Commit Graph

32 Commits

Author SHA1 Message Date
Richard Yao 7584fbe846
Cleanup: Switch to strlcpy from strncpy
Coverity found a bug in `zfs_secpolicy_create_clone()` where it is
possible for us to pass an unterminated string when `zfs_get_parent()`
returns an error. Upon inspection, it is clear that using `strlcpy()`
would have avoided this issue.

Looking at the codebase, there are a number of other uses of `strncpy()`
that are unsafe and even when it is used safely, switching to
`strlcpy()` would make the code more readable. Therefore, we switch all
instances where we use `strncpy()` to use `strlcpy()`.

Unfortunately, we do not portably have access to `strlcpy()` in
tests/zfs-tests/cmd/zfs_diff-socket.c because it does not link to
libspl. Modifying the appropriate Makefile.am to try to link to it
resulted in an error from the naming choice used in the file. Trying to
disable the check on the file did not work on FreeBSD because Clang
ignores `#undef` when a definition is provided by `-Dstrncpy(...)=...`.
We workaround that by explictly including the C file from libspl into
the test. This makes things build correctly everywhere.

We add a deprecation warning to `config/Rules.am` and suppress it on the
remaining `strncpy()` usage. `strlcpy()` is not portably avaliable in
tests/zfs-tests/cmd/zfs_diff-socket.c, so we use `snprintf()` there as a
substitute.

This patch does not tackle the related problem of `strcpy()`, which is
even less safe. Thankfully, a quick inspection found that it is used far
more correctly than strncpy() was used. A quick inspection did not find
any problems with `strcpy()` usage outside of zhack, but it should be
said that I only checked around 90% of them.

Lastly, some of the fields in kstat_t varied in size by 1 depending on
whether they were in userspace or in the kernel. The origin of this
discrepancy appears to be 04a479f706 where
it was made for no apparent reason. It conflicts with the comment on
KSTAT_STRLEN, so we shrink the kernel field sizes to match the userspace
field sizes.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13876
2022-09-27 16:35:29 -07:00
наб a926aab902 Enable -Wwrite-strings
Also, fix leak from ztest_global_vars_to_zdb_args()

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13348
2022-06-29 14:08:54 -07:00
наб c8970f52ed autoconf: use include directives instead of recursing down lib
As a bonus, this also adds zfs-mount-generator (previously undescended
down) and libzstd (not included) to CppCheck

As a bonus bonus, abigail rules work out-of-tree, too

Against current trunk:
  $ diff -U0 ./destdir.listing ~/store/code/zfs/destdir.listing
  -destdir/usr/local/include/libspl/sscanf.h

  $ diff --color -U0 ./zfs-2.1.99.tar.gz.listing ../oot/zfs-2.1.99.tar.gz.listing | grep -v @@ | grep -v /Makefile
  -zfs-2.1.99/config/Abigail.am
  -zfs-2.1.99/lib/libspl/include/util/
  -zfs-2.1.99/lib/libspl/include/util/sscanf.h

  $ diff --color -U0 ./zfs-2.1.99.tar.gz.listing ../oot/zfs-2.1.99.tar.gz.listing | grep -v @@ | grep /Makefile
  -zfs-2.1.99/lib/libavl/Makefile.in
  -zfs-2.1.99/lib/libefi/Makefile.in
  -zfs-2.1.99/lib/libicp/Makefile.in
  -zfs-2.1.99/lib/libnvpair/Makefile.in
  -zfs-2.1.99/lib/libshare/Makefile.in
  -zfs-2.1.99/lib/libspl/include/Makefile.in
  -zfs-2.1.99/lib/libspl/include/os/freebsd/Makefile.am
  -zfs-2.1.99/lib/libspl/include/os/freebsd/Makefile.in
  -zfs-2.1.99/lib/libspl/include/os/freebsd/sys/Makefile.am
  -zfs-2.1.99/lib/libspl/include/os/freebsd/sys/Makefile.in
  -zfs-2.1.99/lib/libspl/include/os/linux/Makefile.am
  -zfs-2.1.99/lib/libspl/include/os/linux/Makefile.in
  -zfs-2.1.99/lib/libspl/include/os/linux/sys/Makefile.am
  -zfs-2.1.99/lib/libspl/include/os/linux/sys/Makefile.in
  -zfs-2.1.99/lib/libspl/include/os/Makefile.am
  -zfs-2.1.99/lib/libspl/include/os/Makefile.in
  -zfs-2.1.99/lib/libspl/include/rpc/Makefile.am
  -zfs-2.1.99/lib/libspl/include/rpc/Makefile.in
  -zfs-2.1.99/lib/libspl/include/sys/dktp/Makefile.am
  -zfs-2.1.99/lib/libspl/include/sys/dktp/Makefile.in
  -zfs-2.1.99/lib/libspl/include/sys/Makefile.am
  -zfs-2.1.99/lib/libspl/include/sys/Makefile.in
  -zfs-2.1.99/lib/libspl/include/util/Makefile.am
  -zfs-2.1.99/lib/libspl/include/util/Makefile.in
  -zfs-2.1.99/lib/libspl/Makefile.in
  -zfs-2.1.99/lib/libtpool/Makefile.in
  -zfs-2.1.99/lib/libunicode/Makefile.in
  -zfs-2.1.99/lib/libuutil/Makefile.in
  -zfs-2.1.99/lib/libzfsbootenv/Makefile.in
  -zfs-2.1.99/lib/libzfs_core/Makefile.in
  -zfs-2.1.99/lib/libzfs/Makefile.in
  -zfs-2.1.99/lib/libzpool/Makefile.in
  -zfs-2.1.99/lib/libzstd/Makefile.in
  -zfs-2.1.99/lib/libzutil/Makefile.in
  -zfs-2.1.99/lib/Makefile.in

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13316
2022-05-10 10:18:11 -07:00
наб 3c69b539fe Forbid asctime{,_r}(), gmtime(), localtime()
ctime() is only used in binary main threads, which is fine

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13284
2022-04-05 09:45:46 -07:00
наб d465fc5844 Forbid b{copy,zero,cmp}(). Don't include <strings.h> for <string.h>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12996
2022-03-15 15:13:48 -07:00
наб a2995e7641 config: add -Wextra (sans sign-compare and missing-field-initializers)
Reviewed-by: Alejandro Colomar <alx.manpages@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13110
2022-02-18 09:35:02 -08:00
Damian Szuberski 63652e1546
Add `--enable-asan` and `--enable-ubsan` switches
`configure` now accepts `--enable-asan` and `--enable-ubsan` switches
which results in passing `-fsanitize=address`
and `-fsanitize=undefined`, respectively, to the compiler. Those
flags are enabled in GitHub workflows for ZTS and zloop. Errors
reported by both instrumentations are corrected, except for:

- Memory leak reporting is (temporarily) suppressed. The cost of
  fixing them is relatively high compared to the gains.

- Checksum computing functions in `module/zcommon/zfs_fletcher*`
  have UBSan errors suppressed. It is completely impractical
  to enforce 64-byte payload alignment there due to performance
  impact.

- There's no ASan heap poisoning in `module/zstd/lib/zstd.c`. A custom
  memory allocator is used there rendering that measure
  unfeasible.

- Memory leaks detection has to be suppressed for `cmd/zvol_id`.
  `zvol_id` is run by udev with the help of `ptrace(2)`. Tracing is
  incompatible with memory leaks detection.

Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes #12928
2022-02-03 14:35:38 -08:00
Brian Behlendorf 6954c22f35
Use fallthrough macro
As of the Linux 5.9 kernel a fallthrough macro has been added which
should be used to anotate all intentional fallthrough paths.  Once
all of the kernel code paths have been updated to use fallthrough
the -Wimplicit-fallthrough option will because the default.  To
avoid warnings in the OpenZFS code base when this happens apply
the fallthrough macro.

Additional reading: https://lwn.net/Articles/794944/

Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #12441
2021-09-14 10:17:54 -06:00
Kevin Bowling ca14e08cbf
Detect HAVE_LARGE_STACKS at compile time
Move HAVE_LARGE_STACKS definitions to header and set when appropriate.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Kevin Bowling <kbowling@FreeBSD.org>
Closes #12350
2021-07-16 14:28:55 -06:00
наб feb04e6680 Forbid basename(3) and dirname(3)
There are at least two interpretations of basename(3),
in addition to both functions being allowed to /both/ return a static
buffer (unsuitable in multi-threaded environments) /and/ raze the input
(which encourages overallocations, at best)

Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12105
2021-06-11 09:10:21 -07:00
наб a1ca39655b Forbid strtok(3)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12094
2021-05-26 14:51:30 -07:00
Colm 658fb8020f
Add "compatibility" property for zpool feature sets
Property to allow sets of features to be specified; for compatibility
with specific versions / releases / external systems. Influences
the behavior of 'zpool upgrade' and 'zpool create'. Initial man
page changes and test cases included.

Brief synopsis:

zpool create -o compatibility=off|legacy|file[,file...] pool vdev...

compatibility = off : disable compatibility mode (enable all features)
compatibility = legacy : request that no features be enabled
compatibility = file[,file...] : read features from specified files.
Only features present in *all* files will be enabled on the
resulting pool. Filenames may be absolute, or relative to
/etc/zfs/compatibility.d or /usr/share/zfs/compatibility.d (/etc
checked first).

Only affects zpool create, zpool upgrade and zpool status.

ABI changes in libzfs:

* New function "zpool_load_compat" to load and parse compat sets.
* Add "zpool_compat_status_t" typedef for compatibility parse status.
* Add ZPOOL_PROP_COMPATIBILITY to the pool properties enum
* Add ZPOOL_STATUS_COMPATIBILITY_ERR to the pool status enum

An initial set of base compatibility sets are included in
cmd/zpool/compatibility.d, and the Makefile for cmd/zpool is
modified to install these in $pkgdatadir/compatibility.d and to
create symbolic links to a reasonable set of aliases.

Reviewed-by: ericloewe
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Colm Buckley <colm@tuatha.org>
Closes #11468
2021-02-17 21:30:45 -08:00
Brian Behlendorf 0e6c493fec cppcheck: integrete cppcheck
In order for cppcheck to perform a proper analysis it needs to be
aware of how the sources are compiled (source files, include
paths/files, extra defines, etc).  All the needed information is
available from the Makefiles and can be leveraged with a generic
cppcheck Makefile target.  So let's add one.

Additional minor changes:

* Removing the cppcheck-suppressions.txt file.  With cppcheck 2.3
  and these changes it appears to no longer be needed.  Some inline
  suppressions were also removed since they appear not to be
  needed.  We can add them back if it turns out they're needed
  for older versions of cppcheck.

* Added the ax_count_cpus m4 macro to detect at configure time how
  many processors are available in order to run multiple cppcheck
  jobs.  This value is also now used as a replacement for nproc
  when executing the kernel interface checks.

* "PHONY =" line moved in to the Rules.am file which is included
  at the top of all Makefile.am's.  This is just convenient becase
  it allows us to use the += syntax to add phony targets.

* One upside of this integration worth mentioning is it now allows
  `make cppcheck` to be run in any directory to check that subtree.

* For the moment, cppcheck is not run against the FreeBSD specific
  kernel sources.  The cppcheck-FreeBSD target will need to be
  implemented and testing on FreeBSD to support this.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #11508
2021-01-26 16:12:26 -08:00
Matthew Macy 5678d3f593
Prefix zfs internal endian checks with _ZFS
FreeBSD defines _BIG_ENDIAN BIG_ENDIAN _LITTLE_ENDIAN
LITTLE_ENDIAN on every architecture. Trying to do
cross builds whilst hiding this from ZFS has proven
extremely cumbersome.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10621
2020-07-28 13:02:49 -07:00
Arvind Sankar 109d2c9310 Move zfs_gitrev.h to build directory
Currently an out-of-tree build does not work with read-only source
directory because zfs_gitrev.h can't be created. Move this file to the
build directory, which is more appropriate for a generated file, and
drop the dist-hook for zfs_gitrev.h. There is no need to distribute this
file since it will be regenerated as part of the compilation in any
case.

scripts/make_gitrev.sh tries to avoid updating zfs_gitrev.h if there has
been no change, however this doesn't cover the case when the source
directory is not in git: in that case zfs_gitrev.h gets overwritten even
though it's always "unknown". Simplify the logic to always write out a
new version of zfs_gitrev.h, compare against the old and overwrite only
if different. This is now simple enough to just include in the
Makefile, so drop the script.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10493
2020-06-24 18:19:28 -07:00
Arvind Sankar ae7b167a98 Enable -Wmissing-prototypes/-Wstrict-prototypes
Switch on warning flags to detect mismatch between declaration and
definition.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10470
2020-06-18 12:21:53 -07:00
Matthew Macy 9f0a21e641
Add FreeBSD support to OpenZFS
Add the FreeBSD platform code to the OpenZFS repository.  As of this
commit the source can be compiled and tested on FreeBSD 11 and 12.
Subsequent commits are now required to compile on FreeBSD and Linux.
Additionally, they must pass the ZFS Test Suite on FreeBSD which is
being run by the CI.  As of this commit 1230 tests pass on FreeBSD
and there are no unexpected failures.

Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #898 
Closes #8987
2020-04-14 11:36:28 -07:00
Matthew Macy d31277abb1 OpenZFS restructuring - libspl
Factor Linux specific pieces out of libspl.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9336
2019-10-02 10:39:48 -07:00
Richard Elling d5d2ef2b26 compile with -fno-omit-frame-pointer
By default, depending on the version, gcc can reuse the frame pointer register.
This is a micro-optimization that might help on some very old x86 processors.
However, it also makes dynamic tracing less useful because the stacks cannot
be easily observed.

This rule change instructs gcc to use the -fno-omit-frame-pointer option
when compiling.

Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Elling <Richard.Elling@RichardElling.com>
Closes #8617
2019-04-14 11:04:54 -07:00
Brian Behlendorf fed90353d7
Support -fsanitize=address with --enable-asan
When --enable-asan is provided to configure then build all user
space components with fsanitize=address.  For kernel support
use the Linux KASAN feature instead.

https://github.com/google/sanitizers/wiki/AddressSanitizer

When using gcc version 4.8 any test case which intentionally
generates a core dump will fail when using --enable-asan.
The default behavior is to disable core dumps and only newer
versions allow this behavior to be controled at run time with
the ASAN_OPTIONS environment variable.

Additionally, this patch includes some build system cleanup.

* Rules.am updated to set the minimum AM_CFLAGS, AM_CPPFLAGS,
  and AM_LDFLAGS.  Any additional flags should be added on a
  per-Makefile basic.  The --enable-debug and --enable-asan
  options apply to all user space binaries and libraries.

* Compiler checks consolidated in always-compiler-options.m4
  and renamed for consistency.

* -fstack-check compiler flag was removed, this functionality
  is provided by asan when configured with --enable-asan.

* Split DEBUG_CFLAGS in to DEBUG_CFLAGS, DEBUG_CPPFLAGS, and
  DEBUG_LDFLAGS.

* Moved default kernel build flags in to module/Makefile.in and
  split in to ZFS_MODULE_CFLAGS and ZFS_MODULE_CPPFLAGS.  These
  flags are set with the standard ccflags-y kbuild mechanism.

* -Wframe-larger-than checks applied only to binaries or
  libraries which include source files which are built in
  both user space and kernel space.  This restriction is
  relaxed for user space only utilities.

* -Wno-unused-but-set-variable applied only to libzfs and
  libzpool.  The remaining warnings are the result of an
  ASSERT using a variable when is always declared.

* -D_POSIX_PTHREAD_SEMANTICS and -D__EXTENSIONS__ dropped
  because they are Solaris specific and thus not needed.

* Ensure $GDB is defined as gdb by default in zloop.sh.

Signed-off-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7027
2018-01-10 10:49:27 -08:00
Prakash Surya acf044420b Add support for "--enable-code-coverage" option
This change adds support for a new option that can be passed to the
configure script: "--enable-code-coverage". Further, the "--enable-gcov"
option has been removed, as this new option provides the same
functionality (plus more).

When using this new option the following make targets are available:

 * check-code-coverage
 * code-coverage-capture
 * code-coverage-clean

Note: these make targets can only be run from the root of the project.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Closes #6670
2017-09-22 18:49:57 -07:00
Matthew Ahrens 4a5d7f8267 Allow c99 code to compile
Add the appropriate compiler flags to accept c99 code.  This will help to
minimize differences with upstream, and aid porting changes.  One change was
necessary in zvol.c because the DEFINE_IDA() macro does not work with the new
compiler flags.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Chunwei Chen <david.chen@osnexus.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #5756
2017-02-08 09:27:48 -08:00
Brian Behlendorf b58986eebf Use large stacks when available
While stack size will vary by architecture it has historically defaulted to
8K on x86_64 systems.  However, as of Linux 3.15 the default thread stack
size was increased to 16K.  These kernels are now the default in most non-
enterprise distributions which means we no longer need to assume 8K stacks.

This patch takes advantage of that fact by appropriately reverting stack
conservation changes which were made to ensure stability.  Changes which
may have had a negative impact on performance for certain workloads.  This
also has the side effect of bringing the code slightly more in line with
upstream.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes #4059
2015-12-07 12:20:43 -08:00
Brian Behlendorf c2d17fd891 Disable gcc bool-compare warning
As of gcc version 5.1.1 a new boolean comparison warning has been
introduced.  This warning is harmless but is triggered several places
in the ZFS code base.  Because warnings are promoted to errors when
building with debugging enabled it is necessary to disable the warning
when using versions of gcc which automatically enabling this check.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-07-13 12:55:26 -07:00
Brian Behlendorf 1139491da7 Revert "Disable GCCs aggressive loop optimization"
This reverts commit 0f62f3f9ab.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2010
2014-07-22 09:56:55 -07:00
Chris Dunlap 07917db990 Add defs for makefile installation dir vars
Add macro definitions to AM_CPPFLAGS to propagate makefile installation
directory variables for libexecdir, runstatedir, sbindir, and
sysconfdir.

https://www.gnu.org/software/autoconf/manual/autoconf-2.69/html_node/Installation-Directory-Variables.html

  A corollary is that you should not use these variables except
  in makefiles. For instance, instead of trying to evaluate
  datadir in configure and hard-coding it in makefiles using e.g.,
  'AC_DEFINE_UNQUOTED([DATADIR], ["$datadir"], [Data directory.])',
  you should add -DDATADIR='$(datadir)' to your makefile's definition
  of CPPFLAGS (AM_CPPFLAGS if you are also using Automake).

The runstatedir directory is for "installing data files which the
programs modify while they run, that pertain to one specific machine,
and which need not persist longer than the execution of the program".

https://www.gnu.org/prep/standards/html_node/Directory-Variables.html

It will be defined by autoconf 2.70 or later, and default to
"$(localstatedir)/run".

http://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commit;h=a197431414088a417b407b9b20583b2e8f7363bd

Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2
2014-03-31 16:11:13 -07:00
Brian Behlendorf 0f62f3f9ab Disable GCCs aggressive loop optimization
GCC >+ 4.8's aggressive loop optimization breaks some of the iterators
over the dn_blkptr[] pseudo-array in dnode_phys. Since dn_blkptr[] is
defined as a single-element array, GCC believes an iterator can only
access index 0 and will unroll the loop into a single iteration.

One way to resolve the issue would be to cast the array to a pointer
and fix all the iterators that might break.  The only loop where it
is known to cause a problem is this loop in dmu_objset_write_ready():

    for (i = 0; i < dnp->dn_nblkptr; i++)
            bp->blk_fill += dnp->dn_blkptr[i].blk_fill;

In the common case where dn_nblkptr is 3, the loop is only executed a
single time and "i" is equal to 1 following the loop.

