In a4b21eadec we added the zap_micro_max_size tuneable to raise the size
at which "micro" (single-block) ZAPs are upgraded to "fat" (multi-block)
ZAPs. Before this, a microZAP was limited to 128KiB, which was the old
largest block size. The side effect of raising the max size past 128KiB
is that it be stored in a large block, requiring the large_blocks
feature.
Unfortunately, this means that a backup stream created without the
--large-block (-L) flag to zfs send would split the microZAP block into
smaller blocks and send those, as is normal behaviour for large blocks.
This would be received correctly, but since microZAPs are limited to the
first block in the object by definition, the entries in the later blocks
would be inaccessible. For directory ZAPs, this gives the appearance of
files being lost.
This commit adds a feature flag, large_microzap, that must be enabled
for microZAPs to grow beyond 128KiB, and which will be activated the
first time that occurs. This feature is later checked when generating
the stream and if active, the send operation will abort unless
--large-block has also been requested.
Changing the limit still requires zap_micro_max_size to be changed. The
state of this flag effectively sets the upper value for this tuneable,
that is, if the feature is disabled, the tuneable will be clamped to
128KiB.
A stream flag is also added to ensure that the receiver also activates
its own feature flag upon receiving the stream. This is not strictly
necessary to _use_ the received microZAP, since it doesn't care how
large its block is, but it is required to send the microZAP object on,
otherwise the original problem occurs again.
Because it's difficult to reliably distinguish a microZAP from a fatZAP
from outside the ZAP code, and because it seems unlikely that most
users are affected (a fairly niche tuneable combined with what should be
an uncommon use of send), and for the sake of expediency, this change
activates the feature the first time a microZAP grows to use a large
block, and is never deactivated after that. This can be improved in the
future.
This commit changes nothing for existing pools that already have large
microZAPs. The feature will not be retroactively applied, but will be
activated the next time a microZAP grows past the limit.
Don't use large_blocks feature for enable/disable tests. The
large_microzap depends on large_blocks, so it gets enabled as a
dependency, breaking the test. Instead use feature "longname", which has
the exact same feature characteristics.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16593
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
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 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
The docs for drr_versioninfo have marked the top 32 bits as "reserved"
since its introduction (illumos/illumos-gate@9e69d7d). There's no
indication of why they're reserved, so it seems uncontroversial to make
a lot more flags available.
I'm keeping the top eight reserved, and explicitly calling them out as
such, so we can extend the header further in the future if we run out of
flags or want to do some kind of change that isn't about feature flags.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#15454
ZIL log record structs (lr_XX_t) are frequently allocated with extra
space after the struct to carry variable-sized "payload" items.
Linux 6.10+ compiled with CONFIG_FORTIFY_SOURCE has been doing runtime
bounds checking on memcpy() calls. Because these types had no indicator
that they might use more space than their simple definition,
__fortify_memcpy_chk will frequently complain about overruns eg:
memcpy: detected field-spanning write (size 7) of single field
"lr + 1" at zfs_log.c:425 (size 0)
memcpy: detected field-spanning write (size 9) of single field
"(char *)(lr + 1)" at zfs_log.c:593 (size 0)
memcpy: detected field-spanning write (size 4) of single field
"(char *)(lr + 1) + snamesize" at zfs_log.c:594 (size 0)
memcpy: detected field-spanning write (size 7) of single field
"lr + 1" at zfs_log.c:425 (size 0)
memcpy: detected field-spanning write (size 9) of single field
"(char *)(lr + 1)" at zfs_log.c:593 (size 0)
memcpy: detected field-spanning write (size 4) of single field
"(char *)(lr + 1) + snamesize" at zfs_log.c:594 (size 0)
memcpy: detected field-spanning write (size 7) of single field
"lr + 1" at zfs_log.c:425 (size 0)
memcpy: detected field-spanning write (size 9) of single field
"(char *)(lr + 1)" at zfs_log.c:593 (size 0)
memcpy: detected field-spanning write (size 4) of single field
"(char *)(lr + 1) + snamesize" at zfs_log.c:594 (size 0)
To fix this, this commit adds flex array fields to all lr_XX_t structs
that require them, and then uses those fields to access that
end-of-struct area rather than more complicated casts and pointer
addition.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#16501Closes#16539
Too many times, people's performance problems have amounted to
"somehow your SIMD support isn't working", and determining that
at runtime is difficult to describe to people.
This adds a /proc/spl/kstat/zfs/simd node, which exposes
metadata about which instructions ZFS thinks it can use,
on AArch64 and x86_64 Linux, to make investigating things
like this much easier.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#16530
ZLE compressor needs additional bytes to process
d_len argument efficiently.
Don't use BPE_PAYLOAD_SIZE as d_len with it
before we rework zle compressor somehow.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes#9416
Now default compression is lz4, which can stop
compression process by itself on incompressible data.
If there are additional size checks -
we will only make our compressratio worse.
New usable compression thresholds are:
- less than BPE_PAYLOAD_SIZE (embedded_data feature);
- at least one saved sector.
Old 12.5% threshold is left to minimize affect
on existing user expectations of CPU utilization.
If data wasn't compressed - it will be saved as
ZIO_COMPRESS_OFF, so if we really need to recompress
data without ashift info and check anything -
we can just compress it with zero threshold.
So, we don't need a new feature flag here!
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes#9416
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
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
Specializing cityhash4 on 32-bit architectures can reduce the size
of stack frames as well as instruction count. This is a tiny but
useful optimization, since some callers invoke it frequently.
When specializing into 1/2/3/4-arg versions, the stack usage
(in bytes) on some 32-bit arches are listed as follows:
- x86: 32, 32, 32, 40
- arm-v7a: 20, 20, 28, 36
- riscv: 0, 0, 0, 16
- power: 16, 16, 16, 32
- mipsel: 8, 8, 8, 24
And each actual argument (even if passing 0) contributes evenly
to the number of multiplication instructions generated:
- x86: 9, 12, 15 ,18
- arm-v7a: 6, 8, 10, 12
- riscv / power: 12, 18, 20, 24
- mipsel: 9, 12, 15, 19
On 64-bit architectures, the tendencies are similar. But both stack
sizes and instruction counts are significantly smaller thus negligible.
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
