13 Jan, 2021
6 commits
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Memory hotplugging is allowed only for multiples of section sizes.
Section size could be huge (ex. 1GB for arm64 targets) thus limiting
to add/remove lower chunks of memory. This patch allows drivers to add
memory of subsection sizes which are then added to memblock. This does
not create a separate memblock device nodes for newly added subsections
until the whole of the memblock section is added.Bug: 170460867
Change-Id: I15749b5320340cba4d526e7ddb26a9cd6029c690
Signed-off-by: Sudarshan Rajagopalan -
There are out of tree drivers which need IOMMU_SYS_CACHE_ONLY
to be able to cache their data buffers in the system cache,
so restore it.Bug: 176778547
Change-Id: Ic632a6f5951f9917e6006088b065fdbaf4e1b374
Signed-off-by: Isaac J. Manjarres -
After certain memory blocks are offlined, some usecases require that the
page-table mappings are removed while still keeping the memblock device nodes,
memory resources and the memmap entries intact. This is to avoid the overhead
involved in using 'remove_memory' if the offlined blocks will be added/onlined
back into the system at later point. {populate/depopulate}_range_driver_managed
provide the abilty to drivers to tear-down and create page-table mappings of
memory blocks that its managing, without having to use 'remove_memory' and
friends for the purpose.
These functions does not interfere with mappings of boot memory or resources
that isn't owned by the driver.Bug: 171907330
Change-Id: Ie11201334bd7438bf87f933ccc81814fa99162c4
Signed-off-by: Sudarshan Rajagopalan -
The vendor hook in select_task_rq_fair() currently sees a potentially
stale task utilization. Make sure to sync it beforehand to avoid any
issues.Fixes: a1fc1fba460b ("ANDROID: sched: add restrict vendor hook to modify task placement policy in EAS")
Signed-off-by: Quentin Perret
Change-Id: I7675ce9fd37b160f8a7ba9651ae73b69a16d6d12 -
The vendor hook in find_energy_efficient_cpu() currently sees a
potentially stale task utilization. Make sure to sync it beforehand to
avoid any issues by moving the call at the top of the function. This
also ensures the check on task_fits_capacity() when the sync flag is set
sees an up-to-date task util.Fixes: a9c5fcfe9c76 ("ANDROID: sched/fair: Have sync honor fits_capacity")
Fixes: 147a9b3d9eab ("ANDROID: sched: Add vendor hooks for find_energy_efficient_cpu")
Signed-off-by: Quentin Perret
Change-Id: Ie9a6c89249a2aefbccced4786ce4d4728e39dd12 -
Enable the KUNIT core, which has a small ABI impact, and also the
DEBUGFS feature so that results can be reaped. This change does not
actually enable any KUNIT tests or the internal selftests, those must be
enabled by downstream builds.Bug: 176228452
Change-Id: I2817cb1495fe7bf0485e63f877a68b1971e26cc5
Signed-off-by: Alistair Delva
12 Jan, 2021
6 commits
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Add support for IOMMU drivers to have their own map_sg() callbacks.
This completes the path for having iommu_map_sg() invoke an IOMMU
driver's map_sg() callback, which can then invoke the io-pgtable
map_sg() callback with the entire scatter-gather list, so that it
can be processed entirely in the io-pgtable layer.For IOMMU drivers that do not provide a callback, the default
implementation of iterating through the scatter-gather list, while
calling iommu_map() will be used.Bug: 176779203
Link: https://lore.kernel.org/linux-iommu/1610376862-927-1-git-send-email-isaacm@codeaurora.org/T/#t
Change-Id: I3d5a8a9e8648649d8dcdda3fa1df41d72f87a528
Signed-off-by: Isaac J. Manjarres
Tested-by: Sai Prakash Ranjan -
While mapping a scatter-gather list, iommu_map_sg() calls
into the IOMMU driver through an indirect call, which can
call into the io-pgtable code through another indirect call.This sequence of going through the IOMMU core code, the IOMMU
driver, and finally the io-pgtable code, occurs for every
element in the scatter-gather list, in the worse case, which
is not optimal.Introduce a map_sg callback in the io-pgtable ops so that
IOMMU drivers can invoke it with the complete scatter-gather
list, so that it can be processed within the io-pgtable
code entirely, reducing the number of indirect calls, and
boosting overall iommu_map_sg() performance.Bug: 176779203
Link: https://lore.kernel.org/linux-iommu/1610376862-927-1-git-send-email-isaacm@codeaurora.org/T/#t
Change-Id: I4b2088dd08eb97dcd94a6c6968082a3c4395351a
Signed-off-by: Isaac J. Manjarres
Tested-by: Sai Prakash Ranjan -
UFS specficication allows different VCC configurations for UFS devices,
for example:(1). 2.70V - 3.60V (Activated by default in UFS core driver)
(2). 1.70V - 1.95V (Activated if "vcc-supply-1p8" is declared in
device tree)
(3). 2.40V - 2.70V (Supported since UFS 3.x)With the introduction of UFS 3.x products, an issue is happening that UFS
driver will use wrong "min_uV-max_uV" values to configure the voltage of
VCC regulator on UFU 3.x products with the configuration (3) used.To solve this issue, we simply remove pre-defined initial VCC voltage
values in UFS core driver with below reasons,1. UFS specifications do not define how to detect the VCC configuration
supported by attached device.2. Device tree already supports standard regulator properties.
Therefore VCC voltage shall be defined correctly in device tree, and shall
not changed by UFS driver. What UFS driver needs to do is simply enable or
disable the VCC regulator only.Similar change is applied to VCCQ and VCCQ2 as well.
Note that we keep struct ufs_vreg unchanged. This allows vendors to
configure proper min_uV and max_uV of any regulators to make
regulator_set_voltage() works during regulator toggling flow in the
future. Without specific vendor configurations, min_uV and max_uV will be
NULL by default and UFS core driver will enable or disable the regulator
only without adjusting its voltage.Bug: 176226589
(cherry picked from commit 5b44a07b6bb2c26905b16deb479e9ba4e5605e97
git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git 5.11/scsi-queue)
Link: https://lore.kernel.org/r/20201202091819.22363-1-stanley.chu@mediatek.com
Reviewed-by: Asutosh Das
Reviewed-by: Bjorn Andersson
Reviewed-by: Can Guo
Acked-by: Avri Altman
Signed-off-by: Stanley Chu
Signed-off-by: Martin K. PetersenSigned-off-by: Bao D. Nguyen
Signed-off-by: Paul Lawrence
Change-Id: Icb9c24d50cd8b6fff9f21748773686271d5dbd7b -
Export pcpu_nr_pages symbol which is used as part
of meminfo collection from minidump module.Bug: 177027175
Change-Id: I08262ec95a3f1be8322b9b8d2d9c4098518fc408
Signed-off-by: Vijayanand Jitta -
Enable TRACE_MMIO_ACCESS config for memory mapped io
register read and write tracing support in GKI image.Bug: 169045115
Change-Id: I27d115092789303a4c8f0c99d9bcb887ef3cc163
Signed-off-by: Prasad Sodagudi -
Add register read/write operations tracing support.
ftrace events helps to trace register read and write
location details of memory mapped IO registers.
These trace logs helps to debug un clocked access
of peripherals.Bug: 169045115
Change-Id: I849bf75b84c24c8f3e9d2e8fba34a10ddcf4aaca
Signed-off-by: Prasad Sodagudi
11 Jan, 2021
2 commits
-
Export total_swapcache_pages symbol which is used
as part of meminfo collection from minidump module.Bug: 176277894
Change-Id: I75f508555b7f310c1aee788a7e300862abccba93
Signed-off-by: Vijayanand Jitta -
Export si_swapinfo symbol which is used as part
of meminfo collection from minidump module.Bug: 176277894
Change-Id: I5dc1672ce649c22dc33d4a544ee5a38f8376becf
Signed-off-by: Vijayanand Jitta
10 Jan, 2021
1 commit
-
Changes in 5.10.5
net/sched: sch_taprio: reset child qdiscs before freeing them
mptcp: fix security context on server socket
ethtool: fix error paths in ethnl_set_channels()
ethtool: fix string set id check
md/raid10: initialize r10_bio->read_slot before use.
