Rob Noris suggested that we could clean up redundant limits for the case
of non-blk mq scenario.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#16462
In kernels 6.8 and later, the zvol block device is allocated with
qlimits passed during initialization. However, the zvol driver does not
set `max_hw_discard_sectors`, which is necessary to properly
initialize `max_discard_sectors`. This causes the `zvol_misc_trim` test
to fail on 6.8+ kernels when invoking the `blkdiscard` command. Setting
`max_hw_discard_sectors` in the `HAVE_BLK_ALLOC_DISK_2ARG` case resolve
the issue.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#16462
zvol queue limits initialization depends on `zv_volblocksize`, but it is
initialized later, leading to several limits being initialized with
incorrect values, including `max_discard_*` limits. This also causes
`blkdiscard` command to consistently fail, as `blk_ioctl_discard` reads
`bdev_max_discard_sectors()` limits as 0, leading to failure. The fix is
straightforward: initialize `zv->zv_volblocksize` early, before setting
the queue limits. This PR should fix `zvol/zvol_misc/zvol_misc_trim`
failure on recent PRs, as the test case issues `blkdiscard` for a zvol.
Additionally, `zvol_misc_trim` was recently enabled in `6c7d41a`,
which is why the issue wasn't identified earlier.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#16454
zvol_alloc_non_blk_mq()->blk_queue_set_write_cache() needs the disk
queue setup to prevent a NULL pointer deference.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#16453
These fields are very old, so no detection necessary; we just move them
into the limit setup functions.
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#16400
Apply them with with the rest of the settings.
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#16400
In 6.11 struct queue_limits gains a 'features' field, where, among other
things, flush and write-cache are enabled. Detect it and use it.
Along the way, the blk_queue_set_write_cache() compat wrapper gets a
little cleanup. Since both flags are alway set together, its now a
single bool. Also the very very ancient version that sets q->flush_flags
directly couldn't actually turn it off, so I've fixed that. Not that we
use it, but still.
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#16400
It gets hairier again in Linux 6.11, so I want some actual theory of
operation laid out for next time.
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#16400
Currently, if a minor is in use when we try to remove it, we'll skip it
and never come back to it again. Since the zvol state is hung off the
minor in the kernel, this can get us into weird situations if something
tries to use it after the removal fails. It's even worse at pool export,
as there's now a vestigial zvol state with no pool under it. It's
weirder again if the pool is subsequently reimported, as the zvol code
(reasonably) assumes the zvol state has been properly setup, when it's
actually left over from the previous import of the pool.
This commit attempts to tackle that by setting a flag on the zvol if its
minor can't be removed, and then checking that flag when a request is
made and rejecting it, thus stopping new work coming in.
The flag also causes a condvar to be signaled when the last client
finishes. For the case where a single minor is being removed (eg
changing volmode), it will wait for this signal before proceeding.
Meanwhile, when removing all minors, a background task is created for
each minor that couldn't be removed on the spot, and those tasks then
wake and clean up.
Since any new tasks are queued on to the pool's spa_zvol_taskq,
spa_export_common() will continue to wait at export until all minors are
removed.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#14872Closes#16364
SET_ERROR is our facility for tracking errors internally. The negation
is to match the what the kernel expects from us. Thus, the negation
should happen outside of the SET_ERROR.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes#16364
Linux has started moving to a model where instead of applying block
queue limits through individual modification functions, a complete
limits structure is built up and applied atomically, either when the
block device or open, or some time afterwards. As of 6.10 this
transition appears only partly completed.
This commit matches that model within OpenZFS in a way that should work
for past and future kernels. We set up a queue limits structure with any
limits that have had their modification functions removed. For newer
kernels that can have limits applied at block device open
(HAVE_BLK_ALLOC_DISK_2ARG), we have a conversion function to turn the
OpenZFS queue limits structure into Linux's queue_limits structure,
which can then be passed in. For older kernels, we provide an
application function that just calls the old functions for each limit in
the structure.
