diff options
Diffstat (limited to 'net/sunrpc/xprtrdma/svc_rdma_pcl.c')
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_pcl.c | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_pcl.c b/net/sunrpc/xprtrdma/svc_rdma_pcl.c new file mode 100644 index 000000000..b63cfeaa2 --- /dev/null +++ b/net/sunrpc/xprtrdma/svc_rdma_pcl.c @@ -0,0 +1,306 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2020 Oracle. All rights reserved. + */ + +#include <linux/sunrpc/svc_rdma.h> +#include <linux/sunrpc/rpc_rdma.h> + +#include "xprt_rdma.h" +#include <trace/events/rpcrdma.h> + +/** + * pcl_free - Release all memory associated with a parsed chunk list + * @pcl: parsed chunk list + * + */ +void pcl_free(struct svc_rdma_pcl *pcl) +{ + while (!list_empty(&pcl->cl_chunks)) { + struct svc_rdma_chunk *chunk; + + chunk = pcl_first_chunk(pcl); + list_del(&chunk->ch_list); + kfree(chunk); + } +} + +static struct svc_rdma_chunk *pcl_alloc_chunk(u32 segcount, u32 position) +{ + struct svc_rdma_chunk *chunk; + + chunk = kmalloc(struct_size(chunk, ch_segments, segcount), GFP_KERNEL); + if (!chunk) + return NULL; + + chunk->ch_position = position; + chunk->ch_length = 0; + chunk->ch_payload_length = 0; + chunk->ch_segcount = 0; + return chunk; +} + +static struct svc_rdma_chunk * +pcl_lookup_position(struct svc_rdma_pcl *pcl, u32 position) +{ + struct svc_rdma_chunk *pos; + + pcl_for_each_chunk(pos, pcl) { + if (pos->ch_position == position) + return pos; + } + return NULL; +} + +static void pcl_insert_position(struct svc_rdma_pcl *pcl, + struct svc_rdma_chunk *chunk) +{ + struct svc_rdma_chunk *pos; + + pcl_for_each_chunk(pos, pcl) { + if (pos->ch_position > chunk->ch_position) + break; + } + __list_add(&chunk->ch_list, pos->ch_list.prev, &pos->ch_list); + pcl->cl_count++; +} + +static void pcl_set_read_segment(const struct svc_rdma_recv_ctxt *rctxt, + struct svc_rdma_chunk *chunk, + u32 handle, u32 length, u64 offset) +{ + struct svc_rdma_segment *segment; + + segment = &chunk->ch_segments[chunk->ch_segcount]; + segment->rs_handle = handle; + segment->rs_length = length; + segment->rs_offset = offset; + + trace_svcrdma_decode_rseg(&rctxt->rc_cid, chunk, segment); + + chunk->ch_length += length; + chunk->ch_segcount++; +} + +/** + * pcl_alloc_call - Construct a parsed chunk list for the Call body + * @rctxt: Ingress receive context + * @p: Start of an un-decoded Read list + * + * Assumptions: + * - The incoming Read list has already been sanity checked. + * - cl_count is already set to the number of segments in + * the un-decoded list. + * - The list might not be in order by position. + * + * Return values: + * %true: Parsed chunk list was successfully constructed, and + * cl_count is updated to be the number of chunks (ie. + * unique positions) in the Read list. + * %false: Memory allocation failed. + */ +bool pcl_alloc_call(struct svc_rdma_recv_ctxt *rctxt, __be32 *p) +{ + struct svc_rdma_pcl *pcl = &rctxt->rc_call_pcl; + unsigned int i, segcount = pcl->cl_count; + + pcl->cl_count = 0; + for (i = 0; i < segcount; i++) { + struct svc_rdma_chunk *chunk; + u32 position, handle, length; + u64 offset; + + p++; /* skip the list discriminator */ + p = xdr_decode_read_segment(p, &position, &handle, + &length, &offset); + if (position != 0) + continue; + + if (pcl_is_empty(pcl)) { + chunk = pcl_alloc_chunk(segcount, position); + if (!chunk) + return false; + pcl_insert_position(pcl, chunk); + } else { + chunk = list_first_entry(&pcl->cl_chunks, + struct svc_rdma_chunk, + ch_list); + } + + pcl_set_read_segment(rctxt, chunk, handle, length, offset); + } + + return true; +} + +/** + * pcl_alloc_read - Construct a parsed chunk list for normal Read chunks + * @rctxt: Ingress receive context + * @p: Start of an un-decoded Read list + * + * Assumptions: + * - The incoming Read list has already been sanity checked. + * - cl_count is already set to the number of segments in + * the un-decoded list. + * - The list might not be in order by position. + * + * Return values: + * %true: Parsed chunk list was successfully constructed, and + * cl_count is updated to be the number of chunks (ie. + * unique position values) in the Read list. + * %false: Memory allocation failed. + * + * TODO: + * - Check for chunk range overlaps + */ +bool pcl_alloc_read(struct svc_rdma_recv_ctxt *rctxt, __be32 *p) +{ + struct svc_rdma_pcl *pcl = &rctxt->rc_read_pcl; + unsigned int i, segcount = pcl->cl_count; + + pcl->cl_count = 0; + for (i = 0; i < segcount; i++) { + struct svc_rdma_chunk *chunk; + u32 position, handle, length; + u64 offset; + + p++; /* skip the list discriminator */ + p = xdr_decode_read_segment(p, &position, &handle, + &length, &offset); + if (position == 0) + continue; + + chunk = pcl_lookup_position(pcl, position); + if (!chunk) { + chunk = pcl_alloc_chunk(segcount, position); + if (!chunk) + return false; + pcl_insert_position(pcl, chunk); + } + + pcl_set_read_segment(rctxt, chunk, handle, length, offset); + } + + return true; +} + +/** + * pcl_alloc_write - Construct a parsed chunk list from a Write list + * @rctxt: Ingress receive context + * @pcl: Parsed chunk list to populate + * @p: Start of an un-decoded Write list + * + * Assumptions: + * - The incoming Write list has already been sanity checked, and + * - cl_count is set to the number of chunks in the un-decoded list. + * + * Return values: + * %true: Parsed chunk list was successfully constructed. + * %false: Memory allocation failed. + */ +bool pcl_alloc_write(struct svc_rdma_recv_ctxt *rctxt, + struct svc_rdma_pcl *pcl, __be32 *p) +{ + struct svc_rdma_segment *segment; + struct svc_rdma_chunk *chunk; + unsigned int i, j; + u32 segcount; + + for (i = 0; i < pcl->cl_count; i++) { + p++; /* skip the list discriminator */ + segcount = be32_to_cpup(p++); + + chunk = pcl_alloc_chunk(segcount, 0); + if (!chunk) + return false; + list_add_tail(&chunk->ch_list, &pcl->cl_chunks); + + for (j = 0; j < segcount; j++) { + segment = &chunk->ch_segments[j]; + p = xdr_decode_rdma_segment(p, &segment->rs_handle, + &segment->rs_length, + &segment->rs_offset); + trace_svcrdma_decode_wseg(&rctxt->rc_cid, chunk, j); + + chunk->ch_length += segment->rs_length; + chunk->ch_segcount++; + } + } + return true; +} + +static int pcl_process_region(const struct xdr_buf *xdr, + unsigned int offset, unsigned int length, + int (*actor)(const struct xdr_buf *, void *), + void *data) +{ + struct xdr_buf subbuf; + + if (!length) + return 0; + if (xdr_buf_subsegment(xdr, &subbuf, offset, length)) + return -EMSGSIZE; + return actor(&subbuf, data); +} + +/** + * pcl_process_nonpayloads - Process non-payload regions inside @xdr + * @pcl: Chunk list to process + * @xdr: xdr_buf to process + * @actor: Function to invoke on each non-payload region + * @data: Arguments for @actor + * + * This mechanism must ignore not only result payloads that were already + * sent via RDMA Write, but also XDR padding for those payloads that + * the upper layer has added. + * + * Assumptions: + * The xdr->len and ch_position fields are aligned to 4-byte multiples. + * + * Returns: + * On success, zero, + * %-EMSGSIZE on XDR buffer overflow, or + * The return value of @actor + */ +int pcl_process_nonpayloads(const struct svc_rdma_pcl *pcl, + const struct xdr_buf *xdr, + int (*actor)(const struct xdr_buf *, void *), + void *data) +{ + struct svc_rdma_chunk *chunk, *next; + unsigned int start; + int ret; + + chunk = pcl_first_chunk(pcl); + + /* No result payloads were generated */ + if (!chunk || !chunk->ch_payload_length) + return actor(xdr, data); + + /* Process the region before the first result payload */ + ret = pcl_process_region(xdr, 0, chunk->ch_position, actor, data); + if (ret < 0) + return ret; + + /* Process the regions between each middle result payload */ + while ((next = pcl_next_chunk(pcl, chunk))) { + if (!next->ch_payload_length) + break; + + start = pcl_chunk_end_offset(chunk); + ret = pcl_process_region(xdr, start, next->ch_position - start, + actor, data); + if (ret < 0) + return ret; + + chunk = next; + } + + /* Process the region after the last result payload */ + start = pcl_chunk_end_offset(chunk); + ret = pcl_process_region(xdr, start, xdr->len - start, actor, data); + if (ret < 0) + return ret; + + return 0; +} |