Commit Graph

4 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
Dimitri John Ledkov 5bf81fea2f Upgrade to libabigail 2.0.0
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Closes #12722
Closes #12739
2021-11-05 07:59:40 -07:00
George Melikov 5331e2d216 Update ABI files via new libabigail version
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes #12529
2021-09-14 15:40:12 -07:00
Brian Behlendorf 82611cdfe5 Add ABI snapshot
Add a snapshot of the current ABI using libabigail-1.7-2.  The
included ABI passes `make checkabi` for CentOS 7, Fedora 33,
Debian 10, and Ubuntu 20.04.  This covers a fairly wide range
of glibc, gcc, and libabigail versions plus other changes which
are platform specific.

Reviewed-by: Antonio Russo <aerusso@aerusso.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #11144
2020-11-17 09:21:39 -08:00