The function disk_update_zone_resources() may call
disk_free_zone_resources() in case of error, and following this,
blk_revalidate_disk_zones() will again calls disk_free_zone_resources() if
disk_update_zone_resources() failed. If a zone worker thread is being used
(which is the default for a rotational media zoned device),
disk_free_zone_resources() will try to stop the zone worker thread twice
because disk->zone_wplugs_worker is not reset to NULL when the worker
thread is stopped the first time.
In disk_free_zone_resources(), fix this by correctly clearing
disk->zone_wplugs_worker to NULL when the worker thread is stopped.
And while at it, since disk_free_zone_resources() is always called after a
failed call to disk_update_zone_resources(), remove the unnecessary call
to disk_free_zone_resources() in disk_update_zone_resources().
Fixes: 1365b6904f ("block: allow submitting all zone writes from a single context")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260522115622.588535-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Shin'ichiro reported hard to reproduce unaligned write errors with zoned
block devices. Under normal operation conditions (e.g. running XFS on an
SMR disk), these errors are nearly impossible to trigger. But using a
"slow" kernel with many debug options enables and some specific use
cases (e.g. fio zbd test case 46), the errors can be reproduced fairly
easily.
The unaligned write errors come from mishandling a valid reference
counting pattern of zone write plugs. Such pattern triggers for instance
if a process A writes a zone (not necessarilly to the full state),
another process B immediately resets the zone and immediately following
the completion of the zone reset, starts issuing writes to the zone.
With such pattern, in some cases, the zone write plugs worker thread of
the device may still be holding a reference to the zone write plug of
the zone taken when process A was writing to the zone. The following
zone reset from process B marks the zone as dead but does not remove the
zone write plug from the device hash table as a reference to the plug
still exist. Once process B starts issuing new writes, the zone write
plug is seen as dead and the writes from process B are immediately
failed, despite this write pattern being perfectly legal.
Fix this by allowing restoring a dead zone write plug to a live state if
a write is issued to the zone when the zone is: marked as dead, empty
and the write sector corresponds to the first sector of the zone (that
is, the write is aligned to the zone write pointer). This is done with
the new helper function disk_check_zone_wplug_dead(), which restores a
dead zone write plug to a live state by clearing the BLK_ZONE_WPLUG_DEAD
flag and restoring the initial reference to the zone write plug taken
when the plug was added to the device hash table.
Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: b7d4ffb510 ("block: fix zone write plug removal")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://patch.msgid.link/20260513111129.108809-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Split the zone reset case into a separate helper so that the conditional
locking goes away.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://patch.msgid.link/20260327090032.3722065-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When blk_revalidate_disk_zones() fails after disk_revalidate_zone_resources()
has allocated args.zones_cond, the memory is leaked because no error path
frees it.
Fixes: 6e945ffb65 ("block: use zone condition to determine conventional zones")
Suggested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Link: https://patch.msgid.link/20260331111216.24242-1-liu.yun@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In order to maintain sequential write patterns per zone with zoned block
devices, zone write plugging issues only a single write BIO per zone at
any time. This works well but has the side effect that when large
sequential write streams are issued by the user and these streams cross
zone boundaries, the device ends up receiving a discontiguous set of
write commands for different zones. The same also happens when a user
writes simultaneously at high queue depth multiple zones: the device
does not see all sequential writes per zone and receives discontiguous
writes to different zones. While this does not affect the performance of
solid state zoned block devices, when using an SMR HDD, this pattern
change from sequential writes to discontiguous writes to different zones
significantly increases head seek which results in degraded write
throughput.
In order to reduce this seek overhead for rotational media devices,
introduce a per disk zone write plugs kernel thread to issue all write
BIOs to zones. This single zone write issuing context is enabled for
any zoned block device that has a request queue flagged with the new
QUEUE_ZONED_QD1_WRITES flag.
The flag QUEUE_ZONED_QD1_WRITES is visible as the sysfs queue attribute
zoned_qd1_writes for zoned devices. For regular block devices, this
attribute is not visible. For zoned block devices, a user can override
the default value set to force the global write maximum queue depth of
1 for a zoned block device, or clear this attribute to fallback to the
default behavior of zone write plugging which limits writes to QD=1 per
sequential zone.
Writing to a zoned block device flagged with QUEUE_ZONED_QD1_WRITES is
implemented using a list of zone write plugs that have a non-empty BIO
list. Listed zone write plugs are processed by the disk zone write plugs
worker kthread in FIFO order, and all BIOs of a zone write plug are all
processed before switching to the next listed zone write plug. A newly
submitted BIO for a non-FULL zone write plug that is not yet listed
causes the addition of the zone write plug at the end of the disk list
of zone write plugs.
Since the write BIOs queued in a zone write plug BIO list are
necessarilly sequential, for rotational media, using the single zone
write plugs kthread to issue all BIOs maintains a sequential write
pattern and thus reduces seek overhead and improves write throughput.
This processing essentially result in always writing to HDDs at QD=1,
which is not an issue for HDDs operating with write caching enabled.
Performance with write cache disabled is also not degraded thanks to
the efficient write handling of modern SMR HDDs.
