cregit-Linux how code gets into the kernel

Release 4.11 drivers/scsi/libfc/fc_fcp.c

Directory: drivers/scsi/libfc
/*
 * Copyright(c) 2007 Intel Corporation. All rights reserved.
 * Copyright(c) 2008 Red Hat, Inc.  All rights reserved.
 * Copyright(c) 2008 Mike Christie
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Maintained at www.Open-FCoE.org
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/scatterlist.h>
#include <linux/err.h>
#include <linux/crc32.h>
#include <linux/slab.h>

#include <scsi/scsi_tcq.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>

#include <scsi/fc/fc_fc2.h>

#include <scsi/libfc.h>
#include <scsi/fc_encode.h>

#include "fc_libfc.h"


static struct kmem_cache *scsi_pkt_cachep;

/* SRB state definitions */

#define FC_SRB_FREE		0		
/* cmd is free */

#define FC_SRB_CMD_SENT		(1 << 0)	
/* cmd has been sent */

#define FC_SRB_RCV_STATUS	(1 << 1)	
/* response has arrived */

#define FC_SRB_ABORT_PENDING	(1 << 2)	
/* cmd abort sent to device */

#define FC_SRB_ABORTED		(1 << 3)	
/* abort acknowledged */

#define FC_SRB_DISCONTIG	(1 << 4)	
/* non-sequential data recvd */

#define FC_SRB_COMPL		(1 << 5)	
/* fc_io_compl has been run */

#define FC_SRB_FCP_PROCESSING_TMO (1 << 6)	
/* timer function processing */


#define FC_SRB_READ		(1 << 1)

#define FC_SRB_WRITE		(1 << 0)

/*
 * The SCp.ptr should be tested and set under the scsi_pkt_queue lock
 */

#define CMD_SP(Cmnd)		    ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)

#define CMD_ENTRY_STATUS(Cmnd)	    ((Cmnd)->SCp.have_data_in)

#define CMD_COMPL_STATUS(Cmnd)	    ((Cmnd)->SCp.this_residual)

#define CMD_SCSI_STATUS(Cmnd)	    ((Cmnd)->SCp.Status)

#define CMD_RESID_LEN(Cmnd)	    ((Cmnd)->SCp.buffers_residual)

/**
 * struct fc_fcp_internal - FCP layer internal data
 * @scsi_pkt_pool: Memory pool to draw FCP packets from
 * @scsi_queue_lock: Protects the scsi_pkt_queue
 * @scsi_pkt_queue: Current FCP packets
 * @last_can_queue_ramp_down_time: ramp down time
 * @last_can_queue_ramp_up_time: ramp up time
 * @max_can_queue: max can_queue size
 */

struct fc_fcp_internal {
	
mempool_t		*scsi_pkt_pool;
	
spinlock_t		scsi_queue_lock;
	
struct list_head	scsi_pkt_queue;
	
unsigned long		last_can_queue_ramp_down_time;
	
unsigned long		last_can_queue_ramp_up_time;
	
int			max_can_queue;
};


#define fc_get_scsi_internal(x)	((struct fc_fcp_internal *)(x)->scsi_priv)

/*
 * function prototypes
 * FC scsi I/O related functions
 */
static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
static void fc_fcp_timeout(unsigned long);
static void fc_fcp_rec(struct fc_fcp_pkt *);
static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
static void fc_io_compl(struct fc_fcp_pkt *);

static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);

/*
 * command status codes
 */

#define FC_COMPLETE		0

#define FC_CMD_ABORTED		1

#define FC_CMD_RESET		2

#define FC_CMD_PLOGO		3

#define FC_SNS_RCV		4

#define FC_TRANS_ERR		5

#define FC_DATA_OVRRUN		6

#define FC_DATA_UNDRUN		7

#define FC_ERROR		8

#define FC_HRD_ERROR		9

#define FC_CRC_ERROR		10

#define FC_TIMED_OUT		11

#define FC_TRANS_RESET		12

/*
 * Error recovery timeout values.
 */

#define FC_SCSI_TM_TOV		(10 * HZ)

#define FC_HOST_RESET_TIMEOUT	(30 * HZ)

#define FC_CAN_QUEUE_PERIOD	(60 * HZ)


