kernel/linux.git/drivers/target/loopback, branch v6.6.134

scsi: target: tcm_loop: Drain commands in target_reset handler

2026-04-11T12:19:35+00:00

[ Upstream commit 1333eee56cdf3f0cf67c6ab4114c2c9e0a952026 ] tcm_loop_target_reset() violates the SCSI EH contract: it returns SUCCESS without draining any in-flight commands. The SCSI EH documentation (scsi_eh.rst) requires that when a reset handler returns SUCCESS the driver has made lower layers "forget about timed out scmds" and is ready for new commands. Every other SCSI LLD (virtio_scsi, mpt3sas, ipr, scsi_debug, mpi3mr) enforces this by draining or completing outstanding commands before returning SUCCESS. Because tcm_loop_target_reset() doesn't drain, the SCSI EH reuses in-flight scsi_cmnd structures for recovery commands (e.g. TUR) while the target core still has async completion work queued for the old se_cmd. The memset in queuecommand zeroes se_lun and lun_ref_active, causing transport_lun_remove_cmd() to skip its percpu_ref_put(). The leaked LUN reference prevents transport_clear_lun_ref() from completing, hanging configfs LUN unlink forever in D-state: INFO: task rm:264 blocked for more than 122 seconds. rm D 0 264 258 0x00004000 Call Trace: __schedule+0x3d0/0x8e0 schedule+0x36/0xf0 transport_clear_lun_ref+0x78/0x90 [target_core_mod] core_tpg_remove_lun+0x28/0xb0 [target_core_mod] target_fabric_port_unlink+0x50/0x60 [target_core_mod] configfs_unlink+0x156/0x1f0 [configfs] vfs_unlink+0x109/0x290 do_unlinkat+0x1d5/0x2d0 Fix this by making tcm_loop_target_reset() actually drain commands: 1. Issue TMR_LUN_RESET via tcm_loop_issue_tmr() to drain all commands that the target core knows about (those not yet CMD_T_COMPLETE). 2. Use blk_mq_tagset_busy_iter() to iterate all started requests and flush_work() on each se_cmd — this drains any deferred completion work for commands that already had CMD_T_COMPLETE set before the TMR (which the TMR skips via __target_check_io_state()). This is the same pattern used by mpi3mr, scsi_debug, and libsas to drain outstanding commands during reset. Fixes: e0eb5d38b732 ("scsi: target: tcm_loop: Use block cmd allocator for se_cmds") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Josef Bacik Link: https://patch.msgid.link/27011aa34c8f6b1b94d2e3cf5655b6d037f53428.1773706803.git.josef@toxicpanda.com Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

scsi: target: tcm_loop: Fix segfault in tcm_loop_tpg_address_show()

2025-12-01T10:41:42+00:00

commit e6965188f84a7883e6a0d3448e86b0cf29b24dfc upstream. If the allocation of tl_hba->sh fails in tcm_loop_driver_probe() and we attempt to dereference it in tcm_loop_tpg_address_show() we will get a segfault, see below for an example. So, check tl_hba->sh before dereferencing it. Unable to allocate struct scsi_host BUG: kernel NULL pointer dereference, address: 0000000000000194 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 8356 Comm: tokio-runtime-w Not tainted 6.6.104.2-4.azl3 #1 Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 09/28/2024 RIP: 0010:tcm_loop_tpg_address_show+0x2e/0x50 [tcm_loop] ... Call Trace: configfs_read_iter+0x12d/0x1d0 [configfs] vfs_read+0x1b5/0x300 ksys_read+0x6f/0xf0 ... Cc: stable@vger.kernel.org Fixes: 2628b352c3d4 ("tcm_loop: Show address of tpg in configfs") Signed-off-by: Hamza Mahfooz Reviewed-by: Chaitanya Kulkarni Reviewed-by: Allen Pais Link: https://patch.msgid.link/1762370746-6304-1-git-send-email-hamzamahfooz@linux.microsoft.com Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

scsi: target: tcm_loop: Remove redundant driver match function

2023-03-25T00:44:14+00:00

If there is no driver match function, the driver core assumes that each candidate pair (driver, device) matches. See driver_match_device(). pseudo_lld_bus_match() always returns 1 and is therefore equivalent to not registering a match function. Remove it. Signed-off-by: Lizhe Link: https://lore.kernel.org/r/20230319043518.297490-1-sensor1010@163.com Signed-off-by: Martin K. Petersen

Merge patch series "Constify most SCSI host templates"

2023-03-25T00:13:03+00:00

Bart Van Assche says: It helps humans and the compiler if it is made explicit that SCSI host templates are not modified. Hence this patch series that constifies most SCSI host templates. Please consider this patch series for the next merge window. Link: https://lore.kernel.org/r/20230322195515.1267197-1-bvanassche@acm.org Signed-off-by: Martin K. Petersen

scsi: target: tcm-loop: Declare SCSI host template const

2023-03-24T23:20:00+00:00

Make it explicit that the SCSI host template is not modified. Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20230322195515.1267197-79-bvanassche@acm.org Signed-off-by: Martin K. Petersen

scsi: target: loop: Remove default fabric ops callouts

2023-03-17T03:36:36+00:00

Remove callouts that are identical to the default implementations in TCM Core. Signed-off-by: Dmitry Bogdanov Link: https://lore.kernel.org/r/20230313181110.20566-5-d.bogdanov@yadro.com Signed-off-by: Martin K. Petersen

scsi: target: tcm_loop: Fix possible name leak in tcm_loop_setup_hba_bus()

2022-11-17T17:46:16+00:00

If device_register() fails in tcm_loop_setup_hba_bus(), the name allocated by dev_set_name() need be freed. As comment of device_register() says, it should use put_device() to give up the reference in the error path. So fix this by calling put_device(), then the name can be freed in kobject_cleanup(). The 'tl_hba' will be freed in tcm_loop_release_adapter(), so it don't need goto error label in this case. Fixes: 3703b2c5d041 ("[SCSI] tcm_loop: Add multi-fabric Linux/SCSI LLD fabric module") Signed-off-by: Yang Yingliang Link: https://lore.kernel.org/r/20221115015042.3652261-1-yangyingliang@huawei.com Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen

scsi: target: tcm_loop: Call scsi_done() directly

2021-10-17T01:31:43+00:00

Conditional statements are faster than indirect calls. Hence call scsi_done() directly. Link: https://lore.kernel.org/r/20211007204618.2196847-9-bvanassche@acm.org Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2021-09-02T22:09:46+00:00

Pull SCSI updates from James Bottomley: "This series consists of the usual driver updates (ufs, qla2xxx, target, smartpqi, lpfc, mpt3sas). The core change causing the most churn was replacing the command request field request with a macro, allowing us to offset map to it and remove the redundant field; the same was also done for the tag field. The most impactful change is the final removal of scsi_ioctl, which has been deprecated for over a decade" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (293 commits) scsi: ufs: Fix ufshcd_request_sense_async() for Samsung KLUFG8RHDA-B2D1 scsi: ufs: ufs-exynos: Fix static checker warning scsi: mpt3sas: Use the proper SCSI midlayer interfaces for PI scsi: lpfc: Use the proper SCSI midlayer interfaces for PI scsi: lpfc: Copyright updates for 14.0.0.1 patches scsi: lpfc: Update lpfc version to 14.0.0.1 scsi: lpfc: Add bsg support for retrieving adapter cmf data scsi: lpfc: Add cmf_info sysfs entry scsi: lpfc: Add debugfs support for cm framework buffers scsi: lpfc: Add support for maintaining the cm statistics buffer scsi: lpfc: Add rx monitoring statistics scsi: lpfc: Add support for the CM framework scsi: lpfc: Add cmfsync WQE support scsi: lpfc: Add support for cm enablement buffer scsi: lpfc: Add cm statistics buffer support scsi: lpfc: Add EDC ELS support scsi: lpfc: Expand FPIN and RDF receive logging scsi: lpfc: Add MIB feature enablement support scsi: lpfc: Add SET_HOST_DATA mbox cmd to pass date/time info to firmware scsi: fc: Add EDC ELS definition ...

scsi: tcm_loop: Use scsi_cmd_to_rq() instead of scsi_cmnd.request

2021-08-12T02:25:42+00:00

Prepare for removal of the request pointer by using scsi_cmd_to_rq() instead. This patch does not change any functionality. Link: https://lore.kernel.org/r/20210809230355.8186-51-bvanassche@acm.org Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen