Linux kernel ============ The Linux kernel is the core of any Linux operating system. It manages hardware, system resources, and provides the fundamental services for all other software. Quick Start ----------- * Report a bug: See Documentation/admin-guide/reporting-issues.rst * Get the latest kernel: https://kernel.org * Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst * Join the community: https://lore.kernel.org/ Essential Documentation ----------------------- All users should be familiar with: * Building requirements: Documentation/process/changes.rst * Code of Conduct: Documentation/process/code-of-conduct.rst * License: See COPYING Documentation can be built with make htmldocs or viewed online at: https://www.kernel.org/doc/html/latest/ Who Are You? ============ Find your role below: * New Kernel Developer - Getting started with kernel development * Academic Researcher - Studying kernel internals and architecture * Security Expert - Hardening and vulnerability analysis * Backport/Maintenance Engineer - Maintaining stable kernels * System Administrator - Configuring and troubleshooting * Maintainer - Leading subsystems and reviewing patches * Hardware Vendor - Writing drivers for new hardware * Distribution Maintainer - Packaging kernels for distros * AI Coding Assistant - LLMs and AI-powered development tools For Specific Users ================== New Kernel Developer -------------------- Welcome! Start your kernel development journey here: * Getting Started: Documentation/process/development-process.rst * Your First Patch: Documentation/process/submitting-patches.rst * Coding Style: Documentation/process/coding-style.rst * Build System: Documentation/kbuild/index.rst * Development Tools: Documentation/dev-tools/index.rst * Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst * Core APIs: Documentation/core-api/index.rst Academic Researcher ------------------- Explore the kernel's architecture and internals: * Researcher Guidelines: Documentation/process/researcher-guidelines.rst * Memory Management: Documentation/mm/index.rst * Scheduler: Documentation/scheduler/index.rst * Networking Stack: Documentation/networking/index.rst * Filesystems: Documentation/filesystems/index.rst * RCU (Read-Copy Update): Documentation/RCU/index.rst * Locking Primitives: Documentation/locking/index.rst * Power Management: Documentation/power/index.rst Security Expert --------------- Security documentation and hardening guides: * Security Documentation: Documentation/security/index.rst * LSM Development: Documentation/security/lsm-development.rst * Self Protection: Documentation/security/self-protection.rst * Reporting Vulnerabilities: Documentation/process/security-bugs.rst * CVE Procedures: Documentation/process/cve.rst * Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst * Security Features: Documentation/userspace-api/seccomp_filter.rst Backport/Maintenance Engineer ----------------------------- Maintain and stabilize kernel versions: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * Backporting Guide: Documentation/process/backporting.rst * Applying Patches: Documentation/process/applying-patches.rst * Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git for Maintainers: Documentation/maintainer/configure-git.rst System Administrator -------------------- Configure, tune, and troubleshoot Linux systems: * Admin Guide: Documentation/admin-guide/index.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst * Tracing/Debugging: Documentation/trace/index.rst * Performance Security: Documentation/admin-guide/perf-security.rst * Hardware Monitoring: Documentation/hwmon/index.rst Maintainer ---------- Lead kernel subsystems and manage contributions: * Maintainer Handbook: Documentation/maintainer/index.rst * Pull Requests: Documentation/maintainer/pull-requests.rst * Managing Patches: Documentation/maintainer/modifying-patches.rst * Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst * Development Process: Documentation/process/maintainer-handbooks.rst * Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git Configuration: Documentation/maintainer/configure-git.rst Hardware Vendor --------------- Write drivers and support new hardware: * Driver API Guide: Documentation/driver-api/index.rst * Driver Model: Documentation/driver-api/driver-model/driver.rst * Device Drivers: Documentation/driver-api/infrastructure.rst * Bus Types: Documentation/driver-api/driver-model/bus.rst * Device Tree Bindings: Documentation/devicetree/bindings/ * Power Management: Documentation/driver-api/pm/index.rst * DMA API: Documentation/core-api/dma-api.rst Distribution Maintainer ----------------------- Package and distribute the kernel: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * ABI Documentation: Documentation/ABI/README * Kernel Configuration: Documentation/kbuild/kconfig.rst * Module Signing: Documentation/admin-guide/module-signing.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst AI Coding Assistant ------------------- CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and follow the AI coding assistants documentation before contributing to the Linux kernel: * Documentation/process/coding-assistants.rst This documentation contains essential requirements about licensing, attribution, and the Developer Certificate of Origin that all AI tools must comply with. Communication and Support ========================= * Mailing Lists: https://lore.kernel.org/ * IRC: #kernelnewbies on irc.oftc.net * Bugzilla: https://bugzilla.kernel.org/ * MAINTAINERS file: Lists subsystem maintainers and mailing lists * Email Clients: Documentation/process/email-clients.rst
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1444589
3
929
Clone this repository
https://tangled.org/tjh.dev/kernel
https://tangled.org/did:plc:65gha4t3avpfpzmvpbwovss7/kernel
git@gordian.tjh.dev:tjh.dev/kernel
git@gordian.tjh.dev:did:plc:65gha4t3avpfpzmvpbwovss7/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
Introduce the new max_open_zones option to allow specifying a limit on
the maximum number of open zones of a zloop device. This change allows
creating a zloop device that can more closely mimick the characteristics
of a physical SMR drive.
