user/sven/linux.git/include/target, branch v5.4.193

scsi: target: Fix ordered tag handling

2021-11-26T09:47:16Z

[ 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 cmd length set before cmd complete

2021-03-17T16:03:45Z

[ Upstream commit 1c73e0c5e54d5f7d77f422a10b03ebe61eaed5ad ] TCM doesn't properly handle underflow case for service actions. One way to prevent it is to always complete command with target_complete_cmd_with_length(), however it requires access to data_sg, which is not always available. This change introduces target_set_cmd_data_length() function which allows to set command data length before completing it. Link: https://lore.kernel.org/r/20210209072202.41154-2-a.miloserdov@yadro.com Reviewed-by: Roman Bolshakov Reviewed-by: Bodo Stroesser Signed-off-by: Aleksandr Miloserdov Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target: fix hang when multiple threads try to destroy the same iscsi session

2020-04-21T07:05:04Z

[ Upstream commit 57c46e9f33da530a2485fa01aa27b6d18c28c796 ] A number of hangs have been reported against the target driver; they are due to the fact that multiple threads may try to destroy the iscsi session at the same time. This may be reproduced for example when a "targetcli iscsi/iqn.../tpg1 disable" command is executed while a logout operation is underway. When this happens, two or more threads may end up sleeping and waiting for iscsit_close_connection() to execute "complete(session_wait_comp)". Only one of the threads will wake up and proceed to destroy the session structure, the remaining threads will hang forever. Note that if the blocked threads are somehow forced to wake up with complete_all(), they will try to free the same iscsi session structure destroyed by the first thread, causing double frees, memory corruptions etc... With this patch, the threads that want to destroy the iscsi session will increase the session refcount and will set the "session_close" flag to 1; then they wait for the driver to close the remaining active connections. When the last connection is closed, iscsit_close_connection() will wake up all the threads and will wait for the session's refcount to reach zero; when this happens, iscsit_close_connection() will destroy the session structure because no one is referencing it anymore. INFO: task targetcli:5971 blocked for more than 120 seconds. Tainted: P OE 4.15.0-72-generic #81~16.04.1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. targetcli D 0 5971 1 0x00000080 Call Trace: __schedule+0x3d6/0x8b0 ? vprintk_func+0x44/0xe0 schedule+0x36/0x80 schedule_timeout+0x1db/0x370 ? __dynamic_pr_debug+0x8a/0xb0 wait_for_completion+0xb4/0x140 ? wake_up_q+0x70/0x70 iscsit_free_session+0x13d/0x1a0 [iscsi_target_mod] iscsit_release_sessions_for_tpg+0x16b/0x1e0 [iscsi_target_mod] iscsit_tpg_disable_portal_group+0xca/0x1c0 [iscsi_target_mod] lio_target_tpg_enable_store+0x66/0xe0 [iscsi_target_mod] configfs_write_file+0xb9/0x120 __vfs_write+0x1b/0x40 vfs_write+0xb8/0x1b0 SyS_write+0x5c/0xe0 do_syscall_64+0x73/0x130 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Link: https://lore.kernel.org/r/20200313170656.9716-3-mlombard@redhat.com Reported-by: Matt Coleman Tested-by: Matt Coleman Tested-by: Rahul Kundu Signed-off-by: Maurizio Lombardi Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target/iscsi: Handle too large immediate data buffers correctly

2019-04-13T00:20:06Z

Since target_alloc_sgl() and iscsit_allocate_iovecs() allocate buffer space for se_cmd.data_length bytes and since that number can be smaller than the iSCSI Expected Data Transfer Length (EDTL), ensure that the iSCSI target driver does not attempt to receive more bytes than what fits in the receive buffer. Always receive the full immediate data buffer such that the iSCSI target driver does not attempt to parse immediate data as an iSCSI PDU. Note: the current code base only calls iscsit_get_dataout() if the size of the immediate data buffer does not exceed the buffer size derived from the SCSI CDB. See also target_cmd_size_check(). Cc: Mike Christie Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Nicholas Bellinger Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: target/core: Rework the SPC-2 reservation handling code

2019-04-13T00:20:05Z

Instead of tracking the initiator that established an SPC-2 reservation, track the session through which the SPC-2 reservation has been established. This patch does not change any functionality. Cc: Mike Christie Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Nicholas Bellinger Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: target/iscsi: Rename a function and a function pointer

2019-02-05T02:34:49Z

Having both a function and a function pointer member with the same name (iscsit_release_cmd) is confusing. Hence rename the function pointer member. Cc: Nicholas Bellinger Cc: Mike Christie Cc: Christoph Hellwig Cc: Hannes Reinecke Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: target/iscsi: Fix spelling of "unsolicited"

2019-02-05T02:33:59Z

Change "unsoliticed" into "unsolicited". Cc: Nicholas Bellinger Cc: Mike Christie Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Sagi Grimberg Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: target/core: Add target_send_busy()

2019-02-05T02:28:48Z

Introduce a function that sends the SCSI status "BUSY" back to the initiator. The next patch will add a call to this function in the srpt target driver. Reviewed-by: Hannes Reinecke Cc: Nicholas Bellinger Cc: Mike Christie Cc: Christoph Hellwig Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: target/core: Remove several state tests from the TMF code

2019-02-05T02:25:13Z

Whether or not a session is being torn down does not affect whether or not SCSI commands are in the task set. Hence remove the "tearing down" checks from the TMF code. The TRANSPORT_ISTATE_PROCESSING check is left out because it is now safe to wait for a command that is in that state. The CMD_T_PRE_EXECUTE is left out because abort processing is postponed until after commands have left the pre-execute state since the patch that makes TMF processing synchronous. See also commit 1c21a48055a6 ("target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASK"). Cc: Nicholas Bellinger Cc: Mike Christie Cc: Christoph Hellwig Cc: Hannes Reinecke Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: target/core: Remove the write_pending_status() callback function

2019-02-05T02:23:59Z

Due to the patch that makes TMF handling synchronous the write_pending_status() callback function is no longer called. Hence remove it. Acked-by: Felipe Balbi Reviewed-by: Sagi Grimberg Reviewed-by: Andy Grover Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Bryant G. Ly Cc: Nicholas Bellinger Cc: Mike Christie Cc: Himanshu Madhani Cc: Quinn Tran Cc: Saurav Kashyap Cc: Michael S. Tsirkin Cc: Juergen Gross Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen