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path: root/include/linux/sunrpc
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2018-09-30SUNRPC: Replace krb5_seq_lock with a lockless schemeTrond Myklebust
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Unexport xdr_partial_copy_from_skb()Trond Myklebust
It is no longer used outside of net/sunrpc/socklib.c Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Allow AF_LOCAL sockets to use the generic stream receiveTrond Myklebust
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Simplify TCP receive code by switching to using iteratorsTrond Myklebust
Most of this code should also be reusable with other socket types. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Add a bvec array to struct xdr_buf for use with iovec_iter()Trond Myklebust
Add a bvec array to struct xdr_buf, and have the client allocate it when we need to receive data into pages. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Add a label for RPC calls that require allocation on receiveTrond Myklebust
If the RPC call relies on the receive call allocating pages as buffers, then let's label it so that we a) Don't leak memory by allocating pages for requests that do not expect this behaviour b) Can optimise for the common case where calls do not require allocation. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Fix priority queue fairnessTrond Myklebust
Fix up the priority queue to not batch by owner, but by queue, so that we allow '1 << priority' elements to be dequeued before switching to the next priority queue. The owner field is still used to wake up requests in round robin order by owner to avoid single processes hogging the RPC layer by loading the queues. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Convert xprt receive queue to use an rbtreeTrond Myklebust
If the server is slow, we can find ourselves with quite a lot of entries on the receive queue. Converting the search from an O(n) to O(log(n)) can make a significant difference, particularly since we have to hold a number of locks while searching. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Cleanup: remove the unused 'task' argument from the request_send()Trond Myklebust
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Clean up transport write space handlingTrond Myklebust
Treat socket write space handling in the same way we now treat transport congestion: by denying the XPRT_LOCK until the transport signals that it has free buffer space. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Turn off throttling of RPC slots for TCP socketsTrond Myklebust
The theory was that we would need to grab the socket lock anyway, so we might as well use it to gate the allocation of RPC slots for a TCP socket. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Support for congestion control when queuing is enabledTrond Myklebust
Both RDMA and UDP transports require the request to get a "congestion control" credit before they can be transmitted. Right now, this is done when the request locks the socket. We'd like it to happen when a request attempts to be transmitted for the first time. In order to support retransmission of requests that already hold such credits, we also want to ensure that they get queued first, so that we don't deadlock with requests that have yet to obtain a credit. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Improve latency for interactive tasksTrond Myklebust
One of the intentions with the priority queues was to ensure that no single process can hog the transport. The field task->tk_owner therefore identifies the RPC call's origin, and is intended to allow the RPC layer to organise queues for fairness. This commit therefore modifies the transmit queue to group requests by task->tk_owner, and ensures that we round robin among those groups. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Treat the task and request as separate in the xprt_ops->send_request()Trond Myklebust
When we shift to using the transmit queue, then the task that holds the write lock will not necessarily be the same as the one being transmitted. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Fix up the back channel transmitTrond Myklebust
Fix up the back channel code to recognise that it has already been transmitted, so does not need to be called again. Also ensure that we set req->rq_task. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Refactor RPC call encodingTrond Myklebust
Move the call encoding so that it occurs before the transport connection etc. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Add a transmission queue for RPC requestsTrond Myklebust
Add the queue that will enforce the ordering of RPC task transmission. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Distinguish between the slot allocation list and receive queueTrond Myklebust
When storing a struct rpc_rqst on the slot allocation list, we currently use the same field 'rq_list' as we use to store the request on the receive queue. Since the structure is never on both lists at the same time, this is OK. However, for clarity, let's make that a union with different names for the different lists so that we can more easily distinguish between the two states. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Refactor xprt_transmit() to remove wait for reply codeTrond Myklebust
Allow the caller in clnt.c to call into the code to wait for a reply after calling xprt_transmit(). Again, the reason is that the backchannel code does not need this functionality. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Refactor xprt_transmit() to remove the reply queue codeTrond Myklebust
Separate out the action of adding a request to the reply queue so that the backchannel code can simply skip calling it altogether. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Rename xprt->recv_lock to xprt->queue_lockTrond Myklebust
We will use the same lock to protect both the transmit and receive queues. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Add a helper to wake up a sleeping rpc_task and set its statusTrond Myklebust
Add a helper that will wake up a task that is sleeping on a specific queue, and will set the value of task->tk_status. This is mainly intended for use by the transport layer to notify the task of an error condition. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Refactor the transport request pinningTrond Myklebust
We are going to need to pin for both send and receive. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Add socket transmit queue offset trackingTrond Myklebust
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Rename TCP receive-specific state variablesTrond Myklebust
Since we will want to introduce similar TCP state variables for the transmission of requests, let's rename the existing ones to label that they are for the receive side. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Simplify identification of when the message send/receive is completeTrond Myklebust
Add states to indicate that the message send and receive are not yet complete. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: The transmitted message must lie in the RPCSEC window of validityTrond Myklebust
If a message has been encoded using RPCSEC_GSS, the server is maintaining a window of sequence numbers that it considers valid. The client should normally be tracking that window, and needs to verify that the sequence number used by the message being transmitted still lies inside the window of validity. So far, we've been able to assume this condition would be realised automatically, since the client has been encoding the message only after taking the socket lock. Once we change that condition, we will need the explicit check. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Clean up initialisation of the struct rpc_rqstTrond Myklebust
Move the initialisation back into xprt.c. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-28gss_krb5: Remove VLA usage of skcipherKees Cook
In the quest to remove all stack VLA usage from the kernel[1], this replaces struct crypto_skcipher and SKCIPHER_REQUEST_ON_STACK() usage with struct crypto_sync_skcipher and SYNC_SKCIPHER_REQUEST_ON_STACK(), which uses a fixed stack size. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Anna Schumaker <anna.schumaker@netapp.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: YueHaibing <yuehaibing@huawei.com> Cc: linux-nfs@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-08-23Merge tag 'nfs-for-4.19-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds
Pull NFS client updates from Anna Schumaker: "These patches include adding async support for the v4.2 COPY operation. I think Bruce is planning to send the server patches for the next release, but I figured we could get the client side out of the way now since it's been in my tree for a while. This shouldn't cause any problems, since the server will still respond with synchronous copies even if the client requests async. Features: - Add support for asynchronous server-side COPY operations Stable bufixes: - Fix an off-by-one in bl_map_stripe() (v3.17+) - NFSv4 client live hangs after live data migration recovery (v4.9+) - xprtrdma: Fix disconnect regression (v4.18+) - Fix locking in pnfs_generic_recover_commit_reqs (v4.14+) - Fix a sleep in atomic context in nfs4_callback_sequence() (v4.9+) Other bugfixes and cleanups: - Optimizations and fixes involving NFS v4.1 / pNFS layout handling - Optimize lseek(fd, SEEK_CUR, 0) on directories to avoid locking - Immediately reschedule writeback when the server replies with an error - Fix excessive attribute revalidation in nfs_execute_ok() - Add error checking to nfs_idmap_prepare_message() - Use new vm_fault_t return type - Return a delegation when reclaiming one that the server has recalled - Referrals should inherit proto setting from parents - Make rpc_auth_create_args a const - Improvements to rpc_iostats tracking - Fix a potential reference leak when there is an error processing a callback - Fix rmdir / mkdir / rename nlink accounting - Fix updating inode change attribute - Fix error handling in nfsn4_sp4_select_mode() - Use an appropriate work queue for direct-write completion - Don't busy wait if NFSv4 session draining is interrupted" * tag 'nfs-for-4.19-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (54 commits) pNFS: Remove unwanted optimisation of layoutget pNFS/flexfiles: ff_layout_pg_init_read should exit on error pNFS: Treat RECALLCONFLICT like DELAY... pNFS: When updating the stateid in layoutreturn, also update the recall range NFSv4: Fix a sleep in atomic context in nfs4_callback_sequence() NFSv4: Fix locking in pnfs_generic_recover_commit_reqs NFSv4: Fix a typo in nfs4_init_channel_attrs() NFSv4: Don't busy wait if NFSv4 session draining is interrupted NFS recover from destination server reboot for copies NFS add a simple sync nfs4_proc_commit after async COPY NFS handle COPY ERR_OFFLOAD_NO_REQS NFS send OFFLOAD_CANCEL when COPY killed NFS export nfs4_async_handle_error NFS handle COPY reply CB_OFFLOAD call race NFS add support for asynchronous COPY NFS COPY xdr handle async reply NFS OFFLOAD_CANCEL xdr NFS CB_OFFLOAD xdr NFS: Use an appropriate work queue for direct-write completion NFSv4: Fix error handling in nfs4_sp4_select_mode() ...
2018-08-22sunrpc: Extract target name into svc_credChuck Lever
NFSv4.0 callback needs to know the GSS target name the client used when it established its lease. That information is available from the GSS context created by gssproxy. Make it available in each svc_cred. Note this will also give us access to the real target service principal name (which is typically "nfs", but spec does not require that). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-08-09NFSD: Handle full-length symlinksChuck Lever
I've given up on the idea of zero-copy handling of SYMLINK on the server side. This is because the Linux VFS symlink API requires the symlink pathname to be in a NUL-terminated kmalloc'd buffer. The NUL-termination is going to be problematic (watching out for landing on a page boundary and dealing with a 4096-byte pathname). I don't believe that SYMLINK creation is on a performance path or is requested frequently enough that it will cause noticeable CPU cache pollution due to data copies. There will be two places where a transport callout will be necessary to fill in the rqstp: one will be in the svc_fill_symlink_pathname() helper that is used by NFSv2 and NFSv3, and the other will be in nfsd4_decode_create(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-08-09NFSD: Refactor the generic write vector fill helperChuck Lever
fill_in_write_vector() is nearly the same logic as svc_fill_write_vector(), but there are a few differences so that the former can handle multiple WRITE payloads in a single COMPOUND. svc_fill_write_vector() can be adjusted so that it can be used in the NFSv4 WRITE code path too. Instead of assuming the pages are coming from rq_args.pages, have the caller pass in the page list. The immediate benefit is a reduction of code duplication. It also prevents the NFSv4 WRITE decoder from passing an empty vector element when the transport has provided the payload in the xdr_buf's page array. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-07-31NFSv4 client live hangs after live data migration recoveryBill Baker
After a live data migration event at the NFS server, the client may send I/O requests to the wrong server, causing a live hang due to repeated recovery events. On the wire, this will appear as an I/O request failing with NFS4ERR_BADSESSION, followed by successful CREATE_SESSION, repeatedly. NFS4ERR_BADSSESSION is returned because the session ID being used was issued by the other server and is not valid at the old server. The failure is caused by async worker threads having cached the transport (xprt) in the rpc_task structure. After the migration recovery completes, the task is redispatched and the task resends the request to the wrong server based on the old value still present in tk_xprt. The solution is to recompute the tk_xprt field of the rpc_task structure so that the request goes to the correct server. Signed-off-by: Bill Baker <bill.baker@oracle.com> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Helen Chao <helen.chao@oracle.com> Fixes: fb43d17210ba ("SUNRPC: Use the multipath iterator to assign a ...") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-07-31sunrpc: Change rpc_print_iostats to rpc_clnt_show_stats and handle rpc_clnt ↵Dave Wysochanski
clones The existing rpc_print_iostats has a few shortcomings. First, the naming is not consistent with other functions in the kernel that display stats. Second, it is really displaying stats for an rpc_clnt structure as it displays both xprt stats and per-op stats. Third, it does not handle rpc_clnt clones, which is important for the one in-kernel tree caller of this function, the NFS client's nfs_show_stats function. Fix all of the above by renaming the rpc_print_iostats to rpc_clnt_show_stats and looping through any rpc_clnt clones via cl_parent. Once this interface is fixed, this addresses a problem with NFSv4. Before this patch, the /proc/self/mountstats always showed incorrect counts for NFSv4 lease and session related opcodes such as SEQUENCE, RENEW, SETCLIENTID, CREATE_SESSION, etc. These counts were always 0 even though many ops would go over the wire. The reason for this is there are multiple rpc_clnt structures allocated for any given NFSv4 mount, and inside nfs_show_stats() we callled into rpc_print_iostats() which only handled one of them, nfs_server->client. Fix these counts by calling sunrpc's new rpc_clnt_show_stats() function, which handles cloned rpc_clnt structs and prints the stats together. Note that one side-effect of the above is that multiple mounts from the same NFS server will show identical counts in the above ops due to the fact the one rpc_clnt (representing the NFSv4 client state) is shared across mounts. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-07-30net/sunrpc: Make rpc_auth_create_args a constSargun Dhillon
This turns rpc_auth_create_args into a const as it gets passed through the auth stack. Signed-off-by: Sargun Dhillon <sargun@sargun.me> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-06-12Merge tag 'nfs-for-4.18-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client updates from Trond Myklebust: "Highlights include: Stable fixes: - Fix a 1-byte stack overflow in nfs_idmap_read_and_verify_message - Fix a hang due to incorrect error returns in rpcrdma_convert_iovs() - Revert an incorrect change to the NFSv4.1 callback channel - Fix a bug in the NFSv4.1 sequence error handling Features and optimisations: - Support for piggybacking a LAYOUTGET operation to the OPEN compound - RDMA performance enhancements to deal with transport congestion - Add proper SPDX tags for NetApp-contributed RDMA source - Do not request delegated file attributes (size+change) from the server - Optimise away a GETATTR in the lookup revalidate code when doing NFSv4 OPEN - Optimise away unnecessary lookups for rename targets - Misc performance improvements when freeing NFSv4 delegations Bugfixes and cleanups: - Try to fail quickly if proto=rdma - Clean up RDMA receive trace points - Fix sillyrename to return the delegation when appropriate - Misc attribute revalidation fixes - Immediately clear the pNFS layout on a file when the server returns ESTALE - Return NFS4ERR_DELAY when delegation/layout recalls fail due to igrab() - Fix the client behaviour on NFS4ERR_SEQ_FALSE_RETRY" * tag 'nfs-for-4.18-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (80 commits) skip LAYOUTRETURN if layout is invalid NFSv4.1: Fix the client behaviour on NFS4ERR_SEQ_FALSE_RETRY NFSv4: Fix a typo in nfs41_sequence_process NFSv4: Revert commit 5f83d86cf531d ("NFSv4.x: Fix wraparound issues..") NFSv4: Return NFS4ERR_DELAY when a layout recall fails due to igrab() NFSv4: Return NFS4ERR_DELAY when a delegation recall fails due to igrab() NFSv4.0: Remove transport protocol name from non-UCS client ID NFSv4.0: Remove cl_ipaddr from non-UCS client ID NFSv4: Fix a compiler warning when CONFIG_NFS_V4_1 is undefined NFS: Filter cache invalidation when holding a delegation NFS: Ignore NFS_INO_REVAL_FORCED in nfs_check_inode_attributes() NFS: Improve caching while holding a delegation NFS: Fix attribute revalidation NFS: fix up nfs_setattr_update_inode NFSv4: Ensure the inode is clean when we set a delegation NFSv4: Ignore NFS_INO_REVAL_FORCED in nfs4_proc_access NFSv4: Don't ask for delegated attributes when adding a hard link NFSv4: Don't ask for delegated attributes when revalidating the inode NFS: Pass the inode down to the getattr() callback NFSv4: Don't request size+change attribute if they are delegated to us ...
2018-06-12Merge tag 'nfsd-4.18' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
Pull nfsd updates from Bruce Fields: "A relatively quiet cycle for nfsd. The largest piece is an RDMA update from Chuck Lever with new trace points, miscellaneous cleanups, and streamlining of the send and receive paths. Other than that, some miscellaneous bugfixes" * tag 'nfsd-4.18' of git://linux-nfs.org/~bfields/linux: (26 commits) nfsd: fix error handling in nfs4_set_delegation() nfsd: fix potential use-after-free in nfsd4_decode_getdeviceinfo Fix 16-byte memory leak in gssp_accept_sec_context_upcall svcrdma: Fix incorrect return value/type in svc_rdma_post_recvs svcrdma: Remove unused svc_rdma_op_ctxt svcrdma: Persistently allocate and DMA-map Send buffers svcrdma: Simplify svc_rdma_send() svcrdma: Remove post_send_wr svcrdma: Don't overrun the SGE array in svc_rdma_send_ctxt svcrdma: Introduce svc_rdma_send_ctxt svcrdma: Clean up Send SGE accounting svcrdma: Refactor svc_rdma_dma_map_buf svcrdma: Allocate recv_ctxt's on CPU handling Receives svcrdma: Persistently allocate and DMA-map Receive buffers svcrdma: Preserve Receive buffer until svc_rdma_sendto svcrdma: Simplify svc_rdma_recv_ctxt_put svcrdma: Remove sc_rq_depth svcrdma: Introduce svc_rdma_recv_ctxt svcrdma: Trace key RDMA API events svcrdma: Trace key RPC/RDMA protocol events ...
2018-05-11svcrdma: Remove unused svc_rdma_op_ctxtChuck Lever
Clean up: Eliminate a structure that is no longer used. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Persistently allocate and DMA-map Send buffersChuck Lever
While sending each RPC Reply, svc_rdma_sendto allocates and DMA- maps a separate buffer where the RPC/RDMA transport header is constructed. The buffer is unmapped and released in the Send completion handler. This is significant per-RPC overhead, especially for small RPCs. Instead, allocate and DMA-map a buffer, and cache it in each svc_rdma_send_ctxt. This buffer and its mapping can be re-used for each RPC, saving the cost of memory allocation and DMA mapping. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Remove post_send_wrChuck Lever
Clean up: Now that the send_wr is part of the svc_rdma_send_ctxt, svc_rdma_post_send_wr is nearly empty. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Don't overrun the SGE array in svc_rdma_send_ctxtChuck Lever
Receive buffers are always the same size, but each Send WR has a variable number of SGEs, based on the contents of the xdr_buf being sent. While assembling a Send WR, keep track of the number of SGEs so that we don't exceed the device's maximum, or walk off the end of the Send SGE array. For now the Send path just fails if it exceeds the maximum. The current logic in svc_rdma_accept bases the maximum number of Send SGEs on the largest NFS request that can be sent or received. In the transport layer, the limit is actually based on the capabilities of the underlying device, not on properties of the Upper Layer Protocol. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Introduce svc_rdma_send_ctxtChuck Lever
svc_rdma_op_ctxt's are pre-allocated and maintained on a per-xprt free list. This eliminates the overhead of calling kmalloc / kfree, both of which grab a globally shared lock that disables interrupts. Introduce a replacement to svc_rdma_op_ctxt's that is built especially for the svcrdma Send path. Subsequent patches will take advantage of this new structure by allocating real resources which are then cached in these objects. The allocations are freed when the transport is torn down. I've renamed the structure so that static type checking can be used to ensure that uses of op_ctxt and send_ctxt are not confused. As an additional clean up, structure fields are renamed to conform with kernel coding conventions. Additional clean ups: - Handle svc_rdma_send_ctxt_get allocation failure at each call site, rather than pre-allocating and hoping we guessed correctly - All send_ctxt_put call-sites request page freeing, so remove the @free_pages argument - All send_ctxt_put call-sites unmap SGEs, so fold that into svc_rdma_send_ctxt_put Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Clean up Send SGE accountingChuck Lever
Clean up: Since there's already a svc_rdma_op_ctxt being passed around with the running count of mapped SGEs, drop unneeded parameters to svc_rdma_post_send_wr(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Refactor svc_rdma_dma_map_bufChuck Lever
Clean up: svc_rdma_dma_map_buf does mostly the same thing as svc_rdma_dma_map_page, so let's fold these together. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Allocate recv_ctxt's on CPU handling ReceivesChuck Lever
There is a significant latency penalty when processing an ingress Receive if the Receive buffer resides in memory that is not on the same NUMA node as the the CPU handling completions for a CQ. The system administrator and the device driver determine which CPU handles completions. This CPU does not change during life of the CQ. Further the Upper Layer does not have any visibility of which CPU it is. Allocating Receive buffers in the Receive completion handler guarantees that Receive buffers are allocated on the preferred NUMA node for that CQ. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Persistently allocate and DMA-map Receive buffersChuck Lever
The current Receive path uses an array of pages which are allocated and DMA mapped when each Receive WR is posted, and then handed off to the upper layer in rqstp::rq_arg. The page flip releases unused pages in the rq_pages pagelist. This mechanism introduces a significant amount of overhead. So instead, kmalloc the Receive buffer, and leave it DMA-mapped while the transport remains connected. This confers a number of benefits: * Each Receive WR requires only one receive SGE, no matter how large the inline threshold is. This helps the server-side NFS/RDMA transport operate on less capable RDMA devices. * The Receive buffer is left allocated and mapped all the time. This relieves svc_rdma_post_recv from the overhead of allocating and DMA-mapping a fresh buffer. * svc_rdma_wc_receive no longer has to DMA unmap the Receive buffer. It has to DMA sync only the number of bytes that were received. * svc_rdma_build_arg_xdr no longer has to free a page in rq_pages for each page in the Receive buffer, making it a constant-time function. * The Receive buffer is now plugged directly into the rq_arg's head[0].iov_vec, and can be larger than a page without spilling over into rq_arg's page list. This enables simplification of the RDMA Read path in subsequent patches. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Simplify svc_rdma_recv_ctxt_putChuck Lever
Currently svc_rdma_recv_ctxt_put's callers have to know whether they want to free the ctxt's pages or not. This means the human developers have to know when and why to set that free_pages argument. Instead, the ctxt should carry that information with it so that svc_rdma_recv_ctxt_put does the right thing no matter who is calling. We want to keep track of the number of pages in the Receive buffer separately from the number of pages pulled over by RDMA Read. This is so that the correct number of pages can be freed properly and that number is well-documented. So now, rc_hdr_count is the number of pages consumed by head[0] (ie., the page index where the Read chunk should start); and rc_page_count is always the number of pages that need to be released when the ctxt is put. The @free_pages argument is no longer needed. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Remove sc_rq_depthChuck Lever
Clean up: No need to retain rq_depth in struct svcrdma_xprt, it is used only in svc_rdma_accept(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Introduce svc_rdma_recv_ctxtChuck Lever
svc_rdma_op_ctxt's are pre-allocated and maintained on a per-xprt free list. This eliminates the overhead of calling kmalloc / kfree, both of which grab a globally shared lock that disables interrupts. To reduce contention further, separate the use of these objects in the Receive and Send paths in svcrdma. Subsequent patches will take advantage of this separation by allocating real resources which are then cached in these objects. The allocations are freed when the transport is torn down. I've renamed the structure so that static type checking can be used to ensure that uses of op_ctxt and recv_ctxt are not confused. As an additional clean up, structure fields are renamed to conform with kernel coding conventions. As a final clean up, helpers related to recv_ctxt are moved closer to the functions that use them. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>