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Diffstat (limited to '')
| -rw-r--r-- | net/rds/message.c | 522 |
1 files changed, 522 insertions, 0 deletions
diff --git a/net/rds/message.c b/net/rds/message.c new file mode 100644 index 000000000..8fa3d19c2 --- /dev/null +++ b/net/rds/message.c @@ -0,0 +1,522 @@ +/* + * Copyright (c) 2006, 2020 Oracle and/or its affiliates. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + */ +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <linux/skbuff.h> +#include <linux/list.h> +#include <linux/errqueue.h> + +#include "rds.h" + +static unsigned int rds_exthdr_size[__RDS_EXTHDR_MAX] = { +[RDS_EXTHDR_NONE] = 0, +[RDS_EXTHDR_VERSION] = sizeof(struct rds_ext_header_version), +[RDS_EXTHDR_RDMA] = sizeof(struct rds_ext_header_rdma), +[RDS_EXTHDR_RDMA_DEST] = sizeof(struct rds_ext_header_rdma_dest), +[RDS_EXTHDR_NPATHS] = sizeof(u16), +[RDS_EXTHDR_GEN_NUM] = sizeof(u32), +}; + +void rds_message_addref(struct rds_message *rm) +{ + rdsdebug("addref rm %p ref %d\n", rm, refcount_read(&rm->m_refcount)); + refcount_inc(&rm->m_refcount); +} +EXPORT_SYMBOL_GPL(rds_message_addref); + +static inline bool rds_zcookie_add(struct rds_msg_zcopy_info *info, u32 cookie) +{ + struct rds_zcopy_cookies *ck = &info->zcookies; + int ncookies = ck->num; + + if (ncookies == RDS_MAX_ZCOOKIES) + return false; + ck->cookies[ncookies] = cookie; + ck->num = ++ncookies; + return true; +} + +static struct rds_msg_zcopy_info *rds_info_from_znotifier(struct rds_znotifier *znotif) +{ + return container_of(znotif, struct rds_msg_zcopy_info, znotif); +} + +void rds_notify_msg_zcopy_purge(struct rds_msg_zcopy_queue *q) +{ + unsigned long flags; + LIST_HEAD(copy); + struct rds_msg_zcopy_info *info, *tmp; + + spin_lock_irqsave(&q->lock, flags); + list_splice(&q->zcookie_head, ©); + INIT_LIST_HEAD(&q->zcookie_head); + spin_unlock_irqrestore(&q->lock, flags); + + list_for_each_entry_safe(info, tmp, ©, rs_zcookie_next) { + list_del(&info->rs_zcookie_next); + kfree(info); + } +} + +static void rds_rm_zerocopy_callback(struct rds_sock *rs, + struct rds_znotifier *znotif) +{ + struct rds_msg_zcopy_info *info; + struct rds_msg_zcopy_queue *q; + u32 cookie = znotif->z_cookie; + struct rds_zcopy_cookies *ck; + struct list_head *head; + unsigned long flags; + + mm_unaccount_pinned_pages(&znotif->z_mmp); + q = &rs->rs_zcookie_queue; + spin_lock_irqsave(&q->lock, flags); + head = &q->zcookie_head; + if (!list_empty(head)) { + info = list_first_entry(head, struct rds_msg_zcopy_info, + rs_zcookie_next); + if (rds_zcookie_add(info, cookie)) { + spin_unlock_irqrestore(&q->lock, flags); + kfree(rds_info_from_znotifier(znotif)); + /* caller invokes rds_wake_sk_sleep() */ + return; + } + } + + info = rds_info_from_znotifier(znotif); + ck = &info->zcookies; + memset(ck, 0, sizeof(*ck)); + WARN_ON(!rds_zcookie_add(info, cookie)); + list_add_tail(&info->rs_zcookie_next, &q->zcookie_head); + + spin_unlock_irqrestore(&q->lock, flags); + /* caller invokes rds_wake_sk_sleep() */ +} + +/* + * This relies on dma_map_sg() not touching sg[].page during merging. + */ +static void rds_message_purge(struct rds_message *rm) +{ + unsigned long i, flags; + bool zcopy = false; + + if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags))) + return; + + spin_lock_irqsave(&rm->m_rs_lock, flags); + if (rm->m_rs) { + struct rds_sock *rs = rm->m_rs; + + if (rm->data.op_mmp_znotifier) { + zcopy = true; + rds_rm_zerocopy_callback(rs, rm->data.op_mmp_znotifier); + rds_wake_sk_sleep(rs); + rm->data.op_mmp_znotifier = NULL; + } + sock_put(rds_rs_to_sk(rs)); + rm->m_rs = NULL; + } + spin_unlock_irqrestore(&rm->m_rs_lock, flags); + + for (i = 0; i < rm->data.op_nents; i++) { + /* XXX will have to put_page for page refs */ + if (!zcopy) + __free_page(sg_page(&rm->data.op_sg[i])); + else + put_page(sg_page(&rm->data.op_sg[i])); + } + rm->data.op_nents = 0; + + if (rm->rdma.op_active) + rds_rdma_free_op(&rm->rdma); + if (rm->rdma.op_rdma_mr) + kref_put(&rm->rdma.op_rdma_mr->r_kref, __rds_put_mr_final); + + if (rm->atomic.op_active) + rds_atomic_free_op(&rm->atomic); + if (rm->atomic.op_rdma_mr) + kref_put(&rm->atomic.op_rdma_mr->r_kref, __rds_put_mr_final); +} + +void rds_message_put(struct rds_message *rm) +{ + rdsdebug("put rm %p ref %d\n", rm, refcount_read(&rm->m_refcount)); + WARN(!refcount_read(&rm->m_refcount), "danger refcount zero on %p\n", rm); + if (refcount_dec_and_test(&rm->m_refcount)) { + BUG_ON(!list_empty(&rm->m_sock_item)); + BUG_ON(!list_empty(&rm->m_conn_item)); + rds_message_purge(rm); + + kfree(rm); + } +} +EXPORT_SYMBOL_GPL(rds_message_put); + +void rds_message_populate_header(struct rds_header *hdr, __be16 sport, + __be16 dport, u64 seq) +{ + hdr->h_flags = 0; + hdr->h_sport = sport; + hdr->h_dport = dport; + hdr->h_sequence = cpu_to_be64(seq); + hdr->h_exthdr[0] = RDS_EXTHDR_NONE; +} +EXPORT_SYMBOL_GPL(rds_message_populate_header); + +int rds_message_add_extension(struct rds_header *hdr, unsigned int type, + const void *data, unsigned int len) +{ + unsigned int ext_len = sizeof(u8) + len; + unsigned char *dst; + + /* For now, refuse to add more than one extension header */ + if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE) + return 0; + + if (type >= __RDS_EXTHDR_MAX || len != rds_exthdr_size[type]) + return 0; + + if (ext_len >= RDS_HEADER_EXT_SPACE) + return 0; + dst = hdr->h_exthdr; + + *dst++ = type; + memcpy(dst, data, len); + + dst[len] = RDS_EXTHDR_NONE; + return 1; +} +EXPORT_SYMBOL_GPL(rds_message_add_extension); + +/* + * If a message has extension headers, retrieve them here. + * Call like this: + * + * unsigned int pos = 0; + * + * while (1) { + * buflen = sizeof(buffer); + * type = rds_message_next_extension(hdr, &pos, buffer, &buflen); + * if (type == RDS_EXTHDR_NONE) + * break; + * ... + * } + */ +int rds_message_next_extension(struct rds_header *hdr, + unsigned int *pos, void *buf, unsigned int *buflen) +{ + unsigned int offset, ext_type, ext_len; + u8 *src = hdr->h_exthdr; + + offset = *pos; + if (offset >= RDS_HEADER_EXT_SPACE) + goto none; + + /* Get the extension type and length. For now, the + * length is implied by the extension type. */ + ext_type = src[offset++]; + + if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX) + goto none; + ext_len = rds_exthdr_size[ext_type]; + if (offset + ext_len > RDS_HEADER_EXT_SPACE) + goto none; + + *pos = offset + ext_len; + if (ext_len < *buflen) + *buflen = ext_len; + memcpy(buf, src + offset, *buflen); + return ext_type; + +none: + *pos = RDS_HEADER_EXT_SPACE; + *buflen = 0; + return RDS_EXTHDR_NONE; +} + +int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset) +{ + struct rds_ext_header_rdma_dest ext_hdr; + + ext_hdr.h_rdma_rkey = cpu_to_be32(r_key); + ext_hdr.h_rdma_offset = cpu_to_be32(offset); + return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr)); +} +EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension); + +/* + * Each rds_message is allocated with extra space for the scatterlist entries + * rds ops will need. This is to minimize memory allocation count. Then, each rds op + * can grab SGs when initializing its part of the rds_message. + */ +struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp) +{ + struct rds_message *rm; + + if (extra_len > KMALLOC_MAX_SIZE - sizeof(struct rds_message)) + return NULL; + + rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp); + if (!rm) + goto out; + + rm->m_used_sgs = 0; + rm->m_total_sgs = extra_len / sizeof(struct scatterlist); + + refcount_set(&rm->m_refcount, 1); + INIT_LIST_HEAD(&rm->m_sock_item); + INIT_LIST_HEAD(&rm->m_conn_item); + spin_lock_init(&rm->m_rs_lock); + init_waitqueue_head(&rm->m_flush_wait); + +out: + return rm; +} + +/* + * RDS ops use this to grab SG entries from the rm's sg pool. + */ +struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents) +{ + struct scatterlist *sg_first = (struct scatterlist *) &rm[1]; + struct scatterlist *sg_ret; + + if (nents <= 0) { + pr_warn("rds: alloc sgs failed! nents <= 0\n"); + return ERR_PTR(-EINVAL); + } + + if (rm->m_used_sgs + nents > rm->m_total_sgs) { + pr_warn("rds: alloc sgs failed! total %d used %d nents %d\n", + rm->m_total_sgs, rm->m_used_sgs, nents); + return ERR_PTR(-ENOMEM); + } + + sg_ret = &sg_first[rm->m_used_sgs]; + sg_init_table(sg_ret, nents); + rm->m_used_sgs += nents; + + return sg_ret; +} + +struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len) +{ + struct rds_message *rm; + unsigned int i; + int num_sgs = DIV_ROUND_UP(total_len, PAGE_SIZE); + int extra_bytes = num_sgs * sizeof(struct scatterlist); + + rm = rds_message_alloc(extra_bytes, GFP_NOWAIT); + if (!rm) + return ERR_PTR(-ENOMEM); + + set_bit(RDS_MSG_PAGEVEC, &rm->m_flags); + rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len); + rm->data.op_nents = DIV_ROUND_UP(total_len, PAGE_SIZE); + rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs); + if (IS_ERR(rm->data.op_sg)) { + void *err = ERR_CAST(rm->data.op_sg); + rds_message_put(rm); + return err; + } + + for (i = 0; i < rm->data.op_nents; ++i) { + sg_set_page(&rm->data.op_sg[i], + virt_to_page(page_addrs[i]), + PAGE_SIZE, 0); + } + + return rm; +} + +static int rds_message_zcopy_from_user(struct rds_message *rm, struct iov_iter *from) +{ + struct scatterlist *sg; + int ret = 0; + int length = iov_iter_count(from); + int total_copied = 0; + struct rds_msg_zcopy_info *info; + + rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from)); + + /* + * now allocate and copy in the data payload. + */ + sg = rm->data.op_sg; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + INIT_LIST_HEAD(&info->rs_zcookie_next); + rm->data.op_mmp_znotifier = &info->znotif; + if (mm_account_pinned_pages(&rm->data.op_mmp_znotifier->z_mmp, + length)) { + ret = -ENOMEM; + goto err; + } + while (iov_iter_count(from)) { + struct page *pages; + size_t start; + ssize_t copied; + + copied = iov_iter_get_pages(from, &pages, PAGE_SIZE, + 1, &start); + if (copied < 0) { + struct mmpin *mmp; + int i; + + for (i = 0; i < rm->data.op_nents; i++) + put_page(sg_page(&rm->data.op_sg[i])); + mmp = &rm->data.op_mmp_znotifier->z_mmp; + mm_unaccount_pinned_pages(mmp); + ret = -EFAULT; + goto err; + } + total_copied += copied; + iov_iter_advance(from, copied); + length -= copied; + sg_set_page(sg, pages, copied, start); + rm->data.op_nents++; + sg++; + } + WARN_ON_ONCE(length != 0); + return ret; +err: + kfree(info); + rm->data.op_mmp_znotifier = NULL; + return ret; +} + +int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from, + bool zcopy) +{ + unsigned long to_copy, nbytes; + unsigned long sg_off; + struct scatterlist *sg; + int ret = 0; + + rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from)); + + /* now allocate and copy in the data payload. */ + sg = rm->data.op_sg; + sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */ + + if (zcopy) + return rds_message_zcopy_from_user(rm, from); + + while (iov_iter_count(from)) { + if (!sg_page(sg)) { + ret = rds_page_remainder_alloc(sg, iov_iter_count(from), + GFP_HIGHUSER); + if (ret) + return ret; + rm->data.op_nents++; + sg_off = 0; + } + + to_copy = min_t(unsigned long, iov_iter_count(from), + sg->length - sg_off); + + rds_stats_add(s_copy_from_user, to_copy); + nbytes = copy_page_from_iter(sg_page(sg), sg->offset + sg_off, + to_copy, from); + if (nbytes != to_copy) + return -EFAULT; + + sg_off += to_copy; + + if (sg_off == sg->length) + sg++; + } + + return ret; +} + +int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to) +{ + struct rds_message *rm; + struct scatterlist *sg; + unsigned long to_copy; + unsigned long vec_off; + int copied; + int ret; + u32 len; + + rm = container_of(inc, struct rds_message, m_inc); + len = be32_to_cpu(rm->m_inc.i_hdr.h_len); + + sg = rm->data.op_sg; + vec_off = 0; + copied = 0; + + while (iov_iter_count(to) && copied < len) { + to_copy = min_t(unsigned long, iov_iter_count(to), + sg->length - vec_off); + to_copy = min_t(unsigned long, to_copy, len - copied); + + rds_stats_add(s_copy_to_user, to_copy); + ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off, + to_copy, to); + if (ret != to_copy) + return -EFAULT; + + vec_off += to_copy; + copied += to_copy; + + if (vec_off == sg->length) { + vec_off = 0; + sg++; + } + } + + return copied; +} + +/* + * If the message is still on the send queue, wait until the transport + * is done with it. This is particularly important for RDMA operations. + */ +void rds_message_wait(struct rds_message *rm) +{ + wait_event_interruptible(rm->m_flush_wait, + !test_bit(RDS_MSG_MAPPED, &rm->m_flags)); +} + +void rds_message_unmapped(struct rds_message *rm) +{ + clear_bit(RDS_MSG_MAPPED, &rm->m_flags); + wake_up_interruptible(&rm->m_flush_wait); +} +EXPORT_SYMBOL_GPL(rds_message_unmapped); |