Add a FAQ section to give answers to questions that have been raised
during review of the localio feature.
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>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
This document gives an overview of the LOCALIO auxiliary RPC protocol
added to the Linux NFS client and server to allow them to reliably
handshake to determine if they are on the same host.
Once an NFS client and server handshake as "local", the client will
bypass the network RPC protocol for read, write and commit operations.
Due to this XDR and RPC bypass, these operations will operate faster.
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>
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 for subsequent lookup and verification
by the NFS server. If matched, the NFS server populates members in the
nfs_uuid_t struct. The NFS client then transfers these nfs_uuid_t
struct member pointers to the nfs_client struct and cleans up the
nfs_uuid_t struct. See: fs/nfs/localio.c:nfs_local_probe()
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.
Localio is only supported when UNIX-style authentication (AUTH_UNIX, aka
AUTH_SYS) is used (enforced by fs/nfs/localio.c:nfs_local_probe()).
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.
Having a nonce (single-use uuid) is better than using the same uuid
for the life of the server, and sending it proactively by client
rather than reactively by the server is also safer.
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>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
For localio access, don't call filesystem read() and write() routines
directly. This solves two problems:
1) localio writes need to use a normal (non-memreclaim) unbound
workqueue. This avoids imposing new requirements on how underlying
filesystems process frontend IO, which would cause a large amount
of work to update all filesystems. Without this change, when XFS
starts getting low on space, XFS flushes work on a non-memreclaim
work queue, which causes a priority inversion problem:
00573 workqueue: WQ_MEM_RECLAIM writeback:wb_workfn is flushing !WQ_MEM_RECLAIM xfs-sync/vdc:xfs_flush_inodes_worker
00573 WARNING: CPU: 6 PID: 8525 at kernel/workqueue.c:3706 check_flush_dependency+0x2a4/0x328
00573 Modules linked in:
00573 CPU: 6 PID: 8525 Comm: kworker/u71:5 Not tainted 6.10.0-rc3-ktest-00032-g2b0a133403ab #18502
00573 Hardware name: linux,dummy-virt (DT)
00573 Workqueue: writeback wb_workfn (flush-0:33)
00573 pstate: 400010c5 (nZcv daIF -PAN -UAO -TCO -DIT +SSBS BTYPE=--)
00573 pc : check_flush_dependency+0x2a4/0x328
00573 lr : check_flush_dependency+0x2a4/0x328
00573 sp : ffff0000c5f06bb0
00573 x29: ffff0000c5f06bb0 x28: ffff0000c998a908 x27: 1fffe00019331521
00573 x26: ffff0000d0620900 x25: ffff0000c5f06ca0 x24: ffff8000828848c0
00573 x23: 1fffe00018be0d8e x22: ffff0000c1210000 x21: ffff0000c75fde00
00573 x20: ffff800080bfd258 x19: ffff0000cad63400 x18: ffff0000cd3a4810
00573 x17: 0000000000000000 x16: 0000000000000000 x15: ffff800080508d98
00573 x14: 0000000000000000 x13: 204d49414c434552 x12: 1fffe0001b6eeab2
00573 x11: ffff60001b6eeab2 x10: dfff800000000000 x9 : ffff60001b6eeab3
00573 x8 : 0000000000000001 x7 : 00009fffe491154e x6 : ffff0000db775593
00573 x5 : ffff0000db775590 x4 : ffff0000db775590 x3 : 0000000000000000
00573 x2 : 0000000000000027 x1 : ffff600018be0d62 x0 : dfff800000000000
00573 Call trace:
00573 check_flush_dependency+0x2a4/0x328
00573 __flush_work+0x184/0x5c8
00573 flush_work+0x18/0x28
00573 xfs_flush_inodes+0x68/0x88
00573 xfs_file_buffered_write+0x128/0x6f0
00573 xfs_file_write_iter+0x358/0x448
00573 nfs_local_doio+0x854/0x1568
00573 nfs_initiate_pgio+0x214/0x418
00573 nfs_generic_pg_pgios+0x304/0x480
00573 nfs_pageio_doio+0xe8/0x240
00573 nfs_pageio_complete+0x160/0x480
00573 nfs_writepages+0x300/0x4f0
00573 do_writepages+0x12c/0x4a0
00573 __writeback_single_inode+0xd4/0xa68
00573 writeback_sb_inodes+0x470/0xcb0
00573 __writeback_inodes_wb+0xb0/0x1d0
00573 wb_writeback+0x594/0x808
00573 wb_workfn+0x5e8/0x9e0
00573 process_scheduled_works+0x53c/0xd90
00573 worker_thread+0x370/0x8c8
00573 kthread+0x258/0x2e8
00573 ret_from_fork+0x10/0x20
2) Some filesystem writeback routines can end up taking up a lot of
stack space (particularly XFS). Instead of risking running over
due to the extra overhead from the NFS stack, we should just call
these routines from a workqueue job. Since we need to do this to
address 1) above we're able to avoid possibly blowing the stack
"for free".
Use of dedicated workqueues improves performance over using the
system_unbound_wq.
Also, the creds used to open the file are used to override_creds() in
both nfs_local_call_read() and nfs_local_call_write() -- otherwise the
workqueue could have elevated capabilities (which the caller may not).
Lastly, care is taken to set PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO in
nfs_do_local_write() to avoid writeback deadlocks.
The PF_LOCAL_THROTTLE flag prevents deadlocks in balance_dirty_pages()
by causing writes to only be throttled against other writes to the
same bdi (it keeps the throttling local). Normally all writes to
bdi(s) are throttled equally (after throughput factors are allowed
for).
The PF_MEMALLOC_NOIO flag prevents the lower filesystem IO from
causing memory reclaim to re-enter filesystems or IO devices and so
prevents deadlocks from occuring where IO that cleans pages is
waiting on IO to complete.
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> # eliminated wait_for_completion
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
If the DS is local to this client use localio to write the data.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
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>
Try a local open of the file being written to, and if it succeeds,
then use localio to issue IO.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
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>
Add client support for bypassing NFS for localhost reads, writes, and
commits. This is only useful when the client and the server are
running on the same host.
nfs_local_probe() is stubbed out, later commits will enable client and
server handshake via a Linux-only LOCALIO auxiliary RPC protocol.
This has dynamic binding with the nfsd module (via nfs_localio module
which is part of nfs_common). LOCALIO will only work if nfsd is
already loaded.
The "localio_enabled" nfs kernel module parameter can be used to
disable and enable the ability to use LOCALIO support.
CONFIG_NFS_LOCALIO enables NFS client support for LOCALIO.
Lastly, LOCALIO uses an nfsd_file to initiate all IO. To make proper
use of nfsd_file (and nfsd's filecache) its lifetime (duration before
nfsd_file_put is called) must extend until after commit, read and
write operations. So rather than immediately drop the nfsd_file
reference in nfs_local_open_fh(), that doesn't happen until
nfs_local_pgio_release() for read/write and not until
nfs_local_release_commit_data() for commit. The same applies to the
reference held on nfsd's nn->nfsd_serv. Both objects' lifetimes and
associated references are managed through calls to
nfs_to->nfsd_file_put_local().
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>
Signed-off-by: NeilBrown <neilb@suse.de> # nfs_open_local_fh
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
The nfsd_file will be passed, in future commits, by callers
that enable LOCALIO support (for both regular NFS and pNFS IO).
[Derived from patch authored by Weston Andros Adamson, but switched
from passing struct file to struct nfsd_file]
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>
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>
The next commit will introduce nfsd_open_local_fh() which returns an
nfsd_file structure. This commit exposes LOCALIO's required NFSD
symbols to the NFS client:
- Make nfsd_open_local_fh() symbol and other required NFSD symbols
available to NFS in a global 'nfs_to' nfsd_localio_operations
struct (global access suggested by Trond, nfsd_localio_operations
suggested by NeilBrown). The next commit will also introduce
nfsd_localio_ops_init() that init_nfsd() will call to initialize
'nfs_to'.
- Introduce nfsd_file_file() that provides access to nfsd_file's
backing file. Keeps nfsd_file structure opaque to NFS client (as
suggested by Jeff Layton).
- Introduce nfsd_file_put_local() that will put the reference to the
nfsd_file's associated nn->nfsd_serv and then put the reference to
the nfsd_file (as suggested by NeilBrown).
Suggested-by: Trond Myklebust <trond.myklebust@hammerspace.com> # nfs_to
Suggested-by: NeilBrown <neilb@suse.de> # nfsd_localio_operations
Suggested-by: Jeff Layton <jlayton@kernel.org> # nfsd_file_file
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>
fs/nfs_common/nfslocalio.c provides interfaces that enable an NFS
client to generate a nonce (single-use UUID) and associated nfs_uuid_t
struct, register it with nfs_common for subsequent lookup and
verification by the NFS server and if matched the NFS server populates
members in the nfs_uuid_t struct.
nfs_common's nfs_uuids list is the basis for localio enablement, as
such it has members that point to nfsd memory for direct use by the
client (e.g. 'net' is the server's network namespace, through it the
client can access nn->nfsd_serv).
This commit also provides the base nfs_uuid_t interfaces to allow
proper net namespace refcounting for the LOCALIO use case.
CONFIG_NFS_LOCALIO controls the nfs_common, NFS server and NFS client
enablement for LOCALIO. If both NFS_FS=m and NFSD=m then
NFS_COMMON_LOCALIO_SUPPORT=m and nfs_localio.ko is built (and provides
nfs_common's LOCALIO support).
# lsmod | grep nfs_localio
nfs_localio 12288 2 nfsd,nfs
sunrpc 745472 35 nfs_localio,nfsd,auth_rpcgss,lockd,nfsv3,nfs
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>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
A service created with svc_create_pooled() can be given a linked list of
programs and all of these will be served.
Using a linked list makes it cumbersome when there are several programs
that can be optionally selected with CONFIG settings.
After this patch is applied, API consumers must use only
svc_create_pooled() when creating an RPC service that listens for more
than one RPC program.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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 new funtion svcauth_map_clnt_to_svc_cred_local which maps a
generic cred to a svc_cred suitable for use in nfsd.
This is needed by the localio code to map nfs client creds to nfs
server credentials.
Following from net/sunrpc/auth_unix.c:unx_marshal() it is clear that
->fsuid and ->fsgid must be used (rather than ->uid and ->gid). In
addition, these uid and gid must be translated with from_kuid_munged()
so local client uses correct uid and gid when acting as local server.
Jeff Layton noted:
This is where the magic happens. Since we're working in
kuid_t/kgid_t, we don't need to worry about further idmapping.
Suggested-by: NeilBrown <neilb@suse.de> # to approximate unx_marshal()
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>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Remove BUG_ON if p_arglen=0 to allow RPC with void arg.
Remove BUG_ON if p_replen=0 to allow RPC with void return.
The former was needed for the first revision of the LOCALIO protocol
which had an RPC that took a void arg:
/* raw RFC 9562 UUID */
typedef u8 uuid_t<UUID_SIZE>;
program NFS_LOCALIO_PROGRAM {
version LOCALIO_V1 {
void
NULL(void) = 0;
uuid_t
GETUUID(void) = 1;
} = 1;
} = 400122;
The latter is needed for the final revision of the LOCALIO protocol
which has a UUID_IS_LOCAL RPC which returns a void:
/* raw RFC 9562 UUID */
typedef u8 uuid_t<UUID_SIZE>;
program NFS_LOCALIO_PROGRAM {
version LOCALIO_V1 {
void
NULL(void) = 0;
void
UUID_IS_LOCAL(uuid_t) = 1;
} = 1;
} = 400122;
There is really no value in triggering a BUG_ON in response to either
of these previously unsupported conditions.
NeilBrown would like the entire 'if (proc->p_proc != 0)' branch
removed (not just the one BUG_ON that must be removed for LOCALIO's
immediate needs of returning void).
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>
Introduce nfsd_serv_try_get and nfsd_serv_put and update the nfsd code
to prevent nfsd_destroy_serv from destroying nn->nfsd_serv until any
caller of nfsd_serv_try_get releases their reference using nfsd_serv_put.
A percpu_ref is used to implement the interlock between
nfsd_destroy_serv and any caller of nfsd_serv_try_get.
This interlock is needed to properly wait for the completion of client
initiated localio calls to nfsd (that are _not_ in the context of nfsd).
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
nfsd_file_acquire_local() can be used to look up a file by filehandle
without having a struct svc_rqst. This can be used by NFS LOCALIO to
allow the NFS client to bypass the NFS protocol to directly access a
file provided by the NFS server which is running in the same kernel.
In nfsd_file_do_acquire() care is taken to always use fh_verify() if
rqstp is not NULL (as is the case for non-LOCALIO callers). Otherwise
the non-LOCALIO callers will not supply the correct and required
arguments to __fh_verify (e.g. gssclient isn't passed).
Introduce fh_verify_local() wrapper around __fh_verify to make it
clear that LOCALIO is intended caller.
Also, use GC for nfsd_file returned by nfsd_file_acquire_local. GC
offers performance improvements if/when a file is reopened before
launderette cleans it from the filecache's LRU.
Suggested-by: Jeff Layton <jlayton@kernel.org> # use filecache's GC
Signed-off-by: NeilBrown <neilb@suse.de>
Co-developed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
__fh_verify() offers an interface like fh_verify() but doesn't require
a struct svc_rqst *, instead it also takes the specific parts as
explicit required arguments. So it is safe to call __fh_verify() with
a NULL rqstp, but the net, cred, and client args must not be NULL.
__fh_verify() does not use SVC_NET(), nor does the functions it calls.
Rather than using rqstp->rq_client pass the client and gssclient
explicitly to __fh_verify and then to nfsd_set_fh_dentry().
Lastly, it should be noted that the previous commit prepared for 4
associated tracepoints to only be used if rqstp is not NULL (this is a
stop-gap that should be properly fixed so localio also benefits from
the utility these tracepoints provide when debugging fh_verify
issues).
Signed-off-by: NeilBrown <neilb@suse.de>
Co-developed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
LOCALIO will be able to call fh_verify() with a NULL rqstp. In this
case, the existing trace points need to be skipped because they
want to dereference the address fields in the passed-in rqstp.
Temporarily make these trace points conditional to avoid a seg
fault in this case. Putting the "rqstp != NULL" check in the trace
points themselves makes the check more efficient.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Currently, fh_verify() makes some daring assumptions about which
version of file handle the caller wants, based on the things it can
find in the passed-in rqstp. The about-to-be-introduced LOCALIO use
case sometimes has no svc_rqst context, so this logic won't work in
that case.
Instead, examine the passed-in file handle. It's .max_size field
should carry information to allow nfsd_set_fh_dentry() to initialize
the file handle appropriately.
The file handle used by lockd and the one created by write_filehandle
never need any of the version-specific fields (which affect things
like write and getattr requests and pre/post attributes).
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
There are several places where __fh_verify unconditionally dereferences
rqstp to check that the connection is suitably secure. They look at
rqstp->rq_xprt which is not meaningful in the target use case of
"localio" NFS in which the client talks directly to the local server.
Prepare these to always succeed when rqstp is NULL.
Signed-off-by: NeilBrown <neilb@suse.de>
Co-developed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
LOCALIO-initiated open operations are not running in an nfsd thread
and thus do not have an associated svc_rqst context.
Signed-off-by: NeilBrown <neilb@suse.de>
Co-developed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Eliminates duplicate functions in various files to allow for
additional callers.
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>
Common nfs4_stat_to_errno() is used by fs/nfs/nfs4xdr.c and will be
used by fs/nfs/localio.c
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Common nfs_stat_to_errno() is used by both fs/nfs/nfs2xdr.c and
fs/nfs/nfs3xdr.c
Will also be used by fs/nfsd/localio.c
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
There are some applications that write to predefined non-overlapping
file offsets from multiple clients and therefore don't need to rely on
file locking. However, if these applications want non-aligned offsets
and sizes they need to either use locks or risk data corruption, as the
NFS client defaults to extending writes to whole pages.
This commit adds a new mount option `noalignwrite`, which allows to turn
that off and avoid the need of locking, as long as these applications
don't overlap on offsets.