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
In several functions, we use a flag variable to track whether
zv_suspend_lock is held. This flag was not getting reset in a
particular case where we need to retry the underlying operation,
resulting in a lock leak. Make sure to update the flag where necessary.
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
The 6.9 kernel behaves differently in how it releases block devices. In
the common case it will async release the device only after the return
to userspace. This is different from the 6.8 and older kernels which
release the block devices synchronously. To get around this, call
add_disk() from a workqueue so that the kernel uses a different
codepath to release our zvols in the way we expect. This stops
zfs_allow_010_pos from hanging.
Fixes: #16089
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Rob Norris <rob.norris@klarasystems.com>
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
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
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
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
- Remove zsda_tx field, it is used only once.
- Remove unneeded string lengths checks, all names are terminated.
- Replace few explicit MAXNAMELEN usages with sizeof().
- Change dsname from MAXNAMELEN to ZFS_MAX_DATASET_NAME_LEN, as
expected by dsl_dataset_name(). Both are 256 bytes now, but it is
better to be safe.
This should have no functional difference.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#15535
Add a dataset_kstats_rename function, and call it when renaming
a zvol on FreeBSD and Linux.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alan Somers <asomers@gmail.com>
Sponsored-by: Axcient
Closes#15482Closes#15486
Currently, zvol threading can be switched through the zvol_request_sync
module parameter system-wide. By making it a zvol property, zvol
threading can be switched per zvol.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#15409
ZVOL:
- Mark all ZVOL ZIL transactions as sync. Since ZVOLs have only
one object, it makes no sense to maintain async queue and on each
commit merge it into sync. Single sync queue is just cheaper, while
it changes nothing until actual commit request arrives.
- Remove zsd_sync_cnt and the zil_async_to_sync() calls since we
are no longer switching between sync and async queues.
ZFS:
- Mark write transactions as sync based only on number of sync
opens (z_sync_cnt). We can not randomly jump between sync and
async unless we want data corruptions due to writes reordering.
- When file first opened with O_SYNC (z_sync_cnt incremented to 1)
call zil_async_to_sync() for it to preserve correct ordering between
past and future writes.
- Drop zfs_fsyncer_key logic. Looks like it was an optimization
for workloads heavily intermixing async writes with tons of fsyncs.
But first it was broken 8 years ago due to Linux tsd implementation
not allowing data storage between syscalls, and second, I doubt it
is safe to switch from async to sync so often and without calling
zil_async_to_sync().
- Rename sync argument of *_log_write() into commit, now only
signalling caller's intent to call zil_commit() soon after. It
allows WR_COPIED optimizations without extra other meanings.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#15366
This reverts commit aefb6a2bd6.
aefb6a2bd temporally disabled blk-mq until we could fix a fix for
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#15439
There was a report of zvol data loss (#15351) after enabling blk-mq on a
zvol backed with 16k physical block sized disks. Out of an abundance of
caution, do not allow the user to enable blk-mq until we can look into
the issue.
Note that blk-mq was not enabled by default on zvols. It was always
opt-in via the zvol_use_blk_mq module parameter.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Addresses: #15351Closes#15378
In Linux commit 560e20e4bf6484a0c12f9f3c7a1aa55056948e1e, the
fsync_bdev() function was removed in favor of sync_blockdev() to do
(roughly) the same thing, given the same input. This change
conditionally attempts to call sync_blockdev() if fsync_bdev() isn't
discovered during configure.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#15263
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
The default timeout for ZVOL opens may not be sufficient for all cases,
so we should enable the value to be more easily tuned to account for
systems where the default value is insufficient.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Closes#15023
If there were no zil entries to replay, skip zil_close. zil_close waits
for a transaction to sync. That can take several seconds, for example
during pool import of a resilvering pool. Skipping zil_close can cut
the time for "zpool import" from 2 hours to 45 seconds on a resilvering
pool with a thousand zvols.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Sponsored-by: Axcient
Closes#13999Closes#14015
This patch inserts the `static` keyword to non-global variables,
which where found by the analysis tool smatch.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes#13970
Coverity found a number of places where we either do MAX(unsigned, 0) or
do assertions that a unsigned variable is >= 0. These do nothing, so
let us drop them all.
