Commit Graph

8101 Commits

Author SHA1 Message Date
Jens Axboe
5df832ba5f Merge branch 'block-6.19' into for-7.0/block
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  block, bfq: update outdated comment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
2026-01-11 13:16:36 -07:00
Christoph Hellwig
bb8e2019ad blk-crypto: handle the fallback above the block layer
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>
2026-01-11 12:55:41 -07:00
Christoph Hellwig
66e5a11d2e blk-crypto: optimize data unit alignment checking
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>
2026-01-11 12:55:41 -07:00
Christoph Hellwig
3d939695e6 blk-crypto: use mempool_alloc_bulk for encrypted bio page allocation
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>
2026-01-11 12:55:41 -07:00
Christoph Hellwig
2f655dcb2d blk-crypto: use on-stack skcipher requests for fallback en/decryption
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>
2026-01-11 12:55:41 -07:00
Christoph Hellwig
b37fbce460 blk-crypto: optimize bio splitting in blk_crypto_fallback_encrypt_bio
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>
2026-01-11 12:55:41 -07:00
Christoph Hellwig
aefc2a1fa2 blk-crypto: submit the encrypted bio in blk_crypto_fallback_bio_prep
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>
2026-01-11 12:55:41 -07:00
Ming Lei
f7ba87dfa8 block: account for bi_bvec_done in bio_may_need_split()
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>
2026-01-10 10:22:54 -07:00
Caleb Sander Mateos
a31bde687b block: use pi_tuple_size in bi_offload_capable()
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>
2026-01-10 10:22:54 -07:00
Caleb Sander Mateos
ca22c566b8 block: zero non-PI portion of auto integrity buffer
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>
2026-01-10 10:22:07 -07:00
Mikulas Patocka
9670db22e7 blk-mq: avoid stall during boot due to synchronize_rcu_expedited
On the kernel 6.19-rc, I am experiencing 15-second boot stall in a
virtual machine when probing a virtio-scsi disk:
[    1.011641] SCSI subsystem initialized
[    1.013972] virtio_scsi virtio6: 16/0/0 default/read/poll queues
[    1.015983] scsi host0: Virtio SCSI HBA
[    1.019578] ACPI: \_SB_.GSIA: Enabled at IRQ 16
[    1.020225] ahci 0000:00:1f.2: AHCI vers 0001.0000, 32 command slots, 1.5 Gbps, SATA mode
[    1.020228] ahci 0000:00:1f.2: 6/6 ports implemented (port mask 0x3f)
[    1.020230] ahci 0000:00:1f.2: flags: 64bit ncq only
[    1.024688] scsi host1: ahci
[    1.025432] scsi host2: ahci
[    1.025966] scsi host3: ahci
[    1.026511] scsi host4: ahci
[    1.028371] scsi host5: ahci
[    1.028918] scsi host6: ahci
[    1.029266] ata1: SATA max UDMA/133 abar m4096@0xfea23000 port 0xfea23100 irq 16 lpm-pol 1
[    1.029305] ata2: SATA max UDMA/133 abar m4096@0xfea23000 port 0xfea23180 irq 16 lpm-pol 1
[    1.029316] ata3: SATA max UDMA/133 abar m4096@0xfea23000 port 0xfea23200 irq 16 lpm-pol 1
[    1.029327] ata4: SATA max UDMA/133 abar m4096@0xfea23000 port 0xfea23280 irq 16 lpm-pol 1
[    1.029341] ata5: SATA max UDMA/133 abar m4096@0xfea23000 port 0xfea23300 irq 16 lpm-pol 1
[    1.029356] ata6: SATA max UDMA/133 abar m4096@0xfea23000 port 0xfea23380 irq 16 lpm-pol 1
[    1.118111] scsi 0:0:0:0: Direct-Access     QEMU     QEMU HARDDISK 2.5+ PQ: 0 ANSI: 5
[    1.348916] ata1: SATA link down (SStatus 0 SControl 300)
[    1.350713] ata2: SATA link down (SStatus 0 SControl 300)
[    1.351025] ata6: SATA link down (SStatus 0 SControl 300)
[    1.351160] ata5: SATA link down (SStatus 0 SControl 300)
[    1.351326] ata3: SATA link down (SStatus 0 SControl 300)
[    1.351536] ata4: SATA link down (SStatus 0 SControl 300)
[    1.449153] input: ImExPS/2 Generic Explorer Mouse as /devices/platform/i8042/serio1/input/input2
[   16.483477] sd 0:0:0:0: Power-on or device reset occurred
[   16.483691] sd 0:0:0:0: [sda] 2097152 512-byte logical blocks: (1.07 GB/1.00 GiB)
[   16.483762] sd 0:0:0:0: [sda] Write Protect is off
[   16.483877] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[   16.569225] sd 0:0:0:0: [sda] Attached SCSI disk

I bisected it and it is caused by the commit 89e1fb7cef which
introduces calls to synchronize_rcu_expedited.

