From bc0e17f691085315ae9303eb5b0883fe16dfe6b1 Mon Sep 17 00:00:00 2001 From: Vasu Dev Date: Fri, 27 Feb 2009 10:54:57 -0800 Subject: [SCSI] libfc, fcoe: fixed locking issues with lport->lp_mutex around lport->link_status The fcoe_xmit could call fc_pause in case the pending skb queue len is larger than FCOE_MAX_QUEUE_DEPTH, the fc_pause was trying to grab lport->lp_muex to change lport->link_status and that had these issues :- 1. The fcoe_xmit was getting called with bh disabled, thus causing "BUG: scheduling while atomic" when grabbing lport->lp_muex with bh disabled. 2. fc_linkup and fc_linkdown function calls lport_enter function with lport->lp_mutex held and these enter function in turn calls fcoe_xmit to send lport related FC frame, e.g. fc_linkup => fc_lport_enter_flogi to send flogi req. In this case grabbing the same lport->lp_mutex again in fc_puase from fcoe_xmit would cause deadlock. The lport->lp_mutex was used for setting FC_PAUSE in fcoe_xmit path but FC_PAUSE bit was not used anywhere beside just setting and clear this bit in lport->link_status, instead used a separate field qfull in fc_lport to eliminate need for lport->lp_mutex to track pending queue full condition and in turn avoid above described two locking issues. Also added check for lp->qfull in fc_fcp_lport_queue_ready to trigger SCSI_MLQUEUE_HOST_BUSY when lp->qfull is set to prevent more scsi-ml cmds while lp->qfull is set. This patch eliminated FC_LINK_UP and FC_PAUSE and instead used dedicated fields in fc_lport for this, this simplified all related conditional code. Also removed fc_pause and fc_unpause functions and instead used newly added lport->qfull directly in fcoe. Signed-off-by: Vasu Dev Signed-off-by: Robert Love Signed-off-by: James Bottomley --- drivers/scsi/libfc/fc_fcp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/scsi/libfc/fc_fcp.c') diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c index 404e63ff46b..f440aaca39c 100644 --- a/drivers/scsi/libfc/fc_fcp.c +++ b/drivers/scsi/libfc/fc_fcp.c @@ -1621,7 +1621,7 @@ out: static inline int fc_fcp_lport_queue_ready(struct fc_lport *lp) { /* lock ? */ - return (lp->state == LPORT_ST_READY) && (lp->link_status & FC_LINK_UP); + return (lp->state == LPORT_ST_READY) && lp->link_up && !lp->qfull; } /** @@ -1890,7 +1890,7 @@ int fc_eh_abort(struct scsi_cmnd *sc_cmd) lp = shost_priv(sc_cmd->device->host); if (lp->state != LPORT_ST_READY) return rc; - else if (!(lp->link_status & FC_LINK_UP)) + else if (!lp->link_up) return rc; spin_lock_irqsave(lp->host->host_lock, flags); -- cgit v1.2.3 From 26d9cab558f901051d0b69b2c445c8588931ce8d Mon Sep 17 00:00:00 2001 From: Vasu Dev Date: Fri, 27 Feb 2009 10:55:07 -0800 Subject: [SCSI] libfc: fixed a read IO data integrity issue when a IO data frame lost The fc_fcp_complete_locked detected data underrun in this case and set the FC_DATA_UNDRUN but that was ignored by fc_io_compl for all cases including read underrun. Added code to not to ignore FC_DATA_UNDRUN for read IO and instead suggested scsi-ml to retry cmd to recover from lost data frame. Not sure if it is okay to ignore FC_DATA_UNDRUN for other case, so let code as is for other cases but removed or-ing with zero valued fsp->cdb_status for those cases. Signed-off-by: Vasu Dev Signed-off-by: Robert Love Signed-off-by: James Bottomley --- drivers/scsi/libfc/fc_fcp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/scsi/libfc/fc_fcp.c') diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c index f440aaca39c..ecc72612c38 100644 --- a/drivers/scsi/libfc/fc_fcp.c +++ b/drivers/scsi/libfc/fc_fcp.c @@ -1810,12 +1810,12 @@ static void fc_io_compl(struct fc_fcp_pkt *fsp) sc_cmd->result = DID_ERROR << 16; break; case FC_DATA_UNDRUN: - if (fsp->cdb_status == 0) { + if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) { /* * scsi status is good but transport level - * underrun. for read it should be an error?? + * underrun. */ - sc_cmd->result = (DID_OK << 16) | fsp->cdb_status; + sc_cmd->result = DID_OK << 16; } else { /* * scsi got underrun, this is an error -- cgit v1.2.3 From 34f42a070fc98f5dc07e9fa2338b7b8d1dc347eb Mon Sep 17 00:00:00 2001 From: Robert Love Date: Fri, 27 Feb 2009 10:55:45 -0800 Subject: [SCSI] libfc, fcoe: Fix kerneldoc comments 1) Added '()' for function names in kerneldoc comments 2) Changed comment bookends from '**/' to '*/'. The comment on the the mailing list was that '**/' "is consistently unconventional. Not wrong, just odd." The Documentation/kernel-doc-nano-HOWTO.txt states that kerneldoc comment blocks should end with '**/' but most (if not all) instance I found under drivers/scsi/ were only using the '*/' so I converted to that style. 