When set to a non zero value, only up to max_open_zones zones can be in
the implicit open (BLK_ZONE_COND_IMP_OPEN) and explicit open
(BLK_ZONE_COND_EXP_OPEN) conditions at any time. The transition to the
implicit open condition of a zone on a write operation can result in an
implicit close of an already implicitly open zone. This is handled in
the function zloop_do_open_zone(). This function also handles
transitions to the explicit open condition. Implicit close transitions
are handled using an LRU ordered list of open zones which is managed
using the helper functions zloop_lru_rotate_open_zone() and
zloop_lru_remove_open_zone().
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260326203245.946830-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When blk_revalidate_disk_zones() fails after disk_revalidate_zone_resources()
has allocated args.zones_cond, the memory is leaked because no error path
frees it.
Fixes: 6e945ffb6555 ("block: use zone condition to determine conventional zones")
Suggested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Link: https://patch.msgid.link/20260331111216.24242-1-liu.yun@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When LOOP_CONFIGURE is called with LO_FLAGS_PARTSCAN, the following
sequence occurs:
1. disk_force_media_change() sets GD_NEED_PART_SCAN
2. Uevent suppression is lifted and a KOBJ_CHANGE uevent is sent
3. loop_global_unlock() releases the lock
4. loop_reread_partitions() calls bdev_disk_changed() to scan
There is a race between steps 2 and 4: when udev receives the uevent
and opens the device before loop_reread_partitions() runs,
blkdev_get_whole() in bdev.c sees GD_NEED_PART_SCAN set and calls
bdev_disk_changed() for a first scan. Then loop_reread_partitions()
does a second scan. The open_mutex serializes these two scans, but
does not prevent both from running.
The second scan in bdev_disk_changed() drops all partition devices
from the first scan (via blk_drop_partitions()) before re-adding
them, causing partition block devices to briefly disappear. This
breaks any systemd unit with BindsTo= on the partition device: systemd
observes the device going dead, fails the dependent units, and does
not retry them when the device reappears.
Fix this by removing the GD_NEED_PART_SCAN set from
disk_force_media_change() entirely. None of the current callers need
the lazy on-open partition scan triggered by this flag:
- floppy: sets GENHD_FL_NO_PART, so disk_has_partscan() is always
false and GD_NEED_PART_SCAN has no effect.
- loop (loop_configure, loop_change_fd): when LO_FLAGS_PARTSCAN is
set, loop_reread_partitions() performs an explicit scan. When not
set, GD_SUPPRESS_PART_SCAN prevents the lazy scan path.
- loop (__loop_clr_fd): calls bdev_disk_changed() explicitly if
LO_FLAGS_PARTSCAN is set.
- nbd (nbd_clear_sock_ioctl): capacity is set to zero immediately
after; nbd manages GD_NEED_PART_SCAN explicitly elsewhere.
With GD_NEED_PART_SCAN no longer set by disk_force_media_change(),
udev opening the loop device after the uevent no longer triggers a
redundant scan in blkdev_get_whole(), and only the single explicit
scan from loop_reread_partitions() runs.
A regression test for this bug has been submitted to blktests:
https://github.com/linux-blktests/blktests/pull/240.
Fixes: 9f65c489b68d ("loop: raise media_change event")
Signed-off-by: Daan De Meyer <daan@amutable.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://patch.msgid.link/20260331105130.1077599-1-daan@amutable.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The TCG Opal device could enter a state where no new session can be
created, blocking even Discovery or PSID reset. While a power cycle
or waiting for the timeout should work, there is another possibility
for recovery: using the Stack Reset command.
The Stack Reset command is defined in the TCG Storage Architecture Core
Specification and is mandatory for all Opal devices (see Section 3.3.6
of the Opal SSC specification).
This patch implements the Stack Reset command. Sending it should clear
all active sessions immediately, allowing subsequent commands to run
successfully. While it is a TCG transport layer command, the Linux
kernel implements only Opal ioctls, so it makes sense to use the
IOC_OPAL ioctl interface.
The Stack Reset takes no arguments; the response can be success or pending.
If the command reports a pending state, userspace can try to repeat it;
in this case, the code returns -EBUSY.
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Reviewed-by: Ondrej Kozina <okozina@redhat.com>
Link: https://patch.msgid.link/20260310095349.411287-1-gmazyland@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull NVMe updates from Keith:
"- Fabrics authentication updates (Eric, Alistar)
- Enanced block queue limits support (Caleb)
- Workqueue usage updates (Marco)
- A new write zeroes device quirk (Robert)
- Tagset cleanup fix for loop device (Nilay)"
* tag 'nvme-7.1-2026-03-27' of git://git.infradead.org/nvme: (41 commits)
nvme-loop: do not cancel I/O and admin tagset during ctrl reset/shutdown
nvme: add WQ_PERCPU to alloc_workqueue users
nvmet-fc: add WQ_PERCPU to alloc_workqueue users
nvmet: replace use of system_wq with system_percpu_wq
nvme-auth: Don't propose NVME_AUTH_DHGROUP_NULL with SC_C
nvme: Add the DHCHAP maximum HD IDs
nvme-pci: add NVME_QUIRK_DISABLE_WRITE_ZEROES for Kingston OM3SGP4
nvme: respect NVME_QUIRK_DISABLE_WRITE_ZEROES when wzsl is set
nvmet: report NPDGL and NPDAL
nvmet: use NVME_NS_FEAT_OPTPERF_SHIFT
nvme: set discard_granularity from NPDG/NPDA
nvme: add from0based() helper
nvme: always issue I/O Command Set specific Identify Namespace
nvme: update nvme_id_ns OPTPERF constants
nvme: fold nvme_config_discard() into nvme_update_disk_info()
nvme: add preferred I/O size fields to struct nvme_id_ns_nvm
nvme: Allow reauth from sysfs
nvme: Expose the tls_configured sysfs for secure concat connections
nvmet-tcp: Don't free SQ on authentication success
nvmet-tcp: Don't error if TLS is enabed on a reset
...
Make drbd_adm_dump_devices() call rcu_read_lock() before
rcu_read_unlock() is called. This has been detected by the Clang
thread-safety analyzer.
Tested-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Fixes: a55bbd375d18 ("drbd: Backport the "status" command")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260326214054.284593-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cancelling the I/O and admin tagsets during nvme-loop controller reset
or shutdown is unnecessary. The subsequent destruction of the I/O and
admin queues already waits for all in-flight target operations to
complete.
Cancelling the tagsets first also opens a race window. After a request
tag has been cancelled, a late completion from the target may still
arrive before the queues are destroyed. In that case the completion path
may access a request whose tag has already been cancelled or freed,
which can lead to a kernel crash. Please see below the kernel crash
encountered while running blktests nvme/040:
run blktests nvme/040 at 2026-03-08 06:34:27
loop0: detected capacity change from 0 to 2097152
nvmet: adding nsid 1 to subsystem blktests-subsystem-1
nvmet: Created nvm controller 1 for subsystem blktests-subsystem-1 for NQN nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349.
nvme nvme6: creating 96 I/O queues.
nvme nvme6: new ctrl: "blktests-subsystem-1"
nvme_log_error: 1 callbacks suppressed
block nvme6n1: no usable path - requeuing I/O
nvme6c6n1: Read(0x2) @ LBA 2096384, 128 blocks, Host Aborted Command (sct 0x3 / sc 0x71)
blk_print_req_error: 1 callbacks suppressed
I/O error, dev nvme6c6n1, sector 2096384 op 0x0:(READ) flags 0x2880700 phys_seg 1 prio class 2
block nvme6n1: no usable path - requeuing I/O
Kernel attempted to read user page (236) - exploit attempt? (uid: 0)
BUG: Kernel NULL pointer dereference on read at 0x00000236
Faulting instruction address: 0xc000000000961274
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: nvme_loop nvme_fabrics loop nvmet null_blk rpadlpar_io rpaphp xsk_diag bonding rfkill nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink pseries_rng dax_pmem vmx_crypto drm drm_panel_orientation_quirks xfs mlx5_core nvme bnx2x sd_mod nd_pmem nd_btt nvme_core sg papr_scm tls libnvdimm ibmvscsi ibmveth scsi_transport_srp nvme_keyring nvme_auth mdio hkdf pseries_wdt dm_mirror dm_region_hash dm_log dm_mod fuse [last unloaded: loop]
CPU: 25 UID: 0 PID: 0 Comm: swapper/25 Kdump: loaded Not tainted 7.0.0-rc3+ #14 PREEMPT
Hardware name: IBM,9043-MRX Power11 (architected) 0x820200 0xf000007 of:IBM,FW1120.00 (RF1120_128) hv:phyp pSeries
NIP: c000000000961274 LR: c008000009af1808 CTR: c00000000096124c
REGS: c0000007ffc0f910 TRAP: 0300 Not tainted (7.0.0-rc3+)
MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 22222222 XER: 00000000
CFAR: c008000009af232c DAR: 0000000000000236 DSISR: 40000000 IRQMASK: 0
GPR00: c008000009af17fc c0000007ffc0fbb0 c000000001c78100 c0000000be05cc00
GPR04: 0000000000000001 0000000000000000 0000000000000007 0000000000000000
GPR08: 0000000000000000 0000000000000000 0000000000000002 c008000009af2318
GPR12: c00000000096124c c0000007ffdab880 0000000000000000 0000000000000000
GPR16: 0000000000000010 0000000000000000 0000000000000004 0000000000000000
GPR20: 0000000000000001 c000000002ca2b00 0000000100043bb2 000000000000000a
GPR24: 000000000000000a 0000000000000000 0000000000000000 0000000000000000
GPR28: c000000084021d40 c000000084021d50 c0000000be05cd60 c0000000be05cc00
NIP [c000000000961274] blk_mq_complete_request_remote+0x28/0x2d4
LR [c008000009af1808] nvme_loop_queue_response+0x110/0x290 [nvme_loop]
Call Trace:
0xc00000000502c640 (unreliable)
nvme_loop_queue_response+0x104/0x290 [nvme_loop]
__nvmet_req_complete+0x80/0x498 [nvmet]
nvmet_req_complete+0x24/0xf8 [nvmet]
nvmet_bio_done+0x58/0xcc [nvmet]
bio_endio+0x250/0x390
blk_update_request+0x2e8/0x68c
blk_mq_end_request+0x30/0x5c
lo_complete_rq+0x94/0x110 [loop]
blk_complete_reqs+0x78/0x98
handle_softirqs+0x148/0x454
do_softirq_own_stack+0x3c/0x50
__irq_exit_rcu+0x18c/0x1b4
irq_exit+0x1c/0x34
do_IRQ+0x114/0x278
hardware_interrupt_common_virt+0x28c/0x290
Since the queue teardown path already guarantees that all target-side
operations have completed, cancelling the tagsets is redundant and
unsafe. So avoid cancelling the I/O and admin tagsets during controller
reset and shutdown.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Every doit handler followed the same pattern: stack-allocate an
adm_ctx, call drbd_adm_prepare() at the top, call drbd_adm_finish()
at the bottom. This duplicated boilerplate across 25 handlers and
made error paths inconsistent, since some handlers could miss sending
the reply skb on early-exit paths.
The generic netlink framework already provides pre_doit/post_doit
hooks for exactly this purpose. An old comment even noted "this
would be a good candidate for a pre_doit hook".
