diff options
| -rw-r--r-- | drivers/scsi/Makefile | 2 | ||||
| -rw-r--r-- | drivers/scsi/iscsi_tcp.c | 1524 | ||||
| -rw-r--r-- | drivers/scsi/iscsi_tcp.h | 71 |
3 files changed, 259 insertions, 1338 deletions
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile index 72fd5043cfa..b89aedfa9ed 100644 --- a/drivers/scsi/Makefile +++ b/drivers/scsi/Makefile @@ -36,7 +36,7 @@ obj-$(CONFIG_SCSI_SAS_LIBSAS) += libsas/ obj-$(CONFIG_SCSI_SRP_ATTRS) += scsi_transport_srp.o obj-$(CONFIG_SCSI_DH) += device_handler/ -obj-$(CONFIG_ISCSI_TCP) += libiscsi.o iscsi_tcp.o +obj-$(CONFIG_ISCSI_TCP) += libiscsi.o libiscsi_tcp.o iscsi_tcp.o obj-$(CONFIG_INFINIBAND_ISER) += libiscsi.o obj-$(CONFIG_SCSI_A4000T) += 53c700.o a4000t.o obj-$(CONFIG_SCSI_ZORRO7XX) += 53c700.o zorro7xx.o diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c index 97f3f68aeb6..07d9eb14721 100644 --- a/drivers/scsi/iscsi_tcp.c +++ b/drivers/scsi/iscsi_tcp.c @@ -27,7 +27,6 @@ */ #include <linux/types.h> -#include <linux/list.h> #include <linux/inet.h> #include <linux/file.h> #include <linux/blkdev.h> @@ -44,12 +43,12 @@ #include "iscsi_tcp.h" -MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, " +MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, " + "Dmitry Yusupov <dmitry_yus@yahoo.com>, " "Alex Aizman <itn780@yahoo.com>"); MODULE_DESCRIPTION("iSCSI/TCP data-path"); MODULE_LICENSE("GPL"); #undef DEBUG_TCP -#define DEBUG_ASSERT #ifdef DEBUG_TCP #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt) @@ -57,924 +56,22 @@ MODULE_LICENSE("GPL"); #define debug_tcp(fmt...) #endif -static struct scsi_transport_template *iscsi_tcp_scsi_transport; -static struct scsi_host_template iscsi_sht; -static struct iscsi_transport iscsi_tcp_transport; +static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport; +static struct scsi_host_template iscsi_sw_tcp_sht; +static struct iscsi_transport iscsi_sw_tcp_transport; static unsigned int iscsi_max_lun = 512; module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO); -static int iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn, - struct iscsi_segment *segment); - -/* - * Scatterlist handling: inside the iscsi_segment, we - * remember an index into the scatterlist, and set data/size - * to the current scatterlist entry. For highmem pages, we - * kmap as needed. - * - * Note that the page is unmapped when we return from - * TCP's data_ready handler, so we may end up mapping and - * unmapping the same page repeatedly. The whole reason - * for this is that we shouldn't keep the page mapped - * outside the softirq. - */ - -/** - * iscsi_tcp_segment_init_sg - init indicated scatterlist entry - * @segment: the buffer object - * @sg: scatterlist - * @offset: byte offset into that sg entry - * - * This function sets up the segment so that subsequent - * data is copied to the indicated sg entry, at the given - * offset. - */ -static inline void -iscsi_tcp_segment_init_sg(struct iscsi_segment *segment, - struct scatterlist *sg, unsigned int offset) -{ - segment->sg = sg; - segment->sg_offset = offset; - segment->size = min(sg->length - offset, - segment->total_size - segment->total_copied); - segment->data = NULL; -} - -/** - * iscsi_tcp_segment_map - map the current S/G page - * @segment: iscsi_segment - * @recv: 1 if called from recv path - * - * We only need to possibly kmap data if scatter lists are being used, - * because the iscsi passthrough and internal IO paths will never use high - * mem pages. - */ -static inline void -iscsi_tcp_segment_map(struct iscsi_segment *segment, int recv) -{ - struct scatterlist *sg; - - if (segment->data != NULL || !segment->sg) - return; - - sg = segment->sg; - BUG_ON(segment->sg_mapped); - BUG_ON(sg->length == 0); - - /* - * If the page count is greater than one it is ok to send - * to the network layer's zero copy send path. If not we - * have to go the slow sendmsg path. We always map for the - * recv path. - */ - if (page_count(sg_page(sg)) >= 1 && !recv) - return; - - debug_tcp("iscsi_tcp_segment_map %s %p\n", recv ? "recv" : "xmit", - segment); - segment->sg_mapped = kmap_atomic(sg_page(sg), KM_SOFTIRQ0); - segment->data = segment->sg_mapped + sg->offset + segment->sg_offset; -} - -static inline void -iscsi_tcp_segment_unmap(struct iscsi_segment *segment) -{ - debug_tcp("iscsi_tcp_segment_unmap %p\n", segment); - - if (segment->sg_mapped) { - debug_tcp("iscsi_tcp_segment_unmap valid\n"); - kunmap_atomic(segment->sg_mapped, KM_SOFTIRQ0); - segment->sg_mapped = NULL; - segment->data = NULL; - } -} - -/* - * Splice the digest buffer into the buffer - */ -static inline void -iscsi_tcp_segment_splice_digest(struct iscsi_segment *segment, void *digest) -{ - segment->data = digest; - segment->digest_len = ISCSI_DIGEST_SIZE; - segment->total_size += ISCSI_DIGEST_SIZE; - segment->size = ISCSI_DIGEST_SIZE; - segment->copied = 0; - segment->sg = NULL; - segment->hash = NULL; -} - -/** - * iscsi_tcp_segment_done - check whether the segment is complete - * @segment: iscsi segment to check - * @recv: set to one of this is called from the recv path - * @copied: number of bytes copied - * - * Check if we're done receiving this segment. If the receive - * buffer is full but we expect more data, move on to the - * next entry in the scatterlist. - * - * If the amount of data we received isn't a multiple of 4, - * we will transparently receive the pad bytes, too. - * - * This function must be re-entrant. - */ -static inline int -iscsi_tcp_segment_done(struct iscsi_segment *segment, int recv, unsigned copied) -{ - static unsigned char padbuf[ISCSI_PAD_LEN]; - struct scatterlist sg; - unsigned int pad; - - debug_tcp("copied %u %u size %u %s\n", segment->copied, copied, - segment->size, recv ? "recv" : "xmit"); - if (segment->hash && copied) { - /* - * If a segment is kmapd we must unmap it before sending - * to the crypto layer since that will try to kmap it again. - */ - iscsi_tcp_segment_unmap(segment); - - if (!segment->data) { - sg_init_table(&sg, 1); - sg_set_page(&sg, sg_page(segment->sg), copied, - segment->copied + segment->sg_offset + - segment->sg->offset); - } else - sg_init_one(&sg, segment->data + segment->copied, - copied); - crypto_hash_update(segment->hash, &sg, copied); - } - - segment->copied += copied; - if (segment->copied < segment->size) { - iscsi_tcp_segment_map(segment, recv); - return 0; - } - - segment->total_copied += segment->copied; - segment->copied = 0; - segment->size = 0; - - /* Unmap the current scatterlist page, if there is one. */ - iscsi_tcp_segment_unmap(segment); - - /* Do we have more scatterlist entries? */ - debug_tcp("total copied %u total size %u\n", segment->total_copied, - segment->total_size); - if (segment->total_copied < segment->total_size) { - /* Proceed to the next entry in the scatterlist. */ - iscsi_tcp_segment_init_sg(segment, sg_next(segment->sg), - 0); - iscsi_tcp_segment_map(segment, recv); - BUG_ON(segment->size == 0); - return 0; - } - - /* Do we need to handle padding? */ - pad = iscsi_padding(segment->total_copied); - if (pad != 0) { - debug_tcp("consume %d pad bytes\n", pad); - segment->total_size += pad; - segment->size = pad; - segment->data = padbuf; - return 0; - } - - /* - * Set us up for transferring the data digest. hdr digest - * is completely handled in hdr done function. - */ - if (segment->hash) { - crypto_hash_final(segment->hash, segment->digest); - iscsi_tcp_segment_splice_digest(segment, - recv ? segment->recv_digest : segment->digest); - return 0; - } - - return 1; -} - /** - * iscsi_tcp_xmit_segment - transmit segment - * @tcp_conn: the iSCSI TCP connection - * @segment: the buffer to transmnit - * - * This function transmits as much of the buffer as - * the network layer will accept, and returns the number of - * bytes transmitted. - * - * If CRC hashing is enabled, the function will compute the - * hash as it goes. When the entire segment has been transmitted, - * it will retrieve the hash value and send it as well. - */ -static int -iscsi_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn, - struct iscsi_segment *segment) -{ - struct socket *sk = tcp_conn->sock; - unsigned int copied = 0; - int r = 0; - - while (!iscsi_tcp_segment_done(segment, 0, r)) { - struct scatterlist *sg; - unsigned int offset, copy; - int flags = 0; - - r = 0; - offset = segment->copied; - copy = segment->size - offset; - - if (segment->total_copied + segment->size < segment->total_size) - flags |= MSG_MORE; - - /* Use sendpage if we can; else fall back to sendmsg */ - if (!segment->data) { - sg = segment->sg; - offset += segment->sg_offset + sg->offset; - r = tcp_conn->sendpage(sk, sg_page(sg), offset, copy, - flags); - } else { - struct msghdr msg = { .msg_flags = flags }; - struct kvec iov = { - .iov_base = segment->data + offset, - .iov_len = copy - }; - - r = kernel_sendmsg(sk, &msg, &iov, 1, copy); - } - - if (r < 0) { - iscsi_tcp_segment_unmap(segment); - if (copied || r == -EAGAIN) - break; - return r; - } - copied += r; - } - return copied; -} - -/** - * iscsi_tcp_segment_recv - copy data to segment - * @tcp_conn: the iSCSI TCP connection - * @segment: the buffer to copy to - * @ptr: data pointer - * @len: amount of data available - * - * This function copies up to @len bytes to the - * given buffer, and returns the number of bytes - * consumed, which can actually be less than @len. - * - * If hash digest is enabled, the function will update the - * hash while copying. - * Combining these two operations doesn't buy us a lot (yet), - * but in the future we could implement combined copy+crc, - * just way we do for network layer checksums. - */ -static int -iscsi_tcp_segment_recv(struct iscsi_tcp_conn *tcp_conn, - struct iscsi_segment *segment, const void *ptr, - unsigned int len) -{ - unsigned int copy = 0, copied = 0; - - while (!iscsi_tcp_segment_done(segment, 1, copy)) { - if (copied == len) { - debug_tcp("iscsi_tcp_segment_recv copied %d bytes\n", - len); - break; - } - - copy = min(len - copied, segment->size - segment->copied); - debug_tcp("iscsi_tcp_segment_recv copying %d\n", copy); - memcpy(segment->data + segment->copied, ptr + copied, copy); - copied += copy; - } - return copied; -} - -static inline void -iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr, size_t hdrlen, - unsigned char digest[ISCSI_DIGEST_SIZE]) -{ - struct scatterlist sg; - - sg_init_one(&sg, hdr, hdrlen); - crypto_hash_digest(hash, &sg, hdrlen, digest); -} - -static inline int -iscsi_tcp_dgst_verify(struct iscsi_tcp_conn *tcp_conn, - struct iscsi_segment *segment) -{ - if (!segment->digest_len) - return 1; - - if (memcmp(segment->recv_digest, segment->digest, - segment->digest_len)) { - debug_scsi("digest mismatch\n"); - return 0; - } - - return 1; -} - -/* - * Helper function to set up segment buffer - */ -static inline void -__iscsi_segment_init(struct iscsi_segment *segment, size_t size, - iscsi_segment_done_fn_t *done, struct hash_desc *hash) -{ - memset(segment, 0, sizeof(*segment)); - segment->total_size = size; - segment->done = done; - - if (hash) { - segment->hash = hash; - crypto_hash_init(hash); - } -} - -static inline void -iscsi_segment_init_linear(struct iscsi_segment *segment, void *data, - size_t size, iscsi_segment_done_fn_t *done, - struct hash_desc *hash) -{ - __iscsi_segment_init(segment, size, done, hash); - segment->data = data; - segment->size = size; -} - -static inline int -iscsi_segment_seek_sg(struct iscsi_segment *segment, - struct scatterlist *sg_list, unsigned int sg_count, - unsigned int offset, size_t size, - iscsi_segment_done_fn_t *done, struct hash_desc *hash) -{ - struct scatterlist *sg; - unsigned int i; - - debug_scsi("iscsi_segment_seek_sg offset %u size %llu\n", - offset, size); - __iscsi_segment_init(segment, size, done, hash); - for_each_sg(sg_list, sg, sg_count, i) { - debug_scsi("sg %d, len %u offset %u\n", i, sg->length, - sg->offset); - if (offset < sg->length) { - iscsi_tcp_segment_init_sg(segment, sg, offset); - return 0; - } - offset -= sg->length; - } - - return ISCSI_ERR_DATA_OFFSET; -} - -/** - * iscsi_tcp_hdr_recv_prep - prep segment for hdr reception - * @tcp_conn: iscsi connection to prep for - * - * This function always passes NULL for the hash argument, because when this - * function is called we do not yet know the final size of the header and want - * to delay the digest processing until we know that. - */ -static void -iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn) -{ - debug_tcp("iscsi_tcp_hdr_recv_prep(%p%s)\n", tcp_conn, - tcp_conn->iscsi_conn->hdrdgst_en ? ", digest enabled" : ""); - iscsi_segment_init_linear(&tcp_conn->in.segment, - tcp_conn->in.hdr_buf, sizeof(struct iscsi_hdr), - iscsi_tcp_hdr_recv_done, NULL); -} - -/* - * Handle incoming reply to any other type of command - */ -static int -iscsi_tcp_data_recv_done(struct iscsi_tcp_conn *tcp_conn, - struct iscsi_segment *segment) -{ - struct iscsi_conn *conn = tcp_conn->iscsi_conn; - int rc = 0; - - if (!iscsi_tcp_dgst_verify(tcp_conn, segment)) - return ISCSI_ERR_DATA_DGST; - - rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, - conn->data, tcp_conn->in.datalen); - if (rc) - return rc; - - iscsi_tcp_hdr_recv_prep(tcp_conn); - return 0; -} - -static void -iscsi_tcp_data_recv_prep(struct iscsi_tcp_conn *tcp_conn) -{ - struct iscsi_conn *conn = tcp_conn->iscsi_conn; - struct hash_desc *rx_hash = NULL; - - if (conn->datadgst_en & - !(conn->session->tt->caps & CAP_DIGEST_OFFLOAD)) - rx_hash = &tcp_conn->rx_hash; - - iscsi_segment_init_linear(&tcp_conn->in.segment, - conn->data, tcp_conn->in.datalen, - iscsi_tcp_data_recv_done, rx_hash); -} - -/* - * must be called with session lock - */ -static void iscsi_tcp_cleanup_task(struct iscsi_task *task) -{ - struct iscsi_tcp_task *tcp_task = task->dd_data; - struct iscsi_r2t_info *r2t; - - /* nothing to do for mgmt or pending tasks */ - if (!task->sc || task->state == ISCSI_TASK_PENDING) - return; - - /* flush task's r2t queues */ - while (__kfifo_get(tcp_task->r2tqueue, (void*)&r2t, sizeof(void*))) { - __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t, - sizeof(void*)); - debug_scsi("iscsi_tcp_cleanup_task pending r2t dropped\n"); - } - - r2t = tcp_task->r2t; - if (r2t != NULL) { - __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t, - sizeof(void*)); - tcp_task->r2t = NULL; - } -} - -/** - * iscsi_tcp_data_in - SCSI Data-In Response processing - * @conn: iscsi connection - * @task: scsi command task - */ -static int iscsi_tcp_data_in(struct iscsi_conn *conn, struct iscsi_task *task) -{ - struct iscsi_tcp_conn *tcp_conn = conn->dd_data; - struct iscsi_tcp_task *tcp_task = task->dd_data; - struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr; - int datasn = be32_to_cpu(rhdr->datasn); - unsigned total_in_length = scsi_in(task->sc)->length; - - iscsi_update_cmdsn(conn->session, (struct iscsi_nopin*)rhdr); - if (tcp_conn->in.datalen == 0) - return 0; - - if (tcp_task->exp_datasn != datasn) { - debug_tcp("%s: task->exp_datasn(%d) != rhdr->datasn(%d)\n", - __func__, tcp_task->exp_datasn, datasn); - return ISCSI_ERR_DATASN; - } - - tcp_task->exp_datasn++; - - tcp_task->data_offset = be32_to_cpu(rhdr->offset); - if (tcp_task->data_offset + tcp_conn->in.datalen > total_in_length) { - debug_tcp("%s: data_offset(%d) + data_len(%d) > total_length_in(%d)\n", - __func__, tcp_task->data_offset, - tcp_conn->in.datalen, total_in_length); - return ISCSI_ERR_DATA_OFFSET; - } - - conn->datain_pdus_cnt++; - return 0; -} - -/** - * iscsi_tcp_r2t_rsp - iSCSI R2T Response processing - * @conn: iscsi connection - * @task: scsi command task - */ -static int iscsi_tcp_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task) -{ - struct iscsi_session *session = conn->session; - struct iscsi_tcp_task *tcp_task = task->dd_data; - struct iscsi_tcp_conn *tcp_conn = conn->dd_data; - struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr; - struct iscsi_r2t_info *r2t; - int r2tsn = be32_to_cpu(rhdr->r2tsn); - int rc; - - if (tcp_conn->in.datalen) { - iscsi_conn_printk(KERN_ERR, conn, - "invalid R2t with datalen %d\n", - tcp_conn->in.datalen); - return ISCSI_ERR_DATALEN; - } - - if (tcp_task->exp_datasn != r2tsn){ - debug_tcp("%s: task->exp_datasn(%d) != rhdr->r2tsn(%d)\n", - __func__, tcp_task->exp_datasn, r2tsn); - return ISCSI_ERR_R2TSN; - } - - /* fill-in new R2T associated with the task */ - iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr); - - if (!task->sc || session->state != ISCSI_STATE_LOGGED_IN) { - iscsi_conn_printk(KERN_INFO, conn, - "dropping R2T itt %d in recovery.