Commit Graph

14 Commits

Author SHA1 Message Date
Richard Yao dcce0dc5f0
Fix oversights from 4170ae4e
4170ae4ea6 was intended to tackle TOCTOU
race conditions reported by CodeQL, but as an oversight, a file
descriptor was not closed and some comments were not updated.
Interestingly, CodeQL did not complain about the file descriptor leak,
so there is room for improvement in how we configure it to try to detect
this issue so that we get early warning about this.

In addition, an optimization opportunity was missed by mistake in
lib/libshare/os/linux/smb.c, which prevented us from truly closing the
TOCTOU race. This was also caught by Coverity.

Reported-by: Coverity (CID 1524424)
Reported-by: Coverity (CID 1526804)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14109
2022-10-31 10:01:04 -07:00
Richard Yao 4170ae4ea6 Fix TOCTOU race conditions reported by CodeQL and Coverity
CodeQL and Coverity both complained about:

 * lib/libshare/os/linux/smb.c
 * tests/zfs-tests/cmd/mmapwrite.c
 	* twice
 * tests/zfs-tests/tests/functional/tmpfile/tmpfile_002_pos.c
 * tests/zfs-tests/tests/functional/tmpfile/tmpfile_stat_mode.c
	* coverity had a second complaint that CodeQL did not have
 * tests/zfs-tests/cmd/suid_write_to_file.c
	* Coverity had two complaints and CodeQL had one complaint, both
	  differed. The CodeQL complaint is about the main point of the
	  test, so it is not fixable without a hack involving `fork()`.

The issues reported by CodeQL are fixed, with the exception of the last
one, which is deemed to be a false positive that is too much trouble to
wrokaround. The issues reported by Coverity were only fixed if CodeQL
complained about them.

There were issues reported by Coverity in a number of other files that
were not reported by CodeQL, but fixing the CodeQL complaints is
considered a priority since we want to integrate it into a github
workflow, so the remaining Coverity complaints are left for future work.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14098
2022-10-29 13:04:10 -07:00
Tino Reichardt 1d3ba0bf01
Replace dead opensolaris.org license link
The commit replaces all findings of the link:
http://www.opensolaris.org/os/licensing with this one:
https://opensource.org/licenses/CDDL-1.0

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes #13619
2022-07-11 14:16:13 -07:00
наб e02d84d3a5
linux: libshare: smb: don't swallow net(1) errors
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13191
Closes #13470
2022-05-18 15:56:38 -07:00
наб 086af23e68 linux: libshare/smb: cache smb_available
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13165
2022-05-12 09:27:08 -07:00
наб 471e9a108e Publish libshare protocols, use enum-based API
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13165
2022-05-12 09:26:38 -07:00
наб 63ce6dd988 libshare: use AVL tree with static data, pass all data in arguments
This makes it so we don't leak a consistent 64 bytes anymore,
makes the searches simpler and faster, removes /all allocations/
from the driver (quite trivially, since they were absolutely needless),
and makes libshare thread-safe (except, maybe, linux/smb, but that only
does pointer-width loads/stores so it's also mostly fine, except for
leaking smb_shares)

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13165
2022-05-12 09:26:25 -07:00
наб 2faf05612f libshare/smb: cleanup
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13165
2022-05-12 09:26:18 -07:00
наб 56692e77e2 linux: libshare: smb: fix more than one smb_is_share_active() call
This also fixes zfs_unshare_006_pos, which exposed this

Fixes: 2f71caf2d9 ("Allow zfs unshare
 <protocol> -a")

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13259
2022-04-01 18:02:24 -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 c53f2e9b50 libshare: nfs: open temporary file once
Reviewed-by: Don Brady <don.brady@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12067
2021-12-17 12:53:54 -08:00
наб 5d1a32a542 linux/libshare: smb: don't leak share name in smb_disable_share_one()
Fixes: 645fb9cc21 "Implemented sharing datasets via SMB using libshare"

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12015
2021-05-21 10:16:18 -07:00
наб 10b575d04c lib/: set O_CLOEXEC on all fds
As found by
  git grep -E '(open|setmntent|pipe2?)\(' |
    grep -vE '((zfs|zpool)_|fd|dl|lzc_re|pidfile_|g_)open\('

FreeBSD's pidfile_open() says nothing about the flags of the files it
opens, but we can't do anything about it anyway; the implementation does
open all files with O_CLOEXEC

Consider this output with zpool.d/media appended with
"pid=$$; (ls -l /proc/$pid/fd > /dev/tty)":
  $ /sbin/zpool iostat -vc media
  lrwx------ 0 -> /dev/pts/0
  l-wx------ 1 -> 'pipe:[3278500]'
  l-wx------ 2 -> /dev/null
  lrwx------ 3 -> /dev/zfs
  lr-x------ 4 -> /proc/31895/mounts
  lrwx------ 5 -> /dev/zfs
  lr-x------ 10 -> /usr/lib/zfs-linux/zpool.d/media
vs
  $ ./zpool iostat -vc vendor,upath,iostat,media
  lrwx------ 0 -> /dev/pts/0
  l-wx------ 1 -> 'pipe:[3279887]'
  l-wx------ 2 -> /dev/null
  lr-x------ 10 -> /usr/lib/zfs-linux/zpool.d/media

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11866
2021-04-11 15:45:59 -07:00
George Wilson c15d36c674
Remove dependency on sharetab file and refactor sharing logic
== Motivation and Context

The current implementation of 'sharenfs' and 'sharesmb' relies on
the use of the sharetab file. The use of this file is os-specific
and not required by linux or freebsd. Currently the code must
maintain updates to this file which adds complexity and presents
a significant performance impact when sharing many datasets. In
addition, concurrently running 'zfs sharenfs' command results in
missing entries in the sharetab file leading to unexpected failures.

== Description

This change removes the sharetab logic from the linux and freebsd
implementation of 'sharenfs' and 'sharesmb'. It still preserves an
os-specific library which contains the logic required for sharing
NFS or SMB. The following entry points exist in the vastly simplified
libshare library:

- sa_enable_share -- shares a dataset but may not commit the change
- sa_disable_share -- unshares a dataset but may not commit the change
- sa_is_shared -- determine if a dataset is shared
- sa_commit_share -- notify NFS/SMB subsystem to commit the shares
- sa_validate_shareopts -- determine if sharing options are valid

The sa_commit_share entry point is provided as a performance enhancement
and is not required. The sa_enable_share/sa_disable_share may commit
the share as part of the implementation. Libshare provides a framework
for both NFS and SMB but some operating systems may not fully support
these protocols or all features of the protocol.

NFS Operation:
For linux, libshare updates /etc/exports.d/zfs.exports to add
and remove shares and then commits the changes by invoking
'exportfs -r'. This file, is automatically read by the kernel NFS
implementation which makes for better integration with the NFS systemd
service. For FreeBSD, libshare updates /etc/zfs/exports to add and
remove shares and then commits the changes by sending a SIGHUP to
mountd.

SMB Operation:
For linux, libshare adds and removes files in /var/lib/samba/usershares
by calling the 'net' command directly. There is no need to commit the
changes. FreeBSD does not support SMB.

== Performance Results

To test sharing performance we created a pool with an increasing number
of datasets and invoked various zfs actions that would enable and
disable sharing. The performance testing was limited to NFS sharing.
The following tests were performed on an 8 vCPU system with 128GB and
a pool comprised of 4 50GB SSDs:

Scale testing:
- Share all filesystems in parallel -- zfs sharenfs=on <dataset> &
- Unshare all filesystems in parallel -- zfs sharenfs=off <dataset> &

Functional testing:
- share each filesystem serially -- zfs share -a
- unshare each filesystem serially -- zfs unshare -a
- reset sharenfs property and unshare -- zfs inherit -r sharenfs <pool>

For 'zfs sharenfs=on' scale testing we saw an average reduction in time
of 89.43% and for 'zfs sharenfs=off' we saw an average reduction in time
of 83.36%.

Functional testing also shows a huge improvement:
- zfs share -- 97.97% reduction in time
- zfs unshare -- 96.47% reduction in time
- zfs inhert -r sharenfs -- 99.01% reduction in time

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Bryant G. Ly <bryangly@gmail.com>
Signed-off-by: George Wilson <gwilson@delphix.com>
External-Issue: DLPX-68690
Closes #1603
Closes #7692
Closes #7943
Closes #10300
2020-07-13 09:19:18 -07:00