[dm-devel] [PATCH v3 00/72] multipath-tools: cleanup and warning enablement

Martin Wilck Martin.Wilck at suse.com
Thu Nov 7 09:27:34 UTC 2019


From: Martin Wilck <mwilck at suse.com>

Hi Christophe, hi Ben, hi Bart,

(I found a glitch in the v2 submission of this series. Details below).

here is a series with cleanup patches and minor fixes for multipath-tools.
Sorry about the number of patches, I hope this way the series will be easier
to review. There are lots of obvious, short hunks. In terms of LoC, most
of the changes are in a new unit test, in the NVMe code update, and in
a (necessary) indentation change in the VPD code.

Patch 01-14 are part of a recent effort to go over the multipath-tools
code, re-review, and modernize the code a bit. Part of that is adding "const"
qualifiers to function arguments, as I did before. I happened to start with
"alias.c", for alphabetic reasons. Other parts of the code will hopefully
follow.

15-20 are misc fixes for stuff I came across while working on the
"-Wclobbered" flag (see below).

The rest of the series is an attempt to get rid of the disablement of
warnings that we had so far in multipath-tools. I believe we agree that
warning-free code is a good thing and that disabling warnings should be
avoided if possible. My goal was to be able to set "-Werror" and compile
successfully with all currently relevant compilers.

Patch 21-42 fix issues with -Wunused-parameter and finally enable that
warning. -Wno-unused-parameter is only kept in place for
libmultipath/dict.c and multipathd/cli-handlers.c, which basically consist
only of implementations of certain prototypes where many functions don't
use every argument, and hundreds of "unused" attributes would pollute the
code too much. Patch 53-58 fix issues with "-Wsign-compare". This was
actually a good excercise, because I was forced to think twice which
signedness was correct for certain variables and expressions. Patch 59-64
fix some warnings that are issued by clang with our current warning settings
(in particular, -Wformat-literal).

Patch 65 is an update of our nvme code from nvme-cli 1.9. Patch 66-71
contain some make file fixes and cleanups, and adaptations for older
compilers. Finally, Patch 71 enables -Werror, and patch 72 tests for
"-Wno-clobbered", which clang doesn't support.

I can proudly say that multipath-tools now compiles without warnings or
errors with -Werror and with a large set of compilers. I tested gcc 4.8,
7, 8, 9 and clang 3.9, 6, 7, and 8.

The only "-Wno" option that now remains is "-Wclobbered". I have put
considerable work into trying to eliminate that as well. The result
can be examined in the "Wclobbered" branch of my github fork:
https://github.com/mwilck/multipath-tools/commits/Wclobbered
(yes, that's another 37 patches on top of this already long series).

I have pondered this back and forth whether to submit that part of the
series, too. All the -Wclobbered warnings are caused by pthread_cleanup_push()
calls, of which our code has a lot, and which glibc implements using a
sigsetjmp() call. These warnings are arguably a false positives, and
a bug of either gcc, glibc, or both
(see e.g. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61118). 

Eliminating these warnings is possible, but it requires a lot of changes
in the code. Some of them are actually beneficial for readability, but
others are rather not. Some are outright mysterious (e.g.
https://github.com/mwilck/multipath-tools/commit/bb53d666777f072e60372979eed51752db03cec4),
and finding the workarounds was trial-and error work. Also, there are
variations between gcc versions.

The bottom line is, while I feel sorry about the vain effort 
I put into this, my personal opinion is that silencing just this single
warning isn't worth that big amount of changes.

Reviews and opinions welcome.

Regards
Martin

Changes v1 -> v2:
  45/72: The way I handled snprintf() was wrong. Fix it, and use
         safe_sn?printf() to hide cast ugliness (Bart van Assche)
Changes v2 -> v3:
  45/72: safe_snprintf(): Replaced wrong references to macro argument
  	 "size" with variable "__size".

All other patches remain unchanged, not resending them.

Martin Wilck (72):
  multipath tests: move condlog test wrappers to separate file
  multipath tests: add tests for alias handling
  libmultipath: alias.c: constify function arguments
  libmultipath: alias.c: use strlcpy(), and 2 minor fixes
  libmultipath: format_devname: avoid buffer overflow
  libmultipath: scan_devname: fix int overflow detection
  libmultipath: lookup_binding(): don't rely on int overflow
  libmultipath: rlookup_binding(): removed unused parameter
  libmultipath: allocate_binding(): error out for id=0
  libmultipath: allocate_binding(): detect line overflow
  multipath tests: alias: add tests for allocate_binding()
  multipath tests: alias: add format/scan test
  libmultipath: alias.c: prepare for cancel-safe allocation
  multipath tests: use -lpthread for alias test
  libmultipath: path_discovery: handle libudev errors
  libmultipath: make path_discovery() pthread_cancel()-safe
  libmultipath: uevent_listen(): fix poll() retval check
  libmultipath: replace_wwids(): fix possible fd leak
  libmultipath: remove_wwids(): fix possible leaks
  libmultipath: _init_foreign(): fix possible memory leak
  libmultipath: process_config_dir(): remove unused argument
  libmultipath: mark unused arguments in partmap functions
  libmultipath: scsi_ioctl_pathinfo(): remove unused argument
  multipath-tools: mark unused params in signal and cleanup handlers
  libmultipath: get_ana_info(): remove unused parameter
  libmultipath: mark unused params in getprio() methods
  libmultipath: hp_sw: remove usused argument in do_inq()
  libmultipath: checkers: mark unused arguments in methods
  multipathd: stop_waiter_thread(): removed unused parameter
  multipath tools: mark unused arguments in thread routines
  kpartx: gpt: remove unused arg in read_lastoddsector()
  kpartx: mark unused arguments in ptreader methods
  libmultipath: mark missing arguments in functions matching prototypes
  libmultipath: get_pgpolicy_name(): use "len" parameter
  libmultipath: snprint_multipath_map_json(): remove unused argument
  multipath: delegate_to_multipathd: mark unused arguments
  libmultipath: use -Wno-unused-parameter for dict.c
  multipathd: use -Wno-unused-parameter for cli_handlers.c
  libmpathpersist: remove unused "noisy" argument in various functions
  libmpathpersist: fix copy-paste error in mpath_format_readresv()
  multipath-tools tests: add -Wno-unused-parameter
  multipath-tools: Makefile.inc: remove -Wno-unused-parameter
  libmultipath: dev_loss_tmo is unsigned
  libmultipath: trivial changes for -Wsign-compare
  libmultipath: fix -Wsign-compare warnings with snprintf()
  libmultipath: parse_vpd_pg83(): sanitize indentation
  libmultipath: parse_vpd_pg83(): fix -Wsign-compare warnings
  libmultipath: print: use unsigned int for "width" field
  libmultipath: vector_for_each_slot: fix -Wsign-compare warnings
  libmultipath: set_int(): add error check and set_uint()
  libmultipath: make "checkint" unsigned
  libmultipath: use unsigned blksize in directio context
  libmultipath, kpartx: byteorder: always use unsigned types
  libmpathcmd: fix -Wsign-compare warnings
  libmpathpersist: fix -Wsign-compare warnings
  kpartx: use unsigned arguments in dm_devn() and dm_prereq()
  kpartx: use unsigned int for "ns" argument of ptreader
  multipath-tools: Makefile.inc: enable -Wsign-compare
  libdmmp: fix clang -Wformat-nonliteral warnings
  libmultipath: fix clang -Wformat-literal warnings
  multipath tests: blacklist: remove always-true condition
  multipath tests: hwtable: fix strncat() invocation
  multipath tests: fix -Wformat-literal warning
  multipath tests: util: fix clang strlcpy warnings
  libmultipath: nvme: update to nvme-cli v1.9
  multipath-tools: Makefile.inc: fix TEST_CC_OPTION
  multipath-tools: Makefile.inc: use -Wp,... for compiling only
  multipath-tools: Makefile: use proper directory recursion
  multipath tests: Makefile: fix "clean" target
  multipath tests: Makefile: avoid gcc 4.8 missing initializers failure
  multipath-tools: Makefile.inc: enable -Werror
  multipath-tools: Makefile.inc: test for -Wno-clobbered support