\n", - task->itt); - return 0; - } - - rc = __kfifo_get(tcp_task->r2tpool.queue, (void*)&r2t, sizeof(void*)); - if (!rc) { - iscsi_conn_printk(KERN_ERR, conn, "Could not allocate R2T. " - "Target has sent more R2Ts than it " - "negotiated for or driver has has leaked.\n"); - return ISCSI_ERR_PROTO; - } - - r2t->exp_statsn = rhdr->statsn; - r2t->data_length = be32_to_cpu(rhdr->data_length); - if (r2t->data_length == 0) { - iscsi_conn_printk(KERN_ERR, conn, - "invalid R2T with zero data len\n"); - __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t, - sizeof(void*)); - return ISCSI_ERR_DATALEN; - } - - if (r2t->data_length > session->max_burst) - debug_scsi("invalid R2T with data len %u and max burst %u." - "Attempting to execute request.\n", - r2t->data_length, session->max_burst); - - r2t->data_offset = be32_to_cpu(rhdr->data_offset); - if (r2t->data_offset + r2t->data_length > scsi_out(task->sc)->length) { - iscsi_conn_printk(KERN_ERR, conn, - "invalid R2T with data len %u at offset %u " - "and total length %d\n", r2t->data_length, - r2t->data_offset, scsi_out(task->sc)->length); - __kfifo_put(tcp_task->r2tpool.queue, (void*)&r2t, - sizeof(void*)); - return ISCSI_ERR_DATALEN; - } - - r2t->ttt = rhdr->ttt; /* no flip */ - r2t->datasn = 0; - r2t->sent = 0; - - tcp_task->exp_datasn = r2tsn + 1; - __kfifo_put(tcp_task->r2tqueue, (void*)&r2t, sizeof(void*)); - conn->r2t_pdus_cnt++; - - iscsi_requeue_task(task); - return 0; -} - -/* - * Handle incoming reply to DataIn command - */ -static int -iscsi_tcp_process_data_in(struct iscsi_tcp_conn *tcp_conn, - struct iscsi_segment *segment) -{ - struct iscsi_conn *conn = tcp_conn->iscsi_conn; - struct iscsi_hdr *hdr = tcp_conn->in.hdr; - int rc; - - if (!iscsi_tcp_dgst_verify(tcp_conn, segment)) - return ISCSI_ERR_DATA_DGST; - - /* check for non-exceptional status */ - if (hdr->flags & ISCSI_FLAG_DATA_STATUS) { - rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0); - if (rc) - return rc; - } - - iscsi_tcp_hdr_recv_prep(tcp_conn); - return 0; -} - -/** - * iscsi_tcp_hdr_dissect - process PDU header - * @conn: iSCSI connection - * @hdr: PDU header - * - * This function analyzes the header of the PDU received, - * and performs several sanity checks. If the PDU is accompanied - * by data, the receive buffer is set up to copy the incoming data - * to the correct location. - */ -static int -iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr) -{ - int rc = 0, opcode, ahslen; - struct iscsi_tcp_conn *tcp_conn = conn->dd_data; - struct iscsi_task *task; - - /* verify PDU length */ - tcp_conn->in.datalen = ntoh24(hdr->dlength); - if (tcp_conn->in.datalen > conn->max_recv_dlength) { - iscsi_conn_printk(KERN_ERR, conn, - "iscsi_tcp: datalen %d > %d\n", - tcp_conn->in.datalen, conn->max_recv_dlength); - return ISCSI_ERR_DATALEN; - } - - /* Additional header segments. So far, we don't - * process additional headers. - */ - ahslen = hdr->hlength << 2; - - opcode = hdr->opcode & ISCSI_OPCODE_MASK; - /* verify itt (itt encoding: age+cid+itt) */ - rc = iscsi_verify_itt(conn, hdr->itt); - if (rc) - return rc; - - debug_tcp("opcode 0x%x ahslen %d datalen %d\n", - opcode, ahslen, tcp_conn->in.datalen); - - switch(opcode) { - case ISCSI_OP_SCSI_DATA_IN: - spin_lock(&conn->session->lock); - task = iscsi_itt_to_ctask(conn, hdr->itt); - if (!task) - rc = ISCSI_ERR_BAD_ITT; - else - rc = iscsi_tcp_data_in(conn, task); - if (rc) { - spin_unlock(&conn->session->lock); - break; - } - - if (tcp_conn->in.datalen) { - struct iscsi_tcp_task *tcp_task = task->dd_data; - struct hash_desc *rx_hash = NULL; - struct scsi_data_buffer *sdb = scsi_in(task->sc); - - /* - * Setup copy of Data-In into the Scsi_Cmnd - * Scatterlist case: - * We set up the iscsi_segment to point to the next - * scatterlist entry to copy to. As we go along, - * we move on to the next scatterlist entry and - * update the digest per-entry. - */ - if (conn->datadgst_en && - !(conn->session->tt->caps & CAP_DIGEST_OFFLOAD)) - rx_hash = &tcp_conn->rx_hash; - - debug_tcp("iscsi_tcp_begin_data_in(%p, offset=%d, " - "datalen=%d)\n", tcp_conn, - tcp_task->data_offset, - tcp_conn->in.datalen); - rc = iscsi_segment_seek_sg(&tcp_conn->in.segment, - sdb->table.sgl, - sdb->table.nents, - tcp_task->data_offset, - tcp_conn->in.datalen, - iscsi_tcp_process_data_in, - rx_hash); - spin_unlock(&conn->session->lock); - return rc; - } - rc = __iscsi_complete_pdu(conn, hdr, NULL, 0); - spin_unlock(&conn->session->lock); - break; - case ISCSI_OP_SCSI_CMD_RSP: - if (tcp_conn->in.datalen) { - iscsi_tcp_data_recv_prep(tcp_conn); - return 0; - } - rc = iscsi_complete_pdu(conn, hdr, NULL, 0); - break; - case ISCSI_OP_R2T: - spin_lock(&conn->session->lock); - task = iscsi_itt_to_ctask(conn, hdr->itt); - if (!task) - rc = ISCSI_ERR_BAD_ITT; - else if (ahslen) - rc = ISCSI_ERR_AHSLEN; - else if (task->sc->sc_data_direction == DMA_TO_DEVICE) - rc = iscsi_tcp_r2t_rsp(conn, task); - else - rc = ISCSI_ERR_PROTO; - spin_unlock(&conn->session->lock); - break; - case ISCSI_OP_LOGIN_RSP: - case ISCSI_OP_TEXT_RSP: - case ISCSI_OP_REJECT: - case ISCSI_OP_ASYNC_EVENT: - /* - * It is possible that we could get a PDU with a buffer larger - * than 8K, but there are no targets that currently do this. - * For now we fail until we find a vendor that needs it - */ - if (ISCSI_DEF_MAX_RECV_SEG_LEN < tcp_conn->in.datalen) { - iscsi_conn_printk(KERN_ERR, conn, - "iscsi_tcp: received buffer of " - "len %u but conn buffer is only %u " - "(opcode %0x)\n", - tcp_conn->in.datalen, - ISCSI_DEF_MAX_RECV_SEG_LEN, opcode); - rc = ISCSI_ERR_PROTO; - break; - } - - /* If there's data coming in with the response, - * receive it to the connection's buffer. - */ - if (tcp_conn->in.datalen) { - iscsi_tcp_data_recv_prep(tcp_conn); - return 0; - } - /* fall through */ - case ISCSI_OP_LOGOUT_RSP: - case ISCSI_OP_NOOP_IN: - case ISCSI_OP_SCSI_TMFUNC_RSP: - rc = iscsi_complete_pdu(conn, hdr, NULL, 0); - break; - default: - rc = ISCSI_ERR_BAD_OPCODE; - break; - } - - if (rc == 0) { - /* Anything that comes with data should have - * been handled above. */ - if (tcp_conn->in.datalen) - return ISCSI_ERR_PROTO; - iscsi_tcp_hdr_recv_prep(tcp_conn); - } - - return rc; -} - -/** - * iscsi_tcp_hdr_recv_done - process PDU header - * - * This is the callback invoked when the PDU header has - * been received. If the header is followed by additional - * header segments, we go back for more data. - */ -static int -iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn, - struct iscsi_segment *segment) -{ - struct iscsi_conn *conn = tcp_conn->iscsi_conn; - struct iscsi_hdr *hdr; - - /* Check if there are additional header segments - * *prior* to computing the digest, because we - * may need to go back to the caller for more. - */ - hdr = (struct iscsi_hdr *) tcp_conn->in.hdr_buf; - if (segment->copied == sizeof(struct iscsi_hdr) && hdr->hlength) { - /* Bump the header length - the caller will - * just loop around and get the AHS for us, and - * call again. */ - unsigned int ahslen = hdr->hlength << 2; - - /* Make sure we don't overflow */ - if (sizeof(*hdr) + ahslen > sizeof(tcp_conn->in.hdr_buf)) - return ISCSI_ERR_AHSLEN; - - segment->total_size += ahslen; - segment->size += ahslen; - return 0; - } - - /* We're done processing the header. See if we're doing - * header digests; if so, set up the recv_digest buffer - * and go back for more. */ - if (conn->hdrdgst_en) { - if (segment->digest_len == 0) { - /* - * Even if we offload the digest processing we - * splice it in so we can increment the skb/segment - * counters in preparation for the data segment. - */ - iscsi_tcp_segment_splice_digest(segment, - segment->recv_digest); - return 0; - } - - if (!