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  1. 28 Mar, 2019 2 commits
    • Bart Van Assche's avatar
      scsi: sd: Fix a race between closing an sd device and sd I/O · c14a5726
      Bart Van Assche authored 
      The scsi_end_request() function calls scsi_cmd_to_driver() indirectly and
hence needs the disk->private_data pointer. Avoid that that pointer is
cleared before all affected I/O requests have finished. This patch avoids
that the following crash occurs:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Call trace:
 scsi_mq_uninit_cmd+0x1c/0x30
 scsi_end_request+0x7c/0x1b8
 scsi_io_completion+0x464/0x668
 scsi_finish_command+0xbc/0x160
 scsi_eh_flush_done_q+0x10c/0x170
 sas_scsi_recover_host+0x84c/0xa98 [libsas]
 scsi_error_handler+0x140/0x5b0
 kthread+0x100/0x12c
 ret_from_fork+0x10/0x18

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Jason Yan <yanaijie@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Reported-by: default avatarJason Yan <yanaijie@huawei.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      c14a5726
    • zhengbin's avatar
      scsi: core: Run queue when state is set to running after being blocked · 70fc085c
      zhengbin authored 
      Use dd to test a SCSI device:

  1. echo "blocked" >/sys/block/sda/device/state
  2. dd if=/dev/sda of=/mnt/t.log bs=1M count=10
  3. echo "running" >/sys/block/sda/device/state

dd should finish this work after step 3, but it hangs.

After step2, the call chain is this:

blk_mq_dispatch_rq_list-->scsi_queue_rq-->prep_to_mq

prep_to_mq will return BLK_STS_RESOURCE, and scsi_queue_rq will
transition it to BLK_STS_DEV_RESOURCE which means that driver can
guarantee that IO dispatch will be triggered in future when the
resource is available.  Need to follow the rule if we set the device
state to running.

[mkp: tweaked commit description and code comment as suggested by Bart]
Signed-off-by: default avatarzhengbin <zhengbin13@huawei.com>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      70fc085c
  3. 26 Mar, 2019 3 commits
  5. 21 Mar, 2019 2 commits
    • Tyrel Datwyler's avatar
      scsi: ibmvscsi: Fix empty event pool access during host removal · 7f5203c1
      Tyrel Datwyler authored 
      The event pool used for queueing commands is destroyed fairly early in the
ibmvscsi_remove() code path. Since, this happens prior to the call so
scsi_remove_host() it is possible for further calls to queuecommand to be
processed which manifest as a panic due to a NULL pointer dereference as
seen here:

PANIC: "Unable to handle kernel paging request for data at address
0x00000000"

Context process backtrace:

DSISR: 0000000042000000 ????Syscall Result: 0000000000000000
4 [c000000002cb3820] memcpy_power7 at c000000000064204
[Link Register] [c000000002cb3820] ibmvscsi_send_srp_event at d000000003ed14a4
5 [c000000002cb3920] ibmvscsi_send_srp_event at d000000003ed14a4 [ibmvscsi] ?(unreliable)
6 [c000000002cb39c0] ibmvscsi_queuecommand at d000000003ed2388 [ibmvscsi]
7 [c000000002cb3a70] scsi_dispatch_cmd at d00000000395c2d8 [scsi_mod]
8 [c000000002cb3af0] scsi_request_fn at d00000000395ef88 [scsi_mod]
9 [c000000002cb3be0] __blk_run_queue at c000000000429860
10 [c000000002cb3c10] blk_delay_work at c00000000042a0ec
11 [c000000002cb3c40] process_one_work at c0000000000dac30
12 [c000000002cb3cd0] worker_thread at c0000000000db110
13 [c000000002cb3d80] kthread at c0000000000e3378
14 [c000000002cb3e30] ret_from_kernel_thread at c00000000000982c

The kernel buffer log is overfilled with this log:

[11261.952732] ibmvscsi: found no event struct in pool!

This patch reorders the operations during host teardown. Start by calling
the SRP transport and Scsi_Host remove functions to flush any outstanding
work and set the host offline. LLDD teardown follows including destruction
of the event pool, freeing the Command Response Queue (CRQ), and unmapping
any persistent buffers. The event pool destruction is protected by the
scsi_host lock, and the pool is purged prior of any requests for which we
never received a response. Finally, move the removal of the scsi host from
our global list to the end so that the host is easily locatable for
debugging purposes during teardown.

Cc: <stable@vger.kernel.org> # v2.6.12+
Signed-off-by: default avatarTyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      7f5203c1
    • Tyrel Datwyler's avatar
      scsi: ibmvscsi: Protect ibmvscsi_head from concurrent modificaiton · 7205981e
      Tyrel Datwyler authored 
      For each ibmvscsi host created during a probe or destroyed during a remove
we either add or remove that host to/from the global ibmvscsi_head
list. This runs the risk of concurrent modification.

This patch adds a simple spinlock around the list modification calls to
prevent concurrent updates as is done similarly in the ibmvfc driver and
ipr driver.

Fixes: 32d6e4b6 ("scsi: ibmvscsi: add vscsi hosts to global list_head")
Cc: <stable@vger.kernel.org> # v4.10+
Signed-off-by: default avatarTyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      7205981e
  7. 20 Mar, 2019 1 commit
  9. 19 Mar, 2019 4 commits
    • Himanshu Madhani's avatar
      scsi: qla2xxx: Fix NULL pointer crash due to stale CPUID · ac444b4f
      Himanshu Madhani authored 
      This patch fixes crash due to NULL pointer derefrence because CPU pointer
is not set and used by driver.  Instead, driver is passes CPU as tag via
ha->isp_ops->{lun_reset|target_reset}

[   30.160780] qla2xxx [0000:a0:00.1]-8038:9: Cable is unplugged...
[   69.984045] qla2xxx [0000:a0:00.0]-8009:8: DEVICE RESET ISSUED nexus=8:0:0 cmd=00000000b0d62f46.
[   69.992849] BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
[   70.000680] PGD 0 P4D 0
[   70.003232] Oops: 0000 [#1] SMP PTI
[   70.006727] CPU: 2 PID: 6714 Comm: sg_reset Kdump: loaded Not tainted 4.18.0-67.el8.x86_64 #1
[   70.015258] Hardware name: NEC Express5800/T110j [N8100-2758Y]/MX32-PH0-NJ, BIOS F11 02/13/2019
[   70.024016] RIP: 0010:blk_mq_rq_cpu+0x9/0x10
[   70.028315] Code: 01 58 01 00 00 48 83 c0 28 48 3d 80 02 00 00 75 ab c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48
 8b 47 08 <8b> 40 40 c3 0f 1f 00 0f 1f 44 00 00 48 83 ec 10 48 c7 c6 20 6e 7c
[   70.047087] RSP: 0018:ffff99a481487d58 EFLAGS: 00010246
[   70.052322] RAX: 0000000000000000 RBX: ffffffffc041b08b RCX: 0000000000000000
[   70.059466] RDX: 0000000000000000 RSI: ffff8d10b6b16898 RDI: ffff8d10b341e400
[   70.066615] RBP: ffffffffc03a6bd0 R08: 0000000000000415 R09: 0000000000aaaaaa
[   70.073765] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8d10b341e528
[   70.080914] R13: ffff8d10aadefc00 R14: ffff8d0f64efa998 R15: ffff8d0f64efa000
[   70.088083] FS:  00007f90a201e540(0000) GS:ffff8d10b6b00000(0000) knlGS:0000000000000000
[   70.096188] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   70.101959] CR2: 0000000000000040 CR3: 0000000268886005 CR4: 00000000003606e0
[   70.109127] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   70.116277] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   70.123425] Call Trace:
[   70.125896]  __qla2xxx_eh_generic_reset+0xb1/0x220 [qla2xxx]
[   70.131572]  scsi_ioctl_reset+0x1f5/0x2a0
[   70.135600]  scsi_ioctl+0x18e/0x397
[   70.139099]  ? sd_ioctl+0x7c/0x100 [sd_mod]
[   70.143287]  blkdev_ioctl+0x32b/0x9f0
[   70.146954]  ? __check_object_size+0xa3/0x181
[   70.151323]  block_ioctl+0x39/0x40
[   70.154735]  do_vfs_ioctl+0xa4/0x630
[   70.158322]  ? syscall_trace_enter+0x1d3/0x2c0
[   70.162769]  ksys_ioctl+0x60/0x90
[   70.166104]  __x64_sys_ioctl+0x16/0x20
[   70.169859]  do_syscall_64+0x5b/0x1b0
[   70.173532]  entry_SYSCALL_64_after_hwframe+0x65/0xca
[   70.178587] RIP: 0033:0x7f90a1b3445b
[   70.182183] Code: 0f 1e fa 48 8b 05 2d aa 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00
 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d fd a9 2c 00 f7 d8 64 89 01 48
[   70.200956] RSP: 002b:00007fffdca88b68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[   70.208535] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f90a1b3445b
[   70.215684] RDX: 00007fffdca88b84 RSI: 0000000000002284 RDI: 0000000000000003
[   70.222833] RBP: 00007fffdca88ca8 R08: 00007fffdca88b84 R09: 0000000000000000
[   70.229981] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffdca88b84
[   70.237131] R13: 0000000000000000 R14: 000055ab09b0bd28 R15: 0000000000000000
[   70.244284] Modules linked in: nft_chain_route_ipv4 xt_CHECKSUM nft_chain_nat_ipv4 ipt_MASQUERADE nf_nat_ipv4 nf_nat nf_conntrack_ipv4
 nf_defrag_ipv4 xt_conntrack nf_conntrack libcrc32c ipt_REJECT nf_reject_ipv4 nft_counter nft_compat tun bridge stp llc nf_tables nfnetli
nk devlink sunrpc vfat fat intel_rapl intel_pmc_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm wmi_bmof iTCO_wdt iTCO_
vendor_support irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel ipmi_ssif intel_cstate intel_uncore intel_rapl_perf ipmi_si jo
ydev pcspkr ipmi_devintf sg wmi ipmi_msghandler video acpi_power_meter acpi_pad mei_me i2c_i801 mei ip_tables ext4 mbcache jbd2 sr_mod cd
rom sd_mod qla2xxx ast i2c_algo_bit drm_kms_helper nvme_fc syscopyarea sysfillrect uas sysimgblt fb_sys_fops nvme_fabrics ttm
[   70.314805]  usb_storage nvme_core crc32c_intel scsi_transport_fc ahci drm libahci tg3 libata megaraid_sas pinctrl_cannonlake pinctrl_
intel
[   70.327335] CR2: 0000000000000040

Fixes: 9cf2bab6 ("block: kill request ->cpu member")
Signed-off-by: default avatarHimanshu Madhani <hmadhani@marvell.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      ac444b4f
    • Quinn Tran's avatar
      scsi: qla2xxx: Fix FC-AL connection target discovery · 4705f10e
      Quinn Tran authored 
      Commit 7f147f9b ("scsi: qla2xxx: Fix N2N target discovery with Local
loop") fixed N2N target discovery for local loop.  However, same code is
used for FC-AL discovery as well. Added check to make sure we are bypassing
area and domain check only in N2N topology for target discovery.

Fixes: 7f147f9b ("scsi: qla2xxx: Fix N2N target discovery with Local loop")
Cc: stable@vger.kernel.org # 5.0+
Signed-off-by: default avatarQuinn Tran <qtran@marvell.com>
Signed-off-by: default avatarHimanshu Madhani <hmadhani@marvell.com>
Reviewed-by: default avatarEwan D. Milne <emilne@redhat.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      4705f10e
    • Bart Van Assche's avatar
      scsi: core: Avoid that a kernel warning appears during system resume · 17605afa
      Bart Van Assche authored 
      Since scsi_device_quiesce() skips SCSI devices that have another state than
RUNNING, OFFLINE or TRANSPORT_OFFLINE, scsi_device_resume() should not
complain about SCSI devices that have been skipped. Hence this patch.  This
patch avoids that the following warning appears during resume:

WARNING: CPU: 3 PID: 1039 at blk_clear_pm_only+0x2a/0x30
CPU: 3 PID: 1039 Comm: kworker/u8:49 Not tainted 5.0.0+ #1
Hardware name: LENOVO 4180F42/4180F42, BIOS 83ET75WW (1.45 ) 05/10/2013
Workqueue: events_unbound async_run_entry_fn
RIP: 0010:blk_clear_pm_only+0x2a/0x30
Call Trace:
 ? scsi_device_resume+0x28/0x50
 ? scsi_dev_type_resume+0x2b/0x80
 ? async_run_entry_fn+0x2c/0xd0
 ? process_one_work+0x1f0/0x3f0
 ? worker_thread+0x28/0x3c0
 ? process_one_work+0x3f0/0x3f0
 ? kthread+0x10c/0x130
 ? __kthread_create_on_node+0x150/0x150
 ? ret_from_fork+0x1f/0x30

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Martin Steigerwald <martin@lichtvoll.de>
Cc: <stable@vger.kernel.org>
Reported-by: default avatarJisheng Zhang <Jisheng.Zhang@synaptics.com>
Tested-by: default avatarJisheng Zhang <Jisheng.Zhang@synaptics.com>
Fixes: 3a0a5299 ("block, scsi: Make SCSI quiesce and resume work reliably") # v4.15
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      17605afa
    • Bart Van Assche's avatar
      scsi: core: Also call destroy_rcu_head() for passthrough requests · db983f6e
      Bart Van Assche authored 
      cmd->rcu is initialized by scsi_initialize_rq(). For passthrough
requests, blk_get_request() calls scsi_initialize_rq(). For filesystem
requests, scsi_init_command() calls scsi_initialize_rq(). Make sure
that destroy_rcu_head() is called for passthrough requests.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reported-by: default avatarEwan D. Milne <emilne@redhat.com>
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      db983f6e
  11. 18 Mar, 2019 1 commit
    • Maurizio Lombardi's avatar
      scsi: iscsi: flush running unbind operations when removing a session · 165aa2bf
      Maurizio Lombardi authored 
      In some cases, the iscsi_remove_session() function is called while an
unbind_work operation is still running.  This may cause a situation where
sysfs objects are removed in an incorrect order, triggering a kernel
warning.

[  605.249442] ------------[ cut here ]------------
[  605.259180] sysfs group 'power' not found for kobject 'target2:0:0'
[  605.321371] WARNING: CPU: 1 PID: 26794 at fs/sysfs/group.c:235 sysfs_remove_group+0x76/0x80
[  605.341266] Modules linked in: dm_service_time target_core_user target_core_pscsi target_core_file target_core_iblock iscsi_target_mod target_core_mod nls_utf8 isofs ppdev bochs_drm nfit ttm libnvdimm drm_kms_helper syscopyarea sysfillrect sysimgblt joydev pcspkr fb_sys_fops drm i2c_piix4 sg parport_pc parport xfs libcrc32c dm_multipath sr_mod sd_mod cdrom ata_generic 8021q garp mrp ata_piix stp crct10dif_pclmul crc32_pclmul llc libata crc32c_intel virtio_net net_failover ghash_clmulni_intel serio_raw failover sunrpc dm_mirror dm_region_hash dm_log dm_mod be2iscsi bnx2i cnic uio cxgb4i cxgb4 libcxgbi libcxgb qla4xxx iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi
[  605.627479] CPU: 1 PID: 26794 Comm: kworker/u32:2 Not tainted 4.18.0-60.el8.x86_64 #1
[  605.721401] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20180724_192412-buildhw-07.phx2.fedoraproject.org-1.fc29 04/01/2014
[  605.823651] Workqueue: scsi_wq_2 __iscsi_unbind_session [scsi_transport_iscsi]
[  605.830940] RIP: 0010:sysfs_remove_group+0x76/0x80
[  605.922907] Code: 48 89 df 5b 5d 41 5c e9 38 c4 ff ff 48 89 df e8 e0 bf ff ff eb cb 49 8b 14 24 48 8b 75 00 48 c7 c7 38 73 cb a7 e8 24 77 d7 ff <0f> 0b 5b 5d 41 5c c3 0f 1f 00 0f 1f 44 00 00 41 56 41 55 41 54 55
[  606.122304] RSP: 0018:ffffbadcc8d1bda8 EFLAGS: 00010286
[  606.218492] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  606.326381] RDX: ffff98bdfe85eb40 RSI: ffff98bdfe856818 RDI: ffff98bdfe856818
[  606.514498] RBP: ffffffffa7ab73e0 R08: 0000000000000268 R09: 0000000000000007
[  606.529469] R10: 0000000000000000 R11: ffffffffa860d9ad R12: ffff98bdf978e838
[  606.630535] R13: ffff98bdc2cd4010 R14: ffff98bdc2cd3ff0 R15: ffff98bdc2cd4000
[  606.824707] FS:  0000000000000000(0000) GS:ffff98bdfe840000(0000) knlGS:0000000000000000
[  607.018333] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  607.117844] CR2: 00007f84b78ac024 CR3: 000000002c00a003 CR4: 00000000003606e0
[  607.117844] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  607.420926] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  607.524236] Call Trace:
[  607.530591]  device_del+0x56/0x350
[  607.624393]  ? ata_tlink_match+0x30/0x30 [libata]
[  607.727805]  ? attribute_container_device_trigger+0xb4/0xf0
[  607.829911]  scsi_target_reap_ref_release+0x39/0x50
[  607.928572]  scsi_remove_target+0x1a2/0x1d0
[  608.017350]  __iscsi_unbind_session+0xb3/0x160 [scsi_transport_iscsi]
[  608.117435]  process_one_work+0x1a7/0x360
[  608.132917]  worker_thread+0x30/0x390
[  608.222900]  ? pwq_unbound_release_workfn+0xd0/0xd0
[  608.323989]  kthread+0x112/0x130
[  608.418318]  ? kthread_bind+0x30/0x30
[  608.513821]  ret_from_fork+0x35/0x40
[  608.613909] ---[ end trace 0b98c310c8a6138c ]---
Signed-off-by: default avatarMaurizio Lombardi <mlombard@redhat.com>
Acked-by: default avatarChris Leech <cleech@redhat.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      165aa2bf
  13. 17 Mar, 2019 14 commits
  15. 16 Mar, 2019 9 commits
    • Linus Torvalds's avatar
      Merge tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux · a9dce667
      Linus Torvalds authored 
      Pull pidfd system call from Christian Brauner:
 "This introduces the ability to use file descriptors from /proc/<pid>/
  as stable handles on struct pid. Even if a pid is recycled the handle
  will not change. For a start these fds can be used to send signals to
  the processes they refer to.

  With the ability to use /proc/<pid> fds as stable handles on struct
  pid we can fix a long-standing issue where after a process has exited
  its pid can be reused by another process. If a caller sends a signal
  to a reused pid it will end up signaling the wrong process.

  With this patchset we enable a variety of use cases. One obvious
  example is that we can now safely delegate an important part of
  process management - sending signals - to processes other than the
  parent of a given process by sending file descriptors around via scm
  rights and not fearing that the given process will have been recycled
  in the meantime. It also allows for easy testing whether a given
  process is still alive or not by sending signal 0 to a pidfd which is
  quite handy.

  There has been some interest in this feature e.g. from systems
  management (systemd, glibc) and container managers. I have requested
  and gotten comments from glibc to make sure that this syscall is
  suitable for their needs as well. In the future I expect it to take on
  most other pid-based signal syscalls. But such features are left for
  the future once they are needed.

  This has been sitting in linux-next for quite a while and has not
  caused any issues. It comes with selftests which verify basic
  functionality and also test that a recycled pid cannot be signaled via
  a pidfd.

  Jon has written about a prior version of this patchset. It should
  cover the basic functionality since not a lot has changed since then:

      https://lwn.net/Articles/773459/

  The commit message for the syscall itself is extensively documenting
  the syscall, including it's functionality and extensibility"

* tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  selftests: add tests for pidfd_send_signal()
  signal: add pidfd_send_signal() syscall
      a9dce667
    • Linus Torvalds's avatar
      Merge tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm · f67e3fb4
      Linus Torvalds authored 
      Pull device-dax updates from Dan Williams:
 "New device-dax infrastructure to allow persistent memory and other
  "reserved" / performance differentiated memories, to be assigned to
  the core-mm as "System RAM".

  Some users want to use persistent memory as additional volatile
  memory. They are willing to cope with potential performance
  differences, for example between DRAM and 3D Xpoint, and want to use
  typical Linux memory management apis rather than a userspace memory
  allocator layered over an mmap() of a dax file. The administration
  model is to decide how much Persistent Memory (pmem) to use as System
  RAM, create a device-dax-mode namespace of that size, and then assign
  it to the core-mm. The rationale for device-dax is that it is a
  generic memory-mapping driver that can be layered over any "special
  purpose" memory, not just pmem. On subsequent boots udev rules can be
  used to restore the memory assignment.

  One implication of using pmem as RAM is that mlock() no longer keeps
  data off persistent media. For this reason it is recommended to enable
  NVDIMM Security (previously merged for 5.0) to encrypt pmem contents
  at rest. We considered making this recommendation an actively enforced
  requirement, but in the end decided to leave it as a distribution /
  administrator policy to allow for emulation and test environments that
  lack security capable NVDIMMs.

  Summary:

   - Replace the /sys/class/dax device model with /sys/bus/dax, and
     include a compat driver so distributions can opt-in to the new ABI.

   - Allow for an alternative driver for the device-dax address-range

   - Introduce the 'kmem' driver to hotplug / assign a device-dax
     address-range to the core-mm.

   - Arrange for the device-dax target-node to be onlined so that the
     newly added memory range can be uniquely referenced by numa apis"

NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because
we currently have special - and very annoying rules in the kernel about
accessing PMEM only with the "MC safe" accessors, because machine checks
inside the regular repeat string copy functions can be fatal in some
(not described) circumstances.

And apparently the PMEM modules can cause that a lot more than regular
RAM.  The argument is that this happens because PMEM doesn't necessarily
get scrubbed at boot like RAM does, but that is planned to be added for
the user space tooling.

Quoting Dan from another email:
 "The exposure can be reduced in the volatile-RAM case by scanning for
  and clearing errors before it is onlined as RAM. The userspace tooling
  for that can be in place before v5.1-final. There's also runtime
  notifications of errors via acpi_nfit_uc_error_notify() from
  background scrubbers on the DIMM devices. With that mechanism the
  kernel could proactively clear newly discovered poison in the volatile
  case, but that would be additional development more suitable for v5.2.

  I understand the concern, and the need to highlight this issue by
  tapping the brakes on feature development, but I don't see PMEM as RAM
  making the situation worse when the exposure is also there via DAX in
  the PMEM case. Volatile-RAM is arguably a safer use case since it's
  possible to repair pages where the persistent case needs active
  application coordination"

* tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  device-dax: "Hotplug" persistent memory for use like normal RAM
  mm/resource: Let walk_system_ram_range() search child resources
  mm/memory-hotplug: Allow memory resources to be children
  mm/resource: Move HMM pr_debug() deeper into resource code
  mm/resource: Return real error codes from walk failures
  device-dax: Add a 'modalias' attribute to DAX 'bus' devices
  device-dax: Add a 'target_node' attribute
  device-dax: Auto-bind device after successful new_id
  acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node
  device-dax: Add /sys/class/dax backwards compatibility
  device-dax: Add support for a dax override driver
  device-dax: Move resource pinning+mapping into the common driver
  device-dax: Introduce bus + driver model
  device-dax: Start defining a dax bus model
  device-dax: Remove multi-resource infrastructure
  device-dax: Kill dax_region base
  device-dax: Kill dax_region ida
      f67e3fb4
    • Linus Torvalds's avatar
      Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · 477558d7
      Linus Torvalds authored 
      Pull more SCSI updates from James Bottomley:
 "This is the final round of mostly small fixes and performance
  improvements to our initial submit.

  The main regression fix is the ia64 simscsi build failure which was
  missed in the serial number elimination conversion"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (24 commits)
  scsi: ia64: simscsi: use request tag instead of serial_number
  scsi: aacraid: Fix performance issue on logical drives
  scsi: lpfc: Fix error codes in lpfc_sli4_pci_mem_setup()
  scsi: libiscsi: Hold back_lock when calling iscsi_complete_task
  scsi: hisi_sas: Change SERDES_CFG init value to increase reliability of HiLink
  scsi: hisi_sas: Send HARD RESET to clear the previous affiliation of STP target port
  scsi: hisi_sas: Set PHY linkrate when disconnected
  scsi: hisi_sas: print PHY RX errors count for later revision of v3 hw
  scsi: hisi_sas: Fix a timeout race of driver internal and SMP IO
  scsi: hisi_sas: Change return variable type in phy_up_v3_hw()
  scsi: qla2xxx: check for kstrtol() failure
  scsi: lpfc: fix 32-bit format string warning
  scsi: lpfc: fix unused variable warning
  scsi: target: tcmu: Switch to bitmap_zalloc()
  scsi: libiscsi: fall back to sendmsg for slab pages
  scsi: qla2xxx: avoid printf format warning
  scsi: lpfc: resolve static checker warning in lpfc_sli4_hba_unset
  scsi: lpfc: Correct __lpfc_sli_issue_iocb_s4 lockdep check
  scsi: ufs: hisi: fix ufs_hba_variant_ops passing
  scsi: qla2xxx: Fix panic in qla_dfs_tgt_counters_show
  ...
      477558d7
    • Linus Torvalds's avatar
      Merge tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block · 11efae35
      Linus Torvalds authored 
      Pull more block layer changes from Jens Axboe:
 "This is a collection of both stragglers, and fixes that came in after
  I finalized the initial pull. This contains:

   - An MD pull request from Song, with a few minor fixes

   - Set of NVMe patches via Christoph

   - Pull request from Konrad, with a few fixes for xen/blkback

   - pblk fix IO calculation fix (Javier)

   - Segment calculation fix for pass-through (Ming)

   - Fallthrough annotation for blkcg (Mathieu)"

* tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block: (25 commits)
  blkcg: annotate implicit fall through
  nvme-tcp: support C2HData with SUCCESS flag
  nvmet: ignore EOPNOTSUPP for discard
  nvme: add proper write zeroes setup for the multipath device
  nvme: add proper discard setup for the multipath device
  nvme: remove nvme_ns_config_oncs
  nvme: disable Write Zeroes for qemu controllers
  nvmet-fc: bring Disconnect into compliance with FC-NVME spec
  nvmet-fc: fix issues with targetport assoc_list list walking
  nvme-fc: reject reconnect if io queue count is reduced to zero
  nvme-fc: fix numa_node when dev is null
  nvme-fc: use nr_phys_segments to determine existence of sgl
  nvme-loop: init nvmet_ctrl fatal_err_work when allocate
  nvme: update comment to make the code easier to read
  nvme: put ns_head ref if namespace fails allocation
  nvme-trace: fix cdw10 buffer overrun
  nvme: don't warn on block content change effects
  nvme: add get-feature to admin cmds tracer
  md: Fix failed allocation of md_register_thread
  It's wrong to add len to sector_nr in raid10 reshape twice
  ...
      11efae35
    • Linus Torvalds's avatar
      Merge tag 'nfs-for-5.1-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs · 465c209d
      Linus Torvalds authored 
      Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

