermount-glusterfs
Making all in doc
Making all in extras
Making all in init.d
Making all in systemd
Making all in benchmarking
Making all in hook-scripts
Making all in ocf
Making all in LinuxRPM
To build RPMS run 'make glusterrpms'
Making all in geo-rep
Making all in cli
Making all in src
...
************************************************************


Expected results:

No warnings to appear for the compile process.