The NFSv4 delegation spec allows the server to tell a client to limit how
much data it cache after the file is closed. In return, the server
guarantees enough free space to avoid ENOSPC situations, etc.
Prior to this patch, we assumed we could always cache aggressively after
close. Unfortunately, this causes problems with servers that set the
limit to 0 and therefore do not offer any ENOSPC guarantees.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Since we're tracking modifications to the page cache on a per-page
basis, it makes sense to express the limit to how much we may cache
in units of pages.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* bugfixes:
NFSv4: Return delegations synchronously in evict_inode
SUNRPC: Fix a regression when reconnecting
NFS: remount with security change should return EINVAL
nfs: do not export discarded symbols
NFSv4.1: don't export static symbol
Kinglong Mee reports that asynchronous delegations are being killed
by the call to rpc_shutdown_client() when unmounting. This can lead
to state leakage on the server until the client lease expires.
Reported-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Do so on the assumption that for most use cases, that list will turn into
a more or less LRU-ordered list, and so the list traversals in
nfs_client_return_marked_delegations() are likely to be shorter before
hitting a candidate to return.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
In nfs_client_return_marked_delegations() and nfs_delegation_reap_unclaimed()
we want to optimise the loop traversal by skipping delegations that are
already in the process of being returned.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This patch ensures that the superblock doesn't go ahead and disappear
underneath us while the state manager thread is returning delegations.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Ensure that nfs_inode_set_delegation() doesn't inadvertently detach a
delegation that is already in the process of being returned.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Merge cleanups requested by Linus.
* cleanups: (3 commits)
pnfs: Refactor the *_layout_mark_request_commit to use pnfs_layout_mark_request_commit
nfs: Can call nfs_clear_page_commit() instead
nfs: Provide and use helper functions for marking a page as unstable
Highlights incluse:
Features:
- Removing the forced serialisation of open()/close() calls in NFSv4.x (x>0)
makes for a significant performance improvement in metadata intensive
workloads.
- Full support for the pNFS "flexible files" layout type
- Further RPC/RDMA client improvements from Chuck
Bugfixes:
- Stable fix: NFSv4.1 backchannel calls blocking operations with !TASK_RUNNING
- Stable fix: pnfs_generic_pg_init_read/write can be called with lseg == NULL
- Stable fix: Fix an Oopsable condition when nsm_mon_unmon is called as part
of the namespace cleanup,
- Stable fix: Ensure we reference the inode for return-on-close in delegreturn
- Use SO_REUSEPORT to ensure that NFSv3 TCP connections can rebind to the
same source address/port combination during a disconnect/reconnect event.
This is a requirement imposed by most NFSv3 server duplicate reply cache
implementations.
Optimisations:
- Ask for no NFSv4.1 delegations on OPEN if using O_DIRECT
Other:
- Add Anna Schumaker as co-maintainer for the NFS client
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Merge tag 'nfs-for-3.20-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
"Highlights incluse:
Features:
- Removing the forced serialisation of open()/close() calls in
NFSv4.x (x>0) makes for a significant performance improvement in
metadata intensive workloads.
- Full support for the pNFS "flexible files" layout type
- Further RPC/RDMA client improvements from Chuck
Bugfixes:
- Stable fix: NFSv4.1 backchannel calls blocking operations with !TASK_RUNNING
- Stable fix: pnfs_generic_pg_init_read/write can be called with lseg == NULL
- Stable fix: Fix an Oopsable condition when nsm_mon_unmon is called
as part of the namespace cleanup,
- Stable fix: Ensure we reference the inode for return-on-close in
delegreturn
- Use SO_REUSEPORT to ensure that NFSv3 TCP connections can rebind to
the same source address/port combination during a disconnect/
reconnect event. This is a requirement imposed by most NFSv3
server duplicate reply cache implementations.
Optimisations:
- Ask for no NFSv4.1 delegations on OPEN if using O_DIRECT
Other:
- Add Anna Schumaker as co-maintainer for the NFS client"
* tag 'nfs-for-3.20-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (119 commits)
SUNRPC: Cleanup to remove xs_tcp_close()
pnfs: delete an unintended goto
pnfs/flexfiles: Do not dprintk after the free
SUNRPC: Fix stupid typo in xs_sock_set_reuseport
SUNRPC: Define xs_tcp_fin_timeout only if CONFIG_SUNRPC_DEBUG
SUNRPC: Handle connection reset more efficiently.
SUNRPC: Remove the redundant XPRT_CONNECTION_CLOSE flag
SUNRPC: Make xs_tcp_close() do a socket shutdown rather than a sock_release
SUNRPC: Ensure xs_tcp_shutdown() requests a full close of the connection
SUNRPC: Cleanup to remove remaining uses of XPRT_CONNECTION_ABORT
SUNRPC: Remove TCP socket linger code
SUNRPC: Remove TCP client connection reset hack
SUNRPC: TCP/UDP always close the old socket before reconnecting
SUNRPC: Add helpers to prevent socket create from racing
SUNRPC: Ensure xs_reset_transport() resets the close connection flags
SUNRPC: Do not clear the source port in xs_reset_transport
SUNRPC: Handle EADDRINUSE on connect
SUNRPC: Set SO_REUSEPORT socket option for TCP connections
NFSv4.1: Fix pnfs_put_lseg races
NFSv4.1: pnfs_send_layoutreturn should use GFP_NOFS
...
Ensure that we deal correctly with the case where the server sends us a
newer instance of the same delegation. If the stateids match, but the
sequence numbers differ, then treat the new delegation as if it were
an atomic upgrade.
Signed-off-by: Trond Myklebust <Trond.Myklebust@primarydata.com>
We can now add a dedicated spinlock without expanding struct inode.
Change to using that to protect the various i_flctx lists.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Any attempt to call nfs_remove_bad_delegation() while a delegation is being
returned is currently a no-op. This means that we can end up looping
forever in nfs_end_delegation_return() if something causes the delegation
to be revoked.
This patch adds a mechanism whereby the state recovery code can communicate
to the delegation return code that the delegation is no longer valid and
that it should not be used when reclaiming state.
It also changes the return value for nfs4_handle_delegation_recall_error()
to ensure that nfs_end_delegation_return() does not reattempt the lock
reclaim before state recovery is done.
http://lkml.kernel.org/r/CAN-5tyHwG=Cn2Q9KsHWadewjpTTy_K26ee+UnSvHvG4192p-Xw@mail.gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The clean-up in commit 36281caa83 ended up removing a NULL pointer check
that is needed in order to prevent an Oops in
nfs_async_inode_return_delegation().
Reported-by: "Yan, Zheng" <zheng.z.yan@intel.com>
Link: http://lkml.kernel.org/r/5313E9F6.2020405@intel.com
Fixes: 36281caa83 (NFSv4: Further clean-ups of delegation stateid validation)
Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Set up tracepoints to track when delegations are set, reclaimed,
returned by the client, or recalled by the server.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Having a global lock that protects all of this code is a clear
scalability problem. Instead of doing that, move most of the code to be
protected by the i_lock instead. The exceptions are the global lists
that the ->fl_link sits on, and the ->fl_block list.
->fl_link is what connects these structures to the
global lists, so we must ensure that we hold those locks when iterating
over or updating these lists.
Furthermore, sound deadlock detection requires that we hold the
blocked_list state steady while checking for loops. We also must ensure
that the search and update to the list are atomic.
For the checking and insertion side of the blocked_list, push the
acquisition of the global lock into __posix_lock_file and ensure that
checking and update of the blocked_list is done without dropping the
lock in between.
On the removal side, when waking up blocked lock waiters, take the
global lock before walking the blocked list and dequeue the waiters from
the global list prior to removal from the fl_block list.
With this, deadlock detection should be race free while we minimize
excessive file_lock_lock thrashing.
Finally, in order to avoid a lock inversion problem when handling
/proc/locks output we must ensure that manipulations of the fl_block
list are also protected by the file_lock_lock.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The second check was added in commit 65b62a29 but it will never be true.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the state manager thread is already running, we may end up
racing with it in nfs_client_return_marked_delegations. Better to
just allow the state manager thread to do the job.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, if the application that holds the file open isn't doing
I/O, we may end up returning the delegation. This means that we can
no longer cache the file as aggressively, and often also that we
multiply the state that both the server and the client needs to track.
This patch adds a check for open files to the routine that scans
for delegations that are unreferenced.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Add a mutex to the struct nfs4_state_owner to ensure that delegation
recall doesn't conflict with byte range lock removal.
Note that we nest the new mutex _outside_ the state manager reclaim
protection (nfsi->rwsem) in order to avoid deadlocks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the server reboots while we are converting a delegation into
OPEN/LOCK stateids as part of a delegation return, the current code
will simply exit with an error. This causes us to lose both
delegation state and locking state (i.e. locking atomicity).
Deal with this by exposing the delegation stateid during delegation
return, so that we can recover the delegation, and then resume
open/lock recovery.
Note that not having to hold the nfs_inode->rwsem across the
calls to nfs_delegation_claim_opens() also fixes a deadlock against
the NFSv4.1 reboot recovery code.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Delegations are a v4 feature, so push return_delegation out of the
generic client by creating a new rpc_op and renaming the old function to
be in the nfs v4 "namespace"
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Delegations are a v4 feature, so push them out of the generic code.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
I can use this function to return delegations and unset the pnfs layout
driver rather than continuing to do these things in the generic client.
With this change, we no longer need an nfs4_kill_super().
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Since even filemap_flush() needs to lock pages that are dirty, we
cannot risk calling it from the state manager context. Therefore,
we need to move the call to filemap_flush() to
nfs_async_inode_return_delegation().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The assumption is that if you are in a situation where you need to
return the delegation, then you should probably stop caching the
data anyway.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix a number of "warning: symbol 'foo' was not declared. Should it be
static?" conditions.
Fix 2 cases of "warning: Using plain integer as NULL pointer"
fs/nfs/delegation.c:263:31: warning: restricted fmode_t degrades to integer
- We want to allow upgrades to a WRITE delegation, but should otherwise
consider servers that hand out duplicate delegations to be borken.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When the NFSv4.0 server tells us that it can no-longer talk to us
on the callback channel, we should attempt a new SETCLIENTID in
order to re-transmit the callback channel information.
Note that as long as we do not change the boot verifier, this is
a safe procedure; the server is required to keep our state.
Also move the function nfs_handle_cb_pathdown to fs/nfs/nfs4state.c,
and change the name in order to mark it as being specific to NFSv4.0.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Handle DS READ and WRITE stateid errors by recovering the stateid on the MDS.
NFS4ERR_OLD_STATEID is ignored as the client always sends a
state sequenceid of zero for DS READ and WRITE stateids.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Change the name to reflect what we're really doing: testing two
stateids for whether or not they match according the the rules in
RFC3530 and RFC5661.
Move the code from callback_proc.c to nfs4proc.c
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
nfs41_validate_delegation_stateid is broken if we supply a stateid with
a non-zero sequence id. Instead of trying to match the sequence id,
the function assumes that we always want to error. While this is
true for a delegation callback, it is not true in general.
Also fix a typo in nfs4_callback_recall.
Reported-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we know that the delegation stateid is bad or revoked, we need to
remove that delegation as soon as possible, and then mark all the
stateids that relied on that delegation for recovery. We cannot use
the delegation as part of the recovery process.
Also note that NFSv4.1 uses a different error code (NFS4ERR_DELEG_REVOKED)
to indicate that the delegation was revoked.
Finally, ensure that setlk() and setattr() can both recover safely from
a revoked delegation.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
nfs_mark_return_delegation() is usually called without any locking, and
so it is not safe to dereference delegation->inode. Since the inode is
only used to discover the nfs_client anyway, it makes more sense to
have the callers pass a valid pointer to the nfs_server as a parameter.
Reported-by: Ian Kent <raven@themaw.net>
Cc: stable@kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The rcu callback nfs_free_delegation_callback() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(nfs_free_delegation_callback).
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
There is no reason to be freeing the delegation cred in the rcu callback,
and doing so is resulting in a lockdep complaint that rpc_credcache_lock
is being called from both softirq and non-softirq contexts.
Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
Delegations are per-inode, not per-nfs_client. When a server file
system is migrated, delegations on the client must be moved from the
source to the destination nfs_server. Make it easier to manage a
mount point's delegation list across a migration event by moving the
list to the nfs_server struct.
Clean up: I added documenting comments to public functions I changed
in this patch. For consistency I added comments to all the other
public functions in fs/nfs/delegation.c.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: Refactor code that takes clp->cl_lock and calls
nfs_detach_delegations_locked() into its own function.
While we're changing the call sites, get rid of the second parameter
and the logic in nfs_detach_delegations_locked() that uses it, since
callers always set that parameter of nfs_detach_delegations_locked()
to NULL.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
