OpenZFS on Linux and FreeBSD
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Christian Schwarz df000276b8 zfs_domount: fix double-disown of dataset / double-free of zfsvfs_t
Before this patch, in zfs_domount, if zfs_root or d_make_root fails, we
leave zfsvfs != NULL. This will lead to execution of the error handling
`if` statement at the `out` label, and hence to a call to
dmu_objset_disown and zfsvfs_free.

However, zfs_umount, which we call upon failure of zfs_root and
d_make_root already does dmu_objset_disown and zfsvfs_free.

I suppose this patch rather adds to the brittleness of this part of the
code base, but I don't want to invest more time in this right now.
To add a regression test, we'd need some kind of fault injection
facility for zfs_root or d_make_root, which doesn't exist right now.
And even then, I think that regression test would be too closely tied
to the implementation.

To repro the double-disown / double-free, do the following:
1. patch zfs_root to always return an error
2. mount a ZFS filesystem

Here's the stack trace you would see then:

  VERIFY3(ds->ds_owner == tag) failed (0000000000000000 == ffff9142361e8000)
  PANIC at dsl_dataset.c:1003:dsl_dataset_disown()
  Showing stack for process 28332
  CPU: 2 PID: 28332 Comm: zpool Tainted: G           O      5.10.103-1.nutanix.el7.x86_64 #1
  Call Trace:
   dump_stack+0x74/0x92
   spl_dumpstack+0x29/0x2b [spl]
   spl_panic+0xd4/0xfc [spl]
   dsl_dataset_disown+0xe9/0x150 [zfs]
   dmu_objset_disown+0xd6/0x150 [zfs]
   zfs_domount+0x17b/0x4b0 [zfs]
   zpl_mount+0x174/0x220 [zfs]
   legacy_get_tree+0x2b/0x50
   vfs_get_tree+0x2a/0xc0
   path_mount+0x2fa/0xa70
   do_mount+0x7c/0xa0
   __x64_sys_mount+0x8b/0xe0
   do_syscall_64+0x38/0x50
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Co-authored-by: Christian Schwarz <christian.schwarz@nutanix.com>
Signed-off-by: Christian Schwarz <christian.schwarz@nutanix.com>
Closes #14025
2022-11-01 12:42:32 -07:00
.github CI: bump actions/upload-artifact to v3 2022-11-01 12:38:22 -07:00
cmd zvol_wait logic may terminate prematurely 2022-11-01 12:35:36 -07:00
config Linux: Remove ZFS_AC_KERNEL_SRC_MODULE_PARAM_CALL_CONST autotools check 2022-11-01 12:42:01 -07:00
contrib contrib: dracut: zfs-snapshot-bootfs: exit status fix 2022-10-20 11:37:21 -07:00
etc etc: mask zfs-load-key.service 2022-10-12 15:29:21 -07:00
include Linux: Remove ZFS_AC_KERNEL_SRC_MODULE_PARAM_CALL_CONST autotools check 2022-11-01 12:42:01 -07:00
lib Ask libtool to stop hiding some errors 2022-09-21 16:12:14 -07:00
man Bring per_txg_dirty_frees_percent back to 30 2022-11-01 12:32:40 -07:00
module zfs_domount: fix double-disown of dataset / double-free of zfsvfs_t 2022-11-01 12:42:32 -07:00
rpm rpm: Silence "unversioned Obsoletes" warnings on EL 9 2022-09-13 17:50:59 -07:00
scripts Remove REMAKE_INITRD 2022-05-06 11:32:45 -07:00
tests Add options to zfs redundant_metadata property 2022-11-01 12:25:58 -07:00
udev Udev rules: use match (==) rather than assign (=) for PROGRAM 2021-09-14 12:23:10 -07:00
.editorconfig Add an .editorconfig; document git whitespace settings 2020-01-27 13:32:52 -08:00
.gitignore Add FreeBSD support to OpenZFS 2020-04-14 11:36:28 -07:00
.gitmodules .gitmodules: link to openzfs github repository 2021-04-14 13:23:08 -07:00
AUTHORS Add zstd support to zfs 2020-08-20 10:30:06 -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 Tag zfs-2.1.6 2022-09-28 17:25:10 -07:00
Makefile.am config: check for parallel(1), use it for cstyle 2022-09-14 11:23:25 -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 2022-02-16 17:58:55 -08:00
RELEASES.md Add RELEASES.md file 2021-04-07 13:26:58 -07:00
TEST Remove CI builder customization from TEST 2020-03-16 10:46:03 -07:00
autogen.sh Cause autogen.sh to fail if autoreconf fails 2018-07-06 09:27:37 -07:00
configure.ac Linux 5.16 compat: don't use XSTATE_XSAVE to save FPU state 2022-02-16 17:58:55 -08:00
copy-builtin copy-builtin: posix conformance 2021-05-10 12:18:54 -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.