CONFIG_COMPAT_VDSO is defined by passing '-DCONFIG_COMPAT_VDSO' to the
compiler when the generic compat vDSO code is in use. It's much cleaner
and simpler to expose this as a proper Kconfig option (like x86 does),
so do that and remove the bodge.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
For consistency with CROSS_COMPILE_COMPAT, mechanically rename COMPATCC
to CC_COMPAT so that specifying aspects of the compat vDSO toolchain in
the environment isn't needlessly confusing.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Directly passing the '--target' option to clang by appending to
COMPATCC does not work if COMPATCC has been specified explicitly as
an argument to Make unless the 'override' directive is used, which is
ugly and different to what is done in the top-level Makefile.
Move the '--target' option for clang out of COMPATCC and into
VDSO_CAFLAGS, where it will be picked up when compiling and assembling
the 32-bit vDSO under clang.
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
KBUILD_CPPFLAGS is defined differently depending on whether the main
compiler is clang or not. This means that it is not possible to build
the compat vDSO with GCC if the rest of the kernel is built with clang.
Define VDSO_CPPFLAGS directly to break this dependency and allow a clang
kernel to build a compat vDSO with GCC:
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- \
CROSS_COMPILE_COMPAT=arm-linux-gnueabihf- CC=clang \
COMPATCC=arm-linux-gnueabihf-gcc
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
There's no need to export COMPATCC, so just define it locally in the
vdso32/Makefile, which is the only place where it is used.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Rather than force the use of GCC for the compat cross-compiler, instead
extract the target from CROSS_COMPILE_COMPAT and pass it to clang if the
main compiler is clang.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
What we thought would be the module clock is actually the clock meant to be
used by the sensors, and play no role in the CSI controller. Now that the
binding has been updated to reflect that, let's update the device tree too.
Fixes: d2b9c64443 ("ARM: dts: sun7i: Add CSI0 controller")
Reported-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
It turns out that what was thought to be the module clock was actually the
clock meant to be used by the sensor, and isn't playing any role with the
CSI controller itself. Let's drop that clock from our binding.
Fixes: c5e8f4ccd7 ("media: dt-bindings: media: Add Allwinner A10 CSI binding")
Reported-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
There are two checks to see if the manual gpio is configured, but
these the check is seeing if the structure is NULL instead it
should check to see if there are CTS and/or RTS pins defined.
This patch uses checks for those individual pins instead of
checking for the structure itself to restore auto RTS/CTS.
Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Yegor Yefremov <yegorslists@googlemail.com>
Link: https://lore.kernel.org/r/20191006163314.23191-2-aford173@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Patch fixes issue with Halt Endnpoint Test observed during using g_zero
driver as DUT. Bug occurred only on some testing board.
Endpoint can defer transition to Halted state if endpoint has pending
requests.
Patch add additional condition that allows to return correct endpoint
status during Get Endpoint Status request even if the halting endpoint
is in progress.
Reported-by: Rahul Kumar <kurahul@cadence.com>
Signed-off-by: Rahul Kumar <kurahul@cadence.com>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Fixes: 7733f6c32e ("usb: cdns3: Add Cadence USB3 DRD Driver")
Tested-by: Roger Quadros <rogerq@ti.com>
Link: https://lore.kernel.org/r/1570430355-26118-1-git-send-email-pawell@cadence.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64 was the last architecture using CROSS_COMPILE_COMPAT_VDSO config
option. With this patch series the dependency in the architecture has
been removed.
Remove CROSS_COMPILE_COMPAT_VDSO from the Unified vDSO library code.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Older versions of binutils (prior to 2.24) do not support the "ISHLD"
option for memory barrier instructions, which leads to a build failure
when assembling the vdso32 library.
Add a compilation time mechanism that detects if binutils supports those
instructions and configure the kernel accordingly.
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
The .config file and the generated include/config/auto.conf can
end up out of sync after a set of commands since
CONFIG_CROSS_COMPILE_COMPAT_VDSO is not updated correctly.
The sequence can be reproduced as follows:
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig
[...]
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig
[set CONFIG_CROSS_COMPILE_COMPAT_VDSO="arm-linux-gnueabihf-"]
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-
Which results in:
arch/arm64/Makefile:62: CROSS_COMPILE_COMPAT not defined or empty,
the compat vDSO will not be built
even though the compat vDSO has been built:
$ file arch/arm64/kernel/vdso32/vdso.so
arch/arm64/kernel/vdso32/vdso.so: ELF 32-bit LSB pie executable, ARM,
EABI5 version 1 (SYSV), dynamically linked,
BuildID[sha1]=c67f6c786f2d2d6f86c71f708595594aa25247f6, stripped
A similar case that involves changing the configuration parameter
multiple times can be reconducted to the same family of problems.
Remove the use of CONFIG_CROSS_COMPILE_COMPAT_VDSO altogether and
instead rely on the cross-compiler prefix coming from the environment
via CROSS_COMPILE_COMPAT, much like we do for the rest of the kernel.
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
When detecting a spurious EL1 translation fault, we attempt to compare
ESR_EL1.DFSC with PAR_EL1.FST. We erroneously use FIELD_PREP() to
extract PAR_EL1.FST, when we should be using FIELD_GET().
In the wise words of Robin Murphy:
| FIELD_GET() is a UBFX, FIELD_PREP() is a BFI
Using FIELD_PREP() means that that dfsc & ESR_ELx_FSC_TYPE is always
zero, and hence not equal to ESR_ELx_FSC_FAULT. Thus we detect any
unhandled translation fault as spurious.
... so let's use FIELD_GET() to ensure we don't decide all translation
faults are spurious. ESR_EL1.DFSC occupies bits [5:0], and requires no
shifting.
Fixes: 42f91093b0 ("arm64: mm: Ignore spurious translation faults taken from the kernel")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Robin Murphy <robin.murphy@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Fix the cleanup of the crypto state on a call after the call has been
disconnected. As the call has been disconnected, its connection ref has
been discarded and so we can't go through that to get to the security ops
table.
Fix this by caching the security ops pointer in the rxrpc_call struct and
using that when freeing the call security state. Also use this in other
places we're dealing with call-specific security.
The symptoms look like:
BUG: KASAN: use-after-free in rxrpc_release_call+0xb2d/0xb60
net/rxrpc/call_object.c:481
Read of size 8 at addr ffff888062ffeb50 by task syz-executor.5/4764
Fixes: 1db88c5343 ("rxrpc: Fix -Wframe-larger-than= warnings from on-stack crypto")
Reported-by: syzbot+eed305768ece6682bb7f@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
The rxrpc_peer record needs to hold a reference on the rxrpc_local record
it points as the peer is used as a base to access information in the
rxrpc_local record.
This can cause problems in __rxrpc_put_peer(), where we need the network
namespace pointer, and in rxrpc_send_keepalive(), where we need to access
the UDP socket, leading to symptoms like:
BUG: KASAN: use-after-free in __rxrpc_put_peer net/rxrpc/peer_object.c:411
[inline]
BUG: KASAN: use-after-free in rxrpc_put_peer+0x685/0x6a0
net/rxrpc/peer_object.c:435
Read of size 8 at addr ffff888097ec0058 by task syz-executor823/24216
Fix this by taking a ref on the local record for the peer record.
Fixes: ace45bec6d ("rxrpc: Fix firewall route keepalive")
Fixes: 2baec2c3f8 ("rxrpc: Support network namespacing")
Reported-by: syzbot+b9be979c55f2bea8ed30@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
rxrpc_put_call() calls trace_rxrpc_call() after it has done the decrement
of the refcount - which looks at the debug_id in the call record. But
unless the refcount was reduced to zero, we no longer have the right to
look in the record and, indeed, it may be deleted by some other thread.
Fix this by getting the debug_id out before decrementing the refcount and
then passing that into the tracepoint.
Fixes: e34d4234b0 ("rxrpc: Trace rxrpc_call usage")
Signed-off-by: David Howells <dhowells@redhat.com>
rxrpc_put_*conn() calls trace_rxrpc_conn() after they have done the
decrement of the refcount - which looks at the debug_id in the connection
record. But unless the refcount was reduced to zero, we no longer have the
right to look in the record and, indeed, it may be deleted by some other
thread.
Fix this by getting the debug_id out before decrementing the refcount and
then passing that into the tracepoint.
Fixes: 363deeab6d ("rxrpc: Add connection tracepoint and client conn state tracepoint")
Signed-off-by: David Howells <dhowells@redhat.com>
rxrpc_put_peer() calls trace_rxrpc_peer() after it has done the decrement
of the refcount - which looks at the debug_id in the peer record. But
unless the refcount was reduced to zero, we no longer have the right to
look in the record and, indeed, it may be deleted by some other thread.
Fix this by getting the debug_id out before decrementing the refcount and
then passing that into the tracepoint.
This can cause the following symptoms:
BUG: KASAN: use-after-free in __rxrpc_put_peer net/rxrpc/peer_object.c:411
[inline]
BUG: KASAN: use-after-free in rxrpc_put_peer+0x685/0x6a0
net/rxrpc/peer_object.c:435
Read of size 8 at addr ffff888097ec0058 by task syz-executor823/24216
Fixes: 1159d4b496 ("rxrpc: Add a tracepoint to track rxrpc_peer refcounting")
Reported-by: syzbot+b9be979c55f2bea8ed30@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
$id doesn't match the actual filename, so update the $id
Fixes: c5e8f4ccd7 ("media: dt-bindings: media: Add Allwinner A10 CSI binding")
Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
When sendmsg() finds a call to continue on with, if the call is in an
inappropriate state, it doesn't release the ref it just got on that call
before returning an error.
This causes the following symptom to show up with kasan:
BUG: KASAN: use-after-free in rxrpc_send_keepalive+0x8a2/0x940
net/rxrpc/output.c:635
Read of size 8 at addr ffff888064219698 by task kworker/0:3/11077
where line 635 is:
whdr.epoch = htonl(peer->local->rxnet->epoch);
The local endpoint (which cannot be pinned by the call) has been released,
but not the peer (which is pinned by the call).
Fix this by releasing the call in the error path.
Fixes: 37411cad63 ("rxrpc: Fix potential NULL-pointer exception")
Reported-by: syzbot+d850c266e3df14da1d31@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Commit 7e534323c4 ("mtd: rawnand: Pass a nand_chip object to
chip->read_xxx() hooks") modified the prototype of the struct nand_chip
read_buf function pointer. In the au1550nd driver we have 2
implementations of read_buf. The previously mentioned commit modified
the au_read_buf() implementation to match the function pointer, but not
au_read_buf16(). This results in a compiler warning for MIPS
db1xxx_defconfig builds:
drivers/mtd/nand/raw/au1550nd.c:443:57:
warning: pointer type mismatch in conditional expression
Fix this by updating the prototype of au_read_buf16() to take a struct
nand_chip pointer as its first argument, as is expected after commit
7e534323c4 ("mtd: rawnand: Pass a nand_chip object to chip->read_xxx()
hooks").
Note that this shouldn't have caused any functional issues at runtime,
since the offset of the struct mtd_info within struct nand_chip is 0
making mtd_to_nand() effectively a type-cast.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: 7e534323c4 ("mtd: rawnand: Pass a nand_chip object to chip->read_xxx() hooks")
Cc: stable@vger.kernel.org # v4.20+
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Currently if the client identifies problems when processing
metadata returned in CREATE response, the open handle is being
leaked. This causes multiple problems like a file missing a lease
break by that client which causes high latencies to other clients
accessing the file. Another side-effect of this is that the file
can't be deleted.
Fix this by closing the file after the client hits an error after
the file was opened and the open descriptor wasn't returned to
the user space. Also convert -ESTALE to -EOPENSTALE to allow
the VFS to revalidate a dentry and retry the open.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
After 'Initial git repository build' commit,
'mapping_table_ERRHRD' variable has not been used.
So 'mapping_table_ERRHRD' const variable could be removed
to mute below warning message:
fs/cifs/netmisc.c:120:40: warning: unused variable 'mapping_table_ERRHRD' [-Wunused-const-variable]
static const struct smb_to_posix_error mapping_table_ERRHRD[] = {
^
Signed-off-by: Austin Kim <austindh.kim@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Now that sparse has been fixed, it spotted a couple recent minor
endian errors (and removed one additional sparse warning).
Thanks to Luc Van Oostenryck for his help fixing sparse.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Headphone on XPS 9350/9360 produces a background white noise. The The
noise level somehow correlates with "Headphone Mic Boost", when it sets
to 1 the noise disappears. However, doing this has a side effect, which
also decreases the overall headphone volume so I didn't send the patch
upstream.
The noise was bearable back then, but after commit 717f43d81a ("ALSA:
hda/realtek - Update headset mode for ALC256") the noise exacerbates to
a point it starts hurting ears.
So let's use the workaround to set "Headphone Mic Boost" to 1 and lock
it so it's not touchable by userspace.
Fixes: 717f43d81a ("ALSA: hda/realtek - Update headset mode for ALC256")
BugLink: https://bugs.launchpad.net/bugs/1654448
BugLink: https://bugs.launchpad.net/bugs/1845810
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20191003043919.10960-1-kai.heng.feng@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
While writing the tests for copy_struct_from_user(), I used a construct
that Linus doesn't appear to be too fond of:
On 2019-10-04, Linus Torvalds <torvalds@linux-foundation.org> wrote:
> Hmm. That code is ugly, both before and after the fix.
>
> This just doesn't make sense for so many reasons:
>
> if ((ret |= test(umem_src == NULL, "kmalloc failed")))
>
> where the insanity comes from
>
> - why "|=" when you know that "ret" was zero before (and it had to
> be, for the test to make sense)
>
> - why do this as a single line anyway?
>
> - don't do the stupid "double parenthesis" to hide a warning. Make it
> use an actual comparison if you add a layer of parentheses.
So instead, use a bog-standard check that isn't nearly as ugly.
Fixes: 341115822f ("usercopy: Add parentheses around assignment in test_copy_struct_from_user")
Fixes: f5a1a536fa ("lib: introduce copy_struct_from_user() helper")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20191005233028.18566-1-cyphar@cyphar.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Guarantee zeroed memory buffers for cases where potential memory
leak to disk can occur. In these cases, kmem_alloc is used and
doesn't zero the buffer, opening the possibility of information
leakage to disk.
Use existing infrastucture (xfs_buf_allocate_memory) to obtain
the already zeroed buffer from kernel memory.
This solution avoids the performance issue that would occur if a
wholesale change to replace kmem_alloc with kmem_zalloc was done.
Signed-off-by: Bill O'Donnell <billodo@redhat.com>
[darrick: fix bitwise complaint about kmflag_mask]
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The flags arg is always passed as zero, so remove it.
(xfs_buf_get_uncached takes flags to support XBF_NO_IOACCT for
the sb, but that should never be relevant for xfs_get_aghdr_buf)
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
To ensure that all blocks touched by the range [offset, offset + count)
are allocated, we need to calculate the block count from the difference
of the range end (rounded up) and the range start (rounded down).
Before this patch, we just round up the byte count, which may lead to
unaligned ranges not being fully allocated:
$ touch test_file
$ block_size=$(stat -fc '%S' test_file)
$ fallocate -o $((block_size / 2)) -l $block_size test_file
$ xfs_bmap test_file
test_file:
0: [0..7]: 1396264..1396271
1: [8..15]: hole
There should not be a hole there. Instead, the first two blocks should
be fully allocated.
With this patch applied, the result is something like this:
$ touch test_file
$ block_size=$(stat -fc '%S' test_file)
$ fallocate -o $((block_size / 2)) -l $block_size test_file
$ xfs_bmap test_file
test_file:
0: [0..15]: 11024..11039
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
In commit 4ed2863951 ("fs, elf: drop MAP_FIXED usage from elf_map") we
changed elf to use MAP_FIXED_NOREPLACE instead of MAP_FIXED for the
executable mappings.
Then, people reported that it broke some binaries that had overlapping
segments from the same file, and commit ad55eac74f ("elf: enforce
MAP_FIXED on overlaying elf segments") re-instated MAP_FIXED for some
overlaying elf segment cases. But only some - despite the summary line
of that commit, it only did it when it also does a temporary brk vma for
one obvious overlapping case.
Now Russell King reports another overlapping case with old 32-bit x86
binaries, which doesn't trigger that limited case. End result: we had
better just drop MAP_FIXED_NOREPLACE entirely, and go back to MAP_FIXED.
Yes, it's a sign of old binaries generated with old tool-chains, but we
do pride ourselves on not breaking existing setups.
This still leaves MAP_FIXED_NOREPLACE in place for the load_elf_interp()
and the old load_elf_library() use-cases, because nobody has reported
breakage for those. Yet.
Note that in all the cases seen so far, the overlapping elf sections
seem to be just re-mapping of the same executable with different section
attributes. We could possibly introduce a new MAP_FIXED_NOFILECHANGE
flag or similar, which acts like NOREPLACE, but allows just remapping
the same executable file using different protection flags.
It's not clear that would make a huge difference to anything, but if
people really hate that "elf remaps over previous maps" behavior, maybe
at least a more limited form of remapping would alleviate some concerns.
Alternatively, we should take a look at our elf_map() logic to see if we
end up not mapping things properly the first time.
In the meantime, this is the minimal "don't do that then" patch while
people hopefully think about it more.
Reported-by: Russell King <linux@armlinux.org.uk>
Fixes: 4ed2863951 ("fs, elf: drop MAP_FIXED usage from elf_map")
Fixes: ad55eac74f ("elf: enforce MAP_FIXED on overlaying elf segments")
Cc: Michal Hocko <mhocko@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull dma-mapping regression fix from Christoph Hellwig:
"Revert an incorret hunk from a patch that caused problems on various
arm boards (Andrey Smirnov)"
* tag 'dma-mapping-5.4-1' of git://git.infradead.org/users/hch/dma-mapping:
dma-mapping: fix false positive warnings in dma_common_free_remap()
Jose Abreu says:
====================
net: stmmac: Fixes for -net
Fixes for -net. More info in commit logs.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
With the current MAC addresses hard-coded in the test we can get some
false positives as we use the Hash Filtering method. Let's change the
MAC addresses in the tests to be unique when hashed.
Fixes: 091810dbde ("net: stmmac: Introduce selftests support")
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some setups may not have all Unicast addresses filters available. Check
the number of available filters before trying to setup it.
Fixes: 477286b53f ("stmmac: add GMAC4 core support")
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to check if the number of available Hash Filters is enough to
run the test, otherwise we will get false failures.
Fixes: 091810dbde ("net: stmmac: Introduce selftests support")
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
scale_up wakes up waiters after scaling up. But after scaling max, it
should not wake up more waiters as waiters will not have anything to
do. This patch fixes this by making scale_up (and also scale_down)
return when threshold is reached.
This bug causes increased fdatasync latency when fdatasync and dd
conv=sync are performed in parallel on 4.19 compared to 4.14. This
bug was introduced during refactoring of blk-wbt code.
Fixes: a79050434b ("blk-rq-qos: refactor out common elements of blk-wbt")
Cc: stable@vger.kernel.org
Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
