The code cleaning transaction's lists of checkpoint buffers has a bug
where it increases bh refcount only after releasing
journal->j_list_lock. Thus the following race is possible:

CPU0					CPU1
jbd2_log_do_checkpoint()
					jbd2_journal_try_to_free_buffers()
					  __journal_try_to_free_buffer(bh)
  ...
  while (transaction->t_checkpoint_io_list)
  ...
    if (buffer_locked(bh)) {

<-- IO completes now, buffer gets unlocked -->

      spin_unlock(&journal->j_list_lock);
					    spin_lock(&journal->j_list_lock);
					    __jbd2_journal_remove_checkpoint(jh);
					    spin_unlock(&journal->j_list_lock);
					  try_to_free_buffers(page);
      get_bh(bh) <-- accesses freed bh

Fix the problem by grabbing bh reference before unlocking
journal->j_list_lock.

Fixes: dc6e8d66 ("jbd2: don't call get_bh() before calling __jbd2_journal_remove_checkpoint()")
Fixes: be1158cc ("jbd2: fold __process_buffer() into jbd2_log_do_checkpoint()")
Reported-by: syzbot+7f4a27091759e2fe7453@syzkaller.appspotmail.com
CC: stable@vger.kernel.org
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

We return most failure of dquota_initialize() except
inode evict, this could make a bit sense, for example
we allow file removal even quota files are broken?

But it dosen't make sense to allow setting project
if quota files etc are broken.
Signed-off-by: Wang Shilong <wshilong@ddn.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

Currently, project quota could be changed by fssetxattr
ioctl, and existed permission check inode_owner_or_capable()
is obviously not enough, just think that common users could
change project id of file, that could make users to
break project quota easily.

This patch try to follow same regular of xfs project
quota:

"Project Quota ID state is only allowed to change from
within the init namespace. Enforce that restriction only
if we are trying to change the quota ID state.
Everything else is allowed in user namespaces."

Besides that, check and set project id'state should
be an atomic operation, protect whole operation with
inode lock, ext4_ioctl_setproject() is only used for
ioctl EXT4_IOC_FSSETXATTR, we have held mnt_want_write_file()
before ext4_ioctl_setflags(), and ext4_ioctl_setproject()
is called after ext4_ioctl_setflags(), we could share
codes, so remove it inside ext4_ioctl_setproject().
Signed-off-by: Wang Shilong <wshilong@ddn.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Cc: stable@kernel.org

The tables in the ext4 readme are not particularly space efficient in
the text or html outputs, and they're totally broken in the pdf output.
Convert them into titled paragraphs so that they render more nicely.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

It turns out that the latex table formatters lay out table columns with
the exact proportional widths given in the table metadata, even if text
overflows outside the box.  This was not caught during the initial
import because the HTML renderers are smart enough to fudge the table.

Fix the table column width formatting problems in the data structures
and algorithms documentation so that we don't have squashed columns.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

The documentation build scripts won't build a pdf for the ext4
documentation unless explicitly called for, so ask for a separate
ext4.pdf to be generated with all the documentation.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Return type of ext4_page_mkwrite and ext4_filemap_fault are
changed to use vm_fault_t type.

With this patch all the callers of block_page_mkwrite_return()
are changed to handle vm_fault_t. So converting the return type
of block_page_mkwrite_return() to vm_fault_t.
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Matthew Wilcox <willy@infradead.org>

Variable retries is not initialized in ext4_da_write_inline_data_begin()
which can lead to nondeterministic number of retries in case we hit
ENOSPC. Initialize retries to zero as we do everywhere else.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Fixes: bc0ca9df ("ext4: retry allocation when inline->extent conversion failed")
Cc: stable@kernel.org

The code EXT4_IOC_SWAP_BOOT ioctl hasn't been updated in a while, and
it's a bit broken with respect to more modern ext4 kernels, especially
metadata checksums.

Other problems fixed with this commit:

* Don't allow installing a DAX, swap file, or an encrypted file as a
  boot loader.

* Respect the immutable and append-only flags.

* Wait until any DIO operations are finished *before* calling
  truncate_inode_pages().

* Don't swap inode->i_flags, since these flags have nothing to do with
  the inode blocks --- and it will give the IMA/audit code heartburn
  when the inode is evicted.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Reported-by: syzbot+e81ccd4744c6c4f71354@syzkaller.appspotmail.com

Enabling DX_DEBUG triggers the build error below.  info is an attribute
of  the dxroot structure.

linux/fs/ext4/namei.c:2264:12: error: ‘info’
undeclared (first use in this function); did you mean ‘insl’?
	   	  info->indirect_levels));

Fixes: e08ac99f ("ext4: add largedir feature")
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>

If the starting block number of either the source or destination file
exceeds the EOF, EXT4_IOC_MOVE_EXT should return EINVAL.

Also fixed the helper function mext_check_coverage() so that if the
logical block is beyond EOF, make it return immediately, instead of
looping until the block number wraps all the away around.  This takes
long enough that if there are multiple threads trying to do pound on
an the same inode doing non-sensical things, it can end up triggering
the kernel's soft lockup detector.

Reported-by: syzbot+c61979f6f2cba5cb3c06@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

Add new code to count canceled pending cluster reservations on bigalloc
file systems and to reduce the cluster reservation count on all file
systems using delayed allocation.  This replaces old code in
ext4_da_page_release_reservations that was incorrect.
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Modify ext4_ext_remove_space() and the code it calls to correct the
reserved cluster count for pending reservations (delayed allocated
clusters shared with allocated blocks) when a block range is removed
from the extent tree.  Pending reservations may be found for the clusters
at the ends of written or unwritten extents when a block range is removed.
If a physical cluster at the end of an extent is freed, it's necessary
to increment the reserved cluster count to maintain correct accounting
if the corresponding logical cluster is shared with at least one
delayed and unwritten extent as found in the extents status tree.

Add a new function, ext4_rereserve_cluster(), to reapply a reservation
on a delayed allocated cluster sharing blocks with a freed allocated
cluster.  To avoid ENOSPC on reservation, a flag is applied to
ext4_free_blocks() to briefly defer updating the freeclusters counter
when an allocated cluster is freed.  This prevents another thread
from allocating the freed block before the reservation can be reapplied.

Redefine the partial cluster object as a struct to carry more state
information and to clarify the code using it.

Adjust the conditional code structure in ext4_ext_remove_space to
reduce the indentation level in the main body of the code to improve
readability.
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Ext4 does not always reduce the reserved cluster count by the number
of clusters allocated when mapping a delayed extent.  It sometimes
adds back one or more clusters after allocation if delalloc blocks
adjacent to the range allocated by ext4_ext_map_blocks() share the
clusters newly allocated for that range.  However, this overcounts
the number of clusters needed to satisfy future mapping requests
(holding one or more reservations for clusters that have already been
allocated) and premature ENOSPC and quota failures, etc., result.

Ext4 also does not reduce the reserved cluster count when allocating
clusters for non-delayed allocated writes that have previously been
reserved for delayed writes.  This also results in overcounts.

To make it possible to handle reserved cluster accounting for
fallocated regions in the same manner as used for other non-delayed
writes, do the reserved cluster accounting for them at the time of
allocation.  In the current code, this is only done later when a
delayed extent sharing the fallocated region is finally mapped.

Address comment correcting handling of unsigned long long constant
from Jan Kara's review of RFC version of this patch.
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

The code in ext4_da_map_blocks sometimes reserves space for more
delayed allocated clusters than it should, resulting in premature
ENOSPC, exceeded quota, and inaccurate free space reporting.

Fix this by checking for written and unwritten blocks shared in the
same cluster with the newly delayed allocated block.  A cluster
reservation should not be made for a cluster for which physical space
has already been allocated.
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Add new pending reservation mechanism to help manage reserved cluster
accounting.  Its primary function is to avoid the need to read extents
from the disk when invalidating pages as a result of a truncate, punch
hole, or collapse range operation.
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Ext4 contains a few functions that are used to search for delayed
extents or blocks in the extents status tree.  Rather than duplicate
code to add new functions to search for extents with different status
values, such as written or a combination of delayed and unwritten,
generalize the existing code to search for caller-specified extents
status values.  Also, move this code into extents_status.c where it
is better associated with the data structures it operates upon, and
where it can be more readily used to implement new extents status tree
functions that might want a broader scope for i_es_lock.

