Commit Graph

6 Commits

Author SHA1 Message Date
Ryan Moeller
37325e4749
Linux: Prevent destruction while showing mount devname
Use ZFS_ENTER and ZFS_EXIT to protect datasets while their mount
devname is being retrieved.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10892
Closes #10927
2020-09-15 15:40:03 -07:00
Ryan Moeller
7b4e27232d
Add 'zfs rename -u' to rename without remounting
Allow to rename file systems without remounting if it is possible.
It is possible for file systems with 'mountpoint' property set to
'legacy' or 'none' - we don't have to change mount directory for them.
Currently such file systems are unmounted on rename and not even
mounted back.

This introduces layering violation, as we need to update
'f_mntfromname' field in statfs structure related to mountpoint (for
the dataset we are renaming and all its children).

In my opinion it is worth it, as it allow to update FreeBSD in even
cleaner way - in ZFS-only configuration root file system is ZFS file
system with 'mountpoint' property set to 'legacy'. If root dataset is
named system/rootfs, we can snapshot it (system/rootfs@upgrade), clone
it (system/oldrootfs), update FreeBSD and if it doesn't boot we can
boot back from system/oldrootfs and rename it back to system/rootfs
while it is mounted as /. Before it was not possible, because
unmounting / was not possible.

Authored by: Pawel Jakub Dawidek <pjd@FreeBSD.org>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported by: Matt Macy <mmacy@freebsd.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10839
2020-09-01 16:14:16 -07:00
adilger
f734301d22
linux: add basic fallocate(mode=0/2) compatibility
Implement semi-compatible functionality for mode=0 (preallocation)
and mode=FALLOC_FL_KEEP_SIZE (preallocation beyond EOF) for ZPL.

Since ZFS does COW and snapshots, preallocating blocks for a file
cannot guarantee that writes to the file will not run out of space.
Even if the first overwrite was guaranteed, it would not handle any
later overwrite of blocks due to COW, so strict compliance is futile.
Instead, make a best-effort check that at least enough free space is
currently available in the pool (with a bit of margin), then create
a sparse file of the requested size and continue on with life.

This does not handle all cases (e.g. several fallocate() calls before
writing into the files when the filesystem is nearly full), which
would require a more complex mechanism to be implemented, probably
based on a modified version of dmu_prealloc(), but is usable as-is.

A new module option zfs_fallocate_reserve_percent is used to control
the reserve margin for any single fallocate call.  By default, this
is 110% of the requested preallocation size, so an additional 10% of
available space is reserved for overhead to allow the application a
good chance of finishing the write when the fallocate() succeeds.
If the heuristics of this basic fallocate implementation are not
desirable, the old non-functional behavior of returning EOPNOTSUPP
for calls can be restored by setting zfs_fallocate_reserve_percent=0.

The parameter of zfs_statvfs() is changed to take an inode instead
of a dentry, since no dentry is available in zfs_fallocate_common().

A few tests from @behlendorf cover basic fallocate functionality.

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Arshad Hussain <arshad.super@gmail.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Issue #326
Closes #10408
2020-06-18 11:22:11 -07:00
Matthew Macy
657ce25357 Eliminate Linux specific inode usage from common code
Change many of the znops routines to take a znode rather
than an inode so that zfs_replay code can be largely shared
and in the future the much of the znops code may be shared.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9708
2019-12-11 11:53:57 -08:00
Brian Behlendorf
066e825221
Linux compat: Minimum kernel version 3.10
Increase the minimum supported kernel version from 2.6.32 to 3.10.
This removes support for the following Linux enterprise distributions.

    Distribution     | Kernel | End of Life
    ---------------- | ------ | -------------
    Ubuntu 12.04 LTS | 3.2    | Apr 28, 2017
    SLES 11          | 3.0    | Mar 32, 2019
    RHEL / CentOS 6  | 2.6.32 | Nov 30, 2020

The following changes were made as part of removing support.

* Updated `configure` to enforce a minimum kernel version as
  specified in the META file (Linux-Minimum: 3.10).

    configure: error:
        *** Cannot build against kernel version 2.6.32.
        *** The minimum supported kernel version is 3.10.

* Removed all `configure` kABI checks and matching C code for
  interfaces which solely predate the Linux 3.10 kernel.

* Updated all `configure` kABI checks to fail when an interface is
  missing which was in the 3.10 kernel up to the latest 5.1 kernel.
  Removed the HAVE_* preprocessor defines for these checks and
  updated the code to unconditionally use the verified interface.

* Inverted the detection logic in several kABI checks to match
  the new interface as it appears in 3.10 and newer and not the
  legacy interface.

* Consolidated the following checks in to individual files. Due
  the large number of changes in the checks it made sense to handle
  this now.  It would be desirable to group other related checks in
  the same fashion, but this as left as future work.

  - config/kernel-blkdev.m4 - Block device kABI checks
  - config/kernel-blk-queue.m4 - Block queue kABI checks
  - config/kernel-bio.m4 - Bio interface kABI checks

* Removed the kABI checks for sops->nr_cached_objects() and
  sops->free_cached_objects().  These interfaces are currently unused.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #9566
2019-11-12 08:59:06 -08:00
Matthew Macy
bced7e3aaa OpenZFS restructuring - move platform specific sources
Move platform specific Linux source under module/os/linux/
and update the build system accordingly.  Additional code
restructuring will follow to make the common code fully
portable.
    
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Macy <mmacy@FreeBSD.org>
Closes #9206
2019-09-06 11:26:26 -07:00