IPv6 checksum tests with unaligned addresses on 64-bit builds result
in unexpected failures.

Expected expected == csum_result, but
    expected == 46591 (0xb5ff)
    csum_result == 46381 (0xb52d)
with alignment offset 1

Oddly enough, the problem disappeared after adding test code into
the beginning of csum_ipv6_magic().

As it turns out, the 'sum' parameter of csum_ipv6_magic() is declared as
__wsum, which is a 32-bit variable. However, it is treated as 64-bit
variable in the 64-bit assembler code. Tests showed that the upper 32 bit
of the register used to pass the variable are _not_ cleared when entering
the function. This can result in checksum calculation errors.

Clearing the upper 32 bit of 'sum' as first operation in the assembler
code fixes the problem.
Acked-by: Helge Deller <deller@gmx.de>
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Helge Deller <deller@gmx.de>

hppa 64-bit systems calculates the IPv6 checksum using 64-bit add
operations. The last add folds protocol and length fields into the 64-bit
result. While unlikely, this operation can overflow. The overflow can be
triggered with a code sequence such as the following.

	/* try to trigger massive overflows */
	memset(tmp_buf, 0xff, sizeof(struct in6_addr));
	csum_result = csum_ipv6_magic((struct in6_addr *)tmp_buf,
				      (struct in6_addr *)tmp_buf,
				      0xffff, 0xff, 0xffffffff);

Fix the problem by adding any overflows from the final add operation into
the calculated checksum. Fortunately, we can do this without additional
cost by replacing the add operation used to fold the checksum into 32 bit
with "add,dc" to add in the missing carry.

Cc: Palmer Dabbelt <palmer@rivosinc.com>
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Helge Deller <deller@gmx.de>

Calculating the IPv6 checksum on 32-bit systems missed overflows when
adding the proto+len fields into the checksum. This results in the
following unit test failure.

    # test_csum_ipv6_magic: ASSERTION FAILED at lib/checksum_kunit.c:506
    Expected ( u64)csum_result == ( u64)expected, but
        ( u64)csum_result == 46722 (0xb682)
        ( u64)expected == 46721 (0xb681)
    not ok 5 test_csum_ipv6_magic

This is probably rarely seen in the real world because proto+len are
usually small values which will rarely result in overflows when calculating
the checksum. However, the unit test code uses large values for the length
field, causing the test to fail.

Fix the problem by adding the missing carry into the final checksum.

Cc: Palmer Dabbelt <palmer@rivosinc.com>
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Signed-off-by: Helge Deller <deller@gmx.de>

IP checksum unit tests report the following error when run on hppa/hppa64.

    # test_ip_fast_csum: ASSERTION FAILED at lib/checksum_kunit.c:463
    Expected ( u64)csum_result == ( u64)expected, but
        ( u64)csum_result == 33754 (0x83da)
        ( u64)expected == 10946 (0x2ac2)
    not ok 4 test_ip_fast_csum

0x83da is the expected result if the IP header length is 20 bytes. 0x2ac2
is the expected result if the IP header length is 24 bytes. The test fails
with an IP header length of 24 bytes. It appears that ip_fast_csum()
always returns the checksum for a 20-byte header, no matter how long
the header actually is.

Code analysis shows a suspicious assembler sequence in ip_fast_csum().

 "      addc            %0, %3, %0\n"
 "1:    ldws,ma         4(%1), %3\n"
 "      addib,<         0, %2, 1b\n"	<---

While my understanding of HPPA assembler is limited, it does not seem
to make much sense to subtract 0 from a register and to expect the result
to ever be negative. Subtracting 1 from the length parameter makes more
sense. On top of that, the operation should be repeated if and only if
the result is still > 0, so change the suspicious instruction to
 "      addib,>         -1, %2, 1b\n"

The IP checksum unit test passes after this change.

Cc: Palmer Dabbelt <palmer@rivosinc.com>
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Signed-off-by: Helge Deller <deller@gmx.de>

Use add,l to avoid clobbering the C/B bits in the PSW.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.10+

Convert to use real temp variables instead of clobbering processor
registers. This aligns the 64-bit inline assembly code with the 32-bit
assembly code which was rewritten with commit 427c1073
("parisc/unaligned: Rewrite 32-bit inline assembly of emulate_ldd()").