#define FC_MAX_ERROR_CNT	5

#define FC_MAX_RECOV_RETRY	3


#define FC_FCP_DFLT_QUEUE_DEPTH 32

/**
 * fc_fcp_pkt_alloc() - Allocate a fcp_pkt
 * @lport: The local port that the FCP packet is for
 * @gfp:   GFP flags for allocation
 *
 * Return value: fcp_pkt structure or null on allocation failure.
 * Context:      Can be called from process context, no lock is required.
 */



static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
{
	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
	struct fc_fcp_pkt *fsp;

	fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
	if (fsp) {
		memset(fsp, 0, sizeof(*fsp));
		fsp->lp = lport;
		fsp->xfer_ddp = FC_XID_UNKNOWN;
		atomic_set(&fsp->ref_cnt, 1);
		init_timer(&fsp->timer);
		fsp->timer.data = (unsigned long)fsp;
		INIT_LIST_HEAD(&fsp->list);
		spin_lock_init(&fsp->scsi_pkt_lock);
	} else {
		per_cpu_ptr(lport->stats, get_cpu())->FcpPktAllocFails++;
		put_cpu();
	}
	return fsp;
}


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/**
 * fc_fcp_pkt_release() - Release hold on a fcp_pkt
 * @fsp: The FCP packet to be released
 *
 * Context: Can be called from process or interrupt context,
 *          no lock is required.
 */



static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
{
	if (atomic_dec_and_test(&fsp->ref_cnt)) {
		struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);

		mempool_free(fsp, si->scsi_pkt_pool);
	}
}


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/**
 * fc_fcp_pkt_hold() - Hold a fcp_pkt
 * @fsp: The FCP packet to be held
 */



static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
{
	atomic_inc(&fsp->ref_cnt);
}


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/**
 * fc_fcp_pkt_destroy() - Release hold on a fcp_pkt
 * @seq: The sequence that the FCP packet is on (required by destructor API)
 * @fsp: The FCP packet to be released
 *
 * This routine is called by a destructor callback in the fc_exch_seq_send()
 * routine of the libfc Transport Template. The 'struct fc_seq' is a required
 * argument even though it is not used by this routine.
 *
 * Context: No locking required.
 */



static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
{
	fc_fcp_pkt_release(fsp);
}


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/**
 * fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
 * @fsp: The FCP packet to be locked and incremented
 *
 * We should only return error if we return a command to SCSI-ml before
 * getting a response. This can happen in cases where we send a abort, but
 * do not wait for the response and the abort and command can be passing
 * each other on the wire/network-layer.
 *
 * Note: this function locks the packet and gets a reference to allow
 * callers to call the completion function while the lock is held and
 * not have to worry about the packets refcount.
 *
 * TODO: Maybe we should just have callers grab/release the lock and
 * have a function that they call to verify the fsp and grab a ref if
 * needed.
 */



static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
{
	spin_lock_bh(&fsp->scsi_pkt_lock);
	if (fsp->state & FC_SRB_COMPL) {
		spin_unlock_bh(&fsp->scsi_pkt_lock);
		return -EPERM;
	}

	fc_fcp_pkt_hold(fsp);
	return 0;
}


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/**
 * fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
 *                       reference count
 * @fsp: The FCP packet to be unlocked and decremented
 */



static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
{
	spin_unlock_bh(&fsp->scsi_pkt_lock);
	fc_fcp_pkt_release(fsp);
}


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/**
 * fc_fcp_timer_set() - Start a timer for a fcp_pkt
 * @fsp:   The FCP packet to start a timer for
 * @delay: The timeout period in jiffies
 */



static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
{
	if (!(fsp->state & FC_SRB_COMPL)) {
		mod_timer(&fsp->timer, jiffies + delay);
		fsp->timer_delay = delay;
	}
}


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static void fc_fcp_abort_done(struct fc_fcp_pkt *fsp)
{
	fsp->state |= FC_SRB_ABORTED;
	fsp->state &= ~FC_SRB_ABORT_PENDING;

	if (fsp->wait_for_comp)
		complete(&fsp->tm_done);
	else
		fc_fcp_complete_locked(fsp);
}


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/**
 * fc_fcp_send_abort() - Send an abort for exchanges associated with a
 *                       fcp_pkt
 * @fsp: The FCP packet to abort exchanges on
 */



static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
{
	int rc;

	if (!fsp->seq_ptr)
		return -EINVAL;

	per_cpu_ptr(fsp->lp->stats, get_cpu())->FcpPktAborts++;
	put_cpu();

	fsp->state |= FC_SRB_ABORT_PENDING;
	rc = fc_seq_exch_abort(fsp->seq_ptr, 0);
	/*
         * fc_seq_exch_abort() might return -ENXIO if
         * the sequence is already completed
         */
	if (rc == -ENXIO) {
		fc_fcp_abort_done(fsp);
		rc = 0;
	}
	return rc;
}


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/**
 * fc_fcp_retry_cmd() - Retry a fcp_pkt
 * @fsp: The FCP packet to be retried
 *
 * Sets the status code to be FC_ERROR and then calls
 * fc_fcp_complete_locked() which in turn calls fc_io_compl().
 * fc_io_compl() will notify the SCSI-ml that the I/O is done.
 * The SCSI-ml will retry the command.
 */



static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp, int status_code)
{
	if (fsp->seq_ptr) {
		fc_exch_done(fsp->seq_ptr);
		fsp->seq_ptr = NULL;
	}

	fsp->state &= ~FC_SRB_ABORT_PENDING;
	fsp->io_status = 0;
	fsp->status_code = status_code;
	fc_fcp_complete_locked(fsp);
}


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/**
 * fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
 * @fsp: The FCP packet that will manage the DDP frames
 * @xid: The XID that will be used for the DDP exchange
 */



void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
{
	struct fc_lport *lport;

	lport = fsp->lp;
	if ((fsp->req_flags & FC_SRB_READ) &&
	    (lport->lro_enabled) && (lport->tt.ddp_setup)) {
		if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
					scsi_sg_count(fsp->cmd)))
			fsp->xfer_ddp = xid;
	}
}


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/**
 * fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
 *                     DDP related resources for a fcp_pkt
 * @fsp: The FCP packet that DDP had been used on
 */



void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
{
	struct fc_lport *lport;

	if (!fsp)
		return;

	if (fsp->xfer_ddp == FC_XID_UNKNOWN)
		return;

	lport = fsp->lp;
	if (lport->tt.ddp_done) {
		fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
		fsp->xfer_ddp = FC_XID_UNKNOWN;
	}
}


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/**
 * fc_fcp_can_queue_ramp_up() - increases can_queue
 * @lport: lport to ramp up can_queue
 */



static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
{
	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
	unsigned long flags;
	int can_queue;

	spin_lock_irqsave(lport->host->host_lock, flags);

	if (si->last_can_queue_ramp_up_time &&
	    (time_before(jiffies, si->last_can_queue_ramp_up_time +
			 FC_CAN_QUEUE_PERIOD)))
		goto unlock;

	if (time_before(jiffies, si->last_can_queue_ramp_down_time +
			FC_CAN_QUEUE_PERIOD))
		goto unlock;

	si->last_can_queue_ramp_up_time = jiffies;

	can_queue = lport->host->can_queue << 1;
	if (can_queue >= si->max_can_queue) {
		can_queue = si->max_can_queue;
		si->last_can_queue_ramp_down_time = 0;
	}
	lport->host->can_queue = can_queue;
	shost_printk(KERN_ERR, lport->host, "libfc: increased "
		     "can_queue to %d.\n", can_queue);

unlock:
	spin_unlock_irqrestore(lport->host->host_lock, flags);
}


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/**
 * fc_fcp_can_queue_ramp_down() - reduces can_queue
 * @lport: lport to reduce can_queue
 *
 * If we are getting memory allocation failures, then we may
 * be trying to execute too many commands. We let the running
 * commands complete or timeout, then try again with a reduced
 * can_queue. Eventually we will hit the point where we run
 * on all reserved structs.
 */



static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
{
	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
	unsigned long flags;
	int can_queue;

	spin_lock_irqsave(lport->host->host_lock, flags);

	if (si->last_can_queue_ramp_down_time &&
	    (time_before(jiffies, si->last_can_queue_ramp_down_time +
			 FC_CAN_QUEUE_PERIOD)))
		goto unlock;

	si->last_can_queue_ramp_down_time = jiffies;

	can_queue = lport->host->can_queue;
	can_queue >>= 1;
	if (!can_queue)
		can_queue = 1;
	lport->host->can_queue = can_queue;

