1. When testing out installing a VM with virtual manager on Linux and a
dataset with direct=always, there an ASSERT failure in
abd_alloc_from_pages(). Originally zfs_setup_direct() did an
alignment check of the UIO using SPA_MINBLOCKSIZE with
zfs_uio_aligned(). The idea behind this was maybe the page alignment
restriction could be changed to use ashift as the alignment check in
the future. Howver, this diea never came to be. The alignment
restrictions for Direct I/O are based on PAGE_SIZE. Updating the
check zfs_setup_direct() for the UIO to use PAGE_SIZE fixed the
issue.
2. Updated other alignment check in dmu_read_impl() to also use
PAGE_SIZE.
3. As a consequence of updating the UIO alignment checks the ZTS test
case dio_unaligned_filesize began to fail. This is because there was
no way to detect reading past the end of the file before issue EINVAL
in the ZPL and VOPs layers in FreeBSD. This was resolved by moving
zfs_setup_direct() into zfs_write() and zfs_read(). This allows for
other error checking to take place before checking any Direct I/O
limitations. Updating the call site of zfs_setup_direct() did require
a bit of changes to the logic in that function. In particular Direct
I/O can just be avoid altogether depending on the checks in
zfs_setup_direct() and there is no reason to return EAGAIN at all.
4. After moving zfs_setup_direct() into zfs_write() and zfs_read(),
there was no reason to call zfs_check_direct_enabled() in the ZPL
layer in Linux or in the VNOPS layer of FreeBSD. This function was
completely removed. This allowed for much of the code in both those
layers to return to their original code.
5. Upated the checksum verify module parameter for Direct I/O writes to
only be a boolean and return EIO in the event a checksum verify
failure occurs. By default, this module parameter is set to 1 for
Linux and 0 for FreeBSD. The module parameter has been changed to
zfs_vdev_direct_write_verify. There are still counters on the
top-level VDEV for checksum verify failures, but this could be
removed. It would still be good to to leave the ZED event dio_verify
for checksum failures as a notification that an application was
manipulating the contents of a buffer after issuing that buffer with
for I/O using Direct I/O. As part of this cahnge, man pages were
updated, the ZTS test case dio_writy_verify was updated, and all
comments relating to the module parameter were udpated as well.
6. Updated comments in dio_property ZTS test to properly reflect that
stride_dd is being called with check_write and check_read.
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Adding O_DIRECT support to ZFS to bypass the ARC for writes/reads.
O_DIRECT support in ZFS will always ensure there is coherency between
buffered and O_DIRECT IO requests. This ensures that all IO requests,
whether buffered or direct, will see the same file contents at all
times. Just as in other FS's , O_DIRECT does not imply O_SYNC. While
data is written directly to VDEV disks, metadata will not be synced
until the associated TXG is synced.
For both O_DIRECT read and write request the offset and requeset sizes,
at a minimum, must be PAGE_SIZE aligned. In the event they are not,
then EINVAL is returned unless the direct property is set to always (see
below).
For O_DIRECT writes:
The request also must be block aligned (recordsize) or the write
request will take the normal (buffered) write path. In the event that
request is block aligned and a cached copy of the buffer in the ARC,
then it will be discarded from the ARC forcing all further reads to
retrieve the data from disk.
For O_DIRECT reads:
The only alignment restrictions are PAGE_SIZE alignment. In the event
that the requested data is in buffered (in the ARC) it will just be
copied from the ARC into the user buffer.
For both O_DIRECT writes and reads the O_DIRECT flag will be ignored in
the event that file contents are mmap'ed. In this case, all requests
that are at least PAGE_SIZE aligned will just fall back to the buffered
paths. If the request however is not PAGE_SIZE aligned, EINVAL will
be returned as always regardless if the file's contents are mmap'ed.
Since O_DIRECT writes go through the normal ZIO pipeline, the
following operations are supported just as with normal buffered writes:
Checksum
Compression
Dedup
Encryption
Erasure Coding
There is one caveat for the data integrity of O_DIRECT writes that is
distinct for each of the OS's supported by ZFS.
FreeBSD - FreeBSD is able to place user pages under write protection so
any data in the user buffers and written directly down to the
VDEV disks is guaranteed to not change. There is no concern
with data integrity and O_DIRECT writes.
Linux - Linux is not able to place anonymous user pages under write
protection. Because of this, if the user decides to manipulate
the page contents while the write operation is occurring, data
integrity can not be guaranteed. However, there is a module
parameter `zfs_vdev_direct_write_verify` that contols the
if a O_DIRECT writes that can occur to a top-level VDEV before
a checksum verify is run before the contents of the I/O buffer
are committed to disk. In the event of a checksum verification
failure the write will return EIO. The number of O_DIRECT write
checksum verification errors can be observed by doing
`zpool status -d`, which will list all verification errors that
have occurred on a top-level VDEV. Along with `zpool status`, a
ZED event will be issues as `dio_verify` when a checksum
verification error occurs.
A new dataset property `direct` has been added with the following 3
allowable values:
disabled - Accepts O_DIRECT flag, but silently ignores it and treats
the request as a buffered IO request.
standard - Follows the alignment restrictions outlined above for
write/read IO requests when the O_DIRECT flag is used.
always - Treats every write/read IO request as though it passed
O_DIRECT and will do O_DIRECT if the alignment restrictions
are met otherwise will redirect through the ARC. This
property will not allow a request to fail.
There is also a module paramter zfs_dio_enabled that can be used to
force all reads and writes through the ARC. By setting this module
paramter to 0, it mimics as if the direct dataset property is set to
disabled.
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Co-authored-by: Mark Maybee <mark.maybee@delphix.com>
Co-authored-by: Matt Macy <mmacy@FreeBSD.org>
Co-authored-by: Brian Behlendorf <behlendorf@llnl.gov>
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
Adds 'ioctl' as a valid IO type for device error injection, so we can
simulate a flush error (which OpenZFS currently ignores, but that's by
the by).
To support this, adding ZIO_STAGE_VDEV_IO_DONE to ZIO_IOCTL_PIPELINE,
since that's where device error injection happens. This needs a small
exclusion to avoid the vdev_queue, since flushes are not queued, and I'm
assuming that the various failure responses are still reasonable for
flush failures (probes, media change, etc). This seems reasonable to me,
as a flush failure is not unlike a write failure in this regard, however
this may be too aggressive or subtle to assume in just this change.
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#16061
- add column for TRIM ZIOs
- remove R from ZIO_STAGE_ISSUE_ASYNC, never happened
- remove I from ZIO_STAGE_VDEV_IO_DONE, never happened
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#15959
With anything but fletcher-4, even a tiny change in the input will cause
the checksum value to change completely. So knowing the actual and
expected checksums doesn't provide much more information than "they
don't match". The harm in sending them is simply that they bloat the
event. In particular, on FreeBSD the event must fit into a 1016 byte
buffer.
Fixes#14717 for mirrored pools.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Alan Somers <asomers@gmail.com>
Sponsored-by: Axcient
Closes#14717Closes#15052
The checksum histograms were intended to be used with ATA and parallel
SCSI, which are obsolete. With modern storage hardware, they will
almost always look like white noise; all bits will be wrong. They only
serve to bloat the event. That's a particular problem on FreeBSD, where
events must fit into a 1016 byte buffer.
This fixes issue #14717 for RAIDZ pools, but not for mirror pools.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Alan Somers <asomers@gmail.com>
Sponsored-by: Axcient
Closes#15052
It was a vdev level read cache, designed to aggregate many small
reads by speculatively issuing bigger reads instead and caching
the result. But since it has almost no idea about what is going
on with exception of ZIO_FLAG_DONT_CACHE flag set by higher layers,
it was found to make more harm than good, for which reason it was
disabled for the past 12 years. These days we have much better
instruments to enlarge the I/Os, such as speculative and prescient
prefetches, I/O scheduler, I/O aggregation etc.
Besides just the dead code removal this removes one extra mutex
lock/unlock per write inside vdev_cache_write(), not otherwise
disabled and trying to do some work.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#14953
And bump all the values after it, matching the header update in
67a1b037.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#14665
Correct new mandoc errors.
```
STYLE: input text line longer than 80 bytes
STYLE: no blank before trailing delimiter
```
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes#14148
Use proper names (i.e. zfs-allow and zpool-add) in NAME subsections
of zfs/zpool subcommands instead of current "pretty-printed" ones as
makewhatis utilities (or some implementations of it, namely the one
from mandoc suite used in FreeBSD) look not only at the document title
but also in NAME subsection, adding zfs(8)/zpool(8) to search results
which is not correct. (Common sense and other utilities splitting
subcommands in multiple man pages, e.g. git, do the same.)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: xtouqh <xtouqh@hotmail.com>
Closes#11086
The recommended practice for `.Os` on FreeBSD is to not specify any
arguments. The correct OS name is used automatically.
Oddly enough, on the Linux distro I tested this on (CentOS 7), the man
pager defaulted to displaying "BSD" as the OS rather than "Linux". To
accommodate this, tack " Linux" back on in an install hook on Linux.
This is much simpler than removing it for FreeBSD when vendored in the
base system.
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#10760
Moved subcommand topics into individual manpages. Reordered and
grouped the list of subcommands by topic.
Moved concepts overview to `zpoolconcepts.8` and the long list of
available pool properties to `zpoolprops.8`.
Internal cross-references copied from `zpool.8` needed to be
converted to `.Xr` external references to new subcommand manual
pages.
Move `autotrim` into lexical order, autotrim tacked onto the end
of a list. Now it is in alphabetical order.
Clarify attach/detach description. Description was too specific to
command syntax. Overview clarifies reason for attaching or detaching
a device.
Clarify replace description, don't refer to subcommand arguments.
Clarify split command description, say what split actually does and
why you'd want to do it.
Clarify description of upgrade, and simplify the zpool.8 wording of
the zpool-upgrade(8) description.
Clarify description of import, detail what zpool-import(8) actually
does.
Add appropriate SEE ALSO sections. Divided zpool subcommand manual
pages need their own SEE ALSO sections. Also modified fsck.zfs.8
to point directly to zfs-scrub.8 and zed.8.in to include a direct
reference to zfs-events.8
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ross Williams <ross@ross-williams.net>
Closes#9564
Brian Atkinson
Rob Norris
Alan Somers
Alexander Motin
Rob N
szubersk
Tino Reichardt
chrisrd
наб
xtouqh
Ryan Moeller
Ross Williams