On 32-bit platforms, pgoff_t is 32 bits wide, so left-shifting
large arbitrary pgoff_t values by PAGE_SHIFT performs 32-bit arithmetic
and silently truncates the result for pages beyond the 4 GiB boundary.
Cast the page index to loff_t before shifting to produce a correct
64-bit byte offset.
Fixes: 386292919c ("erofs: introduce readmore decompression strategy")
Fixes: 307210c262 ("erofs: verify metadata accesses for file-backed mounts")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
- Remove EROFS_MAP_ENCODED since it was always set together with
EROFS_MAP_MAPPED for compressed extents and checked redundantly;
- Replace the EROFS_MAP_FULL_MAPPED flag with the opposite
EROFS_MAP_PARTIAL_MAPPED flag so that extents are implicitly
fully mapped initially to simplify the logic;
- Make fragment extents independent of EROFS_MAP_MAPPED since
they are not directly allocated on disk; thus fragment extents
are no longer twisted with mapped extents.
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
folio_trylock() in erofs_try_to_free_all_cached_folios() may
successfully acquire the folio lock, but the subsequent check
for erofs_folio_is_managed() can skip unlocking when the folio
is not managed by EROFS.
As Gao Xiang pointed out, this condition should not happen in
practice because compressed_bvecs[] only holds valid cached folios
at this point — any non-managed folio would have already been
detached by z_erofs_cache_release_folio() under folio lock.
Fix this by adding DBG_BUGON() to catch unexpected folios
and ensure folio_unlock() is always called.
Suggested-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chunhai Guo <guochunhai@vivo.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
The bio completion path in the process context (e.g. dm-verity)
will directly call into decompression rather than trigger another
workqueue context for minimal scheduling latencies, which can
then call vm_map_ram() with GFP_KERNEL.
Due to insufficient memory, vm_map_ram() may generate memory
swapping I/O, which can cause submit_bio_wait to deadlock
in some scenarios.
Trimmed down the call stack, as follows:
f2fs_submit_read_io
submit_bio //bio_list is initialized.
mmc_blk_mq_recovery
z_erofs_endio
vm_map_ram
__pte_alloc_kernel
__alloc_pages_direct_reclaim
shrink_folio_list
__swap_writepage
submit_bio_wait //bio_list is non-NULL, hang!!!
Use memalloc_noio_{save,restore}() to wrap up this path.
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Jiucheng Xu <jiucheng.xu@amlogic.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Compressed folios for ztailpacking pclusters must be valid before adding
these pclusters to I/O chains. Otherwise, z_erofs_decompress_pcluster()
may assume they are already valid and then trigger a NULL pointer
dereference.
It is somewhat hard to reproduce because the inline data is in the same
block as the tail of the compressed indexes, which are usually read just
before. However, it may still happen if a fatal signal arrives while
read_mapping_folio() is running, as shown below:
erofs: (device dm-1): z_erofs_pcluster_begin: failed to get inline data -4
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
...
pc : z_erofs_decompress_queue+0x4c8/0xa14
lr : z_erofs_decompress_queue+0x160/0xa14
sp : ffffffc08b3eb3a0
x29: ffffffc08b3eb570 x28: ffffffc08b3eb418 x27: 0000000000001000
x26: ffffff8086ebdbb8 x25: ffffff8086ebdbb8 x24: 0000000000000001
x23: 0000000000000008 x22: 00000000fffffffb x21: dead000000000700
x20: 00000000000015e7 x19: ffffff808babb400 x18: ffffffc089edc098
x17: 00000000c006287d x16: 00000000c006287d x15: 0000000000000004
x14: ffffff80ba8f8000 x13: 0000000000000004 x12: 00000006589a77c9
x11: 0000000000000015 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000040 x4 : ffffffffffffffe0 x3 : 0000000000000020
x2 : 0000000000000008 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
z_erofs_decompress_queue+0x4c8/0xa14
z_erofs_runqueue+0x908/0x97c
z_erofs_read_folio+0x128/0x228
filemap_read_folio+0x68/0x128
filemap_get_pages+0x44c/0x8b4
filemap_read+0x12c/0x5b8
generic_file_read_iter+0x4c/0x15c
do_iter_readv_writev+0x188/0x1e0
vfs_iter_read+0xac/0x1a4
backing_file_read_iter+0x170/0x34c
ovl_read_iter+0xf0/0x140
vfs_read+0x28c/0x344
ksys_read+0x80/0xf0
__arm64_sys_read+0x24/0x34
invoke_syscall+0x60/0x114
el0_svc_common+0x88/0xe4
do_el0_svc+0x24/0x30
el0_svc+0x40/0xa8
el0t_64_sync_handler+0x70/0xbc
el0t_64_sync+0x1bc/0x1c0
Fix this by reading the inline data before allocating and adding
the pclusters to the I/O chains.
Fixes: cecf864d3d ("erofs: support inline data decompression")
Reported-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Reviewed-and-tested-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
The trace_erofs_read_folio accesses inode information through folio,
but this method fails if the real inode is not associated with the
folio(such as in the upcoming page cache sharing case). Therefore,
we pass the real inode to it so that the inode information can be
printed out in that case.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
- Get rid of `sbi->opt.max_sync_decompress_pages` since it's fixed as
3 all the time;
- Add Z_EROFS_MAX_SYNC_DECOMPRESS_BYTES in bytes instead of in pages,
since for non-4K pages, 3-page limitation makes no sense;
- Move `sync_decompress` to sbi to avoid unexpected remount impact;
- Fold z_erofs_is_sync_decompress() into its caller;
- Better description of sysfs entry `sync_decompress`.
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
EROFS may allocate temporary pages using GFP_NOWAIT | GFP_NORETRY
when pcl->besteffort is off (e.g., for readahead requests).
If the allocation fails, the original request will fall back to
synchronous read, so the failure is transient.
Such fallback can frequently happen in low memory scenarios, but since
these failures are expected and temporary, avoid printing error
messages like below:
[ 7425.184264] erofs (device sr0): failed to decompress (lz4) -ENOMEM @ pa 148447232 size 28672 => 26788
[ 7426.244267] erofs (device sr0): failed to decompress (lz4) -ENOMEM @ pa 149422080 size 28672 => 15903
[ 7426.245508] erofs (device sr0): failed to decompress (lz4) -ENOMEM @ pa 138440704 size 28672 => 39294
...
[ 7504.258373] erofs (device sr0): failed to decompress (lz4) -ENOMEM @ pa 93581312 size 20480 => 47366
Fixes: 831faabed8 ("erofs: improve decompression error reporting")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
%pe will print a symbolic error name (e.g,. -ENOMEM), opposed to the
raw errno (e.g,. -12) produced by PTR_ERR().
Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
erofs readahead could fail with ENOMEM under the memory pressure because
it tries to alloc_page with GFP_NOWAIT | GFP_NORETRY, while GFP_KERNEL
for a regular read. And if readahead fails (with non-uptodate folios),
the original request will then fall back to synchronous read, and
`.read_folio()` should return appropriate errnos.
However, in scenarios where readahead and read operations compete,
read operation could return an unintended EIO because of an incorrect
error propagation.
To resolve this, this patch modifies the behavior so that, when the
PCL is for read(which means pcl.besteffort is true), it attempts actual
decompression instead of propagating the privios error except initial EIO.
- Page size: 4K
- The original size of FileA: 16K
- Compress-ratio per PCL: 50% (Uncompressed 8K -> Compressed 4K)
[page0, page1] [page2, page3]
[PCL0]---------[PCL1]
- functions declaration:
. pread(fd, buf, count, offset)
. readahead(fd, offset, count)
- Thread A tries to read the last 4K
- Thread B tries to do readahead 8K from 4K
- RA, besteffort == false
- R, besteffort == true
<process A> <process B>
pread(FileA, buf, 4K, 12K)
do readahead(page3) // failed with ENOMEM
wait_lock(page3)
if (!uptodate(page3))
goto do_read
readahead(FileA, 4K, 8K)
// Here create PCL-chain like below:
// [null, page1] [page2, null]
// [PCL0:RA]-----[PCL1:RA]
...
do read(page3) // found [PCL1:RA] and add page3 into it,
// and then, change PCL1 from RA to R
...
// Now, PCL-chain is as below:
// [null, page1] [page2, page3]
// [PCL0:RA]-----[PCL1:R]
// try to decompress PCL-chain...
z_erofs_decompress_queue
err = 0;
// failed with ENOMEM, so page 1
// only for RA will not be uptodated.
// it's okay.
err = decompress([PCL0:RA], err)
// However, ENOMEM propagated to next
// PCL, even though PCL is not only
// for RA but also for R. As a result,
// it just failed with ENOMEM without
// trying any decompression, so page2
// and page3 will not be uptodated.
** BUG HERE ** --> err = decompress([PCL1:R], err)
return err as ENOMEM
...
wait_lock(page3)
if (!uptodate(page3))
return EIO <-- Return an unexpected EIO!
...
Fixes: 2349d2fa02 ("erofs: sunset unneeded NOFAILs")
Cc: stable@vger.kernel.org
Reviewed-by: Jaewook Kim <jw5454.kim@samsung.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Junbeom Yeom <junbeom.yeom@samsung.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
- Support for userspace handling of synchronous external aborts (SEAs),
allowing the VMM to potentially handle the abort in a non-fatal
manner.
- Large rework of the VGIC's list register handling with the goal of
supporting more active/pending IRQs than available list registers in
hardware. In addition, the VGIC now supports EOImode==1 style
deactivations for IRQs which may occur on a separate vCPU than the
one that acked the IRQ.
- Support for FEAT_XNX (user / privileged execute permissions) and
FEAT_HAF (hardware update to the Access Flag) in the software page
table walkers and shadow MMU.
- Allow page table destruction to reschedule, fixing long need_resched
latencies observed when destroying a large VM.
- Minor fixes to KVM and selftests
Loongarch:
- Get VM PMU capability from HW GCFG register.
- Add AVEC basic support.
- Use 64-bit register definition for EIOINTC.
- Add KVM timer test cases for tools/selftests.
RISC/V:
- SBI message passing (MPXY) support for KVM guest
- Give a new, more specific error subcode for the case when in-kernel
AIA virtualization fails to allocate IMSIC VS-file
- Support KVM_DIRTY_LOG_INITIALLY_SET, enabling dirty log gradually
in small chunks
- Fix guest page fault within HLV* instructions
- Flush VS-stage TLB after VCPU migration for Andes cores
s390:
- Always allocate ESCA (Extended System Control Area), instead of
starting with the basic SCA and converting to ESCA with the
addition of the 65th vCPU. The price is increased number of
exits (and worse performance) on z10 and earlier processor;
ESCA was introduced by z114/z196 in 2010.
- VIRT_XFER_TO_GUEST_WORK support
- Operation exception forwarding support
- Cleanups
x86:
- Skip the costly "zap all SPTEs" on an MMIO generation wrap if MMIO SPTE
caching is disabled, as there can't be any relevant SPTEs to zap.
- Relocate a misplaced export.
- Fix an async #PF bug where KVM would clear the completion queue when the
guest transitioned in and out of paging mode, e.g. when handling an SMI and
then returning to paged mode via RSM.
- Leave KVM's user-return notifier registered even when disabling
virtualization, as long as kvm.ko is loaded. On reboot/shutdown, keeping
the notifier registered is ok; the kernel does not use the MSRs and the
callback will run cleanly and restore host MSRs if the CPU manages to
return to userspace before the system goes down.
- Use the checked version of {get,put}_user().
- Fix a long-lurking bug where KVM's lack of catch-up logic for periodic APIC
timers can result in a hard lockup in the host.
- Revert the periodic kvmclock sync logic now that KVM doesn't use a
clocksource that's subject to NTP corrections.
- Clean up KVM's handling of MMIO Stale Data and L1TF, and bury the latter
behind CONFIG_CPU_MITIGATIONS.
- Context switch XCR0, XSS, and PKRU outside of the entry/exit fast path;
the only reason they were handled in the fast path was to paper of a bug
in the core #MC code, and that has long since been fixed.
- Add emulator support for AVX MOV instructions, to play nice with emulated
devices whose guest drivers like to access PCI BARs with large multi-byte
instructions.
x86 (AMD):
- Fix a few missing "VMCB dirty" bugs.
- Fix the worst of KVM's lack of EFER.LMSLE emulation.
- Add AVIC support for addressing 4k vCPUs in x2AVIC mode.
- Fix incorrect handling of selective CR0 writes when checking intercepts
during emulation of L2 instructions.
- Fix a currently-benign bug where KVM would clobber SPEC_CTRL[63:32] on
VMRUN and #VMEXIT.
- Fix a bug where KVM corrupt the guest code stream when re-injecting a soft
interrupt if the guest patched the underlying code after the VM-Exit, e.g.
when Linux patches code with a temporary INT3.
- Add KVM_X86_SNP_POLICY_BITS to advertise supported SNP policy bits to
userspace, and extend KVM "support" to all policy bits that don't require
any actual support from KVM.
x86 (Intel):
- Use the root role from kvm_mmu_page to construct EPTPs instead of the
current vCPU state, partly as worthwhile cleanup, but mostly to pave the
way for tracking per-root TLB flushes, and elide EPT flushes on pCPU
migration if the root is clean from a previous flush.
- Add a few missing nested consistency checks.
- Rip out support for doing "early" consistency checks via hardware as the
functionality hasn't been used in years and is no longer useful in general;
replace it with an off-by-default module param to WARN if hardware fails
a check that KVM does not perform.
- Fix a currently-benign bug where KVM would drop the guest's SPEC_CTRL[63:32]
on VM-Enter.
- Misc cleanups.
- Overhaul the TDX code to address systemic races where KVM (acting on behalf
of userspace) could inadvertantly trigger lock contention in the TDX-Module;
KVM was either working around these in weird, ugly ways, or was simply
oblivious to them (though even Yan's devilish selftests could only break
individual VMs, not the host kernel)
- Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a TDX vCPU,
if creating said vCPU failed partway through.
- Fix a few sparse warnings (bad annotation, 0 != NULL).
- Use struct_size() to simplify copying TDX capabilities to userspace.
- Fix a bug where TDX would effectively corrupt user-return MSR values if the
TDX Module rejects VP.ENTER and thus doesn't clobber host MSRs as expected.
Selftests:
- Fix a math goof in mmu_stress_test when running on a single-CPU system/VM.
- Forcefully override ARCH from x86_64 to x86 to play nice with specifying
ARCH=x86_64 on the command line.
- Extend a bunch of nested VMX to validate nested SVM as well.
- Add support for LA57 in the core VM_MODE_xxx macro, and add a test to
verify KVM can save/restore nested VMX state when L1 is using 5-level
paging, but L2 is not.
- Clean up the guest paging code in anticipation of sharing the core logic for
nested EPT and nested NPT.
guest_memfd:
- Add NUMA mempolicy support for guest_memfd, and clean up a variety of
rough edges in guest_memfd along the way.
- Define a CLASS to automatically handle get+put when grabbing a guest_memfd
from a memslot to make it harder to leak references.
- Enhance KVM selftests to make it easer to develop and debug selftests like
those added for guest_memfd NUMA support, e.g. where test and/or KVM bugs
often result in hard-to-debug SIGBUS errors.
- Misc cleanups.
Generic:
- Use the recently-added WQ_PERCPU when creating the per-CPU workqueue for
irqfd cleanup.
- Fix a goof in the dirty ring documentation.
- Fix choice of target for directed yield across different calls to
kvm_vcpu_on_spin(); the function was always starting from the first
vCPU instead of continuing the round-robin search.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"ARM:
- Support for userspace handling of synchronous external aborts
(SEAs), allowing the VMM to potentially handle the abort in a
non-fatal manner
- Large rework of the VGIC's list register handling with the goal of
supporting more active/pending IRQs than available list registers
in hardware. In addition, the VGIC now supports EOImode==1 style
deactivations for IRQs which may occur on a separate vCPU than the
one that acked the IRQ
- Support for FEAT_XNX (user / privileged execute permissions) and
FEAT_HAF (hardware update to the Access Flag) in the software page
table walkers and shadow MMU
- Allow page table destruction to reschedule, fixing long
need_resched latencies observed when destroying a large VM
- Minor fixes to KVM and selftests
Loongarch:
- Get VM PMU capability from HW GCFG register
- Add AVEC basic support
- Use 64-bit register definition for EIOINTC
- Add KVM timer test cases for tools/selftests
RISC/V:
- SBI message passing (MPXY) support for KVM guest
- Give a new, more specific error subcode for the case when in-kernel
AIA virtualization fails to allocate IMSIC VS-file
- Support KVM_DIRTY_LOG_INITIALLY_SET, enabling dirty log gradually
in small chunks
- Fix guest page fault within HLV* instructions
- Flush VS-stage TLB after VCPU migration for Andes cores
s390:
- Always allocate ESCA (Extended System Control Area), instead of
starting with the basic SCA and converting to ESCA with the
addition of the 65th vCPU. The price is increased number of exits
(and worse performance) on z10 and earlier processor; ESCA was
introduced by z114/z196 in 2010
- VIRT_XFER_TO_GUEST_WORK support
- Operation exception forwarding support
- Cleanups
x86:
- Skip the costly "zap all SPTEs" on an MMIO generation wrap if MMIO
SPTE caching is disabled, as there can't be any relevant SPTEs to
zap
- Relocate a misplaced export
- Fix an async #PF bug where KVM would clear the completion queue
when the guest transitioned in and out of paging mode, e.g. when
handling an SMI and then returning to paged mode via RSM
- Leave KVM's user-return notifier registered even when disabling
virtualization, as long as kvm.ko is loaded. On reboot/shutdown,
keeping the notifier registered is ok; the kernel does not use the
MSRs and the callback will run cleanly and restore host MSRs if the
CPU manages to return to userspace before the system goes down
- Use the checked version of {get,put}_user()
- Fix a long-lurking bug where KVM's lack of catch-up logic for
periodic APIC timers can result in a hard lockup in the host
- Revert the periodic kvmclock sync logic now that KVM doesn't use a
clocksource that's subject to NTP corrections
- Clean up KVM's handling of MMIO Stale Data and L1TF, and bury the
latter behind CONFIG_CPU_MITIGATIONS
- Context switch XCR0, XSS, and PKRU outside of the entry/exit fast
path; the only reason they were handled in the fast path was to
paper of a bug in the core #MC code, and that has long since been
fixed
- Add emulator support for AVX MOV instructions, to play nice with
emulated devices whose guest drivers like to access PCI BARs with
large multi-byte instructions
x86 (AMD):
- Fix a few missing "VMCB dirty" bugs
- Fix the worst of KVM's lack of EFER.LMSLE emulation
- Add AVIC support for addressing 4k vCPUs in x2AVIC mode
- Fix incorrect handling of selective CR0 writes when checking
intercepts during emulation of L2 instructions
- Fix a currently-benign bug where KVM would clobber SPEC_CTRL[63:32]
on VMRUN and #VMEXIT
- Fix a bug where KVM corrupt the guest code stream when re-injecting
a soft interrupt if the guest patched the underlying code after the
VM-Exit, e.g. when Linux patches code with a temporary INT3
- Add KVM_X86_SNP_POLICY_BITS to advertise supported SNP policy bits
to userspace, and extend KVM "support" to all policy bits that
don't require any actual support from KVM
x86 (Intel):
- Use the root role from kvm_mmu_page to construct EPTPs instead of
the current vCPU state, partly as worthwhile cleanup, but mostly to
pave the way for tracking per-root TLB flushes, and elide EPT
flushes on pCPU migration if the root is clean from a previous
flush
- Add a few missing nested consistency checks
- Rip out support for doing "early" consistency checks via hardware
as the functionality hasn't been used in years and is no longer
useful in general; replace it with an off-by-default module param
to WARN if hardware fails a check that KVM does not perform
- Fix a currently-benign bug where KVM would drop the guest's
SPEC_CTRL[63:32] on VM-Enter
- Misc cleanups
- Overhaul the TDX code to address systemic races where KVM (acting
on behalf of userspace) could inadvertantly trigger lock contention
in the TDX-Module; KVM was either working around these in weird,
ugly ways, or was simply oblivious to them (though even Yan's
devilish selftests could only break individual VMs, not the host
kernel)
- Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a
TDX vCPU, if creating said vCPU failed partway through
- Fix a few sparse warnings (bad annotation, 0 != NULL)
- Use struct_size() to simplify copying TDX capabilities to userspace
- Fix a bug where TDX would effectively corrupt user-return MSR
values if the TDX Module rejects VP.ENTER and thus doesn't clobber
host MSRs as expected
Selftests:
- Fix a math goof in mmu_stress_test when running on a single-CPU
system/VM
- Forcefully override ARCH from x86_64 to x86 to play nice with
specifying ARCH=x86_64 on the command line
- Extend a bunch of nested VMX to validate nested SVM as well
- Add support for LA57 in the core VM_MODE_xxx macro, and add a test
to verify KVM can save/restore nested VMX state when L1 is using
5-level paging, but L2 is not
- Clean up the guest paging code in anticipation of sharing the core
logic for nested EPT and nested NPT
guest_memfd:
- Add NUMA mempolicy support for guest_memfd, and clean up a variety
of rough edges in guest_memfd along the way
- Define a CLASS to automatically handle get+put when grabbing a
guest_memfd from a memslot to make it harder to leak references
- Enhance KVM selftests to make it easer to develop and debug
selftests like those added for guest_memfd NUMA support, e.g. where
test and/or KVM bugs often result in hard-to-debug SIGBUS errors
- Misc cleanups
Generic:
- Use the recently-added WQ_PERCPU when creating the per-CPU
workqueue for irqfd cleanup
- Fix a goof in the dirty ring documentation
- Fix choice of target for directed yield across different calls to
kvm_vcpu_on_spin(); the function was always starting from the first
vCPU instead of continuing the round-robin search"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (260 commits)
KVM: arm64: at: Update AF on software walk only if VM has FEAT_HAFDBS
KVM: arm64: at: Use correct HA bit in TCR_EL2 when regime is EL2
KVM: arm64: Document KVM_PGTABLE_PROT_{UX,PX}
KVM: arm64: Fix spelling mistake "Unexpeced" -> "Unexpected"
KVM: arm64: Add break to default case in kvm_pgtable_stage2_pte_prot()
KVM: arm64: Add endian casting to kvm_swap_s[12]_desc()
KVM: arm64: Fix compilation when CONFIG_ARM64_USE_LSE_ATOMICS=n
KVM: arm64: selftests: Add test for AT emulation
KVM: arm64: nv: Expose hardware access flag management to NV guests
KVM: arm64: nv: Implement HW access flag management in stage-2 SW PTW
KVM: arm64: Implement HW access flag management in stage-1 SW PTW
KVM: arm64: Propagate PTW errors up to AT emulation
KVM: arm64: Add helper for swapping guest descriptor
KVM: arm64: nv: Use pgtable definitions in stage-2 walk
KVM: arm64: Handle endianness in read helper for emulated PTW
KVM: arm64: nv: Stop passing vCPU through void ptr in S2 PTW
KVM: arm64: Call helper for reading descriptors directly
KVM: arm64: nv: Advertise support for FEAT_XNX
KVM: arm64: Teach ptdump about FEAT_XNX permissions
KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functions
...
Change the return type of decompress() from `int` to `const char *` to
provide more informative error diagnostics:
- A NULL return indicates successful decompression;
- If IS_ERR(ptr) is true, the return value encodes a standard negative
errno (e.g., -ENOMEM, -EOPNOTSUPP) identifying the specific error;
- Otherwise, a non-NULL return points to a human-readable error string,
and the corresponding error code should be treated as -EFSCORRUPTED.
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Add a mempolicy parameter to filemap_alloc_folio() to enable NUMA-aware
page cache allocations. This will be used by upcoming changes to
support NUMA policies in guest-memfd, where guest_memory need to be
allocated NUMA policy specified by VMM.
All existing users pass NULL maintaining current behavior.
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Tested-by: Ashish Kalra <ashish.kalra@amd.com>
Link: https://lore.kernel.org/r/20250827175247.83322-4-shivankg@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
It is already performed in z_erofs_map_blocks_fo().
Also align the error message with that used for the uncompressed
inline layout.
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Since all real encoded extents (directly handled by the decompression
subsystem) have a sane, limited maximum decoded length
(Z_EROFS_PCLUSTER_MAX_DSIZE), and the read-more policy is only applied
if needed.
However, it makes no sense to read more for non-encoded maps, such as
fragment extents, since such extents can be huge (up to i_size) and
there is no benefit to reading more at this layer.
For normal images, it does not really matter, but for crafted images
generated by syzbot, excessively large fragment extents can cause
read-more to run for an overly long time.