It also found a spot where we do `if (unsigned >= 0 && ...)`. Let us
also drop the unsigned >= 0 check.
Reviewed-by: Neal Gompa <ngompa@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13871
As of the Linux 5.20 kernel blk_cleanup_disk() has been removed,
all callers should use put_disk().
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13728
ZIL kstats are reported in an inclusive way, i.e., same counters are
shared to capture all the activities happening in zil. Added support
to report zil stats for every datset individually by combining them
with already exposed dataset kstats.
Wmsum uses per cpu counters and provide less overhead as compared
to atomic operations. Updated zil kstats to replace wmsum counters
to avoid atomic operations.
Reviewed-by: Christian Schwarz <christian.schwarz@nutanix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#13636
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver. blk-mq creates multiple request queues on
different CPUs rather than having a single request queue. This can
improve zvol performance with multithreaded reads/writes.
This implementation uses the blk-mq interfaces on 4.13 or newer
kernels. Building against older kernels will fall back to the
older BIO interfaces.
Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API. It is disabled by default.
In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs. This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.
sequential dd to one zvol, 8k volblocksize, no O_DIRECT:
legacy submit_bio() 292MB/s write 453MB/s read
this commit 453MB/s write 885MB/s read
It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread. It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#13148
Issue #12483
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 of the 5.17 kernel the GENHD_FL_EXT_DEVT flag has been removed
and the GENHD_FL_NO_PART_SCAN flag renamed GENHD_FL_NO_PART. Update
zvol_alloc() to set GENHD_FL_NO_PART for the newer kernels which
is sufficient. The behavior for prior kernels remains unchanged.
1ebe2e5f ("block: remove GENHD_FL_EXT_DEVT")
46e7eac6 ("block: rename GENHD_FL_NO_PART_SCAN to GENHD_FL_NO_PART")
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13294Closes#13297
When HAVE_BLKDEV_GET_ERESTARTSYS is defined, compiler will complain
"defined but not used" warning for zvol_open_timeout_ms.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ping Huang <huangping@smartx.com>
Closes#13270
blkdev.h includes genhd.h since dawn of upstream git, so this is
globally safe
Upstream-commit: 322cbb50de711814c42fb088f6d31901502c711a ("block:
remove genhd.h")
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#13251
There's no need to make the platform ops dynamic dispatch.
This change replaces the dynamic dispatch with static calls to the
platform-specific functions.
To avoid name collisions, prefix all platform-specific functions
with `zvol_os_`.
I actually find `zvol_..._os` slightly nicer to read in the calling
code, but having it as a prefix is useful.
Advantage:
- easier jump-to-definition / grepping
- potential benefits to static analysis
- better legibility
Future work: also prefix remaining `static` functions in zvol_os.c.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Christian Schwarz <christian.schwarz@nutanix.com>
Closes#12965
add_disk went from void to must-check int return.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Coleman Kane <ckane@colemankane.org>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12975
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
When restructuring the zvol_open() logic for the Linux 5.13 kernel
a lock inversion was accidentally introduced. In the updated code
the spa_namespace_lock is now taken before the zv_suspend_lock
allowing the following scenario to occur:
down_read <=== waiting for zv_suspend_lock
zvol_open <=== holds spa_namespace_lock
__blkdev_get
blkdev_get_by_dev
blkdev_open
...
mutex_lock <== waiting for spa_namespace_lock
spa_open_common
spa_open
dsl_pool_hold
dmu_objset_hold_flags
dmu_objset_hold
dsl_prop_get
dsl_prop_get_integer
zvol_create_minor
dmu_recv_end
zfs_ioc_recv_impl <=== holds zv_suspend_lock via zvol_suspend()
zfs_ioc_recv
...
This commit resolves the issue by moving the acquisition of the
spa_namespace_lock back to after the zv_suspend_lock which restores
the original ordering.
Additionally, as part of this change the error exit paths were
simplified where possible.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12863
