[Group.of.nepali.translators] [Bug 1774336] Re: FS-Cache: Assertion failed: FS-Cache: 6 == 5 is false

2018-07-26 Thread Launchpad Bug Tracker 
This bug was fixed in the package linux - 4.15.0-29.31

---
linux (4.15.0-29.31) bionic; urgency=medium

  * linux: 4.15.0-29.31 -proposed tracker (LP: #1782173)

  * [SRU Bionic][Cosmic] kernel panic in ipmi_ssif at msg_done_handler
(LP: #116)
- ipmi_ssif: Fix kernel panic at msg_done_handler

  * Update to ocxl driver for 18.04.1 (LP: #1775786)
- misc: ocxl: use put_device() instead of device_unregister()
- powerpc: Add TIDR CPU feature for POWER9
- powerpc: Use TIDR CPU feature to control TIDR allocation
- powerpc: use task_pid_nr() for TID allocation
- ocxl: Rename pnv_ocxl_spa_remove_pe to clarify it's action
- ocxl: Expose the thread_id needed for wait on POWER9
- ocxl: Add an IOCTL so userspace knows what OCXL features are available
- ocxl: Document new OCXL IOCTLs
- ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait()

  * Critical upstream bugfix missing in Ubuntu 18.04 - frequent Xorg crash after
suspend (LP: #1776887)
- ocxl: Document the OCXL_IOCTL_GET_METADATA IOCTL

  * Hard LOCKUP observed on stressing Ubuntu 18 04 (LP: #1777194)
- powerpc: use NMI IPI for smp_send_stop
- powerpc: Fix smp_send_stop NMI IPI handling

  * IPL: ppc64_cpu --frequency hang with INFO: rcu_sched detected stalls on
CPUs/tasks on w34 and wsbmc016 with 920.1714.20170330n (LP: #1773964)
- rtc: opal: Fix OPAL RTC driver OPAL_BUSY loops

  * [Regression] EXT4-fs error (device sda2): ext4_validate_block_bitmap:383:
comm stress-ng: bg 4705: bad block bitmap checksum (LP: #1781709)
- SAUCE: Revert "UBUNTU: SAUCE: ext4: fix ext4_validate_inode_bitmap: comm
  stress-ng: Corrupt inode bitmap"
- SAUCE: ext4: check for allocation block validity with block group locked

linux (4.15.0-28.30) bionic; urgency=medium

  * linux: 4.15.0-28.30 -proposed tracker (LP: #1781433)

  * Cannot set MTU higher than 1500 in Xen instance (LP: #1781413)
- xen-netfront: Fix mismatched rtnl_unlock
- xen-netfront: Update features after registering netdev

linux (4.15.0-27.29) bionic; urgency=medium

  * linux: 4.15.0-27.29 -proposed tracker (LP: #1781062)

  * [Regression] EXT4-fs error (device sda1): ext4_validate_inode_bitmap:99:
comm stress-ng: Corrupt inode bitmap (LP: #1780137)
- SAUCE: ext4: fix ext4_validate_inode_bitmap: comm stress-ng: Corrupt inode
  bitmap

linux (4.15.0-26.28) bionic; urgency=medium

  * linux: 4.15.0-26.28 -proposed tracker (LP: #1780112)

  * failure to boot with linux-image-4.15.0-24-generic (LP: #1779827) // Cloud-
init causes potentially huge boot delays with 4.15 kernels (LP: #1780062)
- random: Make getrandom() ready earlier

linux (4.15.0-25.27) bionic; urgency=medium

  * linux: 4.15.0-25.27 -proposed tracker (LP: #1779354)

  * hisi_sas_v3_hw: internal task abort: timeout and not done. (LP: #136)
- scsi: hisi_sas: Update a couple of register settings for v3 hw

  * hisi_sas: Add missing PHY spinlock init (LP: #134)
- scsi: hisi_sas: Add missing PHY spinlock init

  * hisi_sas: improve read performance by pre-allocating slot DMA buffers
(LP: #127)
- scsi: hisi_sas: use dma_zalloc_coherent()
- scsi: hisi_sas: Use dmam_alloc_coherent()
- scsi: hisi_sas: Pre-allocate slot DMA buffers

  * hisi_sas: Failures during host reset (LP: #1777696)
- scsi: hisi_sas: Only process broadcast change in phy_bcast_v3_hw()
- scsi: hisi_sas: Fix the conflict between dev gone and host reset
- scsi: hisi_sas: Adjust task reject period during host reset
- scsi: hisi_sas: Add a flag to filter PHY events during reset
- scsi: hisi_sas: Release all remaining resources in clear nexus ha

  * Fake SAS addresses for SATA disks on HiSilicon D05 are non-unique
(LP: #1776750)
- scsi: hisi_sas: make SAS address of SATA disks unique

  * Vcs-Git header on bionic linux source package points to zesty git tree
(LP: #1766055)
- [Packaging]: Update Vcs-Git

  * large KVM instances run out of IRQ routes (LP: #1778261)
- SAUCE: kvm -- increase KVM_MAX_IRQ_ROUTES to 2048 on x86

 -- Stefan Bader   Tue, 17 Jul 2018 10:57:50
+0200

** Changed in: linux (Ubuntu)
   Status: Confirmed => Fix Released

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Title:
  FS-Cache: Assertion failed: FS-Cache: 6 == 5 is false

Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Trusty:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Artful:
  Fix Released
Status in linux source package in Bionic:
  Fix Released

Bug description:
  == SRU Justification ==

  [Impact]
  Oops during heavy NFS + FSCache use:

  [81738.886634] FS-Cache: 
  [81738.888281] FS-Cache: Assertion failed
  [81738.889461] FS-Cache: 6 == 5

[Group.of.nepali.translators] [Bug 1774336] Re: FS-Cache: Assertion failed: FS-Cache: 6 == 5 is false

2018-07-02 Thread Launchpad Bug Tracker 
This bug was fixed in the package linux - 3.13.0-153.203

---
linux (3.13.0-153.203) trusty; urgency=medium

  * linux: 3.13.0-153.203 -proposed tracker (LP: #1776819)

  * CVE-2018-3665 (x86)
- x86/fpu: Print out whether we are doing lazy/eager FPU context switches
- x86/fpu: Default eagerfpu=on on all CPUs
- x86/fpu: Fix math emulation in eager fpu mode

linux (3.13.0-152.202) trusty; urgency=medium

  * linux: 3.13.0-152.202 -proposed tracker (LP: #1776350)

  * CVE-2017-15265
- ALSA: seq: Fix use-after-free at creating a port

  * register on binfmt_misc may overflow and crash the system (LP: #1775856)
- fs/binfmt_misc.c: do not allow offset overflow

  * CVE-2018-1130
- dccp: check sk for closed state in dccp_sendmsg()
- ipv6: dccp: add missing bind_conflict to dccp_ipv6_mapped

  * add_key04 in LTP syscall test cause kernel oops (NULL pointer dereference)
with T kernel (LP: #1775316) // CVE-2017-12193
- assoc_array: Fix a buggy node-splitting case

  * CVE-2017-12154
- kvm: nVMX: Don't allow L2 to access the hardware CR8

  * CVE-2018-7757
- scsi: libsas: fix memory leak in sas_smp_get_phy_events()

  * CVE-2018-6927
- futex: Prevent overflow by strengthen input validation

  * FS-Cache: Assertion failed: FS-Cache: 6 == 5 is false (LP: #1774336)
- SAUCE: CacheFiles: fix a read_waiter/read_copier race

  * CVE-2018-5803
- sctp: verify size of a new chunk in _sctp_make_chunk()

  * WARNING: CPU: 28 PID: 34085 at /build/linux-
90Gc2C/linux-3.13.0/net/core/dev.c:1433 dev_disable_lro+0x87/0x90()
(LP: #1771480)
- net/core: generic support for disabling netdev features down stack
- SAUCE: Backport helper function netdev_upper_get_next_dev_rcu

  * CVE-2018-7755
- SAUCE: floppy: Do not copy a kernel pointer to user memory in FDGETPRM 
ioctl

  * CVE-2018-5750
- ACPI: sbshc: remove raw pointer from printk() message

 -- Stefan Bader   Thu, 14 Jun 2018 07:00:42
+0200

** Changed in: linux (Ubuntu Bionic)
   Status: Fix Committed => Fix Released

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Title:
  FS-Cache: Assertion failed: FS-Cache: 6 == 5 is false

Status in linux package in Ubuntu:
  Confirmed
Status in linux source package in Trusty:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Artful:
  Fix Released
Status in linux source package in Bionic:
  Fix Released

Bug description:
  == SRU Justification ==

  [Impact]
  Oops during heavy NFS + FSCache use:

  [81738.886634] FS-Cache: 
  [81738.888281] FS-Cache: Assertion failed
  [81738.889461] FS-Cache: 6 == 5 is false
  [81738.890625] [ cut here ]
  [81738.891706] kernel BUG at 
/build/linux-hVVhWi/linux-4.4.0/fs/fscache/operation.c:494!

  6 == 5 represents an operation being DEAD when it was not expected to
  be.

  [Cause]
  There is a race in fscache and cachefiles. 

  One thread is in cachefiles_read_waiter:
   1) object->work_lock is taken.
   2) the operation is added to the to_do list.
   3) the work lock is dropped.
   4) fscache_enqueue_retrieval is called, which takes a reference.

  Another thread is in cachefiles_read_copier:
   1) object->work_lock is taken
   2) an item is popped off the to_do list.
   3) object->work_lock is dropped.
   4) some processing is done on the item, and fscache_put_retrieval() is 
called, dropping a reference.

  Now if the this process in cachefiles_read_copier takes place
  *between* steps 3 and 4 in cachefiles_read_waiter, a reference will be
  dropped before it is taken, which leads to the objects reference count
  hitting zero, which leads to lifecycle events for the object happening
  too soon, leading to the assertion failure later on.

  (This is simplified and clarified from the original upstream analysis
  for this patch at https://www.redhat.com/archives/linux-
  cachefs/2018-February/msg1.html and from a similar patch with a
  different approach to fixing the bug at
  https://www.redhat.com/archives/linux-cachefs/2017-June/msg2.html)

  [Fix]
  Move fscache_enqueue_retrieval under the lock in cachefiles_read_waiter. This 
means that the object cannot be popped off the to_do list until it is in a 
fully consistent state with the reference taken.

  [Testcase]
  A user has run ~100 hours of NFS stress tests and not seen this bug recur.

  [Regression Potential]
   - Limited to fscache/cachefiles. 
   - The change makes things more conservative (doing more under lock) so 
that's reassuring. 
   - There may be performance impacts but none have been observed so far.

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[Group.of.nepali.translators] [Bug 1774336] Re: FS-Cache: Assertion failed: FS-Cache: 6 == 5 is false

2018-07-02 Thread Launchpad Bug Tracker 
This bug was fixed in the package linux - 4.13.0-46.51

---
linux (4.13.0-46.51) artful; urgency=medium

  * linux: 4.13.0-46.51 -proposed tracker (LP: #1776333)

  * register on binfmt_misc may overflow and crash the system (LP: #1775856)
- fs/binfmt_misc.c: do not allow offset overflow

  * CVE-2018-11508
- compat: fix 4-byte infoleak via uninitialized struct field

  * rfi-flush: Switch to new linear fallback flush (LP: #1744173)
- SAUCE: rfi-flush: Factor out init_fallback_flush()
- SAUCE: rfi-flush: Move rfi_flush_fallback_area to end of paca
- powerpc/64s: Improve RFI L1-D cache flush fallback
- powerpc/rfi-flush: Make it possible to call setup_rfi_flush() again
- powerpc/rfi-flush: Differentiate enabled and patched flush types
- powerpc/rfi-flush: Call setup_rfi_flush() after LPM migration

  * Fix enabling bridge MMIO windows (LP: #1771344)
- powerpc/eeh: Fix enabling bridge MMIO windows

  * CVE-2018-1130
- dccp: check sk for closed state in dccp_sendmsg()

  * CVE-2018-7757
- scsi: libsas: fix memory leak in sas_smp_get_phy_events()

  * cpum_sf: ensure sample freq is non-zero (LP: #1772593)
- s390/cpum_sf: ensure sample frequency of perf event attributes is non-zero

  * wlp3s0: failed to remove key (1, ff:ff:ff:ff:ff:ff) from hardware (-22)
(LP: #1720930)
- iwlwifi: mvm: fix "failed to remove key" message

  * CVE-2018-6927
- futex: Prevent overflow by strengthen input validation

  * After update to 4.13-43 Intel Graphics are Laggy (LP: #1773520)
- SAUCE: Revert "drm/i915/edp: Allow alternate fixed mode for eDP if
  available."

  * ELANPAD ELAN0612 does not work, patch available (LP: #1773509)
- SAUCE: Input: elan_i2c - add ELAN0612 to the ACPI table

  * kernel backtrace when receiving large UDP packages (LP: #1772031)
- iov_iter: fix page_copy_sane for compound pages

  * FS-Cache: Assertion failed: FS-Cache: 6 == 5 is false (LP: #1774336)
- SAUCE: CacheFiles: fix a read_waiter/read_copier race

  * CVE-2018-5803
- sctp: verify size of a new chunk in _sctp_make_chunk()

  * enable mic-mute hotkey and led on Lenovo M820z and M920z (LP: #1774306)
- ALSA: hda/realtek - Enable mic-mute hotkey for several Lenovo AIOs

  * CVE-2018-7755
- SAUCE: floppy: Do not copy a kernel pointer to user memory in FDGETPRM 
ioctl

  * CVE-2018-5750
- ACPI: sbshc: remove raw pointer from printk() message

 -- Khalid Elmously   Mon, 11 Jun 2018
23:25:30 +

** Changed in: linux (Ubuntu Artful)
   Status: Fix Committed => Fix Released

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2018-1130

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2018-11508

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2018-5750

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2018-5803

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2018-6927

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2018-7755

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2018-7757

** Changed in: linux (Ubuntu Trusty)
   Status: Fix Committed => Fix Released

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2017-12154

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2017-12193

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2017-15265

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2018-3665

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https://bugs.launchpad.net/bugs/1774336

Title:
  FS-Cache: Assertion failed: FS-Cache: 6 == 5 is false

Status in linux package in Ubuntu:
  Confirmed
Status in linux source package in Trusty:
  Fix Released
Status in linux source package in Xenial:
  Fix Released
Status in linux source package in Artful:
  Fix Released
Status in linux source package in Bionic:
  Fix Released

Bug description:
  == SRU Justification ==

  [Impact]
  Oops during heavy NFS + FSCache use:

  [81738.886634] FS-Cache: 
  [81738.888281] FS-Cache: Assertion failed
  [81738.889461] FS-Cache: 6 == 5 is false
  [81738.890625] [ cut here ]
  [81738.891706] kernel BUG at 
/build/linux-hVVhWi/linux-4.4.0/fs/fscache/operation.c:494!

  6 == 5 represents an operation being DEAD when it was not expected to
  be.

  [Cause]
  There is a race in fscache and cachefiles. 

  One thread is in cachefiles_read_waiter:
   1) object->work_lock is taken.
   2) the operation is added to the to_do list.
   3) the work lock is dropped.
   4) fscache_enqueue_retrieval is called, which takes a reference.

  Another thread is in cachefiles_read_copier:
   1) object->work_lock is taken
   2) an item is popped off the to_do list.
   3) object->work_lock is dropped.
   4) some processing is done on the item, and fscache_put_retrieval() is 
called, dropping a

[Group.of.nepali.translators] [Bug 1774336] Re: FS-Cache: Assertion failed: FS-Cache: 6 == 5 is false

2018-07-02 Thread Launchpad Bug Tracker 
This bug was fixed in the package linux - 4.15.0-24.26

---
linux (4.15.0-24.26) bionic; urgency=medium

  * linux: 4.15.0-24.26 -proposed tracker (LP: #1776338)

  * Bionic update: upstream stable patchset 2018-06-06 (LP: #1775483)
- drm: bridge: dw-hdmi: Fix overflow workaround for Amlogic Meson GX SoCs
- i40e: Fix attach VF to VM issue
- tpm: cmd_ready command can be issued only after granting locality
- tpm: tpm-interface: fix tpm_transmit/_cmd kdoc
- tpm: add retry logic
- Revert "ath10k: send (re)assoc peer command when NSS changed"
- bonding: do not set slave_dev npinfo before slave_enable_netpoll in
  bond_enslave
- ipv6: add RTA_TABLE and RTA_PREFSRC to rtm_ipv6_policy
- ipv6: sr: fix NULL pointer dereference in seg6_do_srh_encap()- v4 pkts
- KEYS: DNS: limit the length of option strings
- l2tp: check sockaddr length in pppol2tp_connect()
- net: validate attribute sizes in neigh_dump_table()
- llc: delete timers synchronously in llc_sk_free()
- tcp: don't read out-of-bounds opsize
- net: af_packet: fix race in PACKET_{R|T}X_RING
- tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets
- net: fix deadlock while clearing neighbor proxy table
- team: avoid adding twice the same option to the event list
- net/smc: fix shutdown in state SMC_LISTEN
- team: fix netconsole setup over team
- packet: fix bitfield update race
- tipc: add policy for TIPC_NLA_NET_ADDR
- pppoe: check sockaddr length in pppoe_connect()
- vlan: Fix reading memory beyond skb->tail in skb_vlan_tagged_multi
- amd-xgbe: Add pre/post auto-negotiation phy hooks
- sctp: do not check port in sctp_inet6_cmp_addr
- amd-xgbe: Improve KR auto-negotiation and training
- strparser: Do not call mod_delayed_work with a timeout of LONG_MAX
- amd-xgbe: Only use the SFP supported transceiver signals
- strparser: Fix incorrect strp->need_bytes value.
- net: sched: ife: signal not finding metaid
- tcp: clear tp->packets_out when purging write queue
- net: sched: ife: handle malformed tlv length
- net: sched: ife: check on metadata length
- llc: hold llc_sap before release_sock()
- llc: fix NULL pointer deref for SOCK_ZAPPED
- net: ethernet: ti: cpsw: fix tx vlan priority mapping
- virtio_net: split out ctrl buffer
- virtio_net: fix adding vids on big-endian
- KVM: s390: force bp isolation for VSIE
- s390: correct module section names for expoline code revert
- microblaze: Setup dependencies for ASM optimized lib functions
- commoncap: Handle memory allocation failure.
- scsi: mptsas: Disable WRITE SAME
- cdrom: information leak in cdrom_ioctl_media_changed()
- m68k/mac: Don't remap SWIM MMIO region
- block/swim: Check drive type
- block/swim: Don't log an error message for an invalid ioctl
- block/swim: Remove extra put_disk() call from error path
- block/swim: Rename macros to avoid inconsistent inverted logic
- block/swim: Select appropriate drive on device open
- block/swim: Fix array bounds check
- block/swim: Fix IO error at end of medium
- tracing: Fix missing tab for hwlat_detector print format
- s390/cio: update chpid descriptor after resource accessibility event
- s390/dasd: fix IO error for newly defined devices
- s390/uprobes: implement arch_uretprobe_is_alive()
- ACPI / video: Only default only_lcd to true on Win8-ready _desktops_
- docs: ip-sysctl.txt: fix name of some ipv6 variables
- net: mvpp2: Fix DMA address mask size
- net: stmmac: Disable ACS Feature for GMAC >= 4
- l2tp: hold reference on tunnels in netlink dumps
- l2tp: hold reference on tunnels printed in pppol2tp proc file
- l2tp: hold reference on tunnels printed in l2tp/tunnels debugfs file
- l2tp: fix {pppol2tp, l2tp_dfs}_seq_stop() in case of seq_file overflow
- s390/qeth: fix error handling in adapter command callbacks
- s390/qeth: avoid control IO completion stalls
- s390/qeth: handle failure on workqueue creation
- bnxt_en: Fix memory fault in bnxt_ethtool_init()
- virtio-net: add missing virtqueue kick when flushing packets
- VSOCK: make af_vsock.ko removable again
- hwmon: (k10temp) Add temperature offset for Ryzen 2700X
- hwmon: (k10temp) Add support for AMD Ryzen w/ Vega graphics
- s390/cpum_cf: rename IBM z13/z14 counter names
- kprobes: Fix random address output of blacklist file
- Revert "pinctrl: intel: Initialize GPIO properly when used through 
irqchip"

  * Lenovo V330 needs patch in ideapad_laptop module for rfkill (LP: #1774636)
- SAUCE: Add Lenovo V330 to the ideapad_laptop rfkill blacklist

  * bluetooth controller fail after suspend with USB autosuspend on XPS 13 9360
(LP: #1775217)
- Bluetooth: btusb: Add Dell XPS 13 9360 to btusb_needs_reset_resume_table

  * [Hyper-V] PCI: hv: Fix 2 hang issues in

[Group.of.nepali.translators] [Bug 1774336] Re: FS-Cache: Assertion failed: FS-Cache: 6 == 5 is false

2018-06-07 Thread Kleber Sacilotto de Souza 
** Also affects: linux (Ubuntu Artful)
   Importance: Undecided
   Status: New

** Also affects: linux (Ubuntu Bionic)
   Importance: Undecided
   Status: New

** Also affects: linux (Ubuntu Trusty)
   Importance: Undecided
   Status: New

** Also affects: linux (Ubuntu Xenial)
   Importance: Undecided
   Status: New

-- 
You received this bug notification because you are a member of नेपाली
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Matching subscriptions: Ubuntu 16.04 Bugs
https://bugs.launchpad.net/bugs/1774336

Title:
  FS-Cache: Assertion failed: FS-Cache: 6 == 5 is false

Status in linux package in Ubuntu:
  Confirmed
Status in linux source package in Trusty:
  New
Status in linux source package in Xenial:
  New
Status in linux source package in Artful:
  New
Status in linux source package in Bionic:
  New

Bug description:
  == SRU Justification ==

  [Impact]
  Oops during heavy NFS + FSCache use:

  [81738.886634] FS-Cache: 
  [81738.888281] FS-Cache: Assertion failed
  [81738.889461] FS-Cache: 6 == 5 is false
  [81738.890625] [ cut here ]
  [81738.891706] kernel BUG at 
/build/linux-hVVhWi/linux-4.4.0/fs/fscache/operation.c:494!

  6 == 5 represents an operation being DEAD when it was not expected to
  be.

  [Cause]
  There is a race in fscache and cachefiles. 

  One thread is in cachefiles_read_waiter:
   1) object->work_lock is taken.
   2) the operation is added to the to_do list.
   3) the work lock is dropped.
   4) fscache_enqueue_retrieval is called, which takes a reference.

  Another thread is in cachefiles_read_copier:
   1) object->work_lock is taken
   2) an item is popped off the to_do list.
   3) object->work_lock is dropped.
   4) some processing is done on the item, and fscache_put_retrieval() is 
called, dropping a reference.

  Now if the this process in cachefiles_read_copier takes place
  *between* steps 3 and 4 in cachefiles_read_waiter, a reference will be
  dropped before it is taken, which leads to the objects reference count
  hitting zero, which leads to lifecycle events for the object happening
  too soon, leading to the assertion failure later on.

  (This is simplified and clarified from the original upstream analysis
  for this patch at https://www.redhat.com/archives/linux-
  cachefs/2018-February/msg1.html and from a similar patch with a
  different approach to fixing the bug at
  https://www.redhat.com/archives/linux-cachefs/2017-June/msg2.html)

  [Fix]
  Move fscache_enqueue_retrieval under the lock in cachefiles_read_waiter. This 
means that the object cannot be popped off the to_do list until it is in a 
fully consistent state with the reference taken.

  [Testcase]
  A user has run ~100 hours of NFS stress tests and not seen this bug recur.

  [Regression Potential]
   - Limited to fscache/cachefiles. 
   - The change makes things more conservative (doing more under lock) so 
that's reassuring. 
   - There may be performance impacts but none have been observed so far.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1774336/+subscriptions

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