  Bugfixes:
   - Fix an Oops in SUNRPC back channel tracepoints
   - Fix a SUNRPC client regression when handling oversized replies
   - Fix the minimal size for SUNRPC reply buffer allocation
   - rpc_decode_header() must always return a non-zero value on error
   - Fix a typo in pnfs_update_layout()

  Cleanup:
   - Remove redundant check for the reply length in call_decode()"

* tag 'nfs-for-5.1-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: Remove redundant check for the reply length in call_decode()
  SUNRPC: Handle the SYSTEM_ERR rpc error
  SUNRPC: rpc_decode_header() must always return a non-zero value on error
  SUNRPC: Use the ENOTCONN error on socket disconnect
  SUNRPC: Fix the minimal size for reply buffer allocation
  SUNRPC: Fix a client regression when handling oversized replies
  pNFS: Fix a typo in pnfs_update_layout
  fix null pointer deref in tracepoints in back channel
      465c209d
    • Linus Torvalds's avatar
      Merge tag 'powerpc-5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · a9c55d58
      Linus Torvalds authored 
      Pull powerpc fixes from Michael Ellerman:
 "One fix to prevent runtime allocation of 16GB pages when running in a
  VM (as opposed to bare metal), because it doesn't work.

  A small fix to our recently added KCOV support to exempt some more
  code from being instrumented.

  Plus a few minor build fixes, a small dead code removal and a
  defconfig update.

  Thanks to: Alexey Kardashevskiy, Aneesh Kumar K.V, Christophe Leroy,
  Jason Yan, Joel Stanley, Mahesh Salgaonkar, Mathieu Malaterre"

* tag 'powerpc-5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Include <asm/nmi.h> header file to fix a warning
  powerpc/powernv: Fix compile without CONFIG_TRACEPOINTS
  powerpc/mm: Disable kcov for SLB routines
  powerpc: remove dead code in head_fsl_booke.S
  powerpc/configs: Sync skiroot defconfig
  powerpc/hugetlb: Don't do runtime allocation of 16G pages in LPAR configuration
      a9c55d58
    • Linus Torvalds's avatar
      Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · 92497350
      Linus Torvalds authored 
      Pull vfs mount infrastructure fix from Al Viro:
 "Fixup for sysfs braino.

  Capabilities checks for sysfs mount do include those on netns, but
  only if CONFIG_NET_NS is enabled. Sorry, should've caught that
  earlier..."

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix sysfs_init_fs_context() in !CONFIG_NET_NS case
      92497350
    • Al Viro's avatar
      fix sysfs_init_fs_context() in !CONFIG_NET_NS case · ab81dabd
      Al Viro authored 
      Permission checks on current's netns should be done only when
netns are enabled.
Reported-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
Fixes: 23bf1b6bSigned-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      ab81dabd
    • Linus Torvalds's avatar
      Merge tag '5.1-rc-smb3' of git://git.samba.org/sfrench/cifs-2.6 · 9c7dc824
      Linus Torvalds authored 
      Pull more smb3 updates from Steve French:
 "Various tracing and debugging improvements, crediting fixes, some
  cleanup, and important fallocate fix (fixes three xfstests) and lock
  fix.

  Summary:

   - Various additional dynamic tracing tracepoints

   - Debugging improvements (including ability to query the server via
     SMB3 fsctl from userspace tools which can help with stats and
     debugging)

   - One minor performance improvement (root directory inode caching)

   - Crediting (SMB3 flow control) fixes

   - Some cleanup (docs and to mknod)

   - Important fixes: one to smb3 implementation of fallocate zero range
     (which fixes three xfstests) and a POSIX lock fix"

* tag '5.1-rc-smb3' of git://git.samba.org/sfrench/cifs-2.6: (22 commits)
  CIFS: fix POSIX lock leak and invalid ptr deref
  SMB3: Allow SMB3 FSCTL queries to be sent to server from tools
  cifs: fix incorrect handling of smb2_set_sparse() return in smb3_simple_falloc
  smb2: fix typo in definition of a few error flags
  CIFS: make mknod() an smb_version_op
  cifs: minor documentation updates
  cifs: remove unused value pointed out by Coverity
  SMB3: passthru query info doesn't check for SMB3 FSCTL passthru
  smb3: add dynamic tracepoints for simple fallocate and zero range
  cifs: fix smb3_zero_range so it can expand the file-size when required
  cifs: add SMB2_ioctl_init/free helpers to be used with compounding
  smb3: Add dynamic trace points for various compounded smb3 ops
  cifs: cache FILE_ALL_INFO for the shared root handle
  smb3: display volume serial number for shares in /proc/fs/cifs/DebugData
  cifs: simplify how we handle credits in compound_send_recv()
  smb3: add dynamic tracepoint for timeout waiting for credits
  smb3: display security information in /proc/fs/cifs/DebugData more accurately
  cifs: add a timeout argument to wait_for_free_credits
  cifs: prevent starvation in wait_for_free_credits for multi-credit requests
  cifs: wait_for_free_credits() make it possible to wait for >=1 credits
  ...
      9c7dc824
  17. 15 Mar, 2019 4 commits
    • Linus Torvalds's avatar
      Merge branch 'for-linus-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml · 6c83d0d5
      Linus Torvalds authored 
      Pull UML updates from Richard Weinberger:
 "Bugfix for the UML block device driver"

* 'for-linus-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Fix for a possible OOPS in ubd initialization
  um: Remove duplicated include from vector_user.c
      6c83d0d5
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · 636deed6
      Linus Torvalds authored 
      Pull KVM updates from Paolo Bonzini:
 "ARM:
   - some cleanups
   - direct physical timer assignment
   - cache sanitization for 32-bit guests

  s390:
   - interrupt cleanup
   - introduction of the Guest Information Block
   - preparation for processor subfunctions in cpu models

  PPC:
   - bug fixes and improvements, especially related to machine checks
     and protection keys

  x86:
   - many, many cleanups, including removing a bunch of MMU code for
     unnecessary optimizations
   - AVIC fixes

  Generic:
   - memcg accounting"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (147 commits)
  kvm: vmx: fix formatting of a comment
  KVM: doc: Document the life cycle of a VM and its resources
  MAINTAINERS: Add KVM selftests to existing KVM entry
  Revert "KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()"
  KVM: PPC: Book3S: Add count cache flush parameters to kvmppc_get_cpu_char()
  KVM: PPC: Fix compilation when KVM is not enabled
  KVM: Minor cleanups for kvm_main.c
  KVM: s390: add debug logging for cpu model subfunctions
  KVM: s390: implement subfunction processor calls
  arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2
  KVM: arm/arm64: Remove unused timer variable
  KVM: PPC: Book3S: Improve KVM reference counting
  KVM: PPC: Book3S HV: Fix build failure without IOMMU support
  Revert "KVM: Eliminate extra function calls in kvm_get_dirty_log_protect()"
  x86: kvmguest: use TSC clocksource if invariant TSC is exposed
  KVM: Never start grow vCPU halt_poll_ns from value below halt_poll_ns_grow_start
  KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter
  KVM: grow_halt_poll_ns() should never shrink vCPU halt_poll_ns
  KVM: x86/mmu: Consolidate kvm_mmu_zap_all() and kvm_mmu_zap_mmio_sptes()
  KVM: x86/mmu: WARN if zapping a MMIO spte results in zapping children
  ...
      636deed6
    • Linus Torvalds's avatar
      Merge tag 'trace-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace · aa2e3ac6
      Linus Torvalds authored 
      Pull tracing fixes and cleanups from Steven Rostedt:
 "This contains a series of last minute clean ups, small fixes and error
  checks"

* tag 'trace-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/probe: Verify alloc_trace_*probe() result
  tracing/probe: Check event/group naming rule at parsing
  tracing/probe: Check the size of argument name and body
  tracing/probe: Check event name length correctly
  tracing/probe: Check maxactive error cases
  tracing: kdb: Fix ftdump to not sleep
  trace/probes: Remove kernel doc style from non kernel doc comment
  tracing/probes: Make reserved_field_names static
      aa2e3ac6
    • Linus Torvalds's avatar
      Merge tag 'iommu-fix-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu · 323ea40f
      Linus Torvalds authored 
      Pull IOMMU fix from Joerg Roedel:
 "Fix a NULL-pointer dereference issue in the ACPI device matching code
  of the AMD IOMMU driver"

* tag 'iommu-fix-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Fix NULL dereference bug in match_hid_uid
      323ea40f
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