unlock:
	spin_unlock_irqrestore(lport->host->host_lock, flags);
}


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/*
 * fc_fcp_frame_alloc() -  Allocates fc_frame structure and buffer.
 * @lport:      fc lport struct
 * @len:        payload length
 *
 * Allocates fc_frame structure and buffer but if fails to allocate
 * then reduce can_queue.
 */



static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
						  size_t len)
{
	struct fc_frame *fp;

	fp = fc_frame_alloc(lport, len);
	if (likely(fp))
		return fp;

	per_cpu_ptr(lport->stats, get_cpu())->FcpFrameAllocFails++;
	put_cpu();
	/* error case */
	fc_fcp_can_queue_ramp_down(lport);
	shost_printk(KERN_ERR, lport->host,
		     "libfc: Could not allocate frame, "
		     "reducing can_queue to %d.\n", lport->host->can_queue);
	return NULL;
}


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/**
 * get_fsp_rec_tov() - Helper function to get REC_TOV
 * @fsp: the FCP packet
 *
 * Returns rec tov in jiffies as rpriv->e_d_tov + 1 second
 */



static inline unsigned int get_fsp_rec_tov(struct fc_fcp_pkt *fsp)
{
	struct fc_rport_libfc_priv *rpriv = fsp->rport->dd_data;
	unsigned int e_d_tov = FC_DEF_E_D_TOV;

	if (rpriv && rpriv->e_d_tov > e_d_tov)
		e_d_tov = rpriv->e_d_tov;
	return msecs_to_jiffies(e_d_tov) + HZ;
}


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/**
 * fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
 * @fsp: The FCP packet the data is on
 * @fp:  The data frame
 */



static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
{
	struct scsi_cmnd *sc = fsp->cmd;
	struct fc_lport *lport = fsp->lp;
	struct fc_stats *stats;
	struct fc_frame_header *fh;
	size_t start_offset;
	size_t offset;
	u32 crc;
	u32 copy_len = 0;
	size_t len;
	void *buf;
	struct scatterlist *sg;
	u32 nents;
	u8 host_bcode = FC_COMPLETE;

	fh = fc_frame_header_get(fp);
	offset = ntohl(fh->fh_parm_offset);
	start_offset = offset;
	len = fr_len(fp) - sizeof(*fh);
	buf = fc_frame_payload_get(fp, 0);

	/*
         * if this I/O is ddped then clear it and initiate recovery since data
         * frames are expected to be placed directly in that case.
         *
         * Indicate error to scsi-ml because something went wrong with the
         * ddp handling to get us here.
         */
	if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
		fc_fcp_ddp_done(fsp);
		FC_FCP_DBG(fsp, "DDP I/O in fc_fcp_recv_data set ERROR\n");
		host_bcode = FC_ERROR;
		goto err;
	}
	if (offset + len > fsp->data_len) {
		/* this should never happen */
		if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
		    fc_frame_crc_check(fp))
			goto crc_err;
		FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
			   "data_len %x\n", len, offset, fsp->data_len);

		/* Data is corrupted indicate scsi-ml should retry */
		host_bcode = FC_DATA_OVRRUN;
		goto err;
	}
	if (offset != fsp->xfer_len)
		fsp->state |= FC_SRB_DISCONTIG;

	sg = scsi_sglist(sc);
	nents = scsi_sg_count(sc);

	if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
						    &offset, NULL);
	} else {
		crc = crc32(~0, (u8 *) fh, sizeof(*fh));
		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
						    &offset, &crc);
		buf = fc_frame_payload_get(fp, 0);
		if (len % 4)
			crc = crc32(crc, buf + len, 4 - (len % 4));

		if (~crc != le32_to_cpu(fr_crc(fp))) {
crc_err:
			stats = per_cpu_ptr(lport->stats, get_cpu());
			stats->ErrorFrames++;
			/* per cpu count, not total count, but OK for limit */
			if (stats->InvalidCRCCount++ < FC_MAX_ERROR_CNT)
				printk(KERN_WARNING "libfc: CRC error on data "
				       "frame for port (%6.6x)\n",
				       lport->port_id);
			put_cpu();
			/*
                         * Assume the frame is total garbage.
                         * We may have copied it over the good part
                         * of the buffer.
                         * If so, we need to retry the entire operation.
                         * Otherwise, ignore it.
                         */
			if (fsp->state & FC_SRB_DISCONTIG) {
				host_bcode = FC_CRC_ERROR;
				goto err;
			}
			return;
		}
	}

	if (fsp->xfer_contig_end == start_offset)
		fsp->xfer_contig_end += copy_len;
	fsp->xfer_len += copy_len;

	/*
         * In the very rare event that this data arrived after the response
         * and completes the transfer, call the completion handler.
         */
	if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
	    fsp->xfer_len == fsp->data_len - fsp->scsi_resid) {
		FC_FCP_DBG( fsp, "complete out-of-order sequence\n" );
		fc_fcp_complete_locked(fsp);
	}
	return;
err:
	fc_fcp_recovery(fsp, host_bcode);
}


Contributors
PersonTokensPropCommitsCommitProp
Robert Love40582.82%746.67%


John Fastabend306.13%16.67%


Vasu Dev295.93%213.33%


Joe Eykholt91.84%16.67%


Hannes Reinecke91.84%16.67%


Yi Zou51.02%16.67%


Christopher Leech10.20%16.67%


Hillf Danton10.20%16.67%


Total489100.00%15100.00%



/**
 * fc_fcp_send_data() - Send SCSI data to a target
 * @fsp:      The FCP packet the data is on
 * @sp:       The sequence the data is to be sent on
 * @offset:   The starting offset for this data request
 * @seq_blen: The burst length for this data request
 *
 * Called after receiving a Transfer Ready data descriptor.
 * If the LLD is capable of sequence offload then send down the
 * seq_blen amount of data in single frame, otherwise send
 * multiple frames of the maximum frame payload supported by
 * the target port.
 */



static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
			    size_t offset, size_t seq_blen)
{
	struct fc_exch *ep;
	struct scsi_cmnd *sc;
	struct scatterlist *sg;
	struct fc_frame *fp = NULL;
	struct fc_lport *lport = fsp->lp;
	struct page *page;
	size_t remaining;
	size_t t_blen;
	size_t tlen;
	size_t sg_bytes;
	size_t frame_offset, fh_parm_offset;
	size_t off;
	int error;
	void *data = NULL;
	void *page_addr;
	int using_sg = lport->sg_supp;
	u32 f_ctl;

	WARN_ON(seq_blen <= 0);
	if (unlikely(offset + seq_blen > fsp->data_len)) {
		/* this should never happen */
		FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
			   "offset %zx\n", seq_blen, offset);
		fc_fcp_send_abort(fsp);
		return 0;
	} else if (offset != fsp->xfer_len) {
		/* Out of Order Data Request - no problem, but unexpected. */
		FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
			   "seq_blen %zx offset %zx\n", seq_blen, offset);
	}

	/*
         * if LLD is capable of seq_offload then set transport
         * burst length (t_blen) to seq_blen, otherwise set t_blen
         * to max FC frame payload previously set in fsp->max_payload.
         */
	t_blen = fsp->max_payload;
	if (lport->seq_offload) {
		t_blen = min(seq_blen, (size_t)lport->lso_max);
		FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
			   fsp, seq_blen, lport->lso_max, t_blen);
	}

	if (t_blen > 512)
		t_blen &= ~(512 - 1);	/* round down to block size */
	sc = fsp->cmd;

	remaining = seq_blen;
	fh_parm_offset = frame_offset = offset;
	tlen = 0;
	seq = fc_seq_start_next(seq);
	f_ctl = FC_FC_REL_OFF;
	WARN_ON(!seq);

	sg = scsi_sglist(sc);

	while (remaining > 0 && sg) {
		if (offset >= sg->length) {
			offset -= sg->length;
			sg = sg_next(sg);
			continue;
		}
		if (!fp) {
			tlen = min(t_blen, remaining);

			/*
                         * TODO.  Temporary workaround.  fc_seq_send() can't
                         * handle odd lengths in non-linear skbs.
                         * This will be the final fragment only.
                         */
			if (tlen % 4)
				using_sg = 0;
			fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
			if (!fp)
				return -ENOMEM;

			data = fc_frame_header_get(fp) + 1;
			fh_parm_offset = frame_offset;
			fr_max_payload(fp) = fsp->max_payload;
		}

		off = offset + sg->offset;
		sg_bytes = min(tlen, sg->length - offset);
		sg_bytes = min(sg_bytes,
			       (size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
		page = sg_page(sg) + (off >> PAGE_SHIFT);
		if (using_sg) {
			get_page(page);
			skb_fill_page_desc(fp_skb(fp),
					   skb_shinfo(fp_skb(fp))->nr_frags,
					   page, off & ~PAGE_MASK, sg_bytes);
			fp_skb(fp)->data_len += sg_bytes;
			fr_len(fp) += sg_bytes;
			fp_skb(fp)->truesize += PAGE_SIZE;
		} else {
			/*
                         * The scatterlist item may be bigger than PAGE_SIZE,
                         * but we must not cross pages inside the kmap.
                         */
			page_addr = kmap_atomic(page);
			memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
			       sg_bytes);
			kunmap_atomic(page_addr);
			data += sg_bytes;
		}
		offset += sg_bytes;
		frame_offset += sg_bytes;
		tlen -= sg_bytes;
		remaining -= sg_bytes;

		if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
		    (tlen))
			continue;

		/*
                 * Send sequence with transfer sequence initiative in case
                 * this is last FCP frame of the sequence.
                 */
		if (remaining == 0)
			f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;

		ep = fc_seq_exch(seq);
		fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
			       FC_TYPE_FCP, f_ctl, fh_parm_offset);

		/*
                 * send fragment using for a sequence.
                 */
		error = fc_seq_send(lport, seq, fp);
		if (error) {
			WARN_ON(1);		/* send error should be rare */
			return error;
		}
		fp = NULL;
	}
	fsp->xfer_len += seq_blen;	/* premature count? */
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Robert Love54382.77%330.00%


Christopher Leech578.69%110.00%


Yi Zou487.32%330.00%


Vasu Dev60.91%110.00%


Hannes Reinecke20.30%220.00%


Total656100.00%10100.00%



/**
 * fc_fcp_abts_resp() - Receive an ABTS response
 * @fsp: The FCP packet that is being aborted
 * @fp:  The response frame
 */



static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
{
	int ba_done = 1;
	struct fc_ba_rjt *brp;
	struct fc_frame_header *fh;

	fh = fc_frame_header_get(fp);
	switch (fh->fh_r_ctl) {
	case FC_RCTL_BA_ACC:
		break;
	case FC_RCTL_BA_RJT:
		brp = fc_frame_payload_get(fp, sizeof(*brp));
		if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
			break;
		/* fall thru */
	default:
		/*
                 * we will let the command timeout
                 * and scsi-ml recover in this case,
                 * therefore cleared the ba_done flag.
                 */
		ba_done = 0;
	}

	if (ba_done)
		fc_fcp_abort_done(fsp);
}


Contributors
PersonTokensPropCommitsCommitProp
Robert Love9298.92%150.00%


Hannes Reinecke11.08%150.00%


Total93100.00%2100.00%



/**
 * fc_fcp_recv() - Receive an FCP frame
 * @seq: The sequence the frame is on
 * @fp:  The received frame
 * @arg: The related FCP packet
 *
 * Context: Called from Soft IRQ context. Can not be called
 *          holding the FCP packet list lock.
 */



static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
{
	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
	struct fc_lport *lport = fsp->lp;
	struct fc_frame_header *fh;
	struct fcp_txrdy *dd;
	u8 r_ctl;
	int rc = 0;

	if (IS_ERR(fp)) {
		fc_fcp_error(fsp, fp);
		return;
	}

	fh = fc_frame_header_get(fp);
	r_ctl = fh->fh_r_ctl;

	if (lport->state != LPORT_ST_READY) {
		FC_FCP_DBG(fsp, "lport state %d, ignoring r_ctl %x\n",
			   lport->state, r_ctl);
		goto out;
	}
	if (fc_fcp_lock_pkt(fsp))
		goto out;

	if (fh->fh_type == FC_TYPE_BLS) {
		fc_fcp_abts_resp(fsp, fp);
		goto unlock;
	}

	if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING)) {
		FC_FCP_DBG(fsp, "command aborted, ignoring r_ctl %x\n", r_ctl);
		goto unlock;
	}

	if (r_ctl == FC_RCTL_DD_DATA_DESC) {
		/*
                 * received XFER RDY from the target
                 * need to send data to the target
                 */
		WARN_ON