In some environments, just making the .zfs control dir hidden from sight
might not be enough. In particular, the following scenarios might
warrant not allowing access at all:
- old snapshots with wrong permissions/ownership
- old snapshots with exploitable setuid/setgid binaries
- old snapshots with sensitive contents
Introducing a new 'disabled' value that not only hides the control dir,
but prevents access to its contents by returning ENOENT solves all of
the above.
The new property value takes advantage of 'iuv' semantics ("ignore
unknown value") to automatically fall back to the old default value when
a pool is accessed by an older version of ZFS that doesn't yet know
about 'disabled' semantics.
I think that technically the zfs_dirlook change is enough to prevent
access, but preventing lookups and dir entries in an already opened .zfs
handle might also be a good idea to prevent races when modifying the
property at runtime.
Add zfs_snapshot_no_setuid parameter to control whether automatically
mounted snapshots have the setuid mount option set or not.
this could be considered a partial fix for one of the scenarios
mentioned in desired.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Co-authored-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Closes#3963Closes#16587
torvalds/linux@09022bc196 removes the flag, and the corresponding
SetPageError() and ClearPageError() macros, with no replacement offered.
Going back through the upstream history, use of this flag has been
gradually removed over the last year as part of the long tail of
converting everything to folios. Interesting tidbit comments from
torvalds/linux@29e9412b25 and torvalds/linux@420e05d0de suggest that
this flag has not been used meaningfully since page writeback failures
started being recorded in errseq_t instead (the whole "fsyncgate" thing,
~2017, around torvalds/linux@8ed1e46aaf).
Given that, it's possible that since perhaps Linux 4.13 we haven't been
getting anything by setting the flag. I don't know if that's true and/or
if there's something we should be doing instead, but my gut feel is that
its probably fine we only use the page cache as a proxy to allow mmap()
to work, rather than backing IO with it.
As such, I'm expecting that removing this will do no harm, but I'm
leaving it in for older kernels to maintain status quo, and if there is
an overall better way, that is left for a future change.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16582
See torvalds/linux@a2b80ce87a. It claims the task arg is always
`current`, and so it is with us, so this is a safe change to make. The
only spanner is that we also support the older pre-5.17 3-arg
dequeue_signal() which had different meaning, so we have to check the
types to get the right one.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16582
This patch adds the ability for zfs to support file/dir name up to 1023
bytes. This number is chosen so we can support up to 255 4-byte
characters. This new feature is represented by the new feature flag
feature@longname.
A new dataset property "longname" is also introduced to toggle longname
support for each dataset individually. This property can be disabled,
even if it contains longname files. In such case, new file cannot be
created with longname but existing longname files can still be looked
up.
Note that, to my knowledge native Linux filesystems don't support name
longer than 255 bytes. So there might be programs not able to work with
longname.
Note that NFS server may needs to use exportfs_get_name to reconnect
dentries, and the buffer being passed is limit to NAME_MAX+1 (256). So
NFS may not work when longname is enabled.
Note, FreeBSD vfs layer imposes a limit of 255 name lengh, so even
though we add code to support it here, it won't actually work.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Closes#15921
This patch is preparatory work for long name feature. It changes all
users of zap_attribute_t to allocate it from kmem instead of stack. It
also make zap_attribute_t and zap_name_t structure variable length.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Closes#15921
Linux page migration code won't wait for writeback to complete unless
it needs to call release_folio. Call SetPagePrivate wherever
PageUptodate is set and define .release_folio, to cause
fallback_migrate_folio to wait for us.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: tstabrawa <59430211+tstabrawa@users.noreply.github.com>
Closes#15140Closes#16568
Since the person using the kernel may not be the person who built it,
show a warning at module load too, in case they aren't aware that it
might be weird.
Reviewed-by: Robert Evans <evansr@google.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#15986
It's the main recommendation to set xattr=sa
even in man pages, so let's set it by default.
xattr=sa don't use feature flag, so in the worst
case we'll have non-readable xattrs by other
non-openzfs platforms.
Non-overridden default `xattr` prop of existing pools
will automatically use `sa` after this commit too.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes#15147
Just nice and simple, with room to grow.
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16492
For now, userspace has no znode implementation. Some of the property and
path handling code is used there though and is the same on all
platforms, so we only need a single copy of it.
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16492
The Linux arc_os.c carries userspace and kernel code, with very little
overlap between the two. This lifts the userspace parts out into a
separate arc_os.c for libzpool and removes it from the Linux side.
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16492
All kernels we support have compound pages that work the way we would
like. However, this code is new and this knowledge was hard won, so I'd
like to leave the description and option there for a little while, even
if it can only be disabled with a recompile.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16545
Following 2b069768a (#16479), anything gated on a kernel version before
4.18 can be always included/excluded.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16545
So that we can get actual benefit from last commit.
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Shengqi Chen <harry-chen@outlook.com>
Closes#16131Closes#16483
We only use it on a specific way: to punch a hole in (make sparse) a
region of a file, in order to implement TRIM-like behaviour.
So, call the op "deallocate", and move the Linux-style mode flags down
into the Linux implementation, since they're an implementation detail.
FreeBSD gets a no-op stub (for the moment).
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16496
get_user_pages_unlocked() had stabilised by 4.9.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16479
