aboutsummaryrefslogtreecommitdiff
path: root/drivers/scsi/iscsi_tcp.c
AgeCommit message (Collapse)Author
2009-06-21iscsi_tcp: propogate EAGAIN from sendpage to libiscsiMike Christie
The net layer might return -EAGAIN because it could not get space/mem within the sock sndtimeo or becuase the tcp/ip connection was down. For the latter we do not want to retry because the conn/session should just be shutdown and restarted. libiscsi knows the state of the session recovery so propogate this error to that layer. It will either do iscsi recovery or have us retry the operation. Right now if we have partially sent a pdu we would always retry the IO xmit slowing down recovery. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-04-27[SCSI] cxgb3i, iser, iscsi_tcp: set target can queueMike Christie
Set target can queue limit to the number of preallocated session tasks we have. This along with the cxgb3i can_queue patch will fix a throughput problem where it could only queue one LU worth of data at a time. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-04-27[SCSI] iscsi_tcp: don't fire conn error if pdu init failsMike Christie
If a command's scsi cmd pdu setup fails then we can just fail the IO to the scsi layer. If a DATA_OUT for a R2T fails then we will want to drop the session, because it means we got a bad request from the target (iscsi protocol error). This patch has us propogate the error upwards so libiscsi_tcp or libiscsi can decide what the best action is to take. It also fixes a bug where we could try to grab the session lock while holding it, because if iscsi_tcp drops the session in the pdu setup callout the session lock is held when setting up the scsi cmd pdu. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-13[SCSI] iscsi class: remove host no argument from session creation calloutMike Christie
We do not need to have llds set the host no for the session's parent, because we know the session's parent is going to be the host. This removes it from the session creation callback and converts the drivers. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-13[SCSI] iscsi lib: remove qdepth param from iscsi host allocationMike Christie
The qdepth setting was useful when we needed libiscsi to verify the setting. Now we just need to make sure if older tools passed in zero then we need to set some default. So this patch just has us use the sht->cmd_per_lun or if for LLD does a host per session then we can set it on per host basis. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-13[SCSI] iscsi lib: have lib create work queue for transmitting IOMike Christie
We were using the shost work queue which ended up being a little akward since all iscsi hosts need a thread for scanning, but only drivers hooked into libiscsi need a workqueue for transmitting. So this patch moves the xmit workqueue to the lib. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-13[SCSI] iscsi_tcp: replace scsi_debug/tcp_debug logging with iscsi conn loggingMike Christie
This makes the logging a compile time option and replaces the tcp_debug macro with a iscsi connection one that prints out a driver model id prefix. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-13[SCSI] iscsi tcp: bidi capablePete Wyckoff
Mark iscsi_tcp as being capable of bidirectional transfers. The bsg interface checks this bit before attempting any bidirectional commands. Signed-off-by: Pete Wyckoff <pw@padd.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-29[SCSI] libiscsi_tcp: support padding offloadMike Christie
cxgb3i does not offload the processing of the header, but it will always process the padding. This patch adds a padding offload flag to detect when the LLD supports this. The patch also modifies the header processing so that we do not try to read/bypass the header dugest in the skb. cxgb3i will not include it with the header like with other offload cards. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-29[SCSI] libiscsi: pass opcode into alloc_pdu calloutMike Christie
We do not need to allocate a itt for data_out, so this passes the opcode to the alloc_pdu callout. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-29[SCSI] iscsi_tcp: hook iscsi_tcp into new libiscsi_tcp moduleMike Christie
This hooks iscsi_tcp into the libiscsi_tcp module and removes code that is now in libiscsi_tcp. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-29[SCSI] iscsi_tcp: add iscsi_tcp prefix to iscsi_tcp functionsMike Christie
Add iscsi_tcp prefix to most functions. Some are not changed becuase they are going to move in the next patch. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-29[SCSI] iscsi_tcp: remove unused r2t handlingMike Christie
libiscsi's iscsi_prep_data_out_pdu now handles what iscsi_tcp's helpers were so we can remove iscsi_tcp's helpers. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-29[SCSI] iscsi_tcp: convert to new alloc_hdr apiMike Christie
This converts iscsi_tcp to the new api and modifies how it handles r2ts. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-29[SCSI] iscsi_tcp: prepare helpers for LLDs that can offload some operationsMike Christie
cxgb3i is unlike qla4xxx and bnx2i in that it does not offload entire scsi commands or iscsi sequences. Instead it only offloads the transfer of a ISCSI DATA_IN pdu's data, the digests and padding. This patch fixes up the iscsi tcp recv path so that it exports its skb recv processing so cxgb3i and other drivers can call them. All they have to do is pass the function the skb with the hdr or data pdu header and this function will do the rest. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-31drivers: replace NIPQUAD()Harvey Harrison
Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u can be replaced with %pI4 Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29net: replace %p6 with %pI6Harvey Harrison
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-28misc: replace NIP6_FMT with %p6 format specifierHarvey Harrison
The iscsi_ibft.c changes are almost certainly a bugfix as the pointer 'ip' is a u8 *, so they never print the last 8 bytes of the IPv6 address, and the eight bytes they do print have a zero byte with them in each 16-bit word. Other than that, this should cause no difference in functionality. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-13[SCSI] iscsi_tcp: return a descriptive error value during connection errorsMike Christie
The segment->done functions return a iscsi error value which gives a lot more info than conn failed, so this patch has us return that value. I also add a new one for xmit failures. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-13[SCSI] libiscsi: rename host reset to target resetMike Christie
I had this in my patchset to add target reset support, but it got dropped due to patching conflicts. This initial patch just renames the function and users. We are actually just dropping the session, and so this does not have anything to do with the host exactly. It does for software iscsi because we allocate a host per session, but for cxgb3i this makes no sense. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-13[SCSI] libiscsi: Support drivers initiating session removalMike Christie
If the driver knows when hardware is removed like with cxgb3i, bnx2i, qla4xxx and iser then we will want to remove the sessions/devices that are bound to that device before removing the host. cxgb3i and in the future bnx2i will remove the host and that will remove all the sessions on the hba. iser can call iscsi_kill_session when it gets an event that indicates that a hca is removed. And when qla4xxx is hooked in to the lib (it is only hooked into the class right now) it can call iscsi remove host like the partial offload card drivers. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-13[SCSI] libiscsi: fix data corruption when target has to resend data-in packetsMike Christie
iscsi_tcp was updating the exp_statsn (exp_statsn acknowledges status and tells the target it is ok to let the resources for a iscsi pdu to be reused) before it got all the data for pdu read into OS buffers. Data corruption was occuring if something happens to a packet and the network layer requests a retransmit, and the initiator has told the target about the udpated exp_statsn ack, then the target may be sending data from a buffer it has reused for a new iscsi pdu. This fixes the problem by having the LLD (iscsi_tcp in this case) just handle the transferring of data, and has libiscsi handle the processing of status (libiscsi completion processing is done after LLD data transfers are complete). Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] libiscsi, iscsi_tcp, ib_iser: fix setting of can_queue with old tools.Mike Christie
This patch fixes two bugs that are related. 1. Old tools did not set can_queue/cmds_max. This patch modifies libiscsi so that when we add the host we catch this and set it to the default. 2. iscsi_tcp thought that the scsi command that was passed to the eh functions needed a iscsi_cmd_task allocated for it. It only needed a mgmt task, and now it does not matter since it all comes from the same pool and libiscsi handles this for the drivers. ib_iser had copied iscsi_tcp's code and set can_queue to its max - 1 to handle this. So this patch removes the max -1, and just sets it to the max. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] iscsi_tcp: Enable any size commandBoaz Harrosh
Let through upto the largest command of 260 defined by the scsi standard. iscsi core supports this already. Now that the scsi-ml supports it we can start using large commands. [jejb:rejections fixed up] Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Acked-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] Replace __FUNCTION__ with __func__ in iscsi_tcp.Harvey Harrison
__FUNCTION__ is gcc-specific, use __func__ (Update diff by Mike Christie) Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] libiscsi, iser, tcp: remove recv_lockMike Christie
The recv lock was defined so the iscsi layer could block the recv path from processing IO during recovery. It turns out iser just set a lock to that pointer which was pointless. We now disconnect the transport connection before doing recovery so we do not need the recv lock. For iscsi_tcp we still stop the recv path incase older tools are being used. This patch also has iscsi_itt_to_ctask user grab the session lock and has the caller access the task with the lock or get a ref to it in case the target is broken and sends a tmf success response then sends data or a response for the command that was supposed to be affected bty the tmf. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] iscsi class: Add session initiatorname and ifacename sysfs attrs.Mike Christie
This adds two new attrs used for creating initiator ports and binding sessions to hardware. The session level initiatorname: Since bnx2i does a scsi_host per host device, we need to add the iface initiator port settings on the session, so we can create multiple initiator ports (each with different inames) per device/scsi_host. The current iname reflects that qla4xxx can have one iname per hba, and we are allocating a host per session for software. The iname on the host will remain so we can export and set the hba level qla4xxx setting. The ifacename attr: To bind a session to a some peice of hardware in userspace we maintain some mappings, but during boot or iscsid restart (iscsid contains the user space part of the driver) we need to be able to figure out which of those host mappings abstractions maps to certain sessions. This patch adds a ifacename attr, which userspace can set to id the host side of the endpoint across pivot_roots and iscsid restarts. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] iscsi_tcp: hook iscsi_tcp into iscsi_endpoint codeMike Christie
iscsi_tcp creates its ep in userspace using sockets because it is virtual, so we just check if we are sent a ep and fail if we are. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] iscsi class: user device_for_each_child instead of duplicating ↵Mike Christie
session list Currently we duplicate the list of sessions, because we were using the test for if a session was on the host list to indicate if the session was bound or unbound. We can instead use the target_id and fix up the class so that drivers like bnx2i do not have to manage the target id space. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] iscsi_tcp: handle iscsi_cmd_task renameMike Christie
This converts iscsi_tcp to use the iscsi_task name. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] iscsi_tcp: convert iscsi_tcp to support merged tasksMike Christie
Convert iscsi_tcp to support merged tasks. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] libiscsi, iscsi_tcp, iser: add session cmds array accessorMike Christie
Currently to get a ctask from the session cmd array, you have to know to use the itt modifier. To make this easier on LLDs and so in the future we can easilly kill the session array and use the host shared map instead, this patch adds a nice wrapper to strip the itt into a session->cmds index and return a ctask. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] iscsi: remove session/conn_data_size from iscsi_transportMike Christie
This removes the session and conn data_size fields from the iscsi_transport. Just pass in the value like with host allocation. This patch also makes it so the LLD iscsi_conn data is allocated with the iscsi_cls_conn. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] iscsi: add iscsi host helpersMike Christie
This finishes the host/session unbinding, by adding some helpers to add and remove hosts and the session they manage. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] iscsi: remove session and host binding in libiscsiMike Christie
bnx2i allocates a host per netdevice but will use libiscsi, so this unbinds the session from the host in that code. This will also be useful for the iser parent device dma settings fixes. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] iscsi class, iscsi drivers: remove unused iscsi_transport attrsMike Christie
max_cmd_len and max_conn are not really used. max_cmd_len is always 16 and can be set by the LLD. max_conn is always one since we do not support MCS. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12[SCSI] iscsi class, iscsi_tcp/iser: add host arg to session creationMike Christie
iscsi offload (bnx2i and qla4xx) allocate a scsi host per hba, so the session creation path needs a shost/host_no argument. Software iscsi/iser will follow the same behabior as before where it allcoates a host per session, but in the future iser will probably look more like bnx2i where the host's parent is the hardware (rnic for iser and for bnx2i it is the nic), because it does not use a socket layer like how iscsi_tcp does. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-04-18[SCSI] iscsi: bidi support for iscsi_tcpBoaz Harrosh
access the right scsi_in() and/or scsi_out() side of things. also for resid Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Reviewed-by: Pete Wyckoff <pw@osc.edu> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-02-07[SCSI] iscsi: fix up iscsi printk prefixMike Christie
Some iscsi class messages have the dev_printk prefix and some libiscsi and iscsi_tcp messages have "iscsi" or the module name as a prefix which is normally pretty useless when trying to figure out which session or connection the message is attached to. This patch adds iscsi lib and class dev_printks so all messages have a common prefix that can be used to figure out which object printed it. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-01-30[SCSI] remove use_sg_chainingJames Bottomley
With the sg table code, every SCSI driver is now either chain capable or broken (or has sg_tablesize set so chaining is never activated), so there's no need to have a check in the host template. Also tidy up the code by moving the scatterlist size defines into the SCSI includes and permit the last entry of the scatterlist pools not to be a power of two. Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-01-11[SCSI] iscsi_tcp: fix setting of r2tMike Christie
If we negotiate for X r2ts we have to use only X r2ts. We cannot round up (we could send less though). It is ok to fail if it is not something the driver can handle, so this patch just does that. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-01-11[SCSI] iscsi_tcp: hold lock during data rsp processingMike Christie
iscsi_data_rsp needs to hold the sesison lock when it calls iscsi_update_cmdsn. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-01-11[SCSI] iscsi_tcp: enable sg chainingMike Christie
The previous patches converted iscsi_tcp to support sg chaining. This patch sets the proper flags and sets sg_table size to 4096. This allows fs io to be capped at max_sectors, but passthrough IO to be limited by some other part of the kernel. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-01-11[SCSI] iscsi_tcp: drop session when itt does not match any commandMike Christie
A target should never send us a itt that does not match a running task. If it does we do not really know what is coming down after the header, unless we evaluate the hdr and do some guessing sometimes. However, even if we know what is coming we probably do not have buffers for it or we cannot respond (if it is a r2t for example), so just drop the session. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-01-11[SCSI] iscsi_tcp: stop leaking r2t_info's when the incoming R2T is badOlaf Kirch
iscsi_r2t_rsp checks the incoming R2T for sanity, and if it thinks it's fishy, it will drop it silently. In this case, we leaked an r2t_info object. If we do this often enough, we run into a BUG_ON some time later. Removed r2t wrappers and update patch by Mike Christie 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>
2008-01-11[SCSI] iscsi: convert xmit path to iscsi chunksOlaf Kirch
Convert xmit to iscsi chunks. from michaelc@cs.wisc.edu: Bug fixes, more digest integration, sg chaining conversion and other sg wrapper changes, coding style sync up, and removal of io fields, like pdu_sent, that are not needed. 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>
2008-01-11[SCSI] libiscsi: fix nop handlingMike Christie
During root boot and shutdown the target could send us nops. At this time iscsid cannot be running, so the target will drop the session and the boot or shutdown will hang. To handle this and allow us to better control when to check the network this patch moves the nop handling to the kernel. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-01-11[SCSI] libiscsi: do not block session during logoutMike Christie
There is not need to block the session during logout. Since we are going to fail the commands that were blocked just fail them immediately instead. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-01-11[SCSI] libiscsi, iscsi_tcp: iscsi pool cleanupOlaf Kirch
iscsi_pool_init simplified iscsi_pool_init currently has a lot of duplicate kfree() calls it does when some allocation fails. This patch simplifies the code a little by using iscsi_pool_free to tear down the pool in case of an error. iscsi_pool_init also returns a copy of the item array to the caller. Not all callers use this array, so we make it optional. Instead of allocating a second array and return that, allocate just one array, of twice the size. Update users of iscsi_pool_{init,free} This patch drops the (now useless) second argument to iscsi_pool_free, and updates all callers. It also removes the ctask->r2ts array, which was never used anyway. Since the items argument to iscsi_pool_init is now optional, we can pass NULL instead. 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>
2008-01-11[SCSI] iscsi_tcp, libiscsi: initial AHS SupportBoaz Harrosh
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>