 Makefile                                 |  38 +-
 Makefile.inc                             |  15 +-
 kpartx/bsd.c                             |   4 +-
 kpartx/dasd.c                            |   3 +-
 kpartx/devmapper.c                       |  13 +-
 kpartx/devmapper.h                       |   7 +-
 kpartx/dos.c                             |   4 +-
 kpartx/gpt.c                             |  15 +-
 kpartx/gpt.h                             |   2 +-
 kpartx/kpartx.h                          |  20 +-
 kpartx/mac.c                             |   5 +-
 kpartx/ps3.c                             |   5 +-
 kpartx/solaris.c                         |   4 +-
 kpartx/sun.c                             |   4 +-
 kpartx/unixware.c                        |   4 +-
 libdmmp/libdmmp_private.h                |   8 +-
 libmpathcmd/mpath_cmd.c                  |   5 +-
 libmpathpersist/mpath_persist.c          |   3 +-
 libmpathpersist/mpath_pr_ioctl.c         |  40 +-
 libmultipath/Makefile                    |   5 +
 libmultipath/alias.c                     | 134 ++--
 libmultipath/alias.h                     |  12 +-
 libmultipath/byteorder.h                 |  12 +-
 libmultipath/checkers/cciss_tur.c        |   4 +-
 libmultipath/checkers/directio.c         |   2 +-
 libmultipath/checkers/hp_sw.c            |   8 +-
 libmultipath/checkers/rdac.c             |   2 +-
 libmultipath/checkers/readsector0.c      |   4 +-
 libmultipath/config.c                    |   4 +-
 libmultipath/config.h                    |   4 +-
 libmultipath/defaults.h                  |   4 +-
 libmultipath/devmapper.c                 |  10 +-
 libmultipath/dict.c                      |  52 +-
 libmultipath/discovery.c                 | 284 +++++----
 libmultipath/discovery.h                 |   2 +-
 libmultipath/dm-generic.c                |   6 +-
 libmultipath/file.c                      |   5 +-
 libmultipath/foreign.c                   |  20 +-
 libmultipath/foreign/nvme.c              |  26 +-
 libmultipath/generic.c                   |   2 +-
 libmultipath/io_err_stat.c               |  10 +-
 libmultipath/log.h                       |   3 +-
 libmultipath/log_pthread.c               |   2 +-
 libmultipath/log_pthread.h               |   3 +-
 libmultipath/nvme/linux/nvme.h           | 136 ++++-
 libmultipath/nvme/nvme-ioctl.c           | 229 ++++---
 libmultipath/nvme/nvme-ioctl.h           |  31 +-
 libmultipath/nvme/nvme.h                 | 121 +++-
 libmultipath/parser.c                    |   2 +-
 libmultipath/pgpolicies.c                |   2 +-
 libmultipath/print.c                     |  14 +-
 libmultipath/print.h                     |   8 +-
 libmultipath/prioritizers/alua_rtpg.c    |   2 +-
 libmultipath/prioritizers/ana.c          |  14 +-
 libmultipath/prioritizers/const.c        |   4 +-
 libmultipath/prioritizers/datacore.c     |   3 +-
 libmultipath/prioritizers/emc.c          |   3 +-
 libmultipath/prioritizers/hds.c          |   3 +-
 libmultipath/prioritizers/hp_sw.c        |   3 +-
 libmultipath/prioritizers/iet.c          |   3 +-
 libmultipath/prioritizers/ontap.c        |   3 +-
 libmultipath/prioritizers/random.c       |   4 +-
 libmultipath/prioritizers/rdac.c         |   3 +-
 libmultipath/prioritizers/sysfs.c        |   3 +-
 libmultipath/prioritizers/weightedpath.c |   3 +-
 libmultipath/structs.c                   |   4 +-
 libmultipath/structs.h                   |   3 +-
 libmultipath/structs_vec.c               |   2 +-
 libmultipath/sysfs.c                     |  13 +-
 libmultipath/time-util.c                 |   6 +-
 libmultipath/uevent.c                    |   5 +-
 libmultipath/util.c                      |   7 +-
 libmultipath/util.h                      |  15 +-
 libmultipath/uxsock.c                    |   3 +-
 libmultipath/vector.h                    |   4 +-
 libmultipath/wwids.c                     |  40 +-
 mpathpersist/main.c                      |   2 +-
 multipath/main.c                         |  11 +-
 multipathd/Makefile                      |   3 +
 multipathd/cli_handlers.c                |   2 +-
 multipathd/dmevents.c                    |   4 +-
 multipathd/main.c                        |  36 +-
 multipathd/pidfile.c                     |   2 +-
 multipathd/waiter.c                      |   2 +-
 multipathd/waiter.h                      |   2 +-
 tests/Makefile                           |  19 +-
 tests/alias.c                            | 744 +++++++++++++++++++++++
 tests/blacklist.c                        |  22 +-
 tests/hwtable.c                          |   2 +-
 tests/test-log.c                         |  27 +
 tests/test-log.h                         |   7 +
 tests/util.c                             |  16 +-
 92 files changed, 1818 insertions(+), 598 deletions(-)
 create mode 100644 tests/alias.c
 create mode 100644 tests/test-log.c
 create mode 100644 tests/test-log.h

-- 
2.23.0





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