Laptop mode was introduced to save battery, by delaying and consolidating
writes and thereby maximize the time rotating hard drives wouldn't have to
spin.
Luckily, rotating hard drives, with their high spin-up times and power
draw, are a thing of the past for battery-powered devices. Reclaim has
also since changed to not write single filesystem pages anymore, and
regular filesystem writeback is lumpy by design.
The juice doesn't appear worth the squeeze anymore. The footprint of the
feature is small, but nevertheless it's a complicating factor in mm,
block, filesystems. Developers don't think about it, and it likely hasn't
been tested with new reclaim and writeback changes in years.
Let's sunset it. Keep the sysctl with a deprecation warning around for a
few more cycles, but remove all functionality behind it.
[akpm@linux-foundation.org: fix Documentation/admin-guide/laptops/index.rst]
Link: https://lkml.kernel.org/r/20251216185201.GH905277@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Deepanshu Kartikey <kartikey406@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a third parameter 'const struct io_comp_batch *' to the rq_end_io_fn
callback signature. This allows end_io handlers to access the completion
batch context when requests are completed via blk_mq_end_request_batch().
The io_comp_batch is passed from blk_mq_end_request_batch(), while NULL
is passed from __blk_mq_end_request() and blk_mq_put_rq_ref() which don't
have batch context.
This infrastructure change enables drivers to detect whether they're
being called from a batched completion path (like iopoll) and access
additional context stored in the io_comp_batch.
Update all rq_end_io_fn implementations:
- block/blk-mq.c: blk_end_sync_rq
- block/blk-flush.c: flush_end_io, mq_flush_data_end_io
- drivers/nvme/host/ioctl.c: nvme_uring_cmd_end_io
- drivers/nvme/host/core.c: nvme_keep_alive_end_io
- drivers/nvme/host/pci.c: abort_endio, nvme_del_queue_end, nvme_del_cq_end
- drivers/nvme/target/passthru.c: nvmet_passthru_req_done
- drivers/scsi/scsi_error.c: eh_lock_door_done
- drivers/scsi/sg.c: sg_rq_end_io
- drivers/scsi/st.c: st_scsi_execute_end
- drivers/target/target_core_pscsi.c: pscsi_req_done
- drivers/md/dm-rq.c: end_clone_request
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
Pull block fixes from Jens Axboe:
- NVMe pull request via Keith:
- Device quirk to disable faulty temperature (Ilikara)
- TCP target null pointer fix from bad host protocol usage (Shivam)
- Add apple,t8103-nvme-ans2 as a compatible apple controller
(Janne)
- FC tagset leak fix (Chaitanya)
- TCP socket deadlock fix (Hannes)
- Target name buffer overrun fix (Shin'ichiro)
- Fix for an underflow for rnbd during device unmap
- Zero the non-PI part of the auto integrity buffer
- Fix for a configfs memory leak in the null block driver
* tag 'block-6.19-20260116' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
rnbd-clt: fix refcount underflow in device unmap path
nvme: fix PCIe subsystem reset controller state transition
nvmet: do not copy beyond sybsysnqn string length
nvmet-tcp: fixup hang in nvmet_tcp_listen_data_ready()
null_blk: fix kmemleak by releasing references to fault configfs items
block: zero non-PI portion of auto integrity buffer
nvme-fc: release admin tagset if init fails
nvme-apple: add "apple,t8103-nvme-ans2" as compatible
nvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec
nvme-pci: disable secondary temp for Wodposit WPBSNM8
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>
DMA IOVA state is not used inside blk_rq_dma_map_iter_next, get
rid of the argument.
Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge in fixes that went to 6.19 after for-7.0/block was branched.
Pending ublk changes depend on particularly the async scan work.
* block-6.19:
block: zero non-PI portion of auto integrity buffer
ublk: fix use-after-free in ublk_partition_scan_work
blk-mq: avoid stall during boot due to synchronize_rcu_expedited
loop: add missing bd_abort_claiming in loop_set_status
block: don't merge bios with different app_tags
blk-rq-qos: Remove unlikely() hints from QoS checks
loop: don't change loop device under exclusive opener in loop_set_status
block, bfq: update outdated comment
blk-mq: skip CPU offline notify on unmapped hctx
selftests/ublk: fix Makefile to rebuild on header changes
selftests/ublk: add test for async partition scan
ublk: scan partition in async way
block,bfq: fix aux stat accumulation destination
md: Fix forward incompatibility from configurable logical block size
md: Fix logical_block_size configuration being overwritten
md: suspend array while updating raid_disks via sysfs
md/raid5: fix possible null-pointer dereferences in raid5_store_group_thread_cnt()
md: Fix static checker warning in analyze_sbs
Add a blk_crypto_submit_bio helper that either submits the bio when
it is not encrypted or inline encryption is provided, but otherwise
handles the encryption before going down into the low-level driver.
This reduces the risk from bio reordering and keeps memory allocation
as high up in the stack as possible.
Note that if the submitter knows that inline enctryption is known to
be supported by the underyling driver, it can still use plain
submit_bio.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Avoid the relatively high overhead of constructing and walking per-page
segment bio_vecs for data unit alignment checking by merging the checks
into existing loops.
For hardware support crypto, perform the check in bio_split_io_at, which
already contains a similar alignment check applied for all I/O. This
means bio-based drivers that do not call bio_split_to_limits, should they
ever grow blk-crypto support, need to implement the check themselves,
just like all other queue limits checks.
For blk-crypto-fallback do it in the encryption/decryption loops. This
means alignment errors for decryption will only be detected after I/O
has completed, but that seems like a worthwhile trade off.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Calling mempool_alloc in a loop is not safe unless the maximum allocation
size times the maximum number of threads using it is less than the
minimum pool size. Use the new mempool_alloc_bulk helper to allocate
all missing elements in one pass to remove this deadlock risk. This
also means that non-pool allocations now use alloc_pages_bulk which can
be significantly faster than a loop over individual page allocations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Allocating a skcipher request dynamically can deadlock or cause
unexpected I/O failures when called from writeback context. Avoid the
allocation entirely by using on-stack skciphers, similar to what the
non-blk-crypto fscrypt path already does.
This drops the incomplete support for asynchronous algorithms, which
previously could be used, but only synchronously.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The current code in blk_crypto_fallback_encrypt_bio is inefficient and
prone to deadlocks under memory pressure: It first walks the passed in
plaintext bio to see how much of it can fit into a single encrypted
bio using up to BIO_MAX_VEC PAGE_SIZE segments, and then allocates a
plaintext clone that fits the size, only to allocate another bio for
the ciphertext later. While the plaintext clone uses a bioset to avoid
deadlocks when allocations could fail, the ciphertex one uses bio_kmalloc
which is a no-go in the file system I/O path.
Switch blk_crypto_fallback_encrypt_bio to walk the source plaintext bio
while consuming bi_iter without cloning it, and instead allocate a
ciphertext bio at the beginning and whenever we fille up the previous
one. The existing bio_set for the plaintext clones is reused for the
ciphertext bios to remove the deadlock risk.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Restructure blk_crypto_fallback_bio_prep so that it always submits the
encrypted bio instead of passing it back to the caller, which allows
to simplify the calling conventions for blk_crypto_fallback_bio_prep and
blk_crypto_bio_prep so that they never have to return a bio, and can
use a true return value to indicate that the caller should submit the
bio, and false that the blk-crypto code consumed it.
The submission is handled by the on-stack bio list in the current
task_struct by the block layer and does not cause additional stack
usage or major overhead. It also prepares for the following optimization
and fixes for the blk-crypto fallback write path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When checking if a bio fits in a single segment, bio_may_need_split()
compares bi_size against the current bvec's bv_len. However, for
partially consumed bvecs (bi_bvec_done > 0), such as in cloned or
split bios, the remaining bytes in the current bvec is actually
(bv_len - bi_bvec_done), not bv_len.
This could cause bio_may_need_split() to incorrectly return false,
leading to nr_phys_segments being set to 1 when the bio actually
spans multiple segments. This triggers the WARN_ON in __blk_rq_map_sg()
when the actual mapped segments exceed the expected count.
Fix by subtracting bi_bvec_done from bv_len in the comparison.