This commit replaces synchronize_rcu_expedited and kfree with a call to
kfree_rcu_mightsleep, avoiding the 15-second delay.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 89e1fb7cef ("blk-mq: fix potential uaf for 'queue_hw_ctx'")
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-07 08:10:42 -07:00
Ming Lei
6418643148 block: don't initialize bi_vcnt for cloned bio in bio_iov_bvec_set()
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>
2026-01-07 08:06:33 -07:00
Ming Lei
ee623c892a block: use bvec iterator helper for bio_may_need_split()
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>
2026-01-07 08:06:33 -07:00
Caleb Sander Mateos
6acd4ac5f8 block: don't merge bios with different app_tags
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>
2026-01-06 19:10:08 -07:00
Breno Leitao
7d121d701d blk-rq-qos: Remove unlikely() hints from QoS checks
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>
2026-01-06 19:08:23 -07:00
Julia Lawall
69153e8b97 block, bfq: update outdated comment
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>
2026-01-01 08:57:37 -07:00
Cong Zhang
10845a105b blk-mq: skip CPU offline notify on unmapped hctx
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>
2025-12-30 09:02:22 -07:00
shechenglong
04bdb1a04d block,bfq: fix aux stat accumulation destination
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>
2025-12-28 09:03:51 -07:00
Linus Torvalds
d8ba32c5a4 Merge tag 'block-6.19-20251218' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
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
2025-12-20 09:48:56 -08:00
Caleb Sander Mateos
af65faf34f block: validate interval_exp integrity limit
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>
2025-12-18 09:51:49 -07:00
Caleb Sander Mateos
ccb8a3c08a block: validate pi_offset integrity limit
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>
2025-12-18 09:51:49 -07:00
Deepanshu Kartikey
a58383fa45 block: add allocation size check in blkdev_pr_read_keys()
blkdev_pr_read_keys() takes num_keys from userspace and uses it to
calculate the allocation size for keys_info via struct_size(). While
there is a check for SIZE_MAX (integer overflow), there is no upper
bound validation on the allocation size itself.

A malicious or buggy userspace can pass a large num_keys value that
doesn't trigger overflow but still results in an excessive allocation
attempt, causing a warning in the page allocator when the order exceeds
MAX_PAGE_ORDER.

Fix this by introducing PR_KEYS_MAX to limit the number of keys to
a sane value. This makes the SIZE_MAX check redundant, so remove it.
Also switch to kvzalloc/kvfree to handle larger allocations gracefully.

Fixes: 22a1ffea5f ("block: add IOC_PR_READ_KEYS ioctl")
Tested-by: syzbot+660d079d90f8a1baf54d@syzkaller.appspotmail.com
Reported-by: syzbot+660d079d90f8a1baf54d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=660d079d90f8a1baf54d
Link: https://lore.kernel.org/all/20251212013510.3576091-1-kartikey406@gmail.com/T/ [v1]
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-12-17 07:35:22 -07:00
Ming Lei
9869d3a6fe block: fix race between wbt_enable_default and IO submission
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>
2025-12-12 12:51:11 -07:00
Linus Torvalds
35ebee7e72 Merge tag 'block-6.19-20251211' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
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
2025-12-12 22:04:18 +12:00
Keith Busch
a0750fae73 blk-mq-dma: always initialize dma state
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>
2025-12-10 13:41:11 -07:00
Fengnan Chang
f22ecf9c14 blk-mq: delete task running check in blk_hctx_poll()
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>
2025-12-10 02:40:52 -07:00
Johannes Thumshirn
2c38ec934d block: fix cached zone reports on devices with native zone append
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>
2025-12-09 22:35:54 -07:00
Mohamed Khalfella
59e25ef2b4 block: Use RCU in blk_mq_[un]quiesce_tagset() instead of set->tag_list_lock
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>
2025-12-09 10:24:55 -07:00
Shida Zhang
cfdeb588ae block: prohibit calls to bio_chain_endio
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>
2025-12-09 10:20:03 -07:00
Linus Torvalds
4482ebb297 Merge tag 'block-6.19-20251208' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
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
  ...
2025-12-09 08:53:24 +09:00
Linus Torvalds
a3ebb59eee Merge tag 'vfio-v6.19-rc1' of https://github.com/awilliam/linux-vfio
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
  ...
2025-12-04 18:42:48 -08:00
Shaurya Rane
f7e3f852a4 block: fix memory leak in __blkdev_issue_zero_pages
Move the fatal signal check before bio_alloc() to prevent a memory
leak when BLKDEV_ZERO_KILLABLE is set and a fatal signal is pending.

Previously, the bio was allocated before checking for a fatal signal.
If a signal was pending, the code would break out of the loop without
freeing or chaining the just-allocated bio, causing a memory leak.

This matches the pattern already used in __blkdev_issue_write_zeroes()
where the signal check precedes the allocation.

Fixes: bf86bcdb40 ("blk-lib: check for kill signal in ioctl BLKZEROOUT")
Reported-by: syzbot+527a7e48a3d3d315d862@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=527a7e48a3d3d315d862
Signed-off-by: Shaurya Rane <ssrane_b23@ee.vjti.ac.in>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Tested-by: syzbot+527a7e48a3d3d315d862@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-12-04 15:43:28 -07:00
Damien Le Moal
552c1149af block: Clear BLK_ZONE_WPLUG_PLUGGED when aborting plugged BIOs
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>
2025-12-04 15:43:28 -07:00
Cong Zhang
c196bf43d7 blk-mq: Abort suspend when wakeup events are pending
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>
2025-12-04 07:19:26 -07:00
Stefan Hajnoczi
3e2cb9ee76 block: add IOC_PR_READ_RESERVATION ioctl
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>
2025-12-04 07:19:26 -07:00
Stefan Hajnoczi
22a1ffea5f block: add IOC_PR_READ_KEYS ioctl
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>
2025-12-04 07:19:26 -07:00
Fengnan Chang
48f22f8093 block: enable per-cpu bio cache by default
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>
2025-12-04 07:19:24 -07:00
Fengnan Chang
05ce4c584c block: use bio_alloc_bioset for passthru IO by default
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>
2025-12-04 07:18:54 -07:00
Linus Torvalds
cc25df3e2e Merge tag 'for-6.19/block-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull block updates from Jens Axboe:

 - Fix head insertion for mq-deadline, a regression from when priority
   support was added

 - Series simplifying and improving the ublk user copy code

 - Various ublk related cleanups

 - Fixup REQ_NOWAIT handling in loop/zloop, clearing NOWAIT when the
   request is punted to a thread for handling

 - Merge and then later revert loop dio nowait support, as it ended up
   causing excessive stack usage for when the inline issue code needs to
   dip back into the full file system code

 - Improve auto integrity code, making it less deadlock prone

 - Speedup polled IO handling, but manually managing the hctx lookups

 - Fixes for blk-throttle for SSD devices

 - Small series with fixes for the S390 dasd driver

 - Add support for caching zones, avoiding unnecessary report zone
   queries

 - MD pull requests via Yu:
      - fix null-ptr-dereference regression for dm-raid0
      - fix IO hang for raid5 when array is broken with IO inflight
      - remove legacy 1s delay to speed up system shutdown
      - change maintainer's email address
      - data can be lost if array is created with different lbs devices,
        fix this problem and record lbs of the array in metadata
      - fix rcu protection for md_thread
      - fix mddev kobject lifetime regression
      - enable atomic writes for md-linear
      - some cleanups

 - bcache updates via Coly
      - remove useless discard and cache device code
      - improve usage of per-cpu workqueues

 - Reorganize the IO scheduler switching code, fixing some lockdep
   reports as well

 - Improve the block layer P2P DMA support

 - Add support to the block tracing code for zoned devices

 - Segment calculation improves, and memory alignment flexibility
   improvements

 - Set of prep and cleanups patches for ublk batching support. The
   actual batching hasn't been added yet, but helps shrink down the
   workload of getting that patchset ready for 6.20

 - Fix for how the ps3 block driver handles segments offsets

 - Improve how block plugging handles batch tag allocations

 - nbd fixes for use-after-free of the configuration on device clear/put

 - Set of improvements and fixes for zloop

 - Add Damien as maintainer of the block zoned device code handling

 - Various other fixes and cleanups

* tag 'for-6.19/block-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (162 commits)
  block/rnbd: correct all kernel-doc complaints
  blk-mq: use queue_hctx in blk_mq_map_queue_type
  md: remove legacy 1s delay in md_notify_reboot
  md/raid5: fix IO hang when array is broken with IO inflight
  md: warn about updating super block failure
  md/raid0: fix NULL pointer dereference in create_strip_zones() for dm-raid
  sbitmap: fix all kernel-doc warnings
  ublk: add helper of __ublk_fetch()
  ublk: pass const pointer to ublk_queue_is_zoned()
  ublk: refactor auto buffer register in ublk_dispatch_req()
  ublk: add `union ublk_io_buf` with improved naming
  ublk: add parameter `struct io_uring_cmd *` to ublk_prep_auto_buf_reg()
  kfifo: add kfifo_alloc_node() helper for NUMA awareness
  blk-mq: fix potential uaf for 'queue_hw_ctx'
  blk-mq: use array manage hctx map instead of xarray
  ublk: prevent invalid access with DEBUG
  s390/dasd: Use scnprintf() instead of sprintf()
  s390/dasd: Move device name formatting into separate function
  s390/dasd: Remove unnecessary debugfs_create() return checks
  s390/dasd: Fix gendisk parent after copy pair swap
  ...
2025-12-03 19:26:18 -08:00
Linus Torvalds
0abcfd8983 Merge tag 'for-6.19/io_uring-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull io_uring updates from Jens Axboe:

 - Unify how task_work cancelations are detected, placing it in the
   task_work running state rather than needing to check the task state

 - Series cleaning up and moving the cancelation code to where it
   belongs, in cancel.c

 - Cleanup of waitid and futex argument handling

 - Add support for mixed sized SQEs. 6.18 added support for mixed sized
   CQEs, improving flexibility and efficiency of workloads that need big
   CQEs. This adds similar support for SQEs, where the occasional need
   for a 128b SQE doesn't necessitate having all SQEs be 128b in size

 - Introduce zcrx and SQ/CQ layout queries. The former returns what zcrx
   features are available. And both return the ring size information to
   help with allocation size calculation for user provided rings like
   IORING_SETUP_NO_MMAP and IORING_MEM_REGION_TYPE_USER

 - Zcrx updates for 6.19. It includes a bunch of small patches,
   IORING_REGISTER_ZCRX_CTRL and RQ flushing and David's work on sharing
   zcrx b/w multiple io_uring instances

 - Series cleaning up ring initializations, notable deduplicating ring
   size and offset calculations. It also moves most of the checking
   before doing any allocations, making the code simpler

 - Add support for getsockname and getpeername, which is mostly a
   trivial hookup after a bit of refactoring on the networking side

 - Various fixes and cleanups

* tag 'for-6.19/io_uring-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (68 commits)
  io_uring: Introduce getsockname io_uring cmd
  socket: Split out a getsockname helper for io_uring
  socket: Unify getsockname and getpeername implementation
  io_uring/query: drop unused io_handle_query_entry() ctx arg
  io_uring/kbuf: remove obsolete buf_nr_pages and update comments
  io_uring/register: use correct location for io_rings_layout
  io_uring/zcrx: share an ifq between rings
  io_uring/zcrx: add io_fill_zcrx_offsets()
  io_uring/zcrx: export zcrx via a file
  io_uring/zcrx: move io_zcrx_scrub() and dependencies up
  io_uring/zcrx: count zcrx users
  io_uring/zcrx: add sync refill queue flushing
  io_uring/zcrx: introduce IORING_REGISTER_ZCRX_CTRL
  io_uring/zcrx: elide passing msg flags
  io_uring/zcrx: use folio_nr_pages() instead of shift operation
  io_uring/zcrx: convert to use netmem_desc
  io_uring/query: introduce rings info query
  io_uring/query: introduce zcrx query
  io_uring: move cq/sq user offset init around
  io_uring: pre-calculate scq layout
  ...
2025-12-03 18:58:57 -08:00
Linus Torvalds
9368f0f941 Merge tag 'vfs-6.19-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs inode updates from Christian Brauner:
 "Features:

   - Hide inode->i_state behind accessors. Open-coded accesses prevent
     asserting they are done correctly. One obvious aspect is locking,
     but significantly more can be checked. For example it can be
     detected when the code is clearing flags which are already missing,
     or is setting flags when it is illegal (e.g., I_FREEING when
     ->i_count > 0)

   - Provide accessors for ->i_state, converts all filesystems using
     coccinelle and manual conversions (btrfs, ceph, smb, f2fs, gfs2,
     overlayfs, nilfs2, xfs), and makes plain ->i_state access fail to
     compile

   - Rework I_NEW handling to operate without fences, simplifying the
     code after the accessor infrastructure is in place

  Cleanups:

   - Move wait_on_inode() from writeback.h to fs.h

   - Spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb
     for clarity

   - Cosmetic fixes to LRU handling

   - Push list presence check into inode_io_list_del()

   - Touch up predicts in __d_lookup_rcu()

   - ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage

   - Assert on ->i_count in iput_final()

   - Assert ->i_lock held in __iget()

  Fixes:

   - Add missing fences to I_NEW handling"

* tag 'vfs-6.19-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (22 commits)
  dcache: touch up predicts in __d_lookup_rcu()
  fs: push list presence check into inode_io_list_del()
  fs: cosmetic fixes to lru handling
  fs: rework I_NEW handling to operate without fences
  fs: make plain ->i_state access fail to compile
  xfs: use the new ->i_state accessors
  nilfs2: use the new ->i_state accessors
  overlayfs: use the new ->i_state accessors
  gfs2: use the new ->i_state accessors
  f2fs: use the new ->i_state accessors
  smb: use the new ->i_state accessors
  ceph: use the new ->i_state accessors
  btrfs: use the new ->i_state accessors
  Manual conversion to use ->i_state accessors of all places not covered by coccinelle
  Coccinelle-based conversion to use ->i_state accessors
  fs: provide accessors for ->i_state
  fs: spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb
  fs: move wait_on_inode() from writeback.h to fs.h
  fs: add missing fences to I_NEW handling
  ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage
  ...
2025-12-01 09:02:34 -08:00
Linus Torvalds
b04b2e7a61 Merge tag 'vfs-6.19-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
 "Features:

   - Cheaper MAY_EXEC handling for path lookup. This elides MAY_WRITE
     permission checks during path lookup and adds the
     IOP_FASTPERM_MAY_EXEC flag so filesystems like btrfs can avoid
     expensive permission work.

   - Hide dentry_cache behind runtime const machinery.

   - Add German Maglione as virtiofs co-maintainer.

  Cleanups:

   - Tidy up and inline step_into() and walk_component() for improved
     code generation.

   - Re-enable IOCB_NOWAIT writes to files. This refactors file
     timestamp update logic, fixing a layering bypass in btrfs when
     updating timestamps on device files and improving FMODE_NOCMTIME
     handling in VFS now that nfsd started using it.

   - Path lookup optimizations extracting slowpaths into dedicated
     routines and adding branch prediction hints for mntput_no_expire(),
     fd_install(), lookup_slow(), and various other hot paths.

   - Enable clang's -fms-extensions flag, requiring a JFS rename to
     avoid conflicts.

   - Remove spurious exports in fs/file_attr.c.

   - Stop duplicating union pipe_index declaration. This depends on the
     shared kbuild branch that brings in -fms-extensions support which
     is merged into this branch.

   - Use MD5 library instead of crypto_shash in ecryptfs.

   - Use largest_zero_folio() in iomap_dio_zero().

   - Replace simple_strtol/strtoul with kstrtoint/kstrtouint in init and
     initrd code.

   - Various typo fixes.

  Fixes:

   - Fix emergency sync for btrfs. Btrfs requires an explicit sync_fs()
     call with wait == 1 to commit super blocks. The emergency sync path
     never passed this, leaving btrfs data uncommitted during emergency
     sync.

   - Use local kmap in watch_queue's post_one_notification().

   - Add hint prints in sb_set_blocksize() for LBS dependency on THP"

* tag 'vfs-6.19-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
  MAINTAINERS: add German Maglione as virtiofs co-maintainer
  fs: inline step_into() and walk_component()
  fs: tidy up step_into() & friends before inlining
  orangefs: use inode_update_timestamps directly
  btrfs: fix the comment on btrfs_update_time
  btrfs: use vfs_utimes to update file timestamps
  fs: export vfs_utimes
  fs: lift the FMODE_NOCMTIME check into file_update_time_flags
  fs: refactor file timestamp update logic
  include/linux/fs.h: trivial fix: regualr -> regular
  fs/splice.c: trivial fix: pipes -> pipe's
  fs: mark lookup_slow() as noinline
  fs: add predicts based on nd->depth
  fs: move mntput_no_expire() slowpath into a dedicated routine
  fs: remove spurious exports in fs/file_attr.c
  watch_queue: Use local kmap in post_one_notification()
  fs: touch up predicts in path lookup
  fs: move fd_install() slowpath into a dedicated routine and provide commentary
  fs: hide dentry_cache behind runtime const machinery
  fs: touch predicts in do_dentry_open()
  ...
2025-12-01 08:44:26 -08:00
Linus Torvalds
1885cdbfbb Merge tag 'vfs-6.19-rc1.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull iomap updates from Christian Brauner:
 "FUSE iomap Support for Buffered Reads:

    This adds iomap support for FUSE buffered reads and readahead. This
    enables granular uptodate tracking with large folios so only
    non-uptodate portions need to be read. Also fixes a race condition
    with large folios + writeback cache that could cause data corruption
    on partial writes followed by reads.

     - Refactored iomap read/readahead bio logic into helpers
     - Added caller-provided callbacks for read operations
     - Moved buffered IO bio logic into new file
     - FUSE now uses iomap for read_folio and readahead

  Zero Range Folio Batch Support:

    Add folio batch support for iomap_zero_range() to handle dirty
    folios over unwritten mappings. Fix raciness issues where dirty data
    could be lost during zero range operations.

     - filemap_get_folios_tag_range() helper for dirty folio lookup
     - Optional zero range dirty folio processing
     - XFS fills dirty folios on zero range of unwritten mappings
     - Removed old partial EOF zeroing optimization

  DIO Write Completions from Interrupt Context:

    Restore pre-iomap behavior where pure overwrite completions run
    inline rather than being deferred to workqueue. Reduces context
    switches for high-performance workloads like ScyllaDB.

     - Removed unused IOCB_DIO_CALLER_COMP code
     - Error completions always run in user context (fixes zonefs)
     - Reworked REQ_FUA selection logic
     - Inverted IOMAP_DIO_INLINE_COMP to IOMAP_DIO_OFFLOAD_COMP

  Buffered IO Cleanups:

    Some performance and code clarity improvements:

     - Replace manual bitmap scanning with find_next_bit()
     - Simplify read skip logic for writes
     - Optimize pending async writeback accounting
     - Better variable naming
     - Documentation for iomap_finish_folio_write() requirements

  Misaligned Vectors for Zoned XFS:

    Enables sub-block aligned vectors in XFS always-COW mode for zoned
    devices via new IOMAP_DIO_FSBLOCK_ALIGNED flag.

  Bug Fixes:

     - Allocate s_dio_done_wq for async reads (fixes syzbot report after
       error completion changes)
     - Fix iomap_read_end() for already uptodate folios (regression fix)"

* tag 'vfs-6.19-rc1.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (40 commits)
  iomap: allocate s_dio_done_wq for async reads as well
  iomap: fix iomap_read_end() for already uptodate folios
  iomap: invert the polarity of IOMAP_DIO_INLINE_COMP
  iomap: support write completions from interrupt context
  iomap: rework REQ_FUA selection
  iomap: always run error completions in user context
  fs, iomap: remove IOCB_DIO_CALLER_COMP
  iomap: use find_next_bit() for uptodate bitmap scanning
  iomap: use find_next_bit() for dirty bitmap scanning
  iomap: simplify when reads can be skipped for writes
  iomap: simplify ->read_folio_range() error handling for reads
  iomap: optimize pending async writeback accounting
  docs: document iomap writeback's iomap_finish_folio_write() requirement
  iomap: account for unaligned end offsets when truncating read range
  iomap: rename bytes_pending/bytes_accounted to bytes_submitted/bytes_not_submitted
  xfs: support sub-block aligned vectors in always COW mode
  iomap: add IOMAP_DIO_FSBLOCK_ALIGNED flag
  xfs: error tag to force zeroing on debug kernels
  iomap: remove old partial eof zeroing optimization
  xfs: fill dirty folios on zero range of unwritten mappings
  ...
2025-12-01 08:14:00 -08:00
Fengnan Chang
4d0e1f2139 blk-mq: use queue_hctx in blk_mq_map_queue_type
Some caller of blk_mq_map_queue_type now didn't grab
'q_usage_counter', such as blk_mq_cpu_mapped_to_hctx, so we need
protect 'queue_hw_ctx' through rcu.