(conn->session->tt->caps & CAP_DIGEST_OFFLOAD)) { - iscsi_tcp_dgst_header(&tcp_conn->rx_hash, hdr, - segment->total_copied - ISCSI_DIGEST_SIZE, - segment->digest); - - if (!iscsi_tcp_dgst_verify(tcp_conn, segment)) - return ISCSI_ERR_HDR_DGST; - } - } - - tcp_conn->in.hdr = hdr; - return iscsi_tcp_hdr_dissect(conn, hdr); -} - -inline int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn) -{ - return tcp_conn->in.segment.done == iscsi_tcp_hdr_recv_done; -} - -enum { - ISCSI_TCP_SEGMENT_DONE, /* curr seg has been processed */ - ISCSI_TCP_SKB_DONE, /* skb is out of data */ - ISCSI_TCP_CONN_ERR, /* iscsi layer has fired a conn err */ - ISCSI_TCP_SUSPENDED, /* conn is suspended */ -}; - -/** - * iscsi_tcp_recv_skb - Process skb - * @conn: iscsi connection - * @skb: network buffer with header and/or data segment - * @offset: offset in skb - * @offload: bool indicating if transfer was offloaded - */ -int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb, - unsigned int offset, bool offloaded, int *status) -{ - struct iscsi_tcp_conn *tcp_conn = conn->dd_data; - struct iscsi_segment *segment = &tcp_conn->in.segment; - struct skb_seq_state seq; - unsigned int consumed = 0; - int rc = 0; - - debug_tcp("in %d bytes\n", skb->len - offset); - - if (unlikely(conn->suspend_rx)) { - debug_tcp("conn %d Rx suspended!\n", conn->id); - *status = ISCSI_TCP_SUSPENDED; - return 0; - } - - if (offloaded) { - segment->total_copied = segment->total_size; - goto segment_done; - } - - skb_prepare_seq_read(skb, offset, skb->len, &seq); - while (1) { - unsigned int avail; - const u8 *ptr; - - avail = skb_seq_read(consumed, &ptr, &seq); - if (avail == 0) { - debug_tcp("no more data avail. Consumed %d\n", - consumed); - *status = ISCSI_TCP_SKB_DONE; - skb_abort_seq_read(&seq); - goto skb_done; - } - BUG_ON(segment->copied >= segment->size); - - debug_tcp("skb %p ptr=%p avail=%u\n", skb, ptr, avail); - rc = iscsi_tcp_segment_recv(tcp_conn, segment, ptr, avail); - BUG_ON(rc == 0); - consumed += rc; - - if (segment->total_copied >= segment->total_size) { - skb_abort_seq_read(&seq); - goto segment_done; - } - } - -segment_done: - *status = ISCSI_TCP_SEGMENT_DONE; - debug_tcp("segment done\n"); - rc = segment->done(tcp_conn, segment); - if (rc != 0) { - *status = ISCSI_TCP_CONN_ERR; - debug_tcp("Error receiving PDU, errno=%d\n", rc); - iscsi_conn_failure(conn, rc); - return 0; - } - /* The done() functions sets up the next segment. */ - -skb_done: - conn->rxdata_octets += consumed; - return consumed; -} -EXPORT_SYMBOL_GPL(iscsi_tcp_recv_skb); - -/** - * iscsi_tcp_recv - TCP receive in sendfile fashion + * iscsi_sw_tcp_recv - TCP receive in sendfile fashion * @rd_desc: read descriptor * @skb: socket buffer * @offset: offset in skb * @len: skb->len - offset - **/ -static int -iscsi_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, - unsigned int offset, size_t len) + */ +static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, + unsigned int offset, size_t len) { struct iscsi_conn *conn = rd_desc->arg.data; unsigned int consumed, total_consumed = 0; @@ -993,8 +90,7 @@ iscsi_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, return total_consumed; } -static void -iscsi_tcp_data_ready(struct sock *sk, int flag) +static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag) { struct iscsi_conn *conn = sk->sk_user_data; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; @@ -1010,7 +106,7 @@ iscsi_tcp_data_ready(struct sock *sk, int flag) */ rd_desc.arg.data = conn; rd_desc.count = 1; - tcp_read_sock(sk, &rd_desc, iscsi_tcp_recv); + tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv); read_unlock(&sk->sk_callback_lock); @@ -1019,10 +115,10 @@ iscsi_tcp_data_ready(struct sock *sk, int flag) iscsi_tcp_segment_unmap(&tcp_conn->in.segment); } -static void -iscsi_tcp_state_change(struct sock *sk) +static void iscsi_sw_tcp_state_change(struct sock *sk) { struct iscsi_tcp_conn *tcp_conn; + struct iscsi_sw_tcp_conn *tcp_sw_conn; struct iscsi_conn *conn; struct iscsi_session *session; void (*old_state_change)(struct sock *); @@ -1040,7 +136,8 @@ iscsi_tcp_state_change(struct