Three missing static specifiers in RFC version of patch reported and
fixed by Fengguang Wu <fengguang.wu@intel.com>.
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Miguel writes:
  "A trivial fix for auxdisplay

    - MAINTAINERS reference fix for moved file
      Reported by Joe Perches"

* tag 'auxdisplay-for-greg-v4.19-rc6' of https://github.com/ojeda/linux:
  MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c

Merge tag 'libnvdimm-fixes2-4.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Dan writes:
  "filesystem-dax for 4.19-rc6

   Fix a deadlock in the new for 4.19 dax_lock_mapping_entry() routine."

* tag 'libnvdimm-fixes2-4.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: Fix deadlock in dax_lock_mapping_entry()

Commit 51c1e9b5 ("auxdisplay: Move panel.c to drivers/auxdisplay folder")
moved the file, but the MAINTAINERS reference was not updated.

Link: https://lore.kernel.org/lkml/20180928220131.31075-1-joe@perches.com/Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>

Jens writes:
  "Block fixes for 4.19-rc6

   A set of fixes that should go into this release. This pull request
   contains:

   - A fix (hopefully) for the persistent grants for xen-blkfront. A
     previous fix from this series wasn't complete, hence reverted, and
     this one should hopefully be it. (Boris Ostrovsky)

   - Fix for an elevator drain warning with SMR devices, which is
     triggered when you switch schedulers (Damien)

   - bcache deadlock fix (Guoju Fang)

   - Fix for the block unplug tracepoint, which has had the
     timer/explicit flag reverted since 4.11 (Ilya)

   - Fix a regression in this series where the blk-mq timeout hook is
     invoked with the RCU read lock held, hence preventing it from
     blocking (Keith)

   - NVMe pull from Christoph, with a single multipath fix (Susobhan Dey)"

* tag 'for-linus-20180929' of git://git.kernel.dk/linux-block:
  xen/blkfront: correct purging of persistent grants
  Revert "xen/blkfront: When purging persistent grants, keep them in the buffer"
  blk-mq: I/O and timer unplugs are inverted in blktrace
  bcache: add separate workqueue for journal_write to avoid deadlock
  xen/blkfront: When purging persistent grants, keep them in the buffer
  block: fix deadline elevator drain for zoned block devices
  blk-mq: Allow blocking queue tag iter callbacks
  nvme: properly propagate errors in nvme_mpath_init

Thomas writes:
  "A single fix for the AMD memory encryption boot code so it does not
   read random garbage instead of the cached encryption bit when a kexec
   kernel is allocated above the 32bit address limit."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Fix kexec booting failure in the SEV bit detection code

Thomas writes:
  "Three small fixes for clocksource drivers:
   - Proper error handling in the Atmel PIT driver
   - Add CLOCK_SOURCE_SUSPEND_NONSTOP for TI SoCs so suspend works again
   - Fix the next event function for Facebook Backpack-CMM BMC chips so
     usleep(100) doesnt sleep several milliseconds"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/timer-atmel-pit: Properly handle error cases
  clocksource/drivers/fttmr010: Fix set_next_event handler
  clocksource/drivers/ti-32k: Add CLOCK_SOURCE_SUSPEND_NONSTOP flag for non-am43 SoCs

Thomas writes:
  "A single fix for a missing sanity check when a pinned event is tried
  to be read on the wrong CPU due to a legit event scheduling failure."

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Add sanity check to deal with pinned event failure

Rafael writes:
  "Power management fix for 4.19-rc6

   Fix incorrect __init and __exit annotations in the Qualcomm
   Kryo cpufreq driver (Nathan Chancellor)."

* tag 'pm-4.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: qcom-kryo: Fix section annotations

There is currently a warning when building the Kryo cpufreq driver into
the kernel image:

WARNING: vmlinux.o(.text+0x8aa424): Section mismatch in reference from
the function qcom_cpufreq_kryo_probe() to the function
.init.text:qcom_cpufreq_kryo_get_msm_id()
The function qcom_cpufreq_kryo_probe() references
the function __init qcom_cpufreq_kryo_get_msm_id().
This is often because qcom_cpufreq_kryo_probe lacks a __init
annotation or the annotation of qcom_cpufreq_kryo_get_msm_id is wrong.

Remove the '__init' annotation from qcom_cpufreq_kryo_get_msm_id
so that there is no more mismatch warning.

Additionally, Nick noticed that the remove function was marked as
'__init' when it should really be marked as '__exit'.

Fixes: 46e2856b (cpufreq: Add Kryo CPU scaling driver)
Fixes: 5ad7346b (cpufreq: kryo: Add module remove and exit)
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.18+ <stable@vger.kernel.org> # 4.18+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Christoph writes:
  "dma mapping fix for 4.19-rc6

   fix a missing Kconfig symbol for commits introduced in 4.19-rc"

* tag 'dma-mapping-4.19-3' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: add the missing ARCH_HAS_SYNC_DMA_FOR_CPU_ALL declaration

Dmitry writes:
  "Input updates for v4.19-rc5

   Just a few driver fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: uinput - allow for max == min during input_absinfo validation
  Input: elantech - enable middle button of touchpad on ThinkPad P72
  Input: atakbd - fix Atari CapsLock behaviour
  Input: atakbd - fix Atari keymap
  Input: egalax_ts - add system wakeup support
  Input: gpio-keys - fix a documentation index issue

Mark writes:
  "spi: Fixes for v4.19

   Quite a few fixes for the Renesas drivers in here, plus a fix for the
   Tegra driver and some documentation fixes for the recently added
   spi-mem code.  The Tegra fix is relatively large but fairly
   straightforward and mechanical, it runs on probe so it's been
   reasonably well covered in -next testing."

* tag 'spi-fix-v4.19-rc5' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: spi-mem: Move the DMA-able constraint doc to the kerneldoc header
  spi: spi-mem: Add missing description for data.nbytes field
  spi: rspi: Fix interrupted DMA transfers
  spi: rspi: Fix invalid SPI use during system suspend
  spi: sh-msiof: Fix handling of write value for SISTR register
  spi: sh-msiof: Fix invalid SPI use during system suspend
  spi: gpio: Fix copy-and-paste error
  spi: tegra20-slink: explicitly enable/disable clock

Merge tag 'regulator-v4.19-rc5' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Mark writes:
  "regulator: Fixes for 4.19

   A collection of fairly minor bug fixes here, a couple of driver
   specific ones plus two core fixes.  There's one fix for the new
   suspend state code which fixes some confusion with constant values
   that are supposed to indicate noop operation and another fixing a
   race condition with the creation of sysfs files on new regulators."

* tag 'regulator-v4.19-rc5' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: fix crash caused by null driver data
  regulator: Fix 'do-nothing' value for regulators without suspend state
  regulator: da9063: fix DT probing with constraints
  regulator: bd71837: Disable voltage monitoring for LDO3/4

Michael writes:
  "powerpc fixes for 4.19 #3

   A reasonably big batch of fixes due to me being away for a few weeks.

   A fix for the TM emulation support on Power9, which could result in
   corrupting the guest r11 when running under KVM.

   Two fixes to the TM code which could lead to userspace GPR corruption
   if we take an SLB miss at exactly the wrong time.

   Our dynamic patching code had a bug that meant we could patch freed
   __init text, which could lead to corrupting userspace memory.

   csum_ipv6_magic() didn't work on little endian platforms since we
   optimised it recently.

   A fix for an endian bug when reading a device tree property telling
   us how many storage keys the machine has available.

   Fix a crash seen on some configurations of PowerVM when migrating the
   partition from one machine to another.

   A fix for a regression in the setup of our CPU to NUMA node mapping
   in KVM guests.

   A fix to our selftest Makefiles to make them work since a recent
   change to the shared Makefile logic."

* tag 'powerpc-4.19-3' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  selftests/powerpc: Fix Makefiles for headers_install change
  powerpc/numa: Use associativity if VPHN hcall is successful
  powerpc/tm: Avoid possible userspace r1 corruption on reclaim
  powerpc/tm: Fix userspace r13 corruption
  powerpc/pseries: Fix unitialized timer reset on migration
  powerpc/pkeys: Fix reading of ibm, processor-storage-keys property
  powerpc: fix csum_ipv6_magic() on little endian platforms
  powerpc/powernv/ioda2: Reduce upper limit for DMA window size (again)
  powerpc: Avoid code patching freed init sections
  KVM: PPC: Book3S HV: Fix guest r11 corruption with POWER9 TM workarounds

Linus writes:
  "Pin control fixes for v4.19:
   - Fixes to x86 hardware:
   - AMD interrupt debounce issues
   - Faulty Intel cannonlake register offset
   - Revert pin translation IRQ locking"

* tag 'pinctrl-v4.19-4' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  Revert "pinctrl: intel: Do pin translation when lock IRQ"
  pinctrl: cannonlake: Fix HOSTSW_OWN register offset of H variant
  pinctrl/amd: poll InterruptEnable bits in amd_gpio_irq_set_type

It is possible that a failure can occur during the scheduling of a
pinned event. The initial portion of perf_event_read_local() contains
the various error checks an event should pass before it can be
considered valid. Ensure that the potential scheduling failure
of a pinned event is checked for and have a credible error.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: acme@kernel.org
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/6486385d1f30336e9973b24c8c65f5079543d3d3.1537377064.git.reinette.chatre@intel.com

Dave writes:
  "drm fixes for 4.19-rc6

   Looks like a pretty normal week for graphics,

   core: syncobj fix, panel link regression revert
   amd: suspend/resume fixes, EDID emulation fix
   mali-dp: NV12 writeback and vblank reset fixes
   etnaviv: DMA setup fix"

* tag 'drm-fixes-2018-09-28' of git://anongit.freedesktop.org/drm/drm:
  drm/amd/display: Fix Edid emulation for linux
  drm/amd/display: Fix Vega10 lightup on S3 resume
  drm/amdgpu: Fix vce work queue was not cancelled when suspend
  Revert "drm/panel: Add device_link from panel device to DRM device"
  drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set
  drm/malidp: Fix writeback in NV12
  drm: mali-dp: Call drm_crtc_vblank_reset on device init
  drm/etnaviv: add DMA configuration for etnaviv platform device

Merge tag 'riscv-for-linus-4.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Palmer writes:
  "A Single RISC-V Update for 4.19-rc6

   The Debian guys have been pushing on our port and found some
   unversioned symbols leaking into modules.  This PR contains a single
   fix for that issue."

* tag 'riscv-for-linus-4.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux:
  RISC-V: include linux/ftrace.h in asm-prototypes.h

Bjorn writes:
  "PCI fixes:

  - Fix ACPI hotplug issue that causes black screen crash at boot (Mika
    Westerberg)

  - Fix DesignWare "scheduling while atomic" issues (Jisheng Zhang)

  - Add PPC contacts to MAINTAINERS for PCI core error handling (Bjorn
    Helgaas)

  - Sort Mobiveil MAINTAINERS entry (Lorenzo Pieralisi)"

* tag 'pci-v4.19-fixes-2' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge
  PCI: dwc: Fix scheduling while atomic issues
  MAINTAINERS: Move mobiveil PCI driver entry where it belongs
  MAINTAINERS: Update PPC contacts for PCI core error handling

Pull NVMe fix from Christoph.

* 'nvme-4.19' of git://git.infradead.org/nvme:
  nvme: properly propagate errors in nvme_mpath_init

Commit a46b5367 ("xen/blkfront: cleanup
stale persistent grants") introduced a regression as purged persistent
grants were not pu into the list of free grants again. Correct that.
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Fix didn't work for all cases, reverting to add a (hopefully)
better fix.

This reverts commit f151ba98.
Signed-off-by: Jens Axboe <axboe@kernel.dk>