In practice, this requires only 2 instructions, or even only 1 for
the idmap_pg_dir size (with 4 or 64 KiB pages). Only the MAIR values
needed more than 2 instructions and it was already converted to mov_q
by 95b3f74b.
Signed-off-by: Remi Denis-Courmont <remi.denis.courmont@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>

When building allnoconfig:

arch/arm64/kernel/cpu_errata.c:174:13: warning: unused function
'call_smc_arch_workaround_1' [-Wunused-function]
static void call_smc_arch_workaround_1(void)
            ^
1 warning generated.

Follow arch/arm and mark this function as __maybe_unused.

Fixes: 4db61fef ("arm64: kvm: Modernize __smccc_workaround_1_smc_start annotations")
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Missing argument of another SYM_INNER_LABEL() breaks build for
CONFIG_FUNCTION_GRAPH_TRACER=y.

Fixes: e2d591d2 ("arm64: entry-ftrace.S: Convert to modern annotations for assembly functions")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Brown <broonie@kernel.org>

In an effort to clarify and simplify the annotation of assembly
functions new macros have been introduced. These replace ENTRY and
ENDPROC with two different annotations for normal functions and those
with unusual calling conventions. Use these for the compat VDSO,
allowing us to drop the custom ARM_ENTRY() and ARM_ENDPROC() macros.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In an effort to clarify and simplify the annotation of assembly
functions new macros have been introduced. These replace ENTRY and
ENDPROC with two different annotations for normal functions and those
with unusual calling conventions. Convert the assembly function in the
arm64 VDSO to the new macros.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In an effort to clarify and simplify the annotation of assembly
functions new macros have been introduced. These replace ENTRY and
ENDPROC with two different annotations for normal functions and those
with unusual calling conventions.

The SDEI entry points are currently annotated as normal functions but
are called from non-kernel contexts with non-standard calling convention
and should therefore be annotated as such so do so.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: James Morse <james.Morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These replace ENTRY and
ENDPROC with separate annotations for standard C callable functions,
data and code with different calling conventions.

Using these for __smccc_workaround_1_smc is more involved than for most
symbols as this symbol is annotated quite unusually, rather than just have
the explicit symbol we define _start and _end symbols which we then use to
compute the length. This does not play at all nicely with the new style
macros. Instead define a constant for the size of the function and use that
in both the C code and for .org based size checks in the assembly code.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>

We have recently introduced new macros for annotating assembly symbols
for things that aren't C functions, SYM_CODE_START() and SYM_CODE_END(),
in an effort to clarify and simplify our annotations of assembly files.

Using these for __bp_harden_hyp_vecs is more involved than for most symbols
as this symbol is annotated quite unusually as rather than just have the
explicit symbol we define _start and _end symbols which we then use to
compute the length. This does not play at all nicely with the new style
macros. Since the size of the vectors is a known constant which won't vary
the simplest thing to do is simply to drop the separate _start and _end
symbols and just use a #define for the size.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>

In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These replace ENTRY and
ENDPROC with separate annotations for standard C callable functions,
data and code with different calling conventions.  Update the more
straightforward annotations in the kvm code to the new macros.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>

In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These include specific
annotations for the start and end of data, update symbols for data to use
these.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In an effort to clarify and simplify the annotation of assembly
functions new macros have been introduced. These replace ENTRY and
ENDPROC with two different annotations for normal functions and those
with unusual calling conventions.  Neither stext nor preserve_boot_args
is called with the usual AAPCS calling conventions and they should
therefore be annotated as code.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These replace ENTRY and
ENDPROC and also add a new annotation for static functions which previously
had no ENTRY equivalent. Update the annotations in the core kernel code to
the new macros.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In an effort to clarify and simplify the annotation of assembly
functions new macros have been introduced. These replace ENTRY and
ENDPROC with two different annotations for normal functions and those
with unusual calling conventions.

return_to_handler does entertaining things with LR so doesn't follow the
usual C conventions and should therefore be annotated as code rather than
a function.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In an effort to clarify and simplify the annotation of assembly
functions new macros have been introduced. These replace ENTRY and
ENDPROC with two different annotations for normal functions and those
with unusual calling conventions.

The patchable function entry versions of ftrace_*_caller don't follow the
usual AAPCS rules, pushing things onto the stack which they don't clean up,
and therefore should be annotated as code rather than functions.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These replace ENTRY and
ENDPROC and also add a new annotation for static functions which previously
had no ENTRY equivalent. Update the annotations in the core kernel code to
the new macros.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These replace ENTRY and
ENDPROC with separate annotations for standard C callable functions,
data and code with different calling conventions.  Update the
remaining annotations in the entry.S code to the new macros.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In an effort to clarify and simplify the annotation of assembly
functions new macros have been introduced. These replace ENTRY and
ENDPROC with two different annotations for normal functions and those
with unusual calling conventions.

ret_from_fork is not a normal C function and should therefore be
annotated as code.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In an effort to clarify and simplify the annotation of assembly
functions new macros have been introduced. These replace ENTRY and
ENDPROC with two different annotations for normal functions and those
with unusual calling conventions. The vector table and handlers aren't
normal C style code so should be annotated as CODE.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Now that the rest of the code has been converted to the modern START/END
macros the AES_ENTRY() and AES_ENDPROC() macros look out of place and
like they need updating. Rename them to AES_FUNC_START() and AES_FUNC_END()
to line up with the modern style assembly macros.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

A couple of functions were missed in the modernisation of assembly macros,
update them too.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Pull btrfs fixes from David Sterba:
 "These are fixes that were found during testing with help of error
  injection, plus some other stable material.

  There's a fixup to patch added to rc1 causing locking in wrong context
  warnings, tests found one more deadlock scenario. The patches are
  tagged for stable, two of them now in the queue but we'd like all
  three released at the same time.

  I'm not happy about fixes to fixes in such a fast succession during
  rcs, but I hope we found all the fallouts of commit 28553fa9
  ('Btrfs: fix race between shrinking truncate and fiemap')"

* tag 'for-5.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix deadlock during fast fsync when logging prealloc extents beyond eof
  Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents
  btrfs: fix bytes_may_use underflow in prealloc error condtition
  btrfs: handle logged extent failure properly
  btrfs: do not check delayed items are empty for single transaction cleanup
  btrfs: reset fs_root to NULL on error in open_ctree
  btrfs: destroy qgroup extent records on transaction abort

Pull ext4 fixes from Ted Ts'o:
 "More miscellaneous ext4 bug fixes (all stable fodder)"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix mount failure with quota configured as module
  jbd2: fix ocfs2 corrupt when clearing block group bits
  ext4: fix race between writepages and enabling EXT4_EXTENTS_FL
  ext4: rename s_journal_flag_rwsem to s_writepages_rwsem
  ext4: fix potential race between s_flex_groups online resizing and access
  ext4: fix potential race between s_group_info online resizing and access
  ext4: fix potential race between online resizing and write operations
  ext4: add cond_resched() to __ext4_find_entry()
  ext4: fix a data race in EXT4_I(inode)->i_disksize

Pull csky updates from Guo Ren:
 "Sorry, I missed 5.6-rc1 merge window, but in this pull request the
  most are the fixes and the rests are between fixes and features. The
  only outside modification is the MAINTAINERS file update with our
  mailing list.

   - cache flush implementation fixes

   - ftrace modify panic fix

   - CONFIG_SMP boot problem fix

   - fix pt_regs saving for atomic.S

   - fix fixaddr_init without highmem.

   - fix stack protector support

   - fix fake Tightly-Coupled Memory code compile and use

   - fix some typos and coding convention"

* tag 'csky-for-linus-5.6-rc3' of git://github.com/c-sky/csky-linux: (23 commits)
  csky: Replace <linux/clk-provider.h> by <linux/of_clk.h>
  csky: Implement copy_thread_tls
  csky: Add PCI support
  csky: Minimize defconfig to support buildroot config.fragment
  csky: Add setup_initrd check code
  csky: Cleanup old Kconfig options
  arch/csky: fix some Kconfig typos
  csky: Fixup compile warning for three unimplemented syscalls
  csky: Remove unused cache implementation
  csky: Fixup ftrace modify panic
  csky: Add flush_icache_mm to defer flush icache all
  csky: Optimize abiv2 copy_to_user_page with VM_EXEC
  csky: Enable defer flush_dcache_page for abiv2 cpus (807/810/860)
  csky: Remove unnecessary flush_icache_* implementation
  csky: Support icache flush without specific instructions
  csky/Kconfig: Add Kconfig.platforms to support some drivers
  csky/smp: Fixup boot failed when CONFIG_SMP
  csky: Set regs->usp to kernel sp, when the exception is from kernel
  csky/mm: Fixup export invalid_pte_table symbol
  csky: Separate fixaddr_init from highmem
  ...

