Various admin operations will be invoked by some userspace task, but the
work will be done on a separate kernel thread at a later time. Snapshots
are an example, which are triggered through zfs_ioc_snapshot() ->
dsl_dataset_snapshot(), but the actual work is from a task dispatched to
dp_sync_taskq.
Many such tasks end up in dsl_enforce_ds_ss_limits(), where various
limits and permissions are enforced. Among other things, it is necessary
to ensure that the invoking task (that is, the user) has permission to
do things. We can't simply check if the running task has permission; it
is a privileged kernel thread, which can do anything.
However, in the general case it's not safe to simply query the task for
its permissions at the check time, as the task may not exist any more,
or its permissions may have changed since it was first invoked. So
instead, we capture the permissions by saving CRED() in the user task,
and then using it for the check through the secpolicy_* functions.
The current code calls CRED() to get the credential, which gets a
pointer to the cred_t inside the current task and passes it to the
worker task. However, it doesn't take a reference to the cred_t, and so
expects that it won't change, and that the task continues to exist. In
practice that is always the case, because we don't let the calling task
return from the kernel until the work is done.
For Linux, we also take a reference to the current task, because the
Linux credential APIs for the most part do not check an arbitrary
credential, but rather, query what a task can do. See
secpolicy_zfs_proc(). Again, we don't take a reference on the task, just
a pointer to it.
We change to calling crhold() on the task credential, and crfree() when
we're done with it. This ensures it stays alive and unchanged for the
duration of the call.
On the Linux side, we change the main policy checking function
priv_policy_ns() to use override_creds()/revert_creds() if necessary to
make the provided credential active in the current task, allowing the
standard task-permission APIs to do the needed check. Since the task
pointer is no longer required, this lets us entirely remove
secpolicy_zfs_proc() and the need to carry a task pointer around as
well.
Sponsored-by: https://despairlabs.com/sponsor/
Signed-off-by: Rob Norris <robn@despairlabs.com>
Reviewed-by: Pavel Snajdr <snajpa@snajpa.net>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Kyle Evans <kevans@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
I've found that QEMU/KVM guest memory accounted as shared also
included into NR_FILE_PAGES. But it is actually a non-evictable
anonymous memory. Using it as a base for zfs_arc_pc_percent
parameter makes ARC to ignore shrinker requests while page cache
does not really have anything to evict, ending up in OOM killer
killing the QEMU process.
Instead use of NR_ACTIVE_FILE + NR_INACTIVE_FILE should represent
the part of a page cache that is actually evictable, which should
be safer to use as a reference for ARC scaling.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Reviewed-by: Pavel Snajdr <snajpa@snajpa.net>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#17334
(cherry picked from commit 0aa83dce99)
since 4.10, bio->bi_opf needs to be checked to determine all kinds of
flush requests. this was the case prior to the commit referenced below,
but the order of ifdefs was not the usual one (newest up top), which
might have caused this to slip through.
this fixes a regression when using zvols as Qemu block devices, but
might have broken other use cases as well. the symptoms are that all
sync writes from within a VM configured to use such a virtual block
devices are ignored and treated as async writes by the host ZFS layer.
this can be verified using fio in sync mode inside the VM, for example
with
fio \
--filename=/dev/sda --ioengine=libaio --loops=1 --size=10G \
--time_based --runtime=60 --group_reporting --stonewall --name=cc1 \
--description="CC1" --rw=write --bs=4k --direct=1 --iodepth=1 \
--numjobs=1 --sync=1
which shows an IOPS number way above what the physical device underneath
supports, with "zpool iostat -r 1" on the hypervisor side showing no
sync IO occuring during the benchmark.
with the regression fixed, both fio inside the VM and the IO stats on
the host show the expected numbers.