A disk list of zone write plugs is defined using the new struct gendisk
zone_wplugs_list, and accesses to this list is protected using the
zone_wplugs_list_lock spinlock. The per disk kthread
(zone_wplugs_worker) code is implemented by the function
disk_zone_wplugs_worker(). A reference on listed zone write plugs is
always held until all BIOs of the zone write plug are processed by the
worker kthread. BIO issuing at QD=1 is driven using a completion
structure (zone_wplugs_worker_bio_done) and calls to blk_io_wait().
With this change, performance when sequentially writing the zones of a
30 TB SMR SATA HDD connected to an AHCI adapter changes as follows
(1MiB direct I/Os, results in MB/s unit):
+--------------------+
| Write BW (MB/s) |
+------------------+----------+---------+
| Sequential write | Baseline | Patched |
| Queue Depth | 6.19-rc8 | |
+------------------+----------+---------+
| 1 | 244 | 245 |
| 2 | 244 | 245 |
| 4 | 245 | 245 |
| 8 | 242 | 245 |
| 16 | 222 | 246 |
| 32 | 211 | 245 |
| 64 | 193 | 244 |
| 128 | 112 | 246 |
+------------------+----------+---------+
With the current code (baseline), as the sequential write stream crosses
a zone boundary, higher queue depth creates a gap between the
last IO to the previous zone and the first IOs to the following zones,
causing head seeks and degrading performance. Using the disk zone
write plugs worker thread, this pattern disappears and the maximum
throughput of the drive is maintained, leading to over 100%
improvements in throughput for high queue depth write.
Using 16 fio jobs all writing to randomly chosen zones at QD=32 with 1
MiB direct IOs, write throughput also increases significantly.
+--------------------+
| Write BW (MB/s) |
+------------------+----------+---------+
| Random write | Baseline | Patched |
| Number of zones | 6.19-rc7 | |
+------------------+----------+---------+
| 1 | 191 | 192 |
| 2 | 101 | 128 |
| 4 | 115 | 123 |
| 8 | 90 | 120 |
| 16 | 64 | 115 |
| 32 | 58 | 105 |
| 64 | 56 | 101 |
| 128 | 55 | 99 |
+------------------+----------+---------+
Tests using XFS shows that buffered write speed with 8 jobs writing
files increases by 12% to 35% depending on the workload.
+--------------------+
| Write BW (MB/s) |
+------------------+----------+---------+
| Workload | Baseline | Patched |
| | 6.19-rc7 | |
+------------------+----------+---------+
| 256MiB file size | 212 | 238 |
+------------------+----------+---------+
| 4MiB .. 128 MiB | 213 | 243 |
| random file size | | |
+------------------+----------+---------+
| 2MiB .. 8 MiB | 179 | 242 |
| random file size | | |
+------------------+----------+---------+
Performance gains are even more significant when using an HBA that
limits the maximum size of commands to a small value, e.g. HBAs
controlled with the mpi3mr driver limit commands to a maximum of 1 MiB.
In such case, the write throughput gains are over 40%.
+--------------------+
| Write BW (MB/s) |
+------------------+----------+---------+
| Workload | Baseline | Patched |
| | 6.19-rc7 | |
+------------------+----------+---------+
| 256MiB file size | 175 | 245 |
+------------------+----------+---------+
| 4MiB .. 128 MiB | 174 | 244 |
| random file size | | |
+------------------+----------+---------+
| 2MiB .. 8 MiB | 171 | 243 |
| random file size | | |
+------------------+----------+---------+
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Rename struct gendisk zone_wplugs_lock field to zone_wplugs_hash_lock to
clearly indicates that this is the spinlock used for manipulating the
hash table of zone write plugs.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The helper function disk_zone_is_full() is only used in
disk_zone_wplug_is_full(). So remove it and open code it directly in
this single caller.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
disk_get_and_lock_zone_wplug() always returns a zone write plug with the
plug lock held. This is unnecessary since this function does not look at
the fields of existing plugs, and new plugs need to be locked only after
their insertion in the disk hash table, when they are being used.
Remove the zone write plug locking from disk_get_and_lock_zone_wplug()
and rename this function disk_get_or_alloc_zone_wplug().
blk_zone_wplug_handle_write() is modified to add locking of the zone
write plug after calling disk_get_or_alloc_zone_wplug() and before
starting to use the plug. This change also simplifies
blk_revalidate_seq_zone() as unlocking the plug becomes unnecessary.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The function disk_zone_wplug_schedule_bio_work() always takes a
reference on the zone write plug of the BIO work being scheduled. This
ensures that the zone write plug cannot be freed while the BIO work is
being scheduled but has not run yet. However, this unconditional
reference taking is fragile since the reference taken is released by the
BIO work blk_zone_wplug_bio_work() function, which implies that there
always must be a 1:1 relation between the work being scheduled and the
work running.
Make sure to drop the reference taken when scheduling the BIO work if
the work is already scheduled, that is, when queue_work() returns false.
Fixes: 9e78c38ab3 ("block: Hold a reference on zone write plugs to schedule submission")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 7b29518728 ("block: Do not remove zone write plugs still in
use") modified disk_should_remove_zone_wplug() to add a check on the
reference count of a zone write plug to prevent removing zone write
plugs from a disk hash table when the plugs are still being referenced
by BIOs or requests in-flight. However, this check does not take into
account that a BIO completion may happen right after its submission by
a zone write plug BIO work, and before the zone write plug BIO work
releases the zone write plug reference count. This situation leads to
disk_should_remove_zone_wplug() returning false as in this case the zone
write plug reference count is at least equal to 3. If the BIO that
completes in such manner transitioned the zone to the FULL condition,
the zone write plug for the FULL zone will remain in the disk hash
table.
Furthermore, relying on a particular value of a zone write plug
reference count to set the BLK_ZONE_WPLUG_UNHASHED flag is fragile as
reading the atomic reference count and doing a comparison with some
value is not overall atomic at all.
Address these issues by reworking the reference counting of zone write
plugs so that removing plugs from a disk hash table can be done
directly from disk_put_zone_wplug() when the last reference on a plug
is dropped.
To do so, replace the function disk_remove_zone_wplug() with
disk_mark_zone_wplug_dead(). This new function sets the zone write plug
flag BLK_ZONE_WPLUG_DEAD (which replaces BLK_ZONE_WPLUG_UNHASHED) and
drops the initial reference on the zone write plug taken when the plug
was added to the disk hash table. This function is called either for
zones that are empty or full, or directly in the case of a forced plug
removal (e.g. when the disk hash table is being destroyed on disk
removal). With this change, disk_should_remove_zone_wplug() is also
removed.
disk_put_zone_wplug() is modified to call the function
disk_free_zone_wplug() to remove a zone write plug from a disk hash
table and free the plug structure (with a call_rcu()), when the last
reference on a zone write plug is dropped. disk_free_zone_wplug()
always checks that the BLK_ZONE_WPLUG_DEAD flag is set.
In order to avoid having multiple zone write plugs for the same zone in
the disk hash table, disk_get_and_lock_zone_wplug() checked for the
BLK_ZONE_WPLUG_UNHASHED flag. This check is removed and a check for
the new BLK_ZONE_WPLUG_DEAD flag is added to
blk_zone_wplug_handle_write(). With this change, we continue preventing
adding multiple zone write plugs for the same zone and at the same time
re-inforce checks on the user behavior by failing new incoming write
BIOs targeting a zone that is marked as dead. This case can happen only
if the user erroneously issues write BIOs to zones that are full, or to
zones that are currently being reset or finished.
Fixes: 7b29518728 ("block: Do not remove zone write plugs still in use")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
-----BEGIN PGP SIGNATURE-----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=jNzW
-----END PGP SIGNATURE-----
Merge tag 'for-7.0/block-20260206' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull block updates from Jens Axboe:
- Support for batch request processing for ublk, improving the
efficiency of the kernel/ublk server communication. This can yield
nice 7-12% performance improvements
- Support for integrity data for ublk
- Various other ublk improvements and additions, including a ton of
selftests additions and updated
- Move the handling of blk-crypto software fallback from below the
block layer to above it. This reduces the complexity of dealing with
bio splitting
- Series fixing a number of potential deadlocks in blk-mq related to
the queue usage counter and writeback throttling and rq-qos debugfs
handling
- Add an async_depth queue attribute, to resolve a performance
regression that's been around for a qhilw related to the scheduler
depth handling
- Only use task_work for IOPOLL completions on NVMe, if it is necessary
to do so. An earlier fix for an issue resulted in all these
completions being punted to task_work, to guarantee that completions
were only run for a given io_uring ring when it was local to that
ring. With the new changes, we can detect if it's necessary to use
task_work or not, and avoid it if possible.
- rnbd fixes:
- Fix refcount underflow in device unmap path
- Handle PREFLUSH and NOUNMAP flags properly in protocol
- Fix server-side bi_size for special IOs
- Zero response buffer before use
- Fix trace format for flags
- Add .release to rnbd_dev_ktype
- MD pull requests via Yu Kuai
- Fix raid5_run() to return error when log_init() fails
- Fix IO hang with degraded array with llbitmap
- Fix percpu_ref not resurrected on suspend timeout in llbitmap
- Fix GPF in write_page caused by resize race
- Fix NULL pointer dereference in process_metadata_update
- Fix hang when stopping arrays with metadata through dm-raid
- Fix any_working flag handling in raid10_sync_request
- Refactor sync/recovery code path, improve error handling for
badblocks, and remove unused recovery_disabled field
- Consolidate mddev boolean fields into mddev_flags
- Use mempool to allocate stripe_request_ctx and make sure
max_sectors is not less than io_opt in raid5
- Fix return value of mddev_trylock
- Fix memory leak in raid1_run()
- Add Li Nan as mdraid reviewer
- Move phys_vec definitions to the kernel types, mostly in preparation
for some VFIO and RDMA changes
- Improve the speed for secure erase for some devices
- Various little rust updates
- Various other minor fixes, improvements, and cleanups
* tag 'for-7.0/block-20260206' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (162 commits)
blk-mq: ABI/sysfs-block: fix docs build warnings
selftests: ublk: organize test directories by test ID
block: decouple secure erase size limit from discard size limit
block: remove redundant kill_bdev() call in set_blocksize()
blk-mq: add documentation for new queue attribute async_dpeth
block, bfq: convert to use request_queue->async_depth
mq-deadline: covert to use request_queue->async_depth
kyber: covert to use request_queue->async_depth
blk-mq: add a new queue sysfs attribute async_depth
blk-mq: factor out a helper blk_mq_limit_depth()
blk-mq-sched: unify elevators checking for async requests
block: convert nr_requests to unsigned int
block: don't use strcpy to copy blockdev name
blk-mq-debugfs: warn about possible deadlock
blk-mq-debugfs: add missing debugfs_mutex in blk_mq_debugfs_register_hctxs()
blk-mq-debugfs: remove blk_mq_debugfs_unregister_rqos()
blk-mq-debugfs: make blk_mq_debugfs_register_rqos() static
blk-rq-qos: fix possible debugfs_mutex deadlock
blk-mq-debugfs: factor out a helper to register debugfs for all rq_qos
blk-wbt: fix possible deadlock to nest pcpu_alloc_mutex under q_usage_counter
...