3) Removed incorrect linebreaks in kerneldoc comments where found 4) Removed a few unnecessary blank comment lines in kerneldoc comment blocks Signed-off-by: Robert Love Signed-off-by: James Bottomley --- drivers/scsi/libfc/fc_fcp.c | 46 ++++++++++++++++++++++----------------------- 1 file changed, 23 insertions(+), 23 deletions(-) (limited to 'drivers/scsi/libfc/fc_fcp.c') diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c index ecc72612c38..2a631d7dbce 100644 --- a/drivers/scsi/libfc/fc_fcp.c +++ b/drivers/scsi/libfc/fc_fcp.c @@ -161,7 +161,7 @@ static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lp, gfp_t gfp) } /** - * fc_fcp_pkt_release - release hold on scsi_pkt packet + * fc_fcp_pkt_release() - release hold on scsi_pkt packet * @fsp: fcp packet struct * * This is used by upper layer scsi driver. @@ -183,8 +183,7 @@ static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp) } /** - * fc_fcp_pkt_destory - release hold on scsi_pkt packet - * + * fc_fcp_pkt_destory() - release hold on scsi_pkt packet * @seq: exchange sequence * @fsp: fcp packet struct * @@ -199,7 +198,7 @@ static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp) } /** - * fc_fcp_lock_pkt - lock a packet and get a ref to it. + * fc_fcp_lock_pkt() - lock a packet and get a ref to it. * @fsp: fcp packet * * We should only return error if we return a command to scsi-ml before @@ -291,9 +290,7 @@ static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp) buf = fc_frame_payload_get(fp, 0); if (offset + len > fsp->data_len) { - /* - * this should never happen - */ + /* this should never happen */ if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) && fc_frame_crc_check(fp)) goto crc_err; @@ -387,8 +384,8 @@ crc_err: fc_fcp_complete_locked(fsp); } -/* - * fc_fcp_send_data - Send SCSI data to target. +/** + * fc_fcp_send_data() - Send SCSI data to target. * @fsp: ptr to fc_fcp_pkt * @sp: ptr to this sequence * @offset: starting offset for this data request @@ -610,8 +607,8 @@ static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp) } } -/* - * fc_fcp_reduce_can_queue - drop can_queue +/** + * fc_fcp_reduce_can_queue() - drop can_queue * @lp: lport to drop queueing for * * If we are getting memory allocation failures, then we may @@ -642,9 +639,11 @@ done: spin_unlock_irqrestore(lp->host->host_lock, flags); } -/* - * exch mgr calls this routine to process scsi - * exchanges. +/** + * fc_fcp_recv() - Reveive FCP frames + * @seq: The sequence the frame is on + * @fp: The FC frame + * @arg: The related FCP packet * * Return : None * Context : called from Soft IRQ context @@ -832,7 +831,7 @@ err: } /** - * fc_fcp_complete_locked - complete processing of a fcp packet + * fc_fcp_complete_locked() - complete processing of a fcp packet * @fsp: fcp packet * * This function may sleep if a timer is pending. The packet lock must be @@ -900,7 +899,7 @@ static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error) } /** - * fc_fcp_cleanup_each_cmd - run fn on each active command + * fc_fcp_cleanup_each_cmd() - Cleanup active commads * @lp: logical port * @id: target id * @lun: lun @@ -952,7 +951,7 @@ static void fc_fcp_abort_io(struct fc_lport *lp) } /** - * fc_fcp_pkt_send - send a fcp packet to the lower level. + * fc_fcp_pkt_send() - send a fcp packet to the lower level. * @lp: fc lport * @fsp: fc packet. * @@ -1727,7 +1726,7 @@ out: EXPORT_SYMBOL(fc_queuecommand); /** - * fc_io_compl - Handle responses for completed commands + * fc_io_compl() - Handle responses for completed commands * @fsp: scsi packet * * Translates a error to a Linux SCSI error. @@ -1857,7 +1856,7 @@ static void fc_io_compl(struct fc_fcp_pkt *fsp) } /** - * fc_fcp_complete - complete processing of a fcp packet + * fc_fcp_complete() - complete processing of a fcp packet * @fsp: fcp packet * * This function may sleep if a fsp timer is pending. @@ -1874,9 +1873,10 @@ void fc_fcp_complete(struct fc_fcp_pkt *fsp) EXPORT_SYMBOL(fc_fcp_complete); /** - * fc_eh_abort - Abort a command...from scsi host template + * fc_eh_abort() - Abort a command * @sc_cmd: scsi command to abort * + * From scsi host template. * send ABTS to the target device and wait for the response * sc_cmd is the pointer to the command to be aborted. */ @@ -1920,7 +1920,7 @@ release_pkt: EXPORT_SYMBOL(fc_eh_abort); /** - * fc_eh_device_reset: Reset a single LUN + * fc_eh_device_reset() Reset a single LUN * @sc_cmd: scsi command * * Set from scsi host template to send tm cmd to the target and wait for the @@ -1973,7 +1973,7 @@ out: EXPORT_SYMBOL(fc_eh_device_reset); /** - * fc_eh_host_reset - The reset function will reset the ports on the host. + * fc_eh_host_reset() - The reset function will reset the ports on the host. * @sc_cmd: scsi command */ int fc_eh_host_reset(struct scsi_cmnd *sc_cmd) @@ -1999,7 +1999,7 @@ int fc_eh_host_reset(struct scsi_cmnd *sc_cmd) EXPORT_SYMBOL(fc_eh_host_reset); /** - * fc_slave_alloc - configure queue depth + * fc_slave_alloc() - configure queue depth * @sdev: scsi device * * Configures queue depth based on host's cmd_per_len. If not set -- cgit v1.2.3