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Close: https://lore.kernel.org/linux-block/9687cf2b-1f32-44e1-b58d-2492dc6e7185@linux.ibm.com/
Repored-and-bisected-by: Christoph Hellwig <hch@infradead.org>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Tested-by: Christoph Hellwig <hch@infradead.org>
Fixes: ee623c892a ("block: use bvec iterator helper for bio_may_need_split()")
Cc: Nitesh Shetty <nj.shetty@samsung.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bi_offload_capable() returns whether a block device's metadata size
matches its PI tuple size. Use pi_tuple_size instead of switching on
csum_type. This makes the code considerably simpler and less branchy.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The auto-generated integrity buffer for writes needs to be fully
initialized before being passed to the underlying block device,
otherwise the uninitialized memory can be read back by userspace or
anyone with physical access to the storage device. If protection
information is generated, that portion of the integrity buffer is
already initialized. The integrity data is also zeroed if PI generation
is disabled via sysfs or the PI tuple size is 0. However, this misses
the case where PI is generated and the PI tuple size is nonzero, but the
metadata size is larger than the PI tuple. In this case, the remainder
("opaque") of the metadata is left uninitialized.
Generalize the BLK_INTEGRITY_CSUM_NONE check to cover any case when the
metadata is larger than just the PI tuple.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: c546d6f438 ("block: only zero non-PI metadata tuples in bio_integrity_prep")
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block fixes from Jens Axboe:
- Kill unlikely checks for blk-rq-qos. These checks are really
all-or-nothing, either the branch is taken all the time, or it's not.
Depending on the configuration, either one of those cases may be
true. Just remove the annotation
- Fix for merging bios with different app tags set
- Fix for a recently introduced slowdown due to RCU synchronization
- Fix for a status change on loop while it's in use, and then a later
fix for that fix
- Fix for the async partition scanning in ublk
* tag 'block-6.19-20260109' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
ublk: fix use-after-free in ublk_partition_scan_work
blk-mq: avoid stall during boot due to synchronize_rcu_expedited
loop: add missing bd_abort_claiming in loop_set_status
block: don't merge bios with different app_tags
blk-rq-qos: Remove unlikely() hints from QoS checks
loop: don't change loop device under exclusive opener in loop_set_status
bio_iov_bvec_set() creates a cloned bio that borrows a bvec array from
an iov_iter. For cloned bios, bi_vcnt is meaningless because iteration
is controlled entirely by bi_iter (bi_idx, bi_size, bi_bvec_done), not
by bi_vcnt. Remove the incorrect bi_vcnt assignment.
Explicitly initialize bi_iter.bi_idx to 0 to ensure iteration starts
at the first bvec. While bi_idx is typically already zero from bio
initialization, making this explicit improves clarity and correctness.
This change also avoids accessing iter->nr_segs, which is an iov_iter
implementation detail that block code should not depend on.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bio_may_need_split() uses bi_vcnt to determine if a bio has a single
segment, but bi_vcnt is unreliable for cloned bios. Cloned bios share
the parent's bi_io_vec array but iterate over a subset via bi_iter,
so bi_vcnt may not reflect the actual segment count being iterated.
Replace the bi_vcnt check with bvec iterator access via
__bvec_iter_bvec(), comparing bi_iter.bi_size against the current
bvec's length. This correctly handles both cloned and non-cloned bios.
Move bi_io_vec into the first cache line adjacent to bi_iter. This is
a sensible layout since bi_io_vec and bi_iter are commonly accessed
together throughout the block layer - every bvec iteration requires
both fields. This displaces bi_end_io to the second cache line, which
is acceptable since bi_end_io and bi_private are always fetched
together in bio_endio() anyway.
The struct layout change requires bio_reset() to preserve and restore
bi_io_vec across the memset, since it now falls within BIO_RESET_BYTES.
Nitesh verified that this patch doesn't regress NVMe 512-byte IO perf [1].
Link: https://lore.kernel.org/linux-block/20251220081607.tvnrltcngl3cc2fh@green245.gost/ [1]
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
nvme_set_app_tag() uses the app_tag value from the bio_integrity_payload
of the struct request's first bio. This assumes all the request's bios
have the same app_tag. However, it is possible for bios with different
app_tag values to be merged into a single request.
Add a check in blk_integrity_merge_{bio,rq}() to prevent the merging of
bios/requests with different app_tag values if BIP_CHECK_APPTAG is set.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: 3d8b5a22d4 ("block: add support to pass user meta buffer")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The unlikely() annotations on QUEUE_FLAG_QOS_ENABLED checks are
counterproductive. Writeback throttling (WBT) might be enabled by
default, mainly because CONFIG_BLK_WBT_MQ defaults to 'y'.
Branch profiling on Meta servers, which have WBT enabled, confirms 100%
misprediction rates on these checks.
Remove the unlikely() annotations to let the CPU's branch predictor
learn the actual behavior, potentially improving I/O path performance.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the struct phys_vec definition from block/blk-mq-dma.c to
include/linux/types.h to make it available for use across the kernel.
The phys_vec structure represents a physical address range with a
length, which is used by the new physical address-based DMA mapping
API. This structure is already used by the block layer and will be
needed for DMA phys API users.
Moving this definition to types.h provides a centralized location
for this common data structure and eliminates code duplication
across subsystems that need to work with physical address ranges.
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch changes the length variables from unsigned int to size_t.
Using size_t ensures that we can handle larger sizes, as size_t is
always equal to or larger than the previously used u32 type.
Originally, u32 was used because blk-mq-dma code evolved from
scatter-gather implementation, which uses unsigned int to describe length.
This change will also allow us to reuse the existing struct phys_vec in places
that don't need scatter-gather.
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block fixes from Jens Axboe:
- Scan partition tables asynchronously for ublk, similarly to how nvme
does it. This avoids potential deadlocks, which is why nvme does it
that way too. Includes a set of selftests as well.
- MD pull request via Yu:
- Fix null-pointer dereference in raid5 sysfs group_thread_cnt
store (Tuo Li)
- Fix possible mempool corruption during raid1 raid_disks update
via sysfs (FengWei Shih)
- Fix logical_block_size configuration being overwritten during
super_1_validate() (Li Nan)
- Fix forward incompatibility with configurable logical block size:
arrays assembled on new kernels could not be assembled on older
kernels (v6.18 and before) due to non-zero reserved pad rejection
(Li Nan)
- Fix static checker warning about iterator not incremented (Li Nan)
- Skip CPU offlining notifications on unmapped hardware queues
- bfq-iosched block stats fix
- Fix outdated comment in bfq-iosched
* tag 'block-6.19-20260102' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
block, bfq: update outdated comment
blk-mq: skip CPU offline notify on unmapped hctx
selftests/ublk: fix Makefile to rebuild on header changes
selftests/ublk: add test for async partition scan
ublk: scan partition in async way
block,bfq: fix aux stat accumulation destination
md: Fix forward incompatibility from configurable logical block size
md: Fix logical_block_size configuration being overwritten
md: suspend array while updating raid_disks via sysfs
md/raid5: fix possible null-pointer dereferences in raid5_store_group_thread_cnt()
md: Fix static checker warning in analyze_sbs
The function bfq_bfqq_may_idle() was renamed as bfq_better_to_idle()
in commit 277a4a9b56 ("block, bfq: give a better name to
bfq_bfqq_may_idle"). Update the comment accordingly.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If an hctx has no software ctx mapped, blk_mq_map_swqueue() never
allocates tags and leaves hctx->tags NULL. The CPU hotplug offline
notifier can still run for that hctx, return early since hctx cannot
hold any requests.
Signed-off-by: Cong Zhang <cong.zhang@oss.qualcomm.com>
Fixes: bf0beec060 ("blk-mq: drain I/O when all CPUs in a hctx are offline")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Route bfqg_stats_add_aux() time accumulation into the destination
stats object instead of the source, aligning with other stat fields.
Reviewed-by: Yu Kuai <yukuai@fnnas.com>
Signed-off-by: shechenglong <shechenglong@xfusion.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block fixes from Jens Axboe:
- ublk selftests for missing coverage
- two fixes for the block integrity code
- fix for the newly added newly added PR read keys ioctl, limiting the
memory that can be allocated
- work around for a deadlock that can occur with ublk, where partition
scanning ends up recursing back into file closure, which needs the
same mutex grabbed. Not the prettiest thing in the world, but an
acceptable work-around until we can eliminate the reliance on
disk->open_mutex for this
- fix for a race between enabling writeback throttling and new IO
submissions
- move a bit of bio flag handling code. No changes, but needed for a
patchset for a future kernel
- fix for an init time id leak failure in rnbd
- loop/zloop state check fix
* tag 'block-6.19-20251218' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
block: validate interval_exp integrity limit
block: validate pi_offset integrity limit
block: rnbd-clt: Fix leaked ID in init_dev()
ublk: fix deadlock when reading partition table
block: add allocation size check in blkdev_pr_read_keys()
Documentation: admin-guide: blockdev: replace zone_capacity with zone_capacity_mb when creating devices
zloop: use READ_ONCE() to read lo->lo_state in queue_rq path
loop: use READ_ONCE() to read lo->lo_state without locking
block: fix race between wbt_enable_default and IO submission
selftests: ublk: add user copy test cases
selftests: ublk: add support for user copy to kublk
selftests: ublk: forbid multiple data copy modes
selftests: ublk: don't share backing files between ublk servers
selftests: ublk: use auto_zc for PER_IO_DAEMON tests in stress_04
selftests: ublk: fix fio arguments in run_io_and_recover()
selftests: ublk: remove unused ios map in seq_io.bt
selftests: ublk: correct last_rw map type in seq_io.bt
selftests: ublk: fix overflow in ublk_queue_auto_zc_fallback()
block: move around bio flagging helpers
Various code assumes that the integrity interval is at least 1 sector
and evenly divides the logical block size. Add these checks to
blk_validate_integrity_limits(). This guards against block drivers that
report invalid interval_exp values.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The PI tuple must be contained within the metadata value, so validate
that pi_offset + pi_tuple_size <= metadata_size. This guards against
block drivers that report invalid pi_offset values.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When wbt_enable_default() is moved out of queue freezing in elevator_change(),
it can cause the wbt inflight counter to become negative (-1), leading to hung
tasks in the writeback path. Tasks get stuck in wbt_wait() because the counter
is in an inconsistent state.
The issue occurs because wbt_enable_default() could race with IO submission,
allowing the counter to be decremented before proper initialization. This manifests
as:
rq_wait[0]:
inflight: -1
has_waiters: True
rwb_enabled() checks the state, which can be updated exactly between wbt_wait()
(rq_qos_throttle()) and wbt_track()(rq_qos_track()), then the inflight counter
will become negative.
And results in hung task warnings like:
task:kworker/u24:39 state:D stack:0 pid:14767
Call Trace:
rq_qos_wait+0xb4/0x150
wbt_wait+0xa9/0x100
__rq_qos_throttle+0x24/0x40
blk_mq_submit_bio+0x672/0x7b0
...
Fix this by:
1. Splitting wbt_enable_default() into:
- __wbt_enable_default(): Returns true if wbt_init() should be called
- wbt_enable_default(): Wrapper for existing callers (no init)
- wbt_init_enable_default(): New function that checks and inits WBT
2. Using wbt_init_enable_default() in blk_register_queue() to ensure
proper initialization during queue registration
3. Move wbt_init() out of wbt_enable_default() which is only for enabling
disabled wbt from bfq and iocost, and wbt_init() isn't needed. Then the
original lock warning can be avoided.
4. Removing the ELEVATOR_FLAG_ENABLE_WBT_ON_EXIT flag and its handling
code since it's no longer needed
This ensures WBT is properly initialized before any IO can be submitted,
preventing the counter from going negative.
Cc: Nilay Shroff <nilay@linux.ibm.com>
Cc: Yu Kuai <yukuai@fnnas.com>
Cc: Guangwu Zhang <guazhang@redhat.com>
Fixes: 78c271344b ("block: move wbt_enable_default() out of queue freezing from sched ->exit()")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block fixes from Jens Axboe:
- Always initialize DMA state, fixing a potentially nasty issue on the
block side
- btrfs zoned write fix with cached zone reports
- Fix corruption issues in bcache with chained bio's, and further make
it clear that the chained IO handler is simply a marker, it's not
code meant to be executed
- Kill old code dealing with synchronous IO polling in the block layer,
that has been dead for a long time. Only async polling is supported
these days
- Fix a lockdep issue in tag_set management, moving it to RCU
- Fix an issue with ublks bio_vec iteration
- Don't unconditionally enforce blocking issue of ublk control
commands, allow some of them with non-blocking issue as they
do not block
* tag 'block-6.19-20251211' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
blk-mq-dma: always initialize dma state
blk-mq: delete task running check in blk_hctx_poll()
block: fix cached zone reports on devices with native zone append
block: Use RCU in blk_mq_[un]quiesce_tagset() instead of set->tag_list_lock
ublk: don't mutate struct bio_vec in iteration
block: prohibit calls to bio_chain_endio
bcache: fix improper use of bi_end_io
ublk: allow non-blocking ctrl cmds in IO_URING_F_NONBLOCK issue
Ensure the dma state is initialized when we're not using the contiguous
iova, otherwise the caller may be using a stale state from a previous
request that could use the coalesed iova allocation.
Fixes: 2f6b2565d4 ("block: accumulate memory segment gaps per bio")
Reported-by: Sebastian Ott <sebott@redhat.com>
Tested-by: Sebastian Ott <sebott@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_hctx_poll() always checks if the task is running or not, and returns
1 if the task is running. This is a leftover from when polled IO was
purely for synchronous IO, and doesn't make sense anymore when polled IO
is purely asynchronous. Similarly, marking the task as TASK_RUNNING is
also superflous, as the very much has to be running to enter the
function in the first place.
It looks like there has been this judgment for historical reasons, and
in very early versions of this function the user would set the process
state to TASK_UNINTERRUPTIBLE.
Signed-off-by: Diangang Li <lidiangang@bytedance.com>
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
[axboe: kill all remnants of task running, pointless now. massage message]
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>
blk_mq_{add,del}_queue_tag_set() functions add and remove queues from
tagset, the functions make sure that tagset and queues are marked as
shared when two or more queues are attached to the same tagset.
Initially a tagset starts as unshared and when the number of added
queues reaches two, blk_mq_add_queue_tag_set() marks it as shared along
with all the queues attached to it. When the number of attached queues
drops to 1 blk_mq_del_queue_tag_set() need to mark both the tagset and
the remaining queues as unshared.
Both functions need to freeze current queues in tagset before setting on
unsetting BLK_MQ_F_TAG_QUEUE_SHARED flag. While doing so, both functions
hold set->tag_list_lock mutex, which makes sense as we do not want
queues to be added or deleted in the process. This used to work fine
until commit 98d81f0df7 ("nvme: use blk_mq_[un]quiesce_tagset")
made the nvme driver quiesce tagset instead of quiscing individual
queues. blk_mq_quiesce_tagset() does the job and quiesce the queues in
set->tag_list while holding set->tag_list_lock also.
This results in deadlock between two threads with these stacktraces:
__schedule+0x47c/0xbb0
? timerqueue_add+0x66/0xb0
schedule+0x1c/0xa0
schedule_preempt_disabled+0xa/0x10
__mutex_lock.constprop.0+0x271/0x600
blk_mq_quiesce_tagset+0x25/0xc0
nvme_dev_disable+0x9c/0x250
nvme_timeout+0x1fc/0x520
blk_mq_handle_expired+0x5c/0x90
bt_iter+0x7e/0x90
blk_mq_queue_tag_busy_iter+0x27e/0x550
? __blk_mq_complete_request_remote+0x10/0x10
? __blk_mq_complete_request_remote+0x10/0x10
? __call_rcu_common.constprop.0+0x1c0/0x210
blk_mq_timeout_work+0x12d/0x170
process_one_work+0x12e/0x2d0
worker_thread+0x288/0x3a0
? rescuer_thread+0x480/0x480
kthread+0xb8/0xe0
? kthread_park+0x80/0x80
ret_from_fork+0x2d/0x50
? kthread_park+0x80/0x80
ret_from_fork_asm+0x11/0x20
__schedule+0x47c/0xbb0
? xas_find+0x161/0x1a0
schedule+0x1c/0xa0
blk_mq_freeze_queue_wait+0x3d/0x70
? destroy_sched_domains_rcu+0x30/0x30
blk_mq_update_tag_set_shared+0x44/0x80
blk_mq_exit_queue+0x141/0x150
del_gendisk+0x25a/0x2d0
nvme_ns_remove+0xc9/0x170
nvme_remove_namespaces+0xc7/0x100
nvme_remove+0x62/0x150
pci_device_remove+0x23/0x60
device_release_driver_internal+0x159/0x200
unbind_store+0x99/0xa0
kernfs_fop_write_iter+0x112/0x1e0
vfs_write+0x2b1/0x3d0
ksys_write+0x4e/0xb0
do_syscall_64+0x5b/0x160
entry_SYSCALL_64_after_hwframe+0x4b/0x53
The top stacktrace is showing nvme_timeout() called to handle nvme
command timeout. timeout handler is trying to disable the controller and
as a first step, it needs to blk_mq_quiesce_tagset() to tell blk-mq not
to call queue callback handlers. The thread is stuck waiting for
set->tag_list_lock as it tries to walk the queues in set->tag_list.
The lock is held by the second thread in the bottom stack which is
waiting for one of queues to be frozen. The queue usage counter will
drop to zero after nvme_timeout() finishes, and this will not happen
because the thread will wait for this mutex forever.
Given that [un]quiescing queue is an operation that does not need to
sleep, update blk_mq_[un]quiesce_tagset() to use RCU instead of taking
set->tag_list_lock, update blk_mq_{add,del}_queue_tag_set() to use RCU
safe list operations. Also, delete INIT_LIST_HEAD(&q->tag_set_list)
in blk_mq_del_queue_tag_set() because we can not re-initialize it while
the list is being traversed under RCU. The deleted queue will not be
added/deleted to/from a tagset and it will be freed in blk_free_queue()
after the end of RCU grace period.
Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
Fixes: 98d81f0df7 ("nvme: use blk_mq_[un]quiesce_tagset")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that all potential callers of bio_chain_endio have been
eliminated, completely prohibit any future calls to this function.
Suggested-by: Ming Lei <ming.lei@redhat.com>
Suggested-by: Andreas Gruenbacher <agruenba@redhat.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shida Zhang <zhangshida@kylinos.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block updates from Jens Axboe:
"Followup set of fixes and updates for block for the 6.19 merge window.
NVMe had some late minute debates which lead to dropping some patches
from that tree, which is why the initial PR didn't have NVMe included.
It's here now. This pull request contains:
- NVMe pull request via Keith:
- Subsystem usage cleanups (Max)
- Endpoint device fixes (Shin'ichiro)
- Debug statements (Gerd)
- FC fabrics cleanups and fixes (Daniel)
- Consistent alloc API usages (Israel)
- Code comment updates (Chu)
- Authentication retry fix (Justin)
- Fix a memory leak in the discard ioctl code, if the task is being
interrupted by a signal at just the wrong time
- Zoned write plugging fixes
- Add ioctls for for persistent reservations
- Enable per-cpu bio caching by default
- Various little fixes and tweaks"
* tag 'block-6.19-20251208' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (27 commits)
nvme-fabrics: add ENOKEY to no retry criteria for authentication failures
nvme-auth: use kvfree() for memory allocated with kvcalloc()
nvmet-tcp: use kvcalloc for commands array
nvmet-rdma: use kvcalloc for commands and responses arrays
nvme: fix typo error in nvme target
nvmet-fc: use pr_* print macros instead of dev_*
nvmet-fcloop: remove unused lsdir member.
nvmet-fcloop: check all request and response have been processed
nvme-fc: check all request and response have been processed
block: fix memory leak in __blkdev_issue_zero_pages
block: fix comment for op_is_zone_mgmt() to include RESET_ALL
block: Clear BLK_ZONE_WPLUG_PLUGGED when aborting plugged BIOs
blk-mq: Abort suspend when wakeup events are pending
blk-mq: add blk_rq_nr_bvec() helper
block: add IOC_PR_READ_RESERVATION ioctl
block: add IOC_PR_READ_KEYS ioctl
nvme: reject invalid pr_read_keys() num_keys values
scsi: sd: reject invalid pr_read_keys() num_keys values
block: enable per-cpu bio cache by default
block: use bio_alloc_bioset for passthru IO by default
...
Pull VFIO updates from Alex Williamson:
- Move libvfio selftest artifacts in preparation of more tightly
coupled integration with KVM selftests (David Matlack)
- Fix comment typo in mtty driver (Chu Guangqing)
- Support for new hardware revision in the hisi_acc vfio-pci variant
driver where the migration registers can now be accessed via the PF.
When enabled for this support, the full BAR can be exposed to the
user (Longfang Liu)
- Fix vfio cdev support for VF token passing, using the correct size
for the kernel structure, thereby actually allowing userspace to
provide a non-zero UUID token. Also set the match token callback for
the hisi_acc, fixing VF token support for this this vfio-pci variant
driver (Raghavendra Rao Ananta)
- Introduce internal callbacks on vfio devices to simplify and
consolidate duplicate code for generating VFIO_DEVICE_GET_REGION_INFO
data, removing various ioctl intercepts with a more structured
solution (Jason Gunthorpe)
- Introduce dma-buf support for vfio-pci devices, allowing MMIO regions
to be exposed through dma-buf objects with lifecycle managed through
move operations. This enables low-level interactions such as a
vfio-pci based SPDK drivers interacting directly with dma-buf capable
RDMA devices to enable peer-to-peer operations. IOMMUFD is also now
able to build upon this support to fill a long standing feature gap
versus the legacy vfio type1 IOMMU backend with an implementation of
P2P support for VM use cases that better manages the lifecycle of the
P2P mapping (Leon Romanovsky, Jason Gunthorpe, Vivek Kasireddy)
- Convert eventfd triggering for error and request signals to use RCU
mechanisms in order to avoid a 3-way lockdep reported deadlock issue
(Alex Williamson)
- Fix a 32-bit overflow introduced via dma-buf support manifesting with
large DMA buffers (Alex Mastro)
- Convert nvgrace-gpu vfio-pci variant driver to insert mappings on
fault rather than at mmap time. This conversion serves both to make
use of huge PFNMAPs but also to both avoid corrected RAS events
during reset by now being subject to vfio-pci-core's use of
unmap_mapping_range(), and to enable a device readiness test after
reset (Ankit Agrawal)
- Refactoring of vfio selftests to support multi-device tests and split
code to provide better separation between IOMMU and device objects.
This work also enables a new test suite addition to measure parallel
device initialization latency (David Matlack)
* tag 'vfio-v6.19-rc1' of https://github.com/awilliam/linux-vfio: (65 commits)
vfio: selftests: Add vfio_pci_device_init_perf_test
vfio: selftests: Eliminate INVALID_IOVA
vfio: selftests: Split libvfio.h into separate header files
vfio: selftests: Move vfio_selftests_*() helpers into libvfio.c
vfio: selftests: Rename vfio_util.h to libvfio.h
vfio: selftests: Stop passing device for IOMMU operations
vfio: selftests: Move IOVA allocator into iova_allocator.c
vfio: selftests: Move IOMMU library code into iommu.c
vfio: selftests: Rename struct vfio_dma_region to dma_region
vfio: selftests: Upgrade driver logging to dev_err()
vfio: selftests: Prefix logs with device BDF where relevant
vfio: selftests: Eliminate overly chatty logging
vfio: selftests: Support multiple devices in the same container/iommufd
vfio: selftests: Introduce struct iommu
vfio: selftests: Rename struct vfio_iommu_mode to iommu_mode
vfio: selftests: Allow passing multiple BDFs on the command line
vfio: selftests: Split run.sh into separate scripts
vfio: selftests: Move run.sh into scripts directory
vfio/nvgrace-gpu: wait for the GPU mem to be ready
vfio/nvgrace-gpu: Inform devmem unmapped after reset
...
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>
During system suspend, wakeup capable IRQs for block device can be
delayed, which can cause blk_mq_hctx_notify_offline() to hang
indefinitely while waiting for pending request to complete.
Skip the request waiting loop and abort suspend when wakeup events are
pending to prevent the deadlock.
Fixes: bf0beec060 ("blk-mq: drain I/O when all CPUs in a hctx are offline")
Signed-off-by: Cong Zhang <cong.zhang@oss.qualcomm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a Persistent Reservations ioctl to read the current reservation.
This calls the pr_ops->read_reservation() function that was previously
added in commit c787f1baa5 ("block: Add PR callouts for read keys and
reservation") but was only used by the in-kernel SCSI target so far.
The IOC_PR_READ_RESERVATION ioctl is necessary so that userspace
applications that rely on Persistent Reservations ioctls have a way of
inspecting the current state. Cluster managers and validation tests need
this functionality.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a Persistent Reservations ioctl to read the list of currently
registered reservation keys. This calls the pr_ops->read_keys() function
that was previously added in commit c787f1baa5 ("block: Add PR
callouts for read keys and reservation") but was only used by the
in-kernel SCSI target so far.
The IOC_PR_READ_KEYS ioctl is necessary so that userspace applications
that rely on Persistent Reservations ioctls have a way of inspecting the
current state. Cluster managers and validation tests need this
functionality.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since after commit 12e4e8c7ab ("io_uring/rw: enable bio caches for
IRQ rw"), bio_put is safe for task and irq context, bio_alloc_bioset is
safe for task context and no one calls in irq context, so we can enable
per cpu bio cache by default.
Benchmarked with t/io_uring and ext4+nvme:
taskset -c 6 /root/fio/t/io_uring -p0 -d128 -b4096 -s1 -c1 -F1 -B1 -R1
-X1 -n1 -P1 /mnt/testfile
base IOPS is 562K, patch IOPS is 574K. The CPU usage of bio_alloc_bioset
decrease from 1.42% to 1.22%.
The worst case is allocate bio in CPU A but free in CPU B, still use
t/io_uring and ext4+nvme:
base IOPS is 648K, patch IOPS is 647K.
Also use fio test ext4/xfs with libaio/sync/io_uring on null_blk and
nvme, no obvious performance regression.
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use bio_alloc_bioset for passthru IO by default, so that we can enable
bio cache for irq and polled passthru IO in later.
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
