kernel/drivers/target/target_core_xcopy.c, branch linux-4.16.y

xcopy: loop over devices using idr helper

2017-07-07T06:11:40Z

This converts the xcopy code to use the idr helper. The next patch will drop the g_device_list and make g_device_mutex local to the target_core_device.c file. Signed-off-by: Mike Christie Reviewed-by: Bart Van Assche Signed-off-by: Nicholas Bellinger

target: Fix a deadlock between the XCOPY code and iSCSI session shutdown

2017-07-07T05:58:00Z

Move the code for parsing an XCOPY command from the context of the iSCSI receiver thread to the context of the XCOPY workqueue. Keep the simple XCOPY checks in the context of the iSCSI receiver thread. Move the code for allocating and freeing struct xcopy_op from the code that parses an XCOPY command to its caller. This patch fixes the following deadlock: ====================================================== [ INFO: possible circular locking dependency detected ] 4.10.0-rc7-dbg+ #1 Not tainted ------------------------------------------------------- rmdir/13321 is trying to acquire lock: (&sess->cmdsn_mutex){+.+.+.}, at: [] iscsit_free_all_ooo_cmdsns+0x2d/0xb0 [iscsi_target_mod] but task is already holding lock: (&sb->s_type->i_mutex_key#14){++++++}, at: [] vfs_rmdir+0x50/0x140 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#14){++++++}: lock_acquire+0x71/0x90 down_write+0x3f/0x70 configfs_depend_item+0x3a/0xb0 [configfs] target_depend_item+0x13/0x20 [target_core_mod] target_xcopy_locate_se_dev_e4+0xdd/0x1a0 [target_core_mod] target_do_xcopy+0x34b/0x970 [target_core_mod] __target_execute_cmd+0x22/0xa0 [target_core_mod] target_execute_cmd+0x233/0x2c0 [target_core_mod] iscsit_execute_cmd+0x208/0x270 [iscsi_target_mod] iscsit_sequence_cmd+0x10b/0x190 [iscsi_target_mod] iscsit_get_rx_pdu+0x37d/0xcd0 [iscsi_target_mod] iscsi_target_rx_thread+0x6e/0xa0 [iscsi_target_mod] kthread+0x102/0x140 ret_from_fork+0x31/0x40 -> #0 (&sess->cmdsn_mutex){+.+.+.}: __lock_acquire+0x10e6/0x1260 lock_acquire+0x71/0x90 mutex_lock_nested+0x5f/0x670 iscsit_free_all_ooo_cmdsns+0x2d/0xb0 [iscsi_target_mod] iscsit_close_session+0xac/0x200 [iscsi_target_mod] lio_tpg_close_session+0x9f/0xb0 [iscsi_target_mod] target_shutdown_sessions+0xc3/0xd0 [target_core_mod] core_tpg_del_initiator_node_acl+0x91/0x140 [target_core_mod] target_fabric_nacl_base_release+0x20/0x30 [target_core_mod] config_item_release+0x5a/0xc0 [configfs] config_item_put+0x1d/0x1f [configfs] configfs_rmdir+0x1a6/0x300 [configfs] vfs_rmdir+0xb7/0x140 do_rmdir+0x1f4/0x200 SyS_rmdir+0x11/0x20 entry_SYSCALL_64_fastpath+0x23/0xc6 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#14); lock(&sess->cmdsn_mutex); lock(&sb->s_type->i_mutex_key#14); lock(&sess->cmdsn_mutex); *** DEADLOCK *** 3 locks held by rmdir/13321: #0: (sb_writers#10){.+.+.+}, at: [] mnt_want_write+0x1f/0x50 #1: (&default_group_class[depth - 1]#2/1){+.+.+.}, at: [] do_rmdir+0x15e/0x200 #2: (&sb->s_type->i_mutex_key#14){++++++}, at: [] vfs_rmdir+0x50/0x140 stack backtrace: CPU: 2 PID: 13321 Comm: rmdir Not tainted 4.10.0-rc7-dbg+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 Call Trace: dump_stack+0x86/0xc3 print_circular_bug+0x1c7/0x220 __lock_acquire+0x10e6/0x1260 lock_acquire+0x71/0x90 mutex_lock_nested+0x5f/0x670 iscsit_free_all_ooo_cmdsns+0x2d/0xb0 [iscsi_target_mod] iscsit_close_session+0xac/0x200 [iscsi_target_mod] lio_tpg_close_session+0x9f/0xb0 [iscsi_target_mod] target_shutdown_sessions+0xc3/0xd0 [target_core_mod] core_tpg_del_initiator_node_acl+0x91/0x140 [target_core_mod] target_fabric_nacl_base_release+0x20/0x30 [target_core_mod] config_item_release+0x5a/0xc0 [configfs] config_item_put+0x1d/0x1f [configfs] configfs_rmdir+0x1a6/0x300 [configfs] vfs_rmdir+0xb7/0x140 do_rmdir+0x1f4/0x200 SyS_rmdir+0x11/0x20 entry_SYSCALL_64_fastpath+0x23/0xc6 Signed-off-by: Bart Van Assche Cc: Hannes Reinecke Cc: Christoph Hellwig Cc: Andy Grover Cc: David Disseldorp Signed-off-by: Nicholas Bellinger

target: Use {get,put}_unaligned_be*() instead of open coding these functions

2017-07-07T05:57:59Z

Introduce the function get_unaligned_be24(). Use {get,put}_unaligned_be*() where appropriate. This patch does not change any functionality. Signed-off-by: Bart Van Assche Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Cc: Andy Grover Cc: David Disseldorp Signed-off-by: Nicholas Bellinger

target: Use correct SCSI status during EXTENDED_COPY exception

2017-02-08T15:46:54Z

This patch adds the missing target_complete_cmd() SCSI status parameter change in target_xcopy_do_work(), that was originally missing in commit 926317de33. It correctly propigates up the correct SCSI status during EXTENDED_COPY exception cases, instead of always using the hardcoded SAM_STAT_CHECK_CONDITION from original code. This is required for ESX host environments that expect to hit SAM_STAT_RESERVATION_CONFLICT for certain scenarios, and SAM_STAT_CHECK_CONDITION results in non-retriable status for these cases. Reported-by: Nixon Vincent Tested-by: Nixon Vincent Cc: Nixon Vincent Reviewed-by: Christoph Hellwig Cc: stable@vger.kernel.org # 3.14+ Signed-off-by: Nicholas Bellinger

target: support XCOPY requests without parameters

2017-01-10T16:41:30Z

SPC4r37 6.4.1 EXTENDED COPY(LID4) states (also applying to LID1 reqs): A parameter list length of zero specifies that the copy manager shall not transfer any data or alter any internal state, and this shall not be considered an error. This behaviour can be tested using the libiscsi ExtendedCopy.ParamHdr test. Signed-off-by: David Disseldorp Reviewed-by: Christoph Hellwig Signed-off-by: Bart Van Assche

target: check for XCOPY parameter truncation

2017-01-10T16:41:27Z

Check for XCOPY header, CSCD descriptor and segment descriptor list truncation, and respond accordingly. SPC4r37 6.4.1 EXTENDED COPY(LID4) states (also applying to LID1 reqs): If the parameter list length causes truncation of the parameter list, then the copy manager shall transfer no data and shall terminate the EXTENDED COPY command with CHECK CONDITION status, with the sense key set to ILLEGAL REQUEST, and the additional sense code set to PARAMETER LIST LENGTH ERROR. This behaviour can be tested using the libiscsi ExtendedCopy.ParamHdr test. Signed-off-by: David Disseldorp Reviewed-by: Christoph Hellwig Signed-off-by: Bart Van Assche

target: use XCOPY segment descriptor CSCD IDs

2017-01-10T16:41:19Z

The XCOPY specification in SPC4r37 states that the XCOPY source and destination device(s) should be derived from the copy source and copy destination (CSCD) descriptor IDs in the XCOPY segment descriptor. The CSCD IDs are generally (for block -> block copies), indexes into the corresponding CSCD descriptor list, e.g. ================================= EXTENDED COPY Header ================================= CSCD Descriptor List - entry 0 + LU ID <--------------<------------------\ - entry 1 | + LU ID <______________<_____________ | ================================= | | Segment Descriptor List | | - segment 0 | | + src CSCD ID = 0 --------->---------+----/ + dest CSCD ID = 1 ___________>______| + len + src lba + dest lba ================================= Currently LIO completely ignores the src and dest CSCD IDs in the Segment Descriptor List, and instead assumes that the first entry in the CSCD list corresponds to the source, and the second to the destination. This commit removes this assumption, by ensuring that the Segment Descriptor List is parsed prior to processing the CSCD Descriptor List. CSCD Descriptor List processing is modified to compare the current list index with the previously obtained src and dest CSCD IDs. Additionally, XCOPY requests where the src and dest CSCD IDs refer to the CSCD Descriptor List entry can now be successfully processed. Fixes: cbf031f ("target: Add support for EXTENDED_COPY copy offload") Link: https://bugzilla.kernel.org/show_bug.cgi?id=191381 Signed-off-by: David Disseldorp Reviewed-by: Christoph Hellwig Signed-off-by: Bart Van Assche

target: check XCOPY segment descriptor CSCD IDs

2017-01-10T16:41:13Z

Ensure that the segment descriptor CSCD descriptor ID values correspond to CSCD descriptor entries located in the XCOPY command parameter list. SPC4r37 6.4.6.1 Table 150 specifies this range as 0000h to 07FFh, where the CSCD descriptor location in the parameter list can be located via: 16 + (id * 32) Signed-off-by: David Disseldorp Reviewed-by: Christoph Hellwig [ bvanassche: inserted "; " in the format string of an error message and also moved a "||" operator from the start of a line to the end of the previous line ] Signed-off-by: Bart Van Assche

target: simplify XCOPY wwn->se_dev lookup helper

2017-01-10T16:41:12Z

target_xcopy_locate_se_dev_e4() is used to locate an se_dev, based on the WWN provided with the XCOPY request. Remove a couple of unneeded arguments, and rely on the caller for the src/dst test. Signed-off-by: David Disseldorp Reviewed-by: Christoph Hellwig Signed-off-by: Bart Van Assche

target: return UNSUPPORTED TARGET/SEGMENT DESC TYPE CODE sense

2017-01-10T16:41:09Z

Use UNSUPPORTED TARGET DESCRIPTOR TYPE CODE and UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE additional sense codes if a descriptor type in an XCOPY request is not supported, as specified in spc4r37 6.4.5 and 6.4.6. Signed-off-by: David Disseldorp Reviewed-by: Christoph Hellwig Signed-off-by: Bart Van Assche