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2025-05-06x86/bpf: Call branch history clearing sequence on exitDaniel Sneddon
Classic BPF programs have been identified as potential vectors for intra-mode Branch Target Injection (BTI) attacks. Classic BPF programs can be run by unprivileged users. They allow unprivileged code to execute inside the kernel. Attackers can use unprivileged cBPF to craft branch history in kernel mode that can influence the target of indirect branches. Introduce a branch history buffer (BHB) clearing sequence during the JIT compilation of classic BPF programs. The clearing sequence is the same as is used in previous mitigations to protect syscalls. Since eBPF programs already have their own mitigations in place, only insert the call on classic programs that aren't run by privileged users. Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
2025-05-06Merge tag 'for-6.15/dm-fixes-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper fixes from Mikulas Patocka: - fix reading past the end of allocated memory - fix missing dm_put_live_table() in dm_keyslot_evict() * tag 'for-6.15/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm: fix copying after src array boundaries dm: add missing unlock on in dm_keyslot_evict()
2025-05-06smb3 client: warn when parse contexts returns error on compounded operationSteve French
Coverity noticed that the rc on smb2_parse_contexts() was not being checked in the case of compounded operations. Since we don't want to stop parsing the following compounded responses which are likely valid, we can't easily error out here, but at least print a warning message if server has a bug causing us to skip parsing the open response contexts. Addresses-Coverity: 1639191 Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-05-06can: gw: fix RCU/BH usage in cgw_create_job()Oliver Hartkopp
As reported by Sebastian Andrzej Siewior the use of local_bh_disable() is only feasible in uni processor systems to update the modification rules. The usual use-case to update the modification rules is to update the data of the modifications but not the modification types (AND/OR/XOR/SET) or the checksum functions itself. To omit additional memory allocations to maintain fast modification switching times, the modification description space is doubled at gw-job creation time so that only the reference to the active modification description is changed under rcu protection. Rename cgw_job::mod to cf_mod and make it a RCU pointer. Allocate in cgw_create_job() and free it together with cgw_job in cgw_job_free_rcu(). Update all users to dereference cgw_job::cf_mod with a RCU accessor and if possible once. [bigeasy: Replace mod1/mod2 from the Oliver's original patch with dynamic allocation, use RCU annotation and accessor] Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Closes: https://lore.kernel.org/linux-can/20231031112349.y0aLoBrz@linutronix.de/ Fixes: dd895d7f21b2 ("can: cangw: introduce optional uid to reference created routing jobs") Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20250429070555.cs-7b_eZ@linutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2025-05-06Merge patch series "can: rx-offload: fix order of unregistration calls"Marc Kleine-Budde
Marc Kleine-Budde <mkl@pengutronix.de> says: If a driver is removed, the driver framework invokes the driver's remove callback. A CAN driver's remove function calls unregister_candev(), which calls net_device_ops::ndo_stop further down in the call stack for interfaces which are in the "up" state. With the mcp251xfd driver the removal of the module causes the following warning: | WARNING: CPU: 0 PID: 352 at net/core/dev.c:7342 __netif_napi_del_locked+0xc8/0xd8 as can_rx_offload_del() deletes the NAPI, while it is still active, because the interface is still up. To fix the warning, first unregister the network interface, which calls net_device_ops::ndo_stop, which disables the NAPI, and then call can_rx_offload_del(). All other driver using the rx-offload helper have been checked and the same issue has been found in the rockchip and m_can driver. These have been fixed, but only compile time tested. On the mcp251xfd the fix was tested on hardware. Link: https://patch.msgid.link/20250502-can-rx-offload-del-v1-0-59a9b131589d@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2025-05-06can: mcan: m_can_class_unregister(): fix order of unregistration callsMarc Kleine-Budde
If a driver is removed, the driver framework invokes the driver's remove callback. A CAN driver's remove function calls unregister_candev(), which calls net_device_ops::ndo_stop further down in the call stack for interfaces which are in the "up" state. The removal of the module causes a warning, as can_rx_offload_del() deletes the NAPI, while it is still active, because the interface is still up. To fix the warning, first unregister the network interface, which calls net_device_ops::ndo_stop, which disables the NAPI, and then call can_rx_offload_del(). Fixes: 1be37d3b0414 ("can: m_can: fix periph RX path: use rx-offload to ensure skbs are sent from softirq context") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250502-can-rx-offload-del-v1-3-59a9b131589d@pengutronix.de Reviewed-by: Markus Schneider-Pargmann <msp@baylibre.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2025-05-06can: rockchip_canfd: rkcanfd_remove(): fix order of unregistration callsMarc Kleine-Budde
If a driver is removed, the driver framework invokes the driver's remove callback. A CAN driver's remove function calls unregister_candev(), which calls net_device_ops::ndo_stop further down in the call stack for interfaces which are in the "up" state. The removal of the module causes a warning, as can_rx_offload_del() deletes the NAPI, while it is still active, because the interface is still up. To fix the warning, first unregister the network interface, which calls net_device_ops::ndo_stop, which disables the NAPI, and then call can_rx_offload_del(). Fixes: ff60bfbaf67f ("can: rockchip_canfd: add driver for Rockchip CAN-FD controller") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250502-can-rx-offload-del-v1-2-59a9b131589d@pengutronix.de Reviewed-by: Markus Schneider-Pargmann <msp@baylibre.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2025-05-06nvme: use fdp streams if write stream is providedKeith Busch
Maps a user requested write stream to an FDP placement ID if possible. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250506121732.8211-12-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06nvme: register fdp parameters with the block layerKeith Busch
Register the device data placement limits if supported. This is just registering the limits with the block layer. Nothing beyond reporting these attributes is happening in this patch. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250506121732.8211-11-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06nvme: add FDP definitionsChristoph Hellwig
Add the config feature result, config log page, and management receive commands needed for FDP. Partially based on a patch from Kanchan Joshi <joshi.k@samsung.com>. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250506121732.8211-10-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06nvme: pass a void pointer to nvme_get/set_features for the resultChristoph Hellwig
That allows passing in structures instead of the u32 result, and thus reduce the amount of bit shifting and masking required to parse the result. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250506121732.8211-9-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06nvme: add a nvme_get_log_lsi helperChristoph Hellwig
For log pages that need to pass in a LSI value, while at the same time not touching all the existing nvme_get_log callers. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250506121732.8211-8-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06io_uring: enable per-io write streamsKeith Busch
Allow userspace to pass a per-I/O write stream in the SQE: __u8 write_stream; The __u8 type matches the size the filesystems and block layer support. Application can query the supported values from the block devices max_write_streams sysfs attribute. Unsupported values are ignored by file operations that do not support write streams or rejected with an error by those that support them. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250506121732.8211-7-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: expose write streams for block device nodesChristoph Hellwig
Use the per-kiocb write stream if provided, or map temperature hints to write streams (which is a bit questionable, but this shows how it is done). Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Signed-off-by: Christoph Hellwig <hch@lst.de> [kbusch: removed statx reporting] Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250506121732.8211-6-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: introduce a write_stream_granularity queue limitChristoph Hellwig
Export the granularity that write streams should be discarded with, as it is essential for making good use of them. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250506121732.8211-5-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: introduce max_write_streams queue limitKeith Busch
Drivers with hardware that support write streams need a way to export how many are available so applications can generically query this. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Signed-off-by: Keith Busch <kbusch@kernel.org> [hch: renamed hints to streams, removed stacking] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250506121732.8211-4-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: add a bi_write_stream fieldChristoph Hellwig
Add the ability to pass a write stream for placement control in the bio. The new field fits in an existing hole, so does not change the size of the struct. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250506121732.8211-3-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06fs: add a write stream field to the kiocbChristoph Hellwig
Prepare for io_uring passthrough of write streams. The write stream field in the kiocb structure fits into an existing 2-byte hole, so its size is not changed. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250506121732.8211-2-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: only update request sector if neededJohannes Thumshirn
In case of a ZONE APPEND write, regardless of native ZONE APPEND or the emulation layer in the zone write plugging code, the sector the data got written to by the device needs to be updated in the bio. At the moment, this is done for every native ZONE APPEND write and every request that is flagged with 'BIO_ZONE_WRITE_PLUGGING'. But thus superfluously updates the sector for regular writes to a zoned block device. Check if a bio is a native ZONE APPEND write or if the bio is flagged as 'BIO_EMULATES_ZONE_APPEND', meaning the block layer's zone write plugging code handles the ZONE APPEND and translates it into a regular write and back. Only if one of these two criterion is met, update the sector in the bio upon completion. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/dea089581cb6b777c1cd1500b38ac0b61df4b2d1.1746530748.git.jth@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06can: mcp251xfd: mcp251xfd_remove(): fix order of unregistration callsMarc Kleine-Budde
If a driver is removed, the driver framework invokes the driver's remove callback. A CAN driver's remove function calls unregister_candev(), which calls net_device_ops::ndo_stop further down in the call stack for interfaces which are in the "up" state. With the mcp251xfd driver the removal of the module causes the following warning: | WARNING: CPU: 0 PID: 352 at net/core/dev.c:7342 __netif_napi_del_locked+0xc8/0xd8 as can_rx_offload_del() deletes the NAPI, while it is still active, because the interface is still up. To fix the warning, first unregister the network interface, which calls net_device_ops::ndo_stop, which disables the NAPI, and then call can_rx_offload_del(). Fixes: 55e5b97f003e ("can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250502-can-rx-offload-del-v1-1-59a9b131589d@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2025-05-06can: mcp251xfd: fix TDC setting for low data bit ratesKelsey Maes
The TDC is currently hardcoded enabled. This means that even for lower CAN-FD data bitrates (with a DBRP (data bitrate prescaler) > 2) a TDC is configured. This leads to a bus-off condition. ISO 11898-1 section 11.3.3 says "Transmitter delay compensation" (TDC) is only applicable if DBRP is 1 or 2. To fix the problem, switch the driver to use the TDC calculation provided by the CAN driver framework (which respects ISO 11898-1 section 11.3.3). This has the positive side effect that userspace can control TDC as needed. Demonstration of the feature in action: | $ ip link set can0 up type can bitrate 125000 dbitrate 500000 fd on | $ ip -details link show can0 | 3: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 72 qdisc pfifo_fast state UP mode DEFAULT group default qlen 10 | link/can promiscuity 0 allmulti 0 minmtu 0 maxmtu 0 | can <FD> state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0 | bitrate 125000 sample-point 0.875 | tq 50 prop-seg 69 phase-seg1 70 phase-seg2 20 sjw 10 brp 2 | mcp251xfd: tseg1 2..256 tseg2 1..128 sjw 1..128 brp 1..256 brp_inc 1 | dbitrate 500000 dsample-point 0.875 | dtq 125 dprop-seg 6 dphase-seg1 7 dphase-seg2 2 dsjw 1 dbrp 5 | mcp251xfd: dtseg1 1..32 dtseg2 1..16 dsjw 1..16 dbrp 1..256 dbrp_inc 1 | tdcv 0..63 tdco 0..63 | clock 40000000 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 tso_max_size 65536 tso_max_segs 65535 gro_max_size 65536 parentbus spi parentdev spi0.0 | $ ip link set can0 up type can bitrate 1000000 dbitrate 4000000 fd on | $ ip -details link show can0 | 3: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 72 qdisc pfifo_fast state UP mode DEFAULT group default qlen 10 | link/can promiscuity 0 allmulti 0 minmtu 0 maxmtu 0 | can <FD,TDC-AUTO> state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0 | bitrate 1000000 sample-point 0.750 | tq 25 prop-seg 14 phase-seg1 15 phase-seg2 10 sjw 5 brp 1 | mcp251xfd: tseg1 2..256 tseg2 1..128 sjw 1..128 brp 1..256 brp_inc 1 | dbitrate 4000000 dsample-point 0.700 | dtq 25 dprop-seg 3 dphase-seg1 3 dphase-seg2 3 dsjw 1 dbrp 1 | tdco 7 | mcp251xfd: dtseg1 1..32 dtseg2 1..16 dsjw 1..16 dbrp 1..256 dbrp_inc 1 | tdcv 0..63 tdco 0..63 | clock 40000000 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 tso_max_size 65536 tso_max_segs 65535 gro_max_size 65536 parentbus spi parentdev spi0.0 There has been some confusion about the MCP2518FD using a relative or absolute TDCO due to the datasheet specifying a range of [-64,63]. I have a custom board with a 40 MHz clock and an estimated loop delay of 100 to 216 ns. During testing at a data bit rate of 4 Mbit/s I found that using can_get_relative_tdco() resulted in bus-off errors. The final TDCO value was 1 which corresponds to a 10% SSP in an absolute configuration. This behavior is expected if the TDCO value is really absolute and not relative. Using priv->can.tdc.tdco instead results in a final TDCO of 8, setting the SSP at exactly 80%. This configuration works. The automatic, manual, and off TDC modes were tested at speeds up to, and including, 8 Mbit/s on real hardware and behave as expected. Fixes: 55e5b97f003e ("can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN") Reported-by: Kelsey Maes <kelsey@vpprocess.com> Closes: https://lore.kernel.org/all/C2121586-C87F-4B23-A933-845362C29CA1@vpprocess.com Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Kelsey Maes <kelsey@vpprocess.com> Link: https://patch.msgid.link/20250430161501.79370-1-kelsey@vpprocess.com [mkl: add comment] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2025-05-06block: only update request sector if neededJohannes Thumshirn
In case of a ZONE APPEND write, regardless of native ZONE APPEND or the emulation layer in the zone write plugging code, the sector the data got written to by the device needs to be updated in the bio. At the moment, this is done for every native ZONE APPEND write and every request that is flagged with 'BIO_ZONE_WRITE_PLUGGING'. But thus superfluously updates the sector for regular writes to a zoned block device. Check if a bio is a native ZONE APPEND write or if the bio is flagged as 'BIO_EMULATES_ZONE_APPEND', meaning the block layer's zone write plugging code handles the ZONE APPEND and translates it into a regular write and back. Only if one of these two criterion is met, update the sector in the bio upon completion. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/dea089581cb6b777c1cd1500b38ac0b61df4b2d1.1746530748.git.jth@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06can: m_can: m_can_class_allocate_dev(): initialize spin lock on device probeAntonios Salios
The spin lock tx_handling_spinlock in struct m_can_classdev is not being initialized. This leads the following spinlock bad magic complaint from the kernel, eg. when trying to send CAN frames with cansend from can-utils: | BUG: spinlock bad magic on CPU#0, cansend/95 | lock: 0xff60000002ec1010, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 | CPU: 0 UID: 0 PID: 95 Comm: cansend Not tainted 6.15.0-rc3-00032-ga79be02bba5c #5 NONE | Hardware name: MachineWare SIM-V (DT) | Call Trace: | [<ffffffff800133e0>] dump_backtrace+0x1c/0x24 | [<ffffffff800022f2>] show_stack+0x28/0x34 | [<ffffffff8000de3e>] dump_stack_lvl+0x4a/0x68 | [<ffffffff8000de70>] dump_stack+0x14/0x1c | [<ffffffff80003134>] spin_dump+0x62/0x6e | [<ffffffff800883ba>] do_raw_spin_lock+0xd0/0x142 | [<ffffffff807a6fcc>] _raw_spin_lock_irqsave+0x20/0x2c | [<ffffffff80536dba>] m_can_start_xmit+0x90/0x34a | [<ffffffff806148b0>] dev_hard_start_xmit+0xa6/0xee | [<ffffffff8065b730>] sch_direct_xmit+0x114/0x292 | [<ffffffff80614e2a>] __dev_queue_xmit+0x3b0/0xaa8 | [<ffffffff8073b8fa>] can_send+0xc6/0x242 | [<ffffffff8073d1c0>] raw_sendmsg+0x1a8/0x36c | [<ffffffff805ebf06>] sock_write_iter+0x9a/0xee | [<ffffffff801d06ea>] vfs_write+0x184/0x3a6 | [<ffffffff801d0a88>] ksys_write+0xa0/0xc0 | [<ffffffff801d0abc>] __riscv_sys_write+0x14/0x1c | [<ffffffff8079ebf8>] do_trap_ecall_u+0x168/0x212 | [<ffffffff807a830a>] handle_exception+0x146/0x152 Initializing the spin lock in m_can_class_allocate_dev solves that problem. Fixes: 1fa80e23c150 ("can: m_can: Introduce a tx_fifo_in_flight counter") Signed-off-by: Antonios Salios <antonios@mwa.re> Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://patch.msgid.link/20250425111744.37604-2-antonios@mwa.re Reviewed-by: Markus Schneider-Pargmann <msp@baylibre.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2025-05-06block: move wbt_enable_default() out of queue freezing from sched ->exit()Ming Lei
scheduler's ->exit() is called with queue frozen and elevator lock is held, and wbt_enable_default() can't be called with queue frozen, otherwise the following lockdep warning is triggered: #6 (&q->rq_qos_mutex){+.+.}-{4:4}: #5 (&eq->sysfs_lock){+.+.}-{4:4}: #4 (&q->elevator_lock){+.+.}-{4:4}: #3 (&q->q_usage_counter(io)#3){++++}-{0:0}: #2 (fs_reclaim){+.+.}-{0:0}: #1 (&sb->s_type->i_mutex_key#3){+.+.}-{4:4}: #0 (&q->debugfs_mutex){+.+.}-{4:4}: Fix the issue by moving wbt_enable_default() out of bfq's exit(), and call it from elevator_change_done(). Meantime add disk->rqos_state_mutex for covering wbt state change, which matches the purpose more than ->elevator_lock. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250505141805.2751237-26-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: move hctx cpuhp add/del out of queue freezingMing Lei
