The premise that "Once an svc thread is scheduled and executing an
RPC, no other processes will touch svc_rqst::rq_flags" is false.
svc_xprt_enqueue() examines the RQ_BUSY flag in scheduled nfsd
threads when determining which thread to wake up next.
Fixes: 9315564747cb ("NFSD: Use only RQ_DROPME to signal the need to drop a reply") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The premise that "Once an svc thread is scheduled and executing an
RPC, no other processes will touch svc_rqst::rq_flags" is false.
svc_xprt_enqueue() examines the RQ_BUSY flag in scheduled nfsd
threads when determining which thread to wake up next.
Found via KCSAN.
Fixes: 28df0988815f ("SUNRPC: Use RMW bitops in single-threaded hot paths") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Commit fb70bf124b05 ("NFSD: Instantiate a struct file when creating a
regular NFSv4 file") added the ability to cache an open fd over a
compound. There are a couple of problems with the way this currently
works:
It's racy, as a newly-created nfsd_file can end up with its PENDING bit
cleared while the nf is hashed, and the nf_file pointer is still zeroed
out. Other tasks can find it in this state and they expect to see a
valid nf_file, and can oops if nf_file is NULL.
Also, there is no guarantee that we'll end up creating a new nfsd_file
if one is already in the hash. If an extant entry is in the hash with a
valid nf_file, nfs4_get_vfs_file will clobber its nf_file pointer with
the value of op_file and the old nf_file will leak.
Fix both issues by making a new nfsd_file_acquirei_opened variant that
takes an optional file pointer. If one is present when this is called,
we'll take a new reference to it instead of trying to open the file. If
the nfsd_file already has a valid nf_file, we'll just ignore the
optional file and pass the nfsd_file back as-is.
Also rework the tracepoints a bit to allow for an "opened" variant and
don't try to avoid counting acquisitions in the case where we already
have a cached open file.
Fixes: fb70bf124b05 ("NFSD: Instantiate a struct file when creating a regular NFSv4 file") Cc: Trond Myklebust <trondmy@hammerspace.com> Reported-by: Stanislav Saner <ssaner@redhat.com> Reported-and-Tested-by: Ruben Vestergaard <rubenv@drcmr.dk> Reported-and-Tested-by: Torkil Svensgaard <torkil@drcmr.dk> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The filecache refcounting is a bit non-standard for something searchable
by RCU, in that we maintain a sentinel reference while it's hashed. This
in turn requires that we have to do things differently in the "put"
depending on whether its hashed, which we believe to have led to races.
There are other problems in here too. nfsd_file_close_inode_sync can end
up freeing an nfsd_file while there are still outstanding references to
it, and there are a number of subtle ToC/ToU races.
Rework the code so that the refcount is what drives the lifecycle. When
the refcount goes to zero, then unhash and rcu free the object. A task
searching for a nfsd_file is allowed to bump its refcount, but only if
it's not already 0. Ensure that we don't make any other changes to it
until a reference is held.
With this change, the LRU carries a reference. Take special care to deal
with it when removing an entry from the list, and ensure that we only
repurpose the nf_lru list_head when the refcount is 0 to ensure
exclusive access to it.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When built with Control Flow Integrity, function prototypes between
caller and function declaration must match. These mismatches are visible
at compile time with the new -Wcast-function-type-strict in Clang[1].
There were 97 warnings produced by NFS. For example:
fs/nfsd/nfs4xdr.c:2228:17: warning: cast from '__be32 (*)(struct nfsd4_compoundargs *, struct nfsd4_access *)' (aka 'unsigned int (*)(struct nfsd4_compoundargs *, struct nfsd4_access *)') to 'nfsd4_dec' (aka 'unsigned int (*)(struct nfsd4_compoundargs *, void *)') converts to incompatible function type [-Wcast-function-type-strict]
[OP_ACCESS] = (nfsd4_dec)nfsd4_decode_access,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The enc/dec callbacks were defined as passing "void *" as the second
argument, but were being implicitly cast to a new type. Replace the
argument with union nfsd4_op_u, and perform explicit member selection
in the function body. There are no resulting binary differences.
Changes were made mechanically using the following Coccinelle script,
with minor by-hand fixes for members that didn't already match their
existing argument name:
@find@
identifier func;
type T, opsT;
identifier ops, N;
@@
@convert@
identifier find.func;
type proto.T;
identifier proto.name;
position proto.p;
identifier get_member.member;
@@
func@p(...,
- T name
+ union nfsd4_op_u *u
) {
+ T name = &u->member;
...
}
@cast@
identifier find.func;
type T, opsT;
identifier ops, N;
@@
opsT ops[] = {
[N] =
- (T)
func,
};
Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Gustavo A. R. Silva <gustavoars@kernel.org> Cc: linux-nfs@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: NFSv2 has the only two usages of rpc_drop_reply in the
NFSD code base. Since NFSv2 is going away at some point, replace
these in order to simplify the "drop this reply?" check in
nfsd_dispatch().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The delegation reaper is called by nfsd memory shrinker's on
the 'count' callback. It scans the client list and sends the
courtesy CB_RECALL_ANY to the clients that hold delegations.
To avoid flooding the clients with CB_RECALL_ANY requests, the
delegation reaper sends only one CB_RECALL_ANY request to each
client per 5 seconds.
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
[ cel: moved definition of RCA4_TYPE_MASK_RDATA_DLG ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Steven Rostedt says:
> The include/trace/events/ directory should only hold files that
> are to create events, not headers that hold helper functions.
>
> Can you please move them out of include/trace/events/ as that
> directory is "special" in the creation of events.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Acked-by: Leon Romanovsky <leonro@nvidia.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Stable-dep-of: 638593be55c0 ("NFSD: add CB_RECALL_ANY tracepoints") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
We currently do a lock_to_openmode call based on the arguments from the
NLM_UNLOCK call, but that will always set the fl_type of the lock to
F_UNLCK, and the O_RDONLY descriptor is always chosen.
Fix it to use the file_lock from the block instead.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Shared locks are set on O_RDONLY descriptors and exclusive locks are set
on O_WRONLY ones. nlmsvc_unlock however calls vfs_lock_file twice, once
for each descriptor, but it doesn't reset fl_file. Ensure that it does.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
With the addition of POSIX ACLs to struct nfsd_attrs, we no longer
return an error if setting the ACL fails. Ensure we return the na_aclerr
error on SETATTR if there is one.
Fixes: c0cbe70742f4 ("NFSD: add posix ACLs to struct nfsd_attrs") Cc: Neil Brown <neilb@suse.de> Reported-by: Yongcheng Yang <yoyang@redhat.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Add a tracepoint to capture the number of filecache-triggered fsync
calls and which files needed it. Also, record when an fsync triggers
a write verifier reset.
We don't really care whether there are hashed entries when it comes to
scheduling the laundrette. They might all be non-gc entries, after all.
We only want to schedule it if there are entries on the LRU.
Switch to using list_lru_count, and move the check into
nfsd_file_gc_worker. The other callsite in nfsd_file_put doesn't need to
count entries, since it only schedules the laundrette after adding an
entry to the LRU.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
There are a number of places in the kernel that are accessing the
inode->i_flctx field without smp_load_acquire. This is required to
ensure that the caller doesn't see a partially-initialized structure.
Add a new accessor function for it to make this clear and convert all of
the relevant accesses in locks.c to use it. Also, convert
locks_free_lock_context to use the helper as well instead of just doing
a "bare" assignment.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jeff Layton <jlayton@kernel.org>
Stable-dep-of: 77c67530e1f9 ("nfsd: use locks_inode_context helper") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
In a coming patch, we're going to rework how the filecache refcounting
works. Move some code around in the function to reduce the churn in the
later patches, and rename some of the functions with (hopefully) clearer
names: nfsd_file_flush becomes nfsd_file_fsync, and
nfsd_file_unhash_and_dispose is renamed to nfsd_file_unhash_and_queue.
Also, the nfsd_file_put_final tracepoint is renamed to nfsd_file_free,
to better match the name of the function from which it's called.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
We're counting mapping->nrpages, but not all of those are necessarily
dirty. We don't really have a simple way to count just the dirty pages,
so just remove this stat since it's not accurate.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
fh_match() is costly, especially when filehandles are large (as is
the case for NFSv4). It needs to be used sparingly when searching
data structures. Unfortunately, with common workloads, I see
multiple thousands of objects stored in file_hashtbl[], which has
just 256 buckets, making its bucket hash chains quite lengthy.
Walking long hash chains with the state_lock held blocks other
activity that needs that lock. Sizable hash chains are a common
occurrance once the server has handed out some delegations, for
example -- IIUC, each delegated file is held open on the server by
an nfs4_file object.
To help mitigate the cost of searching with fh_match(), replace the
nfs4_file hash table with an rhashtable, which can dynamically
resize its bucket array to minimize hash chain length.
The result of this modification is an improvement in the latency of
NFSv4 operations, and the reduction of nfsd CPU utilization due to
eliminating the cost of multiple calls to fh_match() and reducing
the CPU cache misses incurred while walking long hash chains in the
nfs4_file hash table.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
find_file() is now the only caller of find_file_locked(), so just
fold these two together.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Remove the call to find_file_locked() in insert_nfs4_file(). Tracing
shows that over 99% of these calls return NULL. Thus it is not worth
the expense of the extra bucket list traversal. insert_file() already
deals correctly with the case where the item is already in the hash
bucket.
Since nfsd4_file_hash_insert() is now just a wrapper around
insert_file(), move the meat of insert_file() into
nfsd4_file_hash_insert() and get rid of it.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor to relocate hash deletion operation to a helper function
that is close to most other nfs4_file data structure operations.
The "noinline" annotation will become useful in a moment when the
hlist_del_rcu() is replaced with a more complex rhash remove
operation. It also guarantees that hash remove operations can be
traced with "-p function -l remove_nfs4_file_locked".
This also simplifies the organization of forward declarations: the
to-be-added rhashtable and its param structure will be defined
/after/ put_nfs4_file().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Name this function more consistently. I'm going to use nfsd4_file_
and nfsd4_file_hash_ for these helpers.
Change the @fh parameter to be const pointer for better type safety.
Finally, move the hash insertion operation to the caller. This is
typical for most other "init_object" type helpers, and it is where
most of the other nfs4_file hash table operations are located.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Enable callers to use const pointers for type safety.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Enable callers to use const pointers where they are able to.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Delegation revocation is an exceptional event that is not otherwise
visible externally (eg, no network traffic is emitted). Generate a
trace record when it occurs so that revocation can be observed or
other activity can be triggered. Example:
Trace infrastructure is provided for subsequent additional tracing
related to nfs4_stid activity.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Handing out a delegation stateid is recorded with the
nfsd_deleg_read tracepoint, but there isn't a matching tracepoint
for recording when the stateid is returned.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Remove the lame-duck dprintk()s around nfs4_preprocess_stateid_op()
call sites.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
NFSv4 operations manage the lifetime of nfsd_file items they use by
means of NFSv4 OPEN and CLOSE. Hence there's no need for them to be
garbage collected.
Introduce a mechanism to enable garbage collection for nfsd_file
items used only by NFSv2/3 callers.
Note that the change in nfsd_file_put() ensures that both CLOSE and
DELEGRETURN will actually close out and free an nfsd_file on last
reference of a non-garbage-collected file.
Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=394 Suggested-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
That commit attempted to make files available to other users as soon
as all NFSv4 clients were done with them, rather than waiting until
the filecache LRU had garbage collected them.
It gets the reference counting wrong, for one thing.
But it also misses that DELEGRETURN should release a file in the
same fashion. In fact, any nfsd_file_put() on an file held open
by an NFSv4 client needs potentially to release the file
immediately...
Clear the way for implementing that idea.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
In a moment I'm going to introduce separate nfsd_file types, one of
which is garbage-collected; the other, not. The garbage-collected
variety is to be used by NFSv2 and v3, and the non-garbage-collected
variety is to be used by NFSv4.
nfsd_commit() is invoked by both NFSv3 and NFSv4 consumers. We want
nfsd_commit() to find and use the correct variety of cached
nfsd_file object for the NFS version that is in use.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
expfs.c has a bunch of dprintk statements which are unusable due to:
#define dprintk(fmt, args...) do{}while(0)
Use pr_debug so that they can be enabled dynamically.
Also make some minor changes to the debug statements to fix some
incorrect types, and remove __func__ which can be handled by dynamic
debug separately.
Signed-off-by: David Disseldorp <ddiss@suse.de> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
rpc.nfsd stopped supporting NFSv2 a year ago. Take the next logical
step toward deprecating it and allow NFSv2 support to be compiled out.
Add a new CONFIG_NFSD_V2 option that can be turned off and rework the
CONFIG_NFSD_V?_ACL option dependencies. Add a description that
discourages enabling it.
Also, change the description of CONFIG_NFSD to state that the always-on
version is now 3 instead of 2.
Finally, add an #ifdef around "case 2:" in __write_versions. When NFSv2
is disabled at compile time, this should make the kernel ignore attempts
to disable it at runtime, but still error out when trying to enable it.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Tom Talpey <tom@talpey.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfserrno() is common to all nfs versions, but nfsproc.c is specifically
for NFSv2. Move it to vfs.c, and the prototype to vfs.h.
While we're in here, remove the #ifdef EDQUOT check in this function.
It's apparently a holdover from the initial merge of the nfsd code in
1997. No other place in the kernel checks that that symbol is defined
before using it, so I think we can dispense with it here.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The kernel currently errors out if you attempt to enable or disable a
version that it doesn't recognize. Change it to ignore attempts to
disable an unrecognized version. If we don't support it, then there is
no harm in doing so.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Tom Talpey <tom@talpey.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
For some reason, the NFSv2 GETACL result encoder was fully converted
to use the new nfs_stream_encode_acl(), but the NFSv3 equivalent was
not similarly converted.
Fixes: 20798dfe249a ("NFSD: Update the NFSv3 GETACL result encoder to use struct xdr_stream") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Variable host_err is assigned a value that is never read, it is being
re-assigned a value in every different execution path in the following
switch statement. The assignment is redundant and can be removed.
Cleans up clang-scan warning:
warning: Value stored to 'host_err' is never read [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Chuck had suggested reverting READ_PLUS so it returns a single DATA
segment covering the requested read range. This prepares the server for
a future "sparse read" function so support can easily be added without
needing to rip out the old READ_PLUS code at the same time.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd currently doesn't access i_flctx safely everywhere. This requires a
smp_load_acquire, as the pointer is set via cmpxchg (a release
operation).
Acked-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
lockd currently doesn't access i_flctx safely. This requires a
smp_load_acquire, as the pointer is set via cmpxchg (a release
operation).
Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_lookup_dentry returns an export reference in addition to the dentry
ref. Ensure that we put it too.
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2138866 Fixes: 876c553cb410 ("NFSD: verify the opened dentry after setting a delegation") Reported-by: Yongcheng Yang <yoyang@redhat.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When we fail to insert into the hashtable with a non-retryable error,
we'll free the object and then goto out_status. If the tracepoint is
enabled, it'll end up accessing the freed object when it tries to
grab the fields out of it.
Set nf to NULL after freeing it to avoid the issue.
Fixes: 243a5263014a ("nfsd: rework hashtable handling in nfsd_do_file_acquire") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If the namespace doesn't match the one in "net", then we'll continue,
but that doesn't cause another rhashtable_walk_next call, so it will
loop infinitely.
Fixes: ce502f81ba88 ("NFSD: Convert the filecache to use rhashtable") Reported-by: Petr Vorel <pvorel@suse.cz> Link: https://lore.kernel.org/ltp/Y1%2FP8gDAcWC%2F+VR3@pevik/ Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
syzbot is reporting UAF read at register_shrinker_prepared() [1], for
commit 7746b32f467b3813 ("NFSD: add shrinker to reap courtesy clients on
low memory condition") missed that nfsd4_leases_net_shutdown() from
nfsd_exit_net() is called only when nfsd_init_net() succeeded.
If nfsd_init_net() fails due to nfsd_reply_cache_init() failure,
register_shrinker() from nfsd4_init_leases_net() has to be undone
before nfsd_init_net() returns.
Link: https://syzkaller.appspot.com/bug?extid=ff796f04613b4c84ad89 Reported-by: syzbot <syzbot+ff796f04613b4c84ad89@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Fixes: 7746b32f467b3813 ("NFSD: add shrinker to reap courtesy clients on low memory condition") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_file is RCU-freed, so we need to hold the rcu_read_lock long enough
to get a reference after finding it in the hash. Take the
rcu_read_lock() and call rhashtable_lookup directly.
Switch to using rhashtable_lookup_insert_key as well, and use the usual
retry mechanism if we hit an -EEXIST. Rename the "retry" bool to
open_retry, and eliminiate the insert_err goto target.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_file_unhash_and_dispose() is called for two reasons:
We're either shutting down and purging the filecache, or we've gotten a
notification about a file delete, so we want to go ahead and unhash it
so that it'll get cleaned up when we close.
We're either walking the hashtable or doing a lookup in it and we
don't take a reference in either case. What we want to do in both cases
is to try and unhash the object and put it on the dispose list if that
was successful. If it's no longer hashed, then we don't want to touch
it, with the assumption being that something else is already cleaning
up the sentinel reference.
Instead of trying to selectively decrement the refcount in this
function, just unhash it, and if that was successful, move it to the
dispose list. Then, the disposal routine will just clean that up as
usual.
Also, just make this a void function, drop the WARN_ON_ONCE, and the
comments about deadlocking since the nature of the purported deadlock
is no longer clear.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
All uses of fanotify_event_has_path() have
been removed since commit 9c61f3b560f5 ("fanotify: break up
fanotify_alloc_event()"), now it is useless, so remove it.
fsnotify_alloc_event_holder() and fsnotify_destroy_event_holder()
has been removed since commit 7053aee26a35 ("fsnotify: do not share
events between notification groups"), so remove it.
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Matthew Bobrowski <repnop@google.com> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
We've had some reports of problems in the refcounting for delegation
stateids that we've yet to track down. Add some extra checks to ensure
that we've removed the object from various lists before freeing it.
queue_work can return false and not queue anything, if the work is
already queued. If that happens in the case of a CB_RECALL, we'll have
taken an extra reference to the stid that will never be put. Ensure we
throw a warning in that case.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
In the case of a revoked delegation, we still fill out the pointer even
when returning an error, which is bad form. Only overwrite the pointer
on success.
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Since before the git era, NFSD has conserved the number of pages
held by each nfsd thread by combining the RPC receive and send
buffers into a single array of pages. This works because there are
no cases where an operation needs a large RPC Call message and a
large RPC Reply at the same time.
Once an RPC Call has been received, svc_process() updates
svc_rqst::rq_res to describe the part of rq_pages that can be
used for constructing the Reply. This means that the send buffer
(rq_res) shrinks when the received RPC record containing the RPC
Call is large.
Add an NFSv4 helper that computes the size of the send buffer. It
replaces svc_max_payload() in spots where svc_max_payload() returns
a value that might be larger than the remaining send buffer space.
Callers who need to know the transport's actual maximum payload size
will continue to use svc_max_payload().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Code maintenance: The name of the copy_stateid_t::sc_count field
collides with the sc_count field in struct nfs4_stid, making the
latter difficult to grep for when auditing stateid reference
counting.
No behavior change expected.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
These helpers are always invoked indirectly, so the compiler can't
inline these anyway. While we're updating the synopses of these
helpers, defensively convert their parameters to const pointers.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
In today's Linux NFS server implementation, the NFS dispatcher
initializes each XDR result stream, and the NFSv4 .pc_func and
.pc_encode methods all use xdr_stream-based encoding. This keeps
rq_res.len automatically updated. There is no longer a need for
the WARN_ON_ONCE() check in nfs4svc_encode_compoundres().
Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Replace the check for buffer over/underflow with a helper that is
commonly used for this purpose. The helper also sets xdr->nwords
correctly after successfully linearizing the symlink argument into
the stream's scratch buffer.
Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The dust has settled a bit and it's become obvious what code is
totally common between nfsd_init_dirlist_pages() and
nfsd3_init_dirlist_pages(). Move that common code to SUNRPC.
The new helper brackets the existing xdr_init_decode_pages() API.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Have SunRPC clear everything except for the iops array. Then have
each NFSv4 XDR decoder clear it's own argument before decoding.
Now individual operations may have a large argument struct while not
penalizing the vast majority of operations with a small struct.
And, clearing the argument structure occurs as the argument fields
are initialized, enabling the CPU to do write combining on that
memory. In some cases, clearing is not even necessary because all
of the fields in the argument structure are initialized by the
decoder.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently, SUNRPC clears the whole of .pc_argsize before processing
each incoming RPC transaction. Add an extra parameter to struct
svc_procedure to enable upper layers to reduce the amount of each
operation's argument structure that is zeroed by SUNRPC.
The size of struct nfsd4_compoundargs, in particular, is a lot to
clear on each incoming RPC Call. A subsequent patch will cut this
down to something closer to what NFSv2 and NFSv3 uses.
This patch should cause no behavior changes.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_unlink() can kick off a CB_RECALL (via
vfs_unlink() -> leases_conflict()) if a delegation is present.
Before returning NFS4ERR_DELAY, give the client holding that
delegation a chance to return it and then retry the nfsd_unlink()
again, once.
Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=354 Tested-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_rename() can kick off a CB_RECALL (via
vfs_rename() -> leases_conflict()) if a delegation is present.
Before returning NFS4ERR_DELAY, give the client holding that
delegation a chance to return it and then retry the nfsd_rename()
again, once.
This version of the patch handles renaming an existing file,
but does not deal with renaming onto an existing file. That
case will still always trigger an NFS4ERR_DELAY.
Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=354 Tested-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_setattr() can kick off a CB_RECALL (via
notify_change() -> break_lease()) if a delegation is present. Before
returning NFS4ERR_DELAY, give the client holding that delegation a
chance to return it and then retry the nfsd_setattr() again, once.
Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=354 Tested-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Suggested-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Wireshark has always been lousy about dissecting NFSv4 callbacks,
especially NFSv4.0 backchannel requests. Add tracepoints so we
can surgically capture these events in the trace log.
Tracepoints are time-stamped and ordered so that we can now observe
the timing relationship between a CB_RECALL Reply and the client's
DELEGRETURN Call. Example:
The Linux NFSv4 client implementation does not use COMPOUND tags,
but the Solaris and MacOS implementations do, and so does pynfs.
Record these eye-catchers in the server's trace buffer to annotate
client requests while troubleshooting.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Record permission errors in the trace log. Note that the new trace
event is conditional, so it will only record non-zero return values
from nfsd_permission().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
We only need the inode number for this, not a full rack of attributes.
Rename this function make it take a pointer to a u64 instead of
struct kstat, and change it to just request STATX_INO.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
[ cel: renamed get_mounted_on_ino() ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When attempting an NFSv4 mount, a Solaris NFSv4 client builds a
single large COMPOUND that chains a series of LOOKUPs to get to the
pseudo filesystem root directory that is to be mounted. The Linux
NFS server's current maximum of 16 operations per NFSv4 COMPOUND is
not large enough to ensure that this works for paths that are more
than a few components deep.
Since NFSD_MAX_OPS_PER_COMPOUND is mostly a sanity check, and most
NFSv4 COMPOUNDS are between 3 and 6 operations (thus they do not
trigger any re-allocation of the operation array on the server),
increasing this maximum should result in little to no impact.
The ops array can get large now, so allocate it via vmalloc() to
help ensure memory fragmentation won't cause an allocation failure.
If the passed in filehandle for the source file in the COPY operation
is not a regular file, the server MUST return NFS4ERR_WRONG_TYPE.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
[ cel: adjusted to apply to v5.15.y ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.
Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.
pipe_buffer might refer to a compound page (and contain more than a PAGE_SIZE
worth of data). Theoretically it had been possible since way back, but
nfsd_splice_actor() hadn't run into that until copy_page_to_iter() change.
Fortunately, the only thing that changes for compound pages is that we
need to stuff each relevant subpage in and convert the offset into offset
in the first subpage.
Acked-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Benjamin Coddington <bcodding@redhat.com> Fixes: f0f6b614f83d "copy_page_to_iter(): don't split high-order page in case of ITER_PIPE" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
A recent patch moved ACL setting into nfsd_setattr().
Unfortunately it didn't work as nfsd_setattr() aborts early if
iap->ia_valid is 0.
Remove this test, and instead avoid calling notify_change() when
ia_valid is 0.
This means that nfsd_setattr() will now *always* lock the inode.
Previously it didn't if only a ATTR_MODE change was requested on a
symlink (see Commit 15b7a1b86d66 ("[PATCH] knfsd: fix setattr-on-symlink
error return")). I don't think this change really matters.
Fixes: c0cbe70742f4 ("NFSD: add posix ACLs to struct nfsd_attrs") Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
As all inode locking is now fully balanced, fh_put() does not need to
call fh_unlock().
fh_lock() and fh_unlock() are no longer used, so discard them.
These are the only real users of ->fh_locked, so discard that too.
Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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