Any queue_limits_start_update() call must be followed either by a
queue_limits_commit_update() call or by a queue_limits_cancel_update()
call. Make sure that the error path near the start of
disk_update_zone_resources() follows this requirement. Remove the
"goto unfreeze" statement from that error path to make the code easier
to verify.
This was detected by annotating the queue_limits_*() calls with Clang
thread-safety attributes and by building the kernel with thread-safety
checking enabled. Without this patch and with thread-safety checking
enabled, the following error is reported:
block/blk-zoned.c:2020:1: error: mutex 'disk->queue->limits_lock' is not held on every path through here [-Werror,-Wthread-safety-analysis]
2020 | }
| ^
block/blk-zoned.c:1959:8: note: mutex acquired here
1959 | lim = queue_limits_start_update(q);
| ^
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Fixes: bba4322e3f ("block: freeze queue when updating zone resources")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20260114192803.4171847-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fix the comment for blk_zone_cond_str() by replacing the meaningless
BLK_ZONE_ZONE_XXX comment with the correct BLK_ZONE_COND_name, thus also
replacing the XXX with what that actually means.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When mounting a btrfs file system on virtio-blk which supports native
Zone Append there has been a WARN triggering in btrfs' space management
code.
Further looking into btrfs' zoned statistics uncovered the filesystem
expecting the zones to be used, but the write pointers being 0:
# cat /sys/fs/btrfs/8eabd2e7-3294-4f9e-9b58-7e64135c8bf4/zoned_stats
active block-groups: 4
reclaimable: 0
unused: 0
need reclaim: false
data relocation block-group: 1342177280
active zones:
start: 1073741824, wp: 0 used: 0, reserved: 0, unusable: 0
start: 1342177280, wp: 0 used: 0, reserved: 0, unusable: 0
start: 1610612736, wp: 0 used: 16384, reserved: 0, unusable: 18446744073709535232
start: 1879048192, wp: 0 used: 131072, reserved: 0, unusable: 18446744073709420544
Looking at the blkzone report output for the zone in question
(1610612736) the write pointer on the device moved, but the filesystem
did not see a change on the write pointer:
# blkzone report -c 1 -o 0x300000 /dev/vda
start: 0x000300000, len 0x080000, cap 0x080000, wptr 0x000040 reset:0 non-seq:0, zcond: 2(oi) [type: 2(SEQ_WRITE_REQUIRED)]
The zone write pointer is 0, because btrfs is using the cached version
of blkdev_report_zones() and as virtio-blk is supporting native zone
append, but blkdev_revalidate_zones() does not initialize the zone write
plugs in this case.
Not skipping the revalidate of sequential zones in
blkdev_revalidate_zones() callchain fixes this issue.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Fixes: a6aa36e957 ("block: Remove zone write plugs when handling native zone append writes")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit fe0418eb9b ("block: Prevent potential deadlocks in zone write
plug error recovery") added a WARN check in disk_put_zone_wplug() to
verify that when the last reference to a zone write plug is dropped,
this zone write plug does not have the BLK_ZONE_WPLUG_PLUGGED flag set,
that is, that it is not plugged.
However, the function disk_zone_wplug_abort(), which is called for zone
reset and zone finish operations, does not clear this flag after
emptying a zone write plug BIO list. This can result in the
disk_put_zone_wplug() warning to trigger if the user (erroneously as
that is bad pratcice) issues zone reset or zone finish operations while
the target zone still has plugged BIOs.
Modify disk_put_zone_wplug() to clear the BLK_ZONE_WPLUG_PLUGGED flag.
And while at it, also add a lockdep annotation to ensure that this
function is called with the zone write plug spinlock held.
Fixes: fe0418eb9b ("block: Prevent potential deadlocks in zone write plug error recovery")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 2284eec5053d ("block: introduce blkdev_get_zone_info()")
introduced the report_active field in struct blk_report_zones_args so
that open and closed zones can be reported with the condition
BLK_ZONE_COND_ACTIVE in the case of a cached report zone.
However, the args pointer to a struct blk_report_zones_args that is
passed to disk_report_zones() can be NULL, e.g. in the case of internal
report zones operations for device mapper zoned targets.
Fix disk_report_zones() to make sure to check that the args is not null
before updating a zone condition for cached zone reports.
Fixes: 2284eec5053d ("block: introduce blkdev_get_zone_info()")
Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For zoned block devices that do not need zone write plugs (e.g. most
device mapper devices that support zones), the disk hash table of zone
write plugs is NULL. For such devices, blk_zone_reset_all_bio_endio()
should not attempt to scan this has table as that causes a NULL pointer
dereference.
Fix this by checking that the disk does have zone write plugs using the
atomic counter. This is equivalent to checking for a non-NULL hash table
but has the advantage to also speed up the execution of
blk_zone_reset_all_bio_endio() for devices that do use zone write plugs
but do not have any plug in the hash table (e.g. a disk with only full
zones).
Fixes: efae226c2e ("block: handle zone management operations completions")
Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the following code into the only caller of disk_zone_wplug_add_bio():
- The code for clearing the REQ_NOWAIT flag.
- The code that sets the BLK_ZONE_WPLUG_PLUGGED flag.
- The disk_zone_wplug_schedule_bio_work() call.
This patch moves all code that is related to REQ_NOWAIT or to bio
scheduling into a single function. Additionally, the 'schedule_bio_work'
variable is removed. No functionality has been changed.
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlmoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Document that all callers hold this lock because the code in
disk_zone_wplug_schedule_bio_work() depends on this.
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Remove a superfluous parenthesis that was introduced by commit fa8555630b
("blk-zoned: Improve the queue reference count strategy documentation").
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Introduce the function bdev_zone_start() as a more explicit (and clear)
replacement for ALIGN_DOWN() to get the start sector of a zone
containing a particular sector of a zoned block device.
Use this new helper in blkdev_get_zone_info() and
blkdev_report_zones_cached().
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The helper function blk_zone_wp_offset() is called from
disk_zone_wplug_sync_wp_offset(), and again called from
blk_revalidate_seq_zone() right after the call to
disk_zone_wplug_sync_wp_offset().
Change disk_zone_wplug_sync_wp_offset() to return the value of obtained
with blk_zone_wp_offset() to avoid this double call, which simplifies a
little blk_revalidate_seq_zone().
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_zone_wp_offset() is always called with a struct blk_zone obtained
from the device, that is, it will never see the BLK_ZONE_COND_ACTIVE
condition. However, handling this condition makes this function more
solid and will also avoid issues when propagating cached report requests
to underlying stacked devices is implemented. Add BLK_ZONE_COND_ACTIVE
as a new case in blk_zone_wp_offset() switch.
Also while at it, change the handling of the full condition to return
UINT_MAX for the zone write pointer to reflect the fact that the write
pointer of a full zone is invalid.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blkdev_do_report_zones returns the number of reported zones, but
blkdev_get_zone_info returns 0 or an errno. Translate to the expected
return value in blkdev_report_zone_fallback.
Fixes: b037d41762fd ("block: introduce blkdev_get_zone_info()")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No zone plugs are allocated when a zone is opened by calling Zone Append
on it. This makes the cached zone reporting report incorrectly empty
zones if the file system is unmounted and report zones is called after
that, e.g. by xfstests test cases using the scratch device.
Fix this by recording if zone append was used on a device, and disable
cached reporting for the device until a ZONE_RESET_ALL happens that
guarantees all zones are empty.
We could probably do even better using a per-zone flag, but the practical
use cache for zone reporting after the initial mount are rather limited,
so let's keep things simple for now.
Fixes: 31f0656a4a ("block: introduce blkdev_report_zones_cached()")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
disk->zones_cond is allocated for all zoned devices, but
disk_free_zone_resources skips it when the zone write plug hash is not
allocated, leaking the allocation for non-mq devices that don't emulate
zone append. This is reported by kmemleak-enabled xfstests for various
tests that use simple device mapper targets.
Fix this by moving all code that requires writes plugs from
disk_free_zone_resources into disk_destroy_zone_wplugs_hash_table
and executing the rest of the code, including the disk->zones_cond
freeing unconditionally.
Fixes: 6e945ffb65 ("block: use zone condition to determine conventional zones")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Modify queue_zone_wplug_show() to include the condition of a zone write
plug to the zone_wplugs debugfs attribute of a zoned block device.
To improve readability and ease of use, rather than the zone condition
raw value, the zone condition name is given using blk_zone_cond_str().
Suggested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Make the output of the zone_wplugs debugfs attribute file more easily
readable by adding the name of the zone write plugs fields in the
output.
No functional changes.
Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Introduce the new BLKREPORTZONESV2 ioctl command to allow user
applications access to the fast zone report implemented by
blkdev_report_zones_cached(). This new ioctl is defined as number 142
and is documented in include/uapi/linux/fs.h.
Unlike the existing BLKREPORTZONES ioctl, this new ioctl uses the flags
field of struct blk_zone_report also as an input. If the user sets the
BLK_ZONE_REP_CACHED flag as an input, then blkdev_report_zones_cached()
is used to generate the zone report using cached zone information. If
this flag is not set, then BLKREPORTZONESV2 behaves in the same manner
as BLKREPORTZONES and the zone report is generated by accessing the
zoned device.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Introduce the function blkdev_report_zones_cached() to provide a fast
report zone built using the blkdev_get_zone_info() function, which gets
zone information from a disk zones_cond array or zone write plugs.
For a large capacity SMR drive, such fast report zone can be completed
in a few milliseconds compared to several seconds completion times
when the report zone is obtained from the device.
The zone report is built in the same manner as with the regular
blkdev_report_zones() function, that is, the first zone reported is the
one containing the specified start sector and the report is limited to
the specified number of zones (nr_zones argument). The information for
each zone in the report is obtained using blkdev_get_zone_info().
For zoned devices that do not use zone write plug resources,
using blkdev_get_zone_info() is inefficient as the zone report would
be very slow, generated one zone at a time. To avoid this,
blkdev_report_zones_cached() falls back to calling
blkdev_do_report_zones() to execute a regular zone report. In this case,
the .report_active field of struct blk_report_zones_args is set to true
to report zone conditions using the BLK_ZONE_COND_ACTIVE condition in
place of the implicit open, explicit open and closed conditions.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Introduce the function blkdev_get_zone_info() to obtain a single zone
information from cached zone data, that is, either from the zone write
plug for the target zone if it exists and from the disk zones_cond
array otherwise.
Since sequential zones that do not have a zone write plug are either
full, empty or in a bad state (read-only or offline), the zone write
pointer can be inferred from the zone condition cached in the disk
zones_cond array. For sequential zones that have a zone write plug, the
zone condition and zone write pointer are obtained from the condition
and write pointer offset managed with the zone write plug. This allows
obtaining the information for a zone much more quickly than having to
execute a report zones command on the device.
blkdev_get_zone_info() falls back to using a regular zone report if the
target zone is flagged as needing an update with the
BLK_ZONE_WPLUG_NEED_WP_UPDATE flag, or if the target device does not
use zone write plugs (i.e. a device mapper device). In this case, the
new function blkdev_report_zone_fallback() is used and the zone
condition is reported consistantly with the cahced report, that is, the
BLK_ZONE_COND_ACTIVE condition is used in place of the implicit open,
explicit open and closed conditions. This is achieved by adding the
.report_active field to struct blk_report_zones_args and by having
disk_report_zone() sets the correct zone condition if .report_active is
true.
In preparation for using blkdev_get_zone_info() in upcoming file systems
changes, also export this function as a GPL symbol.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In preparation for implementing cached report zone, split the main part
of the code of blkdev_report_zones() into the helper function
blkdev_do_report_zones(), with this new helper taking as argument a
struct blk_report_zones_args pointer instead of a report callback
function and its private argument.
No functional changes.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The function blk_revalidate_zone_cond() already caches the condition of
all zones of a zoned block device in the zones_cond array of a gendisk.
However, the zone conditions are updated only when the device is scanned
or revalidated.
Implement tracking of the runtime changes to zone conditions using
the new cond field in struct blk_zone_wplug. The size of this structure
remains 112 Bytes as the new field replaces the 4 Bytes padding at the
end of the structure.
Beause zones that do not have a zone write plug can be in the empty,
implicit open, explicit open or full condition, the zones_cond array of
a disk is used to track the conditions, of zones that do not have a zone
write plug. The condition of such zone is updated in the disk zones_cond
array when a zone reset, reset all or finish operation is executed, and
also when a zone write plug is removed from the disk hash table when the
zone becomes full.
Since a device may automatically close an implicitly open zone when
writing to an empty or closed zone, if the total number of open zones
has reached the device limit, the BLK_ZONE_COND_IMP_OPEN and
BLK_ZONE_COND_CLOSED zone conditions cannot be precisely tracked. To
overcome this, the zone condition BLK_ZONE_COND_ACTIVE is introduced to
represent a zone that has the condition BLK_ZONE_COND_IMP_OPEN,
BLK_ZONE_COND_EXP_OPEN or BLK_ZONE_COND_CLOSED. This follows the
definition of an active zone as defined in the NVMe Zoned Namespace
specifications. As such, for a zoned device that has a limit on the
maximum number of open zones, we will never have more zones in the
BLK_ZONE_COND_ACTIVE condition than the device limit. This is compatible
with the SCSI ZBC and ATA ZAC specifications for SMR HDDs as these
devices do not have a limit on the number of active zones.
The function disk_zone_wplug_set_wp_offset() is modified to use the new
helper disk_zone_wplug_update_cond() to update a zone write plug
condition whenever a zone write plug write offset is updated on
submission or merging of write BIOs to a zone.
The functions blk_zone_reset_bio_endio(), blk_zone_reset_all_bio_endio()
and blk_zone_finish_bio_endio() are modified to update the condition of
the zones targeted by reset, reset_all and finish operations, either
using though disk_zone_wplug_set_wp_offset() for zones that have a
zone write plug, or using the disk_zone_set_cond() helper to update the
zones_cond array of the disk for zones that do not have a zone write
plug.
When a zone write plug is removed from the disk hash table (when the
zone becomes empty or full), the condition of struct blk_zone_wplug is
used to update the disk zones_cond array. Conversely, when a zone write
plug is added to the disk hash table, the zones_cond array is used to
initialize the zone write plug condition.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The conv_zones_bitmap field of struct gendisk is used to define a bitmap
to identify the conventional zones of a zoned block device. The bit for
a zone is set in this bitmap if the zone is a conventional one, that is,
if the zone type is BLK_ZONE_TYPE_CONVENTIONAL. For such zone, this
always corresponds to the zone condition BLK_ZONE_COND_NOT_WP.
In other words, conv_zones_bitmap tracks a single condition of the
zones of a zoned block device.
In preparation for tracking more zone conditions, change
conv_zones_bitmap into an array of zone conditions, using 1 byte per
zone. This increases the memory usage from 1 bit per zone to 1 byte per
zone, that is, from 16 KiB to about 100 KiB for a 30 TB SMR HDD with 256
MiB zones. This is a trade-off to allow fast cached report zones later
on top of this change.