Fixes: 846b598519
"config: remove HAVE_REQ_OP_* and HAVE_REQ_*"
Signed-off-by: Fabian-Gruenbichler <f.gruenbichler@proxmox.com>
Co-authored-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Closes#17131
(cherry picked from commit 41823a0ede)
For UIO_ITER, we are just wrapping a kernel iterator. It will take care
of its own offsets if necessary. We don't need to do anything, and if we
do try to do anything with it (like advancing the iterator by the skip
in zfs_uio_advance) we're just confusing the kernel iterator, ending up
at the wrong position or worse, off the end of the memory region.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#17298
(cherry picked from commit 2ee5b51a57)
Some compiler/versions warn these typedefs according to #16660.
The platform specific header sys/abd_os.h shouldn't define or use abd_t,
as it's defined in its non-platform specific consumer sys/abd.h.
Do the same as what FreeBSD header does.
Original-patch-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Rob Norris <robn@despairlabs.com>
(cherry picked from commit a9851ea3dd)
Co-authored-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
This fixes a serious performance problem with NFS handling of large
directories, as the new get_name code is much more efficient than the
default zfs_readdir. This is actually part of
20232ecfaa in 2.3. But I've taken only
the minimum code to implement get_name, and not the rest of the long
name changes.
Signed-off-by: Charles Hedrick <hedrick@rutgers.edu>
Co-authored-by: Charles L. Hedrick <hedrick@ncommunis.cs.rutgers.edu>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
These members have directly references to the global variables
exposed by the kernel. They are not going to be changed by this
kernel module.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Zhenlei Huang <zlei@FreeBSD.org>
Closes#16210
The FreeBSD linux/compiler.h in OpenZFS was copied from a very old
version of FreeBSD's linuxkpi's linux/compiler.h. There's no need for
this duplication. Use FreeBSD's linuxkpi version instead, and provide
zfs_fallthrough to augment it (it's all that's needed). Use #pragma once
to avoid naming issues for guard variables. Since this is a complete
rewrite, use my copyright here (the original code in FreeBSD still
credits everybody). This works back at least to FreeBSD 12.4, which
is not out of support, and all newer releases.
Remove extra copies of macros that were defined elsewhere, but are now
properly defined in LinuxKPI so are redundant.
Sponsored-by: Netflix
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Closes#16650
Being able to print custom debug information on assert trip
seems useful.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#15792
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
linux/torvalds@11068e0b64 removes it, suggesting this was a always
there as a helper to handle concurrent seeks, which all filesystems now
handle themselves if necessary.
Without looking into the mechanism, I can imagine how it might have been
used, but we have always set it to zero and never read from it,
presumably because we've always tracked per-caller position through the
znode anyway. So I don't see how there can be any functional change for
us by removing it. I've stayed conservative though and left it in for
older kernels, since its clearly not hurting anything there.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16582
torvalds/linux@641bb4394f asserts that this is a static flag, not
intended to be variable per-file, so it moves it to
file_operations instead. We just change our check to follow.
No configure check is necessary because FOP_UNSIGNED_OFFSET didn't exist
before this commit, and FMODE_UNSIGNED_OFFSET flag is removed in the
same commit, so there's no chance of a conflict.
It's not clear to me that we need this check at all, as we never set
this flag on our own files, and I can't see any way that our llseek
handler could recieve a file from another filesystem. But, the whole
zpl_llseek() has a number of opportunities for pleasing cleanup that are
nothing to do with this change, so I'll leave that 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
torvalds/linux@b2e7456b5c makes kmem_cache_create() a macro, which
gets in the way of our our own redefinition, so we undef the macro first
for our own clients. This follows what we did for kmem_cache_alloc(),
see e951dba48.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16582
This includes the last 12.x release (now EOL) and 13.0 development
versions (<1300139).
Sponsored-by: https://despairlabs.com/sponsor/
Signed-off-by: Rob Norris <robn@despairlabs.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Removing the platform #ifdefs from shared headers in favour of
per-platform headers. Makes abd_t much leaner, among other things.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16253
