We always call it twice with JUSTLOOKING and then FORREAL.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pawel Jakub Dawidek <pawel@dawidek.net>
Closes#16225
And, make the output fd an arg to zfs_dbgmsg_print(). This is a change
in behaviour, but keeps it consistent with where crash traces go, and
it's easy to argue this is what we want anyway; this is information
about the task, not the actual output of the task.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16181
FreeBSD was using fprintf(), which might not be signal-safe. Meanwhile,
Linux's locking did not cover the header output. This two quirks are
unrelated, but both have the same response: be like the other one. So
with this commit, both functions are the same except for the names of
their lock and list variables.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16181
When running a debug kernel with lockdep enabled there
are several locks which report false positives. Set
MUTEX_NOLOCKDEP/RW_NOLOCKDEP to disable these warnings.
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#16188
In P2ALIGN, the result would be incorrect when align is unsigned
integer and x is larger than max value of the type of align.
In that case, -(align) would be a positive integer, which means
high bits would be zero and finally stay zero after '&' when
align is converted to a larger integer type.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Youzhong Yang <yyang@mathworks.com>
Signed-off-by: Qiuhao Chen <chenqiuhao1997@gmail.com>
Closes#15940
This commit replaces current usages of schedule_timeout() with
schedule_timeout_interruptible() in code paths that expect the running
task to sleep for a short period of time. When schedule_timeout() is
called without previously calling set_current_state(), the running
task never sleeps because the task state remains in TASK_RUNNING.
By calling schedule_timeout_interruptible() to set the task state to
TASK_INTERRUPTIBLE before calling schedule_timeout() we achieve the
intended/desired behavior of putting the task to sleep for the
specified timeout.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Daniel Perry <dtperry@amazon.com>
Closes#16150
If the underlying device doesn't have a write-back cache, the kernel
will just return a successful response. This doesn't hurt anything, but
it's extra work on the IO taskqs that are unnecessary. So, detect this
when we open the device for the first time.
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#16148
When renaming a zvol, insert it into zvol_htable using the new name, not
the old name. Otherwise some operations won't work. For example,
"zfs set volsize" while the zvol is open.
Sponsored by: Axcient
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alek Pinchuk <apinchuk@axcient.com>
Signed-off-by: Alan Somers <asomers@FreeBSD.org>
Closes#16127Closes#16128
Previously, abd_iter_page() would assume that every scatterlist would
contain a single page (compound or no), because that's all we ever
create in abd_alloc_chunks(). However, scatterlists can contain multiple
pages of arbitrary provenance, and if we get one of those, we'd get all
the math wrong.
This reworks things to handle multiple pages in a scatterlist, by
properly finding the right page within it for the given offset, and
understanding better where the end of the page is and not crossing it.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reported-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16108
The only possible ioctl is a flush, and any other kind of meta-operation
introduced in the future is likely to have different semantics (much
like trim did). So, lets just call it what it is.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16064
There's no other options, so we can just always assume its a flush.
Includes some light refactoring where a switch statement was doing
control flow that no longer works.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16064
If a linear buffer spans multiple pages, and the first page has a
non-zero starting offset, the checker would not include the offset, and
so would think there was an alignment gap at the end of the first page,
rather than at the start.
That is, for a 16K buffer spread across five pages with an initial 512B
offset:
[.XXXXXXX][XXXXXXXX][XXXXXXXX][XXXXXXXX][XXXXXXX.]
It would be interpreted as:
[XXXXXXX.][XXXXXXXX]...
And be rejected as misaligned.
Since it's already a linear ABD, the "linearising" copy would just reuse
the buffer as-is, and the second check would failing, tripping the
VERIFY in vdev_disk_io_rw().
This commit fixes all this by including the offset in the check for
end-of-page alignment.
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#16076
This provides a test driver and a set of test vectors for the page
alignment check callback function vdev_disk_check_pages_cb().
Because there's no good facility for exposing this function to a
userspace test right now, for now I'm just duplicating the function and
adding commentary to remind people to keep them in sync.
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#16076
After 06e25f9c4, the discard issuing code was organised such that if
requesting an async discard or secure erase failed before the IO was
issued (that is, calling __blkdev_issue_discard() returned an error),
the failed zio would never be executed, resulting in txg_sync hanging
forever waiting for IO to finish.
This commit fixes that by immediately executing a failed zio on error.
To handle the successful synchronous op case, we fake an async op by,
when not using an asynchronous submission method, queuing the successful
result zio as part of the discard handler.
Since it was hard to understand the differences between discard and
secure erase, and sync and async, across different kernel versions, I've
commented and reorganised the code a bit to try and make everything more
contained and linear.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Ameer Hamza <ahamza@ixsystems.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#16070
99741bde5 accesses a cached blk-mq hardware context through the mq_hctx
field of struct request. However, this field did not exist until 5.0.
Before that, the private function blk_mq_map_queue() was used to dig it
out of broader queue context. This commit detects this situation, and
handles it with a poor-man's simulation of that function.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Ameer Hamza <ahamza@ixsystems.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#16069
99741bde5 introduced zvol_num_taskqs, but put it behind the HAVE_BLK_MQ
define, preventing builds on versions of Linux that don't have it
(<3.13, incl EL7).
Nothing about it seems dependent on blk-mq, so this just moves it out
from behind that define and so fixes the build.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Ameer Hamza <ahamza@ixsystems.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#16062
Currently, zvol uses a single taskq, resulting in throughput bottleneck
under heavy load due to lock contention on the single taskq. This patch
addresses the performance bottleneck under heavy load conditions by
utilizing multiple taskqs, thus mitigating lock contention. The number
of taskqs scale dynamically based on the available CPUs in the system,
as illustrated below:
taskq total
cpus taskqs threads threads
------- ------- ------- -------
1 1 32 32
2 1 32 32
4 1 32 32
8 2 16 32
16 3 11 33
32 5 7 35
64 8 8 64
128 11 12 132
256 16 16 256
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#15992
There's an extra nullable arg for queue limits. Detect it, and set it to
NULL. Similar change for blk_mq_alloc_disk(), now three args, same
treatment.
Error return now has error encoded in the return, so detect with
IS_ERR() and explicitly NULL our own return.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16027Closes#16033
bdev_open_by_path() is replaced by bdev_file_open_by_path(), which
returns a plain old struct file*. Release function is gone entirely; the
regular file release function fput() will take care of the bdev
specifics.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16027Closes#16033
After IO is unplugged, it may complete immediately and vbio_completion
be called on interrupt context. That may interrupt or deschedule our
task. If its the last bio, the vbio will be freed. Then, we get
rescheduled, and try to write to freed memory through vbio->.
This patch just removes the the cleanup, and the corresponding assert.
These were leftovers from a previous iteration of vbio_submit() and were
always "belt and suspenders" ops anyway, never strictly required.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc
Reported-by: Rich Ercolani <rincebrain@gmail.com>
Reviewed-by: Laurențiu Nicola <lnicola@dend.ro>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16045Closes#16050Closes#16049
#16047 notes that include/os/freebsd/spl/rpc/xdr.h carried an
(apparently) incompatible license. While looking into it, it seems that
this file is actually unnecessary these days - FreeBSD's kernel XDR has
XDR_CONTROL, xdrmem_control and XDR_GET_BYTES_AVAIL, while userspace has
XDR_CONTROL and xdrmem_control, and our implementation of
XDR_GET_BYTES_AVAIL for libspl works nicely with it. So this removes
that file outright.
To keep the includes in nvpair.c tidy, I've made a few small adjustments
to the Linux headers. By definition, rpc/types.h provides bool_t and is
included before rpc/xdr.h, so I've created rpc/types.h for Linux. This
isn't necessary for userspace; both FreeBSD native and tirpc on Linux
already have these headers set up correctly.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#16047Closes#16051
After IO is unplugged, it may complete immediately and vbio_completion
be called on interrupt context. That may interrupt or deschedule our
task. If its the last bio, the vbio will be freed. Then, we get
rescheduled, and try to write to freed memory through vbio->.
This patch just removes the the cleanup, and the corresponding assert.
These were leftovers from a previous iteration of vbio_submit() and were
always "belt and suspenders" ops anyway, never strictly required.
Reported-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes: #16045Closes: #16050
43e8f6e37 introduced a subtle API misuse, in that it passed the output
from vdev_bdev_mode() back into itself. Fortunately, the
SPA_MODE_(READ|WRITE) bit values exactly map to the FMODE_(READ|WRITE) &
BLK_OPEN_(READ|WRITE) bit values, so it didn't result in a bug, but it
was hard to read and understand, so I cleaned it up.
In doing so, I noticed that the only call to vdev_bdev_mode() without
the "exclusive" flag set was in that misuse, and actually, we never do a
non-exclusive blkdev_get_by_path(). So I've just made exclusive be
always-on.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#15995
currently, the linux kernel allows 2^20 minor devices per major device
number. ZFS reserves blocks of 2^4 minors per zvol: 1 for the zvol
itself, the other 15 for the first partitions of that zvol. as a result,
only 2^16 such blocks are available for use.
there are no checks in place to avoid overflowing into the major device
number when more than 2^16 zvols are allocated (with volmode=dev or
default). instead of ignoring this limit, which comes with all sorts of
weird knock-on effects, detect this situation and simply fail allocating
the zvol block device early on.
without this safeguard, the kernel will reject the attempt to create an
already existing block device, but ZFS doesn't handle this error and
gets confused about which zvol occupies which minor slot, potentially
resulting in kernel NULL derefs and other issues later on.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Closes#16006
Before 4.5 (specifically, torvalds/linux@ddc58f2), head and tail pages
in a compound page were refcounted separately. This means that using the
head page without taking a reference to it could see it cleaned up later
before we're finished with it. Specifically, bio_add_page() would take a
reference, and drop its reference after the bio completion callback
returns.
If the zio is executed immediately from the completion callback, this is
usually ok, as any data is referenced through the tail page referenced
by the ABD, and so becomes "live" that way. If there's a delay in zio
execution (high load, error injection), then the head page can be freed,
along with any dirty flags or other indicators that the underlying
memory is used. Later, when the zio completes and that memory is
accessed, its either unmapped and an unhandled fault takes down the
entire system, or it is mapped and we end up messing around in someone
else's memory. Both of these are very bad.
The solution on these older kernels is to take a reference to the head
page when we use it, and release it when we're done. There's not really
a sensible way under our current structure to do this; the "best" would
be to keep a list of head page references in the ABD, and release them
when the ABD is freed.
Since this additional overhead is totally unnecessary on 4.5+, where
head and tail pages share refcounts, I've opted to simply not use the
compound head in ABD page iteration there. This is theoretically less
efficient (though cleaning up head page references would add overhead),
but its safe, and we still get the other benefits of not mapping pages
before adding them to a bio and not mis-splitting pages.
There doesn't appear to be an obvious symbol name or config option we
can match on to discover this behaviour in configure (and the mm/page
APIs have changed a lot since then anyway), so I've gone with a simple
version check.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#15533Closes#15588
Simplifies our code a lot, so we don't have to wait for each and
reassemble them.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#15533Closes#15588
This makes the submission method selectable at module load time via the
`zfs_vdev_disk_classic` parameter, allowing this change to be backported
to 2.2 safely, and disabled in favour of the "classic" submission method
if new problems come up.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#15533Closes#15588
This commit tackles a number of issues in the way BIOs (`struct bio`)
are constructed for submission to the Linux block layer.
The kernel has a hard upper limit on the number of pages/segments that
can be added to a BIO, as well as a separate limit for each device
(related to its queue depth and other scheduling characteristics).
ZFS counts the number of memory pages in the request ABD
(`abd_nr_pages_off()`, and then uses that as the number of segments to
put into the BIO, up to the hard upper limit. If it requires more than
the limit, it will create multiple BIOs.
Leaving aside the fact that page count method is wrong (see below), not
limiting to the device segment max means that the device driver will
need to split the BIO in half. This is alone is not necessarily a
problem, but it interacts with another issue to cause a much larger
problem.
The kernel function to add a segment to a BIO (`bio_add_page()`) takes a
`struct page` pointer, and offset+len within it. `struct page` can
represent a run of contiguous memory pages (known as a "compound page").
In can be of arbitrary length.
The ZFS functions that count ABD pages and load them into the BIO
(`abd_nr_pages_off()`, `bio_map()` and `abd_bio_map_off()`) will never
consider a page to be more than `PAGE_SIZE` (4K), even if the `struct
page` is for multiple pages. In this case, it will load the same `struct
page` into the BIO multiple times, with the offset adjusted each time.
With a sufficiently large ABD, this can easily lead to the BIO being
entirely filled much earlier than it could have been. This is also
further contributes to the problem caused by the incorrect segment limit
calculation, as its much easier to go past the device limit, and so
require a split.
Again, this is not a problem on its own.
The logic for "never submit more than `PAGE_SIZE`" is actually a little
more subtle. It will actually never submit a buffer that crosses a 4K
page boundary.
In practice, this is fine, as most ABDs are scattered, that is a list of
complete 4K pages, and so are loaded in as such.
Linear ABDs are typically allocated from slabs, and for small sizes they
are frequently not aligned to page boundaries. For example, a 12K
allocation can span four pages, eg:
-- 4K -- -- 4K -- -- 4K -- -- 4K --
| | | | |
:## ######## ######## ######: [1K, 4K, 4K, 3K]
Such an allocation would be loaded into a BIO as you see:
[1K, 4K, 4K, 3K]
This tends not to be a problem in practice, because even if the BIO were
filled and needed to be split, each half would still have either a start
or end aligned to the logical block size of the device (assuming 4K at
least).
---
In ideal circumstances, these shortcomings don't cause any particular
problems. Its when they start to interact with other ZFS features that
things get interesting.
Aggregation will create a "gang" ABD, which is simply a list of other
ABDs. Iterating over a gang ABD is just iterating over each ABD within
it in turn.
Because the segments are simply loaded in order, we can end up with
uneven segments either side of the "gap" between the two ABDs. For
example, two 12K ABDs might be aggregated and then loaded as:
[1K, 4K, 4K, 3K, 2K, 4K, 4K, 2K]
Should a split occur, each individual BIO can end up either having an
start or end offset that is not aligned to the logical block size, which
some drivers (eg SCSI) will reject. However, this tends not to happen
because the default aggregation limit usually keeps the BIO small enough
to not require more than one split, and most pages are actually full 4K
pages, so hitting an uneven gap is very rare anyway.
If the pool is under particular memory pressure, then an IO can be
broken down into a "gang block", a 512-byte block composed of a header
and up to three block pointers. Each points to a fragment of the
original write, or in turn, another gang block, breaking the original
data up over and over until space can be found in the pool for each of
them.
Each gang header is a separate 512-byte memory allocation from a slab,
that needs to be written down to disk. When the gang header is added to
the BIO, its a single 512-byte segment.
Pulling all this together, consider a large aggregated write of gang
blocks. This results a BIO containing lots of 512-byte segments. Given
our tendency to overfill the BIO, a split is likely, and most possible
split points will yield a pair of BIOs that are misaligned. Drivers that
care, like the SCSI driver, will reject them.
---
This commit is a substantial refactor and rewrite of much of `vdev_disk`
to sort all this out.
`vdev_bio_max_segs()` now returns the ideal maximum size for the device,
if available. There's also a tuneable `zfs_vdev_disk_max_segs` to
override this, to assist with testing.
We scan the ABD up front to count the number of pages within it, and to
confirm that if we submitted all those pages to one or more BIOs, it
could be split at any point with creating a misaligned BIO. If the
pages in the BIO are not usable (as in any of the above situations), the
ABD is linearised, and then checked again. This is the same technique
used in `vdev_geom` on FreeBSD, adjusted for Linux's variable page size
and allocator quirks.
`vbio_t` is a cleanup and enhancement of the old `dio_request_t`. The
idea is simply that it can hold all the state needed to create, submit
and return multiple BIOs, including all the refcounts, the ABD copy if
it was needed, and so on. Apart from what I hope is a clearer interface,
the major difference is that because we know how many BIOs we'll need up
front, we don't need the old overflow logic that would grow the BIO
array, throw away all the old work and restart. We can get it right from
the start.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#15533Closes#15588
This is just setting up for the next couple of commits, which will add a
new IO function and a parameter to select it.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#15533Closes#15588
Light reshuffle to make it a bit more linear to read and get rid of a
bunch of args that aren't needed in all cases.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#15533Closes#15588
This is just renaming the existing functions we're about to replace and
grouping them together to make the next commits easier to follow.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#15533Closes#15588
The regular ABD iterators yield data buffers, so they have to map and
unmap pages into kernel memory. If the caller only wants to count
chunks, or can use page pointers directly, then the map/unmap is just
unnecessary overhead.
This adds adb_iterate_page_func, which yields unmapped struct page
instead.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#15533Closes#15588
1) Make mmap flushes synchronous. Linux may skip flushing dirty pages
already in writeback unless data-integrity sync is requested.
2) Change zfs_putpage to use TXG_WAIT. Otherwise dirty pages may be
skipped due to DMU pushing back on TX assign.
3) Add missing mmap flush when doing block cloning.
4) While here, pass errors from putpage to writepage/writepages.
This change fixes corruption edge cases, but unfortunately adds
synchronous ZIL flushes for dirty mmap pages to llseek and bclone
operations. It may be possible to avoid these sync writes later
but would need more tricky refactoring of the writeback code.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Robert Evans <evansr@google.com>
Closes#15933Closes#16019
Linux 6.8 removes generic_copy_file_range(), which had been reduced to a
simple wrapper around splice_copy_file_range(). Detect that function
directly and use it if generic_ is not available.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#15930Closes#15931
This commit fixes a bug whereby owner@ ACL that limits WRITE_DATA
access for the owner of a file was not being properly enforced. The
owner of a file should be prevented from write access in this case,
but being owner of file should still allow the file owner to chmod,
chown, and setacl.
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
This function can be frequently called with MAY_EXEC|MAY_NOT_BLOCK
during RCU path walk. Where possible we should try not to break
out of it. In this case we check whether flag ZFS_NO_EXECS_DENIED is
set and check mode (similar to fastexecute check in zfs_acl.c).
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
This removes an extra memory allocation / free from the
NFS4 ACL xattr handler. Initially this was written rather
quickly in the alpha cycle of SCALE and implemented in a
way to ensure that xattr was exactly matching format
used internally in samba's vfs_acl_xattr module. Since
this time a more efficient conversion between the Samba
format and various other ones was added for the purpose
of inclusion in the Kernel NFS server.
This change simplifies conversion between internal NFS ACL and
external xattr representation, but has no impact on userspace
and kernel consumers of this xattr (format does not change).
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
MS-FSCC 2.6 is the governing document for
DOS attribute behavior. It specifies the following:
For a file, applications can read the file but
cannot write to it or delete it. For a directory,
applications cannot delete it, but applications can
create and delete files from the directory.
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
When a new file is created on FreeBSD it is given the group
of the directory which contains it. On Linux it is given
to either the effective GID of the process (System V semantices)
or the GID of the parent directory (BSD semantics).
Since there is no hard-and-fast rule about creation semantics
for NFSv4 ACLs on Linux, we should opt for what is least likely
to break users permissions on change from FreeBSD to Linux.
Avoid setting actually setting the SGID bit on dirs unless
it was explicitly set.
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
On Linux POSIX ACLs can be removed via rmxattr() for the
relevant system xattrs. On FreeBSD a non-trivial ACL
can be converted to one that is described by the mode with
no loss of info via combination of acl_get_file(), acl_strip_np(),
and acl_set_file(). Since there's no libc equivalent of these
ops in Linux for NFSv4 ACLs, this commit makes this less error
prone by handling entirely in ZFS. When user performs
rmxattr() vfs_setxattr() is called with value of NULL and length
of 0. Add special handling for this situation in the xattr
handler for the NFSv4 ACL so that we generate a new ACL and
zfs_acl_chmod() with the existing mode of file, then set the ACL.
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
Add ACL_IS_TRIVIAL and ACL_IS_DIR flags as ACL-wide flags
in the system.nfs4_acl_xdr generated on getxattr requests.
This are non-RFC flags that are useful for userspace applications
(especially the ACL_IS_TRIVIAL flag as it can be used to avoid
relatively expensive ACL-related operations).
Also add system.nfs4_acl_xdr to xattr results if ACL is not trivial.
This duplicates POSIX ACL behavior where whether an ACL is
set on a path can be determined via listxattr(). Since the ACL
is not actually removed, we check whether the ZFS_ACL_TRIVIAL
is set. If the flag is not set, then we omit the xattr name from
the list. This allows users to determine whether ACL is trivial from
listxattr().
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
The "permission" inode operation takes a new `struct user_namespace *`
parameter starting in Linux 5.12.
Add a configure check and adapt accordingly.
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Properly evaluate edge cases where user credential may grant capability
to override DAC in various situations. Switch to using ns-aware checks
rather than capable().
Expand optimization allow bypass of zfs_zaccess() in case of trivial
ACL if MAY_OPEN is included in requested mask. This will be evaluated
in generic_permission() check, which is RCU walk safe. This means that
in most cases evaluating permissions on boot volume with NFSv4 ACLs
will follow the fast path on checking inode permissions.
Additionally, CAP_SYS_ADMIN is granted to nfsd process, and so override
for this capability in access2 policy check is removed in favor of a
simple check for fsid == 0. Checks for CAP_DAC_OVERRIDE and other
override capabilities are kept as-is.
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
This implements NFSv41 (RFC 5661) ACLs in a manner
compatible with vfs_nfs4acl_xattr in Samba and
nfs4xdr-acl-tools.
There are three key areas of change in this commit:
1) NFSv4 ACL management through system.nfs4_acl_xdr xattr.
Install an xattr handler for "system.nfs4_acl_xdr" that
presents an xattr containing full NFSv41 ACL structures
generated through rpcgen using specification from the Samba
project. This xattr is used by userspace programs to read and
set permissions.
2) add an i_op->permissions endpoint: zpl_permissions(). This
is used by the VFS in Linux to determine whether to allow /
deny an operation. Wherever possible, we try to avoid having
to call zfs_access(). If kernel has NFSv4 patch for VFS, then
perform more complete check of avaiable access mask.
3) add capability-based overrides to secpolicy_vnode_access2()
there are various situations in which ACL may need to be
overridden based on capabilities. This logic is almost directly
copied from Linux VFS. For instance, root needs to be able to
always read / write ACLs (otherwise admin can get locked out
from files).
This is commit was initially inspired by work from Paul B. Henson
to implement NFSv4.0 (RFC3530) ACLs in ZFS on Linux. Key areas of
divergence are as follows:
- ACL specification, xattr format, xattr name
- Addition of handling for NFSv4 masks from Linux VFS
- Addition of ACL overrides based on capabilities
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
Ameer Hamza
Pawel Jakub Dawidek
Rob Norris
Brian Behlendorf
chenqiuhao1997
Daniel Perry
Rob N
Alan Somers
Fabian-Gruenbichler
Robert Evans
Andrew Walker
Ryan Moeller