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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright(c) 2007 Intel Corporation. All rights reserved.
  * Copyright(c) 2008 Red Hat, Inc.  All rights reserved.
  * Copyright(c) 2008 Mike Christie
  *
  * 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 "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)
 
 static struct libfc_cmd_priv *libfc_priv(struct scsi_cmnd *cmd)
 {
     return scsi_cmd_priv(cmd);
 }
 
 /**
  * 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(struct timer_list *);
 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;
         refcount_set(&fsp->ref_cnt, 1);
         timer_setup(&fsp->timer, NULL, 0);
         INIT_LIST_HEAD(&fsp->list);
         spin_lock_init(&fsp->scsi_pkt_lock);
     } else {
         this_cpu_inc(lport->stats->FcpPktAllocFails);
     }
     return fsp;
 }
 
 /**
  * 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 (refcount_dec_and_test(&fsp->ref_cnt)) {
         struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
 
         mempool_free(fsp, si->scsi_pkt_pool);
     }
 }
 
 /**
  * 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)
 {
     refcount_inc(&fsp->ref_cnt);
 }
 
 /**
  * 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);
 }
 
 /**
  * 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;
 }
 
 /**
  * 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);
 }
 
 /**
  * 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;
     }
 }
 
 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);
 }
 
 /**
  * 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;
 
     this_cpu_inc(fsp->lp->stats->FcpPktAborts);
 
     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;
 }
 
 /**
  * fc_fcp_retry_cmd() - Retry a fcp_pkt
  * @fsp: The FCP packet to be retried
  * @status_code: The FCP status code to set
  *
  * 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);
 }
 
 /**
  * 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;
     }
 }
 
 /**
  * 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;
     }
 }
 
 /**
  * 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);
 }
 
 /**
  * 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 bool 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;
     bool changed = false;
 
     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;
     changed = true;
 
 unlock:
     spin_unlock_irqrestore(lport->host->host_lock, flags);
     return changed;
 }
 
 /*
  * 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;
 
     this_cpu_inc(lport->stats->FcpFrameAllocFails);
     /* 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;
 }
 
 /**
  * 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;
 }
 
 /**
  * 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_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:
             this_cpu_inc(lport->stats->ErrorFrames);
             /* per cpu count, not total count, but OK for limit */
             if (this_cpu_inc_return(lport->stats->InvalidCRCCount) < FC_MAX_ERROR_CNT)
                 printk(KERN_WARNING "libfc: CRC error on data "
                        "frame for port (%6.6x)\n",
                        lport->port_id);
             /*
              * 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);
 }
 
 /**
  * fc_fcp_send_data() - Send SCSI data to a target
  * @fsp:      The FCP packet the data is on
  * @seq:      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;
 }
 
 /**
  * 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;
         fallthrough;
     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);
 }
 
 /**
  * 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(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
         dd = fc_frame_payload_get(fp, sizeof(*dd));
         WARN_ON(!dd);
 
         rc = fc_fcp_send_data(fsp, seq,
                       (size_t) ntohl(dd->ft_data_ro),
                       (size_t) ntohl(dd->ft_burst_len));
         if (!rc)
             seq->rec_data = fsp->xfer_len;
     } else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
         /*
          * received a DATA frame
          * next we will copy the data to the system buffer
          */
         WARN_ON(fr_len(fp) < sizeof(*fh));  /* len may be 0 */
         fc_fcp_recv_data(fsp, fp);
         seq->rec_data = fsp->xfer_contig_end;
     } else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
         WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 
         fc_fcp_resp(fsp, fp);
     } else {
         FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
     }
 unlock:
     fc_fcp_unlock_pkt(fsp);
 out:
     fc_frame_free(fp);
 }
 
 /**
  * fc_fcp_resp() - Handler for FCP responses
  * @fsp: The FCP packet the response is for
  * @fp:  The response frame
  */
 static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 {
     struct fc_frame_header *fh;
     struct fcp_resp *fc_rp;
     struct fcp_resp_ext *rp_ex;
     struct fcp_resp_rsp_info *fc_rp_info;
     u32 plen;
     u32 expected_len;
     u32 respl = 0;
     u32 snsl = 0;
     u8 flags = 0;
 
     plen = fr_len(fp);
     fh = (struct fc_frame_header *)fr_hdr(fp);
     if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
         goto len_err;
     plen -= sizeof(*fh);
     fc_rp = (struct fcp_resp *)(fh + 1);
     fsp->cdb_status = fc_rp->fr_status;
     flags = fc_rp->fr_flags;
     fsp->scsi_comp_flags = flags;
     expected_len = fsp->data_len;
 
     /* if ddp, update xfer len */
     fc_fcp_ddp_done(fsp);
 
     if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
         rp_ex = (void *)(fc_rp + 1);
         if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
             if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
                 goto len_err;
             fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
             if (flags & FCP_RSP_LEN_VAL) {
                 respl = ntohl(rp_ex->fr_rsp_len);
                 if ((respl != FCP_RESP_RSP_INFO_LEN4) &&
                     (respl != FCP_RESP_RSP_INFO_LEN8))
                     goto len_err;
                 if (fsp->wait_for_comp) {
                     /* Abuse cdb_status for rsp code */
                     fsp->cdb_status = fc_rp_info->rsp_code;
                     complete(&fsp->tm_done);
                     /*
                      * tmfs will not have any scsi cmd so
                      * exit here
                      */
                     return;
                 }
             }
             if (flags & FCP_SNS_LEN_VAL) {
                 snsl = ntohl(rp_ex->fr_sns_len);
                 if (snsl > SCSI_SENSE_BUFFERSIZE)
                     snsl = SCSI_SENSE_BUFFERSIZE;
                 memcpy(fsp->cmd->sense_buffer,
                        (char *)fc_rp_info + respl, snsl);
             }
         }
         if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
             if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
                 goto len_err;
             if (flags & FCP_RESID_UNDER) {
                 fsp->scsi_resid = ntohl(rp_ex->fr_resid);
                 /*
                  * The cmnd->underflow is the minimum number of
                  * bytes that must be transferred for this
                  * command.  Provided a sense condition is not
                  * present, make sure the actual amount
                  * transferred is at least the underflow value
                  * or fail.
                  */
                 if (!(flags & FCP_SNS_LEN_VAL) &&
                     (fc_rp->fr_status == 0) &&
                     (scsi_bufflen(fsp->cmd) -
                      fsp->scsi_resid) < fsp->cmd->underflow)
                     goto err;
                 expected_len -= fsp->scsi_resid;
             } else {
                 fsp->status_code = FC_ERROR;
             }
         }
     }
     fsp->state |= FC_SRB_RCV_STATUS;
 
     /*
      * Check for missing or extra data frames.
      */
     if (unlikely(fsp->cdb_status == SAM_STAT_GOOD &&
              fsp->xfer_len != expected_len)) {
         if (fsp->xfer_len < expected_len) {
             /*
              * Some data may be queued locally,
              * Wait a at least one jiffy to see if it is delivered.
              * If this expires without data, we may do SRR.
              */
             if (fsp->lp->qfull) {
                 FC_FCP_DBG(fsp, "tgt %6.6x queue busy retry\n",
                        fsp->rport->port_id);
                 return;
             }
             FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx data underrun "
                    "len %x, data len %x\n",
                    fsp->rport->port_id,
                    fsp->xfer_len, expected_len, fsp->data_len);
             fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
             return;
         }
         fsp->status_code = FC_DATA_OVRRUN;
         FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
                "len %x, data len %x\n",
                fsp->rport->port_id,
                fsp->xfer_len, expected_len, fsp->data_len);
     }
     fc_fcp_complete_locked(fsp);
     return;
 
 len_err:
     FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
            "snsl %u\n", flags, fr_len(fp), respl, snsl);
 err:
     fsp->status_code = FC_ERROR;
     fc_fcp_complete_locked(fsp);
 }
 
 /**
  * fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
  *                fcp_pkt lock held
  * @fsp: The FCP packet to be completed
  *
  * This function may sleep if a timer is pending. The packet lock must be
  * held, and the host lock must not be held.
  */
 static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
 {
     struct fc_lport *lport = fsp->lp;
     struct fc_seq *seq;
     struct fc_exch *ep;
     u32 f_ctl;
 
     if (fsp->state & FC_SRB_ABORT_PENDING)
         return;
 
     if (fsp->state & FC_SRB_ABORTED) {
         if (!fsp->status_code)
             fsp->status_code = FC_CMD_ABORTED;
     } else {
         /*
          * Test for transport underrun, independent of response
          * underrun status.
          */
         if (fsp->cdb_status == SAM_STAT_GOOD &&
             fsp->xfer_len < fsp->data_len && !fsp->io_status &&
             (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
              fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
             FC_FCP_DBG(fsp, "data underrun, xfer %zx data %x\n",
                     fsp->xfer_len, fsp->data_len);
             fsp->status_code = FC_DATA_UNDRUN;
         }
     }
 
     seq = fsp->seq_ptr;
     if (seq) {
         fsp->seq_ptr = NULL;
         if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
             struct fc_frame *conf_frame;
             struct fc_seq *csp;
 
             csp = fc_seq_start_next(seq);
             conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
             if (conf_frame) {
                 f_ctl = FC_FC_SEQ_INIT;
                 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
                 ep = fc_seq_exch(seq);
                 fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
                            ep->did, ep->sid,
                            FC_TYPE_FCP, f_ctl, 0);
                 fc_seq_send(lport, csp, conf_frame);
             }
         }
         fc_exch_done(seq);
     }
     /*
      * Some resets driven by SCSI are not I/Os and do not have
      * SCSI commands associated with the requests. We should not
      * call I/O completion if we do not have a SCSI command.
      */
     if (fsp->cmd)
         fc_io_compl(fsp);
 }
 
 /**
  * fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
  * @fsp:   The FCP packet whose exchanges should be canceled
  * @error: The reason for the cancellation
  */
 static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
 {
     if (fsp->seq_ptr) {
         fc_exch_done(fsp->seq_ptr);
         fsp->seq_ptr = NULL;
     }
     fsp->status_code = error;
 }
 
 /**
  * fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
  * @lport: The local port whose exchanges should be canceled
  * @id:    The target's ID
  * @lun:   The LUN
  * @error: The reason for cancellation
  *
  * If lun or id is -1, they are ignored.
  */
 static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
                     unsigned int lun, int error)
 {
     struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
     struct fc_fcp_pkt *fsp;
     struct scsi_cmnd *sc_cmd;
     unsigned long flags;
 
     spin_lock_irqsave(&si->scsi_queue_lock, flags);
 restart:
     list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
         sc_cmd = fsp->cmd;
         if (id != -1 && scmd_id(sc_cmd) != id)
             continue;
 
         if (lun != -1 && sc_cmd->device->lun != lun)
             continue;
 
         fc_fcp_pkt_hold(fsp);
         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
 
         spin_lock_bh(&fsp->scsi_pkt_lock);
         if (!(fsp->state & FC_SRB_COMPL)) {
             fsp->state |= FC_SRB_COMPL;
             /*
              * TODO: dropping scsi_pkt_lock and then reacquiring
              * again around fc_fcp_cleanup_cmd() is required,
              * since fc_fcp_cleanup_cmd() calls into
              * fc_seq_set_resp() and that func preempts cpu using
              * schedule. May be schedule and related code should be
              * removed instead of unlocking here to avoid scheduling
              * while atomic bug.
              */
             spin_unlock_bh(&fsp->scsi_pkt_lock);
 
             fc_fcp_cleanup_cmd(fsp, error);
 
             spin_lock_bh(&fsp->scsi_pkt_lock);
             fc_io_compl(fsp);
         }
         spin_unlock_bh(&fsp->scsi_pkt_lock);
 
         fc_fcp_pkt_release(fsp);
         spin_lock_irqsave(&si->scsi_queue_lock, flags);
         /*
          * while we dropped the lock multiple pkts could
          * have been released, so we have to start over.
          */
         goto restart;
     }
     spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
 }
 
 /**
  * fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
  * @lport: The local port whose exchanges are to be aborted
  */
 static void fc_fcp_abort_io(struct fc_lport *lport)
 {
     fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
 }
 
 /**
  * fc_fcp_pkt_send() - Send a fcp_pkt
  * @lport: The local port to send the FCP packet on
  * @fsp:   The FCP packet to send
  *
  * Return:  Zero for success and -1 for failure
  * Locks:   Called without locks held
  */
 static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
 {
     struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
     unsigned long flags;
     int rc;
 
     libfc_priv(fsp->cmd)->fsp = fsp;
     fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
     fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
 
     int_to_scsilun(fsp->cmd->device->lun, &fsp->cdb_cmd.fc_lun);
     memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
 
     spin_lock_irqsave(&si->scsi_queue_lock, flags);
     list_add_tail(&fsp->list, &si->scsi_pkt_queue);
     spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
     rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
     if (unlikely(rc)) {
         spin_lock_irqsave(&si->scsi_queue_lock, flags);
         libfc_priv(fsp->cmd)->fsp = NULL;
         list_del(&fsp->list);
         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
     }
 
     return rc;
 }
 
 /**
  * fc_fcp_cmd_send() - Send a FCP command
  * @lport: The local port to send the command on
  * @fsp:   The FCP packet the command is on
  * @resp:  The handler for the response
  */
 static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
                void (*resp)(struct fc_seq *,
                     struct fc_frame *fp,
                     void *arg))
 {
     struct fc_frame *fp;
     struct fc_seq *seq;
     struct fc_rport *rport;
     struct fc_rport_libfc_priv *rpriv;
     const size_t len = sizeof(fsp->cdb_cmd);
     int rc = 0;
 
     if (fc_fcp_lock_pkt(fsp))
         return 0;
 
     fp = fc_fcp_frame_alloc(lport, sizeof(fsp->cdb_cmd));
     if (!fp) {
         rc = -1;
         goto unlock;
     }
 
     memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
     fr_fsp(fp) = fsp;
     rport = fsp->rport;
     fsp->max_payload = rport->maxframe_size;
     rpriv = rport->dd_data;
 
     fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
                rpriv->local_port->port_id, FC_TYPE_FCP,
                FC_FCTL_REQ, 0);
 
     seq = fc_exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy, fsp, 0);
     if (!seq) {
         rc = -1;
         goto unlock;
     }
     fsp->seq_ptr = seq;
     fc_fcp_pkt_hold(fsp);   /* hold for fc_fcp_pkt_destroy */
 
     fsp->timer.function = fc_fcp_timeout;
     if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
         fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
 
 unlock:
     fc_fcp_unlock_pkt(fsp);
     return rc;
 }
 
 /**
  * fc_fcp_error() - Handler for FCP layer errors
  * @fsp: The FCP packet the error is on
  * @fp:  The frame that has errored
  */
 static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 {
     int error = PTR_ERR(fp);
 
     if (fc_fcp_lock_pkt(fsp))
         return;
 
     if (error == -FC_EX_CLOSED) {
         fc_fcp_retry_cmd(fsp, FC_ERROR);
         goto unlock;
     }
 
     /*
      * clear abort pending, because the lower layer
      * decided to force completion.
      */
     fsp->state &= ~FC_SRB_ABORT_PENDING;
     fsp->status_code = FC_CMD_PLOGO;
     fc_fcp_complete_locked(fsp);
 unlock:
     fc_fcp_unlock_pkt(fsp);
 }
 
 /**
  * fc_fcp_pkt_abort() - Abort a fcp_pkt
  * @fsp:   The FCP packet to abort on
  *
  * Called to send an abort and then wait for abort completion
  */
 static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
 {
     int rc = FAILED;
     unsigned long ticks_left;
 
     FC_FCP_DBG(fsp, "pkt abort state %x\n", fsp->state);
     if (fc_fcp_send_abort(fsp)) {
         FC_FCP_DBG(fsp, "failed to send abort\n");
         return FAILED;
     }
 
     if (fsp->state & FC_SRB_ABORTED) {
         FC_FCP_DBG(fsp, "target abort cmd  completed\n");
         return SUCCESS;
     }
 
     init_completion(&fsp->tm_done);
     fsp->wait_for_comp = 1;
 
     spin_unlock_bh(&fsp->scsi_pkt_lock);
     ticks_left = wait_for_completion_timeout(&fsp->tm_done,
                             FC_SCSI_TM_TOV);
     spin_lock_bh(&fsp->scsi_pkt_lock);
     fsp->wait_for_comp = 0;
 
     if (!ticks_left) {
         FC_FCP_DBG(fsp, "target abort cmd  failed\n");
     } else if (fsp->state & FC_SRB_ABORTED) {
         FC_FCP_DBG(fsp, "target abort cmd  passed\n");
         rc = SUCCESS;
         fc_fcp_complete_locked(fsp);
     }
 
     return rc;
 }
 
 /**
  * fc_lun_reset_send() - Send LUN reset command
  * @t: Timer context used to fetch the FSP packet
  */
 static void fc_lun_reset_send(struct timer_list *t)
 {
     struct fc_fcp_pkt *fsp = from_timer(fsp, t, timer);
     struct fc_lport *lport = fsp->lp;
 
     if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
         if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
             return;
         if (fc_fcp_lock_pkt(fsp))
             return;
         fsp->timer.function = fc_lun_reset_send;
         fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
         fc_fcp_unlock_pkt(fsp);
     }
 }
 
 /**
  * fc_lun_reset() - Send a LUN RESET command to a device
  *          and wait for the reply
  * @lport: The local port to sent the command on
  * @fsp:   The FCP packet that identifies the LUN to be reset
  * @id:    The SCSI command ID
  * @lun:   The LUN ID to be reset
  */
 static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
             unsigned int id, unsigned int lun)
 {
     int rc;
 
     fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
     fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
     int_to_scsilun(lun, &fsp->cdb_cmd.fc_lun);
 
     fsp->wait_for_comp = 1;
     init_completion(&fsp->tm_done);
 
     fc_lun_reset_send(&fsp->timer);
 
     /*
      * wait for completion of reset
      * after that make sure all commands are terminated
      */
     rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
 
     spin_lock_bh(&fsp->scsi_pkt_lock);
     fsp->state |= FC_SRB_COMPL;
     spin_unlock_bh(&fsp->scsi_pkt_lock);
 
     del_timer_sync(&fsp->timer);
 
     spin_lock_bh(&fsp->scsi_pkt_lock);
     if (fsp->seq_ptr) {
         fc_exch_done(fsp->seq_ptr);
         fsp->seq_ptr = NULL;
     }
     fsp->wait_for_comp = 0;
     spin_unlock_bh(&fsp->scsi_pkt_lock);
 
     if (!rc) {
         FC_SCSI_DBG(lport, "lun reset failed\n");
         return FAILED;
     }
 
     /* cdb_status holds the tmf's rsp code */
     if (fsp->cdb_status != FCP_TMF_CMPL)
         return FAILED;
 
     FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
     fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
     return SUCCESS;
 }
 
 /**
  * fc_tm_done() - Task Management response handler
  * @seq: The sequence that the response is on
  * @fp:  The response frame
  * @arg: The FCP packet the response is for
  */
 static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
 {
     struct fc_fcp_pkt *fsp = arg;
     struct fc_frame_header *fh;
 
     if (IS_ERR(fp)) {
         /*
          * If there is an error just let it timeout or wait
          * for TMF to be aborted if it timedout.
          *
          * scsi-eh will escalate for when either happens.
          */
         return;
     }
 
     if (fc_fcp_lock_pkt(fsp))
         goto out;
 
     /*
      * raced with eh timeout handler.
      */
     if (!fsp->seq_ptr || !fsp->wait_for_comp)
         goto out_unlock;
 
     fh = fc_frame_header_get(fp);
     if (fh->fh_type != FC_TYPE_BLS)
         fc_fcp_resp(fsp, fp);
     fsp->seq_ptr = NULL;
     fc_exch_done(seq);
 out_unlock:
     fc_fcp_unlock_pkt(fsp);
 out:
     fc_frame_free(fp);
 }
 
 /**
  * fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
  * @lport: The local port to be cleaned up
  */
 static void fc_fcp_cleanup(struct fc_lport *lport)
 {
     fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
 }
 
 /**
  * fc_fcp_timeout() - Handler for fcp_pkt timeouts
  * @t: Timer context used to fetch the FSP packet
  *
  * If REC is supported then just issue it and return. The REC exchange will
  * complete or time out and recovery can continue at that point. Otherwise,
  * if the response has been received without all the data it has been
  * ER_TIMEOUT since the response was received. If the response has not been
  * received we see if data was received recently. If it has been then we
  * continue waiting, otherwise, we abort the command.
  */
 static void fc_fcp_timeout(struct timer_list *t)
 {
     struct fc_fcp_pkt *fsp = from_timer(fsp, t, timer);
     struct fc_rport *rport = fsp->rport;
     struct fc_rport_libfc_priv *rpriv = rport->dd_data;
 
     if (fc_fcp_lock_pkt(fsp))
         return;
 
     if (fsp->cdb_cmd.fc_tm_flags)
         goto unlock;
 
     if (fsp->lp->qfull) {
         FC_FCP_DBG(fsp, "fcp timeout, resetting timer delay %d\n",
                fsp->timer_delay);
         fsp->timer.function = fc_fcp_timeout;
         fc_fcp_timer_set(fsp, fsp->timer_delay);
         goto unlock;
     }
     FC_FCP_DBG(fsp, "fcp timeout, delay %d flags %x state %x\n",
            fsp->timer_delay, rpriv->flags, fsp->state);
     fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
 
     if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
         fc_fcp_rec(fsp);
     else if (fsp->state & FC_SRB_RCV_STATUS)
         fc_fcp_complete_locked(fsp);
     else
         fc_fcp_recovery(fsp, FC_TIMED_OUT);
     fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
 unlock:
     fc_fcp_unlock_pkt(fsp);
 }
 
 /**
  * fc_fcp_rec() - Send a REC ELS request
  * @fsp: The FCP packet to send the REC request on
  */
 static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
 {
     struct fc_lport *lport;
     struct fc_frame *fp;
     struct fc_rport *rport;
     struct fc_rport_libfc_priv *rpriv;
 
     lport = fsp->lp;
     rport = fsp->rport;
     rpriv = rport->dd_data;
     if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
         fsp->status_code = FC_HRD_ERROR;
         fsp->io_status = 0;
         fc_fcp_complete_locked(fsp);
         return;
     }
 
     fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
     if (!fp)
         goto retry;
 
     fr_seq(fp) = fsp->seq_ptr;
     fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
                rpriv->local_port->port_id, FC_TYPE_ELS,
                FC_FCTL_REQ, 0);
     if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
                  fc_fcp_rec_resp, fsp,
                  2 * lport->r_a_tov)) {
         fc_fcp_pkt_hold(fsp);       /* hold while REC outstanding */
         return;
     }
 retry:
     if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
         fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
     else
         fc_fcp_recovery(fsp, FC_TIMED_OUT);
 }
 
 /**
  * fc_fcp_rec_resp() - Handler for REC ELS responses
  * @seq: The sequence the response is on
  * @fp:  The response frame
  * @arg: The FCP packet the response is on
  *
  * If the response is a reject then the scsi layer will handle
  * the timeout. If the response is a LS_ACC then if the I/O was not completed
  * set the timeout and return. If the I/O was completed then complete the
  * exchange and tell the SCSI layer.
  */
 static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
 {
     struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
     struct fc_els_rec_acc *recp;
     struct fc_els_ls_rjt *rjt;
     u32 e_stat;
     u8 opcode;
     u32 offset;
     enum dma_data_direction data_dir;
     enum fc_rctl r_ctl;
     struct fc_rport_libfc_priv *rpriv;
 
     if (IS_ERR(fp)) {
         fc_fcp_rec_error(fsp, fp);
         return;
     }
 
     if (fc_fcp_lock_pkt(fsp))
         goto out;
 
     fsp->recov_retry = 0;
     opcode = fc_frame_payload_op(fp);
     if (opcode == ELS_LS_RJT) {
         rjt = fc_frame_payload_get(fp, sizeof(*rjt));
         switch (rjt->er_reason) {
         default:
             FC_FCP_DBG(fsp,
                    "device %x invalid REC reject %d/%d\n",
                    fsp->rport->port_id, rjt->er_reason,
                    rjt->er_explan);
             fallthrough;
         case ELS_RJT_UNSUP:
             FC_FCP_DBG(fsp, "device does not support REC\n");
             rpriv = fsp->rport->dd_data;
             /*
              * if we do not spport RECs or got some bogus
              * reason then resetup timer so we check for
              * making progress.
              */
             rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
             break;
         case ELS_RJT_LOGIC:
         case ELS_RJT_UNAB:
             FC_FCP_DBG(fsp, "device %x REC reject %d/%d\n",
                    fsp->rport->port_id, rjt->er_reason,
                    rjt->er_explan);
             /*
              * If response got lost or is stuck in the
              * queue somewhere we have no idea if and when
              * the response will be received. So quarantine
              * the xid and retry the command.
              */
             if (rjt->er_explan == ELS_EXPL_OXID_RXID) {
                 struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
                 ep->state |= FC_EX_QUARANTINE;
                 fsp->state |= FC_SRB_ABORTED;
                 fc_fcp_retry_cmd(fsp, FC_TRANS_RESET);
                 break;
             }
             fc_fcp_recovery(fsp, FC_TRANS_RESET);
             break;
         }
     } else if (opcode == ELS_LS_ACC) {
         if (fsp->state & FC_SRB_ABORTED)
             goto unlock_out;
 
         data_dir = fsp->cmd->sc_data_direction;
         recp = fc_frame_payload_get(fp, sizeof(*recp));
         offset = ntohl(recp->reca_fc4value);
         e_stat = ntohl(recp->reca_e_stat);
 
         if (e_stat & ESB_ST_COMPLETE) {
 
             /*
              * The exchange is complete.
              *
              * For output, we must've lost the response.
              * For input, all data must've been sent.
              * We lost may have lost the response
              * (and a confirmation was requested) and maybe
              * some data.
              *
              * If all data received, send SRR
              * asking for response.  If partial data received,
              * or gaps, SRR requests data at start of gap.
              * Recovery via SRR relies on in-order-delivery.
              */
             if (data_dir == DMA_TO_DEVICE) {
                 r_ctl = FC_RCTL_DD_CMD_STATUS;
             } else if (fsp->xfer_contig_end == offset) {
                 r_ctl = FC_RCTL_DD_CMD_STATUS;
             } else {
                 offset = fsp->xfer_contig_end;
                 r_ctl = FC_RCTL_DD_SOL_DATA;
             }
             fc_fcp_srr(fsp, r_ctl, offset);
         } else if (e_stat & ESB_ST_SEQ_INIT) {
             /*
              * The remote port has the initiative, so just
              * keep waiting for it to complete.
              */
             fc_fcp_timer_set(fsp,  get_fsp_rec_tov(fsp));
         } else {
 
             /*
              * The exchange is incomplete, we have seq. initiative.
              * Lost response with requested confirmation,
              * lost confirmation, lost transfer ready or
              * lost write data.
              *
              * For output, if not all data was received, ask
              * for transfer ready to be repeated.
              *
              * If we received or sent all the data, send SRR to
              * request response.
              *
              * If we lost a response, we may have lost some read
              * data as well.
              */
             r_ctl = FC_RCTL_DD_SOL_DATA;
             if (data_dir == DMA_TO_DEVICE) {
                 r_ctl = FC_RCTL_DD_CMD_STATUS;
                 if (offset < fsp->data_len)
                     r_ctl = FC_RCTL_DD_DATA_DESC;
             } else if (offset == fsp->xfer_contig_end) {
                 r_ctl = FC_RCTL_DD_CMD_STATUS;
             } else if (fsp->xfer_contig_end < offset) {
                 offset = fsp->xfer_contig_end;
             }
             fc_fcp_srr(fsp, r_ctl, offset);
         }
     }
 unlock_out:
     fc_fcp_unlock_pkt(fsp);
 out:
     fc_fcp_pkt_release(fsp);    /* drop hold for outstanding REC */
     fc_frame_free(fp);
 }
 
 /**
  * fc_fcp_rec_error() - Handler for REC errors
  * @fsp: The FCP packet the error is on
  * @fp:  The REC frame
  */
 static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 {
     int error = PTR_ERR(fp);
 
     if (fc_fcp_lock_pkt(fsp))
         goto out;
 
     switch (error) {
     case -FC_EX_CLOSED:
         FC_FCP_DBG(fsp, "REC %p fid %6.6x exchange closed\n",
                fsp, fsp->rport->port_id);
         fc_fcp_retry_cmd(fsp, FC_ERROR);
         break;
 
     default:
         FC_FCP_DBG(fsp, "REC %p fid %6.6x error unexpected error %d\n",
                fsp, fsp->rport->port_id, error);
         fsp->status_code = FC_CMD_PLOGO;
         fallthrough;
 
     case -FC_EX_TIMEOUT:
         /*
          * Assume REC or LS_ACC was lost.
          * The exchange manager will have aborted REC, so retry.
          */
         FC_FCP_DBG(fsp, "REC %p fid %6.6x exchange timeout retry %d/%d\n",
                fsp, fsp->rport->port_id, fsp->recov_retry,
                FC_MAX_RECOV_RETRY);
         if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
             fc_fcp_rec(fsp);
         else
             fc_fcp_recovery(fsp, FC_ERROR);
         break;
     }
     fc_fcp_unlock_pkt(fsp);
 out:
     fc_fcp_pkt_release(fsp);    /* drop hold for outstanding REC */
 }
 
 /**
  * fc_fcp_recovery() - Handler for fcp_pkt recovery
  * @fsp: The FCP pkt that needs to be aborted
  * @code: The FCP status code to set
  */
 static void fc_fcp_recovery(struct fc_fcp_pkt *fsp, u8 code)
 {
     FC_FCP_DBG(fsp, "start recovery code %x\n", code);
     fsp->status_code = code;
     fsp->cdb_status = 0;
     fsp->io_status = 0;
     /*
      * if this fails then we let the scsi command timer fire and
      * scsi-ml escalate.
      */
     fc_fcp_send_abort(fsp);
 }
 
 /**
  * fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
  * @fsp:   The FCP packet the SRR is to be sent on
  * @r_ctl: The R_CTL field for the SRR request
  * @offset: The SRR relative offset
  * This is called after receiving status but insufficient data, or
  * when expecting status but the request has timed out.
  */
 static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
 {
     struct fc_lport *lport = fsp->lp;
     struct fc_rport *rport;
     struct fc_rport_libfc_priv *rpriv;
     struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
     struct fc_seq *seq;
     struct fcp_srr *srr;
     struct fc_frame *fp;
 
     rport = fsp->rport;
     rpriv = rport->dd_data;
 
     if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
         rpriv->rp_state != RPORT_ST_READY)
         goto retry;         /* shouldn't happen */
     fp = fc_fcp_frame_alloc(lport, sizeof(*srr));
     if (!fp)
         goto retry;
 
     srr = fc_frame_payload_get(fp, sizeof(*srr));
     memset(srr, 0, sizeof(*srr));
     srr->srr_op = ELS_SRR;
     srr->srr_ox_id = htons(ep->oxid);
     srr->srr_rx_id = htons(ep->rxid);
     srr->srr_r_ctl = r_ctl;
     srr->srr_rel_off = htonl(offset);
 
     fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
                rpriv->local_port->port_id, FC_TYPE_FCP,
                FC_FCTL_REQ, 0);
 
     seq = fc_exch_seq_send(lport, fp, fc_fcp_srr_resp,
                    fc_fcp_pkt_destroy,
                    fsp, get_fsp_rec_tov(fsp));
     if (!seq)
         goto retry;
 
     fsp->recov_seq = seq;
     fsp->xfer_len = offset;
     fsp->xfer_contig_end = offset;
     fsp->state &= ~FC_SRB_RCV_STATUS;
     fc_fcp_pkt_hold(fsp);       /* hold for outstanding SRR */
     return;
 retry:
     fc_fcp_retry_cmd(fsp, FC_TRANS_RESET);
 }
 
 /**
  * fc_fcp_srr_resp() - Handler for SRR response
  * @seq: The sequence the SRR is on
  * @fp:  The SRR frame
  * @arg: The FCP packet the SRR is on
  */
 static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
 {
     struct fc_fcp_pkt *fsp = arg;
     struct fc_frame_header *fh;
 
     if (IS_ERR(fp)) {
         fc_fcp_srr_error(fsp, fp);
         return;
     }
 
     if (fc_fcp_lock_pkt(fsp))
         goto out;
 
     fh = fc_frame_header_get(fp);
     /*
      * BUG? fc_fcp_srr_error calls fc_exch_done which would release
      * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
      * then fc_exch_timeout would be sending an abort. The fc_exch_done
      * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
      * an abort response though.
      */
     if (fh->fh_type == FC_TYPE_BLS) {
         fc_fcp_unlock_pkt(fsp);
         return;
     }
 
     switch (fc_frame_payload_op(fp)) {
     case ELS_LS_ACC:
         fsp->recov_retry = 0;
         fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
         break;
     case ELS_LS_RJT:
     default:
         fc_fcp_recovery(fsp, FC_ERROR);
         break;
     }
     fc_fcp_unlock_pkt(fsp);
 out:
     fc_exch_done(seq);
     fc_frame_free(fp);
 }
 
 /**
  * fc_fcp_srr_error() - Handler for SRR errors
  * @fsp: The FCP packet that the SRR error is on
  * @fp:  The SRR frame
  */
 static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 {
     if (fc_fcp_lock_pkt(fsp))
         goto out;
     switch (PTR_ERR(fp)) {
     case -FC_EX_TIMEOUT:
         FC_FCP_DBG(fsp, "SRR timeout, retries %d\n", fsp->recov_retry);
         if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
             fc_fcp_rec(fsp);
         else
             fc_fcp_recovery(fsp, FC_TIMED_OUT);
         break;
     case -FC_EX_CLOSED:         /* e.g., link failure */
         FC_FCP_DBG(fsp, "SRR error, exchange closed\n");
         fallthrough;
     default:
         fc_fcp_retry_cmd(fsp, FC_ERROR);
         break;
     }
     fc_fcp_unlock_pkt(fsp);
 out:
     fc_exch_done(fsp->recov_seq);
 }
 
 /**
  * fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
  * @lport: The local port to be checked
  */
 static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
 {
     /* lock ? */
     return (lport->state == LPORT_ST_READY) &&
         lport->link_up && !lport->qfull;
 }
 
 /**
  * fc_queuecommand() - The queuecommand function of the SCSI template
  * @shost: The Scsi_Host that the command was issued to
  * @sc_cmd:   The scsi_cmnd to be executed
  *
  * This is the i/o strategy routine, called by the SCSI layer.
  */
 int fc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc_cmd)
 {
     struct fc_lport *lport = shost_priv(shost);
     struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
     struct fc_fcp_pkt *fsp;
     int rval;
     int rc = 0;
 
     rval = fc_remote_port_chkready(rport);
     if (rval) {
         sc_cmd->result = rval;
         scsi_done(sc_cmd);
         return 0;
     }
 
     if (!*(struct fc_remote_port **)rport->dd_data) {
         /*
          * rport is transitioning from blocked/deleted to
          * online
          */
         sc_cmd->result = DID_IMM_RETRY << 16;
         scsi_done(sc_cmd);
         goto out;
     }
 
     if (!fc_fcp_lport_queue_ready(lport)) {
         if (lport->qfull) {
             if (fc_fcp_can_queue_ramp_down(lport))
                 shost_printk(KERN_ERR, lport->host,
                          "libfc: queue full, "
                          "reducing can_queue to %d.\n",
                          lport->host->can_queue);
         }
         rc = SCSI_MLQUEUE_HOST_BUSY;
         goto out;
     }
 
     fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
     if (fsp == NULL) {
         rc = SCSI_MLQUEUE_HOST_BUSY;
         goto out;
     }
 
     /*
      * build the libfc request pkt
      */
     fsp->cmd = sc_cmd;  /* save the cmd */
     fsp->rport = rport; /* set the remote port ptr */
 
     /*
      * set up the transfer length
      */
     fsp->data_len = scsi_bufflen(sc_cmd);
     fsp->xfer_len = 0;
 
     /*
      * setup the data direction
      */
     if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
         fsp->req_flags = FC_SRB_READ;
         this_cpu_inc(lport->stats->InputRequests);
         this_cpu_add(lport->stats->InputBytes, fsp->data_len);
     } else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
         fsp->req_flags = FC_SRB_WRITE;
         this_cpu_inc(lport->stats->OutputRequests);
         this_cpu_add(lport->stats->OutputBytes, fsp->data_len);
     } else {
         fsp->req_flags = 0;
         this_cpu_inc(lport->stats->ControlRequests);
     }
 
     /*
      * send it to the lower layer
      * if we get -1 return then put the request in the pending
      * queue.
      */
     rval = fc_fcp_pkt_send(lport, fsp);
     if (rval != 0) {
         fsp->state = FC_SRB_FREE;
         fc_fcp_pkt_release(fsp);
         rc = SCSI_MLQUEUE_HOST_BUSY;
     }
 out:
     return rc;
 }
 EXPORT_SYMBOL(fc_queuecommand);
 
 /**
  * fc_io_compl() - Handle responses for completed commands
  * @fsp: The FCP packet that is complete
  *
  * Translates fcp_pkt errors to a Linux SCSI errors.
  * The fcp packet lock must be held when calling.
  */
 static void fc_io_compl(struct fc_fcp_pkt *fsp)
 {
     struct fc_fcp_internal *si;
     struct scsi_cmnd *sc_cmd;
     struct fc_lport *lport;
     unsigned long flags;
 