Reported-and-tested-by: syzbot+1a9af3ef3c84c5e14dcc@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/68c8583d.050a0220.2ff435.03a3.GAE@google.com
Fixes: b44686c839 ("erofs: fix large fragment handling")
Fixes: b15b2e307c ("erofs: support on-disk compressed fragments data")
Reviewed-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Since EROFS handles decompression in non-atomic contexts due to
uncontrollable decompression latencies and vmap() usage, it tries
to detect atomic contexts and only kicks off a kworker on demand
in order to reduce unnecessary scheduling overhead.
However, the current approach is insufficient and can lead to
sleeping function calls in invalid contexts, causing kernel
warnings and potential system instability. See the stacktrace [1]
and previous discussion [2].
The current implementation only checks rcu_read_lock_any_held(),
which behaves inconsistently across different kernel configurations:
- When CONFIG_DEBUG_LOCK_ALLOC is enabled: correctly detects
RCU critical sections by checking rcu_lock_map
- When CONFIG_DEBUG_LOCK_ALLOC is disabled: compiles to
"!preemptible()", which only checks preempt_count and misses
RCU critical sections
This patch introduces z_erofs_in_atomic() to provide comprehensive
atomic context detection:
1. Check RCU preemption depth when CONFIG_PREEMPTION is enabled,
as RCU critical sections may not affect preempt_count but still
require atomic handling
2. Always use async processing when CONFIG_PREEMPT_COUNT is disabled,
as preemption state cannot be reliably determined
3. Fall back to standard preemptible() check for remaining cases
The function replaces the previous complex condition check and ensures
that z_erofs always uses (kthread_)work in atomic contexts to minimize
scheduling overhead and prevent sleeping in invalid contexts.
[1] Problem stacktrace
[ 61.266692] BUG: sleeping function called from invalid context at kernel/locking/rtmutex_api.c:510
[ 61.266702] in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 107, name: irq/54-ufshcd
[ 61.266704] preempt_count: 0, expected: 0
[ 61.266705] RCU nest depth: 2, expected: 0
[ 61.266710] CPU: 0 UID: 0 PID: 107 Comm: irq/54-ufshcd Tainted: G W O 6.12.17 #1
[ 61.266714] Tainted: [W]=WARN, [O]=OOT_MODULE
[ 61.266715] Hardware name: schumacher (DT)
[ 61.266717] Call trace:
[ 61.266718] dump_backtrace+0x9c/0x100
[ 61.266727] show_stack+0x20/0x38
[ 61.266728] dump_stack_lvl+0x78/0x90
[ 61.266734] dump_stack+0x18/0x28
[ 61.266736] __might_resched+0x11c/0x180
[ 61.266743] __might_sleep+0x64/0xc8
[ 61.266745] mutex_lock+0x2c/0xc0
[ 61.266748] z_erofs_decompress_queue+0xe8/0x978
[ 61.266753] z_erofs_decompress_kickoff+0xa8/0x190
[ 61.266756] z_erofs_endio+0x168/0x288
[ 61.266758] bio_endio+0x160/0x218
[ 61.266762] blk_update_request+0x244/0x458
[ 61.266766] scsi_end_request+0x38/0x278
[ 61.266770] scsi_io_completion+0x4c/0x600
[ 61.266772] scsi_finish_command+0xc8/0xe8
[ 61.266775] scsi_complete+0x88/0x148
[ 61.266777] blk_mq_complete_request+0x3c/0x58
[ 61.266780] scsi_done_internal+0xcc/0x158
[ 61.266782] scsi_done+0x1c/0x30
[ 61.266783] ufshcd_compl_one_cqe+0x12c/0x438
[ 61.266786] __ufshcd_transfer_req_compl+0x2c/0x78
[ 61.266788] ufshcd_poll+0xf4/0x210
[ 61.266789] ufshcd_transfer_req_compl+0x50/0x88
[ 61.266791] ufshcd_intr+0x21c/0x7c8
[ 61.266792] irq_forced_thread_fn+0x44/0xd8
[ 61.266796] irq_thread+0x1a4/0x358
[ 61.266799] kthread+0x12c/0x138
[ 61.266802] ret_from_fork+0x10/0x20
[2] https://lore.kernel.org/r/58b661d0-0ebb-4b45-a10d-c5927fb791cd@paulmck-laptop
Signed-off-by: Junli Liu <liujunli@lixiang.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250805011957.911186-1-liujunli@lixiang.com
[ Gao Xiang: Use the original trace in v1. ]
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Thanks to the meta buffer infrastructure, metadata-compressed inodes are
just read from the metabox inode instead of the blockdevice (or backing
file) inode.
The same is true for shared extended attributes.
When metadata compression is enabled, inode numbers are divided from
on-disk NIDs because of non-LTS 32-bit application compatibility.
Co-developed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Bo Liu (OpenAnolis) <liubo03@inspur.com>
Acked-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250722003229.2121752-1-hsiangkao@linux.alibaba.com
- need_kmap is always true except for a ztailpacking case; thus, just
open-code that one;
- The upcoming metadata compression will add a new boolean, so simplify
this first.
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20250714090907.4095645-1-hsiangkao@linux.alibaba.com
The compressed data for the ztailpacking feature is fetched from
the metadata inode (e.g., bd_inode), which is folio-based.
Therefore, the folio interface should be used instead.
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250626085459.339830-1-hsiangkao@linux.alibaba.com
Fragments aren't limited by Z_EROFS_PCLUSTER_MAX_DSIZE. However, if
a fragment's logical length is larger than Z_EROFS_PCLUSTER_MAX_DSIZE
but the fragment is not the whole inode, it currently returns
-EOPNOTSUPP because m_flags has the wrong EROFS_MAP_ENCODED flag set.
It is not intended by design but should be rare, as it can only be
reproduced by mkfs with `-Eall-fragments` in a specific case.
Let's normalize fragment m_flags using the new EROFS_MAP_FRAGMENT.
Reported-by: Axel Fontaine <axel@axelfontaine.com>
Closes: https://github.com/erofs/erofs-utils/issues/23
Fixes: 7c3ca1838a ("erofs: restrict pcluster size limitations")
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250711195826.3601157-1-hsiangkao@linux.alibaba.com
When attempting to use an archive file, such as APEX on android,
as a file-backed mount source, it fails because EROFS image within
the archive file does not start at offset 0. As a result, a loop
or a dm device is still needed to attach the image file at an
appropriate offset first. Similarly, if an EROFS image within a
block device does not start at offset 0, it cannot be mounted
directly either.
To address this issue, this patch adds a new mount option `fsoffset=x'
to accept a start offset for the primary device. The offset should be
aligned to the block size. EROFS will add this offset before performing
read requests.
Signed-off-by: Sheng Yong <shengyong1@xiaomi.com>
Signed-off-by: Wang Shuai <wangshuai12@xiaomi.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250517090544.2687651-1-shengyong1@xiaomi.com
[ Gao Xiang: minor update on documentation and the error message. ]
Reviewed-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Currently, when EROFS is built with per-CPU workers, the workers are
started and CPU hotplug hooks are registered during module initialization.
This leads to unnecessary worker start/stop cycles during CPU hotplug
events, particularly on Android devices that frequently suspend and resume.
This change defers the initialization of per-CPU workers and the
registration of CPU hotplug hooks until the first EROFS mount. This
ensures that these resources are only allocated and managed when EROFS is
actually in use.
The tear down of per-CPU workers and unregistration of CPU hotplug hooks
still occurs during z_erofs_exit_subsystem(), but only if they were
initialized.
Signed-off-by: Sandeep Dhavale <dhavale@google.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20250506225743.308517-1-dhavale@google.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
When compressed data deduplication is enabled, multiple logical extents
may reference the same compressed physical cluster.
The previous commit 94c43de735 ("erofs: fix wrong primary bvec
selection on deduplicated extents") already avoids using shortened
bvecs. However, in such cases, the extra temporary buffers also
need to be preserved for later use in z_erofs_fill_other_copies() to
to prevent data corruption.
IOWs, extra temporary buffers have to be retained not only due to
varying start relative offsets (`pageofs_out`, as indicated by
`pcl->multibases`) but also because of shortened bvecs.
android.hardware.graphics.composer@2.1.so : 270696 bytes
0: 0.. 204185 | 204185 : 628019200.. 628084736 | 65536
-> 1: 204185.. 225536 | 21351 : 544063488.. 544129024 | 65536
2: 225536.. 270696 | 45160 : 0.. 0 | 0
com.android.vndk.v28.apex : 93814897 bytes
...
364: 53869896..54095257 | 225361 : 543997952.. 544063488 | 65536
-> 365: 54095257..54309344 | 214087 : 544063488.. 544129024 | 65536
366: 54309344..54514557 | 205213 : 544129024.. 544194560 | 65536
...
Both 204185 and 54095257 have the same start relative offset of 3481,
but the logical page 55 of `android.hardware.graphics.composer@2.1.so`
ranges from 225280 to 229632, forming a shortened bvec [225280, 225536)
that cannot be used for decompressing the range from 54095257 to
54309344 of `com.android.vndk.v28.apex`.
Since `pcl->multibases` is already meaningless, just mark `be->keepxcpy`
on demand for simplicity.
Again, this issue can only lead to data corruption if `-Ededupe` is on.
Fixes: 94c43de735 ("erofs: fix wrong primary bvec selection on deduplicated extents")
Reviewed-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250506101850.191506-1-hsiangkao@linux.alibaba.com
Remove duplicate code in function z_erofs_register_pcluster()
Signed-off-by: Bo Liu <liubo03@inspur.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250410042048.3044-2-liubo03@inspur.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
We're almost there. It's straight-forward to adapt the current
decompression subsystem to support unaligned encoded (compressed) data.
Note that unaligned data is not encouraged because of worse I/O and
caching efficiency unless the corresponding compressor doesn't support
fixed-sized output compression natively like Zstd.
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Acked-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20250310095459.2620647-10-hsiangkao@linux.alibaba.com
- Rename erofs_init_managed_cache() to z_erofs_init_super();
- Move the initialization of managed_pslots into z_erofs_init_super() too;
- Move z_erofs_init_super() and packed inode preparation upwards, before
the root inode initialization.
Therefore, the root directory can also be compressible.
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Acked-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20250317054840.3483000-1-hsiangkao@linux.alibaba.com
It seems that all compressors need those two values, so just move
them into the common structure.
`struct z_erofs_lz4_decompress_ctx` can be dropped too.
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250305124007.1810731-1-hsiangkao@linux.alibaba.com
Since EROFS_KMAP_ATOMIC is no longer valid, get rid of erofs_kmap_type too.
Signed-off-by: Bo Liu <liubo03@inspur.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20250217093141.2659-1-liubo03@inspur.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
All users of lockref_init() now initialize the count to 1, so hardcode
that and remove the count argument.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Link: https://lore.kernel.org/r/20250130135624.1899988-4-agruenba@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
- Micro-optimize superblock checksum;
- Avoid overly large bvecs[] for file-backed mounts;
- Some leftover folio conversion in z_erofs_bind_cache();
- Minor bugfixes and cleanups.
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Merge tag 'erofs-for-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs
Pull erofs updates from Gao Xiang:
"Still no new features for this cycle, as some ongoing improvements
remain premature for now.
This includes a micro-optimization for the superblock checksum, along
with minor bugfixes and code cleanups, as usual:
- Micro-optimize superblock checksum
- Avoid overly large bvecs[] for file-backed mounts
- Some leftover folio conversion in z_erofs_bind_cache()
- Minor bugfixes and cleanups"
* tag 'erofs-for-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
erofs: refine z_erofs_get_extent_compressedlen()
erofs: remove dead code in erofs_fc_parse_param
erofs: return SHRINK_EMPTY if no objects to free
erofs: convert z_erofs_bind_cache() to folios
erofs: tidy up zdata.c
erofs: get rid of `z_erofs_next_pcluster_t`
erofs: simplify z_erofs_load_compact_lcluster()
erofs: fix potential return value overflow of z_erofs_shrink_scan()
erofs: shorten bvecs[] for file-backed mounts
erofs: micro-optimize superblock checksum
fs: erofs: xattr.c change kzalloc to kcalloc
1) Per-CPU kthreads must stay affine to a single CPU and never execute
relevant code on any other CPU. This is currently handled by smpboot
code which takes care of CPU-hotplug operations. Affinity here is
a correctness constraint.
2) Some kthreads _have_ to be affine to a specific set of CPUs and can't
run anywhere else. The affinity is set through kthread_bind_mask()
and the subsystem takes care by itself to handle CPU-hotplug
operations. Affinity here is assumed to be a correctness constraint.
3) Per-node kthreads _prefer_ to be affine to a specific NUMA node. This
is not a correctness constraint but merely a preference in terms of
memory locality. kswapd and kcompactd both fall into this category.
The affinity is set manually like for any other task and CPU-hotplug
is supposed to be handled by the relevant subsystem so that the task
is properly reaffined whenever a given CPU from the node comes up.
Also care should be taken so that the node affinity doesn't cross
isolated (nohz_full) cpumask boundaries.
4) Similar to the previous point except kthreads have a _preferred_
affinity different than a node. Both RCU boost kthreads and RCU
exp kworkers fall into this category as they refer to "RCU nodes"
from a distinctly distributed tree.
Currently the preferred affinity patterns (3 and 4) have at least 4
identified users, with more or less success when it comes to handle
CPU-hotplug operations and CPU isolation. Each of which do it in its own
ad-hoc way.
This is an infrastructure proposal to handle this with the following API
changes:
_ kthread_create_on_node() automatically affines the created kthread to
its target node unless it has been set as per-cpu or bound with
kthread_bind[_mask]() before the first wake-up.
- kthread_affine_preferred() is a new function that can be called right
after kthread_create_on_node() to specify a preferred affinity
different than the specified node.
When the preferred affinity can't be applied because the possible
targets are offline or isolated (nohz_full), the kthread is affine
to the housekeeping CPUs (which means to all online CPUs most of the
time or only the non-nohz_full CPUs when nohz_full= is set).
kswapd, kcompactd, RCU boost kthreads and RCU exp kworkers have been
converted, along with a few old drivers.
Summary of the changes:
* Consolidate a bunch of ad-hoc implementations of kthread_run_on_cpu()
* Introduce task_cpu_fallback_mask() that defines the default last
resort affinity of a task to become nohz_full aware
* Add some correctness check to ensure kthread_bind() is always called
before the first kthread wake up.
* Default affine kthread to its preferred node.
* Convert kswapd / kcompactd and remove their halfway working ad-hoc
affinity implementation
* Implement kthreads preferred affinity
* Unify kthread worker and kthread API's style
* Convert RCU kthreads to the new API and remove the ad-hoc affinity
implementation.
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Merge tag 'kthread-for-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks
Pull kthread updates from Frederic Weisbecker:
"Kthreads affinity follow either of 4 existing different patterns:
1) Per-CPU kthreads must stay affine to a single CPU and never
execute relevant code on any other CPU. This is currently handled
by smpboot code which takes care of CPU-hotplug operations.
Affinity here is a correctness constraint.
2) Some kthreads _have_ to be affine to a specific set of CPUs and
can't run anywhere else. The affinity is set through
kthread_bind_mask() and the subsystem takes care by itself to
handle CPU-hotplug operations. Affinity here is assumed to be a
correctness constraint.
3) Per-node kthreads _prefer_ to be affine to a specific NUMA node.
This is not a correctness constraint but merely a preference in
terms of memory locality. kswapd and kcompactd both fall into this
category. The affinity is set manually like for any other task and
CPU-hotplug is supposed to be handled by the relevant subsystem so
that the task is properly reaffined whenever a given CPU from the
node comes up. Also care should be taken so that the node affinity
doesn't cross isolated (nohz_full) cpumask boundaries.
4) Similar to the previous point except kthreads have a _preferred_
affinity different than a node. Both RCU boost kthreads and RCU
exp kworkers fall into this category as they refer to "RCU nodes"
from a distinctly distributed tree.
Currently the preferred affinity patterns (3 and 4) have at least 4
identified users, with more or less success when it comes to handle
CPU-hotplug operations and CPU isolation. Each of which do it in its
own ad-hoc way.
This is an infrastructure proposal to handle this with the following
API changes:
- kthread_create_on_node() automatically affines the created kthread
to its target node unless it has been set as per-cpu or bound with
kthread_bind[_mask]() before the first wake-up.
- kthread_affine_preferred() is a new function that can be called
right after kthread_create_on_node() to specify a preferred
affinity different than the specified node.
When the preferred affinity can't be applied because the possible
targets are offline or isolated (nohz_full), the kthread is affine to
the housekeeping CPUs (which means to all online CPUs most of the time
or only the non-nohz_full CPUs when nohz_full= is set).
kswapd, kcompactd, RCU boost kthreads and RCU exp kworkers have been
converted, along with a few old drivers.
Summary of the changes:
- Consolidate a bunch of ad-hoc implementations of
kthread_run_on_cpu()
- Introduce task_cpu_fallback_mask() that defines the default last
resort affinity of a task to become nohz_full aware
- Add some correctness check to ensure kthread_bind() is always
called before the first kthread wake up.
- Default affine kthread to its preferred node.
- Convert kswapd / kcompactd and remove their halfway working ad-hoc
affinity implementation
- Implement kthreads preferred affinity
- Unify kthread worker and kthread API's style
- Convert RCU kthreads to the new API and remove the ad-hoc affinity
implementation"
* tag 'kthread-for-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks:
kthread: modify kernel-doc function name to match code
rcu: Use kthread preferred affinity for RCU exp kworkers
treewide: Introduce kthread_run_worker[_on_cpu]()
kthread: Unify kthread_create_on_cpu() and kthread_create_worker_on_cpu() automatic format
rcu: Use kthread preferred affinity for RCU boost
kthread: Implement preferred affinity
mm: Create/affine kswapd to its preferred node
mm: Create/affine kcompactd to its preferred node
kthread: Default affine kthread to its preferred NUMA node
kthread: Make sure kthread hasn't started while binding it
sched,arm64: Handle CPU isolation on last resort fallback rq selection
arm64: Exclude nohz_full CPUs from 32bits el0 support
lib: test_objpool: Use kthread_run_on_cpu()
kallsyms: Use kthread_run_on_cpu()
soc/qman: test: Use kthread_run_on_cpu()
arm/bL_switcher: Use kthread_run_on_cpu()
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Merge tag 'vfs-6.14-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Features:
- Support caching symlink lengths in inodes
The size is stored in a new union utilizing the same space as
i_devices, thus avoiding growing the struct or taking up any more
space
When utilized it dodges strlen() in vfs_readlink(), giving about
1.5% speed up when issuing readlink on /initrd.img on ext4
- Add RWF_DONTCACHE iocb and FOP_DONTCACHE file_operations flag
If a file system supports uncached buffered IO, it may set
FOP_DONTCACHE and enable support for RWF_DONTCACHE.
If RWF_DONTCACHE is attempted without the file system supporting
it, it'll get errored with -EOPNOTSUPP
- Enable VBOXGUEST and VBOXSF_FS on ARM64
Now that VirtualBox is able to run as a host on arm64 (e.g. the
Apple M3 processors) we can enable VBOXSF_FS (and in turn
VBOXGUEST) for this architecture.
Tested with various runs of bonnie++ and dbench on an Apple MacBook
Pro with the latest Virtualbox 7.1.4 r165100 installed
Cleanups:
- Delay sysctl_nr_open check in expand_files()
- Use kernel-doc includes in fiemap docbook
- Use page->private instead of page->index in watch_queue
- Use a consume fence in mnt_idmap() as it's heavily used in
link_path_walk()
- Replace magic number 7 with ARRAY_SIZE() in fc_log
- Sort out a stale comment about races between fd alloc and dup2()
- Fix return type of do_mount() from long to int
- Various cosmetic cleanups for the lockref code
Fixes:
- Annotate spinning as unlikely() in __read_seqcount_begin
The annotation already used to be there, but got lost in commit
52ac39e5db ("seqlock: seqcount_t: Implement all read APIs as
statement expressions")
- Fix proc_handler for sysctl_nr_open
- Flush delayed work in delayed fput()
- Fix grammar and spelling in propagate_umount()
- Fix ESP not readable during coredump
In /proc/PID/stat, there is the kstkesp field which is the stack
pointer of a thread. While the thread is active, this field reads
zero. But during a coredump, it should have a valid value
However, at the moment, kstkesp is zero even during coredump
- Don't wake up the writer if the pipe is still full
- Fix unbalanced user_access_end() in select code"
* tag 'vfs-6.14-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (28 commits)
gfs2: use lockref_init for qd_lockref
erofs: use lockref_init for pcl->lockref
dcache: use lockref_init for d_lockref
lockref: add a lockref_init helper
lockref: drop superfluous externs
lockref: use bool for false/true returns
lockref: improve the lockref_get_not_zero description
lockref: remove lockref_put_not_zero
fs: Fix return type of do_mount() from long to int
select: Fix unbalanced user_access_end()
vbox: Enable VBOXGUEST and VBOXSF_FS on ARM64
pipe_read: don't wake up the writer if the pipe is still full
selftests: coredump: Add stackdump test
fs/proc: do_task_stat: Fix ESP not readable during coredump
fs: add RWF_DONTCACHE iocb and FOP_DONTCACHE file_operations flag
fs: sort out a stale comment about races between fd alloc and dup2
fs: Fix grammar and spelling in propagate_umount()
fs: fc_log replace magic number 7 with ARRAY_SIZE()
fs: use a consume fence in mnt_idmap()
file: flush delayed work in delayed fput()
...
The managed cache uses a pseudo inode to keep (necessary) compressed
data.
Currently, it still uses zero-order folios, so this is just a trivial
conversion, except that the use of the pagepool is temporarily dropped.
Drop some obsoleted comments too.
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250114034429.431408-4-hsiangkao@linux.alibaba.com
It was originally intended for tagged pointer reservation.
Now all encoded data can be represented uniformally with
`struct z_erofs_pcluster` as described in commit bf1aa03980
("erofs: sunset `struct erofs_workgroup`"), let's drop it too.
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250114034429.431408-2-hsiangkao@linux.alibaba.com
z_erofs_shrink_scan() could return small numbers due to the mistyped
`freed`.
Although I don't think it has any visible impact.
Fixes: 3883a79abd ("staging: erofs: introduce VLE decompression support")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250114040058.459981-1-hsiangkao@linux.alibaba.com
kthread_create() creates a kthread without running it yet. kthread_run()
creates a kthread and runs it.
On the other hand, kthread_create_worker() creates a kthread worker and
runs it.
This difference in behaviours is confusing. Also there is no way to
create a kthread worker and affine it using kthread_bind_mask() or
kthread_affine_preferred() before starting it.
Consolidate the behaviours and introduce kthread_run_worker[_on_cpu]()
that behaves just like kthread_run(). kthread_create_worker[_on_cpu]()
will now only create a kthread worker without starting it.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
kthread_create_on_cpu() uses the CPU argument as an implicit and unique
printf argument to add to the format whereas
kthread_create_worker_on_cpu() still relies on explicitly passing the
printf arguments. This difference in behaviour is error prone and
doesn't help standardizing per-CPU kthread names.
Unify the behaviours and convert kthread_create_worker_on_cpu() to
use the printf behaviour of kthread_create_on_cpu().
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Add a sysfs node to drop compression-related caches, currently used to
drop in-memory pclusters and cached compressed folios.
Signed-off-by: Chunhai Guo <guochunhai@vivo.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20241113041148.749129-1-guochunhai@vivo.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Once a pcluster is fully decompressed and there are no attached cached
folios, its corresponding `struct z_erofs_pcluster` will be freed. This
will significantly reduce the frequency of calls to erofs_shrink_scan()
and the memory allocated for `struct z_erofs_pcluster`.
The tables below show approximately a 96% reduction in the calls to
erofs_shrink_scan() and in the memory allocated for `struct
z_erofs_pcluster` after applying this patch. The results were obtained
by performing a test to copy a 4.1GB partition on ARM64 Android devices
running the 6.6 kernel with an 8-core CPU and 12GB of memory.
1. The reduction in calls to erofs_shrink_scan():
+-----------------+-----------+----------+---------+
| | w/o patch | w/ patch | diff |
+-----------------+-----------+----------+---------+
| Average (times) | 11390 | 390 | -96.57% |
+-----------------+-----------+----------+---------+
2. The reduction in memory released by erofs_shrink_scan():
+-----------------+-----------+----------+---------+
| | w/o patch | w/ patch | diff |
+-----------------+-----------+----------+---------+
| Average (Byte) | 133612656 | 4434552 | -96.68% |
+-----------------+-----------+----------+---------+
Signed-off-by: Chunhai Guo <guochunhai@vivo.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20241112043235.546164-1-guochunhai@vivo.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
`struct erofs_workgroup` was introduced to provide a unique header
for all physically indexed objects. However, after big pclusters and
shared pclusters are implemented upstream, it seems that all EROFS
encoded data (which requires transformation) can be represented with
`struct z_erofs_pcluster` directly.
Move all members into `struct z_erofs_pcluster` for simplicity.
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20241021035323.3280682-3-hsiangkao@linux.alibaba.com
