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Pull more Kbuild updates from Masahiro Yamada:
- Convert sh and sparc to use generic shell scripts to generate the
syscall headers
- refactor .gitignore files
- Update kernel/config_data.gz only when the content of the .config
is really changed, which avoids the unneeded re-link of vmlinux
- move "remove stale files" workarounds to scripts/remove-stale-files
- suppress unused-but-set-variable warnings by default for Clang
as well
- fix locale setting LANG=C to LC_ALL=C
- improve 'make distclean'
- always keep intermediate objects from scripts/link-vmlinux.sh
- move IF_ENABLED out of <linux/kconfig.h> to make it self-contained
- misc cleanups
* tag 'kbuild-v5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
linux/kconfig.h: replace IF_ENABLED() with PTR_IF() in <linux/kernel.h>
kbuild: Don't remove link-vmlinux temporary files on exit/signal
kbuild: remove the unneeded comments for external module builds
kbuild: make distclean remove tag files in sub-directories
kbuild: make distclean work against $(objtree) instead of $(srctree)
kbuild: refactor modname-multi by using suffix-search
kbuild: refactor fdtoverlay rule
kbuild: parameterize the .o part of suffix-search
arch: use cross_compiling to check whether it is a cross build or not
kbuild: remove ARCH=sh64 support from top Makefile
.gitignore: prefix local generated files with a slash
kbuild: replace LANG=C with LC_ALL=C
Makefile: Move -Wno-unused-but-set-variable out of GCC only block
kbuild: add a script to remove stale generated files
kbuild: update config_data.gz only when the content of .config is changed
.gitignore: ignore only top-level modules.builtin
.gitignore: move tags and TAGS close to other tag files
kernel/.gitgnore: remove stale timeconst.h and hz.bc
usr/include: refactor .gitignore
genksyms: fix stale comment
...
Pull block fixes from Jens Axboe:
- dasd spelling fixes (Bhaskar)
- Limit bio max size on multi-page bvecs to the hardware limit, to
avoid overly large bio's (and hence latencies). Originally queued for
the merge window, but needed a fix and was dropped from the initial
pull (Changheun)
- NVMe pull request (Christoph):
- reset the bdev to ns head when failover (Daniel Wagner)
- remove unsupported command noise (Keith Busch)
- misc passthrough improvements (Kanchan Joshi)
- fix controller ioctl through ns_head (Minwoo Im)
- fix controller timeouts during reset (Tao Chiu)
- rnbd fixes/cleanups (Gioh, Md, Dima)
- Fix iov_iter re-expansion (yangerkun)
* tag 'block-5.13-2021-05-07' of git://git.kernel.dk/linux-block:
block: reexpand iov_iter after read/write
nvmet: remove unsupported command noise
nvme-multipath: reset bdev to ns head when failover
nvme-pci: fix controller reset hang when racing with nvme_timeout
nvme: move the fabrics queue ready check routines to core
nvme: avoid memset for passthrough requests
nvme: add nvme_get_ns helper
nvme: fix controller ioctl through ns_head
bio: limit bio max size
RDMA/rtrs: fix uninitialized symbol 'cnt'
s390: dasd: Mundane spelling fixes
block/rnbd: Remove all likely and unlikely
block/rnbd-clt: Check the return value of the function rtrs_clt_query
block/rnbd: Fix style issues
block/rnbd-clt: Change queue_depth type in rnbd_clt_session to size_t
Pull io_uring fixes from Jens Axboe:
"Mostly fixes for merge window merged code. In detail:
- Error case memory leak fixes (Colin, Zqiang)
- Add the tools/io_uring/ to the list of maintained files (Lukas)
- Set of fixes for the modified buffer registration API (Pavel)
- Sanitize io thread setup on x86 (Stefan)
- Ensure we truncate transfer count for registered buffers (Thadeu)"
* tag 'io_uring-5.13-2021-05-07' of git://git.kernel.dk/linux-block:
x86/process: setup io_threads more like normal user space threads
MAINTAINERS: add io_uring tool to IO_URING
io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers
io_uring: Fix memory leak in io_sqe_buffers_register()
io_uring: Fix premature return from loop and memory leak
io_uring: fix unchecked error in switch_start()
io_uring: allow empty slots for reg buffers
io_uring: add more build check for uapi
io_uring: dont overlap internal and user req flags
io_uring: fix drain with rsrc CQEs
Pull NFS client updates from Trond Myklebust:
"Highlights include:
Stable fixes:
- Add validation of the UDP retrans parameter to prevent shift
out-of-bounds
- Don't discard pNFS layout segments that are marked for return
Bugfixes:
- Fix a NULL dereference crash in xprt_complete_bc_request() when the
NFSv4.1 server misbehaves.
- Fix the handling of NFS READDIR cookie verifiers
- Sundry fixes to ensure attribute revalidation works correctly when
the server does not return post-op attributes.
- nfs4_bitmask_adjust() must not change the server global bitmasks
- Fix major timeout handling in the RPC code.
- NFSv4.2 fallocate() fixes.
- Fix the NFSv4.2 SEEK_HOLE/SEEK_DATA end-of-file handling
- Copy offload attribute revalidation fixes
- Fix an incorrect filehandle size check in the pNFS flexfiles driver
- Fix several RDMA transport setup/teardown races
- Fix several RDMA queue wrapping issues
- Fix a misplaced memory read barrier in sunrpc's call_decode()
Features:
- Micro optimisation of the TCP transmission queue using TCP_CORK
- statx() performance improvements by further splitting up the
tracking of invalid cached file metadata.
- Support the NFSv4.2 'change_attr_type' attribute and use it to
optimise handling of change attribute updates"
* tag 'nfs-for-5.13-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (85 commits)
xprtrdma: Fix a NULL dereference in frwr_unmap_sync()
sunrpc: Fix misplaced barrier in call_decode
NFSv4.2: Remove ifdef CONFIG_NFSD from NFSv4.2 client SSC code.
xprtrdma: Move fr_mr field to struct rpcrdma_mr
xprtrdma: Move the Work Request union to struct rpcrdma_mr
xprtrdma: Move fr_linv_done field to struct rpcrdma_mr
xprtrdma: Move cqe to struct rpcrdma_mr
xprtrdma: Move fr_cid to struct rpcrdma_mr
xprtrdma: Remove the RPC/RDMA QP event handler
xprtrdma: Don't display r_xprt memory addresses in tracepoints
xprtrdma: Add an rpcrdma_mr_completion_class
xprtrdma: Add tracepoints showing FastReg WRs and remote invalidation
xprtrdma: Avoid Send Queue wrapping
xprtrdma: Do not wake RPC consumer on a failed LocalInv
xprtrdma: Do not recycle MR after FastReg/LocalInv flushes
xprtrdma: Clarify use of barrier in frwr_wc_localinv_done()
xprtrdma: Rename frwr_release_mr()
xprtrdma: rpcrdma_mr_pop() already does list_del_init()
xprtrdma: Delete rpcrdma_recv_buffer_put()
xprtrdma: Fix cwnd update ordering
...
Pull more iomap updates from Darrick Wong:
"Remove the now unused 'io_private' field from struct iomap_ioend, for
a modest savings in memory allocation"
* tag 'iomap-5.13-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
iomap: remove unused private field from ioend
Pull more xfs updates from Darrick Wong:
"Except for the timestamp struct renaming patches, everything else in
here are bug fixes:
- Rename the log timestamp struct.
- Remove broken transaction counter debugging that wasn't working
correctly on very old filesystems.
- Various fixes to make pre-lazysbcount filesystems work properly
again.
- Fix a free space accounting problem where we neglected to consider
free space btree blocks that track metadata reservation space when
deciding whether or not to allow caller to reserve space for a
metadata update.
- Fix incorrect pagecache clearing behavior during FUNSHARE ops.
- Don't allow log writes if the data device is readonly"
* tag 'xfs-5.13-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: don't allow log writes if the data device is readonly
xfs: fix xfs_reflink_unshare usage of filemap_write_and_wait_range
xfs: set aside allocation btree blocks from block reservation
xfs: introduce in-core global counter of allocbt blocks
xfs: unconditionally read all AGFs on mounts with perag reservation
xfs: count free space btree blocks when scrubbing pre-lazysbcount fses
xfs: update superblock counters correctly for !lazysbcount
xfs: don't check agf_btreeblks on pre-lazysbcount filesystems
xfs: remove obsolete AGF counter debugging
xfs: rename struct xfs_legacy_ictimestamp
xfs: rename xfs_ictimestamp_t
Commit 339ddb53d3 ("fs/epoll: remove unnecessary wakeups of nested
epoll") changed the userspace visible behavior of exclusive waiters
blocked on a common epoll descriptor upon a single event becoming ready.
Previously, all tasks doing epoll_wait would awake, and now only one is
awoken, potentially causing missed wakeups on applications that rely on
this behavior, such as Apache Qpid.
While the aforementioned commit aims at having only a wakeup single path
in ep_poll_callback (with the exceptions of epoll_ctl cases), we need to
restore the wakeup in what was the old ep_scan_ready_list() such that
the next thread can be awoken, in a cascading style, after the waker's
corresponding ep_send_events().
Link: https://lkml.kernel.org/r/20210405231025.33829-3-dave@stgolabs.net
Fixes: 339ddb53d3 ("fs/epoll: remove unnecessary wakeups of nested epoll")
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Roman Penyaev <rpenyaev@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull ceph updates from Ilya Dryomov:
"Notable items here are
- a series to take advantage of David Howells' netfs helper library
from Jeff
- three new filesystem client metrics from Xiubo
- ceph.dir.rsnaps vxattr from Yanhu
- two auth-related fixes from myself, marked for stable.
Interspersed is a smattering of assorted fixes and cleanups across the
filesystem"
* tag 'ceph-for-5.13-rc1' of git://github.com/ceph/ceph-client: (24 commits)
libceph: allow addrvecs with a single NONE/blank address
libceph: don't set global_id until we get an auth ticket
libceph: bump CephXAuthenticate encoding version
ceph: don't allow access to MDS-private inodes
ceph: fix up some bare fetches of i_size
ceph: convert some PAGE_SIZE invocations to thp_size()
ceph: support getting ceph.dir.rsnaps vxattr
ceph: drop pinned_page parameter from ceph_get_caps
ceph: fix inode leak on getattr error in __fh_to_dentry
ceph: only check pool permissions for regular files
ceph: send opened files/pinned caps/opened inodes metrics to MDS daemon
ceph: avoid counting the same request twice or more
ceph: rename the metric helpers
ceph: fix kerneldoc copypasta over ceph_start_io_direct
ceph: use attach/detach_page_private for tracking snap context
ceph: don't use d_add in ceph_handle_snapdir
ceph: don't clobber i_snap_caps on non-I_NEW inode
ceph: fix fall-through warnings for Clang
ceph: convert ceph_readpages to ceph_readahead
ceph: convert ceph_write_begin to netfs_write_begin
...
Pull ecryptfs updates from Tyler Hicks:
"Code cleanups and a bug fix
- W=1 compiler warning cleanups
- Mutex initialization simplification
- Protect against NULL pointer exception during mount"
* tag 'ecryptfs-5.13-rc1-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
ecryptfs: fix kernel panic with null dev_name
ecryptfs: remove unused helpers
ecryptfs: Fix typo in message
eCryptfs: Use DEFINE_MUTEX() for mutex lock
ecryptfs: keystore: Fix some kernel-doc issues and demote non-conformant headers
ecryptfs: inode: Help out nearly-there header and demote non-conformant ones
ecryptfs: mmap: Help out one function header and demote other abuses
ecryptfs: crypto: Supply some missing param descriptions and demote abuses
ecryptfs: miscdev: File headers are not good kernel-doc candidates
ecryptfs: main: Demote a bunch of non-conformant kernel-doc headers
ecryptfs: messaging: Add missing param descriptions and demote abuses
ecryptfs: super: Fix formatting, naming and kernel-doc abuses
ecryptfs: file: Demote kernel-doc abuses
ecryptfs: kthread: Demote file header and provide description for 'cred'
ecryptfs: dentry: File headers are not good candidates for kernel-doc
ecryptfs: debug: Demote a couple of kernel-doc abuses
ecryptfs: read_write: File headers do not make good candidates for kernel-doc
ecryptfs: use DEFINE_MUTEX() for mutex lock
eCryptfs: add a semicolon
Read and write operations are capped to MAX_RW_COUNT. Some read ops rely on
that limit, and that is not guaranteed by the IORING_OP_PROVIDE_BUFFERS.
Truncate those lengths when doing io_add_buffers, so buffer addresses still
use the uncapped length.
Also, take the chance and change struct io_buffer len member to __u32, so
it matches struct io_provide_buffer len member.
This fixes CVE-2021-3491, also reported as ZDI-CAN-13546.
Fixes: ddf0322db7 ("io_uring: add IORING_OP_PROVIDE_BUFFERS")
Reported-by: Billy Jheng Bing-Jhong (@st424204)
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge more updates from Andrew Morton:
"The remainder of the main mm/ queue.
143 patches.
Subsystems affected by this patch series (all mm): pagecache, hugetlb,
userfaultfd, vmscan, compaction, migration, cma, ksm, vmstat, mmap,
kconfig, util, memory-hotplug, zswap, zsmalloc, highmem, cleanups, and
kfence"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (143 commits)
kfence: use power-efficient work queue to run delayed work
kfence: maximize allocation wait timeout duration
kfence: await for allocation using wait_event
kfence: zero guard page after out-of-bounds access
mm/process_vm_access.c: remove duplicate include
mm/mempool: minor coding style tweaks
mm/highmem.c: fix coding style issue
btrfs: use memzero_page() instead of open coded kmap pattern
iov_iter: lift memzero_page() to highmem.h
mm/zsmalloc: use BUG_ON instead of if condition followed by BUG.
mm/zswap.c: switch from strlcpy to strscpy
arm64/Kconfig: introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
x86/Kconfig: introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
mm,memory_hotplug: add kernel boot option to enable memmap_on_memory
acpi,memhotplug: enable MHP_MEMMAP_ON_MEMORY when supported
mm,memory_hotplug: allocate memmap from the added memory range
mm,memory_hotplug: factor out adjusting present pages into adjust_present_page_count()
mm,memory_hotplug: relax fully spanned sections check
drivers/base/memory: introduce memory_block_{online,offline}
mm/memory_hotplug: remove broken locking of zone PCP structures during hot remove
...
Pull more nfsd updates from Chuck Lever:
"Additional fixes and clean-ups for NFSD since tags/nfsd-5.13,
including a fix to grant read delegations for files open for writing"
* tag 'nfsd-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
SUNRPC: Fix null pointer dereference in svc_rqst_free()
SUNRPC: fix ternary sign expansion bug in tracing
nfsd: Fix fall-through warnings for Clang
nfsd: grant read delegations to clients holding writes
nfsd: reshuffle some code
nfsd: track filehandle aliasing in nfs4_files
nfsd: hash nfs4_files by inode number
nfsd: ensure new clients break delegations
nfsd: removed unused argument in nfsd_startup_generic()
nfsd: remove unused function
svcrdma: Pass a useful error code to the send_err tracepoint
svcrdma: Rename goto labels in svc_rdma_sendto()
svcrdma: Don't leak send_ctxt on Send errors
Pull cifs updates from Steve French:
"Ten CIFS/SMB3 changes - including two marked for stable - including
some important multichannel fixes, as well as support for handle
leases (deferred close) and shutdown support:
- some important multichannel fixes
- support for handle leases (deferred close)
- shutdown support (which is also helpful since it enables multiple
xfstests)
- enable negotiating stronger encryption by default (GCM256)
- improve wireshark debugging by allowing more options for root to
dump decryption keys
SambaXP and the SMB3 Plugfest test event are going on now so I am
expecting more patches over the next few days due to extra testing
(including more multichannel fixes)"
* tag '5.13-rc-smb3-part2' of git://git.samba.org/sfrench/cifs-2.6:
fs/cifs: Fix resource leak
Cifs: Fix kernel oops caused by deferred close for files.
cifs: fix regression when mounting shares with prefix paths
cifs: use echo_interval even when connection not ready.
cifs: detect dead connections only when echoes are enabled.
smb3.1.1: allow dumping keys for multiuser mounts
smb3.1.1: allow dumping GCM256 keys to improve debugging of encrypted shares
cifs: add shutdown support
cifs: Deferred close for files
smb3.1.1: enable negotiating stronger encryption by default
There are many places where kmap/memset/kunmap patterns occur.
Use the newly lifted memzero_page() to eliminate direct uses of kmap and
leverage the new core functions use of kmap_local_page().
The development of this patch was aided by the following coccinelle
script:
// <smpl>
// SPDX-License-Identifier: GPL-2.0-only
// Find kmap/memset/kunmap pattern and replace with memset*page calls
//
// NOTE: Offsets and other expressions may be more complex than what the script
// will automatically generate. Therefore a catchall rule is provided to find
// the pattern which then must be evaluated by hand.
//
// Confidence: Low
// Copyright: (C) 2021 Intel Corporation
// URL: http://coccinelle.lip6.fr/
// Comments:
// Options:
//
// Then the memset pattern
//
@ memset_rule1 @
expression page, V, L, Off;
identifier ptr;
type VP;
@@
(
-VP ptr = kmap(page);
|
-ptr = kmap(page);
|
-VP ptr = kmap_atomic(page);
|
-ptr = kmap_atomic(page);
)
<+...
(
-memset(ptr, 0, L);
+memzero_page(page, 0, L);
|
-memset(ptr + Off, 0, L);
+memzero_page(page, Off, L);
|
-memset(ptr, V, L);
+memset_page(page, V, 0, L);
|
-memset(ptr + Off, V, L);
+memset_page(page, V, Off, L);
)
...+>
(
-kunmap(page);
|
-kunmap_atomic(ptr);
)
// Remove any pointers left unused
@
depends on memset_rule1
@
identifier memset_rule1.ptr;
type VP, VP1;
@@
-VP ptr;
... when != ptr;
? VP1 ptr;
//
// Catch all
//
@ memset_rule2 @
expression page;
identifier ptr;
expression GenTo, GenSize, GenValue;
type VP;
@@
(
-VP ptr = kmap(page);
|
-ptr = kmap(page);
|
-VP ptr = kmap_atomic(page);
|
-ptr = kmap_atomic(page);
)
<+...
(
//
// Some call sites have complex expressions within the memset/memcpy
// The follow are catch alls which need to be evaluated by hand.
//
-memset(GenTo, 0, GenSize);
+memzero_pageExtra(page, GenTo, GenSize);
|
-memset(GenTo, GenValue, GenSize);
+memset_pageExtra(page, GenValue, GenTo, GenSize);
)
...+>
(
-kunmap(page);
|
-kunmap_atomic(ptr);
)
// Remove any pointers left unused
@
depends on memset_rule2
@
identifier memset_rule2.ptr;
type VP, VP1;
@@
-VP ptr;
... when != ptr;
? VP1 ptr;
// </smpl>
Link: https://lkml.kernel.org/r/20210309212137.2610186-4-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pages containing buffer_heads that are in one of the per-CPU buffer_head
LRU caches will be pinned and thus cannot be migrated. This can prevent
CMA allocations from succeeding, which are often used on platforms with
co-processors (such as a DSP) that can only use physically contiguous
memory. It can also prevent memory hot-unplugging from succeeding,
which involves migrating at least MIN_MEMORY_BLOCK_SIZE bytes of memory,
which ranges from 8 MiB to 1 GiB based on the architecture in use.
Correspondingly, invalidate the BH LRU caches before a migration starts
and stop any buffer_head from being cached in the LRU caches, until
migration has finished.
Link: https://lkml.kernel.org/r/20210319175127.886124-3-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Chris Goldsworthy <cgoldswo@codeaurora.org>
Reported-by: Laura Abbott <labbott@kernel.org>
Tested-by: Oliver Sang <oliver.sang@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: John Dias <joaodias@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "userfaultfd: add minor fault handling", v9.
Overview
========
This series adds a new userfaultfd feature, UFFD_FEATURE_MINOR_HUGETLBFS.
When enabled (via the UFFDIO_API ioctl), this feature means that any
hugetlbfs VMAs registered with UFFDIO_REGISTER_MODE_MISSING will *also*
get events for "minor" faults. By "minor" fault, I mean the following
situation:
Let there exist two mappings (i.e., VMAs) to the same page(s) (shared
memory). One of the mappings is registered with userfaultfd (in minor
mode), and the other is not. Via the non-UFFD mapping, the underlying
pages have already been allocated & filled with some contents. The UFFD
mapping has not yet been faulted in; when it is touched for the first
time, this results in what I'm calling a "minor" fault. As a concrete
example, when working with hugetlbfs, we have huge_pte_none(), but
find_lock_page() finds an existing page.
We also add a new ioctl to resolve such faults: UFFDIO_CONTINUE. The idea
is, userspace resolves the fault by either a) doing nothing if the
contents are already correct, or b) updating the underlying contents using
the second, non-UFFD mapping (via memcpy/memset or similar, or something
fancier like RDMA, or etc...). In either case, userspace issues
UFFDIO_CONTINUE to tell the kernel "I have ensured the page contents are
correct, carry on setting up the mapping".
Use Case
========
Consider the use case of VM live migration (e.g. under QEMU/KVM):
1. While a VM is still running, we copy the contents of its memory to a
target machine. The pages are populated on the target by writing to the
non-UFFD mapping, using the setup described above. The VM is still running
(and therefore its memory is likely changing), so this may be repeated
several times, until we decide the target is "up to date enough".
2. We pause the VM on the source, and start executing on the target machine.
During this gap, the VM's user(s) will *see* a pause, so it is desirable to
minimize this window.
3. Between the last time any page was copied from the source to the target, and
when the VM was paused, the contents of that page may have changed - and
therefore the copy we have on the target machine is out of date. Although we
can keep track of which pages are out of date, for VMs with large amounts of
memory, it is "slow" to transfer this information to the target machine. We
want to resume execution before such a transfer would complete.
4. So, the guest begins executing on the target machine. The first time it
touches its memory (via the UFFD-registered mapping), userspace wants to
intercept this fault. Userspace checks whether or not the page is up to date,
and if not, copies the updated page from the source machine, via the non-UFFD
mapping. Finally, whether a copy was performed or not, userspace issues a
UFFDIO_CONTINUE ioctl to tell the kernel "I have ensured the page contents
are correct, carry on setting up the mapping".
We don't have to do all of the final updates on-demand. The userfaultfd manager
can, in the background, also copy over updated pages once it receives the map of
which pages are up-to-date or not.
Interaction with Existing APIs
==============================
Because this is a feature, a registered VMA could potentially receive both
missing and minor faults. I spent some time thinking through how the
existing API interacts with the new feature:
UFFDIO_CONTINUE cannot be used to resolve non-minor faults, as it does not
allocate a new page. If UFFDIO_CONTINUE is used on a non-minor fault:
- For non-shared memory or shmem, -EINVAL is returned.
- For hugetlb, -EFAULT is returned.
UFFDIO_COPY and UFFDIO_ZEROPAGE cannot be used to resolve minor faults.
Without modifications, the existing codepath assumes a new page needs to
be allocated. This is okay, since userspace must have a second
non-UFFD-registered mapping anyway, thus there isn't much reason to want
to use these in any case (just memcpy or memset or similar).
- If UFFDIO_COPY is used on a minor fault, -EEXIST is returned.
- If UFFDIO_ZEROPAGE is used on a minor fault, -EEXIST is returned (or -EINVAL
in the case of hugetlb, as UFFDIO_ZEROPAGE is unsupported in any case).
- UFFDIO_WRITEPROTECT simply doesn't work with shared memory, and returns
-ENOENT in that case (regardless of the kind of fault).
Future Work
===========
This series only supports hugetlbfs. I have a second series in flight to
support shmem as well, extending the functionality. This series is more
mature than the shmem support at this point, and the functionality works
fully on hugetlbfs, so this series can be merged first and then shmem
support will follow.
This patch (of 6):
This feature allows userspace to intercept "minor" faults. By "minor"
faults, I mean the following situation:
Let there exist two mappings (i.e., VMAs) to the same page(s). One of the
mappings is registered with userfaultfd (in minor mode), and the other is
not. Via the non-UFFD mapping, the underlying pages have already been
allocated & filled with some contents. The UFFD mapping has not yet been
faulted in; when it is touched for the first time, this results in what
I'm calling a "minor" fault. As a concrete example, when working with
hugetlbfs, we have huge_pte_none(), but find_lock_page() finds an existing
page.
This commit adds the new registration mode, and sets the relevant flag on
the VMAs being registered. In the hugetlb fault path, if we find that we
have huge_pte_none(), but find_lock_page() does indeed find an existing
page, then we have a "minor" fault, and if the VMA has the userfaultfd
registration flag, we call into userfaultfd to handle it.
This is implemented as a new registration mode, instead of an API feature.
This is because the alternative implementation has significant drawbacks
[1].
However, doing it this was requires we allocate a VM_* flag for the new
registration mode. On 32-bit systems, there are no unused bits, so this
feature is only supported on architectures with
CONFIG_ARCH_USES_HIGH_VMA_FLAGS. When attempting to register a VMA in
MINOR mode on 32-bit architectures, we return -EINVAL.
[1] https://lore.kernel.org/patchwork/patch/1380226/
[peterx@redhat.com: fix minor fault page leak]
Link: https://lkml.kernel.org/r/20210322175132.36659-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20210301222728.176417-1-axelrasmussen@google.com
Link: https://lkml.kernel.org/r/20210301222728.176417-2-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michal Koutn" <mkoutny@suse.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shawn Anastasio <shawn@anastas.io>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Adam Ruprecht <ruprecht@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Cannon Matthews <cannonmatthews@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
clear_inode()'s BUG_ON(!mapping_empty(&inode->i_data)) is unsafe: we
know of two ways in which nodes can and do (on rare occasions) get left
behind. Until those are fixed, do not BUG_ON() nor even WARN_ON().
Yes, this will then leak those nodes (or the next user of the struct
inode may use them); but this has been happening for years, and the new
BUG_ON(!mapping_empty) was only guilty of revealing that. A proper fix
will follow, but no hurry.
Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2104292229380.16080@eggly.anvils
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Remove nrexceptional tracking", v2.
We actually use nrexceptional for very little these days. It's a minor
pain to keep in sync with nrpages, but the pain becomes much bigger with
the THP patches because we don't know how many indices a shadow entry
occupies. It's easier to just remove it than keep it accurate.
Also, we save 8 bytes per inode which is nothing to sneeze at; on my
laptop, it would improve shmem_inode_cache from 22 to 23 objects per
16kB, and inode_cache from 26 to 27 objects. Combined, that saves
a megabyte of memory from a combined usage of 25MB for both caches.
Unfortunately, ext4 doesn't cross a magic boundary, so it doesn't save
any memory for ext4.
This patch (of 4):
Instead of checking the two counters (nrpages and nrexceptional), we can
just check whether i_pages is empty.
Link: https://lkml.kernel.org/r/20201026151849.24232-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20201026151849.24232-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull JFFS2, UBI and UBIFS updates from Richard Weinberger:
"JFFS2:
- Use splice_write()
- Fix for a slab-out-of-bounds bug
UBI:
- Fix for clang related warnings
- Code cleanup
UBIFS:
- Fix for inode rebirth at replay
- Set s_uuid
- Use zstd for default filesystem"
* tag 'for-linus-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
ubi: Remove unnecessary struct declaration
jffs2: Hook up splice_write callback
jffs2: avoid Wempty-body warnings
jffs2: Fix kasan slab-out-of-bounds problem
ubi: Fix fall-through warnings for Clang
ubifs: Report max LEB count at mount time
ubifs: Set s_uuid in super block to support ima/evm uuid options
ubifs: Default to zstd compression
ubifs: Only check replay with inode type to judge if inode linked
Pull f2fs updates from Jaegeuk Kim:
"In this round, we added a new mount option, "checkpoint_merge", which
introduces a kernel thread dealing with the f2fs checkpoints. Once we
start to manage the IO priority along with blk-cgroup, the checkpoint
operation can be processed in a lower priority under the process
context. Since the checkpoint holds all the filesystem operations, we
give a higher priority to the checkpoint thread all the time.
Enhancements:
- introduce gc_merge mount option to introduce a checkpoint thread
- improve to run discard thread efficiently
- allow modular compression algorithms
- expose # of overprivision segments to sysfs
- expose runtime compression stat to sysfs
Bug fixes:
- fix OOB memory access by the node id lookup
- avoid touching checkpointed data in the checkpoint-disabled mode
- fix the resizing flow to avoid kernel panic and race conditions
- fix block allocation issues on pinned files
- address some swapfile issues
- fix hugtask problem and kernel panic during atomic write operations
- don't start checkpoint thread in RO
And, we've cleaned up some kernel coding style and build warnings. In
addition, we fixed some minor race conditions and error handling
routines"
* tag 'f2fs-for-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (48 commits)
f2fs: drop inplace IO if fs status is abnormal
f2fs: compress: remove unneed check condition
f2fs: clean up left deprecated IO trace codes
f2fs: avoid using native allocate_segment_by_default()
f2fs: remove unnecessary struct declaration
f2fs: fix to avoid NULL pointer dereference
f2fs: avoid duplicated codes for cleanup
f2fs: document: add description about compressed space handling
f2fs: clean up build warnings
f2fs: fix the periodic wakeups of discard thread
f2fs: fix to avoid accessing invalid fio in f2fs_allocate_data_block()
f2fs: fix to avoid GC/mmap race with f2fs_truncate()
f2fs: set checkpoint_merge by default
f2fs: Fix a hungtask problem in atomic write
f2fs: fix to restrict mount condition on readonly block device
f2fs: introduce gc_merge mount option
f2fs: fix to cover __allocate_new_section() with curseg_lock
f2fs: fix wrong alloc_type in f2fs_do_replace_block
f2fs: delete empty compress.h
f2fs: fix a typo in inode.c
...
Pull m68knommu updates from Greg Ungerer:
- a fix for interrupt number range checking for the ColdFire SIMR
interrupt controller.
- changes for the binfmt_flat binary loader to allow RISC-V nommu
support it needs to be able to accept flat binaries that have no gap
between the text and data sections.
* tag 'm68knommu-for-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
m68k: coldfire: fix irq ranges
riscv: Disable data start offset in flat binaries
binfmt_flat: allow not offsetting data start
The -EIO error return path is leaking memory allocated
to page. Fix this by moving the allocation block after
the check of cifs_forced_shutdown.
Addresses-Coverity: ("Resource leak")
Fixes: 087f757b01 ("cifs: add shutdown support")
Signed-off-by: Khaled ROMDHANI <khaledromdhani216@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The commit 315db9a05b ("cifs: fix leak in cifs_smb3_do_mount() ctx")
revealed an existing bug when mounting shares that contain a prefix
path or DFS links.
cifs_setup_volume_info() requires the @devname to contain the full
path (UNC + prefix) to update the fs context with the new UNC and
prepath values, however we were passing only the UNC
path (old_ctx->UNC) in @device thus discarding any prefix paths.
Instead of concatenating both old_ctx->{UNC,prepath} and pass it in
@devname, just keep the dup'ed values of UNC and prepath in
cifs_sb->ctx after calling smb3_fs_context_dup(), and fix
smb3_parse_devname() to correctly parse and not leak the new UNC and
prefix paths.
Cc: <stable@vger.kernel.org> # v5.11+
Fixes: 315db9a05b ("cifs: fix leak in cifs_smb3_do_mount() ctx")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Acked-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
The only remaining user of ->io_private is the generic ioend merging
infrastructure. The only user of that is XFS, which no longer sets
->io_private or passes an associated merge callback. Remove the
unused parameter and the ->io_private field.
CC: linux-fsdevel@vger.kernel.org
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
While running generic/050 with an external log, I observed this warning
in dmesg:
Trying to write to read-only block-device sda4 (partno 4)
WARNING: CPU: 2 PID: 215677 at block/blk-core.c:704 submit_bio_checks+0x256/0x510
Call Trace:
submit_bio_noacct+0x2c/0x430
_xfs_buf_ioapply+0x283/0x3c0 [xfs]
__xfs_buf_submit+0x6a/0x210 [xfs]
xfs_buf_delwri_submit_buffers+0xf8/0x270 [xfs]
xfsaild+0x2db/0xc50 [xfs]
kthread+0x14b/0x170
I think this happened because we tried to cover the log after a readonly
mount, and the AIL tried to write the primary superblock to the data
device. The test marks the data device readonly, but it doesn't do the
same to the external log device. Therefore, XFS thinks that the log is
writable, even though AIL writes whine to dmesg because the data device
is read only.
Fix this by amending xfs_log_writable to prevent writes when the AIL
can't possible write anything into the filesystem.
Note: As for the external log or the rt devices being readonly--
xfs_blkdev_get will complain about that if we aren't doing a norecovery
mount.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Pull tracing updates from Steven Rostedt:
"New feature:
- A new "func-no-repeats" option in tracefs/options directory.
When set the function tracer will detect if the current function
being traced is the same as the previous one, and instead of
recording it, it will keep track of the number of times that the
function is repeated in a row. And when another function is
recorded, it will write a new event that shows the function that
repeated, the number of times it repeated and the time stamp of
when the last repeated function occurred.
Enhancements:
- In order to implement the above "func-no-repeats" option, the ring
buffer timestamp can now give the accurate timestamp of the event
as it is being recorded, instead of having to record an absolute
timestamp for all events. This helps the histogram code which no
longer needs to waste ring buffer space.
- New validation logic to make sure all trace events that access
dereferenced pointers do so in a safe way, and will warn otherwise.
Fixes:
- No longer limit the PIDs of tasks that are recorded for
"saved_cmdlines" to PID_MAX_DEFAULT (32768), as systemd now allows
for a much larger range. This caused the mapping of PIDs to the
task names to be dropped for all tasks with a PID greater than
32768.
- Change trace_clock_global() to never block. This caused a deadlock.
Clean ups:
- Typos, prototype fixes, and removing of duplicate or unused code.
- Better management of ftrace_page allocations"
* tag 'trace-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (32 commits)
tracing: Restructure trace_clock_global() to never block
tracing: Map all PIDs to command lines
ftrace: Reuse the output of the function tracer for func_repeats
tracing: Add "func_no_repeats" option for function tracing
tracing: Unify the logic for function tracing options
tracing: Add method for recording "func_repeats" events
tracing: Add "last_func_repeats" to struct trace_array
tracing: Define new ftrace event "func_repeats"
tracing: Define static void trace_print_time()
ftrace: Simplify the calculation of page number for ftrace_page->records some more
ftrace: Store the order of pages allocated in ftrace_page
tracing: Remove unused argument from "ring_buffer_time_stamp()
tracing: Remove duplicate struct declaration in trace_events.h
tracing: Update create_system_filter() kernel-doc comment
tracing: A minor cleanup for create_system_filter()
kernel: trace: Mundane typo fixes in the file trace_events_filter.c
tracing: Fix various typos in comments
scripts/recordmcount.pl: Make vim and emacs indent the same
scripts/recordmcount.pl: Make indent spacing consistent
tracing: Add a verifier to check string pointers for trace events
...
Pull receive_fd update from Al Viro:
"Cleanup of receive_fd mess"
* 'work.file' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: split receive_fd_replace from __receive_fd