Use them:
- pre_doit heap-allocates adm_ctx, looks up per-command flags from a
new drbd_genl_cmd_flags[] table, runs drbd_adm_prepare(), and
stores the context in info->user_ptr[0].
- post_doit sends the reply, drops kref references for
device/connection/resource, and frees the adm_ctx.
- Handlers just receive adm_ctx from info->user_ptr[0], set
reply_dh->ret_code, and return. All teardown is in post_doit.
- drbd_adm_finish() is removed, superseded by post_doit.
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://patch.msgid.link/20260324152907.2840984-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This continues the effort to refactor workqueue APIs, which began with
the introduction of new workqueues and a new alloc_workqueue flag in:
commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")
The refactoring is going to alter the default behavior of
alloc_workqueue() to be unbound by default.
With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU. For more details see the Link tag below.
In order to keep alloc_workqueue() behavior identical, explicitly request
WQ_PERCPU.
Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/
Suggested-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Add a new options that causes zloop to truncate the zone files to the
write pointer value recorded at the last cache flush to simulate
unclean shutdowns.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://patch.msgid.link/20260323071156.2940772-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This continues the effort to refactor workqueue APIs, which began with
the introduction of new workqueues and a new alloc_workqueue flag in:
commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")
The refactoring is going to alter the default behavior of
alloc_workqueue() to be unbound by default.
With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU. For more details see the Link tag below.
In order to keep alloc_workqueue() behavior identical, explicitly request
WQ_PERCPU.
Cc: Justin Tee <justin.tee@broadcom.com>
Cc: Naresh Gottumukkala <nareshgottumukkala83@gmail.com>
CC: Paul Ely <paul.ely@broadcom.com>
Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/
Suggested-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Split out two helpers functions to make the function more readable and
to avoid conditional locking.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://patch.msgid.link/20260323071156.2940772-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch continues the effort to refactor workqueue APIs, which has begun
with the changes introducing new workqueues and a new alloc_workqueue flag:
commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")
The point of the refactoring is to eventually alter the default behavior of
workqueues to become unbound by default so that their workload placement is
optimized by the scheduler.
Before that to happen, workqueue users must be converted to the better named
new workqueues with no intended behaviour changes:
system_wq -> system_percpu_wq
system_unbound_wq -> system_dfl_wq
This way the old obsolete workqueues (system_wq, system_unbound_wq) can be
removed in the future.
Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/
Suggested-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
bio_alloc_bioset() first strips __GFP_DIRECT_RECLAIM from the optimistic
fast allocation attempt with try_alloc_gfp(). If that fast path fails,
the slowpath checks saved_gfp to decide whether blocking allocation is
allowed, but then still calls mempool_alloc() with the stripped gfp mask.
That can lead to a NULL bio pointer being passed into bio_init().
Fix the slowpath by using saved_gfp for the bio and bvec mempool
allocations.
Fixes: b520c4eef83d ("block: split bio_alloc_bioset more clearly into a fast and slowpath")
Reported-by: syzbot+09ddb593eea76a158f42@syzkaller.appspotmail.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/p01.gc6e9ad5845ad.ttca29g@ub.hpns
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Section 8.3.4.5.2 of the NVMe 2.1 base spec states that
"""
The 00h identifier shall not be proposed in an AUTH_Negotiate message
that requests secure channel concatenation (i.e., with the SC_C field
set to a non-zero value).
"""
We need to ensure that we don't set the NVME_AUTH_DHGROUP_NULL idlist if
SC_C is set.
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chris Leech <cleech@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kamaljit Singh <kamaljit.singh@opensource.wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Mark ublk_filter_unused_tags() as noinline since it is only called from
the unlikely(needs_filter) branch. Extract the error-handling block from
__ublk_batch_dispatch() into a new noinline ublk_batch_dispatch_fail()
function to keep the hot path compact and icache-friendly. This also
makes __ublk_batch_dispatch() more readable by separating the error
recovery logic from the normal dispatch flow.
Before: __ublk_batch_dispatch is ~1419 bytes
After: __ublk_batch_dispatch is ~1090 bytes (-329 bytes, -23%)
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://patch.msgid.link/20260318014112.3125432-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
README