OpenZFS on Linux and FreeBSD
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Richard Yao 6a42939fcd
Cleanup: Address Clang's static analyzer's unused code complaints
These were categorized as the following:

 * Dead assignment		23
 * Dead increment		4
 * Dead initialization		6
 * Dead nested assignment	18

Most of these are harmless, but since actual issues can hide among them,
we correct them.

That said, there were a few return values that were being ignored that
appeared to merit some correction:

 * `destroy_callback()` in `cmd/zfs/zfs_main.c` ignored the error from
   `destroy_batched()`. We handle it by returning -1 if there is an
   error.

 * `zfs_do_upgrade()` in `cmd/zfs/zfs_main.c` ignored the error from
   `zfs_for_each()`. We handle it by doing a binary OR of the error
   value from the subsequent `zfs_for_each()` call to the existing
   value. This is how errors are mostly handled inside `zfs_for_each()`.
   The error value here is passed to exit from the zfs command, so doing
   a binary or on it is better than what we did previously.

 * `get_zap_prop()` in `module/zfs/zcp_get.c` ignored the error from
   `dsl_prop_get_ds()` when the property is not of type string. We
   return an error when it does. There is a small concern that the
   `zfs_get_temporary_prop()` call would handle things, but in the case
   that it does not, we would be pushing an uninitialized numval onto
   the lua stack. It is expected that `dsl_prop_get_ds()` will succeed
   anytime that `zfs_get_temporary_prop()` does, so that not giving it a
   chance to fix things is not a problem.

 * `draid_merge_impl()` in `tests/zfs-tests/cmd/draid.c` used
   `nvlist_add_nvlist()` twice in ways in which errors are expected to
   be impossible, so we switch to `fnvlist_add_nvlist()`.

A few notable ones did not merit use of the return value, so we
suppressed it with `(void)`:

 * `write_free_diffs()` in `lib/libzfs/libzfs_diff.c` ignored the error
   value from `describe_free()`. A look through the commit history
   revealed that this was intentional.

 * `arc_evict_hdr()` in `module/zfs/arc.c` did not need to use the
   returned handle from `arc_hdr_realloc()` because it is already
   referenced in lists.

 * `spa_vdev_detach()` in `module/zfs/spa.c` has a comment explicitly
   saying not to use the error from `vdev_label_init()` because whatever
   causes the error could be the reason why a detach is being done.

Unfortunately, I am not presently able to analyze the kernel modules
with Clang's static analyzer, so I could have missed some cases of this.
In cases where reports were present in code that is duplicated between
Linux and FreeBSD, I made a conscious effort to fix the FreeBSD version
too.

After this commit is merged, regressions like dee8934 should become
extremely obvious with Clang's static analyzer since a regression would
appear in the results as the only instance of unused code. That assumes
that Coverity does not catch the issue first.

My local branch with fixes from all of my outstanding non-draft pull
requests shows 118 reports from Clang's static anlayzer after this
patch. That is down by 51 from 169.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Cedric Berger <cedric@precidata.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13986
2022-10-14 13:37:54 -07:00
.github CI: bump actions/upload-artifact to v3 2022-10-12 15:18:39 -07:00
cmd Cleanup: Address Clang's static analyzer's unused code complaints 2022-10-14 13:37:54 -07:00
config Linux: Remove ZFS_AC_KERNEL_SRC_MODULE_PARAM_CALL_CONST autotools check 2022-10-13 10:03:09 -07:00
contrib PAM: Fix unchecked return value from zfs_key_config_load() 2022-10-05 17:09:24 -07:00
etc etc: mask zfs-load-key.service 2022-10-12 15:27:55 -07:00
include Cleanup: 64-bit kernel module parameters should use fixed width types 2022-10-13 10:03:29 -07:00
lib Cleanup: Address Clang's static analyzer's unused code complaints 2022-10-14 13:37:54 -07:00
man Cleanup: 64-bit kernel module parameters should use fixed width types 2022-10-13 10:03:29 -07:00
module Cleanup: Address Clang's static analyzer's unused code complaints 2022-10-14 13:37:54 -07:00
rpm Add zilstat script to report zil kstats in a user friendly manner 2022-09-02 13:24:07 -07:00
scripts cstyle: Allow URLs in C++ comments 2022-10-13 11:05:05 -07:00
tests Cleanup: Address Clang's static analyzer's unused code complaints 2022-10-14 13:37:54 -07:00
udev Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
.editorconfig Add an .editorconfig; document git whitespace settings 2020-01-27 13:32:52 -08:00
.gitignore autoconf: use include directives instead of recursing down cmd 2022-05-10 10:18:38 -07:00
.gitmodules .gitmodules: link to openzfs github repository 2021-04-12 09:37:23 -07:00
AUTHORS Introduce BLAKE3 checksums as an OpenZFS feature 2022-06-08 15:55:57 -07:00
CODE_OF_CONDUCT.md Replace ZFS on Linux references with OpenZFS 2020-10-08 20:10:13 -07:00
COPYRIGHT Fix typos 2020-06-09 21:24:09 -07:00
LICENSE Update build system and packaging 2018-05-29 16:00:33 -07:00
META Linux 5.19 compat: META 2022-08-02 10:04:38 -07:00
Makefile.am Replace EXTRA_DIST with dist_noinst_DATA 2022-05-26 09:24:50 -07:00
NEWS Fix NEWS file 2020-08-26 21:44:41 -07:00
NOTICE Update build system and packaging 2018-05-29 16:00:33 -07:00
README.md README: Update OpenZFS website url 2022-01-06 16:25:01 -08:00
RELEASES.md Add RELEASES.md file 2021-04-02 16:33:40 -07:00
TEST Remove CI builder customization from TEST 2020-03-16 10:46:03 -07:00
autogen.sh autogen.sh: paper over automake <1.14's lack of %reldir% support 2022-05-10 10:20:46 -07:00
configure.ac Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
copy-builtin copy-builtin: add hooks with sed/>> 2022-05-10 10:17:43 -07:00
zfs.release.in Move zfs.release generation to configure step 2012-07-12 12:22:51 -07:00

README.md

img

OpenZFS is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the OpenZFS community. This repository contains the code for running OpenZFS on Linux and FreeBSD.

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Official Resources

Installation

Full documentation for installing OpenZFS on your favorite operating system can be found at the Getting Started Page.

Contribute & Develop

We have a separate document with contribution guidelines.

We have a Code of Conduct.

Release

OpenZFS is released under a CDDL license. For more details see the NOTICE, LICENSE and COPYRIGHT files; UCRL-CODE-235197

Supported Kernels

  • The META file contains the officially recognized supported Linux kernel versions.
  • Supported FreeBSD versions are any supported branches and releases starting from 12.2-RELEASE.