The specific breakage caused by this problem is that the blk_fill of
root block pointers wouldn't be set properly when more than one blkptr
is in use (when no indrect blocks are needed).

The simple reproducing sequence is:

zpool create tank /tank.img
zdb -ddddd tank 0

Notice that "fill=31", however, there are two L0 indirect blocks with
"F=31" and "F=5". The fill count should be 36 rather than 31. This
problem causes an assert to be hit in a simple "zdb tank" when built
with --enable-debug.

However, this approach was not taken because we need to be absolutely
sure we catch all instances of this unwanted optimization.  Therefore,
the build system has been updated to detect if GCC supports the
aggressive loop optimization.  If it does the optimization will be
explicitly disabled using the -fno-aggressive-loop-optimization option.

Original-fix-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2010
Closes #2051
2014-01-14 13:55:58 -08:00
Jan Engelhardt ecf76e3676 build: use CPPFLAGS
-D and -I are preprocessor flags, so should preferably be in the
appropriate variable.

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-04-02 10:48:26 -07:00
Brian Behlendorf 8a7e1ceefa Check for -Wno-unused-but-set-variable gcc support
Gcc versions 4.3.2 and earlier do not support the compiler flag
-Wno-unused-but-set-variable.  This can lead to build failures
on older Linux platforms such as Debian Lenny.  Since this is
an optional build argument this changes add a new autoconf check
for the option.  If it is supported by the installed version of
gcc then it is used otherwise it is omited.

See commit's 12c1acde76 and
79713039a2 for the reason the
-Wno-unused-but-set-variable options was originally added.
2011-06-14 14:43:22 -07:00
Brian Behlendorf 12c1acde76 Set -Wno-unused-but-set-variable globally
As of gcc-4.6 the option -Wunused-but-set-variable is enabled by
default.  While this is a useful warning there are numerous places
in the ZFS code when a variable is set and then only checked in an
ASSERT().  To avoid having to update every instance of this in the
code we now set -Wno-unused-but-set-variable to suppress the warning.

Additionally, when building with --enable-debug and -Werror set these
warning also become fatal.  We can reevaluate the suppression of these
error at a later time if it becomes an issue.  For now we are basically
just reverting to the previous gcc behavior.
2011-04-19 10:44:10 -07:00
Brian Behlendorf 6283f55ea1 Support custom build directories and move includes
One of the neat tricks an autoconf style project is capable of
is allow configurion/building in a directory other than the
source directory.  The major advantage to this is that you can
build the project various different ways while making changes
in a single source tree.

For example, this project is designed to work on various different
Linux distributions each of which work slightly differently.  This
means that changes need to verified on each of those supported
distributions perferably before the change is committed to the
public git repo.

Using nfs and custom build directories makes this much easier.
I now have a single source tree in nfs mounted on several different
systems each running a supported distribution.  When I make a
change to the source base I suspect may break things I can
concurrently build from the same source on all the systems each
in their own subdirectory.

wget -c http://github.com/downloads/behlendorf/zfs/zfs-x.y.z.tar.gz
tar -xzf zfs-x.y.z.tar.gz
cd zfs-x-y-z

------------------------- run concurrently ----------------------
<ubuntu system>  <fedora system>  <debian system>  <rhel6 system>
mkdir ubuntu     mkdir fedora     mkdir debian     mkdir rhel6
cd ubuntu        cd fedora        cd debian        cd rhel6
../configure     ../configure     ../configure     ../configure
make             make             make             make
make check       make check       make check       make check

This change also moves many of the include headers from individual
incude/sys directories under the modules directory in to a single
top level include directory.  This has the advantage of making
the build rules cleaner and logically it makes a bit more sense.
2010-09-08 12:38:56 -07:00
Brian Behlendorf c9c0d073da Add build system
Add autoconf style build infrastructure to the ZFS tree.  This
includes autogen.sh, configure.ac, m4 macros, some scripts/*,
and makefiles for all the core ZFS components.
2010-08-31 13:41:27 -07:00