Commit Graph

3588 Commits

Author SHA1 Message Date
Dai Ngo
f385f7d244 NFSD: register/unregister of nfsd-client shrinker at nfsd startup/shutdown time
Currently the nfsd-client shrinker is registered and unregistered at
the time the nfsd module is loaded and unloaded. The problem with this
is the shrinker is being registered before all of the relevant fields
in nfsd_net are initialized when nfsd is started. This can lead to an
oops when memory is low and the shrinker is called while nfsd is not
running.

This patch moves the  register/unregister of nfsd-client shrinker from
module load/unload time to nfsd startup/shutdown time.

Fixes: 44df6f439a ("NFSD: add delegation reaper to react to low memory condition")
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-01-11 21:32:05 -05:00
Xingyuan Mo
e6cf91b7b4 NFSD: fix use-after-free in nfsd4_ssc_setup_dul()
If signal_pending() returns true, schedule_timeout() will not be executed,
causing the waiting task to remain in the wait queue.
Fixed by adding a call to finish_wait(), which ensures that the waiting
task will always be removed from the wait queue.

Fixes: f4e44b3933 ("NFSD: delay unmount source's export after inter-server copy completed.")
Signed-off-by: Xingyuan Mo <hdthky0@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-01-11 21:29:11 -05:00
Chuck Lever
5304930dba NFSD: Use set_bit(RQ_DROPME)
The premise that "Once an svc thread is scheduled and executing an
RPC, no other processes will touch svc_rqst::rq_flags" is false.
svc_xprt_enqueue() examines the RQ_BUSY flag in scheduled nfsd
threads when determining which thread to wake up next.

Fixes: 9315564747 ("NFSD: Use only RQ_DROPME to signal the need to drop a reply")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-01-07 10:16:33 -05:00
Chuck Lever
7827c81f02 Revert "SUNRPC: Use RMW bitops in single-threaded hot paths"
The premise that "Once an svc thread is scheduled and executing an
RPC, no other processes will touch svc_rqst::rq_flags" is false.
svc_xprt_enqueue() examines the RQ_BUSY flag in scheduled nfsd
threads when determining which thread to wake up next.

Found via KCSAN.

Fixes: 28df098881 ("SUNRPC: Use RMW bitops in single-threaded hot paths")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-01-06 13:17:12 -05:00
Jeff Layton
0b3a551fa5 nfsd: fix handling of cached open files in nfsd4_open codepath
Commit fb70bf124b ("NFSD: Instantiate a struct file when creating a
regular NFSv4 file") added the ability to cache an open fd over a
compound. There are a couple of problems with the way this currently
works:

It's racy, as a newly-created nfsd_file can end up with its PENDING bit
cleared while the nf is hashed, and the nf_file pointer is still zeroed
out. Other tasks can find it in this state and they expect to see a
valid nf_file, and can oops if nf_file is NULL.

Also, there is no guarantee that we'll end up creating a new nfsd_file
if one is already in the hash. If an extant entry is in the hash with a
valid nf_file, nfs4_get_vfs_file will clobber its nf_file pointer with
the value of op_file and the old nf_file will leak.

Fix both issues by making a new nfsd_file_acquirei_opened variant that
takes an optional file pointer. If one is present when this is called,
we'll take a new reference to it instead of trying to open the file. If
the nfsd_file already has a valid nf_file, we'll just ignore the
optional file and pass the nfsd_file back as-is.

Also rework the tracepoints a bit to allow for an "opened" variant and
don't try to avoid counting acquisitions in the case where we already
have a cached open file.

Fixes: fb70bf124b ("NFSD: Instantiate a struct file when creating a regular NFSv4 file")
Cc: Trond Myklebust <trondmy@hammerspace.com>
Reported-by: Stanislav Saner <ssaner@redhat.com>
Reported-and-Tested-by: Ruben Vestergaard <rubenv@drcmr.dk>
Reported-and-Tested-by: Torkil Svensgaard <torkil@drcmr.dk>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-01-06 13:17:06 -05:00
Jeff Layton
cad853374d nfsd: fix handling of readdir in v4root vs. mount upcall timeout
If v4 READDIR operation hits a mountpoint and gets back an error,
then it will include that entry in the reply and set RDATTR_ERROR for it
to the error.