Rename the conv_zones_bitmap field of struct gendisk to zones_cond. Add
a blk_revalidate_zone_cond() function to initialize the zones_cond array
of a disk during device scan and to update it on device revalidation.
Move the allocation of the zones_cond array to
disk_revalidate_zone_resources(), making sure that this array is always
allocated, even for devices that do not need zone write plugs (zone
resources), to ensure that bdev_zone_is_seq() can be re-implemented to
use the zone condition array in place of the conv zones bitmap.
Finally, the function bdev_zone_is_seq() is rewritten to use a test on
the condition of the target zone.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reorganize the fields of struct blk_zone_wplug to remove a hole after
the wp_offset field and avoid having the bio_work structure split
between 2 cache lines.
No functional changes.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit b76b840fd9 ("dm: Fix dm-zoned-reclaim zone write pointer
alignment") introduced an indirect call for the callback function of a
report zones executed with blkdev_report_zones(). This is necessary so
that the function disk_zone_wplug_sync_wp_offset() can be called to
refresh a zone write plug zone write pointer offset after a write error.
However, this solution makes following the path of a zone information
harder to understand.
Clean this up by introducing the new blk_report_zones_args structure to
define a zone report callback and its private data and introduce the
helper function disk_report_zone() which calls both
disk_zone_wplug_sync_wp_offset() and the zone report user callback
function for all zones of a zone report. This helper function must be
called by all block device drivers that implement the report zones
block operation in order to correctly report a zone information.
All block device drivers supporting the report_zones block operation are
updated to use this new scheme.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The variable capacity is used only in one place and so can be removed
and get_capacity(disk) used directly instead.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Modify disk_update_zone_resources() to freeze the device queue before
updating the number of zones, zone capacity and other zone related
resources. The locking order resulting from the call to
queue_limits_commit_update_frozen() is preserved, that is, the queue
limits lock is first taken by calling queue_limits_start_update() before
freezing the queue, and the queue is unfrozen after executing
queue_limits_commit_update(), which replaces the call to
queue_limits_commit_update_frozen().
This change ensures that there are no in-flights I/Os when the zone
resources are updated due to a zone revalidation. In case of error when
the limits are applied, directly call disk_free_zone_resources() from
disk_update_zone_resources() while the disk queue is still frozen to
avoid needing to freeze & unfreeze the queue again in
blk_revalidate_disk_zones(), thus simplifying that function code a
little.
Fixes: 0b83c86b44 ("block: Prevent potential deadlock in blk_revalidate_disk_zones()")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The functions blk_zone_wplug_handle_reset_or_finish() and
blk_zone_wplug_handle_reset_all() both modify the zone write pointer
offset of zone write plugs that are the target of a reset, reset all or
finish zone management operation. However, these functions do this
modification before the BIO is executed. So if the zone operation fails,
the modified zone write pointer offsets become invalid.
Avoid this by modifying the zone write pointer offset of a zone write
plug that is the target of a zone management operation when the
operation completes. To do so, modify blk_zone_bio_endio() to call the
new function blk_zone_mgmt_bio_endio() which in turn calls the functions
blk_zone_reset_all_bio_endio(), blk_zone_reset_bio_endio() or
blk_zone_finish_bio_endio() depending on the operation of the completed
BIO, to modify a zone write plug write pointer offset accordingly.
These functions are called only if the BIO execution was successful.
Fixes: dd291d77cc ("block: Introduce zone write plugging")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If preparing a write bio fails then blk_zone_wplug_bio_work() calls
bio_endio() with zwplug->lock held. If a device mapper driver is stacked
on top of the zoned block device then this results in nested locking of
zwplug->lock. The resulting lockdep complaint is a false positive
because this is nested locking and not recursive locking. Suppress this
false positive by calling blk_zone_wplug_bio_io_error() without holding
zwplug->lock. This is safe because no code in
blk_zone_wplug_bio_io_error() depends on zwplug->lock being held. This
patch suppresses the following lockdep complaint:
WARNING: possible recursive locking detected
--------------------------------------------
kworker/3:0H/46 is trying to acquire lock:
ffffff882968b830 (&zwplug->lock){-...}-{2:2}, at: blk_zone_write_plug_bio_endio+0x64/0x1f0
but task is already holding lock:
ffffff88315bc230 (&zwplug->lock){-...}-{2:2}, at: blk_zone_wplug_bio_work+0x8c/0x48c
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&zwplug->lock);
lock(&zwplug->lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by kworker/3:0H/46:
#0: ffffff8809486758 ((wq_completion)sdd_zwplugs){+.+.}-{0:0}, at: process_one_work+0x1bc/0x65c
#1: ffffffc085de3d70 ((work_completion)(&zwplug->bio_work)){+.+.}-{0:0}, at: process_one_work+0x1e4/0x65c
#2: ffffff88315bc230 (&zwplug->lock){-...}-{2:2}, at: blk_zone_wplug_bio_work+0x8c/0x48c
stack backtrace:
CPU: 3 UID: 0 PID: 46 Comm: kworker/3:0H Tainted: G W OE 6.12.38-android16-5-maybe-dirty-4k #1 8b362b6f76e3645a58cd27d86982bce10d150025
Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Spacecraft board based on MALIBU (DT)
Workqueue: sdd_zwplugs blk_zone_wplug_bio_work
Call trace:
dump_backtrace+0xfc/0x17c
show_stack+0x18/0x28
dump_stack_lvl+0x40/0xa0
dump_stack+0x18/0x24
print_deadlock_bug+0x38c/0x398
__lock_acquire+0x13e8/0x2e1c
lock_acquire+0x134/0x2b4
_raw_spin_lock_irqsave+0x5c/0x80
blk_zone_write_plug_bio_endio+0x64/0x1f0
bio_endio+0x9c/0x240
__dm_io_complete+0x214/0x260
clone_endio+0xe8/0x214
bio_endio+0x218/0x240
blk_zone_wplug_bio_work+0x204/0x48c
process_one_work+0x26c/0x65c
worker_thread+0x33c/0x498
kthread+0x110/0x134
ret_from_fork+0x10/0x20
Cc: stable@vger.kernel.org
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Fixes: dd291d77cc ("block: Introduce zone write plugging")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20250825182720.1697203-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a tracepoint for blkdev_zone_mgmt to trace zone management commands
submitted by higher layers like file systems or user space.
An example output for this tracepoint is as follows:
mkfs.btrfs-203 [001] ..... 42.877493: blkdev_zone_mgmt: 8,0 ZRS 5242880 + 0
This example output shows a REQ_OP_ZONE_RESET operation submitted by
mkfs.btrfs.
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250715115324.53308-5-johannes.thumshirn@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a tracepoint in blk_zone_update_request_bio() to trace the bio sector
update on ZONE APPEND completions.
An example for this tracepoint is as follows:
<idle>-0 [001] d.h1. 381.746444: blk_zone_update_request_bio: 259,5 ZAS 131072 () 1048832 + 256 none,0,0 [swapper/1]
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250715115324.53308-4-johannes.thumshirn@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_zone_update_request_bio() does two things. First it checks if the
request to be completed was written via ZONE APPEND and if yes it then
updates the sector to the one that the data was written to.
This is small enough to be an inline function. But upcoming changes adding
a tracepoint don't work if the function is inlined.
Split the function into two, the first is blk_req_bio_is_zone_append()
checking if the sector needs to be updated. This can still be an inline
function. The second is blk_zone_append_update_request_bio() doing the
sector update.
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250715115324.53308-3-johannes.thumshirn@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In preparation for fixing device mapper zone write handling, introduce
the inline helper function bio_needs_zone_write_plugging() to test if a
BIO requires handling through zone write plugging using the function
blk_zone_plug_bio(). This function returns true for any write
(op_is_write(bio) == true) operation directed at a zoned block device
using zone write plugging, that is, a block device with a disk that has
a zone write plug hash table.
This helper allows simplifying the check on entry to blk_zone_plug_bio()
and used in to protect calls to it for blk-mq devices and DM devices.
Fixes: f211268ed1 ("dm: Use the block layer zone append emulation")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250625093327.548866-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bios queued up in the zone write plug have already gone through all all
preparation in the submit_bio path, including the freeze protection.
Submitting them through submit_bio_noacct_nocheck duplicates the work
and can can cause deadlocks when freezing a queue with pending bio
write plugs.
Go straight to ->submit_bio or blk_mq_submit_bio to bypass the
superfluous extra freeze protection and checks.
Fixes: 9b1ce7f0c6 ("block: Implement zone append emulation")
Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20250611044416.2351850-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When blk_zone_write_plug_bio_endio() is called for a regular write BIO
used to emulate a zone append operation, that is, a BIO flagged with
BIO_EMULATES_ZONE_APPEND, the BIO operation code is restored to the
original REQ_OP_ZONE_APPEND but the BIO_EMULATES_ZONE_APPEND flag is not
cleared. Clear it to fully return the BIO to its orginal definition.
Fixes: 9b1ce7f0c6 ("block: Implement zone append emulation")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250611005915.89843-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
With the new large sector size support, it's now the case that
set_blocksize can change i_blksize and the folio order in a manner that
conflicts with a concurrent reader and causes a kernel crash.
Specifically, let's say that udev-worker calls libblkid to detect the
labels on a block device. The read call can create an order-0 folio to
read the first 4096 bytes from the disk. But then udev is preempted.
Next, someone tries to mount an 8k-sectorsize filesystem from the same
block device. The filesystem calls set_blksize, which sets i_blksize to
8192 and the minimum folio order to 1.
Now udev resumes, still holding the order-0 folio it allocated. It then
tries to schedule a read bio and do_mpage_readahead tries to create
bufferheads for the folio. Unfortunately, blocks_per_folio == 0 because
the page size is 4096 but the blocksize is 8192 so no bufferheads are
attached and the bh walk never sets bdev. We then submit the bio with a
NULL block device and crash.
Therefore, truncate the page cache after flushing but before updating
i_blksize. However, that's not enough -- we also need to lock out file
IO and page faults during the update. Take both the i_rwsem and the
invalidate_lock in exclusive mode for invalidations, and in shared mode
for read/write operations.
I don't know if this is the correct fix, but xfs/259 found it.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/174543795699.4139148.2086129139322431423.stgit@frogsfrogsfrogs
Signed-off-by: Jens Axboe <axboe@kernel.dk>
