The filecache lru is walked in 2 circumstances for 2 different reasons.
1/ When called from the shrinker we want to discard the first few
entries on the list, ignoring any with NFSD_FILE_REFERENCED set
because they should really be at the end of the LRU as they have been
referenced recently. So those ones are ROTATED.
2/ When called from the nfsd_file_gc() timer function we want to discard
anything that hasn't been used since before the previous call, and
mark everything else as unused at this point in time.
Using the same flag for both of these can result in some unexpected
outcomes. If the shrinker callback clears NFSD_FILE_REFERENCED then
nfsd_file_gc() will think the file hasn't been used in a while, while
really it has.
I think it is easier to reason about the behaviour if we instead have
two flags.
NFSD_FILE_REFERENCED means "this should be at the end of the LRU, please
put it there when convenient"
NFSD_FILE_RECENT means "this has been used recently - since the last
run of nfsd_file_gc()
When either caller finds an NFSD_FILE_REFERENCED entry, that entry
should be moved to the end of the LRU and the flag cleared. This can
safely happen at any time. The actual order on the lru might not be
strictly least-recently-used, but that is normal for linux lrus.
The shrinker callback can ignore the "recent" flag. If it ends up
freeing something that is "recent" that simply means that memory
pressure is sufficient to limit the acceptable cache age to less than
the nfsd_file_gc frequency.
The gc callback should primarily focus on NFSD_FILE_RECENT. It should
free everything that doesn't have this flag set, and should clear the
flag on everything else. When it clears the flag it is convenient to
clear the "REFERENCED" flag and move to the end of the LRU too.
With this, calls from the shrinker do not prematurely age files. It
will focus only on freeing those that are least recently used.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
list_lru_walk() is only useful when the aim is to remove all elements
from the list_lru. It will repeatedly visit rotated elements of the
first per-node sublist before proceeding to subsequent sublists.
This patch changes nfsd_file_gc() to use list_lru_walk_node() and
list_lru_count_node() on each NUMA node.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_file_close_inode_sync() contains an exact copy of
nfsd_file_dispose_list().
This patch removes that copy and calls nfsd_file_dispose_list()
instead.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Dave opines:
IMO, there is no need to do this unnecessary work on every object
that is added to the LRU. Changing the gc worker to always run
every 2s and check if it has work to do like so:
static void
nfsd_file_gc_worker(struct work_struct *work)
{
- nfsd_file_gc();
- if (list_lru_count(&nfsd_file_lru))
- nfsd_file_schedule_laundrette();
+ if (list_lru_count(&nfsd_file_lru))
+ nfsd_file_gc();
+ nfsd_file_schedule_laundrette();
}
means that nfsd_file_gc() will be run the same way and have the same
behaviour as the current code. When the system it idle, it does a
list_lru_count() check every 2 seconds and goes back to sleep.
That's going to be pretty much unnoticable on most machines that run
NFS servers.
Suggested-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The race that this code tries to protect against is not interesting.
The code is problematic as we access the "nf" after we have given our
reference to the lru system. While that takes 2+ seconds to free
things, it is still poor form.
The only interesting race I can find would be with
nfsd_file_close_inode_sync();
This is the only place that really doesn't want the file to stay on the
LRU when unhashed (which is the direct consequence of the race).
However for the race to happen, some other thread must own a reference
to a file and be putting it while nfsd_file_close_inode_sync() is trying
to close all files for an inode. If this is possible, that other thread
could simply call nfsd_file_put() a little bit later and the result
would be the same: not all files are closed when
nfsd_file_close_inode_sync() completes.
If this was really a problem, we would need to wait in close_inode_sync
for the other references to be dropped. We probably don't want to do
that.
So it is best to simply remove this code.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
fs/nfsd/nfs4callback.c implements a callback client. Thus its XDR
decoders are decoding replies, not calls.
NFS4ERR_BAD_XDR is an on-the-wire status code that reports that the
client sent a corrupted RPC /call/. It's not used as the internal
error code when a /reply/ can't be decoded, since that kind of
failure is never reported to the sender of that RPC message.
Instead, a reply decoder should return -EIO, as the reply decoders
in the NFS client do.
Fixes: 6487a13b5c ("NFSD: add support for CB_GETATTR callback")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
On a SEQ_MISORDERED error, the current code will reattempt the call, but
set the slot sequence ID to 1. I can find no mention of this remedy in
the spec, and it seems potentially dangerous. It's possible that the
last call was sent with seqid 1, and doing this will cause a
retransmission of the reply.
Drop this special handling, and always treat SEQ_MISORDERED like
BADSLOT. Retry the call, but leak the slot so that it is no longer used.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently it just restarts the call, without getting a new slot.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
ESERVERFAULT means that the server sent a successful and legitimate
reply, but the session info didn't match what was expected. Don't
increment the seq_nr in that case.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd4_cb_sequence_done() currently checks RPC_SIGNALLED() when
processing the compound and releasing the slot. If RPC_SIGNALLED()
returns true, then that means that the client is going to be torn down.
Don't check RPC_SIGNALLED() after processing a successful reply. Check
it only before restarting the rpc_task. If it returns true, then requeue
the callback instead of restarting the task.
Also, handle rpc_restart_call() and rpc_restart_call_prepare() failures
correctly, by requeueing the callback.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If the callback is going to be requeued to the workqueue, then release
the slot. The callback client and session could change and the slot may
no longer be valid after that point.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
It's a bit strange to call nfsd4_cb_sequence_done() on a callback with no
CB_SEQUENCE. Lift the handling of restarting a call into a new helper,
and move the handling of NFSv4.0 into nfsd4_cb_done().
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
There is only one case where we want to proceed with processing the rest
of the CB_COMPOUND, and that's when the cb_seq_status is 0. Make the
default return value be false, and only set it to true in that case.
Rename the "need_restart" label to "requeue", to better indicate that
it's being requeued to the workqueue.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Before calling nfsd4_run_cb to queue dl_recall to the callback_wq, we
increment the reference count of dl_stid.
We expect that after the corresponding work_struct is processed, the
reference count of dl_stid will be decremented through the callback
function nfsd4_cb_recall_release.
However, if the call to nfsd4_run_cb fails, the incremented reference
count of dl_stid will not be decremented correspondingly, leading to the
following nfs4_stid leak:
unreferenced object 0xffff88812067b578 (size 344):
comm "nfsd", pid 2761, jiffies 4295044002 (age 5541.241s)
hex dump (first 32 bytes):
01 00 00 00 6b 6b 6b 6b b8 02 c0 e2 81 88 ff ff ....kkkk........
00 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 ad 4e ad de .kkkkkkk.....N..
backtrace:
kmem_cache_alloc+0x4b9/0x700
nfsd4_process_open1+0x34/0x300
nfsd4_open+0x2d1/0x9d0
nfsd4_proc_compound+0x7a2/0xe30
nfsd_dispatch+0x241/0x3e0
svc_process_common+0x5d3/0xcc0
svc_process+0x2a3/0x320
nfsd+0x180/0x2e0
kthread+0x199/0x1d0
ret_from_fork+0x30/0x50
ret_from_fork_asm+0x1b/0x30
unreferenced object 0xffff8881499f4d28 (size 368):
comm "nfsd", pid 2761, jiffies 4295044005 (age 5541.239s)
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 30 4d 9f 49 81 88 ff ff ........0M.I....
30 4d 9f 49 81 88 ff ff 20 00 00 00 01 00 00 00 0M.I.... .......
backtrace:
kmem_cache_alloc+0x4b9/0x700
nfs4_alloc_stid+0x29/0x210
alloc_init_deleg+0x92/0x2e0
nfs4_set_delegation+0x284/0xc00
nfs4_open_delegation+0x216/0x3f0
nfsd4_process_open2+0x2b3/0xee0
nfsd4_open+0x770/0x9d0
nfsd4_proc_compound+0x7a2/0xe30
nfsd_dispatch+0x241/0x3e0
svc_process_common+0x5d3/0xcc0
svc_process+0x2a3/0x320
nfsd+0x180/0x2e0
kthread+0x199/0x1d0
ret_from_fork+0x30/0x50
ret_from_fork_asm+0x1b/0x30
Fix it by checking the result of nfsd4_run_cb and call nfs4_put_stid if
fail to queue dl_recall.
Cc: stable@vger.kernel.org
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The pynfs DELEG8 test fails when run against nfsd. It acquires a
delegation and then lets the lease time out. It then tries to use the
deleg stateid and expects to see NFS4ERR_DELEG_REVOKED, but it gets
bad NFS4ERR_BAD_STATEID instead.
When a delegation is revoked, it's initially marked with
SC_STATUS_REVOKED, or SC_STATUS_ADMIN_REVOKED and later, it's marked
with the SC_STATUS_FREEABLE flag, which denotes that it is waiting for
s FREE_STATEID call.
nfs4_lookup_stateid() accepts a statusmask that includes the status
flags that a found stateid is allowed to have. Currently, that mask
never includes SC_STATUS_FREEABLE, which means that revoked delegations
are (almost) never found.
Add SC_STATUS_FREEABLE to the always-allowed status flags, and remove it
from nfsd4_delegreturn() since it's now always implied.
Fixes: 8dd91e8d31 ("nfsd: fix race between laundromat and free_stateid")
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently, nfsd_proc_stat_init() ignores the return value of
svc_proc_register(). If the procfile creation fails, then the kernel
will WARN when it tries to remove the entry later.
Fix nfsd_proc_stat_init() to return the same type of pointer as
svc_proc_register(), and fix up nfsd_net_init() to check that and fail
the nfsd_net construction if it occurs.
svc_proc_register() can fail if the dentry can't be allocated, or if an
identical dentry already exists. The second case is pretty unlikely in
the nfsd_net construction codepath, so if this happens, return -ENOMEM.
Reported-by: syzbot+e34ad04f27991521104c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-nfs/67a47501.050a0220.19061f.05f9.GAE@google.com/
Cc: stable@vger.kernel.org # v6.9
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
While running down the problem triggered by disconnect injection,
I noticed the "in use" string was actually never hooked up in this
trace point, so it always showed the traced slot as not in use. But
what might be more useful is showing all the slot status flags.
Also, this trace point can record and report the slot's index
number, which among other things is useful for troubleshooting slot
table expansion and contraction.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
RFC 8881 Section 18.9.4 paragraphs 1 - 2 tell us that RENAME should
return NFS4ERR_FILE_OPEN only when the target object is a file that
is currently open. If the target is a directory, some other status
must be returned.
The VFS is unlikely to return -EBUSY, but NFSD has to ensure that
errno does not leak to clients as a status code that is not
permitted by spec.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
RFC 8881 Section 18.26.4 paragraphs 1 - 3 tell us that RENAME should
return NFS4ERR_FILE_OPEN only when the target object is a file that
is currently open. If the target is a directory, some other status
must be returned.
Generally I expect that a delegation recall will be triggered in
some of these circumstances. In other cases, the VFS might return
-EBUSY for other reasons, and NFSD has to ensure that errno does
not leak to clients as a status code that is not permitted by spec.
There are some error flows where the target dentry hasn't been
found yet. The default value for @type therefore is S_IFDIR to return
an alternate status code in those cases.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
RFC 8881 Section 18.25.4 paragraph 5 tells us that the server
should return NFS4ERR_FILE_OPEN only if the target object is an
opened file. This suggests that returning this status when removing
a directory will confuse NFS clients.
This is a version-specific issue; nfsd_proc_remove/rmdir() and
nfsd3_proc_remove/rmdir() already return nfserr_access as
appropriate.
Unfortunately there is no quick way for nfsd4_remove() to determine
whether the target object is a file or not, so the check is done in
in nfsd_unlink() for now.
Reported-by: Trond Myklebust <trondmy@hammerspace.com>
Fixes: 466e16f092 ("nfsd: check for EBUSY from vfs_rmdir/vfs_unink.")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If fh_fill_pre_attrs() returns a non-zero status, the error flow
takes it through out_unlock, which then overwrites the returned
status code with
err = nfserrno(host_err);
Fixes: a332018a91 ("nfsd: handle failure to collect pre/post-op attrs more sanely")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
There two mappings of nfserr_mlink in nfs_errtbl.
Remove one of them.
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
NFSD sends CB_RECALL_ANY to clients when the server is low on
memory or that client has a large number of delegations outstanding.
We've seen cases where NFSD attempts to send CB_RECALL_ANY requests
to disconnected clients, and gets confused. These calls never go
anywhere if a backchannel transport to the target client isn't
available. Before the server can send any backchannel operation, the
client has to connect first and then do a BIND_CONN_TO_SESSION.
This patch doesn't address the root cause of the confusion, but
there's no need to queue up these optional operations if they can't
go anywhere.
Fixes: 44df6f439a ("NFSD: add delegation reaper to react to low memory condition")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
A WARN_ON_ONCE() is added to revoke delegations to make sure that the
state has been marked for revocation. However, that's only true for 4.1+
stateids. For 4.0 stateids, in unhash_delegation_locked() the sc_status
is set to SC_STATUS_CLOSED. Modify the check to reflect it, otherwise
a WARN_ON_ONCE is erronously triggered.
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
vfs_mkdir() does not guarantee to leave the child dentry hashed or make
it positive on success, and in many such cases the filesystem had to use
a different dentry which it can now return.
This patch changes vfs_mkdir() to return the dentry provided by the
filesystems which is hashed and positive when provided. This reduces
the number of cases where the resulting dentry is not positive to a
handful which don't deserve extra efforts.
The only callers of vfs_mkdir() which are interested in the resulting
inode are in-kernel filesystem clients: cachefiles, nfsd, smb/server.
The only filesystems that don't reliably provide the inode are:
- kernfs, tracefs which these clients are unlikely to be interested in
- cifs in some configurations would need to do a lookup to find the
created inode, but doesn't. cifs cannot be exported via NFS, is
unlikely to be used by cachefiles, and smb/server only has a soft
requirement for the inode, so this is unlikely to be a problem in
practice.
- hostfs, nfs, cifs may need to do a lookup (rarely for NFS) and it is
possible for a race to make that lookup fail. Actual failure
is unlikely and providing callers handle negative dentries graceful
they will fail-safe.
So this patch removes the lookup code in nfsd and smb/server and adjusts
them to fail safe if a negative dentry is provided:
- cache-files already fails safe by restarting the task from the
top - it still does with this change, though it no longer calls
cachefiles_put_directory() as that will crash if the dentry is
negative.
- nfsd reports "Server-fault" which it what it used to do if the lookup
failed. This will never happen on any file-systems that it can actually
export, so this is of no consequence. I removed the fh_update()
call as that is not needed and out-of-place. A subsequent
nfsd_create_setattr() call will call fh_update() when needed.
- smb/server only wants the inode to call ksmbd_smb_inherit_owner()
which updates ->i_uid (without calling notify_change() or similar)
which can be safely skipping on cifs (I hope).
If a different dentry is returned, the first one is put. If necessary
the fact that it is new can be determined by comparing pointers. A new
dentry will certainly have a new pointer (as the old is put after the
new is obtained).
Similarly if an error is returned (via ERR_PTR()) the original dentry is
put.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250227013949.536172-7-neilb@suse.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
nfsd_create_locked() doesn't need to explicitly call fh_update().
On success (which is the only time that fh_update() matters at all),
nfsd_create_setattr() will be called and it will call fh_update().
This extra call is not harmful, but is not necessary.
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250226062135.2043651-3-neilb@suse.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
- Introduced during the v6.14 merge window:
- A fix for CB_GETATTR reply decoding was not quite correct
- Fix the NFSD connection limiting logic
- Fix a bug in the new session table resizing logic
- Bugs that pre-date v6.14
- Support for courteous clients (5.19) introduced a shutdown hang
- Fix a crash in the filecache laundrette (6.9)
- Fix a zero-day crash in NFSD's NFSv3 ACL implementation
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Merge tag 'nfsd-6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd fixes from Chuck Lever:
"Fixes for new bugs:
- A fix for CB_GETATTR reply decoding was not quite correct
- Fix the NFSD connection limiting logic
- Fix a bug in the new session table resizing logic
Bugs that pre-date v6.14:
- Support for courteous clients (5.19) introduced a shutdown hang
- Fix a crash in the filecache laundrette (6.9)
- Fix a zero-day crash in NFSD's NFSv3 ACL implementation"
* tag 'nfsd-6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
NFSD: Fix CB_GETATTR status fix
NFSD: fix hang in nfsd4_shutdown_callback
nfsd: fix __fh_verify for localio
nfsd: fix uninitialised slot info when a request is retried
nfsd: validate the nfsd_serv pointer before calling svc_wake_up
nfsd: clear acl_access/acl_default after releasing them
Jeff says:
Now that I look, 1b3e26a5cc is wrong. The patch on the ml was correct, but
the one that got committed is different. It should be:
status = decode_cb_op_status(xdr, OP_CB_GETATTR, &cb->cb_status);
if (unlikely(status || cb->cb_status))
If "status" is non-zero, decoding failed (usu. BADXDR), but we also want to
bail out and not decode the rest of the call if the decoded cb_status is
non-zero. That's not happening here, cb_seq_status has already been checked and
is non-zero, so this ends up trying to decode the rest of the CB_GETATTR reply
when it doesn't exist.
Reported-by: Jeff Layton <jlayton@kernel.org>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219737
Fixes: 1b3e26a5cc ("NFSD: fix decoding in nfs4_xdr_dec_cb_getattr")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If nfs4_client is in courtesy state then there is no point to send
the callback. This causes nfsd4_shutdown_callback to hang since
cl_cb_inflight is not 0. This hang lasts about 15 minutes until TCP
notifies NFSD that the connection was dropped.
This patch modifies nfsd4_run_cb_work to skip the RPC call if
nfs4_client is in courtesy state.
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Fixes: 66af257999 ("NFSD: add courteous server support for thread with only delegation")
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
__fh_verify() added a call to svc_xprt_set_valid() to help do connection
management but during LOCALIO path rqstp argument is NULL, leading to
NULL pointer dereferencing and a crash.
Fixes: eccbbc7c00 ("nfsd: don't use sv_nrthreads in connection limiting calculations.")
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
A recent patch moved the assignment of seq->maxslots from before the
test for a resent request (which ends with a goto) to after, resulting
in it not being run in that case. This results in the server returning
bogus "high slot id" and "target high slot id" values.
The assignments to ->maxslots and ->target_maxslots need to be *after*
the out: label so that the correct values are returned in replies to
requests that are served from cache.
Fixes: 60aa656431 ("nfsd: allocate new session-based DRC slots on demand.")
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_file_dispose_list_delayed can be called from the filecache
laundrette, which is shut down after the nfsd threads are shut down and
the nfsd_serv pointer is cleared. If nn->nfsd_serv is NULL then there
are no threads to wake.
Ensure that the nn->nfsd_serv pointer is non-NULL before calling
svc_wake_up in nfsd_file_dispose_list_delayed. This is safe since the
svc_serv is not freed until after the filecache laundrette is cancelled.
Reported-by: Salvatore Bonaccorso <carnil@debian.org>
Closes: https://bugs.debian.org/1093734
Fixes: ffb4025961 ("nfsd: Don't leave work of closing files to a work queue")
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
New Features:
* Enable using direct IO with localio
* Added localio related tracepoints
Bugfixes:
* Sunrpc fixes for working with a very large cl_tasks list
* Fix a possible buffer overflow in nfs_sysfs_link_rpc_client()
* Fixes for handling reconnections with localio
* Fix how the NFS_FSCACHE kconfig option interacts with NETFS_SUPPORT
* Fix COPY_NOTIFY xdr_buf size calculations
* pNFS/Flexfiles fix for retrying requesting a layout segment for reads
* Sunrpc fix for retrying on EKEYEXPIRED error when the TGT is expired
Cleanups:
* Various other nfs & nfsd localio cleanups
* Prepratory patches for async copy improvements that are under development
* Make OFFLOAD_CANCEL, LAYOUTSTATS, and LAYOUTERR moveable to other xprts
* Add netns inum and srcaddr to debugfs rpc_xprt info
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Merge tag 'nfs-for-6.14-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
Pull NFS client updates from Anna Schumaker:
"New Features:
- Enable using direct IO with localio
- Added localio related tracepoints
Bugfixes:
- Sunrpc fixes for working with a very large cl_tasks list
- Fix a possible buffer overflow in nfs_sysfs_link_rpc_client()
- Fixes for handling reconnections with localio
- Fix how the NFS_FSCACHE kconfig option interacts with NETFS_SUPPORT
- Fix COPY_NOTIFY xdr_buf size calculations
- pNFS/Flexfiles fix for retrying requesting a layout segment for
reads
- Sunrpc fix for retrying on EKEYEXPIRED error when the TGT is
expired
Cleanups:
- Various other nfs & nfsd localio cleanups
- Prepratory patches for async copy improvements that are under
development
- Make OFFLOAD_CANCEL, LAYOUTSTATS, and LAYOUTERR moveable to other
xprts
- Add netns inum and srcaddr to debugfs rpc_xprt info"
* tag 'nfs-for-6.14-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (28 commits)
SUNRPC: do not retry on EKEYEXPIRED when user TGT ticket expired
sunrpc: add netns inum and srcaddr to debugfs rpc_xprt info
pnfs/flexfiles: retry getting layout segment for reads
NFSv4.2: make LAYOUTSTATS and LAYOUTERROR MOVEABLE
NFSv4.2: mark OFFLOAD_CANCEL MOVEABLE
NFSv4.2: fix COPY_NOTIFY xdr buf size calculation
NFS: Rename struct nfs4_offloadcancel_data
NFS: Fix typo in OFFLOAD_CANCEL comment
NFS: CB_OFFLOAD can return NFS4ERR_DELAY
nfs: Make NFS_FSCACHE select NETFS_SUPPORT instead of depending on it
nfs: fix incorrect error handling in LOCALIO
nfs: probe for LOCALIO when v3 client reconnects to server
nfs: probe for LOCALIO when v4 client reconnects to server
nfs/localio: remove redundant code and simplify LOCALIO enablement
nfs_common: add nfs_localio trace events
nfs_common: track all open nfsd_files per LOCALIO nfs_client
nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
nfsd: update percpu_ref to manage references on nfsd_net
...
Jeff Layton contributed an implementation of NFSv4.2+ attribute
delegation, as described here:
https://www.ietf.org/archive/id/draft-ietf-nfsv4-delstid-08.html
This interoperates with similar functionality introduced into the
Linux NFS client in v6.11. An attribute delegation permits an NFS
client to manage a file's mtime, rather than flushing dirty data to
the NFS server so that the file's mtime reflects the last write,
which is considerably slower.
Neil Brown contributed dynamic NFSv4.1 session slot table resizing.
This facility enables NFSD to increase or decrease the number of
slots per NFS session depending on server memory availability. More
session slots means greater parallelism.
Chuck Lever fixed a long-standing latent bug where NFSv4 COMPOUND
encoding screws up when crossing a page boundary in the encoding
buffer. This is a zero-day bug, but hitting it is rare and depends
on the NFS client implementation. The Linux NFS client does not
happen to trigger this issue.
A variety of bug fixes and other incremental improvements fill out
the list of commits in this release. Great thanks to all
contributors, reviewers, testers, and bug reporters who participated
during this development cycle.
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Merge tag 'nfsd-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd updates from Chuck Lever:
"Jeff Layton contributed an implementation of NFSv4.2+ attribute
delegation, as described here:
https://www.ietf.org/archive/id/draft-ietf-nfsv4-delstid-08.html
This interoperates with similar functionality introduced into the
Linux NFS client in v6.11. An attribute delegation permits an NFS
client to manage a file's mtime, rather than flushing dirty data to
the NFS server so that the file's mtime reflects the last write, which
is considerably slower.
Neil Brown contributed dynamic NFSv4.1 session slot table resizing.
This facility enables NFSD to increase or decrease the number of slots
per NFS session depending on server memory availability. More session
slots means greater parallelism.
Chuck Lever fixed a long-standing latent bug where NFSv4 COMPOUND
encoding screws up when crossing a page boundary in the encoding
buffer. This is a zero-day bug, but hitting it is rare and depends on
the NFS client implementation. The Linux NFS client does not happen to
trigger this issue.
A variety of bug fixes and other incremental improvements fill out the
list of commits in this release. Great thanks to all contributors,
reviewers, testers, and bug reporters who participated during this
development cycle"
* tag 'nfsd-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (42 commits)
sunrpc: Remove gss_{de,en}crypt_xdr_buf deadcode
sunrpc: Remove gss_generic_token deadcode
sunrpc: Remove unused xprt_iter_get_xprt
Revert "SUNRPC: Reduce thread wake-up rate when receiving large RPC messages"
nfsd: implement OPEN_ARGS_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION
nfsd: handle delegated timestamps in SETATTR
nfsd: add support for delegated timestamps
nfsd: rework NFS4_SHARE_WANT_* flag handling
nfsd: add support for FATTR4_OPEN_ARGUMENTS
nfsd: prepare delegation code for handing out *_ATTRS_DELEG delegations
nfsd: rename NFS4_SHARE_WANT_* constants to OPEN4_SHARE_ACCESS_WANT_*
nfsd: switch to autogenerated definitions for open_delegation_type4
nfs_common: make include/linux/nfs4.h include generated nfs4_1.h
nfsd: fix handling of delegated change attr in CB_GETATTR
SUNRPC: Document validity guarantees of the pointer returned by reserve_space
NFSD: Insulate nfsd4_encode_fattr4() from page boundaries in the encode buffer
NFSD: Insulate nfsd4_encode_secinfo() from page boundaries in the encode buffer
NFSD: Refactor nfsd4_do_encode_secinfo() again
NFSD: Insulate nfsd4_encode_readlink() from page boundaries in the encode buffer
NFSD: Insulate nfsd4_encode_read_plus_data() from page boundaries in the encode buffer
...
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Merge tag 'lsm-pr-20250121' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull lsm updates from Paul Moore:
- Improved handling of LSM "secctx" strings through lsm_context struct
The LSM secctx string interface is from an older time when only one
LSM was supported, migrate over to the lsm_context struct to better
support the different LSMs we now have and make it easier to support
new LSMs in the future.
These changes explain the Rust, VFS, and networking changes in the
diffstat.
- Only build lsm_audit.c if CONFIG_SECURITY and CONFIG_AUDIT are
enabled
Small tweak to be a bit smarter about when we build the LSM's common
audit helpers.
- Check for absurdly large policies from userspace in SafeSetID
SafeSetID policies rules are fairly small, basically just "UID:UID",
it easy to impose a limit of KMALLOC_MAX_SIZE on policy writes which
helps quiet a number of syzbot related issues. While work is being
done to address the syzbot issues through other mechanisms, this is a
trivial and relatively safe fix that we can do now.
- Various minor improvements and cleanups
A collection of improvements to the kernel selftests, constification
of some function parameters, removing redundant assignments, and
local variable renames to improve readability.
* tag 'lsm-pr-20250121' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
lockdown: initialize local array before use to quiet static analysis
safesetid: check size of policy writes
net: corrections for security_secid_to_secctx returns
lsm: rename variable to avoid shadowing
lsm: constify function parameters
security: remove redundant assignment to return variable
lsm: Only build lsm_audit.c if CONFIG_SECURITY and CONFIG_AUDIT are set
selftests: refactor the lsm `flags_overset_lsm_set_self_attr` test
binder: initialize lsm_context structure
rust: replace lsm context+len with lsm_context
lsm: secctx provider check on release
lsm: lsm_context in security_dentry_init_security
lsm: use lsm_context in security_inode_getsecctx
lsm: replace context+len with lsm_context
lsm: ensure the correct LSM context releaser
Allow clients to request getting a delegation xor an open stateid if a
delegation isn't available. This allows the client to avoid sending a
final CLOSE for the (useless) open stateid, when it is granted a
delegation.
If this flag is requested by the client and there isn't already a new
open stateid, discard the new open stateid before replying.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Allow SETATTR to handle delegated timestamps. This patch assumes that
only the delegation holder has the ability to set the timestamps in this
way, so we allow this only if the SETATTR stateid refers to a
*_ATTRS_DELEG delegation.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Add support for the delegated timestamps on write delegations. This
allows the server to proxy timestamps from the delegation holder to
other clients that are doing GETATTRs vs. the same inode.
When OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS bit is set in the OPEN
call, set the dl_type to the *_ATTRS_DELEG flavor of delegation.
Add timespec64 fields to nfs4_cb_fattr and decode the timestamps into
those. Vet those timestamps according to the delstid spec and update
the inode attrs if necessary.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The delstid draft adds new NFS4_SHARE_WANT_TYPE_MASK values that don't
fit neatly into the existing WANT_MASK or WHEN_MASK. Add a new
NFS4_SHARE_WANT_MOD_MASK value and redefine NFS4_SHARE_WANT_MASK to
include it.
Also fix the checks in nfsd4_deleg_xgrade_none_ext() to check for the
flags instead of equality, since there may be modifier flags in the
value.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Add support for FATTR4_OPEN_ARGUMENTS. This a new mechanism for the
client to discover what OPEN features the server supports.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Add some preparatory code to various functions that handle delegation
types to allow them to handle the OPEN_DELEGATE_*_ATTRS_DELEG constants.
Add helpers for detecting whether it's a read or write deleg, and
whether the attributes are delegated.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Add the OPEN4_SHARE_ACCESS_WANT constants from the nfs4.1 and delstid
draft into the nfs4_1.x file, and regenerate the headers and source
files. Do a mass renaming of NFS4_SHARE_WANT_* to
OPEN4_SHARE_ACCESS_WANT_* in the nfsd directory.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Rename the enum with the same name in include/linux/nfs4.h, add the
proper enum to nfs4_1.x and regenerate the headers and source files. Do
a mass rename of all NFS4_OPEN_DELEGATE_* to OPEN_DELEGATE_* in the nfsd
directory.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
In the long run, the NFS development community intends to autogenerate a
lot of the XDR handling code. Both the NFS client and server include
"include/linux/nfs4.hi". That file was hand-rolled, and some of the symbols
in it conflict with the autogenerated symbols.
Add a small nfs4_1.x to Documentation that currently just has the
necessary definitions for the delstid draft, and generate the relevant
header and source files. Make include/linux/nfs4.h include the generated
include/linux/sunrpc/xdrgen/nfs4_1.h and remove the conflicting
definitions from it and nfs_xdr.h.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
RFC8881, section 10.4.3 has some specific guidance as to how the
delegated change attribute should be handled. We currently don't follow
that guidance properly.
In particular, when the file is modified, the server always reports the
initial change attribute + 1. Section 10.4.3 however indicates that it
should be incremented on every GETATTR request from other clients.
Only request the change attribute until the file has been modified. If
there is an outstanding delegation, then increment the cached change
attribute on every GETATTR.
Fixes: 6487a13b5c ("NFSD: add support for CB_GETATTR callback")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This tracking enables __nfsd_file_cache_purge() to call
nfs_localio_invalidate_clients(), upon shutdown or export change, to
nfs_close_local_fh() all open nfsd_files that are still cached by the
LOCALIO nfs clients associated with nfsd_net that is being shutdown.
Now that the client must track all open nfsd_files there was more work
than necessary being done with the global nfs_uuids_lock contended.
This manifested in various RCU issues, e.g.:
hrtimer: interrupt took 47969440 ns
rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
Use nfs_uuid->lock to protect all nfs_uuid_t members, instead of
nfs_uuids_lock, once nfs_uuid_is_local() adds the client to
nn->local_clients.
Also add 'local_clients_lock' to 'struct nfsd_net' to protect
nn->local_clients. And store a pointer to spinlock in the 'list_lock'
member of nfs_uuid_t so nfs_localio_disable_client() can use it to
avoid taking the global nfs_uuids_lock.
In combination, these split out locks eliminate the use of the single
nfslocalio.c global nfs_uuids_lock in the IO paths (open and close).
Also refactored associated fs/nfs_common/nfslocalio.c methods' locking
to reduce work performed with spinlocks held in general.
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
This global spinlock protects all nfs_uuid_t relative to the global
nfs_uuids list. A later commit will split this global spinlock so
prepare by renaming this lock to reflect its intended narrow scope.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Now that LOCALIO no longer leans on NFSD's filecache for caching open
files (and instead uses NFS client-side open nfsd_file caching) there
is no need to use NFSD filecache's GC feature. Avoiding GC will speed
up nfsd_file initial opens.
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Also update Documentation/filesystems/nfs/localio.rst accordingly
and reduce the technical documentation debt that was previously
captured in that document.
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Holding a reference on nfsd_net is what is required, it was never
actually about ensuring nn->nfsd_serv available.
Move waiting for outstanding percpu references from
nfsd_destroy_serv() to nfsd_shutdown_net().
By moving it later it will be possible to invalidate localio clients
during nfsd_file_cache_shutdown_net() via __nfsd_file_cache_purge().
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Rename nfs_uuid_invalidate_one_client to nfs_localio_disable_client.
Rename nfs_uuid_invalidate_clients to nfs_localio_invalidate_clients.
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
In later a commit LOCALIO must call both nfsd_file_get and
nfsd_file_put to manage extra nfsd_file references.
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Commit ab04de60ae ("NFSD: Optimize nfsd4_encode_fattr()") replaced
the use of write_bytes_to_xdr_buf() because it's expensive and the
data items to be encoded are already properly aligned.
However, there's no guarantee that the pointer returned from
xdr_reserve_space() will still point to the correct reserved space
in the encode buffer after one or more intervening calls to
xdr_reserve_space(). It just happens to work with the current
implementation of xdr_reserve_space().
This commit effectively reverts the optimization.
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
There's no guarantee that the pointer returned from
xdr_reserve_space() will still point to the correct reserved space
in the encode buffer after one or more intervening calls to
xdr_reserve_space(). It just happens to work with the current
implementation of xdr_reserve_space().
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Extract the code that encodes the secinfo4 union data type to
clarify the logic. The removed warning is pretty well obscured and
thus probably not terribly useful.
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
There's no guarantee that the pointer returned from
xdr_reserve_space() will still point to the correct reserved space
in the encode buffer after one or more intervening calls to
xdr_reserve_space(). It just happens to work with the current
implementation of xdr_reserve_space().
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Commit eeadcb7579 ("NFSD: Simplify READ_PLUS") replaced the use of
write_bytes_to_xdr_buf(), copying what was in nfsd4_encode_read()
at the time.
However, the current code will corrupt the encoded data if the XDR
data items that are reserved early and then poked into the XDR
buffer later happen to fall on a page boundary in the XDR encoding
buffer.
__xdr_commit_encode can shift encoded data items in the encoding
buffer so that pointers returned from xdr_reserve_space() no longer
address the same part of the encoding stream.
Fixes: eeadcb7579 ("NFSD: Simplify READ_PLUS")
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Commit eeadcb7579 ("NFSD: Simplify READ_PLUS") replaced the use of
write_bytes_to_xdr_buf(), copying what was in nfsd4_encode_read()
at the time.
However, the current code will corrupt the encoded data if the XDR
data items that are reserved early and then poked into the XDR
buffer later happen to fall on a page boundary in the XDR encoding
buffer.
__xdr_commit_encode can shift encoded data items in the encoding
buffer so that pointers returned from xdr_reserve_space() no longer
address the same part of the encoding stream.
Fixes: eeadcb7579 ("NFSD: Simplify READ_PLUS")
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Commit 28d5bc468e ("NFSD: Optimize nfsd4_encode_readv()") replaced
the use of write_bytes_to_xdr_buf() because it's expensive and the
data items to be encoded are already properly aligned.
However, the current code will corrupt the encoded data if the XDR
data items that are reserved early and then poked into the XDR
buffer later happen to fall on a page boundary in the XDR encoding
buffer.
__xdr_commit_encode can shift encoded data items in the encoding
buffer so that pointers returned from xdr_reserve_space() no longer
address the same part of the encoding stream.
This isn't an issue for splice reads because the reserved encode
buffer areas must fall in the XDR buffers header for the splice to
work without error. For vectored reads, however, there is a
possibility of send buffer corruption in rare cases.
Fixes: 28d5bc468e ("NFSD: Optimize nfsd4_encode_readv()")
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
J. David reports an odd corruption of a READDIR reply sent to a
FreeBSD client.
xdr_reserve_space() has to do a special trick when the @nbytes value
requests more space than there is in the current page of the XDR
buffer.
In that case, xdr_reserve_space() returns a pointer to the start of
the next page, and then the next call to xdr_reserve_space() invokes
__xdr_commit_encode() to copy enough of the data item back into the
previous page to make that data item contiguous across the page
boundary.
But we need to be careful in the case where buffer space is reserved
early for a data item whose value will be inserted into the buffer
later.
One such caller, nfsd4_encode_operation(), reserves 8 bytes in the
encoding buffer for each COMPOUND operation. However, a READDIR
result can sometimes encode file names so that there are only 4
bytes left at the end of the current XDR buffer page (though plenty
of pages are left to handle the remaining encoding tasks).
If a COMPOUND operation follows the READDIR result (say, a GETATTR),
then nfsd4_encode_operation() will reserve 8 bytes for the op number
(9) and the op status (usually NFS4_OK). In this weird case,
xdr_reserve_space() returns a pointer to byte zero of the next buffer
page, as it assumes the data item will be copied back into place (in
the previous page) on the next call to xdr_reserve_space().
nfsd4_encode_operation() writes the op num into the buffer, then
saves the next 4-byte location for the op's status code. The next
xdr_reserve_space() call is part of GETATTR encoding, so the op num
gets copied back into the previous page, but the saved location for
the op status continues to point to the wrong spot in the current
XDR buffer page because __xdr_commit_encode() moved that data item.
After GETATTR encoding is complete, nfsd4_encode_operation() writes
the op status over the first XDR data item in the GETATTR result.
The NFS4_OK status code (0) makes it look like there are zero items
in the GETATTR's attribute bitmask.
The patch description of commit 2825a7f907 ("nfsd4: allow encoding
across page boundaries") [2014] remarks that NFSD "can't handle a
new operation starting close to the end of a page." This bug appears
to be one reason for that remark.
Reported-by: J David <j.david.lists@gmail.com>
Closes: https://lore.kernel.org/linux-nfs/3998d739-c042-46b4-8166-dbd6c5f0e804@oracle.com/T/#t
Tested-by: Rick Macklem <rmacklem@uoguelph.ca>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
We can access exp->ex_stats or exp->ex_uuid in rcu context(c_show and
e_show). All these resources should be released using kfree_rcu. Fix this
by using call_rcu, clean them all after a rcu grace period.
==================================================================
BUG: KASAN: slab-use-after-free in svc_export_show+0x362/0x430 [nfsd]
Read of size 1 at addr ff11000010fdc120 by task cat/870
CPU: 1 UID: 0 PID: 870 Comm: cat Not tainted 6.12.0-rc3+ #1
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
print_address_description.constprop.0+0x2c/0x3a0
print_report+0xb9/0x280
kasan_report+0xae/0xe0
svc_export_show+0x362/0x430 [nfsd]
c_show+0x161/0x390 [sunrpc]
seq_read_iter+0x589/0x770
seq_read+0x1e5/0x270
proc_reg_read+0xe1/0x140
vfs_read+0x125/0x530
ksys_read+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Allocated by task 830:
kasan_save_stack+0x20/0x40
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x8f/0xa0
__kmalloc_node_track_caller_noprof+0x1bc/0x400
kmemdup_noprof+0x22/0x50
svc_export_parse+0x8a9/0xb80 [nfsd]
cache_do_downcall+0x71/0xa0 [sunrpc]
cache_write_procfs+0x8e/0xd0 [sunrpc]
proc_reg_write+0xe1/0x140
vfs_write+0x1a5/0x6d0
ksys_write+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 868:
kasan_save_stack+0x20/0x40
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x37/0x50
kfree+0xf3/0x3e0
svc_export_put+0x87/0xb0 [nfsd]
cache_purge+0x17f/0x1f0 [sunrpc]
nfsd_destroy_serv+0x226/0x2d0 [nfsd]
nfsd_svc+0x125/0x1e0 [nfsd]
write_threads+0x16a/0x2a0 [nfsd]
nfsctl_transaction_write+0x74/0xa0 [nfsd]
vfs_write+0x1a5/0x6d0
ksys_write+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fixes: ae74136b4b ("SUNRPC: Allow cache lookups to use RCU protection rather than the r/w spinlock")
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
rcu_read_lock/rcu_read_unlock has already provide protection for the
pointer we will reference when we call e_show. Therefore, there is no
need to obtain a cache reference to help protect cache_head.
Additionally, the .put such as expkey_put/svc_export_put will invoke
dput, which can sleep and break rcu. Stop get cache reference to fix
them all.
Fixes: ae74136b4b ("SUNRPC: Allow cache lookups to use RCU protection rather than the r/w spinlock")
Suggested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
It helps to know what kind of callback happened that triggered the
WARN_ONCE in nfsd4_cb_done() function in diagnosing what can set
an uncommon state where both cb_status and tk_status are set at
the same time.
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If a client were to send an error to a CB_GETATTR call, the code
erronously continues to try decode past the error code. It ends
up returning BAD_XDR error to the rpc layer and then in turn
trigger a WARN_ONCE in nfsd4_cb_done() function.
Fixes: 6487a13b5c ("NFSD: add support for CB_GETATTR callback")
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Add a shrinker which frees unused slots and may ask the clients to use
fewer slots on each session.
We keep a global count of the number of freeable slots, which is the sum
of one less than the current "target" slots in all sessions in all
clients in all net-namespaces. This number is reported by the shrinker.
When the shrinker is asked to free some, we call xxx on each session in
a round-robin asking each to reduce the slot count by 1. This will
reduce the "target" so the number reported by the shrinker will reduce
immediately. The memory will only be freed later when the client
confirmed that it is no longer needed.
We use a global list of sessions and move the "head" to after the last
session that we asked to reduce, so the next callback from the shrinker
will move on to the next session. This pressure should be applied
"evenly" across all sessions over time.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reducing the number of slots in the session slot table requires
confirmation from the client. This patch adds reduce_session_slots()
which starts the process of getting confirmation, but never calls it.
That will come in a later patch.
Before we can free a slot we need to confirm that the client won't try
to use it again. This involves returning a lower cr_maxrequests in a
SEQUENCE reply and then seeing a ca_maxrequests on the same slot which
is not larger than we limit we are trying to impose. So for each slot
we need to remember that we have sent a reduced cr_maxrequests.
To achieve this we introduce a concept of request "generations". Each
time we decide to reduce cr_maxrequests we increment the generation
number, and record this when we return the lower cr_maxrequests to the
client. When a slot with the current generation reports a low
ca_maxrequests, we commit to that level and free extra slots.
We use an 16 bit generation number (64 seems wasteful) and if it cycles
we iterate all slots and reset the generation number to avoid false matches.
When we free a slot we store the seqid in the slot pointer so that it can
be restored when we reactivate the slot. The RFC can be read as
suggesting that the slot number could restart from one after a slot is
retired and reactivated, but also suggests that retiring slots is not
required. So when we reactive a slot we accept with the next seqid in
sequence, or 1.
When decoding sa_highest_slotid into maxslots we need to add 1 - this
matches how it is encoded for the reply.
se_dead is moved in struct nfsd4_session to remove a hole.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If a client ever uses the highest available slot for a given session,
attempt to allocate more slots so there is room for the client to use
them if wanted. GFP_NOWAIT is used so if there is not plenty of
free memory, failure is expected - which is what we want. It also
allows the allocation while holding a spinlock.
Each time we increase the number of slots by 20% (rounded up). This
allows fairly quick growth while avoiding excessive over-shoot.
We would expect to stablise with around 10% more slots available than
the client actually uses.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Each client now reports the number of slots allocated in each session.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Rather than guessing how much space it might be safe to use for the DRC,
simply try allocating slots and be prepared to accept failure.
The first slot for each session is allocated with GFP_KERNEL which is
unlikely to fail. Subsequent slots are allocated with the addition of
__GFP_NORETRY which is expected to fail if there isn't much free memory.
This is probably too aggressive but clears the way for adding a
shrinker interface to free extra slots when memory is tight.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Using an xarray to store session slots will make it easier to change the
number of active slots based on demand, and removes an unnecessary
limit.
To achieve good throughput with a high-latency server it can be helpful
to have hundreds of concurrent writes, which means hundreds of slots.
So increase the limit to 2048 (twice what the Linux client will
currently use). This limit is only a sanity check, not a hard limit.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Now that the connection limit only apply to unconfirmed connections,
there is no need to configure it. So remove all the configuration and
fix the number of unconfirmed connections as always 64 - which is
now given a name: XPT_MAX_TMP_CONN
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The heuristic for limiting the number of incoming connections to nfsd
currently uses sv_nrthreads - allowing more connections if more threads
were configured.
A future patch will allow number of threads to grow dynamically so that
there will be no need to configure sv_nrthreads. So we need a different
solution for limiting connections.
It isn't clear what problem is solved by limiting connections (as
mentioned in a code comment) but the most likely problem is a connection
storm - many connections that are not doing productive work. These will
be closed after about 6 minutes already but it might help to slow down a
storm.
This patch adds a per-connection flag XPT_PEER_VALID which indicates
that the peer has presented a filehandle for which it has some sort of
access. i.e the peer is known to be trusted in some way. We now only
count connections which have NOT been determined to be valid. There
should be relative few of these at any given time.
If the number of non-validated peer exceed a limit - currently 64 - we
close the oldest non-validated peer to avoid having too many of these
useless connections.
Note that this patch significantly changes the meaning of the various
configuration parameters for "max connections". The next patch will
remove all of these.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Get rid of the nfsd4_legacy_tracking_ops->init() call in
check_for_legacy_methods(). That will be handled in the caller
(nfsd4_client_tracking_init()). Otherwise, we'll wind up calling
nfsd4_legacy_tracking_ops->init() twice, and the second time we'll
trigger the BUG_ON() in nfsd4_init_recdir().
Fixes: 74fd48739d ("nfsd: new Kconfig option for legacy client tracking")
Reported-by: Jur van der Burg <jur@avtware.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219580
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
@sb should have been removed by commit 7e64c5bc49 ("NLM/NFSD: Fix
lock notifications for async-capable filesystems").
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The wake_up_var interface is fragile as barriers are sometimes needed.
There are now new interfaces so that most wake-ups can use an interface
that is guaranteed to have all barriers needed.
This patch changes the wake up on cl_cb_inflight to use
atomic_dec_and_wake_up().
It also changes the wake up on rp_locked to use store_release_wake_up().
This involves changing rp_locked from atomic_t to int.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Since commit e56dc9e294 ("nfsd: remove fault injection code") remove
all nfsd_recall_delegations codes,
we don't need trace_nfsd_deleg_recall any more.
Signed-off-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
- Revert one v6.13 fix at the author's request
- Fix a minor problem with recent NFSv4.2 COPY enhancements
- Fix an NFSv4.0 callback bug introduced in the v6.13 merge window
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Merge tag 'nfsd-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
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: 1e02c641c3 ("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 aa0ebd21df
("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: aa0ebd21df ("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 f8c989a0c8.
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: f8c989a0c8 ("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>
Change the security_inode_getsecctx() interface to fill a lsm_context
structure instead of data and length pointers. This provides
the information about which LSM created the context so that
security_release_secctx() can use the correct hook.
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Add a new lsm_context data structure to hold all the information about a
"security context", including the string, its size and which LSM allocated
the string. The allocation information is necessary because LSMs have
different policies regarding the lifecycle of these strings. SELinux
allocates and destroys them on each use, whereas Smack provides a pointer
to an entry in a list that never goes away.
Update security_release_secctx() to use the lsm_context instead of a
(char *, len) pair. Change its callers to do likewise. The LSMs
supporting this hook have had comments added to remind the developer
that there is more work to be done.
The BPF security module provides all LSM hooks. While there has yet to
be a known instance of a BPF configuration that uses security contexts,
the possibility is real. In the existing implementation there is
potential for multiple frees in that case.
Cc: linux-integrity@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: audit@vger.kernel.org
Cc: netfilter-devel@vger.kernel.org
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: linux-nfs@vger.kernel.org
Cc: Todd Kjos <tkjos@google.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
The code already got rid of the extra reference count from the old
version of override_creds().
Link: https://lore.kernel.org/r/20241125-work-cred-v2-28-68b9d38bb5b2@kernel.org
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The code already got rid of the extra reference count from the old
version of override_creds().
Link: https://lore.kernel.org/r/20241125-work-cred-v2-16-68b9d38bb5b2@kernel.org
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The code already got rid of the extra reference count from the old
version of override_creds().
Link: https://lore.kernel.org/r/20241125-work-cred-v2-15-68b9d38bb5b2@kernel.org
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Convert all calls to revert_creds() over to explicitly dropping
reference counts in preparation for converting revert_creds() to
revert_creds_light() semantics.
Link: https://lore.kernel.org/r/20241125-work-cred-v2-3-68b9d38bb5b2@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Convert all callers from override_creds() to
override_creds_light(get_new_cred()) in preparation of making
override_creds() not take a separate reference at all.
Link: https://lore.kernel.org/r/20241125-work-cred-v2-1-68b9d38bb5b2@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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.
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Merge tag 'nfsd-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
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
...
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.
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Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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>
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>
Keep async copy state alive for a few lease cycles after the copy
completes so that OFFLOAD_STATUS returns something meaningful.
This means that NFSD's client shutdown processing needs to purge
any of this state that happens to be waiting to die.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
RFC 7862 Section 4.8 states:
> A copy offload stateid will be valid until either (A) the client
> or server restarts or (B) the client returns the resource by
> issuing an OFFLOAD_CANCEL operation or the client replies to a
> CB_OFFLOAD operation.
Instead of releasing async copy state when the CB_OFFLOAD callback
completes, now let it live until the next laundromat run after the
callback completes.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently __destroy_client() consults the nfs4_client's async_copies
list to determine whether there are ongoing async COPY operations.
However, NFSD now keeps copy state in that list even when the
async copy has completed, to enable OFFLOAD_STATUS to find the
COPY results for a while after the COPY has completed.
DESTROY_CLIENTID should not be blocked if the client's async_copies
list contains state for only completed copy operations.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
RFC 7862 permits callback services to respond to CB_OFFLOAD with
NFS4ERR_DELAY. Currently NFSD drops the CB_OFFLOAD in that case.
To improve the reliability of COPY offload, NFSD should rather send
another CB_OFFLOAD completion notification.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
RFC 7862 Section 4.8 states:
> A copy offload stateid will be valid until either (A) the client
> or server restarts or (B) the client returns the resource by
> issuing an OFFLOAD_CANCEL operation or the client replies to a
> CB_OFFLOAD operation.
Currently, NFSD purges the metadata for an async COPY operation as
soon as the CB_OFFLOAD callback has been sent. It does not wait even
for the client's CB_OFFLOAD response, as the paragraph above
suggests that it should.
This makes the OFFLOAD_STATUS operation ineffective during the
window between the completion of an asynchronous COPY and the
server's receipt of the corresponding CB_OFFLOAD response. This is
important if, for example, the client responds with NFS4ERR_DELAY,
or the transport is lost before the server receives the response. A
client might use OFFLOAD_STATUS to query the server about the still
pending asynchronous COPY, but NFSD will respond to OFFLOAD_STATUS
as if it had never heard of the presented copy stateid.
This patch starts to address this issue by extending the lifetime of
struct nfsd4_copy at least until the server has seen the client's
CB_OFFLOAD response, or the CB_OFFLOAD has timed out.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd4_shutdown_copy() is just this:
while ((copy = nfsd4_get_copy(clp)) != NULL)
nfsd4_stop_copy(copy);
nfsd4_get_copy() bumps @copy's reference count, preventing
nfsd4_stop_copy() from releasing @copy.
A while loop like this usually works by removing the first element
of the list, but neither nfsd4_get_copy() nor nfsd4_stop_copy()
alters the async_copies list.
Best I can tell, then, is that nfsd4_shutdown_copy() continues to
loop until other threads manage to remove all the items from this
list. The spinning loop blocks shutdown until these items are gone.
Possibly the reason we haven't seen this issue in the field is
because client_has_state() prevents __destroy_client() from calling
nfsd4_shutdown_copy() if there are any items on this list. In a
subsequent patch I plan to remove that restriction.
Fixes: e0639dc580 ("NFSD introduce async copy feature")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
While this holds the flags from the CREATE_SESSION request, nothing
ever consults them. The only flag used is NFS4_SESSION_DEAD. Make it a
simple bool instead.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This field is written and is never consulted again. Remove it.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
refcount_t, by design, checks for unwanted situations and provides
warnings. It is rarely useful to have explicit warnings with refcount
usage.
In this case we have an explicit warning if a refcount_t reaches zero
when decremented. Simply using refcount_dec() will provide a similar
warning and also mark the refcount_t as saturated to avoid any possible
use-after-free.
This patch drops the warning and uses refcount_dec() instead of
refcount_dec_and_test().
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Failing OP_SETCLIENTID or OP_EXCHANGE_ID should only happen if there is
memory allocation failure. Putting a hard limit on the number of
clients is not really helpful as it will either happen too early and
prevent clients that the server can easily handle, or too late and
allow clients when the server is swamped.
The calculated limit is still useful for expiring courtesy clients where
there are "too many" clients, but it shouldn't prevent the creation of
active clients.
Testing of lots of clients against small-mem servers reports repeated
NFS4ERR_DELAY responses which doesn't seem helpful. There may have been
reports of similar problems in production use.
Also remove an outdated comment - we do use a slab cache.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The last reference for `cache_head` can be reduced to zero in `c_show`
and `e_show`(using `rcu_read_lock` and `rcu_read_unlock`). Consequently,
`svc_export_put` and `expkey_put` will be invoked, leading to two
issues:
1. The `svc_export_put` will directly free ex_uuid. However,
`e_show`/`c_show` will access `ex_uuid` after `cache_put`, which can
trigger a use-after-free issue, shown below.
==================================================================
BUG: KASAN: slab-use-after-free in svc_export_show+0x362/0x430 [nfsd]
Read of size 1 at addr ff11000010fdc120 by task cat/870
CPU: 1 UID: 0 PID: 870 Comm: cat Not tainted 6.12.0-rc3+ #1
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
print_address_description.constprop.0+0x2c/0x3a0
print_report+0xb9/0x280
kasan_report+0xae/0xe0
svc_export_show+0x362/0x430 [nfsd]
c_show+0x161/0x390 [sunrpc]
seq_read_iter+0x589/0x770
seq_read+0x1e5/0x270
proc_reg_read+0xe1/0x140
vfs_read+0x125/0x530
ksys_read+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Allocated by task 830:
kasan_save_stack+0x20/0x40
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x8f/0xa0
__kmalloc_node_track_caller_noprof+0x1bc/0x400
kmemdup_noprof+0x22/0x50
svc_export_parse+0x8a9/0xb80 [nfsd]
cache_do_downcall+0x71/0xa0 [sunrpc]
cache_write_procfs+0x8e/0xd0 [sunrpc]
proc_reg_write+0xe1/0x140
vfs_write+0x1a5/0x6d0
ksys_write+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 868:
kasan_save_stack+0x20/0x40
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x37/0x50
kfree+0xf3/0x3e0
svc_export_put+0x87/0xb0 [nfsd]
cache_purge+0x17f/0x1f0 [sunrpc]
nfsd_destroy_serv+0x226/0x2d0 [nfsd]
nfsd_svc+0x125/0x1e0 [nfsd]
write_threads+0x16a/0x2a0 [nfsd]
nfsctl_transaction_write+0x74/0xa0 [nfsd]
vfs_write+0x1a5/0x6d0
ksys_write+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
2. We cannot sleep while using `rcu_read_lock`/`rcu_read_unlock`.
However, `svc_export_put`/`expkey_put` will call path_put, which
subsequently triggers a sleeping operation due to the following
`dput`.
=============================
WARNING: suspicious RCU usage
5.10.0-dirty #141 Not tainted
-----------------------------
...
Call Trace:
dump_stack+0x9a/0xd0
___might_sleep+0x231/0x240
dput+0x39/0x600
path_put+0x1b/0x30
svc_export_put+0x17/0x80
e_show+0x1c9/0x200
seq_read_iter+0x63f/0x7c0
seq_read+0x226/0x2d0
vfs_read+0x113/0x2c0
ksys_read+0xc9/0x170
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x67/0xd1
Fix these issues by using `rcu_work` to help release
`svc_expkey`/`svc_export`. This approach allows for an asynchronous
context to invoke `path_put` and also facilitates the freeing of
`uuid/exp/key` after an RCU grace period.
Fixes: 9ceddd9da1 ("knfsd: Allow lockless lookups of the exports")
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The function `e_show` was called with protection from RCU. This only
ensures that `exp` will not be freed. Therefore, the reference count for
`exp` can drop to zero, which will trigger a refcount use-after-free
warning when `exp_get` is called. To resolve this issue, use
`cache_get_rcu` to ensure that `exp` remains active.
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 3 PID: 819 at lib/refcount.c:25
refcount_warn_saturate+0xb1/0x120
CPU: 3 UID: 0 PID: 819 Comm: cat Not tainted 6.12.0-rc3+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
RIP: 0010:refcount_warn_saturate+0xb1/0x120
...
Call Trace:
<TASK>
e_show+0x20b/0x230 [nfsd]
seq_read_iter+0x589/0x770
seq_read+0x1e5/0x270
vfs_read+0x125/0x530
ksys_read+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fixes: bf18f163e8 ("NFSD: Using exp_get for export getting")
Cc: stable@vger.kernel.org # 4.20+
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
It's only current caller already length-checks the string, but let's
be safe.
Fixes: 0964a3d3f1 ("[PATCH] knfsd: nfsd4 reboot dirname fix")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up. The computed value of @p is saved each time through the
loop but is never used.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up. The result of "*p++" is saved, but is not used before it
is overwritten. The result of xdr_encode_opaque() is saved each
time through the loop but is never used.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
@ses is initialized to NULL. If __nfsd4_find_backchannel() finds no
available backchannel session, setup_callback_client() will try to
dereference @ses and segfault.
Fixes: dcbeaa68db ("nfsd4: allow backchannel recovery")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
fh_size is an unsigned int, thus it can never be less than 0.
Fixes: d8b26071e6 ("NFSD: simplify struct nfsfh")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up. AFAICT, there is no way to reach the out_free_conn label
with @old set to a non-NULL value, so the expire_client(old) call
is never reached and can be removed.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
NFSD_MAY_LOCK means a few different things.
- it means that GSS is not required.
- it means that with NFSEXP_NOAUTHNLM, authentication is not required
- it means that OWNER_OVERRIDE is allowed.
None of these are specific to locking, they are specific to the NLM
protocol.
So:
- rename to NFSD_MAY_NLM
- set NFSD_MAY_OWNER_OVERRIDE and NFSD_MAY_BYPASS_GSS in nlm_fopen()
so that NFSD_MAY_NLM doesn't need to imply these.
- move the test on NFSEXP_NOAUTHNLM out of nfsd_permission() and
into fh_verify where other special-case tests on the MAY flags
happen. nfsd_permission() can be called from other places than
fh_verify(), but none of these will have NFSD_MAY_NLM.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
NFSv4 LOCK operations should not avoid the set of authorization
checks that apply to all other NFSv4 operations. Also, the
"no_auth_nlm" export option should apply only to NLM LOCK requests.
It's not necessary or sensible to apply it to NFSv4 LOCK operations.
Instead, set no permission bits when calling fh_verify(). Subsequent
stateid processing handles authorization checks.
Reported-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Since SLOB was removed and since
commit 6c6c47b063 ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"),
it is not necessary to use call_rcu when the callback only performs
kmem_cache_free. Use kfree_rcu() directly.
The changes were made using Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently NFSD_MAY_BYPASS_GSS and NFSD_MAY_BYPASS_GSS_ON_ROOT do not bypass
only GSS, but bypass any method. This is a problem specially for NFS3
AUTH_NULL-only exports.
The purpose of NFSD_MAY_BYPASS_GSS_ON_ROOT is described in RFC 2623,
section 2.3.2, to allow mounting NFS2/3 GSS-only export without
authentication. So few procedures which do not expose security risk used
during mount time can be called also with AUTH_NONE or AUTH_SYS, to allow
client mount operation to finish successfully.
The problem with current implementation is that for AUTH_NULL-only exports,
the NFSD_MAY_BYPASS_GSS_ON_ROOT is active also for NFS3 AUTH_UNIX mount
attempts which confuse NFS3 clients, and make them think that AUTH_UNIX is
enabled and is working. Linux NFS3 client never switches from AUTH_UNIX to
AUTH_NONE on active mount, which makes the mount inaccessible.
Fix the NFSD_MAY_BYPASS_GSS and NFSD_MAY_BYPASS_GSS_ON_ROOT implementation
and really allow to bypass only exports which have enabled some real
authentication (GSS, TLS, or any other).
The result would be: For AUTH_NULL-only export if client attempts to do
mount with AUTH_UNIX flavor then it will receive access errors, which
instruct client that AUTH_UNIX flavor is not usable and will either try
other auth flavor (AUTH_NULL if enabled) or fails mount procedure.
Similarly if client attempt to do mount with AUTH_NULL flavor and only
AUTH_UNIX flavor is enabled then the client will receive access error.
This should fix problems with AUTH_NULL-only or AUTH_UNIX-only exports if
client attempts to mount it with other auth flavor (e.g. with AUTH_NULL for
AUTH_UNIX-only export, or with AUTH_UNIX for AUTH_NULL-only export).
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
NFSv4.1 OP_EXCHANGE_ID response from server may contain server
implementation details (domain, name and build time) in optional
nfs_impl_id4 field. Currently nfsd does not fill this field.
Send these information in NFSv4.1 OP_EXCHANGE_ID response. Fill them with
the same values as what is Linux NFSv4.1 client doing. Domain is hardcoded
to "kernel.org", name is composed in the same way as "uname -srvm" output
and build time is hardcoded to zeros.
NFSv4.1 client and server implementation fields are useful for statistic
purposes or for identifying type of clients and servers.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Turn nfsd_compound_encode_err tracepoint into a class and add a new
nfsd_compound_op_err tracepoint.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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Merge tag 'vfs-6.13.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Features:
- Fixup and improve NLM and kNFSD file lock callbacks
Last year both GFS2 and OCFS2 had some work done to make their
locking more robust when exported over NFS. Unfortunately, part of
that work caused both NLM (for NFS v3 exports) and kNFSD (for
NFSv4.1+ exports) to no longer send lock notifications to clients
This in itself is not a huge problem because most NFS clients will
still poll the server in order to acquire a conflicted lock
It's important for NLM and kNFSD that they do not block their
kernel threads inside filesystem's file_lock implementations
because that can produce deadlocks. We used to make sure of this by
only trusting that posix_lock_file() can correctly handle blocking
lock calls asynchronously, so the lock managers would only setup
their file_lock requests for async callbacks if the filesystem did
not define its own lock() file operation
However, when GFS2 and OCFS2 grew the capability to correctly
handle blocking lock requests asynchronously, they started
signalling this behavior with EXPORT_OP_ASYNC_LOCK, and the check
for also trusting posix_lock_file() was inadvertently dropped, so
now most filesystems no longer produce lock notifications when
exported over NFS
Fix this by using an fop_flag which greatly simplifies the problem
and grooms the way for future uses by both filesystems and lock
managers alike
- Add a sysctl to delete the dentry when a file is removed instead of
making it a negative dentry
Commit 681ce86235 ("vfs: Delete the associated dentry when
deleting a file") introduced an unconditional deletion of the
associated dentry when a file is removed. However, this led to
performance regressions in specific benchmarks, such as
ilebench.sum_operations/s, prompting a revert in commit
4a4be1ad3a ("Revert "vfs: Delete the associated dentry when
deleting a file""). This reintroduces the concept conditionally
through a sysctl
- Expand the statmount() system call:
* Report the filesystem subtype in a new fs_subtype field to
e.g., report fuse filesystem subtypes
* Report the superblock source in a new sb_source field
* Add a new way to return filesystem specific mount options in an
option array that returns filesystem specific mount options
separated by zero bytes and unescaped. This allows caller's to
retrieve filesystem specific mount options and immediately pass
them to e.g., fsconfig() without having to unescape or split
them
* Report security (LSM) specific mount options in a separate
security option array. We don't lump them together with
filesystem specific mount options as security mount options are
generic and most users aren't interested in them
The format is the same as for the filesystem specific mount
option array
- Support relative paths in fsconfig()'s FSCONFIG_SET_STRING command
- Optimize acl_permission_check() to avoid costly {g,u}id ownership
checks if possible
- Use smp_mb__after_spinlock() to avoid full smp_mb() in evict()
- Add synchronous wakeup support for ep_poll_callback.
Currently, epoll only uses wake_up() to wake up task. But sometimes
there are epoll users which want to use the synchronous wakeup flag
to give a hint to the scheduler, e.g., the Android binder driver.
So add a wake_up_sync() define, and use wake_up_sync() when sync is
true in ep_poll_callback()
Fixes:
- Fix kernel documentation for inode_insert5() and iget5_locked()
- Annotate racy epoll check on file->f_ep
- Make F_DUPFD_QUERY associative
- Avoid filename buffer overrun in initramfs
- Don't let statmount() return empty strings
- Add a cond_resched() to dump_user_range() to avoid hogging the CPU
- Don't query the device logical blocksize multiple times for hfsplus
- Make filemap_read() check that the offset is positive or zero
Cleanups:
- Various typo fixes
- Cleanup wbc_attach_fdatawrite_inode()
- Add __releases annotation to wbc_attach_and_unlock_inode()
- Add hugetlbfs tracepoints
- Fix various vfs kernel doc parameters
- Remove obsolete TODO comment from io_cancel()
- Convert wbc_account_cgroup_owner() to take a folio
- Fix comments for BANDWITH_INTERVAL and wb_domain_writeout_add()
- Reorder struct posix_acl to save 8 bytes
- Annotate struct posix_acl with __counted_by()
- Replace one-element array with flexible array member in freevxfs
- Use idiomatic atomic64_inc_return() in alloc_mnt_ns()"
* tag 'vfs-6.13.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
statmount: retrieve security mount options
vfs: make evict() use smp_mb__after_spinlock instead of smp_mb
statmount: add flag to retrieve unescaped options
fs: add the ability for statmount() to report the sb_source
writeback: wbc_attach_fdatawrite_inode out of line
writeback: add a __releases annoation to wbc_attach_and_unlock_inode
fs: add the ability for statmount() to report the fs_subtype
fs: don't let statmount return empty strings
fs:aio: Remove TODO comment suggesting hash or array usage in io_cancel()
hfsplus: don't query the device logical block size multiple times
freevxfs: Replace one-element array with flexible array member
fs: optimize acl_permission_check()
initramfs: avoid filename buffer overrun
fs/writeback: convert wbc_account_cgroup_owner to take a folio
acl: Annotate struct posix_acl with __counted_by()
acl: Realign struct posix_acl to save 8 bytes
epoll: Add synchronous wakeup support for ep_poll_callback
coredump: add cond_resched() to dump_user_range
mm/page-writeback.c: Fix comment of wb_domain_writeout_add()
mm/page-writeback.c: Update comment for BANDWIDTH_INTERVAL
...
Now isolation no longer takes the list_lru global node lock, only use the
per-cgroup lock instead. And this lock is inside the list_lru_one being
walked, no longer needed to pass the lock explicitly.
Link: https://lkml.kernel.org/r/20241104175257.60853-7-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently we pass back the size and whether it has been modified, but
those just mirror values tracked inside the delegation. In a later
patch, we'll need to get at the timestamps in the delegation too, so
just pass back a reference to the write delegation, and use that to
properly override values in the iattr.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
We already have a slot for this in the kstat structure. Just overwrite
that instead of keeping a copy.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This is always the same value, and in a later patch we're going to need
to set bits in WORD2. We can simplify this code and save a little space
in the delegation too. Just hardcode the bitmap in the callback encode
function.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The inode that nfs4_open_delegation() passes to this function is
wrong, which throws off the result. The inode will end up getting a
directory-style change attr instead of a regular-file-style one.
Fix up nfs4_delegation_stat() to fetch STATX_MODE, and then drop the
inode parameter from nfsd4_change_attribute(), since it's no longer
needed.
Fixes: c5967721e1 ("NFSD: handle GETATTR conflict with write delegation")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: Commit 65294c1f2c ("nfsd: add a new struct file caching
facility to nfsd") moved the fh_verify() call site out of
nfsd_open(). That was the only user of nfsd_open's @rqstp parameter,
so that parameter can be removed.
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The posix_acl_entry pointer pe is already initialized by the
FOREACH_ACL_ENTRY() macro. Remove the unnecessary initialization.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If the tag length is >= U32_MAX - 3 then the "length + 4" addition
can result in an integer overflow. Address this by splitting the
decoding into several steps so that decode_cb_compound4res() does
not have to perform arithmetic on the unsafe length value.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
I noticed that recently, simple operations like "make" started
failing on NFSv3 mounts of ext4 exports. Network capture shows that
READDIRPLUS operated correctly but READDIR failed with
NFS3ERR_INVAL. The vfs_llseek() call returned EINVAL when it is
passed a non-zero starting directory cookie.
I bisected to commit c689bdd3bf ("nfsd: further centralize
protocol version checks.").
Turns out that nfsd3_proc_readdir() does not call fh_verify() before
it calls nfsd_readdir(), so the new fhp->fh_64bit_cookies boolean is
not set properly. This leaves the NFSD_MAY_64BIT_COOKIE unset when
the directory is opened.
For ext4, this causes the wrong "max file size" value to be used
when sanity checking the incoming directory cookie (which is a seek
offset value).
The fhp->fh_64bit_cookies boolean is /always/ properly initialized
after nfsd_open() returns. There doesn't seem to be a reason for the
generic NFSD open helper to handle the f_mode fix-up for
directories, so just move that to the one caller that tries to open
an S_IFDIR with NFSD_MAY_64BIT_COOKIE.
Suggested-by: NeilBrown <neilb@suse.de>
Fixes: c689bdd3bf ("nfsd: further centralize protocol version checks.")
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The error flow in nfsd4_copy() calls cleanup_async_copy(), which
already decrements nn->pending_async_copies.
Reported-by: Olga Kornievskaia <okorniev@redhat.com>
Fixes: aadc3bbea1 ("NFSD: Limit the number of concurrent async COPY operations")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Ensure the refcount and async_copies fields are initialized early.
cleanup_async_copy() will reference these fields if an error occurs
in nfsd4_copy(). If they are not correctly initialized, at the very
least, a refcount underflow occurs.
Reported-by: Olga Kornievskaia <okorniev@redhat.com>
Fixes: aadc3bbea1 ("NFSD: Limit the number of concurrent async COPY operations")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
- Fix a couple of use-after-free bugs
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Merge tag 'nfsd-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd fixes from Chuck Lever:
- Fix a couple of use-after-free bugs
* tag 'nfsd-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
nfsd: cancel nfsd_shrinker_work using sync mode in nfs4_state_shutdown_net
nfsd: fix race between laundromat and free_stateid
In the normal case, when we excute `echo 0 > /proc/fs/nfsd/threads`, the
function `nfs4_state_destroy_net` in `nfs4_state_shutdown_net` will
release all resources related to the hashed `nfs4_client`. If the
`nfsd_client_shrinker` is running concurrently, the `expire_client`
function will first unhash this client and then destroy it. This can
lead to the following warning. Additionally, numerous use-after-free
errors may occur as well.
nfsd_client_shrinker echo 0 > /proc/fs/nfsd/threads
expire_client nfsd_shutdown_net
unhash_client ...
nfs4_state_shutdown_net
/* won't wait shrinker exit */
/* cancel_work(&nn->nfsd_shrinker_work)
* nfsd_file for this /* won't destroy unhashed client1 */
* client1 still alive nfs4_state_destroy_net
*/
nfsd_file_cache_shutdown
/* trigger warning */
kmem_cache_destroy(nfsd_file_slab)
kmem_cache_destroy(nfsd_file_mark_slab)
/* release nfsd_file and mark */
__destroy_client
====================================================================
BUG nfsd_file (Not tainted): Objects remaining in nfsd_file on
__kmem_cache_shutdown()
--------------------------------------------------------------------
CPU: 4 UID: 0 PID: 764 Comm: sh Not tainted 6.12.0-rc3+ #1
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+0x1a5/0x6d0
ksys_write+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
====================================================================
BUG nfsd_file_mark (Tainted: G B W ): Objects remaining
nfsd_file_mark on __kmem_cache_shutdown()
--------------------------------------------------------------------
dump_stack_lvl+0x53/0x70
slab_err+0xb0/0xf0
__kmem_cache_shutdown+0x15c/0x310
kmem_cache_destroy+0x66/0x160
nfsd_file_cache_shutdown+0xc8/0x210 [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+0x1a5/0x6d0
ksys_write+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
To resolve this issue, cancel `nfsd_shrinker_work` using synchronous
mode in nfs4_state_shutdown_net.
Fixes: 7c24fa2250 ("NFSD: replace delayed_work with work_struct for nfsd_client_shrinker")
Signed-off-by: Yang Erkun <yangerkun@huaweicloud.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
There is a race between laundromat handling of revoked delegations
and a client sending free_stateid operation. Laundromat thread
finds that delegation has expired and needs to be revoked so it
marks the delegation stid revoked and it puts it on a reaper list
but then it unlock the state lock and the actual delegation revocation
happens without the lock. Once the stid is marked revoked a racing
free_stateid processing thread does the following (1) it calls
list_del_init() which removes it from the reaper list and (2) frees
the delegation stid structure. The laundromat thread ends up not
calling the revoke_delegation() function for this particular delegation
but that means it will no release the lock lease that exists on
the file.
Now, a new open for this file comes in and ends up finding that
lease list isn't empty and calls nfsd_breaker_owns_lease() which ends
up trying to derefence a freed delegation stateid. Leading to the
followint use-after-free KASAN warning:
kernel: ==================================================================
kernel: BUG: KASAN: slab-use-after-free in nfsd_breaker_owns_lease+0x140/0x160 [nfsd]
kernel: Read of size 8 at addr ffff0000e73cd0c8 by task nfsd/6205
kernel:
kernel: CPU: 2 UID: 0 PID: 6205 Comm: nfsd Kdump: loaded Not tainted 6.11.0-rc7+ #9
kernel: Hardware name: Apple Inc. Apple Virtualization Generic Platform, BIOS 2069.0.0.0.0 08/03/2024
kernel: Call trace:
kernel: dump_backtrace+0x98/0x120
kernel: show_stack+0x1c/0x30
kernel: dump_stack_lvl+0x80/0xe8
kernel: print_address_description.constprop.0+0x84/0x390
kernel: print_report+0xa4/0x268
kernel: kasan_report+0xb4/0xf8
kernel: __asan_report_load8_noabort+0x1c/0x28
kernel: nfsd_breaker_owns_lease+0x140/0x160 [nfsd]
kernel: nfsd_file_do_acquire+0xb3c/0x11d0 [nfsd]
kernel: nfsd_file_acquire_opened+0x84/0x110 [nfsd]
kernel: nfs4_get_vfs_file+0x634/0x958 [nfsd]
kernel: nfsd4_process_open2+0xa40/0x1a40 [nfsd]
kernel: nfsd4_open+0xa08/0xe80 [nfsd]
kernel: nfsd4_proc_compound+0xb8c/0x2130 [nfsd]
kernel: nfsd_dispatch+0x22c/0x718 [nfsd]
kernel: svc_process_common+0x8e8/0x1960 [sunrpc]
kernel: svc_process+0x3d4/0x7e0 [sunrpc]
kernel: svc_handle_xprt+0x828/0xe10 [sunrpc]
kernel: svc_recv+0x2cc/0x6a8 [sunrpc]
kernel: nfsd+0x270/0x400 [nfsd]
kernel: kthread+0x288/0x310
kernel: ret_from_fork+0x10/0x20
This patch proposes a fixed that's based on adding 2 new additional
stid's sc_status values that help coordinate between the laundromat
and other operations (nfsd4_free_stateid() and nfsd4_delegreturn()).
First to make sure, that once the stid is marked revoked, it is not
removed by the nfsd4_free_stateid(), the laundromat take a reference
on the stateid. Then, coordinating whether the stid has been put
on the cl_revoked list or we are processing FREE_STATEID and need to
make sure to remove it from the list, each check that state and act
accordingly. If laundromat has added to the cl_revoke list before
the arrival of FREE_STATEID, then nfsd4_free_stateid() knows to remove
it from the list. If nfsd4_free_stateid() finds that operations arrived
before laundromat has placed it on cl_revoke list, it marks the state
freed and then laundromat will no longer add it to the list.
Also, for nfsd4_delegreturn() when looking for the specified stid,
we need to access stid that are marked removed or freeable, it means
the laundromat has started processing it but hasn't finished and this
delegreturn needs to return nfserr_deleg_revoked and not
nfserr_bad_stateid. The latter will not trigger a FREE_STATEID and the
lack of it will leave this stid on the cl_revoked list indefinitely.
Fixes: 2d4a532d38 ("nfsd: ensure that clp->cl_revoked list is protected by clp->cl_lock")
CC: stable@vger.kernel.org
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Localio Bugfixes:
* Remove duplicated include in localio.c
* Fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()
* Fix Kconfig for NFS_COMMON_LOCALIO_SUPPORT
* Fix nfsd_file tracepoints to handle NULL rqstp pointers
Other Bugfixes:
* Fix program selection loop in svc_process_common
* Fix integer overflow in decode_rc_list()
* Prevent NULL-pointer dereference in nfs42_complete_copies()
* Fix CB_RECALL performance issues when using a large number of delegations
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Merge tag 'nfs-for-6.12-2' of git://git.linux-nfs.org/projects/anna/linux-nfs
Pull NFS client fixes from Anna Schumaker:
"Localio Bugfixes:
- remove duplicated include in localio.c
- fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()
- fix Kconfig for NFS_COMMON_LOCALIO_SUPPORT
- fix nfsd_file tracepoints to handle NULL rqstp pointers
Other Bugfixes:
- fix program selection loop in svc_process_common
- fix integer overflow in decode_rc_list()
- prevent NULL-pointer dereference in nfs42_complete_copies()
- fix CB_RECALL performance issues when using a large number of
delegations"
* tag 'nfs-for-6.12-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
NFS: remove revoked delegation from server's delegation list
nfsd/localio: fix nfsd_file tracepoints to handle NULL rqstp
nfs_common: fix Kconfig for NFS_COMMON_LOCALIO_SUPPORT
nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()
NFSv4: Prevent NULL-pointer dereference in nfs42_complete_copies()
SUNRPC: Fix integer overflow in decode_rc_list()
sunrpc: fix prog selection loop in svc_process_common
nfs: Remove duplicated include in localio.c
- Fix NFSD bring-up / shutdown
- Fix a UAF when releasing a stateid
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Merge tag 'nfsd-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd fixes from Chuck Lever:
- Fix NFSD bring-up / shutdown
- Fix a UAF when releasing a stateid
* tag 'nfsd-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
nfsd: fix possible badness in FREE_STATEID
nfsd: nfsd_destroy_serv() must call svc_destroy() even if nfsd_startup_net() failed
NFSD: Mark filecache "down" if init fails
When multiple FREE_STATEIDs are sent for the same delegation stateid,
it can lead to a possible either use-after-free or counter refcount
underflow errors.
In nfsd4_free_stateid() under the client lock we find a delegation
stateid, however the code drops the lock before calling nfs4_put_stid(),
that allows another FREE_STATE to find the stateid again. The first one
will proceed to then free the stateid which leads to either
use-after-free or decrementing already zeroed counter.
Fixes: 3f29cc82a8 ("nfsd: split sc_status out of sc_type")
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Otherwise nfsd_file_acquire, nfsd_file_insert_err, and
nfsd_file_cons_err will hit a NULL pointer when they are enabled and
LOCALIO used.
Example trace output (note xid is 0x0 and LOCALIO flag set):
nfsd_file_acquire: xid=0x0 inode=0000000069a1b2e7
may_flags=WRITE|LOCALIO ref=1 nf_flags=HASHED|GC nf_may=WRITE
nf_file=0000000070123234 status=0
Fixes: c63f0e48fe ("nfsd: add nfsd_file_acquire_local()")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Add nfs_to_nfsd_file_put_local() interface to fix race with nfsd
module unload. Similarly, use RCU around nfs_open_local_fh()'s error
path call to nfs_to->nfsd_serv_put(). Holding RCU ensures that NFS
will safely _call and return_ from its nfs_to calls into the NFSD
functions nfsd_file_put_local() and nfsd_serv_put().
Otherwise, if RCU isn't used then there is a narrow window when NFS's
reference for the nfsd_file and nfsd_serv are dropped and the NFSD
module could be unloaded, which could result in a crash from the
return instruction for either nfs_to->nfsd_file_put_local() or
nfs_to->nfsd_serv_put().
Reported-by: NeilBrown <neilb@suse.de>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
[Syzbot reported]
WARNING: possible circular locking dependency detected
6.11.0-rc4-syzkaller-00019-gb311c1b497e5 #0 Not tainted
------------------------------------------------------
kswapd0/78 is trying to acquire lock:
ffff88801b8d8930 (&group->mark_mutex){+.+.}-{3:3}, at: fsnotify_group_lock include/linux/fsnotify_backend.h:270 [inline]
ffff88801b8d8930 (&group->mark_mutex){+.+.}-{3:3}, at: fsnotify_destroy_mark+0x38/0x3c0 fs/notify/mark.c:578
but task is already holding lock:
ffffffff8ea2fd60 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6841 [inline]
ffffffff8ea2fd60 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbb4/0x35a0 mm/vmscan.c:7223
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (fs_reclaim){+.+.}-{0:0}:
...
kmem_cache_alloc_noprof+0x3d/0x2a0 mm/slub.c:4044
inotify_new_watch fs/notify/inotify/inotify_user.c:599 [inline]
inotify_update_watch fs/notify/inotify/inotify_user.c:647 [inline]
__do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:786 [inline]
__se_sys_inotify_add_watch+0x72e/0x1070 fs/notify/inotify/inotify_user.c:729
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&group->mark_mutex){+.+.}-{3:3}:
...
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
fsnotify_group_lock include/linux/fsnotify_backend.h:270 [inline]
fsnotify_destroy_mark+0x38/0x3c0 fs/notify/mark.c:578
fsnotify_destroy_marks+0x14a/0x660 fs/notify/mark.c:934
fsnotify_inoderemove include/linux/fsnotify.h:264 [inline]
dentry_unlink_inode+0x2e0/0x430 fs/dcache.c:403
__dentry_kill+0x20d/0x630 fs/dcache.c:610
shrink_kill+0xa9/0x2c0 fs/dcache.c:1055
shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1082
prune_dcache_sb+0x10f/0x180 fs/dcache.c:1163
super_cache_scan+0x34f/0x4b0 fs/super.c:221
do_shrink_slab+0x701/0x1160 mm/shrinker.c:435
shrink_slab+0x1093/0x14d0 mm/shrinker.c:662
shrink_one+0x43b/0x850 mm/vmscan.c:4815
shrink_many mm/vmscan.c:4876 [inline]
lru_gen_shrink_node mm/vmscan.c:4954 [inline]
shrink_node+0x3799/0x3de0 mm/vmscan.c:5934
kswapd_shrink_node mm/vmscan.c:6762 [inline]
balance_pgdat mm/vmscan.c:6954 [inline]
kswapd+0x1bcd/0x35a0 mm/vmscan.c:7223
[Analysis]
The problem is that inotify_new_watch() is using GFP_KERNEL to allocate
new watches under group->mark_mutex, however if dentry reclaim races
with unlinking of an inode, it can end up dropping the last dentry reference
for an unlinked inode resulting in removal of fsnotify mark from reclaim
context which wants to acquire group->mark_mutex as well.
This scenario shows that all notification groups are in principle prone
to this kind of a deadlock (previously, we considered only fanotify and
dnotify to be problematic for other reasons) so make sure all
allocations under group->mark_mutex happen with GFP_NOFS.
Reported-and-tested-by: syzbot+c679f13773f295d2da53@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c679f13773f295d2da53
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240927143642.2369508-1-lizhi.xu@windriver.com
Benjamin Coddington <bcodding@redhat.com> says:
Last year both GFS2 and OCFS2 had some work done to make their locking more
robust when exported over NFS. Unfortunately, part of that work caused both
NLM (for NFS v3 exports) and kNFSD (for NFSv4.1+ exports) to no longer send
lock notifications to clients.
This in itself is not a huge problem because most NFS clients will still
poll the server in order to acquire a conflicted lock, but now that I've
noticed it I can't help but try to fix it because there are big advantages
for setups that might depend on timely lock notifications, and we've
supported that as a feature for a long time.
Its important for NLM and kNFSD that they do not block their kernel threads
inside filesystem's file_lock implementations because that can produce
deadlocks. We used to make sure of this by only trusting that
posix_lock_file() can correctly handle blocking lock calls asynchronously,
so the lock managers would only setup their file_lock requests for async
callbacks if the filesystem did not define its own lock() file operation.
However, when GFS2 and OCFS2 grew the capability to correctly
handle blocking lock requests asynchronously, they started signalling this
behavior with EXPORT_OP_ASYNC_LOCK, and the check for also trusting
posix_lock_file() was inadvertently dropped, so now most filesystems no
longer produce lock notifications when exported over NFS.
I tried to fix this by simply including the old check for lock(), but the
resulting include mess and layering violations was more than I could accept.
There's a much cleaner way presented here using an fop_flag, which while
potentially flag-greedy, greatly simplifies the problem and grooms the
way for future uses by both filesystems and lock managers alike.
* patches from https://lore.kernel.org/r/cover.1726083391.git.bcodding@redhat.com:
exportfs: Remove EXPORT_OP_ASYNC_LOCK
NLM/NFSD: Fix lock notifications for async-capable filesystems
gfs2/ocfs2: set FOP_ASYNC_LOCK
fs: Introduce FOP_ASYNC_LOCK
NFS: trace: show TIMEDOUT instead of 0x6e
nfsd: use system_unbound_wq for nfsd_file_gc_worker()
nfsd: count nfsd_file allocations
nfsd: fix refcount leak when file is unhashed after being found
nfsd: remove unneeded EEXIST error check in nfsd_do_file_acquire
nfsd: add list_head nf_gc to struct nfsd_file
Link: https://lore.kernel.org/r/cover.1726083391.git.bcodding@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Instead of checking just the exportfs flag, use the new
locks_can_async_lock() helper which allows NLM and NFSD to once again
support lock notifications for all filesystems which use posix_lock_file().
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Link: https://lore.kernel.org/r/865c40da44af67939e8eb560d17a26c9c50f23e0.1726083391.git.bcodding@redhat.com
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The LOCALIO auxiliary RPC protocol consists of a single "UUID_IS_LOCAL"
RPC method that allows the Linux NFS client to verify the local Linux
NFS server can see the nonce (single-use UUID) the client generated and
made available in nfs_common. The server expects this protocol to use
the same transport as NFS and NFSACL for its RPCs. This protocol
isn't part of an IETF standard, nor does it need to be considering it
is Linux-to-Linux auxiliary RPC protocol that amounts to an
implementation detail.
The UUID_IS_LOCAL method encodes the client generated uuid_t in terms of
the fixed UUID_SIZE (16 bytes). The fixed size opaque encode and decode
XDR methods are used instead of the less efficient variable sized
methods.
The RPC program number for the NFS_LOCALIO_PROGRAM is 400122 (as assigned
by IANA, see https://www.iana.org/assignments/rpc-program-numbers/ ):
Linux Kernel Organization 400122 nfslocalio
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
[neilb: factored out and simplified single localio protocol]
Co-developed-by: NeilBrown <neilb@suse.de>
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Add server support for bypassing NFS for localhost reads, writes, and
commits. This is only useful when both the client and server are
running on the same host.
If nfsd_open_local_fh() fails then the NFS client will both retry and
fallback to normal network-based read, write and commit operations if
localio is no longer supported.
Care is taken to ensure the same NFS security mechanisms are used
(authentication, etc) regardless of whether localio or regular NFS
access is used. The auth_domain established as part of the traditional
NFS client access to the NFS server is also used for localio. Store
auth_domain for localio in nfsd_uuid_t and transfer it to the client
if it is local to the server.
Relative to containers, localio gives the client access to the network
namespace the server has. This is required to allow the client to
access the server's per-namespace nfsd_net struct.
This commit also introduces the use of NFSD's percpu_ref to interlock
nfsd_destroy_serv and nfsd_open_local_fh, to ensure nn->nfsd_serv is
not destroyed while in use by nfsd_open_local_fh and other LOCALIO
client code.
CONFIG_NFS_LOCALIO enables NFS server support for LOCALIO.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Co-developed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Co-developed-by: NeilBrown <neilb@suse.de>
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