That's fine for "normal" exported filesystems, but on the v4root, we
need to be more careful to only expose the existence of dentries that
lead to exports.

If the mountd upcall times out while checking to see whether a
mountpoint on the v4root is exported, then we have no recourse other
than to fail the whole operation.

Cc: Steve Dickson <steved@redhat.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216777
Reported-by: JianHong Yin <yin-jianhong@163.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@vger.kernel.org>
2023-01-02 10:45:31 -05:00
Jeff Layton
789e1e10f2 nfsd: shut down the NFSv4 state objects before the filecache
Currently, we shut down the filecache before trying to clean up the
stateids that depend on it. This leads to the kernel trying to free an
nfsd_file twice, and a refcount overput on the nf_mark.

Change the shutdown procedure to tear down all of the stateids prior
to shutting down the filecache.

Reported-and-tested-by: Wang Yugui <wangyugui@e16-tech.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Fixes: 5e113224c1 ("nfsd: nfsd_file cache entries should be per net namespace")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-22 10:12:56 -05:00
Dai Ngo
75333d48f9 NFSD: fix use-after-free in __nfs42_ssc_open()
Problem caused by source's vfsmount being unmounted but remains
on the delayed unmount list. This happens when nfs42_ssc_open()
return errors.

Fixed by removing nfsd4_interssc_connect(), leave the vfsmount
for the laundromat to unmount when idle time expires.

We don't need to call nfs_do_sb_deactive when nfs42_ssc_open
return errors since the file was not opened so nfs_server->active
was not incremented. Same as in nfsd4_copy, if we fail to
launch nfsd4_do_async_copy thread then there's no need to
call nfs_do_sb_deactive

Reported-by: Xingyuan Mo <hdthky0@gmail.com>
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Tested-by: Xingyuan Mo <hdthky0@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-14 10:11:54 -05:00
Dan Aloni
3bc8edc98b nfsd: under NFSv4.1, fix double svc_xprt_put on rpc_create failure
On error situation `clp->cl_cb_conn.cb_xprt` should not be given
a reference to the xprt otherwise both client cleanup and the
error handling path of the caller call to put it. Better to
delay handing over the reference to a later branch.

[   72.530665] refcount_t: underflow; use-after-free.
[   72.531933] WARNING: CPU: 0 PID: 173 at lib/refcount.c:28 refcount_warn_saturate+0xcf/0x120
[   72.533075] Modules linked in: nfsd(OE) nfsv4(OE) nfsv3(OE) nfs(OE) lockd(OE) compat_nfs_ssc(OE) nfs_acl(OE) rpcsec_gss_krb5(OE) auth_rpcgss(OE) rpcrdma(OE) dns_resolver fscache netfs grace rdma_cm iw_cm ib_cm sunrpc(OE) mlx5_ib mlx5_core mlxfw pci_hyperv_intf ib_uverbs ib_core xt_MASQUERADE nf_conntrack_netlink nft_counter xt_addrtype nft_compat br_netfilter bridge stp llc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set overlay nf_tables nfnetlink crct10dif_pclmul crc32_pclmul ghash_clmulni_intel xfs serio_raw virtio_net virtio_blk net_failover failover fuse [last unloaded: sunrpc]
[   72.540389] CPU: 0 PID: 173 Comm: kworker/u16:5 Tainted: G           OE     5.15.82-dan #1
[   72.541511] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.16.0-3.module+el8.7.0+1084+97b81f61 04/01/2014
[   72.542717] Workqueue: nfsd4_callbacks nfsd4_run_cb_work [nfsd]
[   72.543575] RIP: 0010:refcount_warn_saturate+0xcf/0x120
[   72.544299] Code: 55 00 0f 0b 5d e9 01 50 98 00 80 3d 75 9e 39 08 00 0f 85 74 ff ff ff 48 c7 c7 e8 d1 60 8e c6 05 61 9e 39 08 01 e8 f6 51 55 00 <0f> 0b 5d e9 d9 4f 98 00 80 3d 4b 9e 39 08 00 0f 85 4c ff ff ff 48
[   72.546666] RSP: 0018:ffffb3f841157cf0 EFLAGS: 00010286
[   72.547393] RAX: 0000000000000026 RBX: ffff89ac6231d478 RCX: 0000000000000000
[   72.548324] RDX: ffff89adb7c2c2c0 RSI: ffff89adb7c205c0 RDI: ffff89adb7c205c0
[   72.549271] RBP: ffffb3f841157cf0 R08: 0000000000000000 R09: c0000000ffefffff
[   72.550209] R10: 0000000000000001 R11: ffffb3f841157ad0 R12: ffff89ac6231d180
[   72.551142] R13: ffff89ac6231d478 R14: ffff89ac40c06180 R15: ffff89ac6231d4b0
[   72.552089] FS:  0000000000000000(0000) GS:ffff89adb7c00000(0000) knlGS:0000000000000000
[   72.553175] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   72.553934] CR2: 0000563a310506a8 CR3: 0000000109a66000 CR4: 0000000000350ef0
[   72.554874] Call Trace:
[   72.555278]  <TASK>
[   72.555614]  svc_xprt_put+0xaf/0xe0 [sunrpc]
[   72.556276]  nfsd4_process_cb_update.isra.11+0xb7/0x410 [nfsd]
[   72.557087]  ? update_load_avg+0x82/0x610
[   72.557652]  ? cpuacct_charge+0x60/0x70
[   72.558212]  ? dequeue_entity+0xdb/0x3e0
[   72.558765]  ? queued_spin_unlock+0x9/0x20
[   72.559358]  nfsd4_run_cb_work+0xfc/0x270 [nfsd]
[   72.560031]  process_one_work+0x1df/0x390
[   72.560600]  worker_thread+0x37/0x3b0
[   72.561644]  ? process_one_work+0x390/0x390
[   72.562247]  kthread+0x12f/0x150
[   72.562710]  ? set_kthread_struct+0x50/0x50
[   72.563309]  ret_from_fork+0x22/0x30
[   72.563818]  </TASK>
[   72.564189] ---[ end trace 031117b1c72ec616 ]---
[   72.566019] list_add corruption. next->prev should be prev (ffff89ac4977e538), but was ffff89ac4763e018. (next=ffff89ac4763e018).
[   72.567647] ------------[ cut here ]------------

Fixes: a4abc6b12e ("nfsd: Fix svc_xprt refcnt leak when setup callback client failed")
Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Cc: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Dan Aloni <dan.aloni@vastdata.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-12 09:18:44 -05:00
Jeff Layton
ac3a2585f0 nfsd: rework refcounting in filecache
The filecache refcounting is a bit non-standard for something searchable
by RCU, in that we maintain a sentinel reference while it's hashed. This
in turn requires that we have to do things differently in the "put"
depending on whether its hashed, which we believe to have led to races.

There are other problems in here too. nfsd_file_close_inode_sync can end
up freeing an nfsd_file while there are still outstanding references to
it, and there are a number of subtle ToC/ToU races.

Rework the code so that the refcount is what drives the lifecycle. When
the refcount goes to zero, then unhash and rcu free the object. A task
searching for a nfsd_file is allowed to bump its refcount, but only if
it's not already 0. Ensure that we don't make any other changes to it
until a reference is held.

With this change, the LRU carries a reference. Take special care to deal
with it when removing an entry from the list, and ensure that we only
repurpose the nf_lru list_head when the refcount is 0 to ensure
exclusive access to it.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-11 11:03:09 -05:00
Kees Cook
e78e274eb2 NFSD: Avoid clashing function prototypes
When built with Control Flow Integrity, function prototypes between
caller and function declaration must match. These mismatches are visible
at compile time with the new -Wcast-function-type-strict in Clang[1].

There were 97 warnings produced by NFS. For example:

fs/nfsd/nfs4xdr.c:2228:17: warning: cast from '__be32 (*)(struct nfsd4_compoundargs *, struct nfsd4_access *)' (aka 'unsigned int (*)(struct nfsd4_compoundargs *, struct nfsd4_access *)') to 'nfsd4_dec' (aka 'unsigned int (*)(struct nfsd4_compoundargs *, void *)') converts to incompatible function type [-Wcast-function-type-strict]
        [OP_ACCESS]             = (nfsd4_dec)nfsd4_decode_access,
                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The enc/dec callbacks were defined as passing "void *" as the second
argument, but were being implicitly cast to a new type. Replace the
argument with union nfsd4_op_u, and perform explicit member selection
in the function body. There are no resulting binary differences.

Changes were made mechanically using the following Coccinelle script,
with minor by-hand fixes for members that didn't already match their
existing argument name:

@find@
identifier func;
type T, opsT;
identifier ops, N;
@@

 opsT ops[] = {
	[N] = (T) func,
 };

@already_void@
identifier find.func;
identifier name;
@@

 func(...,
-void
+union nfsd4_op_u
 *name)
 {
	...
 }

@proto depends on !already_void@
identifier find.func;
type T;
identifier name;
position p;
@@

 func@p(...,
 	T name
 ) {
	...
   }

@script:python get_member@
type_name << proto.T;
member;
@@

coccinelle.member = cocci.make_ident(type_name.split("_", 1)[1].split(' ',1)[0])

@convert@
identifier find.func;
type proto.T;
identifier proto.name;
position proto.p;
identifier get_member.member;
@@

 func@p(...,
-	T name
+	union nfsd4_op_u *u
 ) {
+	T name = &u->member;
	...
   }

@cast@
identifier find.func;
type T, opsT;
identifier ops, N;
@@

 opsT ops[] = {
	[N] =
-	(T)
	func,
 };

Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:13 -05:00
Chuck Lever
9315564747 NFSD: Use only RQ_DROPME to signal the need to drop a reply
Clean up: NFSv2 has the only two usages of rpc_drop_reply in the
NFSD code base. Since NFSv2 is going away at some point, replace
these in order to simplify the "drop this reply?" check in
nfsd_dispatch().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-12-10 11:01:13 -05:00
Dai Ngo
638593be55 NFSD: add CB_RECALL_ANY tracepoints
Add tracepoints to trace start and end of CB_RECALL_ANY operation.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
[ cel: added show_rca_mask() macro ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:12 -05:00
Dai Ngo
44df6f439a NFSD: add delegation reaper to react to low memory condition
The delegation reaper is called by nfsd memory shrinker's on
the 'count' callback. It scans the client list and sends the
courtesy CB_RECALL_ANY to the clients that hold delegations.

To avoid flooding the clients with CB_RECALL_ANY requests, the
delegation reaper sends only one CB_RECALL_ANY request to each
client per 5 seconds.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
[ cel: moved definition of RCA4_TYPE_MASK_RDATA_DLG ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:12 -05:00
Dai Ngo
3959066b69 NFSD: add support for sending CB_RECALL_ANY
Add XDR encode and decode function for CB_RECALL_ANY.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:12 -05:00
Dai Ngo
a1049eb47f NFSD: refactoring courtesy_client_reaper to a generic low memory shrinker
Refactoring courtesy_client_reaper to generic low memory
shrinker so it can be used for other purposes.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:12 -05:00
Brian Foster
79a1d88a36 NFSD: pass range end to vfs_fsync_range() instead of count
_nfsd_copy_file_range() calls vfs_fsync_range() with an offset and
count (bytes written), but the former wants the start and end bytes
of the range to sync. Fix it up.

Fixes: eac0b17a77 ("NFSD add vfs_fsync after async copy is done")
Signed-off-by: Brian Foster <bfoster@redhat.com>
Tested-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:12 -05:00
Xiu Jianfeng
85a0d0c9a5 NFSD: Use struct_size() helper in alloc_session()
Use struct_size() helper to simplify the code, no functional changes.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:11 -05:00
Jeff Layton
01d53a88c0 nfsd: return error if nfs4_setacl fails
With the addition of POSIX ACLs to struct nfsd_attrs, we no longer
return an error if setting the ACL fails. Ensure we return the na_aclerr
error on SETATTR if there is one.

Fixes: c0cbe70742 ("NFSD: add posix ACLs to struct nfsd_attrs")
Cc: Neil Brown <neilb@suse.de>
Reported-by: Yongcheng Yang <yoyang@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 11:01:11 -05:00
Chuck Lever
d7064eaf68 NFSD: Add an nfsd_file_fsync tracepoint
Add a tracepoint to capture the number of filecache-triggered fsync
calls and which files needed it. Also, record when an fsync triggers
a write verifier reset.

Examples:

<...>-97    [007]   262.505611: nfsd_file_free:       inode=0xffff888171e08140 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d2400
<...>-97    [007]   262.505612: nfsd_file_fsync:      inode=0xffff888171e08140 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d2400 ret=0
<...>-97    [007]   262.505623: nfsd_file_free:       inode=0xffff888171e08dc0 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d1e00
<...>-97    [007]   262.505624: nfsd_file_fsync:      inode=0xffff888171e08dc0 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d1e00 ret=0

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-12-10 11:00:04 -05:00
Jeff Layton
22ae4c114f nfsd: fix up the filecache laundrette scheduling
We don't really care whether there are hashed entries when it comes to
scheduling the laundrette. They might all be non-gc entries, after all.
We only want to schedule it if there are entries on the LRU.

Switch to using list_lru_count, and move the check into
nfsd_file_gc_worker. The other callsite in nfsd_file_put doesn't need to
count entries, since it only schedules the laundrette after adding an
entry to the LRU.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10 10:59:20 -05:00
Jeff Layton
8214118589 nfsd: reorganize filecache.c
In a coming patch, we're going to rework how the filecache refcounting
works. Move some code around in the function to reduce the churn in the
later patches, and rename some of the functions with (hopefully) clearer
names: nfsd_file_flush becomes nfsd_file_fsync, and
nfsd_file_unhash_and_dispose is renamed to nfsd_file_unhash_and_queue.

Also, the nfsd_file_put_final tracepoint is renamed to nfsd_file_free,
to better match the name of the function from which it's called.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28 12:54:48 -05:00
Jeff Layton
1f696e230e nfsd: remove the pages_flushed statistic from filecache
We're counting mapping->nrpages, but not all of those are necessarily
dirty. We don't really have a simple way to count just the dirty pages,
so just remove this stat since it's not accurate.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28 12:54:47 -05:00
Chuck Lever
3f054211b2 NFSD: Fix licensing header in filecache.c
Add a missing SPDX header.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28 12:54:47 -05:00
Chuck Lever
d47b295e8d NFSD: Use rhashtable for managing nfs4_file objects
fh_match() is costly, especially when filehandles are large (as is
the case for NFSv4). It needs to be used sparingly when searching
data structures. Unfortunately, with common workloads, I see
multiple thousands of objects stored in file_hashtbl[], which has
just 256 buckets, making its bucket hash chains quite lengthy.

Walking long hash chains with the state_lock held blocks other
activity that needs that lock. Sizable hash chains are a common
occurrance once the server has handed out some delegations, for
example -- IIUC, each delegated file is held open on the server by
an nfs4_file object.

To help mitigate the cost of searching with fh_match(), replace the
nfs4_file hash table with an rhashtable, which can dynamically
resize its bucket array to minimize hash chain length.

The result of this modification is an improvement in the latency of
NFSv4 operations, and the reduction of nfsd CPU utilization due to
eliminating the cost of multiple calls to fh_match() and reducing
the CPU cache misses incurred while walking long hash chains in the
nfs4_file hash table.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28 12:54:47 -05:00
Chuck Lever
1542474800 NFSD: Refactor find_file()
find_file() is now the only caller of find_file_locked(), so just
fold these two together.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28 12:54:47 -05:00
Chuck Lever
9270fc514b NFSD: Clean up find_or_add_file()
Remove the call to find_file_locked() in insert_nfs4_file(). Tracing
shows that over 99% of these calls return NULL. Thus it is not worth
the expense of the extra bucket list traversal. insert_file() already
deals correctly with the case where the item is already in the hash
bucket.

Since nfsd4_file_hash_insert() is now just a wrapper around
insert_file(), move the meat of insert_file() into
nfsd4_file_hash_insert() and get rid of it.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
2022-11-28 12:54:47 -05:00
Chuck Lever
3341678f2f NFSD: Add a nfsd4_file_hash_remove() helper
Refactor to relocate hash deletion operation to a helper function
that is close to most other nfs4_file data structure operations.

The "noinline" annotation will become useful in a moment when the
hlist_del_rcu() is replaced with a more complex rhash remove
operation. It also guarantees that hash remove operations can be
traced with "-p function -l remove_nfs4_file_locked".

This also simplifies the organization of forward declarations: the
to-be-added rhashtable and its param structure will be defined
/after/ put_nfs4_file().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28 12:54:47 -05:00
Chuck Lever
81a21fa3e7 NFSD: Clean up nfsd4_init_file()
Name this function more consistently. I'm going to use nfsd4_file_
and nfsd4_file_hash_ for these helpers.

Change the @fh parameter to be const pointer for better type safety.

Finally, move the hash insertion operation to the caller. This is
typical for most other "init_object" type helpers, and it is where
most of the other nfs4_file hash table operations are located.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28 12:54:46 -05:00
Chuck Lever
3fe828cadd NFSD: Update file_hashtbl() helpers
Enable callers to use const pointers for type safety.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28 12:54:46 -05:00
Chuck Lever
b48f8056c0 NFSD: Use const pointers as parameters to fh_ helpers
Enable callers to use const pointers where they are able to.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
2022-11-28 12:54:46 -05:00
Chuck Lever
a1c74569bb NFSD: Trace delegation revocations
Delegation revocation is an exceptional event that is not otherwise
visible externally (eg, no network traffic is emitted). Generate a
trace record when it occurs so that revocation can be observed or
other activity can be triggered. Example:

nfsd-1104  [005]  1912.002544: nfsd_stid_revoke:        client 633c9343:4e82788d stateid 00000003:00000001 ref=2 type=DELEG

Trace infrastructure is provided for subsequent additional tracing
related to nfs4_stid activity.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28 12:54:46 -05:00
Chuck Lever
20eee313ff NFSD: Trace stateids returned via DELEGRETURN
Handing out a delegation stateid is recorded with the
nfsd_deleg_read tracepoint, but there isn't a matching tracepoint
for recording when the stateid is returned.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28 12:54:46 -05:00
Chuck Lever
eeff73f7c1 NFSD: Clean up nfs4_preprocess_stateid_op() call sites
Remove the lame-duck dprintk()s around nfs4_preprocess_stateid_op()
call sites.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
2022-11-28 12:54:46 -05:00
Chuck Lever
b3276c1f5b NFSD: Flesh out a documenting comment for filecache.c
Record what we've learned recently about the NFSD filecache in a
documenting comment so our future selves don't forget what all this
is for.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28 12:54:45 -05:00
Chuck Lever
4d1ea84557 NFSD: Add an NFSD_FILE_GC flag to enable nfsd_file garbage collection
NFSv4 operations manage the lifetime of nfsd_file items they use by
means of NFSv4 OPEN and CLOSE. Hence there's no need for them to be
garbage collected.

Introduce a mechanism to enable garbage collection for nfsd_file
items used only by NFSv2/3 callers.

Note that the change in nfsd_file_put() ensures that both CLOSE and
DELEGRETURN will actually close out and free an nfsd_file on last
reference of a non-garbage-collected file.

Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=394
Suggested-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28 12:54:45 -05:00
Chuck Lever
dcf3f80965 NFSD: Revert "NFSD: NFSv4 CLOSE should release an nfsd_file immediately"
This reverts commit 5e138c4a75.

That commit attempted to make files available to other users as soon
as all NFSv4 clients were done with them, rather than waiting until
the filecache LRU had garbage collected them.

It gets the reference counting wrong, for one thing.

But it also misses that DELEGRETURN should release a file in the
same fashion. In fact, any nfsd_file_put() on an file held open
by an NFSv4 client needs potentially to release the file
immediately...

Clear the way for implementing that idea.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
2022-11-28 12:54:45 -05:00
Chuck Lever
c252849082 NFSD: Pass the target nfsd_file to nfsd_commit()
In a moment I'm going to introduce separate nfsd_file types, one of
which is garbage-collected; the other, not. The garbage-collected
variety is to be used by NFSv2 and v3, and the non-garbage-collected
variety is to be used by NFSv4.

nfsd_commit() is invoked by both NFSv3 and NFSv4 consumers. We want
nfsd_commit() to find and use the correct variety of cached
nfsd_file object for the NFS version that is in use.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
2022-11-28 12:54:45 -05:00
Jeff Layton
e0aa651068 nfsd: don't call nfsd_file_put from client states seqfile display
We had a report of this:

    BUG: sleeping function called from invalid context at fs/nfsd/filecache.c:440

...with a stack trace showing nfsd_file_put being called from
nfs4_show_open. This code has always tried to call fput while holding a
spinlock, but we recently changed this to use the filecache, and that
started triggering the might_sleep() in nfsd_file_put.

states_start takes and holds the cl_lock while iterating over the
client's states, and we can't sleep with that held.

Have the various nfs4_show_* functions instead hold the fi_lock instead
of taking a nfsd_file reference.

Fixes: 78599c42ae ("nfsd4: add file to display list of client's opens")
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2138357
Reported-by: Zhi Li <yieli@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28 12:54:45 -05:00
Jeff Layton
2f3a4b2ac2 nfsd: allow disabling NFSv2 at compile time
rpc.nfsd stopped supporting NFSv2 a year ago. Take the next logical
step toward deprecating it and allow NFSv2 support to be compiled out.

Add a new CONFIG_NFSD_V2 option that can be turned off and rework the
CONFIG_NFSD_V?_ACL option dependencies. Add a description that
discourages enabling it.

Also, change the description of CONFIG_NFSD to state that the always-on
version is now 3 instead of 2.

Finally, add an #ifdef around "case 2:" in __write_versions. When NFSv2
is disabled at compile time, this should make the kernel ignore attempts
to disable it at runtime, but still error out when trying to enable it.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28 12:54:45 -05:00
Jeff Layton
cb12fae1c3 nfsd: move nfserrno() to vfs.c
nfserrno() is common to all nfs versions, but nfsproc.c is specifically
for NFSv2. Move it to vfs.c, and the prototype to vfs.h.

While we're in here, remove the #ifdef EDQUOT check in this function.
It's apparently a holdover from the initial merge of the nfsd code in
1997. No other place in the kernel checks that that symbol is defined
before using it, so I think we can dispense with it here.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28 12:54:44 -05:00
Jeff Layton
8e823bafff nfsd: ignore requests to disable unsupported versions
The kernel currently errors out if you attempt to enable or disable a
version that it doesn't recognize. Change it to ignore attempts to
disable an unrecognized version. If we don't support it, then there is
no harm in doing so.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28 12:54:44 -05:00
Chuck Lever
841fd0a3cb NFSD: Finish converting the NFSv3 GETACL result encoder
For some reason, the NFSv2 GETACL result encoder was fully converted
to use the new nfs_stream_encode_acl(), but the NFSv3 equivalent was
not similarly converted.

Fixes: 20798dfe24 ("NFSD: Update the NFSv3 GETACL result encoder to use struct xdr_stream")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28 12:54:44 -05:00
Chuck Lever
ea5021e911 NFSD: Finish converting the NFSv2 GETACL result encoder
The xdr_stream conversion inadvertently left some code that set the
page_len of the send buffer. The XDR stream encoders should handle
this automatically now.

This oversight adds garbage past the end of the Reply message.
Clients typically ignore the garbage, but NFSD does not need to send
it, as it leaks stale memory contents onto the wire.

Fixes: f8cba47344 ("NFSD: Update the NFSv2 GETACL result encoder to use struct xdr_stream")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28 12:54:44 -05:00
Colin Ian King
69eed23baf NFSD: Remove redundant assignment to variable host_err
Variable host_err is assigned a value that is never read, it is being
re-assigned a value in every different execution path in the following
switch statement. The assignment is redundant and can be removed.

Cleans up clang-scan warning:
warning: Value stored to 'host_err' is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28 12:54:44 -05:00
Anna Schumaker
eeadcb7579 NFSD: Simplify READ_PLUS
Chuck had suggested reverting READ_PLUS so it returns a single DATA
segment covering the requested read range. This prepares the server for
a future "sparse read" function so support can easily be added without
needing to rip out the old READ_PLUS code at the same time.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28 12:54:43 -05:00
Linus Torvalds
cf562a45a0 Amir's copy_file_range() fix
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCY4OtEwAKCRBZ7Krx/gZQ
 66LvAP9tMMKsXoZY5dNjkAeQo/I5PHx81iLYu5GyigqTsf0g8gD+MeM2qxQE9QTt
 6gngWpnNif7Pe5Jj5yuwl4IGbjDG9AQ=
 =Tx7P
 -----END PGP SIGNATURE-----

Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs fix from Al Viro:
 "Amir's copy_file_range() fix"

* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: fix copy_file_range() averts filesystem freeze protection
2022-11-27 12:40:06 -08:00
Linus Torvalds
e5f3ec38c8 Fixes:
- Fix rare data corruption on READ operations
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEKLLlsBKG3yQ88j7+M2qzM29mf5cFAmOCPhcACgkQM2qzM29m
 f5ewTRAAuAjJvtnsRxZBILs76U3KpAnn3ghtYKtzCmanq1UEJAlTz5vLLCqJRTXw
 OajN4f/T/kD3bY5XxYcsbSMhVJhgd7JMx/DyPjp3rY+nS1cS/CB+TxN3VqhOZJDl
 MfEJTN0MxWrq0pXKYxuPECmwk/C7jAU4vjWU+sDWhu4Anig564fdPxGGWw9vRfh5
 YP8U8cuM5LIFCM2ZSjPsqWEXgd7pbYpYdOx6JPA74ftia8RBU1YVbIqZ6uFXiTnV
 tpKAuQYem2ixV6UfsrVbeHDfsSkQcX2iaTGlcLB5y12nprV0wTOQM6lONTD878vh
 37oc8zG9cdpWfcRzkyB8a58jHfSk74pMkV300C38CeV1KtajFVoRkoTvLYJdxbf8
 WPcRcbsXbotb4+A1D2H6QvPKUbrlK+HIHe8POU67tKq5BI8xRw+ojTsJ2ANYr9Jt
 OviLUraUnKFvCK2LN03+Op4l+UBTIdOGzGMqveILfxPD6zlTYJbQQ64Nih4JLfJG
 uDN2892H4He3he5oD9Dzoh2xSWfLV5PJEAaN9wW7pyv8D5HfYBXWPan6JeaMHnfW
 +NcoFQ3cSewyMZ1Rw0aCsKfXRGwikJrbAsrlvNe+uFRD6ueeWULp5fnTlOn+0tW1
 tp+EzLOMoNkL9NW/rLeCIPN1MNXzgabgd4Diq8U3iTDRxf0FahU=
 =zxjk
 -----END PGP SIGNATURE-----

Merge tag 'nfsd-6.1-6' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fix from Chuck Lever:

 - Fix rare data corruption on READ operations

* tag 'nfsd-6.1-6' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  NFSD: Fix reads with a non-zero offset that don't end on a page boundary
2022-11-26 12:25:49 -08:00
Amir Goldstein
10bc8e4af6 vfs: fix copy_file_range() averts filesystem freeze protection
Commit 868f9f2f8e ("vfs: fix copy_file_range() regression in cross-fs
copies") removed fallback to generic_copy_file_range() for cross-fs
cases inside vfs_copy_file_range().

To preserve behavior of nfsd and ksmbd server-side-copy, the fallback to
generic_copy_file_range() was added in nfsd and ksmbd code, but that
call is missing sb_start_write(), fsnotify hooks and more.

Ideally, nfsd and ksmbd would pass a flag to vfs_copy_file_range() that
will take care of the fallback, but that code would be subtle and we got
vfs_copy_file_range() logic wrong too many times already.

Instead, add a flag to explicitly request vfs_copy_file_range() to
perform only generic_copy_file_range() and let nfsd and ksmbd use this
flag only in the fallback path.

This choise keeps the logic changes to minimum in the non-nfsd/ksmbd code
paths to reduce the risk of further regressions.

Fixes: 868f9f2f8e ("vfs: fix copy_file_range() regression in cross-fs copies")
Tested-by: Namjae Jeon <linkinjeon@kernel.org>
Tested-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-11-25 00:52:28 -05:00
Chuck Lever
ac8db824ea NFSD: Fix reads with a non-zero offset that don't end on a page boundary
This was found when virtual machines with nfs-mounted qcow2 disks
failed to boot properly.

Reported-by: Anders Blomdell <anders.blomdell@control.lth.se>
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2142132
Fixes: bfbfb6182a ("nfsd_splice_actor(): handle compound pages")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-23 14:32:35 -05:00