While at it, fix comment in 32-bit rewrite code. Temporary variables are
now used for both 32-bit and 64-bit code, so move their declarations
to the function header.

No functional change intended.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable@vger.kernel.org # v6.0+
Signed-off-by: Helge Deller <deller@gmx.de>

Since commit d492cc25 ("driver core: device.h: make struct
bus_type a const *"), the driver core can properly handle constant
struct bus_type, move the parisc_bus_type variable to be a constant
structure as well, placing it into read-only memory which can not be
modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Helge Deller <deller@gmx.de>

Starting in c23, this is a reserved keyword, so in the future, using it
will start causing build failures:

arch/parisc/math-emu/frnd.c:36:23: error: expected ';', ',' or ')' before 'nullptr'

Since I can't think of a good replacement name, add a leading underscore
to the function argument to avoid this namespace conflict. Apparently
all of these arguments are unused.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Helge Deller <deller@gmx.de>

Warn if some kernel function triggers unaligned memory accesses.
Signed-off-by: Helge Deller <deller@gmx.de>

Use irq*_rcu() functions to fix this kernel warning:

 WARNING: CPU: 0 PID: 0 at kernel/context_tracking.c:367 ct_irq_enter+0xa0/0xd0
 Modules linked in:
 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.7.0-rc3-64bit+ #1037
 Hardware name: 9000/785/C3700

 IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000412cd758 00000000412cd75c
  IIR: 03ffe01f    ISR: 0000000000000000  IOR: 0000000043c20c20
  CPU:        0   CR30: 0000000041caa000 CR31: 0000000000000000
  ORIG_R28: 0000000000000005
  IAOQ[0]: ct_irq_enter+0xa0/0xd0
  IAOQ[1]: ct_irq_enter+0xa4/0xd0
  RP(r2): irq_enter+0x34/0x68
 Backtrace:
  [<000000004034a3ec>] irq_enter+0x34/0x68
  [<000000004030dc48>] do_cpu_irq_mask+0xc0/0x450
  [<0000000040303070>] intr_return+0x0/0xc
Signed-off-by: Helge Deller <deller@gmx.de>

Pull bcachefs fixes from Kent Overstreet:
 "Some more mostly boring fixes, but some not

  User reported ones:

   - the BTREE_ITER_FILTER_SNAPSHOTS one fixes a really nasty
     performance bug; user reported an untar initially taking two
     seconds and then ~2 minutes

   - kill a __GFP_NOFAIL in the buffered read path; this was a leftover
     from the trickier fix to kill __GFP_NOFAIL in readahead, where we
     can't return errors (and have to silently truncate the read
     ourselves).

     bcachefs can't use GFP_NOFAIL for folio state unlike iomap based
     filesystems because our folio state is just barely too big, 2MB
     hugepages cause us to exceed the 2 page threshhold for GFP_NOFAIL.

     additionally, the flags argument was just buggy, we weren't
     supplying GFP_KERNEL previously (!)"

* tag 'bcachefs-2024-02-25' of https://evilpiepirate.org/git/bcachefs:
  bcachefs: fix bch2_save_backtrace()
  bcachefs: Fix check_snapshot() memcpy
  bcachefs: Fix bch2_journal_flush_device_pins()
  bcachefs: fix iov_iter count underflow on sub-block dio read
  bcachefs: Fix BTREE_ITER_FILTER_SNAPSHOTS on inodes btree
  bcachefs: Kill __GFP_NOFAIL in buffered read path
  bcachefs: fix backpointer_to_text() when dev does not exist

Missed a call in the previous fix.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Pull two documentation build fixes from Jonathan Corbet:

 - The XFS online fsck documentation uses incredibly deeply nested
   subsection and list nesting; that broke the PDF docs build. Tweak a
   parameter to tell LaTeX to allow the deeper nesting.

 - Fix a 6.8 PDF-build regression

* tag 'docs-6.8-fixes3' of git://git.lwn.net/linux:
  docs: translations: use attribute to store current language
  docs: Instruct LaTeX to cope with deeper nesting

Pull USB fixes from Greg KH:
 "Here are some small USB fixes for 6.8-rc6 to resolve some reported
  problems. These include:

   - regression fixes with typec tpcm code as reported by many

   - cdnsp and cdns3 driver fixes

   - usb role setting code bugfixes

   - build fix for uhci driver

   - ncm gadget driver bugfix

   - MAINTAINERS entry update

  All of these have been in linux-next all week with no reported issues
  and there is at least one fix in here that is in Thorsten's regression
  list that is being tracked"

* tag 'usb-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: typec: tpcm: Fix issues with power being removed during reset
  MAINTAINERS: Drop myself as maintainer of TYPEC port controller drivers
  usb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs
  Revert "usb: typec: tcpm: reset counter when enter into unattached state after try role"
  usb: gadget: omap_udc: fix USB gadget regression on Palm TE
  usb: dwc3: gadget: Don't disconnect if not started
  usb: cdns3: fix memory double free when handle zero packet
  usb: cdns3: fixed memory use after free at cdns3_gadget_ep_disable()
  usb: roles: don't get/set_role() when usb_role_switch is unregistered
  usb: roles: fix NULL pointer issue when put module's reference
  usb: cdnsp: fixed issue with incorrect detecting CDNSP family controllers
  usb: cdnsp: blocked some cdns3 specific code
  usb: uhci-grlib: Explicitly include linux/platform_device.h

Pull tty/serial driver fixes from Greg KH:
 "Here are three small serial/tty driver fixes for 6.8-rc6 that resolve
  the following reported errors:

   - riscv hvc console driver fix that was reported by many

   - amba-pl011 serial driver fix for RS485 mode

   - stm32 serial driver fix for RS485 mode

  All of these have been in linux-next all week with no reported
  problems"

* tag 'tty-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: amba-pl011: Fix DMA transmission in RS485 mode
  serial: stm32: do not always set SER_RS485_RX_DURING_TX if RS485 is enabled
  tty: hvc: Don't enable the RISC-V SBI console by default

Pull x86 fixes from Borislav Petkov:

 - Make sure clearing CPU buffers using VERW happens at the latest
   possible point in the return-to-userspace path, otherwise memory
   accesses after the VERW execution could cause data to land in CPU
   buffers again

* tag 'x86_urgent_for_v6.8_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  KVM/VMX: Move VERW closer to VMentry for MDS mitigation
  KVM/VMX: Use BT+JNC, i.e. EFLAGS.CF to select VMRESUME vs. VMLAUNCH
  x86/bugs: Use ALTERNATIVE() instead of mds_user_clear static key
  x86/entry_32: Add VERW just before userspace transition
  x86/entry_64: Add VERW just before userspace transition
  x86/bugs: Add asm helpers for executing VERW

Pull irq fixes from Borislav Petkov:

 - Make sure GICv4 always gets initialized to prevent a kexec-ed kernel
   from silently failing to set it up

 - Do not call bus_get_dev_root() for the mbigen irqchip as it always
   returns NULL - use NULL directly

 - Fix hardware interrupt number truncation when assigning MSI
   interrupts

 - Correct sending end-of-interrupt messages to disabled interrupts
   lines on RISC-V PLIC

* tag 'irq_urgent_for_v6.8_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3-its: Do not assume vPE tables are preallocated
  irqchip/mbigen: Don't use bus_get_dev_root() to find the parent
  PCI/MSI: Prevent MSI hardware interrupt number truncation
  irqchip/sifive-plic: Enable interrupt if needed before EOI

Pull erofs fix from Gao Xiang:

 - Fix page refcount leak when looking up specific inodes
   introduced by metabuf reworking

* tag 'erofs-for-6.8-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: fix refcount on the metabuf used for inode lookup

Pull RCU pathwalk fixes from Al Viro:
 "We still have some races in filesystem methods when exposed to RCU
  pathwalk. This series is a result of code audit (the second round of
  it) and it should deal with most of that stuff.

  Still pending: ntfs3 ->d_hash()/->d_compare() and ceph_d_revalidate().
  Up to maintainers (a note for NTFS folks - when documentation says
  that a method may not block, it *does* imply that blocking allocations
  are to be avoided. Really)"

[ More explanations for people who aren't familiar with the vagaries of
  RCU path walking: most of it is hidden from filesystems, but if a
  filesystem actively participates in the low-level path walking it
  needs to make sure the fields involved in that walk are RCU-safe.

  That "actively participate in low-level path walking" includes things
  like having its own ->d_hash()/->d_compare() routines, or by having
  its own directory permission function that doesn't just use the common
  helpers.  Having a ->d_revalidate() function will also have this issue.

  Note that instead of making everything RCU safe you can also choose to
  abort the RCU pathwalk if your operation cannot be done safely under
  RCU, but that obviously comes with a performance penalty. One common
  pattern is to allow the simple cases under RCU, and abort only if you
  need to do something more complicated.

  So not everything needs to be RCU-safe, and things like the inode etc
  that the VFS itself maintains obviously already are. But these fixes
  tend to be about properly RCU-delaying things like ->s_fs_info that
  are maintained by the filesystem and that got potentially released too
  early.   - Linus ]

* tag 'pull-fixes.pathwalk-rcu-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ext4_get_link(): fix breakage in RCU mode
  cifs_get_link(): bail out in unsafe case
  fuse: fix UAF in rcu pathwalks
  procfs: make freeing proc_fs_info rcu-delayed
  procfs: move dropping pde and pid from ->evict_inode() to ->free_inode()
  nfs: fix UAF on pathwalk running into umount
  nfs: make nfs_set_verifier() safe for use in RCU pathwalk
  afs: fix __afs_break_callback() / afs_drop_open_mmap() race
  hfsplus: switch to rcu-delayed unloading of nls and freeing ->s_fs_info
  exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helper
  affs: free affs_sb_info with kfree_rcu()
  rcu pathwalk: prevent bogus hard errors from may_lookup()
  fs/super.c: don't drop ->s_user_ns until we free struct super_block itself

Pull vfs fixes from Al Viro:
 "A couple of fixes - revert of regression from this cycle and a fix for
  erofs failure exit breakage (had been there since way back)"

* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  erofs: fix handling kern_mount() failure
  Revert "get rid of DCACHE_GENOCIDE"

1) errors from ext4_getblk() should not be propagated to caller
unless we are really sure that we would've gotten the same error
in non-RCU pathwalk.
2) we leak buffer_heads if ext4_getblk() is successful, but bh is
not uptodate.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

->d_revalidate() bails out there, anyway.  It's not enough
to prevent getting into ->get_link() in RCU mode, but that
could happen only in a very contrieved setup.  Not worth
trying to do anything fancy here unless ->d_revalidate()
stops kicking out of RCU mode at least in some cases.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

->permission(), ->get_link() and ->inode_get_acl() might dereference
->s_fs_info (and, in case of ->permission(), ->s_fs_info->fc->user_ns
as well) when called from rcu pathwalk.

Freeing ->s_fs_info->fc is rcu-delayed; we need to make freeing ->s_fs_info
and dropping ->user_ns rcu-delayed too.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

makes proc_pid_ns() safe from rcu pathwalk (put_pid_ns()
is still synchronous, but that's not a problem - it does
rcu-delay everything that needs to be)
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

that keeps both around until struct inode is freed, making access
to them safe from rcu-pathwalk
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

NFS ->d_revalidate(), ->permission() and ->get_link() need to access
some parts of nfs_server when called in RCU mode:
	server->flags
	server->caps
	*(server->io_stats)
and, worst of all, call
	server->nfs_client->rpc_ops->have_delegation
(the last one - as NFS_PROTO(inode)->have_delegation()).  We really
don't want to RCU-delay the entire nfs_free_server() (it would have
to be done with schedule_work() from RCU callback, since it can't
be made to run from interrupt context), but actual freeing of
nfs_server and ->io_stats can be done via call_rcu() just fine.
nfs_client part is handled simply by making nfs_free_client() use
kfree_rcu().
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

nfs_set_verifier() relies upon dentry being pinned; if that's
the case, grabbing ->d_lock stabilizes ->d_parent and guarantees
that ->d_parent points to a positive dentry.  For something
we'd run into in RCU mode that is *not* true - dentry might've
been through dentry_kill() just as we grabbed ->d_lock, with
its parent going through the same just as we get to into
nfs_set_verifier_locked().  It might get to detaching inode
(and zeroing ->d_inode) before nfs_set_verifier_locked() gets
to fetching that; we get an oops as the result.

That can happen in nfs{,4} ->d_revalidate(); the call chain in
question is nfs_set_verifier_locked() <- nfs_set_verifier() <-
nfs_lookup_revalidate_delegated() <- nfs{,4}_do_lookup_revalidate().
We have checked that the parent had been positive, but that's
done before we get to nfs_set_verifier() and it's possible for
memory pressure to pick our dentry as eviction candidate by that
time.  If that happens, back-to-back attempts to kill dentry and
its parent are quite normal.  Sure, in case of eviction we'll
fail the ->d_seq check in the caller, but we need to survive
until we return there...
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

In __afs_break_callback() we might check ->cb_nr_mmap and if it's non-zero
do queue_work(&vnode->cb_work).  In afs_drop_open_mmap() we decrement
->cb_nr_mmap and do flush_work(&vnode->cb_work) if it reaches zero.

The trouble is, there's nothing to prevent __afs_break_callback() from
seeing ->cb_nr_mmap before the decrement and do queue_work() after both
the decrement and flush_work().  If that happens, we might be in trouble -
vnode might get freed before the queued work runs.

__afs_break_callback() is always done under ->cb_lock, so let's make
sure that ->cb_nr_mmap can change from non-zero to zero while holding
->cb_lock (the spinlock component of it - it's a seqlock and we don't
need to mess with the counter).
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

->d_hash() and ->d_compare() use those, so we need to delay freeing
them.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

That stuff can be accessed by ->d_hash()/->d_compare(); as it is, we have
a hard-to-hit UAF if rcu pathwalk manages to get into ->d_hash() on a filesystem
that is in process of getting shut down.

Besides, having nls and upcase table cleanup moved from ->put_super() towards
the place where sbi is freed makes for simpler failure exits.
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

one of the flags in it is used by ->d_hash()/->d_compare()
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

If lazy call of ->permission() returns a hard error, check that
try_to_unlazy() succeeds before returning it.  That both makes
life easier for ->permission() instances and closes the race
in ENOTDIR handling - it is possible that positive d_can_lookup()
seen in link_path_walk() applies to the state *after* unlink() +
mkdir(), while nd->inode matches the state prior to that.

Normally seeing e.g. EACCES from permission check in rcu pathwalk
means that with some timings non-rcu pathwalk would've run into
the same; however, running into a non-executable regular file
in the middle of a pathname would not get to permission check -
it would fail with ENOTDIR instead.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Avoids fun races in RCU pathwalk...  Same goes for freeing LSM shite
hanging off super_block's arse.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

check_snapshot() copies the bch_snapshot to a temporary to easily handle
older versions that don't have all the fields of the current version,
but it lacked a min() to correctly handle keys newer and larger than the
current version.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

If a journal write errored, the list of devices it was written to could
be empty - we're not supposed to mark an empty replicas list.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

bch2_direct_IO_read() checks the request offset and size for sector
alignment and then falls through to a couple calculations to shrink
the size of the request based on the inode size. The problem is that
these checks round up to the fs block size, which runs the risk of
underflowing iter->count if the block size happens to be large
enough. This is triggered by fstest generic/361 with a 4k block
size, which subsequently leads to a crash. To avoid this crash,
check that the shorten length doesn't exceed the overall length of
the iter.

Fixes:
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Su Yue <glass.su@suse.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

If we're in FILTER_SNAPSHOTS mode and we start scanning a range of the
keyspace where no keys are visible in the current snapshot, we have a
problem - we'll scan for a very long time before scanning terminates.

Awhile back, this was fixed for most cases with peek_upto() (and
assertions that enforce that it's being used).

But the fix missed the fact that the inodes btree is different - every
key offset is in a different snapshot tree, not just the inode field.

Fixes:
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Recently, we fixed our __GFP_NOFAIL usage in the readahead path, but the
easy one in read_single_folio() (where wa can return an error) was
missed - oops.

Fixes:
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Fixes:
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>