The C-Sky platform code is not a clock provider, and just needs to call
of_clk_init().

Hence it can include <linux/of_clk.h> instead of <linux/clk-provider.h>.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

Pull RAS fixes from Thomas Gleixner:
 "Two fixes for the AMD MCE driver:

   - Populate the per CPU MCA bank descriptor pointer only after it has
     been completely set up to prevent a use-after-free in case that one
     of the subsequent initialization step fails

   - Implement a proper release function for the sysfs entries of MCA
     threshold controls instead of freeing the memory right in the CPU
     teardown code, which leads to another use-after-free when the
     associated sysfs file is opened and accessed"

* tag 'ras-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce/amd: Fix kobject lifetime
  x86/mce/amd: Publish the bank pointer only after setup has succeeded

Pull irq fixes from Thomas Gleixner:
 "Two fixes for the irq core code which are follow ups to the recent MSI
  fixes:

   - The WARN_ON which was put into the MSI setaffinity callback for
     paranoia reasons actually triggered via a callchain which escaped
     when all the possible ways to reach that code were analyzed.

     The proc/irq/$N/*affinity interfaces have a quirk which came in
     when ALPHA moved to the generic interface: In case that the written
     affinity mask does not contain any online CPU it calls into ALPHAs
     magic auto affinity setting code.

     A few years later this mechanism was also made available to x86 for
     no good reasons and in a way which circumvents all sanity checks
     for interrupts which cannot have their affinity set from process
     context on X86 due to the way the X86 interrupt delivery works.

     It would be possible to make this work properly, but there is no
     point in doing so. If the interrupt is not yet started then the
     affinity setting has no effect and if it is started already then it
     is already assigned to an online CPU so there is no point to
     randomly move it to some other CPU. Just return EINVAL as the code
     has done before that change forever.

   - The new MSI quirk bit in the irq domain flags turned out to be
     already occupied, which escaped the author and the reviewers
     because the already in use bits were 0,6,2,3,4,5 listed in that
     order.

     That bit 6 was simply overlooked because the ordering was straight
     forward linear otherwise. So the new bit ended up being a
     duplicate.

     Fix it up by switching the oddball 6 to the obvious 1"

* tag 'irq-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/irqdomain: Make sure all irq domain flags are distinct
  genirq/proc: Reject invalid affinity masks (again)

Pull x86 fixes from Thomas Gleixner:
 "Two fixes for x86:

   - Remove the __force_oder definiton from the kaslr boot code as it is
     already defined in the page table code which makes GCC 10 builds
     fail because it changed the default to -fno-common.

   - Address the AMD erratum 1054 concerning the IRPERF capability and
     enable the Instructions Retired fixed counter on machines which are
     not affected by the erratum"

* tag 'x86-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu/amd: Enable the fixed Instructions Retired counter IRPERF
  x86/boot/compressed: Don't declare __force_order in kaslr_64.c

Pull zonefs fix from Damien Le Moal:
 "A single patch fixing typos in the documentation file"

* tag 'zonefs-5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs:
  zonefs: fix documentation typos etc.

Pull io_uring fixes from Jens Axboe:
 "Here's a small collection of fixes that were queued up:

   - Remove unnecessary NULL check (Dan)

   - Missing io_req_cancelled() call in fallocate (Pavel)

   - Put the cleanup check for aux data in the right spot (Pavel)

   - Two fixes for SQPOLL (Stefano, Xiaoguang)"

* tag 'io_uring-5.6-2020-02-22' of git://git.kernel.dk/linux-block:
  io_uring: fix __io_iopoll_check deadlock in io_sq_thread
  io_uring: prevent sq_thread from spinning when it should stop
  io_uring: fix use-after-free by io_cleanup_req()
  io_uring: remove unnecessary NULL checks
  io_uring: add missing io_req_cancelled()

Pull block fixes from Jens Axboe:
 "Just a set of NVMe fixes via Keith"

* tag 'block-5.6-2020-02-22' of git://git.kernel.dk/linux-block:
  nvme-multipath: Fix memory leak with ana_log_buf
  nvme: Fix uninitialized-variable warning
  nvme-pci: Use single IRQ vector for old Apple models
  nvme/pci: Add sleep quirk for Samsung and Toshiba drives

Pull SCSI fixes from James Bottomley:
 "Four non-core fixes.

