Clean up: Pass in just the piece of the svc_rqst that is needed
here.
While we're in the area, add an informative documenting comment.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Sometimes we might have a RCU managed credential pointer and don't want
to use locking to handle it. Add a function that will take a reference
to the cred iff the refcount is not already zero. Callers can dereference
the pointer under the rcu_read_lock and use that function to take a
reference only if the cred is not on its way to destruction.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Add function rpc_lookup_generic_cred, which allows lookups of a generic
credential that's not current_cred().
[jlayton: add gfp_t parm]
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
We need to be able to call the generic_cred creator from different
contexts. Add a gfp_t parm to the crcreate operation and to
rpcauth_lookup_credcache. For now, we just push the gfp_t parms up
one level to the *_lookup_cred functions.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Pull nfsd updates from Bruce Fields:
"Various bugfixes, a RDMA update from Chuck Lever, and support for a
new pnfs layout type from Christoph Hellwig. The new layout type is a
variant of the block layout which uses SCSI features to offer improved
fencing and device identification.
(Also: note this pull request also includes the client side of SCSI
layout, with Trond's permission.)"
* tag 'nfsd-4.6' of git://linux-nfs.org/~bfields/linux:
sunrpc/cache: drop reference when sunrpc_cache_pipe_upcall() detects a race
nfsd: recover: fix memory leak
nfsd: fix deadlock secinfo+readdir compound
nfsd4: resfh unused in nfsd4_secinfo
svcrdma: Use new CQ API for RPC-over-RDMA server send CQs
svcrdma: Use new CQ API for RPC-over-RDMA server receive CQs
svcrdma: Remove close_out exit path
svcrdma: Hook up the logic to return ERR_CHUNK
svcrdma: Use correct XID in error replies
svcrdma: Make RDMA_ERROR messages work
rpcrdma: Add RPCRDMA_HDRLEN_ERR
svcrdma: svc_rdma_post_recv() should close connection on error
svcrdma: Close connection when a send error occurs
nfsd: Lower NFSv4.1 callback message size limit
svcrdma: Do not send Write chunk XDR pad with inline content
svcrdma: Do not write xdr_buf::tail in a Write chunk
svcrdma: Find client-provided write and reply chunks once per reply
nfsd: Update NFS server comments related to RDMA support
nfsd: Fix a memory leak when meeting unsupported state_protect_how4
nfsd4: fix bad bounds checking
Pull NFS client updates from Trond Myklebust:
"Highlights include:
Features:
- Add support for multiple NFSv4.1 callbacks in flight
- Initial patchset for RPC multipath support
- Adapt RPC/RDMA to use the new completion queue API
Bugfixes and cleanups:
- nfs4: nfs4_ff_layout_prepare_ds should return NULL if connection failed
- Cleanups to remove nfs_inode_dio_wait and nfs4_file_fsync
- Fix RPC/RDMA credit accounting
- Properly handle RDMA_ERROR replies
- xprtrdma: Do not wait if ib_post_send() fails
- xprtrdma: Segment head and tail XDR buffers on page boundaries
- xprtrdma cleanups for dprintk, physical_op_map and unused macros"
* tag 'nfs-for-4.6-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (35 commits)
nfs/blocklayout: make sure making a aligned read request
nfs4: nfs4_ff_layout_prepare_ds should return NULL if connection failed
nfs: remove nfs_inode_dio_wait
nfs: remove nfs4_file_fsync
xprtrdma: Use new CQ API for RPC-over-RDMA client send CQs
xprtrdma: Use an anonymous union in struct rpcrdma_mw
xprtrdma: Use new CQ API for RPC-over-RDMA client receive CQs
xprtrdma: Serialize credit accounting again
xprtrdma: Properly handle RDMA_ERROR replies
rpcrdma: Add RPCRDMA_HDRLEN_ERR
xprtrdma: Do not wait if ib_post_send() fails
xprtrdma: Segment head and tail XDR buffers on page boundaries
xprtrdma: Clean up dprintk format string containing a newline
xprtrdma: Clean up physical_op_map()
xprtrdma: Clean up unused RPCRDMA_INLINE_PAD_THRESH macro
NFS add callback_ops to nfs4_proc_bind_conn_to_session_callback
pnfs/NFSv4.1: Add multipath capabilities to pNFS flexfiles servers over NFSv3
SUNRPC: Allow addition of new transports to a struct rpc_clnt
NFSv4.1: nfs4_proc_bind_conn_to_session must iterate over all connections
SUNRPC: Make NFS swap work with multipath
...
NFS: NFSoRDMA Client Side Changes
These patches include several bugfixes and cleanups for the NFSoRDMA client.
This includes bugfixes for NFS v4.1, proper RDMA_ERROR handling, and fixes
from the recent workqueue swicchover. These patches also switch xprtrdma to
use the new CQ API
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* tag 'nfs-rdma-4.6-1' of git://git.linux-nfs.org/projects/anna/nfs-rdma: (787 commits)
xprtrdma: Use new CQ API for RPC-over-RDMA client send CQs
xprtrdma: Use an anonymous union in struct rpcrdma_mw
xprtrdma: Use new CQ API for RPC-over-RDMA client receive CQs
xprtrdma: Serialize credit accounting again
xprtrdma: Properly handle RDMA_ERROR replies
rpcrdma: Add RPCRDMA_HDRLEN_ERR
xprtrdma: Do not wait if ib_post_send() fails
xprtrdma: Segment head and tail XDR buffers on page boundaries
xprtrdma: Clean up dprintk format string containing a newline
xprtrdma: Clean up physical_op_map()
xprtrdma: Clean up unused RPCRDMA_INLINE_PAD_THRESH macro
Error headers are shorter than either RDMA_MSG or RDMA_NOMSG.
Since HDRLEN_MIN is already used in several other places that would
be annoying to change, add RPCRDMA_HDRLEN_ERR for the one or two
spots where the shorter length is needed.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Calling ib_poll_cq() to sort through WCs during a completion is a
common pattern amongst RDMA consumers. Since commit 14d3a3b249
("IB: add a proper completion queue abstraction"), WC sorting can
be handled by the IB core.
By converting to this new API, svcrdma is made a better neighbor to
other RDMA consumers, as it allows the core to schedule the delivery
of completions more fairly amongst all active consumers.
This new API also aims each completion at a function that is
specific to the WR's opcode. Thus the ctxt->wr_op field and the
switch in process_context is replaced by a set of methods that
handle each completion type.
Because each ib_cqe carries a pointer to a completion method, the
core can now post operations on a consumer's QP, and handle the
completions itself.
The server's rdma_stat_sq_poll and rdma_stat_sq_prod metrics are no
longer updated.
As a clean up, the cq_event_handler, the dto_tasklet, and all
associated locking is removed, as they are no longer referenced or
used.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Calling ib_poll_cq() to sort through WCs during a completion is a
common pattern amongst RDMA consumers. Since commit 14d3a3b249
("IB: add a proper completion queue abstraction"), WC sorting can
be handled by the IB core.
By converting to this new API, svcrdma is made a better neighbor to
other RDMA consumers, as it allows the core to schedule the delivery
of completions more fairly amongst all active consumers.
Because each ib_cqe carries a pointer to a completion method, the
core can now post operations on a consumer's QP, and handle the
completions itself.
svcrdma receive completions no longer use the dto_tasklet. Each
polled Receive WC is now handled individually in soft IRQ context.
The server transport's rdma_stat_rq_poll and rdma_stat_rq_prod
metrics are no longer updated.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When constructing an error reply, svc_rdma_xdr_encode_error()
needs to view the client's request message so it can get the
failing request's XID.
svc_rdma_xdr_decode_req() is supposed to return a pointer to the
client's request header. But if it fails to decode the client's
message (and thus an error reply is needed) it does not return the
pointer. The server then sends a bogus XID in the error reply.
Instead, unconditionally generate the pointer to the client's header
in svc_rdma_recvfrom(), and pass that pointer to both functions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Tested-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Fix several issues with svc_rdma_send_error():
- Post a receive buffer to replace the one that was consumed by
the incoming request
- Posting a send should use DMA_TO_DEVICE, not DMA_FROM_DEVICE
- No need to put_page _and_ free pages in svc_rdma_put_context
- Make sure the sge is set up completely in case the error
path goes through svc_rdma_unmap_dma()
- Replace the use of ENOSYS, which has a reserved meaning
Related fixes in svc_rdma_recvfrom():
- Don't leak the ctxt associated with the incoming request
- Don't close the connection after sending an error reply
- Let svc_rdma_send_error() figure out the right header error code
As a last clean up, move svc_rdma_send_error() to svc_rdma_sendto.c
with other similar functions. There is some common logic in these
functions that could someday be combined to reduce code duplication.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Tested-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Error headers are shorter than either RDMA_MSG or RDMA_NOMSG.
Since HDRLEN_MIN is already used in several other places that would
be annoying to change, add RPCRDMA_HDRLEN_ERR for the one or two
spots where the shorter length is needed.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The maximum size of a backchannel message on RPC-over-RDMA depends
on the connection's inline threshold. Today that threshold is
typically 1024 bytes, making the maximum message size 996 bytes.
The Linux server's CREATE_SESSION operation checks that the size
of callback Calls can be as large as 1044 bytes, to accommodate
RPCSEC_GSS. Thus CREATE_SESSION fails if a client advertises the
true message size maximum of 996 bytes.
But the server's backchannel currently does not support RPCSEC_GSS.
The actual maximum size it needs is much smaller. It is safe to
reduce the limit to enable NFSv4.1 on RDMA backchannel operation.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The NFS server's XDR encoders adds an XDR pad for content in the
xdr_buf page list at the beginning of the xdr_buf's tail buffer.
On RDMA transports, Write chunks are sent separately and without an
XDR pad.
If a Write chunk is being sent, strip off the pad in the tail buffer
so that inline content following the Write chunk remains XDR-aligned
when it is sent to the client.
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=294
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Add a function to allow creation and addition of a new transport
to an existing rpc_clnt
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Add a helper for tasks that require us to apply a function to all the
transports in an rpc_clnt.
An example of a usecase would be BIND_CONN_TO_SESSION, where we want
to send one RPC call down each transport.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This is needed in order to allow the NFSv4.1 backchannel and
BIND_CONN_TO_SESSION function to work.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This is a pre-patch for the RPC multipath code. It sets up the storage in
struct rpc_clnt for the multipath code.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
In order to support multipathing/trunking we will need the ability to
track multiple transports. This patch sets up a basic structure for
doing so.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This patch replaces uses of blkcipher with skcipher and the long
obsolete hash interface with either shash (for non-SG users) and
ahash.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull rdma updates from Doug Ledford:
"Initial roundup of 4.5 merge window patches
- Remove usage of ib_query_device and instead store attributes in
ib_device struct
- Move iopoll out of block and into lib, rename to irqpoll, and use
in several places in the rdma stack as our new completion queue
polling library mechanism. Update the other block drivers that
already used iopoll to use the new mechanism too.
- Replace the per-entry GID table locks with a single GID table lock
- IPoIB multicast cleanup
- Cleanups to the IB MR facility
- Add support for 64bit extended IB counters
- Fix for netlink oops while parsing RDMA nl messages
- RoCEv2 support for the core IB code
- mlx4 RoCEv2 support
- mlx5 RoCEv2 support
- Cross Channel support for mlx5
- Timestamp support for mlx5
- Atomic support for mlx5
- Raw QP support for mlx5
- MAINTAINERS update for mlx4/mlx5
- Misc ocrdma, qib, nes, usNIC, cxgb3, cxgb4, mlx4, mlx5 updates
- Add support for remote invalidate to the iSER driver (pushed
through the RDMA tree due to dependencies, acknowledged by nab)
- Update to NFSoRDMA (pushed through the RDMA tree due to
dependencies, acknowledged by Bruce)"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (169 commits)
IB/mlx5: Unify CQ create flags check
IB/mlx5: Expose Raw Packet QP to user space consumers
{IB, net}/mlx5: Move the modify QP operation table to mlx5_ib
IB/mlx5: Support setting Ethernet priority for Raw Packet QPs
IB/mlx5: Add Raw Packet QP query functionality
IB/mlx5: Add create and destroy functionality for Raw Packet QP
IB/mlx5: Refactor mlx5_ib_qp to accommodate other QP types
IB/mlx5: Allocate a Transport Domain for each ucontext
net/mlx5_core: Warn on unsupported events of QP/RQ/SQ
net/mlx5_core: Add RQ and SQ event handling
net/mlx5_core: Export transport objects
IB/mlx5: Expose CQE version to user-space
IB/mlx5: Add CQE version 1 support to user QPs and SRQs
IB/mlx5: Fix data validation in mlx5_ib_alloc_ucontext
IB/sa: Fix netlink local service GFP crash
IB/srpt: Remove redundant wc array
IB/qib: Improve ipoib UD performance
IB/mlx4: Advertise RoCE v2 support
IB/mlx4: Create and use another QP1 for RoCEv2
IB/mlx4: Enable send of RoCE QP1 packets with IP/UDP headers
...
To support the server-side of an NFSv4.1 backchannel on RDMA
connections, add a transport class that enables backward
direction messages on an existing forward channel connection.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Bruce Fields <bfields@fieldses.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Extra resources for handling backchannel requests have to be
pre-allocated when a transport instance is created. Set up
additional fields in svcxprt_rdma to track these resources.
The max_requests fields are elements of the RPC-over-RDMA
protocol, so they should be u32. To ensure that unsigned
arithmetic is used everywhere, some other fields in the
svcxprt_rdma struct are updated.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Bruce Fields <bfields@fieldses.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
svc_rdma_post_recv() allocates pages for receive buffers on-demand.
It uses GFP_KERNEL so the allocator tries hard, and may sleep. But
I'm about to add a call to svc_rdma_post_recv() from a function
that may not sleep.
Since all svc_rdma_post_recv() call sites can tolerate its failure,
allow it to fail if the page allocator returns nothing. Longer term,
receive buffers, being a finite resource per-connection, should be
pre-allocated and re-used.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Bruce Fields <bfields@fieldses.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
To ensure this allocation cannot fail and will not sleep,
pre-allocate the req_map structures per-connection.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Bruce Fields <bfields@fieldses.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
When the maximum payload size of NFS READ and WRITE was increased
by commit cc9a903d91 ("svcrdma: Change maximum server payload back
to RPCSVC_MAXPAYLOAD"), the size of struct svc_rdma_op_ctxt
increased to over 6KB (on x86_64). That makes allocating one of
these from a kmem_cache more likely to fail in situations when
system memory is exhausted.
Since I'm about to add a caller where this allocation must always
work _and_ it cannot sleep, pre-allocate ctxts for each connection.
Another motivation for this change is that NFSv4.x servers are
required by specification not to drop NFS requests. Pre-allocating
memory resources reduces the likelihood of a drop.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Bruce Fields <bfields@fieldses.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Add a function svc_age_temp_xprts_now() to close temporary transports
whose xpt_local matches the address passed in server_addr immediately
instead of waiting for them to be closed by the timer function.
The function is intended to be used by notifier_blocks that will be
added to nfsd and lockd that will run when an ip address is deleted.
This will eliminate the ACK storms and client hangs that occur in
HA-NFS configurations where nfsd & lockd is left running on the cluster
nodes all the time and the NFS 'service' is migrated back and forth
within a short timeframe.
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The principal name on a gss cred is used to setup the NFSv4.0 callback,
which has to have a client principal name to authenticate to.
That code wants the name to be in the form servicetype@hostname.
rpc.svcgssd passes down such names (and passes down no principal name at
all in the case the principal isn't a service principal).
gss-proxy always passes down the principal name, and passes it down in
the form servicetype/hostname@REALM. So we've been munging the name
gss-proxy passes down into the format the NFSv4.0 callback code expects,
or throwing away the name if we can't.
Since the introduction of the MACH_CRED enforcement in NFSv4.1, we've
also been using the principal name to verify that certain operations are
done as the same principal as was used on the original EXCHANGE_ID call.
For that application, the original name passed down by gss-proxy is also
useful.
Lack of that name in some cases was causing some kerberized NFSv4.1
mount failures in an Active Directory environment.
This fix only works in the gss-proxy case. The fix for legacy
rpc.svcgssd would be more involved, and rpc.svcgssd already has other
problems in the AD case.
Reported-and-tested-by: James Ralston <ralston@pobox.com>
Acked-by: Simo Sorce <simo@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull nfsd updates from Bruce Fields:
"Apologies for coming a little late in the merge window. Fortunately
this is another fairly quiet one:
Mainly smaller bugfixes and cleanup. We're still finding some bugs
from the breakup of the big NFSv4 state lock in 3.17 -- thanks
especially to Andrew Elble and Jeff Layton for tracking down some of
the remaining races"
* tag 'nfsd-4.4' of git://linux-nfs.org/~bfields/linux:
svcrpc: document lack of some memory barriers
nfsd: fix race with open / open upgrade stateids
nfsd: eliminate sending duplicate and repeated delegations
nfsd: remove recurring workqueue job to clean DRC
SUNRPC: drop stale comment in svc_setup_socket()
nfsd: ensure that seqid morphing operations are atomic wrt to copies
nfsd: serialize layout stateid morphing operations
nfsd: improve client_has_state to check for unused openowners
nfsd: fix clid_inuse on mount with security change
sunrpc/cache: make cache flushing more reliable.
nfsd: move include of state.h from trace.c to trace.h
sunrpc: avoid warning in gss_key_timeout
lockd: get rid of reference-counted NSM RPC clients
SUNRPC: Use MSG_SENDPAGE_NOTLAST when calling sendpage()
lockd: create NSM handles per net namespace
nfsd: switch unsigned char flags in svc_fh to bools
nfsd: move svc_fh->fh_maxsize to just after fh_handle
nfsd: drop null test before destroy functions
nfsd: serialize state seqid morphing operations
Pull NFS client updates from Trond Myklebust:
"Highlights include:
New features:
- RDMA client backchannel from Chuck
- Support for NFSv4.2 file CLONE using the btrfs ioctl
Bugfixes + cleanups:
- Move socket data receive out of the bottom halves and into a
workqueue
- Refactor NFSv4 error handling so synchronous and asynchronous RPC
handles errors identically.
- Fix a panic when blocks or object layouts reads return a bad data
length
- Fix nfsroot so it can handle a 1024 byte long path.
- Fix bad usage of page offset in bl_read_pagelist
- Various NFSv4 callback cleanups+fixes
- Fix GETATTR bitmap verification
- Support hexadecimal number for sunrpc debug sysctl files"
* tag 'nfs-for-4.4-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (53 commits)
Sunrpc: Supports hexadecimal number for sysctl files of sunrpc debug
nfs: Fix GETATTR bitmap verification
nfs: Remove unused xdr page offsets in getacl/setacl arguments
fs/nfs: remove unnecessary new_valid_dev check
SUNRPC: fix variable type
NFS: Enable client side NFSv4.1 backchannel to use other transports
pNFS/flexfiles: Add support for FF_FLAGS_NO_IO_THRU_MDS
pNFS/flexfiles: When mirrored, retry failed reads by switching mirrors
SUNRPC: Remove the TCP-only restriction in bc_svc_process()
svcrdma: Add backward direction service for RPC/RDMA transport
xprtrdma: Handle incoming backward direction RPC calls
xprtrdma: Add support for sending backward direction RPC replies
xprtrdma: Pre-allocate Work Requests for backchannel
xprtrdma: Pre-allocate backward rpc_rqst and send/receive buffers
SUNRPC: Abstract backchannel operations
xprtrdma: Saving IRQs no longer needed for rb_lock
xprtrdma: Remove reply tasklet
xprtrdma: Use workqueue to process RPC/RDMA replies
xprtrdma: Replace send and receive arrays
xprtrdma: Refactor reply handler error handling
...
NFS: NFSoRDMA Client Side Changes
In addition to a variety of bugfixes, these patches are mostly geared at
enabling both swap and backchannel support to the NFS over RDMA client.
Signed-off-by: Anna Schumake <Anna.Schumaker@Netapp.com>
Forechannel transports get their own "bc_up" method to create an
endpoint for the backchannel service.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
[Anna Schumaker: Add forward declaration of struct net to xprt.h]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
xprt_{setup,destroy}_backchannel() won't be adequate for RPC/RMDA
bi-direction. In particular, receive buffers have to be pre-
registered and posted in order to receive incoming backchannel
requests.
Add a virtual function call to allow the insertion of appropriate
backchannel setup and destruction methods for each transport.
In addition, freeing a backchannel request is a little different
for RPC/RDMA. Introduce an rpc_xprt_op to handle the difference.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Tested-By: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The caches used to store sunrpc authentication information can be
flushed by writing a timestamp to a file in /proc.
This timestamp has a one-second resolution and any entry in cache that
was last_refreshed *before* that time is treated as expired.
This is problematic as it is not possible to reliably flush the cache
without interrupting NFS service.
If the current time is written to the "flush" file, any entry that was
added since the current second started will still be treated as valid.
If one second beyond than the current time is written to the file
then no entries can be valid until the second ticks over. This will
mean that no NFS request will be handled for up to 1 second.
To resolve this issue we make two changes:
1/ treat an entry as expired if the timestamp when it was last_refreshed
is before *or the same as* the expiry time. This means that current
code which writes out the current time will now flush the cache
reliably.
2/ when a new entry in added to the cache - set the last_refresh timestamp
to 1 second *beyond* the current flush time, when that not in the
past.
This ensures that newly added entries will always be valid.
Now that we have a very reliable way to flush the cache, and also
since we are using "since-boot" timestamps which are monotonic,
change cache_purge() to set the smallest future flush_time which
will work, and leave it there: don't revert to '1'.
Also disable the setting of the 'flush_time' far into the future.
That has never been useful and is now awkward as it would cause
last_refresh times to be strange.
Finally: if a request is made to set the 'flush_time' to the current
second, assume the intent is to flush the cache and advance it, if
necessary, to 1 second beyond the current 'flush_time' so that all
active entries will be deemed to be expired.
As part of this we need to add a 'cache_detail' arg to cache_init()
and cache_fresh_locked() so they can find the current ->flush_time.
Signed-off-by: NeilBrown <neilb@suse.com>
Reported-by: Olaf Kirch <okir@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Stream protocols such as TCP can often build up a backlog of data to be
read due to ordering. Combine this with the fact that some workloads such
as NFS read()-intensive workloads need to receive a lot of data per RPC
call, and it turns out that receiving the data from inside a softirq
context can cause starvation.
The following patch moves the TCP data receive into a workqueue context.
We still end up calling tcp_read_sock(), but we do so from a process
context, meaning that softirqs are enabled for most of the time.
With this patch, I see a doubling of read bandwidth when running a
multi-threaded iozone workload between a virtual client and server setup.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