Move hctx cpuhp add/del out of queue freezing for not connecting freeze lock with cpuhp locks, then lockdep warning can be avoided. This way is safe because both needn't queue to be frozen and scheduler switch isn't allowed, with same reason for moving hctx debugfs/sysfs register out of queue freeze. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250505141805.2751237-25-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: don't acquire ->elevator_lock in blk_mq_map_swqueue and ↵Ming Lei
blk_mq_realloc_hw_ctxs Both blk_mq_map_swqueue() and blk_mq_realloc_hw_ctxs() are called before the request queue is added to tagset list, so the two won't run concurrently with blk_mq_update_nr_hw_queues(). When the two functions are only called from queue initialization or blk_mq_update_nr_hw_queues(), elevator switch can't happen. So remove ->elevator_lock uses from the two functions. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250505141805.2751237-24-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: move hctx debugfs/sysfs registering out of freezing queueMing Lei
Move hctx debugfs/sysfs register out of freezing queue in __blk_mq_update_nr_hw_queues(), so that the following lockdep dependency can be killed: #2 (&q->q_usage_counter(io)#16){++++}-{0:0}: #1 (fs_reclaim){+.+.}-{0:0}: #0 (&sb->s_type->i_mutex_key#3){+.+.}-{4:4}: //debugfs And registering/un-registering hctx debugfs/sysfs does not require queue to be frozen: - hctx sysfs attributes show() are drained when removing kobject, and there isn't store() implementation for hctx sysfs attributes - debugfs entry read() is drained too when removing debugfs directory, and there isn't write() implementation for hctx debugfs too - so it is safe to register/unregister hctx sysfs/debugfs without freezing queue because the cod paths changes nothing, and we just need to keep hctx live Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-23-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: move elv_register[unregister]_queue out of elevator_lockMing Lei
Move elv_register[unregister]_queue out of ->elevator_lock & queue freezing, so we can kill many lockdep warnings. elv_register[unregister]_queue() is serialized, and just dealing with sysfs/ debugfs things, no need to be done with queue frozen: - when it is called from adding disk, elevator switch isn't possible because ->queue_kobj isn't added yet - when it is called from deleting disk, disable_elv_switch() is responsible for preventing new elevator switch and draining old elevator switch. - when it is called from blk_mq_update_nr_hw_queues(), adding/removing disk and elevator switch can't be allowed or in-progress With this change, elevator's ->exit() is called before calling elv_unregister_queue, then user may call into ->show()/store() of elevator's sysfs attributes, and we have covered this issue by adding `ELEVATOR_FLAG_DYNG`. For blk-mq debugfs, hctx->sched_tags is always checked with ->elevator_lock by debugfs code, meantime hctx->sched_tags is updated with ->elevator_lock, so there isn't such issue. Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250505141805.2751237-22-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: add new helper for disabling elevator switch when deleting diskMing Lei
Add new helper disable_elv_switch() and new flag QUEUE_FLAG_NO_ELV_SWITCH for disabling elevator switch before deleting disk: - originally flag QUEUE_FLAG_REGISTERED is added for preventing elevator switch during removing disk, but this flag has been used widely for other purposes, so add one new flag for disabling elevator switch only - for avoiding deadlock risk, we have to move elevator queue register/unregister out of elevator lock and queue freeze, which will be done in next patch. However, this way adds small race window between elevator switch and deleting ->queue_kobj, in which elevator queue register/unregister could be run concurrently. The added helper will be used for avoiding the race in the following patch. - drain in-progress elevator switch before deleting disk Suggested-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Link: https://lore.kernel.org/r/20250505141805.2751237-21-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: fail to show/store elevator sysfs attribute if elevator is dyingMing Lei
Prepare for moving elv_register[unregister]_queue out of elevator_lock & queue freezing, so we may have to call elv_unregister_queue() after elevator ->exit() is called, then there is small window for user to call into ->show()/store(), and user-after-free can be caused. Fail to show/store elevator sysfs attribute if elevator is dying by adding one new flag of ELEVATOR_FLAG_DYNG, which is protected by elevator ->sysfs_lock. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20250505141805.2751237-20-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: remove elevator queue's type check in elv_attr_show/store()Ming Lei
elevatore queue's type is assigned since its allocation, and never get cleared until it is released. So its ->type is always not NULL, remove the unnecessary check. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-19-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: pass elevator_queue to elv_register_queue & unregister_queueMing Lei
Pass elevator_queue reference to elv_register_queue() & elv_unregister_queue(). No functional change, and prepare for moving the two out of elevator lock & freezing queue, when we need to store the old & new elevator queue in `struct elv_change_ctx` instance, then both two can co-exist for short while, so we have to pass the exact elevator_queue instance to elv_register_queue & unregister_queue. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-18-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: unifying elevator changeMing Lei
Elevator change is one well-define behavior: - tear down current elevator if it exists - setup new elevator It is supposed to cover any case for changing elevator by single internal API, typically the following cases: - setup default elevator in add_disk() - switch to none in del_disk() - reset elevator in blk_mq_update_nr_hw_queues() - switch elevator in sysfs `store` elevator attribute This patch uses elevator_change() to cover all above cases: - every elevator switch is serialized with each other: add_disk/del_disk/ store elevator is serialized already, blk_mq_update_nr_hw_queues() uses srcu for syncing with the other three cases - for both add_disk()/del_disk(), queue freeze works at atomic mode or has been froze, so the freeze in elevator_change() won't add extra delay - `struct elev_change_ctx` instance holds any info for changing elevator Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-17-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: add `struct elv_change_ctx` for unifying elevator changeMing Lei
Add `struct elv_change_ctx` and prepare for unifying elevator change by elevator_change(). With this way, any input & output parameter can be provided & observed in top helper. This way helps to move kobject add/delete & debugfs register/unregister out of ->elevator_lock & freezing queue. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250505141805.2751237-16-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: move queue freezing & elevator_lock into elevator_change()Ming Lei
Move queue freezing & elevator_lock into elevator_change(), and prepare for using elevator_change() for setting up & tearing down default elevator too. Also add lockdep_assert_held() in __elevator_change() because either read or write lock is required for changing elevator. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-15-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: simplify elevator reattachment for updating nr_hw_queuesMing Lei
In blk_mq_update_nr_hw_queues(), nr_hw_queues changes and elevator data depends on it, and elevator has to be reattached, so call elevator_switch() to force attachment. Add elv_update_nr_hw_queues() simply for blk_mq_update_nr_hw_queues() to reattach elevator, since elevator switch isn't likely when running blk_mq_update_nr_hw_queues(). This way removes the current switch none and switch back code. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-14-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: move blk_queue_registered() check into elv_iosched_store()Ming Lei
Move blk_queue_registered() check into elv_iosched_store() and prepare for using elevator_change() for covering any kind of elevator change in adding/deleting disk and updating nr_hw_queue. Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250505141805.2751237-13-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: fold elevator_disable into elevator_switchChristoph Hellwig
This removes duplicate code, and keeps the callers tidy. Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-12-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: look up the elevator type in elevator_switchChristoph Hellwig
That makes the function nicely self-contained and can be used to avoid code duplication. Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-11-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: don't allow to switch elevator if updating nr_hw_queues is in-progressMing Lei
Elevator switch code is another `nr_hw_queue` reader in non-fast-IO code path, so it can't be done if updating `nr_hw_queues` is in-progress. Take same approach with not allowing add/del disk when updating nr_hw_queues is in-progress, by grabbing read lock of set->update_nr_hwq_sema. Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/linux-block/aAWv3NPtNIKKvJZc@fedora/ [1] Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Closes: https://lore.kernel.org/linux-block/mz4t4tlwiqjijw3zvqnjb7ovvvaegkqganegmmlc567tt5xj67@xal5ro544cnc/ Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250505141805.2751237-10-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: prevent adding/deleting disk during updating nr_hw_queuesMing Lei
Both adding/deleting disk code are reader of `nr_hw_queues`, so we can't allow them in-progress when updating nr_hw_queues, kernel panic and kasan has been reported in [1]. Prevent adding/deleting disk during updating nr_hw_queues by adding rw_semaphore to tagset, write lock is grabbed in blk_mq_update_nr_hw_queues(), and read lock is acquired when adding/deleting disk. Also mark GFP_NOIO allocation scope for adding/deleting disk because blk_mq_update_nr_hw_queues() is part of some driver's error handler. This way avoids lot of trouble. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Suggested-by: Nilay Shroff <nilay@linux.ibm.com> Reported-by: Nilay Shroff <nilay@linux.ibm.com> Closes: https://lore.kernel.org/linux-block/a5896cdb-a59a-4a37-9f99-20522f5d2987@linux.ibm.com/ Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-9-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: add helper add_disk_final()Ming Lei
Add helper add_disk_final() for scanning partitions, announcing disk and handling the last thing for adding disk. No functional change, and prepare for prevent adding disk from happening when updating nr_hw_queues. Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250505141805.2751237-8-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: move sched debugfs register into elvevator_register_queueMing Lei
sched debugfs shares same lifetime with scheduler's kobject, and same lock(elevator lock), so move sched debugfs register/unregister into elevator_register_queue() and elevator_unregister_queue(). Then we needn't blk_mq_debugfs_register() for us to register sched debugfs any more. Reviewed-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-7-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: add two helpers for registering/un-registering sched debugfsMing Lei
Add blk_mq_sched_reg_debugfs()/blk_mq_sched_unreg_debugfs() to clean up sched init/exit code a bit. Register & unregister debugfs for sched & sched_hctx order is changed a bit, but it is safe because sched & sched_hctx is guaranteed to be ready when exporting via debugfs. Reviewed-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-6-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: use q->elevator with ->elevator_lock held in elv_iosched_show()Ming Lei
Use q->elevator with ->elevator_lock held in elv_iosched_show(), since the local cached elevator reference may become stale after getting ->elevator_lock. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-5-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: don't call freeze queue in elevator_switch() and elevator_disable()Ming Lei
Both elevator_switch() and elevator_disable() are only called from the two code paths, in which queue is guaranteed to be frozen. So don't call freeze queue in the two functions, also add asserts for queue freeze. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20250505141805.2751237-4-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: move ELEVATOR_FLAG_DISABLE_WBT a request queue flagMing Lei
ELEVATOR_FLAG_DISABLE_WBT is only used by BFQ to disallow wbt when BFQ is in use. The flag is set in BFQ's init(), and cleared in BFQ's exit(). Making it as request queue flag, so that we can avoid to deal with elevator switch race. Also it isn't graceful to checking one scheduler flag in wbt_enable_default(). Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-3-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06block: move blk_mq_add_queue_tag_set() after blk_mq_map_swqueue()Ming Lei
Move blk_mq_add_queue_tag_set() after blk_mq_map_swqueue(), and publish this request queue to tagset after everything is setup. This way is safe because BLK_MQ_F_TAG_QUEUE_SHARED isn't used by blk_mq_map_swqueue(), and this flag is mainly checked in fast IO code path. Prepare for removing ->elevator_lock from blk_mq_map_swqueue() which is supposed to be called when elevator switch can't be done. Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reported-by: Nilay Shroff <nilay@linux.ibm.com> Closes: https://lore.kernel.org/linux-block/567cb7ab-23d6-4cee-a915-c8cdac903ddd@linux.ibm.com/ Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250505141805.2751237-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06brd: fix discard end sectorYu Kuai
brd_do_discard() just aligned start sector to page, this can only work if the discard size if at least one page. For example: blkdiscard /dev/ram0 -o 5120 -l 1024 In this case, size = (1024 - (8192 - 5120)), which is a huge value. Fix the problem by round_down() the end sector. Fixes: 9ead7efc6f3f ("brd: implement discard support") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250506061756.2970934-4-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06brd: fix aligned_sector from brd_do_discard()Yu Kuai
The calculation is just wrong, fix it by round_up(). Fixes: 9ead7efc6f3f ("brd: implement discard support") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250506061756.2970934-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>