  Two are reverts of target fixes which turned out to have unwanted side
  effects, one is a revert of an RDMA fix with the same problem and the
  final one fixes an incorrect warning about memory allocation failures
  in megaraid_sas (the driver actually reduces the allocation size until
  it succeeds)"
Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: Revert "target: iscsi: Wait for all commands to finish before freeing a session"
  scsi: Revert "RDMA/isert: Fix a recently introduced regression related to logout"
  scsi: megaraid_sas: silence a warning
  scsi: Revert "target/core: Inline transport_lun_remove_cmd()"

Merge tag 'hwmon-for-v5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:

 - Fix crash in w83627ehf driver seen with W83627DHG-P

 - Fix lockdep splat in acpi_power_meter driver

 - Fix xdpe12284 documentation Sphinx warnings

* tag 'hwmon-for-v5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (w83627ehf) Fix crash seen with W83627DHG-P
  hwmon: (acpi_power_meter) Fix lockdep splat
  Documentation/hwmon: fix xdpe12284 Sphinx warnings

Pull devicetree fixes deom Rob Herring:
 "A handful of fixes in DT bindings for MDIO bus, Allwinner CSI, OMAP
  HSMMC, and Tegra124 EMC"

* tag 'devicetree-fixes-for-5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  dt-bindings: media: csi: Fix clocks description
  dt-bindings: media: csi: Add interconnects properties
  dt-bindings: net: mdio: remove compatible string from example
  dt-bindings: memory-controller: Update example for Tegra124 EMC
  dt-bindings: mmc: omap-hsmmc: Fix SDIO interrupt

Pull s390 fixes from Vasily Gorbik:

 - Remove ieee_emulation_warnings sysctl which is a dead code.

 - Avoid triggering rebuild of the kernel during make install.

 - Enable protected virtualization guest support in default configs.

 - Fix cio_ignore seq_file .next function to increase position index.
   And use kobj_to_dev instead of container_of in cio code.

 - Fix storage block address lists to contain absolute addresses in qdio
   code.

 - Few clang warnings and spelling fixes.

* tag 's390-5.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/qdio: fill SBALEs with absolute addresses
  s390/qdio: fill SL with absolute addresses
  s390: remove obsolete ieee_emulation_warnings
  s390: make 'install' not depend on vmlinux
  s390/kaslr: Fix casts in get_random
  s390/mm: Explicitly compare PAGE_DEFAULT_KEY against zero in storage_key_init_range
  s390/pkey/zcrypt: spelling s/crytp/crypt/
  s390/cio: use kobj_to_dev() API
  s390/defconfig: enable CONFIG_PROTECTED_VIRTUALIZATION_GUEST
  s390/cio: cio_ignore_proc_seq_next should increase position index

Since commit a3a0e43f ("io_uring: don't enter poll loop if we have
CQEs pending"), if we already events pending, we won't enter poll loop.
In case SETUP_IOPOLL and SETUP_SQPOLL are both enabled, if app has
been terminated and don't reap pending events which are already in cq
ring, and there are some reqs in poll_list, io_sq_thread will enter
__io_iopoll_check(), and find pending events, then return, this loop
will never have a chance to exit.

I have seen this issue in fio stress tests, to fix this issue, let
io_sq_thread call io_iopoll_getevents() with argument 'min' being zero,
and remove __io_iopoll_check().

Fixes: a3a0e43f ("io_uring: don't enter poll loop if we have CQEs pending")
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

When CONFIG_QFMT_V2 is configured as a module, the test in
ext4_feature_set_ok() fails and so mount of filesystems with quota or
project features fails. Fix the test to use IS_ENABLED macro which
works properly even for modules.

Link: https://lore.kernel.org/r/20200221100835.9332-1-jack@suse.cz
Fixes: d65d87a0 ("ext4: improve explanation of a mount failure caused by a misconfigured kernel")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

I found a NULL pointer dereference in ocfs2_block_group_clear_bits().
The running environment:
	kernel version: 4.19
	A cluster with two nodes, 5 luns mounted on two nodes, and do some
	file operations like dd/fallocate/truncate/rm on every lun with storage
	network disconnection.

The fallocate operation on dm-23-45 caused an null pointer dereference.

The information of NULL pointer dereference as follows:
	[577992.878282] JBD2: Error -5 detected when updating journal superblock for dm-23-45.
	[577992.878290] Aborting journal on device dm-23-45.
	...
	[577992.890778] JBD2: Error -5 detected when updating journal superblock for dm-24-46.
	[577992.890908] __journal_remove_journal_head: freeing b_committed_data
	[577992.890916] (fallocate,88392,52):ocfs2_extend_trans:474 ERROR: status = -30
	[577992.890918] __journal_remove_journal_head: freeing b_committed_data
	[577992.890920] (fallocate,88392,52):ocfs2_rotate_tree_right:2500 ERROR: status = -30
	[577992.890922] __journal_remove_journal_head: freeing b_committed_data
	[577992.890924] (fallocate,88392,52):ocfs2_do_insert_extent:4382 ERROR: status = -30
	[577992.890928] (fallocate,88392,52):ocfs2_insert_extent:4842 ERROR: status = -30
	[577992.890928] __journal_remove_journal_head: freeing b_committed_data
	[577992.890930] (fallocate,88392,52):ocfs2_add_clusters_in_btree:4947 ERROR: status = -30
	[577992.890933] __journal_remove_journal_head: freeing b_committed_data
	[577992.890939] __journal_remove_journal_head: freeing b_committed_data
	[577992.890949] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
	[577992.890950] Mem abort info:
	[577992.890951]   ESR = 0x96000004
	[577992.890952]   Exception class = DABT (current EL), IL = 32 bits
	[577992.890952]   SET = 0, FnV = 0
	[577992.890953]   EA = 0, S1PTW = 0
	[577992.890954] Data abort info:
	[577992.890955]   ISV = 0, ISS = 0x00000004
	[577992.890956]   CM = 0, WnR = 0
	[577992.890958] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000f8da07a9
	[577992.890960] [0000000000000020] pgd=0000000000000000
	[577992.890964] Internal error: Oops: 96000004 [#1] SMP
	[577992.890965] Process fallocate (pid: 88392, stack limit = 0x00000000013db2fd)
	[577992.890968] CPU: 52 PID: 88392 Comm: fallocate Kdump: loaded Tainted: G        W  OE     4.19.36 #1
	[577992.890969] Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019
	[577992.890971] pstate: 60400009 (nZCv daif +PAN -UAO)
	[577992.891054] pc : _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
	[577992.891082] lr : _ocfs2_free_suballoc_bits+0x618/0x968 [ocfs2]
	[577992.891084] sp : ffff0000c8e2b810
	[577992.891085] x29: ffff0000c8e2b820 x28: 0000000000000000
	[577992.891087] x27: 00000000000006f3 x26: ffffa07957b02e70
	[577992.891089] x25: ffff807c59d50000 x24: 00000000000006f2
	[577992.891091] x23: 0000000000000001 x22: ffff807bd39abc30
	[577992.891093] x21: ffff0000811d9000 x20: ffffa07535d6a000
	[577992.891097] x19: ffff000001681638 x18: ffffffffffffffff
	[577992.891098] x17: 0000000000000000 x16: ffff000080a03df0
	[577992.891100] x15: ffff0000811d9708 x14: 203d207375746174
	[577992.891101] x13: 73203a524f525245 x12: 20373439343a6565
	[577992.891103] x11: 0000000000000038 x10: 0101010101010101
	[577992.891106] x9 : ffffa07c68a85d70 x8 : 7f7f7f7f7f7f7f7f
	[577992.891109] x7 : 0000000000000000 x6 : 0000000000000080
	[577992.891110] x5 : 0000000000000000 x4 : 0000000000000002
	[577992.891112] x3 : ffff000001713390 x2 : 2ff90f88b1c22f00
	[577992.891114] x1 : ffff807bd39abc30 x0 : 0000000000000000
	[577992.891116] Call trace:
	[577992.891139]  _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
	[577992.891162]  _ocfs2_free_clusters+0x100/0x290 [ocfs2]
	[577992.891185]  ocfs2_free_clusters+0x50/0x68 [ocfs2]
	[577992.891206]  ocfs2_add_clusters_in_btree+0x198/0x5e0 [ocfs2]
	[577992.891227]  ocfs2_add_inode_data+0x94/0xc8 [ocfs2]
	[577992.891248]  ocfs2_extend_allocation+0x1bc/0x7a8 [ocfs2]
	[577992.891269]  ocfs2_allocate_extents+0x14c/0x338 [ocfs2]
	[577992.891290]  __ocfs2_change_file_space+0x3f8/0x610 [ocfs2]
	[577992.891309]  ocfs2_fallocate+0xe4/0x128 [ocfs2]
	[577992.891316]  vfs_fallocate+0x11c/0x250
	[577992.891317]  ksys_fallocate+0x54/0x88
	[577992.891319]  __arm64_sys_fallocate+0x28/0x38
	[577992.891323]  el0_svc_common+0x78/0x130
	[577992.891325]  el0_svc_handler+0x38/0x78
	[577992.891327]  el0_svc+0x8/0xc

My analysis process as follows:
ocfs2_fallocate
  __ocfs2_change_file_space
    ocfs2_allocate_extents
      ocfs2_extend_allocation
        ocfs2_add_inode_data
          ocfs2_add_clusters_in_btree
            ocfs2_insert_extent
              ocfs2_do_insert_extent
                ocfs2_rotate_tree_right
                  ocfs2_extend_rotate_transaction
                    ocfs2_extend_trans
                      jbd2_journal_restart
                        jbd2__journal_restart
                          /* handle->h_transaction is NULL,
                           * is_handle_aborted(handle) is true
                           */
                          handle->h_transaction = NULL;
                          start_this_handle
                            return -EROFS;
            ocfs2_free_clusters
              _ocfs2_free_clusters
                _ocfs2_free_suballoc_bits
                  ocfs2_block_group_clear_bits
                    ocfs2_journal_access_gd
                      __ocfs2_journal_access
                        jbd2_journal_get_undo_access
                          /* I think jbd2_write_access_granted() will
                           * return true, because do_get_write_access()
                           * will return -EROFS.
                           */
                          if (jbd2_write_access_granted(...)) return 0;
                          do_get_write_access
                            /* handle->h_transaction is NULL, it will
                             * return -EROFS here, so do_get_write_access()
                             * was not called.
                             */
                            if (is_handle_aborted(handle)) return -EROFS;
                    /* bh2jh(group_bh) is NULL, caused NULL
                       pointer dereference */
                    undo_bg = (struct ocfs2_group_desc *)
                                bh2jh(group_bh)->b_committed_data;

If handle->h_transaction == NULL, then jbd2_write_access_granted()
does not really guarantee that journal_head will stay around,
not even speaking of its b_committed_data. The bh2jh(group_bh)
can be removed after ocfs2_journal_access_gd() and before call
"bh2jh(group_bh)->b_committed_data". So, we should move
is_handle_aborted() check from do_get_write_access() into
jbd2_journal_get_undo_access() and jbd2_journal_get_write_access()
before the call to jbd2_write_access_granted().

Link: https://lore.kernel.org/r/f72a623f-b3f1-381a-d91d-d22a1c83a336@huawei.comSigned-off-by: Yan Wang <wangyan122@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org

If EXT4_EXTENTS_FL is set on an inode while ext4_writepages() is running
on it, the following warning in ext4_add_complete_io() can be hit:

WARNING: CPU: 1 PID: 0 at fs/ext4/page-io.c:234 ext4_put_io_end_defer+0xf0/0x120

Here's a minimal reproducer (not 100% reliable) (root isn't required):

        while true; do
                sync
        done &
        while true; do
                rm -f file
                touch file
                chattr -e file
                echo X >> file
                chattr +e file
        done

The problem is that in ext4_writepages(), ext4_should_dioread_nolock()
(which only returns true on extent-based files) is checked once to set
the number of reserved journal credits, and also again later to select
the flags for ext4_map_blocks() and copy the reserved journal handle to
ext4_io_end::handle.  But if EXT4_EXTENTS_FL is being concurrently set,
the first check can see dioread_nolock disabled while the later one can
see it enabled, causing the reserved handle to unexpectedly be NULL.

Since changing EXT4_EXTENTS_FL is uncommon, and there may be other races
related to doing so as well, fix this by synchronizing changing
EXT4_EXTENTS_FL with ext4_writepages() via the existing
s_writepages_rwsem (previously called s_journal_flag_rwsem).

This was originally reported by syzbot without a reproducer at
https://syzkaller.appspot.com/bug?extid=2202a584a00fffd19fbf,
but now that dioread_nolock is the default I also started seeing this
when running syzkaller locally.

Link: https://lore.kernel.org/r/20200219183047.47417-3-ebiggers@kernel.org
Reported-by: syzbot+2202a584a00fffd19fbf@syzkaller.appspotmail.com
Fixes: 6b523df4 ("ext4: use transaction reservation for extent conversion in ext4_end_io")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org

In preparation for making s_journal_flag_rwsem synchronize
ext4_writepages() with changes to both the EXTENTS and JOURNAL_DATA
flags (rather than just JOURNAL_DATA as it does currently), rename it to
s_writepages_rwsem.

Link: https://lore.kernel.org/r/20200219183047.47417-2-ebiggers@kernel.orgSigned-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org