kernel/linux.git/drivers/target/target_core_device.c, branch v5.15.208

scsi: target: core: Fix null-ptr-deref in target_alloc_device()

2024-11-01T00:52:34+00:00

[ Upstream commit fca6caeb4a61d240f031914413fcc69534f6dc03 ] There is a null-ptr-deref issue reported by KASAN: BUG: KASAN: null-ptr-deref in target_alloc_device+0xbc4/0xbe0 [target_core_mod] ... kasan_report+0xb9/0xf0 target_alloc_device+0xbc4/0xbe0 [target_core_mod] core_dev_setup_virtual_lun0+0xef/0x1f0 [target_core_mod] target_core_init_configfs+0x205/0x420 [target_core_mod] do_one_initcall+0xdd/0x4e0 ... entry_SYSCALL_64_after_hwframe+0x76/0x7e In target_alloc_device(), if allocing memory for dev queues fails, then dev will be freed by dev->transport->free_device(), but dev->transport is not initialized at that time, which will lead to a null pointer reference problem. Fixing this bug by freeing dev with hba->backend->ops->free_device(). Fixes: 1526d9f10c61 ("scsi: target: Make state_list per CPU") Signed-off-by: Wang Hai Link: https://lore.kernel.org/r/20241011113444.40749-1-wanghai38@huawei.com Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target: core: Add TMF to tmr_list handling

2024-03-01T12:21:43+00:00

[ Upstream commit 83ab68168a3d990d5ff39ab030ad5754cbbccb25 ] An abort that is responded to by iSCSI itself is added to tmr_list but does not go to target core. A LUN_RESET that goes through tmr_list takes a refcounter on the abort and waits for completion. However, the abort will be never complete because it was not started in target core. Unable to locate ITT: 0x05000000 on CID: 0 Unable to locate RefTaskTag: 0x05000000 on CID: 0. wait_for_tasks: Stopping tmf LUN_RESET with tag 0x0 ref_task_tag 0x0 i_state 34 t_state ISTATE_PROCESSING refcnt 2 transport_state active,stop,fabric_stop wait for tasks: tmf LUN_RESET with tag 0x0 ref_task_tag 0x0 i_state 34 t_state ISTATE_PROCESSING refcnt 2 transport_state active,stop,fabric_stop ... INFO: task kworker/0:2:49 blocked for more than 491 seconds. task:kworker/0:2 state:D stack: 0 pid: 49 ppid: 2 flags:0x00000800 Workqueue: events target_tmr_work [target_core_mod] Call Trace: __switch_to+0x2c4/0x470 _schedule+0x314/0x1730 schedule+0x64/0x130 schedule_timeout+0x168/0x430 wait_for_completion+0x140/0x270 target_put_cmd_and_wait+0x64/0xb0 [target_core_mod] core_tmr_lun_reset+0x30/0xa0 [target_core_mod] target_tmr_work+0xc8/0x1b0 [target_core_mod] process_one_work+0x2d4/0x5d0 worker_thread+0x78/0x6c0 To fix this, only add abort to tmr_list if it will be handled by target core. Signed-off-by: Dmitry Bogdanov Link: https://lore.kernel.org/r/20240111125941.8688-1-d.bogdanov@yadro.com Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target: core: Fix deadlock due to recursive locking

2023-10-10T19:59:07+00:00

[ Upstream commit a154f5f643c6ecddd44847217a7a3845b4350003 ] The following call trace shows a deadlock issue due to recursive locking of mutex "device_mutex". First lock acquire is in target_for_each_device() and second in target_free_device(). PID: 148266 TASK: ffff8be21ffb5d00 CPU: 10 COMMAND: "iscsi_ttx" #0 [ffffa2bfc9ec3b18] __schedule at ffffffffa8060e7f #1 [ffffa2bfc9ec3ba0] schedule at ffffffffa8061224 #2 [ffffa2bfc9ec3bb8] schedule_preempt_disabled at ffffffffa80615ee #3 [ffffa2bfc9ec3bc8] __mutex_lock at ffffffffa8062fd7 #4 [ffffa2bfc9ec3c40] __mutex_lock_slowpath at ffffffffa80631d3 #5 [ffffa2bfc9ec3c50] mutex_lock at ffffffffa806320c #6 [ffffa2bfc9ec3c68] target_free_device at ffffffffc0935998 [target_core_mod] #7 [ffffa2bfc9ec3c90] target_core_dev_release at ffffffffc092f975 [target_core_mod] #8 [ffffa2bfc9ec3ca0] config_item_put at ffffffffa79d250f #9 [ffffa2bfc9ec3cd0] config_item_put at ffffffffa79d2583 #10 [ffffa2bfc9ec3ce0] target_devices_idr_iter at ffffffffc0933f3a [target_core_mod] #11 [ffffa2bfc9ec3d00] idr_for_each at ffffffffa803f6fc #12 [ffffa2bfc9ec3d60] target_for_each_device at ffffffffc0935670 [target_core_mod] #13 [ffffa2bfc9ec3d98] transport_deregister_session at ffffffffc0946408 [target_core_mod] #14 [ffffa2bfc9ec3dc8] iscsit_close_session at ffffffffc09a44a6 [iscsi_target_mod] #15 [ffffa2bfc9ec3df0] iscsit_close_connection at ffffffffc09a4a88 [iscsi_target_mod] #16 [ffffa2bfc9ec3df8] finish_task_switch at ffffffffa76e5d07 #17 [ffffa2bfc9ec3e78] iscsit_take_action_for_connection_exit at ffffffffc0991c23 [iscsi_target_mod] #18 [ffffa2bfc9ec3ea0] iscsi_target_tx_thread at ffffffffc09a403b [iscsi_target_mod] #19 [ffffa2bfc9ec3f08] kthread at ffffffffa76d8080 #20 [ffffa2bfc9ec3f50] ret_from_fork at ffffffffa8200364 Fixes: 36d4cb460bcb ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion") Signed-off-by: Junxiao Bi Link: https://lore.kernel.org/r/20230918225848.66463-1-junxiao.bi@oracle.com Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target: Fix multiple LUN_RESET handling

2023-05-11T14:00:26+00:00

[ Upstream commit 673db054d7a2b5a470d7a25baf65956d005ad729 ] This fixes a bug where an initiator thinks a LUN_RESET has cleaned up running commands when it hasn't. The bug was added in commit 51ec502a3266 ("target: Delete tmr from list before processing"). The problem occurs when: 1. We have N I/O cmds running in the target layer spread over 2 sessions. 2. The initiator sends a LUN_RESET for each session. 3. session1's LUN_RESET loops over all the running commands from both sessions and moves them to its local drain_task_list. 4. session2's LUN_RESET does not see the LUN_RESET from session1 because the commit above has it remove itself. session2 also does not see any commands since the other reset moved them off the state lists. 5. sessions2's LUN_RESET will then complete with a successful response. 6. sessions2's inititor believes the running commands on its session are now cleaned up due to the successful response and cleans up the running commands from its side. It then restarts them. 7. The commands do eventually complete on the backend and the target starts to return aborted task statuses for them. The initiator will either throw a invalid ITT error or might accidentally lookup a new task if the ITT has been reallocated already. Fix the bug by reverting the patch, and serialize the execution of LUN_RESETs and Preempt and Aborts. Also prevent us from waiting on LUN_RESETs in core_tmr_drain_tmr_list, because it turns out the original patch fixed a bug that was not mentioned. For LUN_RESET1 core_tmr_drain_tmr_list can see a second LUN_RESET and wait on it. Then the second reset will run core_tmr_drain_tmr_list and see the first reset and wait on it resulting in a deadlock. Fixes: 51ec502a3266 ("target: Delete tmr from list before processing") Signed-off-by: Mike Christie Link: https://lore.kernel.org/r/20230319015620.96006-8-michael.christie@oracle.com Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

target: remove an incorrect unmap zeroes data deduction

2022-06-09T08:22:47+00:00

[ Upstream commit 179d8609d8424529e95021df939ed7b0b82b37f1 ] For block devices, the SCSI target drivers implements UNMAP as calls to blkdev_issue_discard, which does not guarantee zeroing just because Write Zeroes is supported. Note that this does not affect the file backed path which uses fallocate to punch holes. Fixes: 2237498f0b5c ("target/iblock: Convert WRITE_SAME to blkdev_issue_zeroout") Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20220415045258.199825-2-hch@lst.de Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

scsi: target: Fix ordered tag handling

2021-11-25T08:48:29+00:00

[ Upstream commit ed1227e080990ffec5bf39006ec8a57358e6689a ] This patch fixes the following bugs: 1. If there are multiple ordered cmds queued and multiple simple cmds completing, target_restart_delayed_cmds() could be called on different CPUs and each instance could start a ordered cmd. They could then run in different orders than they were queued. 2. target_restart_delayed_cmds() and target_handle_task_attr() can race where: 1. target_handle_task_attr() has passed the simple_cmds == 0 check. 2. transport_complete_task_attr() then decrements simple_cmds to 0. 3. transport_complete_task_attr() runs target_restart_delayed_cmds() and it does not see any cmds on the delayed_cmd_list. 4. target_handle_task_attr() adds the cmd to the delayed_cmd_list. The cmd will then end up timing out. 3. If we are sent > 1 ordered cmds and simple_cmds == 0, we can execute them out of order, because target_handle_task_attr() will hit that simple_cmds check first and return false for all ordered cmds sent. 4. We run target_restart_delayed_cmds() after every cmd completion, so if there is more than 1 simple cmd running, we start executing ordered cmds after that first cmd instead of waiting for all of them to complete. 5. Ordered cmds are not supposed to start until HEAD OF QUEUE and all older cmds have completed, and not just simple. 6. It's not a bug but it doesn't make sense to take the delayed_cmd_lock for every cmd completion when ordered cmds are almost never used. Just replacing that lock with an atomic increases IOPs by up to 10% when completions are spread over multiple CPUs and there are multiple sessions/ mqs/thread accessing the same device. This patch moves the queued delayed handling to a per device work to serialze the cmd executions for each device and adds a new counter to track HEAD_OF_QUEUE and SIMPLE cmds. We can then check the new counter to determine when to run the work on the completion path. Link: https://lore.kernel.org/r/20210930020422.92578-3-michael.christie@oracle.com Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target: core: Add configurable IEEE Company ID attribute

2021-05-15T18:14:28+00:00

Implement an attribute which provides a way to set a company specific WWN in configfs via: target/core/$backstore/$name/wwn/company_id The Open Fabrics Alliance ID 001405h remains the default. Link: https://lore.kernel.org/r/20210420185920.42431-3-s.samoylenko@yadro.com Signed-off-by: Sergey Samoylenko Signed-off-by: Roman Bolshakov Signed-off-by: Martin K. Petersen

scsi: target: Make the virtual LUN 0 device

2021-04-06T03:26:39+00:00

Create the device for the virtual LUN 0 using the DUMMY flag. This change makes it possible to remove some special-casing in the INQUIRY code. Link: https://lore.kernel.org/r/20210322200938.53300-3-k.shelekhin@yadro.com Reviewed-by: Roman Bolshakov Reviewed-by: Mike Christie Signed-off-by: Konstantin Shelekhin Signed-off-by: Martin K. Petersen

scsi: target: core: Add workqueue based cmd submission

2021-03-04T22:37:02+00:00

loop and vhost/scsi do their target cmd submission from driver workqueues. This allows them to avoid an issue where the backend may block waiting for resources like tags/requests, mem/locks, etc and that ends up blocking their entire submission path and for the case of vhost-scsi both the submission and completion path. This patch adds a helper drivers can use to submit from a LIO workqueue. This code will then be extended in the next patches to fix the plugging of backend devices. We are only converting vhost/loop initially, but the workqueue based submission will work for other drivers and have similar benefits where the main target loops will not end up blocking one some backend resource. Link: https://lore.kernel.org/r/20210227170006.5077-17-michael.christie@oracle.com Tested-by: Laurence Oberman Reviewed-by: Bodo Stroesser Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen

scsi: target: Make state_list per CPU

2020-11-05T03:39:38+00:00

Do a state_list/execute_task_lock per CPU, so we can do submissions from different CPUs without contention with each other. Note: tcm_fc was passing TARGET_SCF_USE_CPUID, but never set cpuid. The assumption is that it wanted to set the cpuid to the CPU it was submitting from so it will get this behavior with this patch. [mkp: s/printk/pr_err/ + resolve COMPARE AND WRITE patch conflict] Link: https://lore.kernel.org/r/1604257174-4524-8-git-send-email-michael.christie@oracle.com Reviewed-by: Himanshu Madhani Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen