Pull nfsd fixes from Chuck Lever:: - Revert one v6.13 fix at the author's request (to be done differently) - Fix a minor problem with recent NFSv4.2 COPY enhancements - Fix an NFSv4.0 callback bug introduced in the v6.13 merge window * tag 'nfsd-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: nfsd: restore callback functionality for NFSv4.0 NFSD: fix management of pending async copies nfsd: Revert "nfsd: release svc_expkey/svc_export with rcu_work"
A recent patch inadvertently broke callbacks for NFSv4.0.
In the 4.0 case we do not expect a session to be found but still need to
call setup_callback_client() which will not try to dereference it.
This patch moves the check for failure to find a session into the 4.1+
branch of setup_callback_client()
Fixes: 1e02c641c3a4 ("NFSD: Prevent NULL dereference in nfsd4_process_cb_update()")
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently the pending_async_copies count is decremented just
before a struct nfsd4_copy is destroyed. After commit aa0ebd21df9c
("NFSD: Add nfsd4_copy time-to-live") nfsd4_copy structures sticks
around for 10 lease periods after the COPY itself has completed,
the pending_async_copies count stays high for a long time. This
causes NFSD to avoid the use of background copy even though the
actual background copy workload might no longer be running.
In this patch, decrement pending_async_copies once async copy thread
is done processing the copy work.
Fixes: aa0ebd21df9c ("NFSD: Add nfsd4_copy time-to-live")
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This reverts commit f8c989a0c89a75d30f899a7cabdc14d72522bb8d.
Before this commit, svc_export_put or expkey_put will call path_put with
sync mode. After this commit, path_put will be called with async mode.
And this can lead the unexpected results show as follow.
mkfs.xfs -f /dev/sda
echo "/ *(rw,no_root_squash,fsid=0)" > /etc/exports
echo "/mnt *(rw,no_root_squash,fsid=1)" >> /etc/exports
exportfs -ra
service nfs-server start
mount -t nfs -o vers=4.0 127.0.0.1:/mnt /mnt1
mount /dev/sda /mnt/sda
touch /mnt1/sda/file
exportfs -r
umount /mnt/sda # failed unexcepted
The touch will finally call nfsd_cross_mnt, add refcount to mount, and
then add cache_head. Before this commit, exportfs -r will call
cache_flush to cleanup all cache_head, and path_put in
svc_export_put/expkey_put will be finished with sync mode. So, the
latter umount will always success. However, after this commit, path_put
will be called with async mode, the latter umount may failed, and if
we add some delay, umount will success too. Personally I think this bug
and should be fixed. We first revert before bugfix patch, and then fix
the original bug with a different way.
Fixes: f8c989a0c89a ("nfsd: release svc_expkey/svc_export with rcu_work")
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Pull nfsd updates from Chuck Lever: "Jeff Layton contributed a scalability improvement to NFSD's NFSv4 backchannel session implementation. This improvement is intended to increase the rate at which NFSD can safely recall NFSv4 delegations from clients, to avoid the need to revoke them. Revoking requires a slow state recovery process. A wide variety of bug fixes and other incremental improvements make up the bulk of commits in this series. As always I am grateful to the NFSD contributors, reviewers, testers, and bug reporters who participated during this cycle" * tag 'nfsd-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (72 commits) nfsd: allow for up to 32 callback session slots nfs_common: must not hold RCU while calling nfsd_file_put_local nfsd: get rid of include ../internal.h nfsd: fix nfs4_openowner leak when concurrent nfsd4_open occur NFSD: Add nfsd4_copy time-to-live NFSD: Add a laundromat reaper for async copy state NFSD: Block DESTROY_CLIENTID only when there are ongoing async COPY operations NFSD: Handle an NFS4ERR_DELAY response to CB_OFFLOAD NFSD: Free async copy information in nfsd4_cb_offload_release() NFSD: Fix nfsd4_shutdown_copy() NFSD: Add a tracepoint to record canceled async COPY operations nfsd: make nfsd4_session->se_flags a bool nfsd: remove nfsd4_session->se_bchannel nfsd: make use of warning provided by refcount_t nfsd: Don't fail OP_SETCLIENTID when there are too many clients. svcrdma: fix miss destroy percpu_counter in svc_rdma_proc_init() xdrgen: Remove program_stat_to_errno() call sites xdrgen: Update the files included in client-side source code xdrgen: Remove check for "nfs_ok" in C templates xdrgen: Remove tracepoint call site ...
Pull MM updates from Andrew Morton:
- The series "zram: optimal post-processing target selection" from
Sergey Senozhatsky improves zram's post-processing selection
algorithm. This leads to improved memory savings.
- Wei Yang has gone to town on the mapletree code, contributing several
series which clean up the implementation:
- "refine mas_mab_cp()"
- "Reduce the space to be cleared for maple_big_node"
- "maple_tree: simplify mas_push_node()"
- "Following cleanup after introduce mas_wr_store_type()"
- "refine storing null"
- The series "selftests/mm: hugetlb_fault_after_madv improvements" from
David Hildenbrand fixes this selftest for s390.
- The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
implements some rationaizations and cleanups in the page mapping
code.
- The series "mm: optimize shadow entries removal" from Shakeel Butt
optimizes the file truncation code by speeding up the handling of
shadow entries.
- The series "Remove PageKsm()" from Matthew Wilcox completes the
migration of this flag over to being a folio-based flag.
- The series "Unify hugetlb into arch_get_unmapped_area functions" from
Oscar Salvador implements a bunch of consolidations and cleanups in
the hugetlb code.
- The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
takes away the wp-fault time practice of turning a huge zero page
into small pages. Instead we replace the whole thing with a THP. More
consistent cleaner and potentiall saves a large number of pagefaults.
- The series "percpu: Add a test case and fix for clang" from Andy
Shevchenko enhances and fixes the kernel's built in percpu test code.
- The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
optimizes mremap() by avoiding doing things which we didn't need to
do.
- The series "Improve the tmpfs large folio read performance" from
Baolin Wang teaches tmpfs to copy data into userspace at the folio
size rather than as individual pages. A 20% speedup was observed.
- The series "mm/damon/vaddr: Fix issue in
damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
splitting.
- The series "memcg-v1: fully deprecate charge moving" from Shakeel
Butt removes the long-deprecated memcgv2 charge moving feature.
- The series "fix error handling in mmap_region() and refactor" from
Lorenzo Stoakes cleanup up some of the mmap() error handling and
addresses some potential performance issues.
- The series "x86/module: use large ROX pages for text allocations"
from Mike Rapoport teaches x86 to use large pages for
read-only-execute module text.
- The series "page allocation tag compression" from Suren Baghdasaryan
is followon maintenance work for the new page allocation profiling
feature.
- The series "page->index removals in mm" from Matthew Wilcox remove
most references to page->index in mm/. A slow march towards shrinking
struct page.
- The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
interface tests" from Andrew Paniakin performs maintenance work for
DAMON's self testing code.
- The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
improves zswap's batching of compression and decompression. It is a
step along the way towards using Intel IAA hardware acceleration for
this zswap operation.
- The series "kasan: migrate the last module test to kunit" from
Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
tests over to the KUnit framework.
- The series "implement lightweight guard pages" from Lorenzo Stoakes
permits userapace to place fault-generating guard pages within a
single VMA, rather than requiring that multiple VMAs be created for
this. Improved efficiencies for userspace memory allocators are
expected.
- The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
tracepoints to provide increased visibility into memcg stats flushing
activity.
- The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
fixes a zram buglet which potentially affected performance.
- The series "mm: add more kernel parameters to control mTHP" from
Maíra Canal enhances our ability to control/configuremultisize THP
from the kernel boot command line.
- The series "kasan: few improvements on kunit tests" from Sabyrzhan
Tasbolatov has a couple of fixups for the KASAN KUnit tests.
- The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
from Kairui Song optimizes list_lru memory utilization when lockdep
is enabled.
* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
mm/kfence: add a new kunit test test_use_after_free_read_nofault()
zram: fix NULL pointer in comp_algorithm_show()
memcg/hugetlb: add hugeTLB counters to memcg
vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
zram: ZRAM_DEF_COMP should depend on ZRAM
MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
Docs/mm/damon: recommend academic papers to read and/or cite
mm: define general function pXd_init()
kmemleak: iommu/iova: fix transient kmemleak false positive
mm/list_lru: simplify the list_lru walk callback function
mm/list_lru: split the lock to per-cgroup scope
mm/list_lru: simplify reparenting and initial allocation
mm/list_lru: code clean up for reparenting
mm/list_lru: don't export list_lru_add
mm/list_lru: don't pass unnecessary key parameters
kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
...
nfsd currently only uses a single slot in the callback channel, which is proving to be a bottleneck in some cases. Widen the callback channel to a max of 32 slots (subject to the client's target_maxreqs value). Change the cb_holds_slot boolean to an integer that tracks the current slot number (with -1 meaning "unassigned"). Move the callback slot tracking info into the session. Add a new u32 that acts as a bitmap to track which slots are in use, and a u32 to track the latest callback target_slotid that the client reports. To protect the new fields, add a new per-session spinlock (the se_lock). Fix nfsd41_cb_get_slot to always search for the lowest slotid (using ffs()). Finally, convert the session->se_cb_seq_nr field into an array of ints and add the necessary handling to ensure that the seqids get reset when the slot table grows after shrinking. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Move holding the RCU from nfs_to_nfsd_file_put_local to
nfs_to_nfsd_net_put. It is the call to nfs_to->nfsd_serv_put that
requires the RCU anyway (the puts for nfsd_file and netns were
combined to avoid an extra indirect reference but that
micro-optimization isn't possible now).
This fixes xfstests generic/013 and it triggering:
"Voluntary context switch within RCU read-side critical section!"
[ 143.545738] Call Trace:
[ 143.546206] <TASK>
[ 143.546625] ? show_regs+0x6d/0x80
[ 143.547267] ? __warn+0x91/0x140
[ 143.547951] ? rcu_note_context_switch+0x496/0x5d0
[ 143.548856] ? report_bug+0x193/0x1a0
[ 143.549557] ? handle_bug+0x63/0xa0
[ 143.550214] ? exc_invalid_op+0x1d/0x80
[ 143.550938] ? asm_exc_invalid_op+0x1f/0x30
[ 143.551736] ? rcu_note_context_switch+0x496/0x5d0
[ 143.552634] ? wakeup_preempt+0x62/0x70
[ 143.553358] __schedule+0xaa/0x1380
[ 143.554025] ? _raw_spin_unlock_irqrestore+0x12/0x40
[ 143.554958] ? try_to_wake_up+0x1fe/0x6b0
[ 143.555715] ? wake_up_process+0x19/0x20
[ 143.556452] schedule+0x2e/0x120
[ 143.557066] schedule_preempt_disabled+0x19/0x30
[ 143.557933] rwsem_down_read_slowpath+0x24d/0x4a0
[ 143.558818] ? xfs_efi_item_format+0x50/0xc0 [xfs]
[ 143.559894] down_read+0x4e/0xb0
[ 143.560519] xlog_cil_commit+0x1b2/0xbc0 [xfs]
[ 143.561460] ? _raw_spin_unlock+0x12/0x30
[ 143.562212] ? xfs_inode_item_precommit+0xc7/0x220 [xfs]
[ 143.563309] ? xfs_trans_run_precommits+0x69/0xd0 [xfs]
[ 143.564394] __xfs_trans_commit+0xb5/0x330 [xfs]
[ 143.565367] xfs_trans_roll+0x48/0xc0 [xfs]
[ 143.566262] xfs_defer_trans_roll+0x57/0x100 [xfs]
[ 143.567278] xfs_defer_finish_noroll+0x27a/0x490 [xfs]
[ 143.568342] xfs_defer_finish+0x1a/0x80 [xfs]
[ 143.569267] xfs_bunmapi_range+0x4d/0xb0 [xfs]
[ 143.570208] xfs_itruncate_extents_flags+0x13d/0x230 [xfs]
[ 143.571353] xfs_free_eofblocks+0x12e/0x190 [xfs]
[ 143.572359] xfs_file_release+0x12d/0x140 [xfs]
[ 143.573324] __fput+0xe8/0x2d0
[ 143.573922] __fput_sync+0x1d/0x30
[ 143.574574] nfsd_filp_close+0x33/0x60 [nfsd]
[ 143.575430] nfsd_file_free+0x96/0x150 [nfsd]
[ 143.576274] nfsd_file_put+0xf7/0x1a0 [nfsd]
[ 143.577104] nfsd_file_put_local+0x18/0x30 [nfsd]
[ 143.578070] nfs_close_local_fh+0x101/0x110 [nfs_localio]
[ 143.579079] __put_nfs_open_context+0xc9/0x180 [nfs]
[ 143.580031] nfs_file_clear_open_context+0x4a/0x60 [nfs]
[ 143.581038] nfs_file_release+0x3e/0x60 [nfs]
[ 143.581879] __fput+0xe8/0x2d0
[ 143.582464] __fput_sync+0x1d/0x30
[ 143.583108] __x64_sys_close+0x41/0x80
[ 143.583823] x64_sys_call+0x189a/0x20d0
[ 143.584552] do_syscall_64+0x64/0x170
[ 143.585240] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 143.586185] RIP: 0033:0x7f3c5153efd7
Fixes: 65f2a5c36635 ("nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
added back in 2015 for the sake of vfs_clone_file_range(), which is in linux/fs.h these days Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The action force umount(umount -f) will attempt to kill all rpc_task even
umount operation may ultimately fail if some files remain open.
Consequently, if an action attempts to open a file, it can potentially
send two rpc_task to nfs server.
NFS CLIENT
thread1 thread2
open("file")
...
nfs4_do_open
_nfs4_do_open
_nfs4_open_and_get_state
_nfs4_proc_open
nfs4_run_open_task
/* rpc_task1 */
rpc_run_task
rpc_wait_for_completion_task
umount -f
nfs_umount_begin
rpc_killall_tasks
rpc_signal_task
rpc_task1 been wakeup
and return -512
_nfs4_do_open // while loop
...
nfs4_run_open_task
/* rpc_task2 */
rpc_run_task
rpc_wait_for_completion_task
While processing an open request, nfsd will first attempt to find or
allocate an nfs4_openowner. If it finds an nfs4_openowner that is not
marked as NFS4_OO_CONFIRMED, this nfs4_openowner will released. Since
two rpc_task can attempt to open the same file simultaneously from the
client to server, and because two instances of nfsd can run
concurrently, this situation can lead to lots of memory leak.
Additionally, when we echo 0 to /proc/fs/nfsd/threads, warning will be
triggered.
NFS SERVER
nfsd1 nfsd2 echo 0 > /proc/fs/nfsd/threads
nfsd4_open
nfsd4_process_open1
find_or_alloc_open_stateowner
// alloc oo1, stateid1
nfsd4_open
nfsd4_process_open1
find_or_alloc_open_stateowner
// find oo1, without NFS4_OO_CONFIRMED
release_openowner
unhash_openowner_locked
list_del_init(&oo->oo_perclient)
// cannot find this oo
// from client, LEAK!!!
alloc_stateowner // alloc oo2
nfsd4_process_open2
init_open_stateid
// associate oo1
// with stateid1, stateid1 LEAK!!!
nfs4_get_vfs_file
// alloc nfsd_file1 and nfsd_file_mark1
// all LEAK!!!
nfsd4_process_open2
...
write_threads
...
nfsd_destroy_serv
nfsd_shutdown_net
nfs4_state_shutdown_net
nfs4_state_destroy_net
destroy_client
__destroy_client
// won't find oo1!!!
nfsd_shutdown_generic
nfsd_file_cache_shutdown
kmem_cache_destroy
for nfsd_file_slab
and nfsd_file_mark_slab
// bark since nfsd_file1
// and nfsd_file_mark1
// still alive
=======================================================================
BUG nfsd_file (Not tainted): Objects remaining in nfsd_file on
__kmem_cache_shutdown()
-----------------------------------------------------------------------
Slab 0xffd4000004438a80 objects=34 used=1 fp=0xff11000110e2ad28
flags=0x17ffffc0000240(workingset|head|node=0|zone=2|lastcpupid=0x1fffff)
CPU: 4 UID: 0 PID: 757 Comm: sh Not tainted 6.12.0-rc6+ #19
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x53/0x70
slab_err+0xb0/0xf0
__kmem_cache_shutdown+0x15c/0x310
kmem_cache_destroy+0x66/0x160
nfsd_file_cache_shutdown+0xac/0x210 [nfsd]
nfsd_destroy_serv+0x251/0x2a0 [nfsd]
nfsd_svc+0x125/0x1e0 [nfsd]
write_threads+0x16a/0x2a0 [nfsd]
nfsctl_transaction_write+0x74/0xa0 [nfsd]
vfs_write+0x1ae/0x6d0
ksys_write+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Disabling lock debugging due to kernel taint
Object 0xff11000110e2ac38 @offset=3128
Allocated in nfsd_file_do_acquire+0x20f/0xa30 [nfsd] age=1635 cpu=3
pid=800
nfsd_file_do_acquire+0x20f/0xa30 [nfsd]
nfsd_file_acquire_opened+0x5f/0x90 [nfsd]
nfs4_get_vfs_file+0x4c9/0x570 [nfsd]
nfsd4_process_open2+0x713/0x1070 [nfsd]
nfsd4_open+0x74b/0x8b0 [nfsd]
nfsd4_proc_compound+0x70b/0xc20 [nfsd]
nfsd_dispatch+0x1b4/0x3a0 [nfsd]
svc_process_common+0x5b8/0xc50 [sunrpc]
svc_process+0x2ab/0x3b0 [sunrpc]
svc_handle_xprt+0x681/0xa20 [sunrpc]
nfsd+0x183/0x220 [nfsd]
kthread+0x199/0x1e0
ret_from_fork+0x31/0x60
ret_from_fork_asm+0x1a/0x30
Add nfs4_openowner_unhashed to help found unhashed nfs4_openowner, and
break nfsd4_open process to fix this problem.
Cc: stable@vger.kernel.org # v5.4+
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>