While mounting ZFS root during boot on Linux distributions from initrd,
mount from busybox is effectively used which executes mount system call
directly. This skips the ZFS helper mount.zfs, which checks and enables
the mount options as specified in dataset properties. As a result,
datasets mounted during boot from initrd do not have correct mount
options as specified in ZFS dataset properties.
There has been an attempt to use mount.zfs in zfs initrd script,
responsible for mounting the ZFS root filesystem (PR#13305). This was
later reverted (PR#14908) after discovering that using mount.zfs breaks
mounting of snapshots on root (/) and other child datasets of root have
the same issue (Issue#9461).
This happens because switching from busybox mount to mount.zfs correctly
parses the mount options but also adds 'mntpoint=/root' to the mount
options, which is then prepended to the snapshot mountpoint in
'.zfs/snapshot'. '/root' is the directory on Debian with initramfs-tools
where root filesystem is mounted before pivot_root. When Linux runtime
is reached, trying to access the snapshots on root results in
automounting the snapshot on '/root/.zfs/*', which fails.
This commit attempts to fix the automounting of snapshots on root, while
using mount.zfs in initrd script. Since the mountpoint of dataset is
stored in vfs_mntpoint field, we can check if current mountpoint of
dataset and vfs_mntpoint are same or not. If they are not same, reset
the vfs_mntpoint field with current mountpoint. This fixes the
mountpoints of root dataset and children in respective vfs_mntpoint
fields when we try to access the snapshots of root dataset or its
children. With correct mountpoint for root dataset and children stored
in vfs_mntpoint, all snapshots of root dataset are mounted correctly
and become accessible.
This fix will come into play only if current process, that is trying to
access the snapshots is not in chroot context. The Linux kernel API
that is used to convert struct path into char format (d_path), returns
the complete path for given struct path. It works in chroot environment
as well and returns the correct path from original filesystem root.
However d_path fails to return the complete path if any directory from
original root filesystem is mounted using --bind flag or --rbind flag
in chroot environment. In this case, if we try to access the snapshot
from outside the chroot environment, d_path returns the path correctly,
i.e. it returns the correct path to the directory that is mounted with
--bind flag. However inside the chroot environment, it only returns the
path inside chroot.
For now, there is not a better way in my understanding that gives the
complete path in char format and handles the case where directories from
root filesystem are mounted with --bind or --rbind on another path which
user will later chroot into. So this fix gets enabled if current
process trying to access the snapshot is not in chroot context.
With the snapshots issue fixed for root filesystem, using mount.zfs in
ZFS initrd script, mounts the datasets with correct mount options.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes#16646
This fixes an oversight in the Direct I/O PR. There is nothing that
stops a process from manipulating the contents of a buffer for a
Direct I/O read while the I/O is in flight. This can lead checksum
verify failures. However, the disk contents are still correct, and this
would lead to false reporting of checksum validation failures.
To remedy this, all Direct I/O reads that have a checksum verification
failure are treated as suspicious. In the event a checksum validation
failure occurs for a Direct I/O read, then the I/O request will be
reissued though the ARC. This allows for actual validation to happen and
removes any possibility of the buffer being manipulated after the I/O
has been issued.
Just as with Direct I/O write checksum validation failures, Direct I/O
read checksum validation failures are reported though zpool status -d in
the DIO column. Also the zevent has been updated to have both:
1. dio_verify_wr -> Checksum verification failure for writes
2. dio_verify_rd -> Checksum verification failure for reads.
This allows for determining what I/O operation was the culprit for the
checksum verification failure. All DIO errors are reported only on the
top-level VDEV.
Even though FreeBSD can write protect pages (stable pages) it still has
the same issue as Linux with Direct I/O reads.
This commit updates the following:
1. Propogates checksum failures for reads all the way up to the
top-level VDEV.
2. Reports errors through zpool status -d as DIO.
3. Has two zevents for checksum verify errors with Direct I/O. One for
read and one for write.
4. Updates FreeBSD ABD code to also check for ABD_FLAG_FROM_PAGES and
handle ABD buffer contents validation the same as Linux.
5. Updated manipulate_user_buffer.c to also manipulate a buffer while a
Direct I/O read is taking place.
6. Adds a new ZTS test case dio_read_verify that stress tests the new
code.
7. Updated man pages.
8. Added an IMPLY statement to zio_checksum_verify() to make sure that
Direct I/O reads are not issued as speculative.
9. Removed self healing through mirror, raidz, and dRAID VDEVs for
Direct I/O reads.
This issue was first observed when installing a Windows 11 VM on a ZFS
dataset with the dataset property direct set to always. The zpool
devices would report checksum failures, but running a subsequent zpool
scrub would not repair any data and report no errors.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#16598
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