Signed-off-by: Dan Aloni <dan.aloni@vastdata.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
The comment for nfs_get_root() needs to be updated as it would also be
used by NFS4 as follows:
@x[
nfs_get_root+1
nfs_get_tree_common+1819
nfs_get_tree+2594
vfs_get_tree+73
fc_mount+23
do_nfs4_mount+498
nfs4_try_get_tree+134
nfs_get_tree+2562
vfs_get_tree+73
path_mount+2776
do_mount+226
__se_sys_mount+343
__x64_sys_mount+106
do_syscall_64+69
entry_SYSCALL_64_after_hwframe+97
, mount.nfs4]: 1
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
According to draft-ietf-nfsv4-delstid-07:
If a server informs the client via the fattr4_open_arguments
attribute that it supports
OPEN_ARGS_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS and it returns a valid
delegation stateid for an OPEN operation which sets the
OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS flag, then it MUST query the
client via a CB_GETATTR for the fattr4_time_deleg_access (see
Section 5.2) attribute and fattr4_time_deleg_modify attribute (see
Section 5.2).
Thus, we should look that the server supports proxying of times via
OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS.
We want to be extra pedantic and continue to check that FATTR4_TIME_DELEG_ACCESS
and FATTR4_TIME_DELEG_MODIFY are set. The server needs to expose both for the
client to correctly detect "Proxying of Times" support.
Signed-off-by: Roi Azarzar <roi.azarzar@vastdata.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Fixes: dcb3c20f74 ("NFSv4: Add a capability for delegated attributes")
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
If the server is down when the client is trying to mount, so that the
calls to exchange_id or create_session fail, then we should allow the
mount system call to fail rather than hang and block other mount/umount
calls.
Reported-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
This patch is inspired by a code review of fs codes which aims at
folio's extra refcnt that could introduce unwanted behavious when
judging refcnt, such as[1].That is, the folio passed to
mapping_evict_folio carries the refcnts from find_lock_entries,
page_cache, corresponding to PTEs and folio's private if has. However,
current code doesn't take the refcnt for folio's private which could
have mapping_evict_folio miss the one to only PTE and lead to
call filemap_release_folio wrongly.
[1]
long mapping_evict_folio(struct address_space *mapping, struct folio *folio)
{
...
//current code will misjudge here if there is one pte on the folio which
is be deemed as the one as folio's private
if (folio_ref_count(folio) >
folio_nr_pages(folio) + folio_has_private(folio) + 1)
return 0;
if (!filemap_release_folio(folio, 0))
return 0;
return remove_mapping(mapping, folio);
}
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
The nfs_read_prepare() have been removed since
commit a4cdda5911 ("NFS: Create a common pgio_rpc_prepare function"),
and now it is useless, so remove it.
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
list_head can be initialized automatically with LIST_HEAD()
instead of calling INIT_LIST_HEAD(). Here we can simplify
the code.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
destroy_wait doesn't store all RPC clients. There was a list named
"all_clients" above it, which got moved to struct sunrpc_net in 2012,
but the comment was never removed.
Fixes: 70abc49b4f ("SUNRPC: make SUNPRC clients list per network namespace context")
Signed-off-by: Siddh Raman Pant <siddh.raman.pant@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
The RPC_TASK_* constants are defined as macros, which means that most
kernel builds will not contain their definitions in the debuginfo.
However, it's quite useful for debuggers to be able to view the task
state constant and interpret it correctly. Conversion to an enum will
ensure the constants are present in debuginfo and can be interpreted by
debuggers without needing to hard-code them and track their changes.
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Increase size of the servername array to avoid truncated output warning.
net/sunrpc/clnt.c:582:75: error：‘%s’ directive output may be truncated
writing up to 107 bytes into a region of size 48
[-Werror=format-truncation=]
582 | snprintf(servername, sizeof(servername), "%s",
| ^~
net/sunrpc/clnt.c:582:33: note:‘snprintf’ output
between 1 and 108 bytes into a destination of size 48
582 | snprintf(servername, sizeof(servername), "%s",
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
583 | sun->sun_path);
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Suggested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Since kfree() already checks if its argument is NULL, an additional
check before calling kfree() is unnecessary and can be removed.
Remove it and thus also the following Coccinelle/coccicheck warning
reported by ifnullfree.cocci:
WARNING: NULL check before some freeing functions is not needed
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Add the __counted_by compiler attribute to the flexible array member
array to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.
Increment size before adding a new struct to the array.
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
I have evidence of an Linux NFS client getting NFS4ERR_BAD_SEQID to a
v4.0 LOCK request to a Linux server (which had fixed the problem with
RELEASE_LOCKOWNER bug fixed).
The LOCK request presented a "new" lock owner so there are two seq ids
in the request: that for the open file, and that for the new lock.
Given the context I am confident that the new lock owner was reported to
have the wrong seqid. As lock owner identifiers are reused, the server
must still have a lock owner active which the client thinks is no longer
active.
I wasn't able to determine a root-cause but the simplest fix seems to be
to ensure lock owners are always unique much as open owners are (thanks
to a time stamp). The easiest way to ensure uniqueness is with a 64bit
counter for each server. That will never cycle (if updated once a
nanosecond the last 584 years. A single NFS server would not handle
open/lock requests nearly that fast, and a Linux node is unlikely to
have an uptime approaching that).
This patch removes the 2 ida and instead uses a per-server
atomic64_t to provide uniqueness.
Note that the lock owner already encodes the id as 64 bits even though
it is a 32bit value. So changing to a 64bit value does not change the
encoding of the lock owner. The open owner encoding is now 4 bytes
larger.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Commit c77e22834a ("NFSv4: Fix a potential sleep while atomic in
nfs4_do_reclaim()") separate out the freeing of the state owners from
nfs4_purge_state_owners() and finish it outside the rcu lock.
However, the error path is omitted. As a result, the state owners in
"freeme" will not be released.
Fix it by adding freeing in the error path.
Fixes: c77e22834a ("NFSv4: Fix a potential sleep while atomic in nfs4_do_reclaim()")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Notable features of this release include:
- Pre-requisites for automatically determining the RPC server thread
count
- Clean-up and preparation for supporting LOCALIO, which will be
merged via the NFS client tree
- Enhancements and fixes to NFSv4.2 COPY offload
- A new Python-based tool for generating kernel SunRPC XDR encoding
and decoding functions, added as an aid for prototyping features
in protocols based on the Linux kernel's SunRPC implementation.
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-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd updates from Chuck Lever:
"Notable features of this release include:
- Pre-requisites for automatically determining the RPC server thread
count
- Clean-up and preparation for supporting LOCALIO, which will be
merged via the NFS client tree
- Enhancements and fixes to NFSv4.2 COPY offload
- A new Python-based tool for generating kernel SunRPC XDR encoding
and decoding functions, added as an aid for prototyping features in
protocols based on the Linux kernel's SunRPC implementation
As always I am grateful to the NFSD contributors, reviewers, testers,
and bug reporters who participated during this cycle"
* tag 'nfsd-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (57 commits)
xdrgen: Prevent reordering of encoder and decoder functions
xdrgen: typedefs should use the built-in string and opaque functions
xdrgen: Fix return code checking in built-in XDR decoders
tools: Add xdrgen
nfsd: fix delegation_blocked() to block correctly for at least 30 seconds
nfsd: fix initial getattr on write delegation
nfsd: untangle code in nfsd4_deleg_getattr_conflict()
nfsd: enforce upper limit for namelen in __cld_pipe_inprogress_downcall()
nfsd: return -EINVAL when namelen is 0
NFSD: Wrap async copy operations with trace points
NFSD: Clean up extra whitespace in trace_nfsd_copy_done
NFSD: Record the callback stateid in copy tracepoints
NFSD: Display copy stateids with conventional print formatting
NFSD: Limit the number of concurrent async COPY operations
NFSD: Async COPY result needs to return a write verifier
nfsd: avoid races with wake_up_var()
nfsd: use clear_and_wake_up_bit()
sunrpc: xprtrdma: Use ERR_CAST() to return
NFSD: Annotate struct pnfs_block_deviceaddr with __counted_by()
nfsd: call cache_put if xdr_reserve_space returns NULL
...
Notable features of this release include:
- Pre-requisites for automatically determining the RPC server thread
count
- Clean-up and preparation for supporting LOCALIO, which will be
merged via the NFS client tree
- Enhancements and fixes to NFSv4.2 COPY offload
- A new Python-based tool for generating kernel SunRPC XDR encoding
and decoding functions, added as an aid for prototyping features
in protocols based on the Linux kernel's SunRPC implementation.
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-6.12' into linux-next-with-localio
NFSD 6.12 Release Notes
Notable features of this release include:
- Pre-requisites for automatically determining the RPC server thread
count
- Clean-up and preparation for supporting LOCALIO, which will be
merged via the NFS client tree
- Enhancements and fixes to NFSv4.2 COPY offload
- A new Python-based tool for generating kernel SunRPC XDR encoding
and decoding functions, added as an aid for prototyping features
in protocols based on the Linux kernel's SunRPC implementation.
As always I am grateful to the NFSD contributors, reviewers,
testers, and bug reporters who participated during this cycle.
- Eliminate the writepage address space operation (by Matthew Wilcox).
- A syzkaller fix (by Julian Sun) and a minor cleanup (by Andreas
Gruenbacher).
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Merge tag 'gfs2-v6.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 update from Andreas Gruenbacher:
- Convert the writepage address space operation to writepages (Matthew
Wilcox)
- A syzkaller fix (by Julian Sun) and a minor cleanup (Andreas
Gruenbacher)
* tag 'gfs2-v6.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Remove gfs2_aspace_writepage()
gfs2: Remove gfs2_jdata_writepage()
gfs2: Remove __gfs2_writepage()
gfs2: Add gfs2_aspace_writepages()
gfs2: fix double destroy_workqueue error
gfs2: Minor gfs2_glock_cb cleanup
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Merge tag 'for-6.12-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix dangling pointer to rb-tree of defragmented inodes after cleanup
- a followup fix to handle concurrent lseek on the same fd that could
leak memory under some conditions
- fix wrong root id reported in tree checker when verifying dref
* tag 'for-6.12-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix use-after-free on rbtree that tracks inodes for auto defrag
btrfs: tree-checker: fix the wrong output of data backref objectid
btrfs: fix race setting file private on concurrent lseek using same fd
Avoid "gcc" since it is not the only compiler supported by Kbuild.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Building external modules is typically done using this command:
$ make -C <KERNEL_DIR> M=<EXTMOD_DIR>
Here, <KERNEL_DIR> refers to the output directory where the kernel was
built, not the kernel source directory.
When the kernel is built in the source tree, there is no ambiguity, as
the output directory and the source directory are the same.
If the kernel was built in a separate build directory, <KERNEL_DIR>
should be the kernel output directory. Otherwise, Kbuild cannot locate
necessary build artifacts. This has been the method for building
external modules against a pre-built kernel in a separate directory
for over 20 years. [1]
If you pass the kernel source directory to the -C option, you must also
specify the kernel build directory using the O= option. This approach
works as well, though it results in a slightly longer command:
$ make -C <KERNEL_SOURCE_DIR> O=<KERNEL_BUILD_DIR> M=<EXTMOD_DIR>
Some people mistakenly believe that O= should specify a build directory
for external modules when used together with M=. This commit adds more
clarification to Documentation/kbuild/kbuild.rst.
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=e321b2ec2eb2993b3d0116e5163c78ad923e3c54
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
The use of shipped files is discouraged in the upstream kernel these
days. [1]
Downstream Makefiles have the freedom to use shipped files or other
options to handle binaries, but this should not be advertised in the
upstream document.
[1]: https://lore.kernel.org/all/CAHk-=wgSEi_ZrHdqr=20xv+d6dr5G895CbOAi8ok+7-CQUN=fQ@mail.gmail.com/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Do similar to commit 1a4c1c9df7 ("docs/kbuild/makefiles: drop section
numbering, use references").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Do similar to commit 5e8f0ba38a ("docs/kbuild/makefiles: throw out the
local table of contents").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Kbuild used to manipulate header search paths, enforcing the odd
limitation of "no space after -I".
Commit cdd750bfb1 ("kbuild: remove 'addtree' and 'flags' magic for
header search paths") stopped doing that. This limitation no longer
exists. Instead, you need to accurately specify the header search path.
(In this case, $(src)/include)
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
