user/sven/linux.git/include/target/iscsi, branch v5.7

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

2020-03-27T01:47:47Z

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

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/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: use ISCSI_IQN_LEN in iscsi_target_stat

2018-10-16T04:38:36Z

Move the ISCSI_IQN_LEN definition up, so that it can be used in more places instead of a hardcoded value. Signed-off-by: David Disseldorp Signed-off-by: Martin K. Petersen

scsi: target: Convert target drivers to use sbitmap

2018-06-20T02:02:25Z

The sbitmap and the percpu_ida perform essentially the same task, allocating tags for commands. The sbitmap outperforms the percpu_ida as documented here: https://lkml.org/lkml/2014/4/22/553 The sbitmap interface is a little harder to use, but being able to remove the percpu_ida code and getting better performance justifies the additional complexity. Signed-off-by: Matthew Wilcox Acked-by: Felipe Balbi # f_tcm Reviewed-by: Jens Axboe Signed-off-by: Martin K. Petersen

Merge tag 'configfs-for-4.15' of git://git.infradead.org/users/hch/configfs

2017-11-14T22:44:04Z

Pull configfs updates from Christoph Hellwig: "A couple of configfs cleanups: - proper use of the bool type (Thomas Meyer) - constification of struct config_item_type (Bhumika Goyal)" * tag 'configfs-for-4.15' of git://git.infradead.org/users/hch/configfs: RDMA/cma: make config_item_type const stm class: make config_item_type const ACPI: configfs: make config_item_type const nvmet: make config_item_type const usb: gadget: configfs: make config_item_type const PCI: endpoint: make config_item_type const iio: make function argument and some structures const usb: gadget: make config_item_type structures const dlm: make config_item_type const netconsole: make config_item_type const nullb: make config_item_type const ocfs2/cluster: make config_item_type const target: make config_item_type const configfs: make ci_type field, some pointers and function arguments const configfs: make config_item_type const configfs: Fix bool initialization/comparison

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

target: make config_item_type const

2017-10-19T14:15:17Z

Make these structures const as they are either passed to the functions having the argument as const or stored as a reference in the "ci_type" const field of a config_item structure. Done using Coccinelle. Signed-off-by: Bhumika Goyal Signed-off-by: Christoph Hellwig

iscsi-target: Fix iscsi_np reset hung task during parallel delete

2017-08-06T21:41:41Z

This patch fixes a bug associated with iscsit_reset_np_thread() that can occur during parallel configfs rmdir of a single iscsi_np used across multiple iscsi-target instances, that would result in hung task(s) similar to below where configfs rmdir process context was blocked indefinately waiting for iscsi_np->np_restart_comp to finish: [ 6726.112076] INFO: task dcp_proxy_node_:15550 blocked for more than 120 seconds. [ 6726.119440] Tainted: G W O 4.1.26-3321 #2 [ 6726.125045] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 6726.132927] dcp_proxy_node_ D ffff8803f202bc88 0 15550 1 0x00000000 [ 6726.140058] ffff8803f202bc88 ffff88085c64d960 ffff88083b3b1ad0 ffff88087fffeb08 [ 6726.147593] ffff8803f202c000 7fffffffffffffff ffff88083f459c28 ffff88083b3b1ad0 [ 6726.155132] ffff88035373c100 ffff8803f202bca8 ffffffff8168ced2 ffff8803f202bcb8 [ 6726.162667] Call Trace: [ 6726.165150] [] schedule+0x32/0x80 [ 6726.170156] [] schedule_timeout+0x214/0x290 [ 6726.176030] [] ? __send_signal+0x52/0x4a0 [ 6726.181728] [] wait_for_completion+0x96/0x100 [ 6726.187774] [] ? wake_up_state+0x10/0x10 [ 6726.193395] [] iscsit_reset_np_thread+0x62/0xe0 [iscsi_target_mod] [ 6726.201278] [] iscsit_tpg_disable_portal_group+0x96/0x190 [iscsi_target_mod] [ 6726.210033] [] lio_target_tpg_store_enable+0x4f/0xc0 [iscsi_target_mod] [ 6726.218351] [] configfs_write_file+0xaa/0x110 [ 6726.224392] [] vfs_write+0xa4/0x1b0 [ 6726.229576] [] SyS_write+0x41/0xb0 [ 6726.234659] [] system_call_fastpath+0x12/0x71 It would happen because each iscsit_reset_np_thread() sets state to ISCSI_NP_THREAD_RESET, sends SIGINT, and then blocks waiting for completion on iscsi_np->np_restart_comp. However, if iscsi_np was active processing a login request and more than a single iscsit_reset_np_thread() caller to the same iscsi_np was blocked on iscsi_np->np_restart_comp, iscsi_np kthread process context in __iscsi_target_login_thread() would flush pending signals and only perform a single completion of np->np_restart_comp before going back to sleep within transport specific iscsit_transport->iscsi_accept_np code. To address this bug, add a iscsi_np->np_reset_count and update __iscsi_target_login_thread() to keep completing np->np_restart_comp until ->np_reset_count has reached zero. Reported-by: Gary Guo Tested-by: Gary Guo Cc: Mike Christie Cc: Hannes Reinecke Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger