kernel/git/stable/linux-stable.git/include/scsi/libfc.h, branch linux-2.6.37.y

SCSI host lock push-down

2010-11-16T21:33:23+00:00

Move the mid-layer's ->queuecommand() invocation from being locked with the host lock to being unlocked to facilitate speeding up the critical path for drivers who don't need this lock taken anyway. The patch below presents a simple SCSI host lock push-down as an equivalent transformation. No locking or other behavior should change with this patch. All existing bugs and locking orders are preserved. Additionally, add one parameter to queuecommand, struct Scsi_Host * and remove one parameter from queuecommand, void (*done)(struct scsi_cmnd *) Scsi_Host* is a convenient pointer that most host drivers need anyway, and 'done' is redundant to struct scsi_cmnd->scsi_done. Minimal code disturbance was attempted with this change. Most drivers needed only two one-line modifications for their host lock push-down. Signed-off-by: Jeff Garzik Acked-by: James Bottomley Signed-off-by: Linus Torvalds

[SCSI] libfc: Do not let disc work cancel itself

2010-10-25T20:11:37+00:00

When number of NPIV ports created are greater than the xids allocated per pool -- for eg., creating 255 NPIV ports on a system with nr_cpu_ids of 32, with each pool containing 128 xids -- and then generating a link event - for eg., shutdown/no shutdown -- on the switch port causes the hang with the following stack trace. Call Trace: schedule_timeout+0x19d/0x230 wait_for_common+0xc0/0x170 __cancel_work_timer+0xcf/0x1b0 fc_disc_stop+0x16/0x30 [libfc] fc_lport_reset_locked+0x47/0x90 [libfc] fc_lport_enter_reset+0x67/0xe0 [libfc] fc_lport_disc_callback+0xbc/0xe0 [libfc] fc_disc_done+0xa8/0xf0 [libfc] fc_disc_timeout+0x29/0x40 [libfc] run_workqueue+0xb8/0x140 worker_thread+0x96/0x110 kthread+0x96/0xa0 child_rip+0xa/0x20 Fix is to not cancel the disc_work if discovery is already stopped, thus allowing lport state machine to restart and try discovery again. Signed-off-by: Bhanu Prakash Gollapudi Acked-by: Joe Eykholt Signed-off-by: Robert Love Signed-off-by: James Bottomley

[SCSI] libfc: don't require a local exchange for incoming requests

2010-07-28T14:06:02+00:00

Incoming requests shouldn't require a local exchange if we're just going to reply with one or two frames and don't expect anything further. Don't allocate exchanges for such requests until requested by the upper-layer protocol. The sequence is always NULL for new requests, so remove that as an argument to request handlers. Also change the first argument to lport->tt.seq_els_rsp_send from the sequence pointer to the received frame pointer, to supply the exchange IDs and destination ID info. Signed-off-by: Joe Eykholt Signed-off-by: Robert Love Signed-off-by: James Bottomley

[SCSI] libfc: add interface to allocate a sequence for incoming requests

2010-07-28T14:06:01+00:00

For incoming ELS and FCP requests, we often don't require an exchange and sequence, however, sometimes we do. For those cases, (primarily FCP requests for targets) add a function to set up the exchange and sequence. Signed-off-by: Joe Eykholt Signed-off-by: Robert Love Signed-off-by: James Bottomley

[SCSI] libfc: add fc_fill_reply_hdr() and fc_fill_hdr()

2010-07-28T14:06:00+00:00

Add functions to fill in an FC header given a request header. These reduces code lines in fc_lport and fc_rport and works without an exchange/sequence assigned. fc_fill_reply_hdr() fills a header for a final reply frame. fc_fill_hdr() which is similar but allows specifying the f_ctl parameter. Add defines for F_CTL values FC_FCTL_REQ and FC_FCTL_RESP. These can be used for most request and response sequences. v2 of patch adds a line to copy the frame encapsulation info from the received frame. Signed-off-by: Joe Eykholt Signed-off-by: Robert Love Signed-off-by: James Bottomley

[SCSI] libfc: add fc_frame_sid() and fc_frame_did() functions

2010-07-28T14:05:59+00:00

To pave the way for eliminating exchanges from incoming requests, add simple inline fc_frame_sid() and fc_frame_did() functions which get the FC_IDs from the frame header. This can be almost as efficient as getting them from the sequence/exchange. Move ntohll, htonll, ntoh24 and hton24 to since we need them there and that's included by Signed-off-by: Joe Eykholt Signed-off-by: Robert Love Signed-off-by: James Bottomley

[SCSI] libfc: eliminate rport LOGO state

2010-07-28T14:05:58+00:00

The LOGO state hasn't been used in a while, except in a brief transition to DELETE state while holding the rport mutex. All port LOGO responses have been ignored as well as any timeout if we don't get a response. So this patch just removes LOGO state and simplifies the response handler. Signed-off-by: Joe Eykholt Signed-off-by: Robert Love Signed-off-by: James Bottomley

[SCSI] libfc: track FIP exchanges

2010-07-28T14:05:54+00:00

When an exchange is received with a FIP encapsulation, we need to know that the response must be sent via FIP and what the original ELS opcode was. This becomes important for VN2VN mode, where we may receive FLOGI or LOGO from several peer VN_ports, and the LS_ACC or LS_RJT must be sent FIP-encapsulated with the correct sub-type. Add a field to the struct fc_frame, fr_encaps, to indicate the encapsulation values. That term is chosen to be neutral and LLD-agnostic in case non-FCoE/FIP LLDs might find it useful. The frame fr_encaps is transferred from the ingress frame to the exchange by fc_exch_recv_req(), and back to the outgoing frame by fc_seq_send(). This is taking the last byte in the skb->cb array. If needed, we could combine the info in sof, eof, flags, and encaps together into one field, but it'd be better to do that if and when its needed. Signed-off-by: Joe Eykholt Signed-off-by: Robert Love Signed-off-by: James Bottomley

[SCSI] libfc: add FLOGI state to rport for VN2VN

2010-07-28T14:05:53+00:00

The FIP proposal for VN_port to VN_port point-to-multipoint operation requires a FLOGI be sent to each remote port. The FLOGI is sent with the assigned S_ID and D_IDs of the local and remote ports. This and the response get FIP-encapsulated for Ethernet. Add FLOGI state to the remote port state machine. This will be skipped if not in point-to-multipoint mode. To reduce a little duplication between PLOGI and FLOGI response handling, added fc_rport_login_complete(), which handles the parameters for the rdata struct. Signed-off-by: Joe Eykholt Signed-off-by: Robert Love Signed-off-by: James Bottomley

[SCSI] libfc: Add local port point-to-multipoint flag

2010-07-28T14:05:53+00:00

For VN_port to VN_port mode, the transport sets the port_id and there's no lport FLOGI. This is similar to FC loop mode. Add a point_to_multipoint flag that indicates the local port is in point-to-multipoint mode. This skips FLOGI and discovery. It also skips resetting the port_id on resets other than link down. Add function fc_lport_set_local_id() that sets the local port_id. This is called by libfcoe on behalf of the low-level driver to set the port_id when the link comes up. Signed-off-by: Joe Eykholt Signed-off-by: Robert Love Signed-off-by: James Bottomley