This is primarily of use when a pool has lost its disk, while the user
doesn't care about any pending (or otherwise) transactions.
Implement various control methods to make this feasible:
- txg_wait can now take a NOSUSPEND flag, in which case the caller will
be alerted if their txg can't be committed. This is primarily of
interest for callers that would normally pass TXG_WAIT, but don't want
to wait if the pool becomes suspended, which allows unwinding in some
cases, specifically when one is attempting a non-forced export.
Without this, the non-forced export would preclude a forced export
by virtue of holding the namespace lock indefinitely.
- txg_wait also returns failure for TXG_WAIT users if a pool is actually
being force exported. Adjust most callers to tolerate this.
- spa_config_enter_flags now takes a NOSUSPEND flag to the same effect.
- DMU objset initiator which may be set on an objset being forcibly
exported / unmounted.
- SPA export initiator may be set on a pool being forcibly exported.
- DMU send/recv now use an interruption mechanism which relies on the
SPA export initiator being able to enumerate datasets and closing any
send/recv streams, causing their EINTR paths to be invoked.
- ZIO now has a cancel entry point, which tells all suspended zios to
fail, and which suppresses the failures for non-CANFAIL users.
- metaslab, etc. cleanup, which consists of simply throwing away any
changes that were not able to be synced out.
- Linux specific: introduce a new tunable,
zfs_forced_export_unmount_enabled, which allows the filesystem to
remain in a modified 'unmounted' state upon exiting zpl_umount_begin,
to achieve parity with FreeBSD and illumos,
which have VFS-level support for yanking filesystems out from under
users. However, this only helps when the user is actively performing
I/O, while not sitting on the filesystem. In particular, this allows
test #3 below to pass on Linux.
- Add basic logic to zpool to indicate a force-exporting pool, instead
of crashing due to lack of config, etc.
Add tests which cover the basic use cases:
- Force export while a send is in progress
- Force export while a recv is in progress
- Force export while POSIX I/O is in progress
This change modifies the libzfs ABI:
- New ZPOOL_STATUS_FORCE_EXPORTING zpool_status_t enum value.
- New field libzfs_force_export for libzfs_handle.
Signed-off-by: Will Andrews <will@firepipe.net>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Mariusz Zaborski <mariusz.zaborski@klarasystems.com>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Catalogics, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#3461
(cherry picked from commit 852e633772217d779a63e8c46fe3c5f81dd8960e)
They're later |=d with constants, but never reset
Caught by valgrind while investigating
https://github.com/openzfs/zfs/pull/12928#issuecomment-1007496550
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12954
Added errno mappings to unmount_one() in libzfs. Changed do_unmount()
implementation to return errno errors directly like is done for
do_mount() and others.
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes#11681
== 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#1603Closes#7692Closes#7943Closes#10300
When zfs_mount_at() fails to stat the mountpoint and can't create the
directory, we return an error with a message "failed to create
mountpoint" but there is no indication why it failed.
Add the error string from the syscall to the error aux message.
Update do_mount for Linux to return the errno instead of -1.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#10550
Allow zfs datasets to be mounted on Linux without relying on the
invocation of an external processes. This is the same behavior
which is implemented for FreeBSD.
Use of the libmount library was originally considered because it
provides functionality to properly lock and update the /etc/mtab
file. However, these days /etc/mtab is typically a symlink to
/proc/self/mounts so there's nothing to updated. Therefore, we
call mount(2) directly and avoid any additional dependencies.
If required the legacy behavior can be enabled by setting the
ZFS_MOUNT_HELPER environment variable. This may be needed in
environments where SELinux in enabled and the zfs binary does
not have mount permission.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Felix Dörre <felix@dogcraft.de>
#10294
Add the 'zfs jail/unjail' subcommands along with the relevant
documentation from FreeBSD. This feature is not supported on
Linux and still requires the match kernel ioctls which will
be included when the FreeBSD platform code is integrated.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@ixsystems.com>
Closes#9686
Factor Linux specific functionality out of libzfs.
Reviewed-by: Allan Jude <allanjude@freebsd.org>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Macy <mmacy@FreeBSD.org>
Closes#9377
Mariusz Zaborski
наб
Don Brady
George Wilson
Ryan Moeller
felixdoerre
Matthew Macy
Matthew Macy