diff options
author | Boaz Harrosh <bharrosh@panasas.com> | 2007-12-13 12:43:23 -0600 |
---|---|---|
committer | James Bottomley <James.Bottomley@HansenPartnership.com> | 2008-01-11 18:28:23 -0600 |
commit | 004d6530f83bee43a55b51bb5960db96e7ae0ffa (patch) | |
tree | a7bb6ffb3e6e89ca6ee9b164d5f19899a0c100dd /include/scsi/libiscsi.h | |
parent | 7207fea452cfdd2d4e2f4419e2c31f570edbade3 (diff) |
[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>
Diffstat (limited to 'include/scsi/libiscsi.h')
-rw-r--r-- | include/scsi/libiscsi.h | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h index e1fb3d0927b..a9a9e869188 100644 --- a/include/scsi/libiscsi.h +++ b/include/scsi/libiscsi.h @@ -78,6 +78,9 @@ enum { #define ISCSI_ADDRESS_BUF_LEN 64 enum { + /* this is the maximum possible storage for AHSs */ + ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) + + sizeof(struct iscsi_rlength_ahdr), ISCSI_DIGEST_SIZE = sizeof(__u32), }; @@ -102,10 +105,13 @@ enum { struct iscsi_cmd_task { /* - * Becuae LLDs allocate their hdr differently, this is a pointer to - * that storage. It must be setup at session creation time. + * Because LLDs allocate their hdr differently, this is a pointer + * and length to that storage. It must be setup at session + * creation time. */ struct iscsi_cmd *hdr; + unsigned short hdr_max; + unsigned short hdr_len; /* accumulated size of hdr used */ int itt; /* this ITT */ uint32_t unsol_datasn; @@ -124,6 +130,11 @@ struct iscsi_cmd_task { void *dd_data; /* driver/transport data */ }; +static inline void* iscsi_next_hdr(struct iscsi_cmd_task *ctask) +{ + return (void*)ctask->hdr + ctask->hdr_len; +} + struct iscsi_conn { struct iscsi_cls_conn *cls_conn; /* ptr to class connection */ void *dd_data; /* iscsi_transport data */ @@ -342,4 +353,22 @@ extern void iscsi_requeue_ctask(struct iscsi_cmd_task *ctask); extern void iscsi_pool_free(struct iscsi_queue *, void **); extern int iscsi_pool_init(struct iscsi_queue *, int, void ***, int); +/* + * inline functions to deal with padding. + */ +static inline unsigned int +iscsi_padded(unsigned int len) +{ + return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1); +} + +static inline unsigned int +iscsi_padding(unsigned int len) +{ + len &= (ISCSI_PAD_LEN - 1); + if (len) + len = ISCSI_PAD_LEN - len; + return len; +} + #endif |