drm/amd/display: Add get_dig_frontend implementation for DCEx
io_uring: close a small race gap for files cancel
jffs2: Allow setting rp_size to zero during remounting
jffs2: Fix NULL pointer dereference in rp_size fs option parsing
spi: dw-bt1: Fix undefined devm_mux_control_get symbol
opp: fix memory leak in _allocate_opp_table
opp: Call the missing clk_put() on error
scsi: block: Fix a race in the runtime power management code
mm/hugetlb: fix deadlock in hugetlb_cow error path
mm: memmap defer init doesn't work as expected
lib/zlib: fix inflating zlib streams on s390
io_uring: don't assume mm is constant across submits
io_uring: use bottom half safe lock for fixed file data
io_uring: add a helper for setting a ref node
io_uring: fix io_sqe_files_unregister() hangs
uapi: move constants from to
tools headers UAPI: Sync linux/const.h with the kernel headers
cgroup: Fix memory leak when parsing multiple source parameters
zlib: move EXPORT_SYMBOL() and MODULE_LICENSE() out of dfltcc_syms.c
scsi: cxgb4i: Fix TLS dependency
Bluetooth: hci_h5: close serdev device and free hu in h5_close
fbcon: Disable accelerated scrolling
reiserfs: add check for an invalid ih_entry_count
misc: vmw_vmci: fix kernel info-leak by initializing dbells in vmci_ctx_get_chkpt_doorbells()
media: gp8psk: initialize stats at power control logic
f2fs: fix shift-out-of-bounds in sanity_check_raw_super()
ALSA: seq: Use bool for snd_seq_queue internal flags
ALSA: rawmidi: Access runtime->avail always in spinlock
bfs: don't use WARNING: string when it's just info.
ext4: check for invalid block size early when mounting a file system
fcntl: Fix potential deadlock in send_sig{io, urg}()
io_uring: check kthread stopped flag when sq thread is unparked
rtc: sun6i: Fix memleak in sun6i_rtc_clk_init
module: set MODULE_STATE_GOING state when a module fails to load
quota: Don't overflow quota file offsets
rtc: pl031: fix resource leak in pl031_probe
powerpc: sysdev: add missing iounmap() on error in mpic_msgr_probe()
i3c master: fix missing destroy_workqueue() on error in i3c_master_register
NFSv4: Fix a pNFS layout related use-after-free race when freeing the inode
f2fs: avoid race condition for shrinker count
f2fs: fix race of pending_pages in decompression
module: delay kobject uevent until after module init call
powerpc/64: irq replay remove decrementer overflow check
fs/namespace.c: WARN if mnt_count has become negative
watchdog: rti-wdt: fix reference leak in rti_wdt_probe
um: random: Register random as hwrng-core device
um: ubd: Submit all data segments atomically
NFSv4.2: Don't error when exiting early on a READ_PLUS buffer overflow
ceph: fix inode refcount leak when ceph_fill_inode on non-I_NEW inode fails
drm/amd/display: updated wm table for Renoir
tick/sched: Remove bogus boot "safety" check
s390: always clear kernel stack backchain before calling functions
io_uring: remove racy overflow list fast checks
ALSA: pcm: Clear the full allocated memory at hw_params
dm verity: skip verity work if I/O error when system is shutting down
ext4: avoid s_mb_prefetch to be zero in individual scenarios
device-dax: Fix range release
Linux 5.10.5Signed-off-by: Greg Kroah-Hartman
Change-Id: I2b481bfac06bafdef2cf3cc1ac2c2a4ddf9913dc
09 Jan, 2021
3 commits
-
CONFIG_MEMCG introduces overhead both in terms of memory usage as well
as in the minor page fault path and after moving to PSI it is currently
unused on non-Android Go devices. Disable it in GKI to avoid the overhead.Bug: 169443770
Bug: 172296409
Signed-off-by: Suren Baghdasaryan
Change-Id: I717c2a1bde6264285b86d583ae1a1007c36be223 -
Only kill a task with a negative ADJ score if there are no tasks with
non-negative ADJ scores. Otherwise, kill the task with the most
badness points whose ADJ score is also positive, if such a suitable
task exists.Bug: 173837271
Signed-off-by: Chris Goldsworthy
Change-Id: I70fe48a3eeb853085bb1acfb422f88cd36d1f14d -
"flags" is added to the vendor hook parameter so that the module can know
the event type of task enqueue/dequeue.Bug: 176917922
Signed-off-by: Park Bumgyu
Change-Id: I7cc60908e301d75393bdf84861878a94de80d683
08 Jan, 2021
10 commits
-
Add export symbol resched_curr to enable scheduler value add.
Bug: 176077958
Change-Id: I9c26b4d8738d6fd7d1067cb164a30b0228c5a301
Signed-off-by: Shaleen Agrawal -
Add vendors hooks for to facilitate various scheduler value adds.
Bug: 176077958
Change-Id: I5d488ae78ce05f81e6c73b69c56128b065647fec
Signed-off-by: Shaleen Agrawal -
Handling all combinations of the VMAP_STACK and SHADOW_CALL_STACK options
in sdei_arch_get_entry_point() makes the code difficult to read,
particularly when considering the error and cleanup paths.Move the checking of these options into the callee functions, so that
they return early if the relevant option is not enabled.Bug: 169781940
Change-Id: I3daf8a409d3544fa4e76a28c2b2ae9efb82001ba
(cherry picked from commit eec3bf6861a8703ab63992578b1776353c5ac2a1)
Signed-off-by: Will Deacon
Signed-off-by: Sami Tolvanen -
Use scs_alloc() to allocate also IRQ and SDEI shadow stacks instead of
using statically allocated stacks.Bug: 169781940
Change-Id: If3f38d603a7c1e8ebcf1e8655b70fa6bfde7c48d
(cherry picked from commit ac20ffbb0279aae7be48567fb734eae7d050769e)
Signed-off-by: Sami Tolvanen
Acked-by: Will Deacon
Link: https://lore.kernel.org/r/20201130233442.2562064-3-samitolvanen@google.com
[will: Move CONFIG_SHADOW_CALL_STACK check into init_irq_scs()]
Signed-off-by: Will Deacon -
The kernel currently uses kmem_cache to allocate shadow call stacks,
which means an overflows may not be immediately detected and can
potentially result in another task's shadow stack to be overwritten.This change switches SCS to use virtually mapped shadow stacks for
tasks, which increases shadow stack size to a full page and provides
more robust overflow detection, similarly to VMAP_STACK.Bug: 169781940
Change-Id: I92c8f5706c11e4bf45b071e4f302a65502faa1e1
(cherry picked from commit a2abe7cbd8fe2db5ff386c968e2273d9dc6c468d)
Signed-off-by: Sami Tolvanen
Acked-by: Will Deacon
Link: https://lore.kernel.org/r/20201130233442.2562064-2-samitolvanen@google.com
Signed-off-by: Will Deacon -
At present, EAS gets disabled when on ASYM Capacity systems
if all BIG or Little CPUs gets hot-plugged. Instead of disabling
EAS by default, add trace hook and let vendor decide if EAS should
be disabled or not.Bug: 176964092
Change-Id: I583272cc89d44f3e3a4b1c43e3f75d731092ebf6
Signed-off-by: Satya Durga Srinivasu Prabhala -
A task can migrate either while it is waking or while it
is running via load balancer. Print the task status
i.e running or not in sched_migrate_task. This helps in
counting the different types of migrations without relying
on other trace events.Bug: 176709810
Change-Id: Ib473f9ccdc78003bb1f5d2dc24354f2db7a684f5
Signed-off-by: Pavankumar Kondeti
Signed-off-by: Satya Durga Srinivasu Prabhala -
When the sum of the utilization of CPUs in a power domain is zero,
return the energy as 0 without doing any computations.Acked-by: Quentin Perret
Reviewed-by: Dietmar Eggemann
Signed-off-by: Pavankumar Kondeti
Signed-off-by: Rafael J. Wysocki(cherry picked from commit 9cc7e96aa846f9086431d6c2d33ff9ab42d72b2d)
Bug: 173981595
Signed-off-by: Pavankumar Kondeti
Change-Id: I9b1a83d210c30a8a86da26f94ac0c2f855d2ed10 -
Temporary workaround to enable arm64 gki devices to boot.
Virtual devices failed to boot with 5.10 ARM64 GKI because symbol
stripping has removed tracepoint symbols pertaining to xdp which are
included in the symbol allowlist.klog excerpt for this error.
init: Loading module /lib/modules/virtio_net.ko with args ""
virtio_net: disagrees about version of symbol __traceiter_xdp_exception
virtio_net: Unknown symbol __traceiter_xdp_exception (err -22)
virtio_net: disagrees about version of symbol __tracepoint_xdp_exception
virtio_net: Unknown symbol __tracepoint_xdp_exception (err -22)
init: Failed to insmod '/lib/modules/virtio_net.ko' with args ''
init: LoadWithAliases was unable to load virtio_net
init: Failed to load kernel modulesBug: 176831960
Test: Treehugger
Signed-off-by: Ram Muthiah
Change-Id: If5b6fd12ce1c783966ff4ed0a8bc141d077c71a3 -
To enable bfq i/o group scheduling for separating i/o groups to
foreground and background i/o groups, we need to set CONFIG_IOSCHED_BFQ
and CONFIG_BFQ_GROUP_IOSCHED to "y".Bug: 171739280
Bug: 172520400
Signed-off-by: Daeho Jeong
Change-Id: If9b5664ecfc8f78d9792d7ee5d3ea5a88a50b9d7
07 Jan, 2021
9 commits
-
Add vendor hook tracepoints to track when cpu util gets
updated and when freq is choosen.Bug: 174488007
Signed-off-by: Saravana Kannan
Signed-off-by: Rohit Gupta
Signed-off-by: Jonathan Avila
Signed-off-by: Jimmy Shiu
Change-Id: Ibb22fd0337a2539820a05b1e6b54b09aeaebd040
Signed-off-by: Will McVicker -
Collect the time for each allocation recorded in page owner so that
allocation "surges" can be measured.Record the pid for each allocation recorded in page owner so that the
source of allocation "surges" can be better identified.The above is very useful when doing memory analysis. On a crash for
example, we can get this information from kdump (or ramdump) and parse it
to figure out memory allocation problems.Please note that on x86_64 this increases the size of struct page_owner
from 16 bytes to 32.Vlastimil: it's not a functionality intended for production, so unless
somebody says they need to enable page_owner for debugging and this
increase prevents them from fitting into available memory, let's not
complicate things with making this optional.[lmark@codeaurora.org: v3]
Link: https://lkml.kernel.org/r/20201210160357.27779-1-georgi.djakov@linaro.orgLink: https://lkml.kernel.org/r/20201209125153.10533-1-georgi.djakov@linaro.org
Signed-off-by: Liam Mark
Signed-off-by: Georgi Djakov
Acked-by: Vlastimil Babka
Acked-by: Joonsoo Kim
Cc: Jonathan Corbet
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds(cherry picked from commit 9cc7e96aa846f9086431d6c2d33ff9ab42d72b2d)
Bug: 175129313
Signed-off-by: Suren Baghdasaryan
Change-Id: I5e246ea009c7e9e34c1cc608bcd3196fc0e623b4 -
Formerly cuttlefish and goldfish had separate symbol lists.
The defconfigs and symbol lists were unified recently. However, the
symbol lists should conform to this naming convention.Generated with
BUILD_CONFIG=common/build.config.gki.aarch64 build/build.sh;
BUILD_CONFIG= \
common-modules/virtual-device/build.config.virtual_device.aarch64 \
build/build.sh;
build/abi/extract_symbols out/android12-5.10/dist/ \
--whitelist common/android/abi_gki_aarch64_virtual_deviceTest: Treehugger
Bug: 176831960
Signed-off-by: Ram Muthiah
Change-Id: I21755fbd3e9ab6319fdf4fcd06e501d722fb7242 -
Free the pages parallely for a task that receives SIGKILL, from ULMK
process, using the oom_reaper. This freeing of pages will help to give
the pages to buddy system well advance.Add the boot param, reap_mem_when_killed_by=, that configures the
process name, the kill signal to a process from which makes its memory
reaped by oom reaper.As an example, when reap_mem_when_killed_by=lmkd, then all the processes
that receives the kill signal from lmkd is added to oom reaper.Not initializing this param makes this feature disabled.
Change-Id: I21adb95de5e380a80d7eb0b87d9b5b553f52e28a
Bug: 171763461
Signed-off-by: Charan Teja Reddy
Signed-off-by: Isaac J. Manjarres -
* aosp/upstream-f2fs-stable-linux-5.10.y:
fs-verity: move structs needed for file signing to UAPI header
fs-verity: rename "file measurement" to "file digest"
fs-verity: rename fsverity_signed_digest to fsverity_formatted_digest
fs-verity: remove filenames from file comments
fscrypt: allow deleting files with unsupported encryption policy
fscrypt: unexport fscrypt_get_encryption_info()
fscrypt: move fscrypt_require_key() to fscrypt_private.h
fscrypt: move body of fscrypt_prepare_setattr() out-of-line
fscrypt: introduce fscrypt_prepare_readdir()
ext4: don't call fscrypt_get_encryption_info() from dx_show_leaf()
ubifs: remove ubifs_dir_open()
f2fs: remove f2fs_dir_open()
ext4: remove ext4_dir_open()
fscrypt: simplify master key locking
fscrypt: remove unnecessary calls to fscrypt_require_key()
ubifs: prevent creating duplicate encrypted filenames
f2fs: prevent creating duplicate encrypted filenames
ext4: prevent creating duplicate encrypted filenames
fscrypt: add fscrypt_is_nokey_name()
fscrypt: remove kernel-internal constants from UAPI headerConflicts:
fs/crypto/hooks.cBug: 174873661
Signed-off-by: Jaegeuk Kim
Change-Id: Id56d42fc959242524628752223e9d773a2c8681c -
To be able to update addresses of an IPsec SA, as required by
supporting MOBIKEBug: 169169084
Signed-off-by: Yan Yan
Change-Id: I5aa3f3556d615e4f0695bb78cd3cad9e83851df5 -
Export get_page_owner symbol for loadable vendor
modules.Bug: 176277889
Change-Id: Iea0a8022e542d1223caf4a742a888647828ca7cc
Signed-off-by: Vijayanand Jitta -
Export lookup_page_ext symbol for loadable vendor
modules.Bug: 176277892
Change-Id: If7de83bf48c2867460ec88e61e0f709958dc5e16
Signed-off-by: Vijayanand Jitta -
Export get_slabinfo symbol for loadable vendor
modules.Bug: 176277895
Change-Id: I01870a370da9bf5db842ff14801d94ef79350560
Signed-off-by: Vijayanand Jitta
06 Jan, 2021
3 commits
-
Tested-by: Jon Hunter
Tested-by: Linux Kernel Functional Testing
Tested-by: Jeffrin Jose T
Tested-by: Shuah Khan
Tested-by: Guenter Roeck
Link: https://lore.kernel.org/r/20210104155708.800470590@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman -
[ Upstream commit 6268d7da4d192af339f4d688942b9ccb45a65e04 ]
There are multiple locations that open-code the release of the last
range in a device-dax instance. Consolidate this into a new
dev_dax_trim_range() helper.This also addresses a kmemleak report:
# cat /sys/kernel/debug/kmemleak
[..]
unreferenced object 0xffff976bd46f6240 (size 64):
comm "ndctl", pid 23556, jiffies 4299514316 (age 5406.733s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 20 c3 37 00 00 00 .......... .7...
ff ff ff 7f 38 00 00 00 00 00 00 00 00 00 00 00 ....8...........
backtrace:
[] __kmalloc_track_caller+0x136/0x379
[] krealloc+0x67/0x92
[] __alloc_dev_dax_range+0x73/0x25c
[] devm_create_dev_dax+0x27d/0x416
[] __dax_pmem_probe+0x1c9/0x1000 [dax_pmem_core]
[] dax_pmem_probe+0x10/0x1f [dax_pmem]
[] nvdimm_bus_probe+0x9d/0x340 [libnvdimm]
[] really_probe+0x230/0x48d
[] driver_probe_device+0x122/0x13b
[] device_driver_attach+0x5b/0x60
[] bind_store+0xb7/0xc3
[] drv_attr_store+0x27/0x31
[] sysfs_kf_write+0x4a/0x57
[] kernfs_fop_write+0x150/0x1e5
[] __vfs_write+0x1b/0x34
[] vfs_write+0xd8/0x1d1Reported-by: Jane Chu
Cc: Zhen Lei
Link: https://lore.kernel.org/r/160834570161.1791850.14911670304441510419.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams
Signed-off-by: Sasha Levin -
[ Upstream commit 82ef1370b0c1757ab4ce29f34c52b4e93839b0aa ]
Commit cfd732377221 ("ext4: add prefetching for block allocation
bitmaps") introduced block bitmap prefetch, and expects to read block
bitmaps of flex_bg through an IO. However, it seems to ignore the
value range of s_log_groups_per_flex. In the scenario where the value
of s_log_groups_per_flex is greater than 27, s_mb_prefetch or
s_mb_prefetch_limit will overflow, cause a divide zero exception.In addition, the logic of calculating nr is also flawed, because the
size of flexbg is fixed during a single mount, but s_mb_prefetch can
be modified, which causes nr to fail to meet the value condition of
[1, flexbg_size].To solve this problem, we need to set the upper limit of
s_mb_prefetch. Since we expect to load block bitmaps of a flex_bg
through an IO, we can consider determining a reasonable upper limit
among the IO limit parameters. After consideration, we chose
BLK_MAX_SEGMENT_SIZE. This is a good choice to solve divide zero
problem and avoiding performance degradation.[ Some minor code simplifications to make the changes easy to follow -- TYT ]
Reported-by: Tosk Robot
Signed-off-by: Chunguang Xu
Reviewed-by: Samuel Liao
Reviewed-by: Andreas Dilger
Link: https://lore.kernel.org/r/1607051143-24508-1-git-send-email-brookxu@tencent.com
Signed-off-by: Theodore Ts'o
Signed-off-by: Sasha Levin
