Commit Graph

7 Commits

Author SHA1 Message Date
Mariusz Zaborski 40a9efd0e8 zfs: support force exporting pools
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)
2023-07-05 13:27:30 +00:00
Ryan Moeller 793dffb04e FreeBSD: Don't force xattr mount option
The kernel will use the xattr property by default when not overridden
by a mount option.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11997
2021-05-27 22:12:19 -07:00
Don Brady f5ada6538d
Return finer grain errors in libzfs unmount_one
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
2021-03-08 08:46:45 -08:00
Arvind Sankar 60356b1a21 Add include files for prototypes
Include the header with prototypes in the file that provides definitions
as well, to catch any mismatch between prototype 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 12:21:25 -07:00
Arvind Sankar c3fe42aabd Remove dead code
Delete unused functions.

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 12:21:18 -07:00
felixdoerre 501a1511ae
mount: use the mount syscall directly
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
2020-05-20 18:02:41 -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