Commit Graph

223 Commits

Author SHA1 Message Date
Eric Dumazet
56440d7ec2 genetlink: hold RCU in genlmsg_mcast()
While running net selftests with CONFIG_PROVE_RCU_LIST=y I saw
one lockdep splat [1].

genlmsg_mcast() uses for_each_net_rcu(), and must therefore hold RCU.

Instead of letting all callers guard genlmsg_multicast_allns()
with a rcu_read_lock()/rcu_read_unlock() pair, do it in genlmsg_mcast().

This also means the @flags parameter is useless, we need to always use
GFP_ATOMIC.

[1]
[10882.424136] =============================
[10882.424166] WARNING: suspicious RCU usage
[10882.424309] 6.12.0-rc2-virtme #1156 Not tainted
[10882.424400] -----------------------------
[10882.424423] net/netlink/genetlink.c:1940 RCU-list traversed in non-reader section!!
[10882.424469]
other info that might help us debug this:

[10882.424500]
rcu_scheduler_active = 2, debug_locks = 1
[10882.424744] 2 locks held by ip/15677:
[10882.424791] #0: ffffffffb6b491b0 (cb_lock){++++}-{3:3}, at: genl_rcv (net/netlink/genetlink.c:1219)
[10882.426334] #1: ffffffffb6b49248 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg (net/netlink/genetlink.c:61 net/netlink/genetlink.c:57 net/netlink/genetlink.c:1209)
[10882.426465]
stack backtrace:
[10882.426805] CPU: 14 UID: 0 PID: 15677 Comm: ip Not tainted 6.12.0-rc2-virtme #1156
[10882.426919] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[10882.427046] Call Trace:
[10882.427131]  <TASK>
[10882.427244] dump_stack_lvl (lib/dump_stack.c:123)
[10882.427335] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822)
[10882.427387] genlmsg_multicast_allns (net/netlink/genetlink.c:1940 (discriminator 7) net/netlink/genetlink.c:1977 (discriminator 7))
[10882.427436] l2tp_tunnel_notify.constprop.0 (net/l2tp/l2tp_netlink.c:119) l2tp_netlink
[10882.427683] l2tp_nl_cmd_tunnel_create (net/l2tp/l2tp_netlink.c:253) l2tp_netlink
[10882.427748] genl_family_rcv_msg_doit (net/netlink/genetlink.c:1115)
[10882.427834] genl_rcv_msg (net/netlink/genetlink.c:1195 net/netlink/genetlink.c:1210)
[10882.427877] ? __pfx_l2tp_nl_cmd_tunnel_create (net/l2tp/l2tp_netlink.c:186) l2tp_netlink
[10882.427927] ? __pfx_genl_rcv_msg (net/netlink/genetlink.c:1201)
[10882.427959] netlink_rcv_skb (net/netlink/af_netlink.c:2551)
[10882.428069] genl_rcv (net/netlink/genetlink.c:1220)
[10882.428095] netlink_unicast (net/netlink/af_netlink.c:1332 net/netlink/af_netlink.c:1357)
[10882.428140] netlink_sendmsg (net/netlink/af_netlink.c:1901)
[10882.428210] ____sys_sendmsg (net/socket.c:729 (discriminator 1) net/socket.c:744 (discriminator 1) net/socket.c:2607 (discriminator 1))

Fixes: 33f72e6f0c ("l2tp : multicast notification to the registered listeners")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Cc: Tom Parkin <tparkin@katalix.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Link: https://patch.msgid.link/20241011171217.3166614-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-15 17:52:58 -07:00
Kees Cook
caf22c969e scsi: target: tcmu: Annotate struct tcmu_tmr with __counted_by
Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct tcmu_tmr.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Bodo Stroesser <bostroesser@gmail.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Cc: target-devel@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230922175300.work.148-kees@kernel.org
Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-09-27 11:28:48 -04:00
Azeem Shaikh
4b2e28758d scsi: target: tcmu: Replace strlcpy() with strscpy()
strlcpy() reads the entire source buffer first.  This read may exceed the
destination size limit.  This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated [1].  In an effort
to remove strlcpy() completely [2], replace strlcpy() here with strscpy().

No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Link: https://lore.kernel.org/r/20230621030033.3800351-3-azeemshaikh38@gmail.com
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-06-21 21:13:00 -04:00
Suren Baghdasaryan
1c71222e5f mm: replace vma->vm_flags direct modifications with modifier calls
Replace direct modifications to vma->vm_flags with calls to modifier
functions to be able to track flag changes and to keep vma locking
correctness.

[akpm@linux-foundation.org: fix drivers/misc/open-dice.c, per Hyeonggon Yoo]
Link: https://lkml.kernel.org/r/20230126193752.297968-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Oskolkov <posk@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:39 -08:00
Jakub Kicinski
9c5d03d362 genetlink: start to validate reserved header bytes
We had historically not checked that genlmsghdr.reserved
is 0 on input which prevents us from using those precious
bytes in the future.

One use case would be to extend the cmd field, which is
currently just 8 bits wide and 256 is not a lot of commands
for some core families.

To make sure that new families do the right thing by default
put the onus of opting out of validation on existing families.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com> (NetLabel)
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-29 12:47:15 +01:00
Bodo Stroesser
325d5c5fb2 scsi: target: tcmu: Avoid holding XArray lock when calling lock_page
In tcmu_blocks_release(), lock_page() is called to prevent a race causing
possible data corruption. Since lock_page() might sleep, calling it while
holding XArray lock is a bug.

To fix this, replace the xas_for_each() call with xa_for_each_range().
Since the latter does its own handling of XArray locking, the xas_lock()
and xas_unlock() calls around the original loop are no longer necessary.

The switch to xa_for_each_range() slows down the loop slightly. This is
acceptable since tcmu_blocks_release() is not relevant for performance.

Link: https://lore.kernel.org/r/20220517192913.21405-1-bostroesser@gmail.com
Fixes: bb9b9eb0ae ("scsi: target: tcmu: Fix possible data corruption")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-05-19 20:16:27 -04:00
Xiaoguang Wang
bb9b9eb0ae scsi: target: tcmu: Fix possible data corruption
When tcmu_vma_fault() gets a page successfully, before the current context
completes page fault procedure, find_free_blocks() may run and call
unmap_mapping_range() to unmap the page. Assume that when
find_free_blocks() initially completes and the previous page fault
procedure starts to run again and completes, then one truncated page has
been mapped to userspace. But note that tcmu_vma_fault() has gotten a
refcount for the page so any other subsystem won't be able to use the page
unless the userspace address is unmapped later.

If another command subsequently runs and needs to extend dbi_thresh it may
reuse the corresponding slot for the previous page in data_bitmap. Then
though we'll allocate new page for this slot in data_area, no page fault
will happen because we have a valid map and the real request's data will be
lost.

Filesystem implementations will also run into this issue but they usually
lock the page when vm_operations_struct->fault gets a page and unlock the
page after finish_fault() completes. For truncate filesystems lock pages in
truncate_inode_pages() to protect against racing wrt. page faults.

To fix this possible data corruption scenario we can apply a method similar
to the filesystems.  For pages that are to be freed, tcmu_blocks_release()
locks and unlocks. Make tcmu_vma_fault() also lock found page under
cmdr_lock. At the same time, since tcmu_vma_fault() gets an extra page
refcount, tcmu_blocks_release() won't free pages if pages are in page fault
procedure, which means it is safe to call tcmu_blocks_release() before
unmap_mapping_range().

With these changes tcmu_blocks_release() will wait for all page faults to
be completed before calling unmap_mapping_range(). And later, if
unmap_mapping_range() is called, it will ensure stale mappings are removed.

Link: https://lore.kernel.org/r/20220421023735.9018-1-xiaoguang.wang@linux.alibaba.com
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-05-02 16:59:11 -04:00
Xiaoguang Wang
a6968f7a36 scsi: target: tcmu: Fix possible page UAF
tcmu_try_get_data_page() looks up pages under cmdr_lock, but it does not
take refcount properly and just returns page pointer. When
tcmu_try_get_data_page() returns, the returned page may have been freed by
tcmu_blocks_release().

We need to get_page() under cmdr_lock to avoid concurrent
tcmu_blocks_release().

Link: https://lore.kernel.org/r/20220311132206.24515-1-xiaoguang.wang@linux.alibaba.com
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-03-29 23:07:56 -04:00
Guixin Liu
c7ede4f044 scsi: target: tcmu: Make cmd_ring_size changeable via configfs
Make cmd_ring_size changeable similar to the way it is done for
max_data_area_mb. The reason is that our tcmu client will create thousands
of tcmu instances, and this will consume lots of mem with default 8Mb cmd
ring size for every backstore.

One can change the value by typing:

    echo "cmd_ring_size_mb=N" > control

The "N" is a integer between 1 to 8, if set 1, the cmd ring can hold about
6k cmds(tcmu_cmd_entry about 176 byte) at least.

The value is printed when doing:

    cat info

In addition, a new readonly attribute 'cmd_ring_size_mb' returns the value
in read.

Link: https://lore.kernel.org/r/1644978109-14885-1-git-send-email-kanie@linux.alibaba.com
Reviewed-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-02-22 21:11:07 -05:00
Bodo Stroesser
1d2ac7b69d scsi: target: tcmu: Allocate zeroed pages for data area
Tcmu populates the data area (used for communication with userspace) with
pages that are allocated by calling alloc_page(GFP_NOIO).  Therefore
previous content of the allocated pages is exposed to user space. Avoid
this by adding __GFP_ZERO flag.

Zeroing the pages does (nearly) not affect tcmu throughput, because
allocated pages are re-used for the data transfers of later SCSI cmds.

Link: https://lore.kernel.org/r/20211013171606.25197-1-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-10-18 22:38:35 -04:00
Gustavo A. R. Silva
c20bda3419 scsi: target: tcmu: Use struct_size() helper in kmalloc()
Make use of the struct_size() helper instead of an open-coded version, in
order to avoid any potential type mistakes or integer overflows that, in
the worst scenario, could lead to heap overflows.

Link: https://github.com/KSPP/linux/issues/160
Link: https://lore.kernel.org/r/20210927224344.GA190701@embeddedor
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-10-04 23:29:38 -04:00
Bodo Stroesser
018c14911d scsi: target: tcmu: Add new feature KEEP_BUF
When running command pipelining for WRITE direction commands (e.g. tape
device write), userspace sends cmd completion to cmd ring before processing
write data. In that case userspace has to copy data before sending
completion, because cmd completion also implicitly releases the data buffer
in data area.

The new feature KEEP_BUF allows userspace to optionally keep the buffer
after completion by setting new bit TCMU_UFLAG_KEEP_BUF in
tcmu_cmd_entry_hdr->uflags. In that case buffer has to be released
explicitly by writing the cmd_id to new action item free_kept_buf.

All kept buffers are released during reset_ring and if userspace closes uio
device (tcmu_release).

Link: https://lore.kernel.org/r/20210713175021.20103-1-bostroesser@gmail.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-08-03 07:27:42 -04:00
Linus Torvalds
bd31b9efbf SCSI misc on 20210702
This series consists of the usual driver updates (ufs, ibmvfc,
 megaraid_sas, lpfc, elx, mpi3mr, qedi, iscsi, storvsc, mpt3sas) with
 elx and mpi3mr being new drivers.  The major core change is a rework
 to drop the status byte handling macros and the old bit shifted
 definitions and the rest of the updates are minor fixes.
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This series consists of the usual driver updates (ufs, ibmvfc,
  megaraid_sas, lpfc, elx, mpi3mr, qedi, iscsi, storvsc, mpt3sas) with
  elx and mpi3mr being new drivers.

  The major core change is a rework to drop the status byte handling
  macros and the old bit shifted definitions and the rest of the updates
  are minor fixes"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (287 commits)
  scsi: aha1740: Avoid over-read of sense buffer
  scsi: arcmsr: Avoid over-read of sense buffer
  scsi: ips: Avoid over-read of sense buffer
  scsi: ufs: ufs-mediatek: Add missing of_node_put() in ufs_mtk_probe()
  scsi: elx: libefc: Fix IRQ restore in efc_domain_dispatch_frame()
  scsi: elx: libefc: Fix less than zero comparison of a unsigned int
  scsi: elx: efct: Fix pointer error checking in debugfs init
  scsi: elx: efct: Fix is_originator return code type
  scsi: elx: efct: Fix link error for _bad_cmpxchg
  scsi: elx: efct: Eliminate unnecessary boolean check in efct_hw_command_cancel()
  scsi: elx: efct: Do not use id uninitialized in efct_lio_setup_session()
  scsi: elx: efct: Fix error handling in efct_hw_init()
  scsi: elx: efct: Remove redundant initialization of variable lun
  scsi: elx: efct: Fix spelling mistake "Unexected" -> "Unexpected"
  scsi: lpfc: Fix build error in lpfc_scsi.c
  scsi: target: iscsi: Remove redundant continue statement
  scsi: qla4xxx: Remove redundant continue statement
  scsi: ppa: Switch to use module_parport_driver()
  scsi: imm: Switch to use module_parport_driver()
  scsi: mpt3sas: Fix error return value in _scsih_expander_add()
  ...
2021-07-02 15:14:36 -07:00
kernel test robot
824731258b scsi: target: tcmu: Fix boolreturn.cocci warnings
drivers/target/target_core_user.c:1424:9-10: WARNING: return of 0/1 in function 'tcmu_handle_completions' with return type bool

 Return statements in functions returning bool should use
 true/false instead of 1/0.

Generated by: scripts/coccinelle/misc/boolreturn.cocci

Link: https://lore.kernel.org/r/20210515230358.GA97544@60d1edce16e0
Fixes: 9814b55cde ("scsi: target: tcmu: Return from tcmu_handle_completions() if cmd_id not found")
CC: Bodo Stroesser <bostroesser@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-21 17:14:21 -04:00
Bodo Stroesser
b4150b6881 scsi: target: tcmu: Fix xarray RCU warning
Commit f5ce815f34 ("scsi: target: tcmu: Support DATA_BLOCK_SIZE = N *
PAGE_SIZE") introduced xas_next() calls to iterate xarray elements.  These
calls triggered the WARNING "suspicious RCU usage" at tcmu device set up
[1]. In the call stack of xas_next(), xas_load() was called.  According to
its comment, this function requires "the xa_lock or the RCU lock".

To avoid the warning:

 - Guard the small loop calling xas_next() in tcmu_get_empty_block with RCU
   lock.

 - In the large loop in tcmu_copy_data using RCU lock would possibly
   disable preemtion for a long time (copy multi MBs). Therefore replace
   XA_STATE, xas_set and xas_next with a single xa_load.

[1]

[ 1899.867091] =============================
[ 1899.871199] WARNING: suspicious RCU usage
[ 1899.875310] 5.13.0-rc1+ #41 Not tainted
[ 1899.879222] -----------------------------
[ 1899.883299] include/linux/xarray.h:1182 suspicious rcu_dereference_check() usage!
[ 1899.890940] other info that might help us debug this:
[ 1899.899082] rcu_scheduler_active = 2, debug_locks = 1
[ 1899.905719] 3 locks held by kworker/0:1/1368:
[ 1899.910161]  #0: ffffa1f8c8b98738 ((wq_completion)target_submission){+.+.}-{0:0}, at: process_one_work+0x1ee/0x580
[ 1899.920732]  #1: ffffbd7040cd7e78 ((work_completion)(&q->sq.work)){+.+.}-{0:0}, at: process_one_work+0x1ee/0x580
[ 1899.931146]  #2: ffffa1f8d1c99768 (&udev->cmdr_lock){+.+.}-{3:3}, at: tcmu_queue_cmd+0xea/0x160 [target_core_user]
[ 1899.941678] stack backtrace:
[ 1899.946093] CPU: 0 PID: 1368 Comm: kworker/0:1 Not tainted 5.13.0-rc1+ #41
[ 1899.953070] Hardware name: System manufacturer System Product Name/PRIME Z270-A, BIOS 1302 03/15/2018
[ 1899.962459] Workqueue: target_submission target_queued_submit_work [target_core_mod]
[ 1899.970337] Call Trace:
[ 1899.972839]  dump_stack+0x6d/0x89
[ 1899.976222]  xas_descend+0x10e/0x120
[ 1899.979875]  xas_load+0x39/0x50
[ 1899.983077]  tcmu_get_empty_blocks+0x115/0x1c0 [target_core_user]
[ 1899.989318]  queue_cmd_ring+0x1da/0x630 [target_core_user]
[ 1899.994897]  ? rcu_read_lock_sched_held+0x3f/0x70
[ 1899.999695]  ? trace_kmalloc+0xa6/0xd0
[ 1900.003501]  ? __kmalloc+0x205/0x380
[ 1900.007167]  tcmu_queue_cmd+0x12f/0x160 [target_core_user]
[ 1900.012746]  __target_execute_cmd+0x23/0xa0 [target_core_mod]
[ 1900.018589]  transport_generic_new_cmd+0x1f3/0x370 [target_core_mod]
[ 1900.025046]  transport_handle_cdb_direct+0x34/0x50 [target_core_mod]
[ 1900.031517]  target_queued_submit_work+0x43/0xe0 [target_core_mod]
[ 1900.037837]  process_one_work+0x268/0x580
[ 1900.041952]  ? process_one_work+0x580/0x580
[ 1900.046195]  worker_thread+0x55/0x3b0
[ 1900.049921]  ? process_one_work+0x580/0x580
[ 1900.054192]  kthread+0x143/0x160
[ 1900.057499]  ? kthread_create_worker_on_cpu+0x40/0x40
[ 1900.062661]  ret_from_fork+0x1f/0x30

Link: https://lore.kernel.org/r/20210519135440.26773-1-bostroesser@gmail.com
Fixes: f5ce815f34 ("scsi: target: tcmu: Support DATA_BLOCK_SIZE = N * PAGE_SIZE")
Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-21 16:15:48 -04:00
Bodo Stroesser
3ac0fcb4b1 scsi: target: tcmu: Rename TCM_DEV_BIT_PLUGGED to TCMU_DEV_BIT_PLUGGED
The bit definition TCM_DEV_BIT_PLUGGED should correctly be named
TCMU_DEV_BIT_PLUGGED, since all other bits in the same bitfield have prefix
TCMU_.

Link: https://lore.kernel.org/r/20210512140654.31249-1-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-14 22:58:27 -04:00
Bodo Stroesser
9814b55cde scsi: target: tcmu: Return from tcmu_handle_completions() if cmd_id not found
If tcmu_handle_completions() finds an invalid cmd_id while looping over cmd
responses from userspace it sets TCMU_DEV_BIT_BROKEN and breaks the
loop. This means that it does further handling for the tcmu device.

Skip that handling by replacing 'break' with 'return'.

Additionally change tcmu_handle_completions() from unsigned int to bool,
since the value used in return already is bool.

Link: https://lore.kernel.org/r/20210423150123.24468-1-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-28 22:55:00 -04:00
Bodo Stroesser
08976cb548 scsi: target: tcmu: Make data_pages_per_blk changeable via configfs
Make data_pages_per_blk changeable similar to the way it is done for
max_data_area_mb. One can change the value by typing:

  echo "data_pages_per_blk=N" >control

The value is printed when doing:

  cat info

In addition, a new readonly attribute 'data_pages_per_blk' returns the
value on read.

Link: https://lore.kernel.org/r/20210324195758.2021-7-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-12 22:40:56 -04:00
Bodo Stroesser
e719afdcf6 scsi: target: tcmu: Replace block size definitions with new udev members
Replace DATA_PAGES_PER_BLK and DATA_BLOCK_SIZE with new struct elements
tcmu_dev->data_pages_per_blk and tcmu_dev->data_blk_size.  These new
variables are still loaded with constant definition DATA_PAGES_PER_BLK_DEF
(= 1) and DATA_PAGES_PER_BLK_DEF * PAGE_SIZE.

There is no way yet to set the values via configfs.

Link: https://lore.kernel.org/r/20210324195758.2021-6-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-12 22:40:56 -04:00
Bodo Stroesser
3722e36c4e scsi: target: tcmu: Remove function tcmu_get_block_page()
There is only one caller of tcmu_get_block_page left. Since it is a
one-liner, we can remove the function.

Link: https://lore.kernel.org/r/20210324195758.2021-5-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-12 22:40:55 -04:00
Bodo Stroesser
f5ce815f34 scsi: target: tcmu: Support DATA_BLOCK_SIZE = N * PAGE_SIZE
Change tcmu to support DATA_BLOCK_SIZE being a multiple of PAGE_SIZE. There
are two reasons why one would like to have a bigger DATA_BLOCK_SIZE:

 1) If userspace - e.g. due to data compression, encryption or
    deduplication - needs to have receive or transmit data in a consecutive
    buffer, we can define DATA_BLOCK_SIZE to the maximum size of a SCSI
    READ/WRITE to enforce that userspace sees just one consecutive
    buffer. That way we can avoid the need for doing data copy in
    userspace.

 2) Using a bigger data block size can speed up command processing in
    tcmu. The number of free data blocks to look up in bitmap is reduced
    substantially. The lookup for data pages in radix_tree can be done more
    efficiently if there are multiple pages in a data block. The maximum
    number of IOVs to set up is lower so cmd entries in the ring become
    smaller.

Link: https://lore.kernel.org/r/20210324195758.2021-4-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-12 22:40:55 -04:00
Bodo Stroesser
8b084d9dfb scsi: target: tcmu: Prepare for PAGE_SIZE != DATA_BLOCK_SIZE
Rename some variables and definitions as a first preparation for
DATA_BLOCK_SIZE != PAGE_SIZE and add the new DATA_PAGES_PER_BLK definition
containing the number of pages per data block.

Rename tcmu_try_get_block_page() to tcmu_try_get_data_page(). Keep name
tcmu_get_block_page() since it will go away in a following commit when
there is only one caller left.  Subsequent commits will then add full
support for DATA_PAGES_PER_BLK != 1, which also means DATA_BLOCK_SIZE =
DATA_PAGES_PER_BLK * PAGE_SIZE

Link: https://lore.kernel.org/r/20210324195758.2021-3-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-12 22:40:55 -04:00
Bodo Stroesser
ecddbb7e94 scsi: target: tcmu: Adjust names of variables and definitions
Some definitions and members of struct tcmu_dev had misleading
names. Examples:

 - ring_size was used for the size of mailbox + cmd ring + data area

 - CMDR_SIZE was used for size of mailbox + cmd ring

I added the new definition MB_CMDR_SIZE (mailbox + command ring), changed
CMDR_SIZE to hold the size of the command ring only and replaced in struct
tcmu_dev the member ring_size with mmap_pages, because the member is now
used in tcmu_mmap() only, where we need page count, not size.

I also added the new struct tcmu_dev member 'cmdr' which is used to replace
some occurences of '(void *)mb + CMDR_OFF' with 'udev->cmdr' for better
readability.

Link: https://lore.kernel.org/r/20210324195758.2021-2-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-12 22:40:55 -04:00
Bodo Stroesser
471ee95ccc scsi: target: tcmu: Adjust parameter in call to tcmu_blocks_release()
In commit f7c89771d0 ("scsi: target: tcmu: Replace radix_tree with
XArray") the meaning of last parameter of tcmu_blocks_release() was
changed.  So in the callers we should subtract 1 from the previous
parameter.

Unfortunately that change got lost at one of the two places where
tcmu_blocks_release() is called. That does not lead to any problems, but we
should adjust it anyway.

Link: https://lore.kernel.org/r/20210310184458.10741-1-bostroesser@gmail.com
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-03-15 23:18:37 -04:00
Bodo Stroesser
1080782f13 scsi: target: tcmu: Use GFP_NOIO while handling cmds or holding cmdr_lock
Especially when using tcmu with tcm_loop, memory allocations with
GFP_KERNEL for a LUN can cause write back to the same LUN.

So we have to use GFP_NOIO when allocation is done while handling commands
or while holding cmdr_lock.

Link: https://lore.kernel.org/r/20210305190009.32242-1-bostroesser@gmail.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-03-09 23:47:17 -05:00
Bodo Stroesser
f7c89771d0 scsi: target: tcmu: Replace radix_tree with XArray
An attempt from Matthew Wilcox to replace radix-tree usage by XArray in
tcmu more than 1 year ago unfortunately got lost.

I rebased that work on latest tcmu and tested it.

Link: https://lore.kernel.org/r/20210224185335.13844-3-bostroesser@gmail.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-03-09 23:47:17 -05:00
Bodo Stroesser
d3cbb743c3 scsi: target: tcmu: Replace IDR by XArray
An attempt from Matthew Wilcox to replace IDR usage by XArray in tcmu more
than 1 year ago unfortunately got lost.

I rebased that work on latest tcmu and tested it.

Link: https://lore.kernel.org/r/20210224185335.13844-2-bostroesser@gmail.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-03-09 23:47:17 -05:00
Mike Christie
6888da8179 scsi: target: tcmu: Add backend plug/unplug callouts
This patch adds plug/unplug callouts for tcmu, so we can avoid the number
of times we switch to userspace. Using this driver with tcm_loop is a
common config, and dependng on the nr_hw_queues (nr_hw_queues=1 performs
much better) and fio jobs (lower num jobs around 4) this patch can increase
IOPS by only around 5-10% because we hit other issues like the big per tcmu
device mutex.

Link: https://lore.kernel.org/r/20210227170006.5077-24-michael.christie@oracle.com
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-03-04 17:37:02 -05:00
Bodo Stroesser
8f33bb2400 scsi: target: tcmu: Fix memory leak caused by wrong uio usage
When user deletes a tcmu device via configFS, tcmu calls
uio_unregister_device(). During that call uio resets its pointer to struct
uio_info provided by tcmu. That means, after uio_unregister_device() uio
will no longer execute any of the callbacks tcmu had set in uio_info.

Especially, if userspace daemon still holds the corresponding uio device
open or mmap'ed while tcmu calls uio_unregister_device(), uio will not call
tcmu_release() when userspace finally closes and munmaps the uio device.

Since tcmu does refcounting for the tcmu device in tcmu_open() and
tcmu_release(), in the decribed case refcount does not drop to 0 and tcmu
does not free tcmu device's resources.  In extreme cases this can cause
memory leaking of up to 1 GB for a single tcmu device.

After uio_unregister_device(), uio will reject every open, read, write,
mmap from userspace with -EOI. But userspace daemon can still access the
mmap'ed command ring and data area. Therefore tcmu should wait until
userspace munmaps the uio device before it frees the resources, as we don't
want to cause SIGSEGV or SIGBUS to user space.

That said, current refcounting during tcmu_open and tcmu_release does not
work correctly, and refcounting better should be done in the open and close
callouts of the vm_operations_struct, which tcmu assigns to each mmap of
the uio device (because it wants its own page fault handler).

This patch fixes the memory leak by removing refcounting from tcmu_open and
tcmu_close, and instead adding new tcmu_vma_open() and tcmu_vma_close()
handlers that only do refcounting.

Link: https://lore.kernel.org/r/20210218175039.7829-3-bostroesser@gmail.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-02-22 22:35:21 -05:00
Bodo Stroesser
43bf922cdd scsi: target: tcmu: Move some functions without code change
This patch just moves one block of code containing some functions inside
target_core_user.c to avoid adding prototypes in next patch.

Link: https://lore.kernel.org/r/20210218175039.7829-2-bostroesser@gmail.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-02-22 22:35:21 -05:00
Shin'ichiro Kawasaki
780e138468 scsi: target: tcmu: Fix use-after-free of se_cmd->priv
Commit a35129024e ("scsi: target: tcmu: Use priv pointer in se_cmd")
modified tcmu_free_cmd() to set NULL to priv pointer in se_cmd. However,
se_cmd can be already freed by work queue triggered in
target_complete_cmd(). This caused BUG KASAN use-after-free [1].

To fix the bug, do not touch priv pointer in tcmu_free_cmd(). Instead, set
NULL to priv pointer before target_complete_cmd() calls. Also, to avoid
unnecessary priv pointer change in tcmu_queue_cmd(), modify priv pointer in
the function only when tcmu_free_cmd() is not called.

[1]
BUG: KASAN: use-after-free in tcmu_handle_completions+0x1172/0x1770 [target_core_user]
Write of size 8 at addr ffff88814cf79a40 by task cmdproc-uio0/14842

CPU: 2 PID: 14842 Comm: cmdproc-uio0 Not tainted 5.11.0-rc2 #1
Hardware name: Supermicro Super Server/X10SRL-F, BIOS 3.2 11/22/2019
Call Trace:
 dump_stack+0x9a/0xcc
 ? tcmu_handle_completions+0x1172/0x1770 [target_core_user]
 print_address_description.constprop.0+0x18/0x130
 ? tcmu_handle_completions+0x1172/0x1770 [target_core_user]
 ? tcmu_handle_completions+0x1172/0x1770 [target_core_user]
 kasan_report.cold+0x7f/0x10e
 ? tcmu_handle_completions+0x1172/0x1770 [target_core_user]
 tcmu_handle_completions+0x1172/0x1770 [target_core_user]
 ? queue_tmr_ring+0x5d0/0x5d0 [target_core_user]
 tcmu_irqcontrol+0x28/0x60 [target_core_user]
 uio_write+0x155/0x230
 ? uio_vma_fault+0x460/0x460
 ? security_file_permission+0x4f/0x440
 vfs_write+0x1ce/0x860
 ksys_write+0xe9/0x1b0
 ? __ia32_sys_read+0xb0/0xb0
 ? syscall_enter_from_user_mode+0x27/0x70
 ? trace_hardirqs_on+0x1c/0x110
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fcf8b61905f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 b9 fc ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 0c fd ff ff 48
RSP: 002b:00007fcf7b3e6c30 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcf8b61905f
RDX: 0000000000000004 RSI: 00007fcf7b3e6c78 RDI: 000000000000000c
RBP: 00007fcf7b3e6c80 R08: 0000000000000000 R09: 00007fcf7b3e6aa8
R10: 000000000b01c000 R11: 0000000000000293 R12: 00007ffe0c32a52e
R13: 00007ffe0c32a52f R14: 0000000000000000 R15: 00007fcf7b3e7640

Allocated by task 383:
 kasan_save_stack+0x1b/0x40
 ____kasan_kmalloc.constprop.0+0x84/0xa0
 kmem_cache_alloc+0x142/0x330
 tcm_loop_queuecommand+0x2a/0x4e0 [tcm_loop]
 scsi_queue_rq+0x12ec/0x2d20
 blk_mq_dispatch_rq_list+0x30a/0x1db0
 __blk_mq_do_dispatch_sched+0x326/0x830
 __blk_mq_sched_dispatch_requests+0x2c8/0x3f0
 blk_mq_sched_dispatch_requests+0xca/0x120
 __blk_mq_run_hw_queue+0x93/0xe0
 process_one_work+0x7b6/0x1290
 worker_thread+0x590/0xf80
 kthread+0x362/0x430
 ret_from_fork+0x22/0x30

Freed by task 11655:
 kasan_save_stack+0x1b/0x40
 kasan_set_track+0x1c/0x30
 kasan_set_free_info+0x20/0x30
 ____kasan_slab_free+0xec/0x120
 slab_free_freelist_hook+0x53/0x160
 kmem_cache_free+0xf4/0x5c0
 target_release_cmd_kref+0x3ea/0x9e0 [target_core_mod]
 transport_generic_free_cmd+0x28b/0x2f0 [target_core_mod]
 target_complete_ok_work+0x250/0xac0 [target_core_mod]
 process_one_work+0x7b6/0x1290
 worker_thread+0x590/0xf80
 kthread+0x362/0x430
 ret_from_fork+0x22/0x30

Last potentially related work creation:
 kasan_save_stack+0x1b/0x40
 kasan_record_aux_stack+0xa3/0xb0
 insert_work+0x48/0x2e0
 __queue_work+0x4e8/0xdf0
 queue_work_on+0x78/0x80
 tcmu_handle_completions+0xad0/0x1770 [target_core_user]
 tcmu_irqcontrol+0x28/0x60 [target_core_user]
 uio_write+0x155/0x230
 vfs_write+0x1ce/0x860
 ksys_write+0xe9/0x1b0
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Second to last potentially related work creation:
 kasan_save_stack+0x1b/0x40
 kasan_record_aux_stack+0xa3/0xb0
 insert_work+0x48/0x2e0
 __queue_work+0x4e8/0xdf0
 queue_work_on+0x78/0x80
 tcm_loop_queuecommand+0x1c3/0x4e0 [tcm_loop]
 scsi_queue_rq+0x12ec/0x2d20
 blk_mq_dispatch_rq_list+0x30a/0x1db0
 __blk_mq_do_dispatch_sched+0x326/0x830
 __blk_mq_sched_dispatch_requests+0x2c8/0x3f0
 blk_mq_sched_dispatch_requests+0xca/0x120
 __blk_mq_run_hw_queue+0x93/0xe0
 process_one_work+0x7b6/0x1290
 worker_thread+0x590/0xf80
 kthread+0x362/0x430
 ret_from_fork+0x22/0x30

The buggy address belongs to the object at ffff88814cf79800 which belongs
to the cache tcm_loop_cmd_cache of size 896.

Link: https://lore.kernel.org/r/20210113024508.1264992-1-shinichiro.kawasaki@wdc.com
Fixes: a35129024e ("scsi: target: tcmu: Use priv pointer in se_cmd")
Cc: stable@vger.kernel.org # v5.9+
Acked-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-01-14 21:56:43 -05:00
Linus Torvalds
60f7c503d9 SCSI misc on 20201216
This series consists of the usual driver updates (ufs, qla2xxx,
 smartpqi, target, zfcp, fnic, mpt3sas, ibmvfc) plus a load of
 cleanups, a major power management rework and a load of assorted minor
 updates.  There are a few core updates (formatting fixes being the big
 one) but nothing major this cycle.
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This consists of the usual driver updates (ufs, qla2xxx, smartpqi,
  target, zfcp, fnic, mpt3sas, ibmvfc) plus a load of cleanups, a major
  power management rework and a load of assorted minor updates.

  There are a few core updates (formatting fixes being the big one) but
  nothing major this cycle"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (279 commits)
  scsi: mpt3sas: Update driver version to 36.100.00.00
  scsi: mpt3sas: Handle trigger page after firmware update
  scsi: mpt3sas: Add persistent MPI trigger page
  scsi: mpt3sas: Add persistent SCSI sense trigger page
  scsi: mpt3sas: Add persistent Event trigger page
  scsi: mpt3sas: Add persistent Master trigger page
  scsi: mpt3sas: Add persistent trigger pages support
  scsi: mpt3sas: Sync time periodically between driver and firmware
  scsi: qla2xxx: Update version to 10.02.00.104-k
  scsi: qla2xxx: Fix device loss on 4G and older HBAs
  scsi: qla2xxx: If fcport is undergoing deletion complete I/O with retry
  scsi: qla2xxx: Fix the call trace for flush workqueue
  scsi: qla2xxx: Fix flash update in 28XX adapters on big endian machines
  scsi: qla2xxx: Handle aborts correctly for port undergoing deletion
  scsi: qla2xxx: Fix N2N and NVMe connect retry failure
  scsi: qla2xxx: Fix FW initialization error on big endian machines
  scsi: qla2xxx: Fix crash during driver load on big endian machines
  scsi: qla2xxx: Fix compilation issue in PPC systems
  scsi: qla2xxx: Don't check for fw_started while posting NVMe command
  scsi: qla2xxx: Tear down session if FW say it is down
  ...
2020-12-16 13:34:31 -08:00
Gustavo A. R. Silva
8fdaabe1c9 scsi: target: tcmu: Replace zero-length array with flexible-array member
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-10-29 17:22:59 -05:00
Bodo Stroesser
c8ed1ff88c scsi: target: tcmu: scatter_/gather_data_area() rework
scatter_data_area() and gather_data_area() are not easy to understand since
data is copied in nested loops over sg_list and tcmu dbi list. Since sg
list can contain only partly filled pages, the loop has to be prepared to
handle sg pages not matching dbi pages one by one.

Existing implementation uses kmap_atomic()/kunmap_atomic() due to
performance reasons. But instead of using these calls strictly nested for
sg and dpi pages, the code holds the mappings in an overlapping way, which
indeed is a bug that would trigger on archs using highmem.

The scatterlist lib contains the sg_miter_start/_next/_stop functions which
can be used to simplify such complicated loops.

The new code now processes the dbi list in the outer loop, while sg list is
handled by the inner one. That way the code can take advantage of the
sg_miter_* family calls.

Calling sg_miter_stop() after the end of the inner loop enforces strict
nesting of atomic kmaps.

Since the nested loops in scatter_/gather_data_area were very similar, I
replaced them by the new helper function tcmu_copy_data().

Link: https://lore.kernel.org/r/20201019115118.11949-1-bostroesser@gmail.com
Acked-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-10-26 18:27:44 -04:00
Linus Torvalds
9ff9b0d392 networking changes for the 5.10 merge window
Add redirect_neigh() BPF packet redirect helper, allowing to limit stack
 traversal in common container configs and improving TCP back-pressure.
 Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain.
 
 Expand netlink policy support and improve policy export to user space.
 (Ge)netlink core performs request validation according to declared
 policies. Expand the expressiveness of those policies (min/max length
 and bitmasks). Allow dumping policies for particular commands.
 This is used for feature discovery by user space (instead of kernel
 version parsing or trial and error).
 
 Support IGMPv3/MLDv2 multicast listener discovery protocols in bridge.
 
 Allow more than 255 IPv4 multicast interfaces.
 
 Add support for Type of Service (ToS) reflection in SYN/SYN-ACK
 packets of TCPv6.
 
 In Multi-patch TCP (MPTCP) support concurrent transmission of data
 on multiple subflows in a load balancing scenario. Enhance advertising
 addresses via the RM_ADDR/ADD_ADDR options.
 
 Support SMC-Dv2 version of SMC, which enables multi-subnet deployments.
 
 Allow more calls to same peer in RxRPC.
 
 Support two new Controller Area Network (CAN) protocols -
 CAN-FD and ISO 15765-2:2016.
 
 Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit
 kernel problem.
 
 Add TC actions for implementing MPLS L2 VPNs.
 
 Improve nexthop code - e.g. handle various corner cases when nexthop
 objects are removed from groups better, skip unnecessary notifications
 and make it easier to offload nexthops into HW by converting
 to a blocking notifier.
 
 Support adding and consuming TCP header options by BPF programs,
 opening the doors for easy experimental and deployment-specific
 TCP option use.
 
 Reorganize TCP congestion control (CC) initialization to simplify life
 of TCP CC implemented in BPF.
 
 Add support for shipping BPF programs with the kernel and loading them
 early on boot via the User Mode Driver mechanism, hence reusing all the
 user space infra we have.
 
 Support sleepable BPF programs, initially targeting LSM and tracing.
 
 Add bpf_d_path() helper for returning full path for given 'struct path'.
 
 Make bpf_tail_call compatible with bpf-to-bpf calls.
 
 Allow BPF programs to call map_update_elem on sockmaps.
 
 Add BPF Type Format (BTF) support for type and enum discovery, as
 well as support for using BTF within the kernel itself (current use
 is for pretty printing structures).
 
 Support listing and getting information about bpf_links via the bpf
 syscall.
 
 Enhance kernel interfaces around NIC firmware update. Allow specifying
 overwrite mask to control if settings etc. are reset during update;
 report expected max time operation may take to users; support firmware
 activation without machine reboot incl. limits of how much impact
 reset may have (e.g. dropping link or not).
 
 Extend ethtool configuration interface to report IEEE-standard
 counters, to limit the need for per-vendor logic in user space.
 
 Adopt or extend devlink use for debug, monitoring, fw update
 in many drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw,
 mv88e6xxx, dpaa2-eth).
 
 In mlxsw expose critical and emergency SFP module temperature alarms.
 Refactor port buffer handling to make the defaults more suitable and
 support setting these values explicitly via the DCBNL interface.
 
 Add XDP support for Intel's igb driver.
 
 Support offloading TC flower classification and filtering rules to
 mscc_ocelot switches.
 
 Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as
 fixed interval period pulse generator and one-step timestamping in
 dpaa-eth.
 
 Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3)
 offload.
 
 Add Lynx PHY/PCS MDIO module, and convert various drivers which have
 this HW to use it. Convert mvpp2 to split PCS.
 
 Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as
 7-port Mediatek MT7531 IP.
 
 Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver,
 and wcn3680 support in wcn36xx.
 
 Improve performance for packets which don't require much offloads
 on recent Mellanox NICs by 20% by making multiple packets share
 a descriptor entry.
 
 Move chelsio inline crypto drivers (for TLS and IPsec) from the crypto
 subtree to drivers/net. Move MDIO drivers out of the phy directory.
 
 Clean up a lot of W=1 warnings, reportedly the actively developed
 subsections of networking drivers should now build W=1 warning free.
 
 Make sure drivers don't use in_interrupt() to dynamically adapt their
 code. Convert tasklets to use new tasklet_setup API (sadly this
 conversion is not yet complete).
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:

 - Add redirect_neigh() BPF packet redirect helper, allowing to limit
   stack traversal in common container configs and improving TCP
   back-pressure.

   Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain.

 - Expand netlink policy support and improve policy export to user
   space. (Ge)netlink core performs request validation according to
   declared policies. Expand the expressiveness of those policies
   (min/max length and bitmasks). Allow dumping policies for particular
   commands. This is used for feature discovery by user space (instead
   of kernel version parsing or trial and error).

 - Support IGMPv3/MLDv2 multicast listener discovery protocols in
   bridge.

 - Allow more than 255 IPv4 multicast interfaces.

 - Add support for Type of Service (ToS) reflection in SYN/SYN-ACK
   packets of TCPv6.

 - In Multi-patch TCP (MPTCP) support concurrent transmission of data on
   multiple subflows in a load balancing scenario. Enhance advertising
   addresses via the RM_ADDR/ADD_ADDR options.

 - Support SMC-Dv2 version of SMC, which enables multi-subnet
   deployments.

 - Allow more calls to same peer in RxRPC.

 - Support two new Controller Area Network (CAN) protocols - CAN-FD and
   ISO 15765-2:2016.

 - Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit
   kernel problem.

 - Add TC actions for implementing MPLS L2 VPNs.

 - Improve nexthop code - e.g. handle various corner cases when nexthop
   objects are removed from groups better, skip unnecessary
   notifications and make it easier to offload nexthops into HW by
   converting to a blocking notifier.

 - Support adding and consuming TCP header options by BPF programs,
   opening the doors for easy experimental and deployment-specific TCP
   option use.

 - Reorganize TCP congestion control (CC) initialization to simplify
   life of TCP CC implemented in BPF.

 - Add support for shipping BPF programs with the kernel and loading
   them early on boot via the User Mode Driver mechanism, hence reusing
   all the user space infra we have.

 - Support sleepable BPF programs, initially targeting LSM and tracing.

 - Add bpf_d_path() helper for returning full path for given 'struct
   path'.

 - Make bpf_tail_call compatible with bpf-to-bpf calls.

 - Allow BPF programs to call map_update_elem on sockmaps.

 - Add BPF Type Format (BTF) support for type and enum discovery, as
   well as support for using BTF within the kernel itself (current use
   is for pretty printing structures).

 - Support listing and getting information about bpf_links via the bpf
   syscall.

 - Enhance kernel interfaces around NIC firmware update. Allow
   specifying overwrite mask to control if settings etc. are reset
   during update; report expected max time operation may take to users;
   support firmware activation without machine reboot incl. limits of
   how much impact reset may have (e.g. dropping link or not).

 - Extend ethtool configuration interface to report IEEE-standard
   counters, to limit the need for per-vendor logic in user space.

 - Adopt or extend devlink use for debug, monitoring, fw update in many
   drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw, mv88e6xxx,
   dpaa2-eth).

 - In mlxsw expose critical and emergency SFP module temperature alarms.
   Refactor port buffer handling to make the defaults more suitable and
   support setting these values explicitly via the DCBNL interface.

 - Add XDP support for Intel's igb driver.

 - Support offloading TC flower classification and filtering rules to
   mscc_ocelot switches.

 - Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as
   fixed interval period pulse generator and one-step timestamping in
   dpaa-eth.

 - Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3)
   offload.

 - Add Lynx PHY/PCS MDIO module, and convert various drivers which have
   this HW to use it. Convert mvpp2 to split PCS.

 - Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as
   7-port Mediatek MT7531 IP.

 - Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver,
   and wcn3680 support in wcn36xx.

 - Improve performance for packets which don't require much offloads on
   recent Mellanox NICs by 20% by making multiple packets share a
   descriptor entry.

 - Move chelsio inline crypto drivers (for TLS and IPsec) from the
   crypto subtree to drivers/net. Move MDIO drivers out of the phy
   directory.

 - Clean up a lot of W=1 warnings, reportedly the actively developed
   subsections of networking drivers should now build W=1 warning free.

 - Make sure drivers don't use in_interrupt() to dynamically adapt their
   code. Convert tasklets to use new tasklet_setup API (sadly this
   conversion is not yet complete).

* tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2583 commits)
  Revert "bpfilter: Fix build error with CONFIG_BPFILTER_UMH"
  net, sockmap: Don't call bpf_prog_put() on NULL pointer
  bpf, selftest: Fix flaky tcp_hdr_options test when adding addr to lo
  bpf, sockmap: Add locking annotations to iterator
  netfilter: nftables: allow re-computing sctp CRC-32C in 'payload' statements
  net: fix pos incrementment in ipv6_route_seq_next
  net/smc: fix invalid return code in smcd_new_buf_create()
  net/smc: fix valid DMBE buffer sizes
  net/smc: fix use-after-free of delayed events
  bpfilter: Fix build error with CONFIG_BPFILTER_UMH
  cxgb4/ch_ipsec: Replace the module name to ch_ipsec from chcr
  net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info
  bpf: Fix register equivalence tracking.
  rxrpc: Fix loss of final ack on shutdown
  rxrpc: Fix bundle counting for exclusive connections
  netfilter: restore NF_INET_NUMHOOKS
  ibmveth: Identify ingress large send packets.
  ibmveth: Switch order of ibmveth_helper calls.
  cxgb4: handle 4-tuple PEDIT to NAT mode translation
  selftests: Add VRF route leaking tests
  ...
2020-10-15 18:42:13 -07:00
Jakub Kicinski
66a9b9287d genetlink: move to smaller ops wherever possible
Bulk of the genetlink users can use smaller ops, move them.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02 19:11:11 -07:00
John Donnelly
61741d8699 scsi: target: tcmu: Fix warning: 'page' may be used uninitialized
Corrects drivers/target/target_core_user.c:688:6: warning: 'page' may be
used uninitialized.

Link: https://lore.kernel.org/r/20200924001920.43594-1-john.p.donnelly@oracle.com
Fixes: 3c58f73723 ("scsi: target: tcmu: Optimize use of flush_dcache_page")
Cc: Mike Christie <michael.christie@oracle.com>
Acked-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-10-02 21:22:01 -04:00
Bodo Stroesser
3c9a7c58ea scsi: target: tcmu: Optimize scatter_data_area()
scatter_data_area() has two purposes:

 1) Create the iovs for the data area buffer of a SCSI cmd.

 2) If there is data in DMA_TO_DEVICE direction, copy
    the data from sg_list to data area buffer.

Both are done in a common loop.

In case of DMA_FROM_DEVICE data transfer, scatter_data_area() is called
with parameter copy_data = false. But this flag is just used to skip
memcpy() for data, while radix_tree_lookup still is called for every dbi of
the area area buffer, and kmap and kunmap are called for every page from
sg_list and data_area as well as flush_dcache_page() for the data area
pages.  Since the only thing to do with copy_data = false would be to set
up the iovs, this is a noticeable overhead.  Rework the iov creation in the
main loop of scatter_data_area() providing the new function
new_block_to_iov().  Based on this, create the short new function
tcmu_setup_iovs() that only writes the iovs with no overhead.  This new
function is now called instead of scatter_data_area() for bidi buffers and
for data buffers in those cases where memcpy() would have been skipped.

Link: https://lore.kernel.org/r/20200910155041.17654-4-bstroesser@ts.fujitsu.com
Acked-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-09-22 17:31:43 -04:00
Bodo Stroesser
7e98905e9d scsi: target: tcmu: Optimize queue_cmd_ring()
queue_cmd_ring() needs to check whether there is enough space in cmd ring
and data area for the cmd to queue.

Currently the sequence is:

 1) Calculate size the cmd will occupy on the ring based on estimation of
    needed iovs.

 2) Check whether there is enough space on the ring based on size from 1)

 3) Allocate buffers in data area.

 4) Calculate number of iovs the command really needs while copying
    incoming data (if any) to data area.

 5) Re-calculate real size of cmd on ring based on real number of iovs.

 6) Set up possible padding and cmd on the ring.

Step 1) must not underestimate the cmd size so use max possible number of
iovs for the given I/O data size. The resulting overestimation can be
really high so this sequence is not ideal. The earliest the real number of
iovs can be calculated is after data buffer allocation. Therefore rework
the code to implement the following sequence:

 A) Allocate buffers on data area and calculate number of necessary iovs
    during this.

 B) Calculate real size of cmd on ring based on number of iovs.

 C) Check whether there is enough space on the ring.

 D) Set up possible padding and cmd on the ring.

The new sequence enforces the split of new function tcmu_alloc_data_space()
from is_ring_space_avail(). Using this function, change queue_cmd_ring()
according to the new sequence.

Change routines called by tcmu_alloc_data_space() to allow calculating and
returning the iov count. Remove counting of iovs in scatter_data_area().

Link: https://lore.kernel.org/r/20200910155041.17654-3-bstroesser@ts.fujitsu.com
Acked-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-09-22 17:31:43 -04:00
Bodo Stroesser
52ef2743f1 scsi: target: tcmu: Join tcmu_cmd_get_data_length() and tcmu_cmd_get_block_cnt()
Simplify code by joining tcmu_cmd_get_data_length() and
tcmu_cmd_get_block_cnt() into tcmu_cmd_set_block_cnts().  The new function
sets tcmu_cmd->dbi_cnt and also the new field tcmu_cmd->dbi_bidi_cnt which
is needed for further enhancements in following patches.  Simplify some
code by using tcmu_cmd->dbi(_bidi)_cnt instead of calculation from length.

Please note: The calculation of the number of dbis needed for bidi was
wrong. It was based on the length of the first bidi sg only. I changed it
to correctly sum up entire length of all bidi sgs.

Link: https://lore.kernel.org/r/20200910155041.17654-2-bstroesser@ts.fujitsu.com
Acked-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-09-22 17:31:42 -04:00
Xiongfeng Wang
6d70cb3434 scsi: target: tcmu: Add missing newline when printing parameters
The tcmu 'global_max_data_area_mb' parameter in sysfs is missing a
newline. Add it.

Link: https://lore.kernel.org/r/1599132573-33818-1-git-send-email-wangxiongfeng2@huawei.com
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-09-15 20:19:13 -04:00
Bodo Stroesser
59526d7a18 scsi: target: tcmu: Make TMR notification optional
Add "tmr_notification" configfs attribute to tcmu devices.  If the default
value 0 is used, tcmu only removes aborted commands from qfull_queue.  If
user changes tmr_notification to 1, additionally TMR notifications will be
written to the cmd ring.

Link: https://lore.kernel.org/r/20200726153510.13077-9-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-07-28 22:25:31 -04:00
Bodo Stroesser
bc2d214af5 scsi: target: tcmu: Implement tmr_notify callback
This patch implements the tmr_notify callback for tcmu.  When the callback
is called, tcmu checks the list of aborted commands it received as
parameter:

 - aborted commands in the qfull_queue are removed from the queue and
   target_complete_command is called

 - from the cmd_ids of aborted commands currently uncompleted in cmd ring
   it creates a list of aborted cmd_ids.

Finally a TMR notification is written to cmd ring containing TMR type and
cmd_id list. If there is no space in ring, the TMR notification is queued
on a TMR specific queue.

The TMR specific queue 'tmr_queue' can be seen as a extension of the cmd
ring. At the end of each iexecution of tcmu_complete_commands() we check
whether tmr_queue contains TMRs and try to move them onto the ring. If
tmr_queue is not empty after that, we don't call run_qfull_queue() because
commands must not overtake TMRs.

This way we guarantee that cmd_ids in TMR notification received by
userspace either match an active, not yet completed command or are no
longer valid due to userspace having complete some cmd_ids meanwhile.

New commands that were assigned to an aborted cmd_id will always appear on
the cmd ring _after_ the TMR.

Link: https://lore.kernel.org/r/20200726153510.13077-8-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-07-28 22:25:30 -04:00
Bodo Stroesser
ed212ca878 scsi: target: tcmu: Fix and simplify timeout handling
During cmd timeout handling in check_timedout_devices(), due to a race, it
can happen that tcmu_set_next_deadline() does not start a timer as
expected:

 1) Either tcmu_check_expired_ring_cmd() checks the inflight_queue or
    tcmu_check_expired_queue_cmd() checks the qfull_queue while jiffies has
    the value X

 2) At the end of the check the queue contains one remaining command with
    deadline X (time_after(X, X) is false and thus the command is not
    handled as being timed out).

 3) After tcmu_check_expired_xxxxx_cmd() a timer interrupt happens and
    jiffies is incremented to X+1.

 4) Now tcmu_set_next_deadline() is called, but it skips the command, since
    time_after(X+1, X) is true. Therefore tcmu_set_next_deadline() finds no
    new deadline and stops the timer, which it shouldn't.

Since commands that time out are removed from inflight_queue or
qfull_queue, we don't need the check with time_after() in
tcmu_set_next_deadline() but can use the deadline from the first cmd in
the queue.

Additionally, replace the remaining time_after() calls in
tcmu_check_expired_xxxxx_cmd() with time_after_eq(), because it is not
useful to set the timeout to deadline but then check for jiffies being
greater than deadline.

Simplify the end of tcmu_handle_completions() and change the check for no
more pending commands from

	mb->cmd_tail == mb->cmd_head
to

	idr_is_empty(&udev->commands)

because the old check doesn't work correctly if paddings or in the future
TMRs are in the ring.

Finally tcmu_set_next_deadline() was shifted in the source as
preparation for later implementation of tmr_notify callback.

Link: https://lore.kernel.org/r/20200726153510.13077-7-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-07-28 22:25:29 -04:00
Bodo Stroesser
3d3f9d56a5 scsi: target: tcmu: Factor out new helper ring_insert_padding
The new helper ring_insert_padding is split off from and then called by
queue_cmd_ring. It inserts a padding if necessary.  The new helper will in
a subsequent patch be used during writing of TMR notifications to command
ring.

Link: https://lore.kernel.org/r/20200726153510.13077-6-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-07-28 22:25:28 -04:00
Bodo Stroesser
c968492762 scsi: target: tcmu: Do not queue aborted commands
If tcmu receives an already aborted command, tcmu_queue_cmd() should reject
it.

Link: https://lore.kernel.org/r/20200726153510.13077-5-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-07-28 22:25:28 -04:00
Bodo Stroesser
a35129024e scsi: target: tcmu: Use priv pointer in se_cmd
We initialize and clean up the se_cmd's priv pointer under cmd_ring_lock to
point to the corresponding tcmu_cmd.

In the patch that implements tmr_notify callback in tcmu we will use the
priv pointer.

Link: https://lore.kernel.org/r/20200726153510.13077-4-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-07-28 22:25:27 -04:00
Bodo Stroesser
5a0c256d96 scsi: target: tcmu: Fix crash on ARM during cmd completion
If tcmu_handle_completions() has to process a padding shorter than
sizeof(struct tcmu_cmd_entry), the current call to
tcmu_flush_dcache_range() with sizeof(struct tcmu_cmd_entry) as length
param is wrong and causes crashes on e.g. ARM, because
tcmu_flush_dcache_range() in this case calls
flush_dcache_page(vmalloc_to_page(start)); with start being an invalid
address above the end of the vmalloc'ed area.

The fix is to use the minimum of remaining ring space and sizeof(struct
tcmu_cmd_entry) as the length param.

The patch was tested on kernel 4.19.118.

See https://bugzilla.kernel.org/show_bug.cgi?id=208045#c10

Link: https://lore.kernel.org/r/20200629093756.8947-1-bstroesser@ts.fujitsu.com
Tested-by: JiangYu <lnsyyj@hotmail.com>
Acked-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-06-29 21:44:57 -04:00
Bodo Stroesser
3145550a7f scsi: target: tcmu: Fix crash in tcmu_flush_dcache_range on ARM
This patch fixes the following crash (see
https://bugzilla.kernel.org/show_bug.cgi?id=208045)

 Process iscsi_trx (pid: 7496, stack limit = 0x0000000010dd111a)
 CPU: 0 PID: 7496 Comm: iscsi_trx Not tainted 4.19.118-0419118-generic
        #202004230533
 Hardware name: Greatwall QingTian DF720/F601, BIOS 601FBE20 Sep 26 2019
 pstate: 80400005 (Nzcv daif +PAN -UAO)
 pc : flush_dcache_page+0x18/0x40
 lr : is_ring_space_avail+0x68/0x2f8 [target_core_user]
 sp : ffff000015123a80
 x29: ffff000015123a80 x28: 0000000000000000
 x27: 0000000000001000 x26: ffff000023ea5000
 x25: ffffcfa25bbe08b8 x24: 0000000000000078
 x23: ffff7e0000000000 x22: ffff000023ea5001
 x21: ffffcfa24b79c000 x20: 0000000000000fff
 x19: ffff7e00008fa940 x18: 0000000000000000
 x17: 0000000000000000 x16: ffff2d047e709138
 x15: 0000000000000000 x14: 0000000000000000
 x13: 0000000000000000 x12: ffff2d047fbd0a40
 x11: 0000000000000000 x10: 0000000000000030
 x9 : 0000000000000000 x8 : ffffc9a254820a00
 x7 : 00000000000013b0 x6 : 000000000000003f
 x5 : 0000000000000040 x4 : ffffcfa25bbe08e8
 x3 : 0000000000001000 x2 : 0000000000000078
 x1 : ffffcfa25bbe08b8 x0 : ffff2d040bc88a18
 Call trace:
  flush_dcache_page+0x18/0x40
  is_ring_space_avail+0x68/0x2f8 [target_core_user]
  queue_cmd_ring+0x1f8/0x680 [target_core_user]
  tcmu_queue_cmd+0xe4/0x158 [target_core_user]
  __target_execute_cmd+0x30/0xf0 [target_core_mod]
  target_execute_cmd+0x294/0x390 [target_core_mod]
  transport_generic_new_cmd+0x1e8/0x358 [target_core_mod]
  transport_handle_cdb_direct+0x50/0xb0 [target_core_mod]
  iscsit_execute_cmd+0x2b4/0x350 [iscsi_target_mod]
  iscsit_sequence_cmd+0xd8/0x1d8 [iscsi_target_mod]
  iscsit_process_scsi_cmd+0xac/0xf8 [iscsi_target_mod]
  iscsit_get_rx_pdu+0x404/0xd00 [iscsi_target_mod]
  iscsi_target_rx_thread+0xb8/0x130 [iscsi_target_mod]
  kthread+0x130/0x138
  ret_from_fork+0x10/0x18
 Code: f9000bf3 aa0003f3 aa1e03e0 d503201f (f9400260)
 ---[ end trace 1e451c73f4266776 ]---

The solution is based on patch:

  "scsi: target: tcmu: Optimize use of flush_dcache_page"

which restricts the use of tcmu_flush_dcache_range() to addresses from
vmalloc'ed areas only.

This patch now replaces the virt_to_page() call in
tcmu_flush_dcache_range() - which is wrong for vmalloced addrs - by
vmalloc_to_page().

The patch was tested on ARM with kernel 4.19.118 and 5.7.2

Link: https://lore.kernel.org/r/20200618131632.32748-3-bstroesser@ts.fujitsu.com
Tested-by: JiangYu <lnsyyj@hotmail.com>
Tested-by: Daniel Meyerholt <dxm523@gmail.com>
Acked-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-06-19 23:22:48 -04:00
Bodo Stroesser
3c58f73723 scsi: target: tcmu: Optimize use of flush_dcache_page
(scatter|gather)_data_area() need to flush dcache after writing data to or
before reading data from a page in uio data area.  The two routines are
able to handle data transfer to/from such a page in fragments and flush the
cache after each fragment was copied by calling the wrapper
tcmu_flush_dcache_range().

That means:

1) flush_dcache_page() can be called multiple times for the same page.

2) Calling flush_dcache_page() indirectly using the wrapper does not make
   sense, because each call of the wrapper is for one single page only and
   the calling routine already has the correct page pointer.

Change (scatter|gather)_data_area() such that, instead of calling
tcmu_flush_dcache_range() before/after each memcpy, it now calls
flush_dcache_page() before unmapping a page (when writing is complete for
that page) or after mapping a page (when starting to read the page).

After this change only calls to tcmu_flush_dcache_range() for addresses in
vmalloc'ed command ring are left over.

The patch was tested on ARM with kernel 4.19.118 and 5.7.2

Link: https://lore.kernel.org/r/20200618131632.32748-2-bstroesser@ts.fujitsu.com
Tested-by: JiangYu <lnsyyj@hotmail.com>
Tested-by: Daniel Meyerholt <dxm523@gmail.com>
Acked-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-06-19 23:22:47 -04:00