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
On Linux, ZFS uses blkdev_issue_discard in vdev_disk_io_trim to issue
trim command which is synchronous.
This commit updates vdev_disk_io_trim to use __blkdev_issue_discard,
which is asynchronous. Unfortunately there isn't any asynchronous
version for blkdev_issue_secure_erase, so performance of secure trim
will still suffer.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes#15843
blkdev_get_by_path() and blkdev_put() have been replaced by
bdev_open_by_path() and bdev_release(), which return a "handle" object
with the bdev object itself inside.
This adds detection for the new functions, and macros to handle the old
and new forms consistently.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/Closes#15805
On some systems we already have blkdev_get_by_path() with 4 args
but still the old FMODE_EXCL and not BLK_OPEN_EXCL defined.
The vdev_bdev_mode() function was added to handle this case
but there was no generic way to specify exclusive access.
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#15692
Multiple changes to the blkdev API were introduced in Linux 6.5. This
includes passing (void* holder) to blkdev_put, adding a new
blk_holder_ops* arg to blkdev_get_by_path, adding a new blk_mode_t type
that replaces uses of fmode_t, and removing an argument from the release
handler on block_device_operations that we weren't using. The open
function definition has also changed to take gendisk* and blk_mode_t, so
update it accordingly, too.
Implement local wrappers for blkdev_get_by_path() and
vdev_blkdev_put() so that the in-line calls are cleaner, and place the
conditionally-compiled implementation details inside of both of these
local wrappers. Both calls are exclusively used within vdev_disk.c, at
this time.
Add blk_mode_is_open_write() to test FMODE_WRITE / BLK_OPEN_WRITE
The wrapper function is now used for testing using the appropriate
method for the kernel, whether the open mode is writable or not.
Emphasize fmode_t arg in zvol_release is not used
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#15099
I recently gained the ability to run Clang's static analyzer on the
linux kernel modules via a few hacks. This extended coverage to code
that was previously missed since Clang's static analyzer only looked at
code that we built in userspace. Running it against the Linux kernel
modules built from my local branch produced a total of 72 reports
against my local branch. Of those, 50 were reports of logic errors and
22 were reports of dead code. Since we already had cleaned up all of
the previous dead code reports, I felt it would be a good next step to
clean up these dead code reports. Clang did a further breakdown of the
dead code reports into:
Dead assignment 15
Dead increment 2
Dead nested assignment 5
The benefit of cleaning these up, especially in the case of dead nested
assignment, is that they can expose places where our error handling is
incorrect. A number of them were fairly straight forward. However
several were not:
In vdev_disk_physio_completion(), not only were we not using the return
value from the static function vdev_disk_dio_put(), but nothing used it,
so I changed it to return void and removed the existing (void) cast in
the other area where we call it in addition to no longer storing it to a
stack value.
In FSE_createDTable(), the function is dead code. Its helper function
FSE_freeDTable() is also dead code, as are the CPP definitions in
`module/zstd/include/zstd_compat_wrapper.h`. We just delete it all.
In zfs_zevent_wait(), we have an optimization opportunity. cv_wait_sig()
returns 0 if there are waiting signals and 1 if there are none. The
Linux SPL version literally returns `signal_pending(current) ? 0 : 1)`
and FreeBSD implements the same semantics, we can just do
`!cv_wait_sig()` in place of `signal_pending(current)` to avoid
unnecessarily calling it again.
zfs_setattr() on FreeBSD version did not have error handling issue
because the code was removed entirely from FreeBSD version. The error is
from updating the attribute directory's files. After some thought, I
decided to propapage errors on it to userspace.
In zfs_secpolicy_tmp_snapshot(), we ignore a lack of permission from the
first check in favor of checking three other permissions. I assume this
is intentional.
In zfs_create_fs(), the return value of zap_update() was not checked
despite setting an important version number. I see no backward
compatibility reason to permit failures, so we add an assertion to catch
failures. Interestingly, Linux is still using ASSERT(error == 0) from
OpenSolaris while FreeBSD has switched to the improved ASSERT0(error)
from illumos, although illumos has yet to adopt it here. ASSERT(error ==
0) was used on Linux while ASSERT0(error) was used on FreeBSD since the
entire file needs conversion and that should be the subject of
another patch.
dnode_move()'s issue was caused by us not having implemented
POINTER_IS_VALID() on Linux. We have a stub in
`include/os/linux/spl/sys/kmem_cache.h` for it, when it really should be
in `include/os/linux/spl/sys/kmem.h` to be consistent with
Illumos/OpenSolaris. FreeBSD put both `POINTER_IS_VALID()` and
`POINTER_INVALIDATE()` in `include/os/freebsd/spl/sys/kmem.h`, so we
copy what it did.
Whenever a report was in platform-specific code, I checked the FreeBSD
version to see if it also applied to FreeBSD, but it was only relevant a
few times.
Lastly, the patch that enabled Clang's static analyzer to be run on the
Linux kernel modules needs more work before it can be put into a PR. I
plan to do that in the future as part of the on-going static analysis
work that I am doing.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14380
The Linux 5.16.14 kernel's coccicheck caught this. The semantic
patch that caught it was:
./scripts/coccinelle/misc/flexible_array.cocci
The Linux kernel's documentation makes a good case for why we should not
use these:
https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14372
zio is never NULL when given to the vdev. Coverity complained saying:
"Either the check against null is unnecessary, or there may be a null
pointer dereference."
Reported-by: Coverity (CID-1466174)
Reviewed-by: Damian Szuberski <szuberskidamian@gmail.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14263
Linux defaults to setting "failfast" on BIOs, so that the OS will not
retry IOs that fail, and instead report the error to ZFS.
In some cases, such as errors reported by the HBA driver, not
the device itself, we would wish to retry rather than generating
vdev errors in ZFS. This new property allows that.
This introduces a per vdev option to disable the failfast option.
This also introduces a global module parameter to define the failfast
mask value.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Mariusz Zaborski <mariusz.zaborski@klarasystems.com>
Sponsored-by: Seagate Technology LLC
Submitted-by: Klara, Inc.
Closes#14056
Some of our customers have been occasionally hitting zfs import failures
in Linux because udevd doesn't create the by-id symbolic links in time
for zpool import to use them. The main issue is that the
systemd-udev-settle.service that zfs-import-cache.service and other
services depend on is racy. There is also an openzfs issue filed (see
https://github.com/openzfs/zfs/issues/10891) outlining the problem and
potential solutions.
With the proper solutions being significant in terms of complexity and
the priority of the issue being low for the time being, this patch
exposes `zfs_vdev_open_timeout_ms` as a tunable so people that are
experiencing this issue often can increase it as a workaround.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Don Brady <don.brady@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#14133
We ran out of space in enum zio_flag for additional flags. Rather than
introduce enum zio_flag2 and then modify a bunch of functions to take a
second flags variable, we expand the type to 64 bits via `typedef
uint64_t zio_flag_t`.
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@klarasystems.com>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Co-authored-by: Richard Yao <richard.yao@klarasystems.com>
Closes#14086
Various module parameters such as `zfs_arc_max` were originally
`uint64_t` on OpenSolaris/Illumos, but were changed to `unsigned long`
for Linux compatibility because Linux's kernel default module parameter
implementation did not support 64-bit types on 32-bit platforms. This
caused problems when porting OpenZFS to Windows because its LLP64 memory
model made `unsigned long` a 32-bit type on 64-bit, which created the
undesireable situation that parameters that should accept 64-bit values
could not on 64-bit Windows.
Upon inspection, it turns out that the Linux kernel module parameter
interface is extensible, such that we are allowed to define our own
types. Rather than maintaining the original type change via hacks to to
continue shrinking module parameters on 32-bit Linux, we implement
support for 64-bit module parameters on Linux.
After doing a review of all 64-bit kernel parameters (found via the man
page and also proposed changes by Andrew Innes), the kernel module
parameters fell into a few groups:
Parameters that were originally 64-bit on Illumos:
* dbuf_cache_max_bytes
* dbuf_metadata_cache_max_bytes
* l2arc_feed_min_ms
* l2arc_feed_secs
* l2arc_headroom
* l2arc_headroom_boost
* l2arc_write_boost
* l2arc_write_max
* metaslab_aliquot
* metaslab_force_ganging
* zfetch_array_rd_sz
* zfs_arc_max
* zfs_arc_meta_limit
* zfs_arc_meta_min
* zfs_arc_min
* zfs_async_block_max_blocks
* zfs_condense_max_obsolete_bytes
* zfs_condense_min_mapping_bytes
* zfs_deadman_checktime_ms
* zfs_deadman_synctime_ms
* zfs_initialize_chunk_size
* zfs_initialize_value
* zfs_lua_max_instrlimit
* zfs_lua_max_memlimit
* zil_slog_bulk
Parameters that were originally 32-bit on Illumos:
* zfs_per_txg_dirty_frees_percent
Parameters that were originally `ssize_t` on Illumos:
* zfs_immediate_write_sz
Note that `ssize_t` is `int32_t` on 32-bit and `int64_t` on 64-bit. It
has been upgraded to 64-bit.
Parameters that were `long`/`unsigned long` because of Linux/FreeBSD
influence:
* l2arc_rebuild_blocks_min_l2size
* zfs_key_max_salt_uses
* zfs_max_log_walking
* zfs_max_logsm_summary_length
* zfs_metaslab_max_size_cache_sec
* zfs_min_metaslabs_to_flush
* zfs_multihost_interval
* zfs_unflushed_log_block_max
* zfs_unflushed_log_block_min
* zfs_unflushed_log_block_pct
* zfs_unflushed_max_mem_amt
* zfs_unflushed_max_mem_ppm
New parameters that do not exist in Illumos:
* l2arc_trim_ahead
* vdev_file_logical_ashift
* vdev_file_physical_ashift
* zfs_arc_dnode_limit
* zfs_arc_dnode_limit_percent
* zfs_arc_dnode_reduce_percent
* zfs_arc_meta_limit_percent
* zfs_arc_sys_free
* zfs_deadman_ziotime_ms
* zfs_delete_blocks
* zfs_history_output_max
* zfs_livelist_max_entries
* zfs_max_async_dedup_frees
* zfs_max_nvlist_src_size
* zfs_rebuild_max_segment
* zfs_rebuild_vdev_limit
* zfs_unflushed_log_txg_max
* zfs_vdev_max_auto_ashift
* zfs_vdev_min_auto_ashift
* zfs_vnops_read_chunk_size
* zvol_max_discard_blocks
Rather than clutter the lists with commentary, the module parameters
that need comments are repeated below.
A few parameters were defined in Linux/FreeBSD specific code, where the
use of ulong/long is not an issue for portability, so we leave them
alone:
* zfs_delete_blocks
* zfs_key_max_salt_uses
* zvol_max_discard_blocks
The documentation for a few parameters was found to be incorrect:
* zfs_deadman_checktime_ms - incorrectly documented as int
* zfs_delete_blocks - not documented as Linux only
* zfs_history_output_max - incorrectly documented as int
* zfs_vnops_read_chunk_size - incorrectly documented as long
* zvol_max_discard_blocks - incorrectly documented as ulong
The documentation for these has been fixed, alongside the changes to
document the switch to fixed width types.
In addition, several kernel module parameters were percentages or held
ashift values, so being 64-bit never made sense for them. They have been
downgraded to 32-bit:
* vdev_file_logical_ashift
* vdev_file_physical_ashift
* zfs_arc_dnode_limit_percent
* zfs_arc_dnode_reduce_percent
* zfs_arc_meta_limit_percent
* zfs_per_txg_dirty_frees_percent
* zfs_unflushed_log_block_pct
* zfs_vdev_max_auto_ashift
* zfs_vdev_min_auto_ashift
Of special note are `zfs_vdev_max_auto_ashift` and
`zfs_vdev_min_auto_ashift`, which were already defined as `uint64_t`,
and passed to the kernel as `ulong`. This is inherently buggy on big
endian 32-bit Linux, since the values would not be written to the
correct locations. 32-bit FreeBSD was unaffected because its sysctl code
correctly treated this as a `uint64_t`.
Lastly, a code comment suggests that `zfs_arc_sys_free` is
Linux-specific, but there is nothing to indicate to me that it is
Linux-specific. Nothing was done about that.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Original-patch-by: Andrew Innes <andrew.c12@gmail.com>
Original-patch-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13984Closes#14004
ZED does not take any action for disk removal events if there is no
spare VDEV available. Added zpool_vdev_remove_wanted() in libzfs
and vdev_remove_wanted() in vdev.c to remove the VDEV through ZED
on removal event. This means that if you are running zed and
remove a disk, it will be properly marked as REMOVED.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#13797
As of the Linux 5.20 kernel bdevname() has been removed, all
callers should use snprintf() and the "%pg" format specifier.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13728
Linux 5.19 commit torvalds/linux@44abff2c0 splits the secure
erase functionality from the blkdev_issue_discard() function.
The blkdev_issue_secure_erase() must now be issued to issue
a secure erase.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13515
Linux 5.19 commit torvalds/linux@44abff2c0 removed the
blk_queue_secure_erase() helper function. The preferred
interface is to now use the bdev_max_secure_erase_sectors()
function to check for discard support.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13515
Linux 5.19 commit torvalds/linux@70200574cc removed the
blk_queue_discard() helper function. The preferred interface
is to now use the bdev_max_discard_sectors() function to check
for discard support.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13515
As for the Linux 5.18 kernel bio_alloc() expects a block_device struct
as an argument. This removes the need for the bio_set_dev() compatibility
code for 5.18 and newer kernels.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13515
bio_alloc(gfp_t gfp_mask, unsigned short nr_iovecs)
became
bio_alloc(struct block_device *bdev, unsigned short nr_vecs,
unsigned int opf, gfp_t gfp_mask)
passing NULL/0 continues previous behaviour
Upstream-commit: 07888c665b405b1cd3577ddebfeb74f4717a84c4 ("block:
pass a block_device and opf to bio_alloc")
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#13251
When using the two argument version of submit_bio() in kernel's prior
to 4.8 the first argument should be specified. It's used by block
dump to report the bio direction.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Finix Yan <yancw@info2soft.com>
Closes#13006
Evaluated every variable that lives in .data (and globals in .rodata)
in the kernel modules, and constified/eliminated/localised them
appropriately. This means that all read-only data is now actually
read-only data, and, if possible, at file scope. A lot of previously-
global-symbols became inlinable (and inlined!) constants. Probably
not in a big Wowee Performance Moment, but hey.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12899
The definition of struct blkcg_gq was moved into blk-cgroup.h, which is
a header that's been in Linux since 2015. This is used by
vdev_blkg_tryget() in module/os/linux/zfs/vdev_disk.c. Since the kernel
for CentOS 7 and similar-generation releases doesn't have this header,
its inclusion is guarded by a configure test.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12819
This change adds a confiugre check to determine if bio_set_dev is a
helper macro or not. If not, then the attempt to override its internal
call to bio_associate_blkg(), with a macro definition to our own
version, is no longer possible, as the compiler won't use it when
compiling the new inline function replacement implemented in the header.
This change also creates a new vdev_bio_set_dev() function that performs
the same work, and also performs the work implemented in
vdev_bio_associate_blkg(), as it is the only thing calling that function
in our code. Our custom vdev_bio_associate_blkg() is now only compiled
if the bio_set_dev() is a macro in the Linux headers.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12819
Due to a possible lock inversion the zvol open call path on Linux
needs to be able to retry in the case where the spa_namespace_lock
cannot be acquired.
For Linux 5.12 an older kernel this was accomplished by returning
-ERESTARTSYS from zvol_open() to request that blkdev_get() drop
the bdev->bd_mutex lock, reaquire it, then call the open callback
again. However, as of the 5.13 kernel this behavior was removed.
Therefore, for 5.12 and older kernels we preserved the existing
retry logic, but for 5.13 and newer kernels we retry internally in
zvol_open(). This should always succeed except in the case where
a pool's vdev are layed on zvols, in which case it may fail. To
handle this case vdev_disk_open() has been updated to retry when
opening a device when -ERESTARTSYS is returned.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #12301Closes#12759
The submit_bio() prototype has changed again. The version is 5.16
still only expects a single argument but the return type has changed
to void. Since we never used the returned value before update the
configure check to detect both single arg versions.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12725
The BIO_MAX_PAGES macro is being retired in favor of a bio_max_segs()
function that implements the typical MIN(x,y) logic used throughout the
kernel for bounding the allocation, and also the new implementation is
intended to be signed-safe (which the former was not).
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#11765
The struct bio member bi_disk was moved underneath a new member named
bi_bdev. So all attempts to reference bio->bi_disk need to now become
bio->bi_bdev->bd_disk.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#11639
`__vdev_disk_physio()` uses `abd_nr_pages_off()` to allocate a bio with
a sufficient number of iovec's to process this zio (i.e.
`nr_iovecs`/`bi_max_vecs`). If there are not enough iovec's in the bio,
then additional bio's will be allocated. However, this is a sub-optimal
code path. In particular, it requires several abd calls (to
`abd_nr_pages_off()` and `abd_bio_map_off()`) which will have to walk
the constituents of the ABD (the pages or the gang children) because
they are looking for offsets > 0.
For gang ABD's, `abd_nr_pages_off()` returns the number of iovec's
needed for the first constituent, rather than the sum of all
constituents (within the requested range). This always under-estimates
the required number of iovec's, which causes us to always need several
bio's. The end result is that `__vdev_disk_physio()` is usually O(n^2)
for gang ABD's (and occasionally O(n^3), when more than 16 bio's are
needed).
This commit fixes `abd_nr_pages_off()`'s handling of gang ABD's, to
correctly determine how many iovec's are needed, by adding up the number
of iovec's for each of the gang children in the requested range.
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#11536
The bd_contains member was removed from the block_device structure.
Callers needing to determine if a vdev is a whole block device should
use the new bdev_whole() wrapper. For older kernels we provide our
own bdev_whole() wrapper which relies on bd_contains for compatibility.
Reviewed-by: Rafael Kitover <rkitover@gmail.com>
Reviewed-by: Coleman Kane <ckane@colemankane.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11387Closes#11390
This patch adds a new top-level vdev type called dRAID, which stands
for Distributed parity RAID. This pool configuration allows all dRAID
vdevs to participate when rebuilding to a distributed hot spare device.
This can substantially reduce the total time required to restore full
parity to pool with a failed device.
A dRAID pool can be created using the new top-level `draid` type.
Like `raidz`, the desired redundancy is specified after the type:
`draid[1,2,3]`. No additional information is required to create the
pool and reasonable default values will be chosen based on the number
of child vdevs in the dRAID vdev.
zpool create <pool> draid[1,2,3] <vdevs...>
Unlike raidz, additional optional dRAID configuration values can be
provided as part of the draid type as colon separated values. This
allows administrators to fully specify a layout for either performance
or capacity reasons. The supported options include:
zpool create <pool> \
draid[<parity>][:<data>d][:<children>c][:<spares>s] \
<vdevs...>
- draid[parity] - Parity level (default 1)
- draid[:<data>d] - Data devices per group (default 8)
- draid[:<children>c] - Expected number of child vdevs
- draid[:<spares>s] - Distributed hot spares (default 0)
Abbreviated example `zpool status` output for a 68 disk dRAID pool
with two distributed spares using special allocation classes.
```
pool: tank
state: ONLINE
config:
NAME STATE READ WRITE CKSUM
slag7 ONLINE 0 0 0
draid2:8d:68c:2s-0 ONLINE 0 0 0
L0 ONLINE 0 0 0
L1 ONLINE 0 0 0
...
U25 ONLINE 0 0 0
U26 ONLINE 0 0 0
spare-53 ONLINE 0 0 0
U27 ONLINE 0 0 0
draid2-0-0 ONLINE 0 0 0
U28 ONLINE 0 0 0
U29 ONLINE 0 0 0
...
U42 ONLINE 0 0 0
U43 ONLINE 0 0 0
special
mirror-1 ONLINE 0 0 0
L5 ONLINE 0 0 0
U5 ONLINE 0 0 0
mirror-2 ONLINE 0 0 0
L6 ONLINE 0 0 0
U6 ONLINE 0 0 0
spares
draid2-0-0 INUSE currently in use
draid2-0-1 AVAIL
```
When adding test coverage for the new dRAID vdev type the following
options were added to the ztest command. These options are leverages
by zloop.sh to test a wide range of dRAID configurations.
-K draid|raidz|random - kind of RAID to test
-D <value> - dRAID data drives per group
-S <value> - dRAID distributed hot spares
-R <value> - RAID parity (raidz or dRAID)
The zpool_create, zpool_import, redundancy, replacement and fault
test groups have all been updated provide test coverage for the
dRAID feature.
Co-authored-by: Isaac Huang <he.huang@intel.com>
Co-authored-by: Mark Maybee <mmaybee@cray.com>
Co-authored-by: Don Brady <don.brady@delphix.com>
Co-authored-by: Matthew Ahrens <mahrens@delphix.com>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mmaybee@cray.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#10102
Kernel 5.10 removed check_disk_change() in favor of callers using
the faster bdev_check_media_change() instead, and explicitly forcing
bdev revalidation when they desire that behavior. To preserve prior
behavior, I have wrapped this into a zfs_check_media_change() macro
that calls an inline function for the new API that mimics the old
behavior when check_disk_change() doesn't exist, and just calls
check_disk_change() if it exists.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#11085
Kernel commit 2b0d3d3e4fcfb brought in some changes to the struct
percpu_ref structure that moves most of its fields into a member
struct named "data" of type struct percpu_ref_data. This includes
the "count" member which is updated by vdev_blkg_tryget(), so update
this function to chase the API change, and detect it via configure.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#11085
With PREEMPTION=y and BLK_CGROUP=y preempt_schedule_notrace() is being
used on arm64 which is a GPL-only function and hence the build of the
DKMS kernel module fails.
Fix that by redefining preempt_schedule_notrace() to preempt_schedule()
which should be safe as long as tracing is not used.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Closes#8545Closes#9948Closes#10416Closes#10973
When expanding a device zfs needs to rescan the partition table to
get the correct size. This can only happen when we're in the kernel
and requires the device to be closed. As part of the rescan, udev is
notified and the device links are removed and recreated. This leave a
window where the vdev code may try to reopen the device before udev
has recreated the link. If that happens, then the pool may end up in
a suspended state.
To correct this, we leverage the BLKPG_RESIZE_PARTITION ioctl which
allows the partition information to be modified even while it's in use.
This ioctl also does not remove the device link associated with the zfs
data partition so it eliminates the race condition that can occur in
the kernel.
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Wilson <gwilson@delphix.com>
Closes#10897
Many modern devices use physical allocation units that are much
larger than the minimum logical allocation size accessible by
external commands. Two prevalent examples of this are 512e disk
drives (512b logical sector, 4K physical sector) and flash devices
(512b logical sector, 4K or larger allocation block size, and 128k
or larger erase block size). Operations that modify less than the
physical sector size result in a costly read-modify-write or garbage
collection sequence on these devices.
Simply exporting the true physical sector of the device to ZFS would
yield optimal performance, but has two serious drawbacks:
1. Existing pools created with devices that have different logical
and physical block sizes, but were configured to use the logical
block size (e.g. because the OS version used for pool construction
reported the logical block size instead of the physical block
size) will suddenly find that the vdev allocation size has
increased. This can be easily tolerated for active members of
the array, but ZFS would prevent replacement of a vdev with
another identical device because it now appears that the smaller
allocation size required by the pool is not supported by the new
device.
2. The device's physical block size may be too large to be supported
by ZFS. The optimal allocation size for the vdev may be quite
large. For example, a RAID controller may export a vdev that
requires read-modify-write cycles unless accessed using 64k
aligned/sized requests. ZFS currently has an 8k minimum block
size limit.
Reporting both the logical and physical allocation sizes for vdevs
solves these problems. A device may be used so long as the logical
block size is compatible with the configuration. By comparing the
logical and physical block sizes, new configurations can be optimized
and administrators can be notified of any existing pools that are
sub-optimal.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Matthew Macy <mmacy@freebsd.org>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#10619
Linux defines different vdev_disk_t members to macOS, but they are
only used in vdev_disk.c so move the declaration there.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#10452
Adding the gang ABD type, which allows for linear and scatter ABDs to
be chained together into a single ABD.
This can be used to avoid doing memory copies to/from ABDs. An example
of this can be found in vdev_queue.c in the vdev_queue_aggregate()
function.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Brian <bwa@clemson.edu>
Co-authored-by: Mark Maybee <mmaybee@cray.com>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#10069
Commit https://github.com/torvalds/linux/commit/9e8d42a0f accidentally
converted the static inline function blkg_tryget() to GPL-only for
kernels built with CONFIG_PREEMPT_RCU=y and CONFIG_BLK_CGROUP=y.
Resolve the build issue by providing our own equivalent functionality
when needed which uses rcu_read_lock_sched() internally as before.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#9745Closes#10072
Update the vdev_disk_open() retry logic to use a specified number
of milliseconds to be more robust. Additionally, on failure log
both the time waited and requested timeout to the internal log.
The default maximum allowed open retry time has been increased
from 500ms to 1000ms.
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#9680
As described in commit f81d5ef6 the zfs_vdev_elevator module
option is being removed. Users who require this functionality
should update their systems to set the disk scheduler using a
udev rule.
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #8664Closes#9417Closes#9609
Provide a common zfs_file_* interface which can be implemented on all
platforms to perform normal file access from either the kernel module
or the libzpool library.
This allows all non-portable vnode_t usage in the common code to be
replaced by the new portable zfs_file_t. The associated vnode and
kobj compatibility functions, types, and macros have been removed
from the SPL. Moving forward, vnodes should only be used in platform
specific code when provided by the native operating system.
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#9556
blkg_tryget() as shipped in EL8 kernels does not seem to handle NULL
@blkg as input; this is different from its mainline counterpart where
NULL is accepted. To prevent dereferencing a NULL pointer when dealing
with block devices which do not set a root_blkg on the request queue
perform the NULL check in vdev_bio_associate_blkg().
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#9546Closes#9577
Increase the minimum supported kernel version from 2.6.32 to 3.10.
This removes support for the following Linux enterprise distributions.
Distribution | Kernel | End of Life
---------------- | ------ | -------------
Ubuntu 12.04 LTS | 3.2 | Apr 28, 2017
SLES 11 | 3.0 | Mar 32, 2019
RHEL / CentOS 6 | 2.6.32 | Nov 30, 2020
The following changes were made as part of removing support.
* Updated `configure` to enforce a minimum kernel version as
specified in the META file (Linux-Minimum: 3.10).
configure: error:
*** Cannot build against kernel version 2.6.32.
*** The minimum supported kernel version is 3.10.
* Removed all `configure` kABI checks and matching C code for
interfaces which solely predate the Linux 3.10 kernel.
* Updated all `configure` kABI checks to fail when an interface is
missing which was in the 3.10 kernel up to the latest 5.1 kernel.
Removed the HAVE_* preprocessor defines for these checks and
updated the code to unconditionally use the verified interface.
* Inverted the detection logic in several kABI checks to match
the new interface as it appears in 3.10 and newer and not the
legacy interface.
* Consolidated the following checks in to individual files. Due
the large number of changes in the checks it made sense to handle
this now. It would be desirable to group other related checks in
the same fashion, but this as left as future work.
- config/kernel-blkdev.m4 - Block device kABI checks
- config/kernel-blk-queue.m4 - Block queue kABI checks
- config/kernel-bio.m4 - Bio interface kABI checks
* Removed the kABI checks for sops->nr_cached_objects() and
sops->free_cached_objects(). These interfaces are currently unused.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#9566
In the FreeBSD kernel the strdup signature is:
```
char *strdup(const char *__restrict, struct malloc_type *);
```
It's unfortunate that the developers have chosen to change
the signature of libc functions - but it's what I have to
deal with.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#9433
