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Tyrel Datwyler 72ea7fe0db scsi: ibmvfc: Allocate/free queue resource only during probe/remove
Currently, the sub-queues and event pool resources are allocated/freed for
every CRQ connection event such as reset and LPM. This exposes the driver
to a couple issues. First the inefficiency of freeing and reallocating
memory that can simply be resued after being sanitized. Further, a system
under memory pressue runs the risk of allocation failures that could result
in a crippled driver. Finally, there is a race window where command
submission/compeletion can try to pull/return elements from/to an event
pool that is being deleted or already has been deleted due to the lack of
host state around freeing/allocating resources. The following is an example
of list corruption following a live partition migration (LPM):

Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: vfat fat isofs cdrom ext4 mbcache jbd2 nft_counter nft_compat nf_tables nfnetlink rpadlpar_io rpaphp xsk_diag nfsv3 nfs_acl nfs lockd grace fscache netfs rfkill bonding tls sunrpc pseries_rng drm drm_panel_orientation_quirks xfs libcrc32c dm_service_time sd_mod t10_pi sg ibmvfc scsi_transport_fc ibmveth vmx_crypto dm_multipath dm_mirror dm_region_hash dm_log dm_mod ipmi_devintf ipmi_msghandler fuse
CPU: 0 PID: 2108 Comm: ibmvfc_0 Kdump: loaded Not tainted 5.14.0-70.9.1.el9_0.ppc64le #1
NIP: c0000000007c4bb0 LR: c0000000007c4bac CTR: 00000000005b9a10
REGS: c00000025c10b760 TRAP: 0700  Not tainted (5.14.0-70.9.1.el9_0.ppc64le)
MSR: 800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 2800028f XER: 0000000f
CFAR: c0000000001f55bc IRQMASK: 0
        GPR00: c0000000007c4bac c00000025c10ba00 c000000002a47c00 000000000000004e
        GPR04: c0000031e3006f88 c0000031e308bd00 c00000025c10b768 0000000000000027
        GPR08: 0000000000000000 c0000031e3009dc0 00000031e0eb0000 0000000000000000
        GPR12: c0000031e2ffffa8 c000000002dd0000 c000000000187108 c00000020fcee2c0
        GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
        GPR20: 0000000000000000 0000000000000000 0000000000000000 c008000002f81300
        GPR24: 5deadbeef0000100 5deadbeef0000122 c000000263ba6910 c00000024cc88000
        GPR28: 000000000000003c c0000002430a0000 c0000002430ac300 000000000000c300
NIP [c0000000007c4bb0] __list_del_entry_valid+0x90/0x100
LR [c0000000007c4bac] __list_del_entry_valid+0x8c/0x100
Call Trace:
[c00000025c10ba00] [c0000000007c4bac] __list_del_entry_valid+0x8c/0x100 (unreliable)
[c00000025c10ba60] [c008000002f42284] ibmvfc_free_queue+0xec/0x210 [ibmvfc]
[c00000025c10bb10] [c008000002f4246c] ibmvfc_deregister_scsi_channel+0xc4/0x160 [ibmvfc]
[c00000025c10bba0] [c008000002f42580] ibmvfc_release_sub_crqs+0x78/0x130 [ibmvfc]
[c00000025c10bc20] [c008000002f4f6cc] ibmvfc_do_work+0x5c4/0xc70 [ibmvfc]
[c00000025c10bce0] [c008000002f4fdec] ibmvfc_work+0x74/0x1e8 [ibmvfc]
[c00000025c10bda0] [c0000000001872b8] kthread+0x1b8/0x1c0
[c00000025c10be10] [c00000000000cd64] ret_from_kernel_thread+0x5c/0x64
Instruction dump:
40820034 38600001 38210060 4e800020 7c0802a6 7c641b78 3c62fe7a 7d254b78
3863b590 f8010070 4ba309cd 60000000 <0fe00000> 7c0802a6 3c62fe7a 3863b640
---[ end trace 11a2b65a92f8b66c ]---
ibmvfc 30000003: Send warning. Receive queue closed, will retry.

Add registration/deregistration helpers that are called instead during
connection resets to sanitize and reconfigure the queues.

Link: https://lore.kernel.org/r/20220616191126.1281259-3-tyreld@linux.ibm.com
Fixes: 3034ebe263 ("scsi: ibmvfc: Add alloc/dealloc routines for SCSI Sub-CRQ Channels")
Cc: stable@vger.kernel.org
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-06-16 21:40:10 -04:00
arch Hot fixes for 5.19-rc1. 2022-06-05 17:05:38 -07:00
block for-5.19/drivers-2022-06-02 2022-06-03 10:25:56 -07:00
certs Kbuild updates for v5.19 2022-05-26 12:09:50 -07:00
crypto This update includes the following changes: 2022-05-27 18:06:49 -07:00
Documentation A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
drivers scsi: ibmvfc: Allocate/free queue resource only during probe/remove 2022-06-16 21:40:10 -04:00
fs fix for breakage in #work.fd this window 2022-06-05 17:14:03 -07:00
include A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
init This set of changes updates init and user mode helper tasks to be 2022-06-03 16:03:05 -07:00
ipc These changes update the ipc sysctls so that they are fundamentally 2022-06-03 15:54:57 -07:00
kernel A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
lib Bitmap patches for 5.19-rc1 2022-06-04 14:04:27 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm Hot fixes for 5.19-rc1. 2022-06-05 17:05:38 -07:00
net bluetooth: don't use bitmaps for random flag accesses 2022-06-05 16:28:41 -07:00
samples drm for 5.19-rc1 2022-05-25 16:18:27 -07:00
scripts A set of objtool fixes: 2022-06-05 09:45:27 -07:00
security Cleanups (and one fix) around struct mount handling. 2022-06-04 19:00:05 -07:00
sound USB / Thunderbolt changes for 5.19-rc1 2022-06-03 11:17:49 -07:00
tools A single featurelet for delay accounting. Delayed a bit 2022-06-05 16:58:27 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt VFIO updates for v5.19-rc1 2022-06-01 13:49:15 -07:00
.clang-format clang-format: Fix space after for_each macros 2022-05-20 19:27:16 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Hot fixes for 5.19-rc1. 2022-06-05 17:05:38 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Hot fixes for 5.19-rc1. 2022-06-05 17:05:38 -07:00
Makefile Linux 5.19-rc1 2022-06-05 17:18:54 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.