From ec3bc567eac12c557a2b99bd0b34b5dff12cab23 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 25 Jan 2022 08:26:31 -0500 Subject: [PATCH] libceph: new sparse_read op, support sparse reads on msgr2 crc codepath MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add support for a new sparse_read ceph_connection operation. The idea is that the client driver can define this operation use it to do special handling for incoming reads. The alloc_msg routine will look at the request and determine whether the reply is expected to be sparse. If it is, then we'll dispatch to a different set of state machine states that will repeatedly call the driver's sparse_read op to get length and placement info for reading the extent map, and the extents themselves. This necessitates adding some new field to some other structs: - The msg gets a new bool to track whether it's a sparse_read request. - A new field is added to the cursor to track the amount remaining in the current extent. This is used to cap the read from the socket into the msg_data - Handing a revoke with all of this is particularly difficult, so I've added a new data_len_remain field to the v2 connection info, and then use that to skip that much on a revoke. We may want to expand the use of that to the normal read path as well, just for consistency's sake. Signed-off-by: Jeff Layton Reviewed-by: Xiubo Li Reviewed-and-tested-by: Luís Henriques Reviewed-by: Milind Changire Signed-off-by: Ilya Dryomov --- include/linux/ceph/messenger.h | 28 +++++++ net/ceph/messenger.c | 1 + net/ceph/messenger_v2.c | 167 ++++++++++++++++++++++++++++++++++++++--- 3 files changed, 187 insertions(+), 9 deletions(-) diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h index 99c1726..8a6938f 100644 --- a/include/linux/ceph/messenger.h +++ b/include/linux/ceph/messenger.h @@ -17,6 +17,7 @@ struct ceph_msg; struct ceph_connection; +struct ceph_msg_data_cursor; /* * Ceph defines these callbacks for handling connection events. @@ -70,6 +71,30 @@ struct ceph_connection_operations { int used_proto, int result, const int *allowed_protos, int proto_cnt, const int *allowed_modes, int mode_cnt); + + /** + * sparse_read: read sparse data + * @con: connection we're reading from + * @cursor: data cursor for reading extents + * @buf: optional buffer to read into + * + * This should be called more than once, each time setting up to + * receive an extent into the current cursor position, and zeroing + * the holes between them. + * + * Returns amount of data to be read (in bytes), 0 if reading is + * complete, or -errno if there was an error. + * + * If @buf is set on a >0 return, then the data should be read into + * the provided buffer. Otherwise, it should be read into the cursor. + * + * The sparse read operation is expected to initialize the cursor + * with a length covering up to the end of the last extent. + */ + int (*sparse_read)(struct ceph_connection *con, + struct ceph_msg_data_cursor *cursor, + char **buf); + }; /* use format string %s%lld */ @@ -207,6 +232,7 @@ struct ceph_msg_data_cursor { struct ceph_msg_data *data; /* current data item */ size_t resid; /* bytes not yet consumed */ + int sr_resid; /* residual sparse_read len */ bool need_crc; /* crc update needed */ union { #ifdef CONFIG_BLOCK @@ -251,6 +277,7 @@ struct ceph_msg { struct kref kref; bool more_to_follow; bool needs_out_seq; + bool sparse_read; int front_alloc_len; struct ceph_msgpool *pool; @@ -395,6 +422,7 @@ struct ceph_connection_v2_info { void *conn_bufs[16]; int conn_buf_cnt; + int data_len_remain; struct kvec in_sign_kvecs[8]; struct kvec out_sign_kvecs[8]; diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 5eb4898..2eb10d7 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -1013,6 +1013,7 @@ void ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor, cursor->total_resid = length; cursor->data = msg->data; + cursor->sr_resid = 0; __ceph_msg_data_cursor_init(cursor); } diff --git a/net/ceph/messenger_v2.c b/net/ceph/messenger_v2.c index 1df1d29d..17c9a85 100644 --- a/net/ceph/messenger_v2.c +++ b/net/ceph/messenger_v2.c @@ -52,14 +52,16 @@ #define FRAME_LATE_STATUS_COMPLETE 0xe #define FRAME_LATE_STATUS_ABORTED_MASK 0xf -#define IN_S_HANDLE_PREAMBLE 1 -#define IN_S_HANDLE_CONTROL 2 -#define IN_S_HANDLE_CONTROL_REMAINDER 3 -#define IN_S_PREPARE_READ_DATA 4 -#define IN_S_PREPARE_READ_DATA_CONT 5 -#define IN_S_PREPARE_READ_ENC_PAGE 6 -#define IN_S_HANDLE_EPILOGUE 7 -#define IN_S_FINISH_SKIP 8 +#define IN_S_HANDLE_PREAMBLE 1 +#define IN_S_HANDLE_CONTROL 2 +#define IN_S_HANDLE_CONTROL_REMAINDER 3 +#define IN_S_PREPARE_READ_DATA 4 +#define IN_S_PREPARE_READ_DATA_CONT 5 +#define IN_S_PREPARE_READ_ENC_PAGE 6 +#define IN_S_PREPARE_SPARSE_DATA 7 +#define IN_S_PREPARE_SPARSE_DATA_CONT 8 +#define IN_S_HANDLE_EPILOGUE 9 +#define IN_S_FINISH_SKIP 10 #define OUT_S_QUEUE_DATA 1 #define OUT_S_QUEUE_DATA_CONT 2 @@ -1825,6 +1827,123 @@ static void prepare_read_data_cont(struct ceph_connection *con) con->v2.in_state = IN_S_HANDLE_EPILOGUE; } +static int prepare_sparse_read_cont(struct ceph_connection *con) +{ + int ret; + struct bio_vec bv; + char *buf = NULL; + struct ceph_msg_data_cursor *cursor = &con->v2.in_cursor; + + WARN_ON(con->v2.in_state != IN_S_PREPARE_SPARSE_DATA_CONT); + + if (iov_iter_is_bvec(&con->v2.in_iter)) { + if (ceph_test_opt(from_msgr(con->msgr), RXBOUNCE)) { + con->in_data_crc = crc32c(con->in_data_crc, + page_address(con->bounce_page), + con->v2.in_bvec.bv_len); + get_bvec_at(cursor, &bv); + memcpy_to_page(bv.bv_page, bv.bv_offset, + page_address(con->bounce_page), + con->v2.in_bvec.bv_len); + } else { + con->in_data_crc = ceph_crc32c_page(con->in_data_crc, + con->v2.in_bvec.bv_page, + con->v2.in_bvec.bv_offset, + con->v2.in_bvec.bv_len); + } + + ceph_msg_data_advance(cursor, con->v2.in_bvec.bv_len); + cursor->sr_resid -= con->v2.in_bvec.bv_len; + dout("%s: advance by 0x%x sr_resid 0x%x\n", __func__, + con->v2.in_bvec.bv_len, cursor->sr_resid); + WARN_ON_ONCE(cursor->sr_resid > cursor->total_resid); + if (cursor->sr_resid) { + get_bvec_at(cursor, &bv); + if (bv.bv_len > cursor->sr_resid) + bv.bv_len = cursor->sr_resid; + if (ceph_test_opt(from_msgr(con->msgr), RXBOUNCE)) { + bv.bv_page = con->bounce_page; + bv.bv_offset = 0; + } + set_in_bvec(con, &bv); + con->v2.data_len_remain -= bv.bv_len; + return 0; + } + } else if (iov_iter_is_kvec(&con->v2.in_iter)) { + /* On first call, we have no kvec so don't compute crc */ + if (con->v2.in_kvec_cnt) { + WARN_ON_ONCE(con->v2.in_kvec_cnt > 1); + con->in_data_crc = crc32c(con->in_data_crc, + con->v2.in_kvecs[0].iov_base, + con->v2.in_kvecs[0].iov_len); + } + } else { + return -EIO; + } + + /* get next extent */ + ret = con->ops->sparse_read(con, cursor, &buf); + if (ret <= 0) { + if (ret < 0) + return ret; + + reset_in_kvecs(con); + add_in_kvec(con, con->v2.in_buf, CEPH_EPILOGUE_PLAIN_LEN); + con->v2.in_state = IN_S_HANDLE_EPILOGUE; + return 0; + } + + if (buf) { + /* receive into buffer */ + reset_in_kvecs(con); + add_in_kvec(con, buf, ret); + con->v2.data_len_remain -= ret; + return 0; + } + + if (ret > cursor->total_resid) { + pr_warn("%s: ret 0x%x total_resid 0x%zx resid 0x%zx\n", + __func__, ret, cursor->total_resid, cursor->resid); + return -EIO; + } + get_bvec_at(cursor, &bv); + if (bv.bv_len > cursor->sr_resid) + bv.bv_len = cursor->sr_resid; + if (ceph_test_opt(from_msgr(con->msgr), RXBOUNCE)) { + if (unlikely(!con->bounce_page)) { + con->bounce_page = alloc_page(GFP_NOIO); + if (!con->bounce_page) { + pr_err("failed to allocate bounce page\n"); + return -ENOMEM; + } + } + + bv.bv_page = con->bounce_page; + bv.bv_offset = 0; + } + set_in_bvec(con, &bv); + con->v2.data_len_remain -= ret; + return ret; +} + +static int prepare_sparse_read_data(struct ceph_connection *con) +{ + struct ceph_msg *msg = con->in_msg; + + dout("%s: starting sparse read\n", __func__); + + if (WARN_ON_ONCE(!con->ops->sparse_read)) + return -EOPNOTSUPP; + + if (!con_secure(con)) + con->in_data_crc = -1; + + reset_in_kvecs(con); + con->v2.in_state = IN_S_PREPARE_SPARSE_DATA_CONT; + con->v2.data_len_remain = data_len(msg); + return prepare_sparse_read_cont(con); +} + static int prepare_read_tail_plain(struct ceph_connection *con) { struct ceph_msg *msg = con->in_msg; @@ -1845,7 +1964,10 @@ static int prepare_read_tail_plain(struct ceph_connection *con) } if (data_len(msg)) { - con->v2.in_state = IN_S_PREPARE_READ_DATA; + if (msg->sparse_read) + con->v2.in_state = IN_S_PREPARE_SPARSE_DATA; + else + con->v2.in_state = IN_S_PREPARE_READ_DATA; } else { add_in_kvec(con, con->v2.in_buf, CEPH_EPILOGUE_PLAIN_LEN); con->v2.in_state = IN_S_HANDLE_EPILOGUE; @@ -2898,6 +3020,12 @@ static int populate_in_iter(struct ceph_connection *con) prepare_read_enc_page(con); ret = 0; break; + case IN_S_PREPARE_SPARSE_DATA: + ret = prepare_sparse_read_data(con); + break; + case IN_S_PREPARE_SPARSE_DATA_CONT: + ret = prepare_sparse_read_cont(con); + break; case IN_S_HANDLE_EPILOGUE: ret = handle_epilogue(con); break; @@ -3489,6 +3617,23 @@ static void revoke_at_prepare_read_enc_page(struct ceph_connection *con) con->v2.in_state = IN_S_FINISH_SKIP; } +static void revoke_at_prepare_sparse_data(struct ceph_connection *con) +{ + int resid; /* current piece of data */ + int remaining; + + WARN_ON(con_secure(con)); + WARN_ON(!data_len(con->in_msg)); + WARN_ON(!iov_iter_is_bvec(&con->v2.in_iter)); + resid = iov_iter_count(&con->v2.in_iter); + dout("%s con %p resid %d\n", __func__, con, resid); + + remaining = CEPH_EPILOGUE_PLAIN_LEN + con->v2.data_len_remain; + con->v2.in_iter.count -= resid; + set_in_skip(con, resid + remaining); + con->v2.in_state = IN_S_FINISH_SKIP; +} + static void revoke_at_handle_epilogue(struct ceph_connection *con) { int resid; @@ -3505,6 +3650,7 @@ static void revoke_at_handle_epilogue(struct ceph_connection *con) void ceph_con_v2_revoke_incoming(struct ceph_connection *con) { switch (con->v2.in_state) { + case IN_S_PREPARE_SPARSE_DATA: case IN_S_PREPARE_READ_DATA: revoke_at_prepare_read_data(con); break; @@ -3514,6 +3660,9 @@ void ceph_con_v2_revoke_incoming(struct ceph_connection *con) case IN_S_PREPARE_READ_ENC_PAGE: revoke_at_prepare_read_enc_page(con); break; + case IN_S_PREPARE_SPARSE_DATA_CONT: + revoke_at_prepare_sparse_data(con); + break; case IN_S_HANDLE_EPILOGUE: revoke_at_handle_epilogue(con); break; -- 2.7.4