[SCSI] iscsi_tcp, libiscsi: initial AHS Support
at libiscsi generic code
- currently code assumes a storage space of pdu header is allocated
at llds ctask and is pointed to by iscsi_cmd_task->hdr. Here I add
a hdr_max field pertaining to that storage, and an hdr_len that
accumulates the current use of the pdu-header.
- Add an iscsi_next_hdr() inline which returns the next free space
to write new Header at. Also iscsi_next_hdr() is used to retrieve
the address at which to write the header-digest.
- Add iscsi_add_hdr(length). What the user do is calls iscsi_next_hdr()
for address of the new header, than calls iscsi_add_hdr(length) with
the size of the new header. iscsi_add_hdr() will check if space is
available and update to the new size. length must be padded according
to standard.
- Add 2 padding inline helpers thanks to Olaf. Current patch does not
use them but Following patches will.
Also moved definition of ISCSI_PAD_LEN to iscsi_proto.h which had
PAD_WORD_LEN that was never used anywhere.
- Let iscsi_prep_scsi_cmd_pdu() signal an Error return since now it is
possible that it will fail.
- I was tired of yet again writing a "this is a digest" comment next to
sizeof(__u32) so I defined a new ISCSI_DIGEST_SIZE. Now I don't need
any comments. Changed all places that used sizeof(__u32) or "4" in
connection to a digest.
iscsi_tcp specific code
- At struct iscsi_tcp_cmd_task allocate maximum space allowed in
standard for all headers following the iscsi_cmd header. and mark
it so in iscsi_tcp_session_create()
- At iscsi_send_cmd_hdr() retrieve the correct headers size and
write header digest at iscsi_next_hdr().
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index fd88777..491845f 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -113,7 +113,7 @@
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
crypto_hash_digest(&tcp_conn->tx_hash, &buf->sg, buf->sg.length, crc);
- buf->sg.length += sizeof(u32);
+ buf->sg.length += ISCSI_DIGEST_SIZE;
}
/*
@@ -220,6 +220,7 @@
iscsi_tcp_chunk_done(struct iscsi_chunk *chunk)
{
static unsigned char padbuf[ISCSI_PAD_LEN];
+ unsigned int pad;
if (chunk->copied < chunk->size) {
iscsi_tcp_chunk_map(chunk);
@@ -243,10 +244,8 @@
}
/* Do we need to handle padding? */
- if (chunk->total_copied & (ISCSI_PAD_LEN-1)) {
- unsigned int pad;
-
- pad = ISCSI_PAD_LEN - (chunk->total_copied & (ISCSI_PAD_LEN-1));
+ pad = iscsi_padding(chunk->total_copied);
+ if (pad != 0) {
debug_tcp("consume %d pad bytes\n", pad);
chunk->total_size += pad;
chunk->size = pad;
@@ -1385,11 +1384,11 @@
}
iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
- sizeof(struct iscsi_hdr));
+ ctask->hdr_len);
if (conn->hdrdgst_en)
iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
- (u8*)tcp_ctask->hdrext);
+ iscsi_next_hdr(ctask));
tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_INIT;
tcp_ctask->xmstate |= XMSTATE_CMD_HDR_XMIT;
}
@@ -2176,7 +2175,8 @@
struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
- ctask->hdr = &tcp_ctask->hdr;
+ ctask->hdr = &tcp_ctask->hdr.cmd_hdr;
+ ctask->hdr_max = sizeof(tcp_ctask->hdr) - ISCSI_DIGEST_SIZE;
}
for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