sock *sk) } tcp_conn = conn->dd_data; - old_state_change = tcp_conn->old_state_change; + tcp_sw_conn = tcp_conn->dd_data; + old_state_change = tcp_sw_conn->old_state_change; read_unlock(&sk->sk_callback_lock); @@ -1051,59 +148,122 @@ iscsi_tcp_state_change(struct sock *sk) * iscsi_write_space - Called when more output buffer space is available * @sk: socket space is available for **/ -static void iscsi_tcp_write_space(struct sock *sk) +static void iscsi_sw_tcp_write_space(struct sock *sk) { struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; - tcp_conn->old_write_space(sk); + tcp_sw_conn->old_write_space(sk); debug_tcp("iscsi_write_space: cid %d\n", conn->id); scsi_queue_work(conn->session->host, &conn->xmitwork); } -static void iscsi_tcp_conn_set_callbacks(struct iscsi_conn *conn) +static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn) { struct iscsi_tcp_conn *tcp_conn = conn->dd_data; - struct sock *sk = tcp_conn->sock->sk; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct sock *sk = tcp_sw_conn->sock->sk; /* assign new callbacks */ write_lock_bh(&sk->sk_callback_lock); sk->sk_user_data = conn; - tcp_conn->old_data_ready = sk->sk_data_ready; - tcp_conn->old_state_change = sk->sk_state_change; - tcp_conn->old_write_space = sk->sk_write_space; - sk->sk_data_ready = iscsi_tcp_data_ready; - sk->sk_state_change = iscsi_tcp_state_change; - sk->sk_write_space = iscsi_tcp_write_space; + tcp_sw_conn->old_data_ready = sk->sk_data_ready; + tcp_sw_conn->old_state_change = sk->sk_state_change; + tcp_sw_conn->old_write_space = sk->sk_write_space; + sk->sk_data_ready = iscsi_sw_tcp_data_ready; + sk->sk_state_change = iscsi_sw_tcp_state_change; + sk->sk_write_space = iscsi_sw_tcp_write_space; write_unlock_bh(&sk->sk_callback_lock); } -static void iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn) +static void +iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_sw_tcp_conn *tcp_sw_conn) { - struct sock *sk = tcp_conn->sock->sk; + struct sock *sk = tcp_sw_conn->sock->sk; /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */ write_lock_bh(&sk->sk_callback_lock); sk->sk_user_data = NULL; - sk->sk_data_ready = tcp_conn->old_data_ready; - sk->sk_state_change = tcp_conn->old_state_change; - sk->sk_write_space = tcp_conn->old_write_space; + sk->sk_data_ready = tcp_sw_conn->old_data_ready; + sk->sk_state_change = tcp_sw_conn->old_state_change; + sk->sk_write_space = tcp_sw_conn->old_write_space; sk->sk_no_check = 0; write_unlock_bh(&sk->sk_callback_lock); } /** - * iscsi_tcp_xmit - TCP transmit + * iscsi_sw_tcp_xmit_segment - transmit segment + * @tcp_sw_conn: the iSCSI TCP connection + * @segment: the buffer to transmnit + * + * This function transmits as much of the buffer as + * the network layer will accept, and returns the number of + * bytes transmitted. + * + * If CRC hashing is enabled, the function will compute the + * hash as it goes. When the entire segment has been transmitted, + * it will retrieve the hash value and send it as well. + */ +static int iscsi_sw_tcp_xmit_segment(struct iscsi_sw_tcp_conn *tcp_sw_conn, + struct iscsi_segment *segment) +{ + struct socket *sk = tcp_sw_conn->sock; + unsigned int copied = 0; + int r = 0; + + while (!iscsi_tcp_segment_done(segment, 0, r)) { + struct scatterlist *sg; + unsigned int offset, copy; + int flags = 0; + + r = 0; + offset = segment->copied; + copy = segment->size - offset; + + if (segment->total_copied + segment->size < segment->total_size) + flags |= MSG_MORE; + + /* Use sendpage if we can; else fall back to sendmsg */ + if (!segment->data) { + sg = segment->sg; + offset += segment->sg_offset + sg->offset; + r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset, + copy, flags); + } else { + struct msghdr msg = { .msg_flags = flags }; + struct kvec iov = { + .iov_base = segment->data + offset, + .iov_len = copy + }; + + r = kernel_sendmsg(sk, &msg, &iov, 1, copy); + } + + if (r < 0) { + iscsi_tcp_segment_unmap(segment); + if (copied || r == -EAGAIN) + break; + return r; + } + copied += r; + } + retur |