Also checked all other functions, no more missed cases.

Fixes: 89e1fb7cef ("blk-mq: fix potential uaf for 'queue_hw_ctx'")
Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-12-01 07:18:31 -07:00
Fengnan Chang
89e1fb7cef blk-mq: fix potential uaf for 'queue_hw_ctx'
This is just apply Kuai's patch in [1] with mirror changes.

blk_mq_realloc_hw_ctxs() will free the 'queue_hw_ctx'(e.g. undate
submit_queues through configfs for null_blk), while it might still be
used from other context(e.g. switch elevator to none):

t1					t2
elevator_switch
 blk_mq_unquiesce_queue
  blk_mq_run_hw_queues
   queue_for_each_hw_ctx
    // assembly code for hctx = (q)->queue_hw_ctx[i]
    mov    0x48(%rbp),%rdx -> read old queue_hw_ctx

					__blk_mq_update_nr_hw_queues
					 blk_mq_realloc_hw_ctxs
					  hctxs = q->queue_hw_ctx
					  q->queue_hw_ctx = new_hctxs
					  kfree(hctxs)
    movslq %ebx,%rax
    mov    (%rdx,%rax,8),%rdi ->uaf

This problem was found by code review, and I comfirmed that the concurrent
scenario do exist(specifically 'q->queue_hw_ctx' can be changed during
blk_mq_run_hw_queues()), however, the uaf problem hasn't been repoduced yet
without hacking the kernel.

Sicne the queue is freezed in __blk_mq_update_nr_hw_queues(), fix the
problem by protecting 'queue_hw_ctx' through rcu where it can be accessed
without grabbing 'q_usage_counter'.

[1] https://lore.kernel.org/all/20220225072053.2472431-1-yukuai3@huawei.com/

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-11-28 09:09:19 -07:00
Fengnan Chang
d0c98769ee blk-mq: use array manage hctx map instead of xarray
After commit 4e5cc99e1e ("blk-mq: manage hctx map via xarray"), we use
an xarray instead of array to store hctx, but in poll mode, each time
in blk_mq_poll, we need use xa_load to find corresponding hctx, this
introduce some costs. In my test, xa_load may cost 3.8% cpu.

This patch revert previous change, eliminates the overhead of xa_load
and can result in a 3% performance improvement.

Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-11-28 09:09:19 -07:00
Chaitanya Kulkarni
7d09a8e251 block: ignore __blkdev_issue_discard() return value
__blkdev_issue_discard() always returns 0, making the error check
in blkdev_issue_discard() dead code.

In function blkdev_issue_discard() initialize ret = 0, remove ret
assignment from __blkdev_issue_discard(), rely on bio == NULL check to
call submit_bio_wait(), preserve submit_bio_wait() error handling, and
preserve -EOPNOTSUPP to 0 mapping.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-11-25 12:19:39 -07:00
shechenglong
3a64c46c40 block: fix typos in comments and strings in blk-core
This patch fixes multiple spelling mistakes in comments and documentation
in the file block/blk-core.c.

No functional changes intended.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: shechenglong <shechenglong@xfusion.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-11-25 10:39:49 -07:00
John Garry
a74de0c366 block: Remove references to __device_add_disk()
Since commit d1254a8749 ("block: remove support for delayed queue
registrations"), function __device_add_disk() has been replaced with
device_add_disk(), so fix up comments.

Signed-off-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-11-25 10:36:37 -07:00
Leon Romanovsky
d4504262f7 PCI/P2PDMA: Simplify bus address mapping API
Update the pci_p2pdma_bus_addr_map() function to take a direct pointer
to the p2pdma_provider structure instead of the pci_p2pdma_map_state.
This simplifies the API by removing the need for callers to extract
the provider from the state structure.

The change updates all callers across the kernel (block layer, IOMMU,
DMA direct, and HMM) to pass the provider pointer directly, making
the code more explicit and reducing unnecessary indirection. This
also removes the runtime warning check since callers now have direct
control over which provider they use.

Tested-by: Alex Mastro <amastro@fb.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Ankit Agrawal <ankita@nvidia.com>
Link: https://lore.kernel.org/r/20251120-dmabuf-vfio-v9-2-d7f71607f371@nvidia.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
2025-11-20 12:01:41 -07:00