Commit Graph

6 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
наб d7e6f293da Modernise/fix/rewrite unlinted manpages
zpool-destroy.8: flatten, fix description
zfs-wait.8: flatten, fix description, use list for events
zpool-reguid.8: flatten, fix description
zpool-history.8: flatten, fix description
zpool-export.8: flatten, fix description, remove -f "unmount" reference
  AFAICT no such command exists even in Illumos (as of today, anyway),
  and we definitely don't call it
zpool-labelclear.8: flatten, fix description
zpool-features.5: modernise
spl-module-parameters.5: modernise
zfs-mount-generator.8: rewrite
zfs-module-parameters.5: modernise

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12169
2021-06-09 13:05:34 -07:00
xtouqh 1e36af8c7b
Properly format NAME subsection of zfs/zpool subcommands
Use proper names (i.e. zfs-allow and zpool-add) in NAME subsections
of zfs/zpool subcommands instead of current "pretty-printed" ones as
makewhatis utilities (or some implementations of it, namely the one
from mandoc suite used in FreeBSD) look not only at the document title
but also in NAME subsection, adding zfs(8)/zpool(8) to search results
which is not correct. (Common sense and other utilities splitting
subcommands in multiple man pages, e.g. git, do the same.)

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: xtouqh <xtouqh@hotmail.com>
Closes #11086
2020-10-22 11:28:10 -07:00
Ryan Moeller 6706552ea6
Remove hard coded "Linux" OS from manpages
The recommended practice for `.Os` on FreeBSD is to not specify any
arguments.  The correct OS name is used automatically.

Oddly enough, on the Linux distro I tested this on (CentOS 7), the man
pager defaulted to displaying "BSD" as the OS rather than "Linux".  To
accommodate this, tack " Linux" back on in an install hook on Linux.
This is much simpler than removing it for FreeBSD when vendored in the
base system.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10760
2020-08-21 11:55:47 -07:00
Mariusz Zaborski 89adffb7bc
Add notice that forcefully unmount is not supported on Linux
The Linux VFS will never allow a filesystem which is in use to
be unmounted.  This behavior differs from other platforms like
FreeBSD which allow a filesystem to be force unmounted.  This 
will result in errors being returned to applications actively
using the filesystem.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mariusz Zaborski <oshogbo@vexillium.org>
Closes #10013
2020-02-18 13:36:23 -08:00
Ross Williams c5ebfbbe19 Reorganize zpool(8) man page into sections
Moved subcommand topics into individual manpages. Reordered and 
grouped the list of subcommands by topic.

Moved concepts overview to `zpoolconcepts.8` and the long list of
available pool properties to `zpoolprops.8`.

Internal cross-references copied from `zpool.8` needed to be 
converted to `.Xr` external references to new subcommand manual 
pages.

Move `autotrim` into lexical order, autotrim tacked onto the end
of a list. Now it is in alphabetical order.

Clarify attach/detach description. Description was too specific to
command syntax. Overview clarifies reason for attaching or detaching
a device.

Clarify replace description, don't refer to subcommand arguments.

Clarify split command description, say what split actually does and
why you'd want to do it.

Clarify description of upgrade, and simplify the zpool.8 wording of
the zpool-upgrade(8) description.

Clarify description of import, detail what zpool-import(8) actually 
does.

Add appropriate SEE ALSO sections. Divided zpool subcommand manual 
pages need their own SEE ALSO sections. Also modified fsck.zfs.8 
to point directly to zfs-scrub.8 and zed.8.in to include a direct
reference to zfs-events.8

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ross Williams <ross@ross-williams.net>
Closes #9564
2019-11-13 09:21:07 -08:00