     /* release outstanding ddp context */
     fc_fcp_ddp_done(fsp);
 
     fsp->state |= FC_SRB_COMPL;
     if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
         spin_unlock_bh(&fsp->scsi_pkt_lock);
         del_timer_sync(&fsp->timer);
         spin_lock_bh(&fsp->scsi_pkt_lock);
     }
 
     lport = fsp->lp;
     si = fc_get_scsi_internal(lport);
 
     /*
      * if can_queue ramp down is done then try can_queue ramp up
      * since commands are completing now.
      */
     if (si->last_can_queue_ramp_down_time)
         fc_fcp_can_queue_ramp_up(lport);
 
     sc_cmd = fsp->cmd;
     libfc_priv(sc_cmd)->status = fsp->cdb_status;
     switch (fsp->status_code) {
     case FC_COMPLETE:
         if (fsp->cdb_status == 0) {
             /*
              * good I/O status
              */
             sc_cmd->result = DID_OK << 16;
             if (fsp->scsi_resid)
                 libfc_priv(sc_cmd)->resid_len = fsp->scsi_resid;
         } else {
             /*
              * transport level I/O was ok but scsi
              * has non zero status
              */
             sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
         }
         break;
     case FC_ERROR:
         FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
                "due to FC_ERROR\n");
         sc_cmd->result = DID_ERROR << 16;
         break;
     case FC_DATA_UNDRUN:
         if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
             /*
              * scsi status is good but transport level
              * underrun.
              */
             if (fsp->state & FC_SRB_RCV_STATUS) {
                 sc_cmd->result = DID_OK << 16;
             } else {
                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml"
                        " due to FC_DATA_UNDRUN (trans)\n");
                 sc_cmd->result = DID_ERROR << 16;
             }
         } else {
             /*
              * scsi got underrun, this is an error
              */
             FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
                    "due to FC_DATA_UNDRUN (scsi)\n");
             libfc_priv(sc_cmd)->resid_len = fsp->scsi_resid;
             sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
         }
         break;
     case FC_DATA_OVRRUN:
         /*
          * overrun is an error
          */
         FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
                "due to FC_DATA_OVRRUN\n");
         sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
         break;
     case FC_CMD_ABORTED:
         if (host_byte(sc_cmd->result) == DID_TIME_OUT)
             FC_FCP_DBG(fsp, "Returning DID_TIME_OUT to scsi-ml "
                    "due to FC_CMD_ABORTED\n");
         else {
             FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
                    "due to FC_CMD_ABORTED\n");
             set_host_byte(sc_cmd, DID_ERROR);
         }
         sc_cmd->result |= fsp->io_status;
         break;
     case FC_CMD_RESET:
         FC_FCP_DBG(fsp, "Returning DID_RESET to scsi-ml "
                "due to FC_CMD_RESET\n");
         sc_cmd->result = (DID_RESET << 16);
         break;
     case FC_TRANS_RESET:
         FC_FCP_DBG(fsp, "Returning DID_SOFT_ERROR to scsi-ml "
                "due to FC_TRANS_RESET\n");
         sc_cmd->result = (DID_SOFT_ERROR << 16);
         break;
     case FC_HRD_ERROR:
         FC_FCP_DBG(fsp, "Returning DID_NO_CONNECT to scsi-ml "
                "due to FC_HRD_ERROR\n");
         sc_cmd->result = (DID_NO_CONNECT << 16);
         break;
     case FC_CRC_ERROR:
         FC_FCP_DBG(fsp, "Returning DID_PARITY to scsi-ml "
                "due to FC_CRC_ERROR\n");
         sc_cmd->result = (DID_PARITY << 16);
         break;
     case FC_TIMED_OUT:
         FC_FCP_DBG(fsp, "Returning DID_BUS_BUSY to scsi-ml "
                "due to FC_TIMED_OUT\n");
         sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
         break;
     default:
         FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
                "due to unknown error\n");
         sc_cmd->result = (DID_ERROR << 16);
         break;
     }
 
     if (lport->state != LPORT_ST_READY && fsp->status_code != FC_COMPLETE)
         sc_cmd->result = (DID_TRANSPORT_DISRUPTED << 16);
 
     spin_lock_irqsave(&si->scsi_queue_lock, flags);
     list_del(&fsp->list);
     libfc_priv(sc_cmd)->fsp = NULL;
     spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
     scsi_done(sc_cmd);
 
     /* release ref from initial allocation in queue command */
     fc_fcp_pkt_release(fsp);
 }
 
 /**
  * fc_eh_abort() - Abort a command
  * @sc_cmd: The SCSI command to abort
  *
  * From SCSI host template.
  * Send an ABTS to the target device and wait for the response.
  */
 int fc_eh_abort(struct scsi_cmnd *sc_cmd)
 {
     struct fc_fcp_pkt *fsp;
     struct fc_lport *lport;
     struct fc_fcp_internal *si;
     int rc = FAILED;
     unsigned long flags;
     int rval;
 
     rval = fc_block_scsi_eh(sc_cmd);
     if (rval)
         return rval;
 
     lport = shost_priv(sc_cmd->device->host);
     if (lport->state != LPORT_ST_READY)
         return rc;
     else if (!lport->link_up)
         return rc;
 
     si = fc_get_scsi_internal(lport);
     spin_lock_irqsave(&si->scsi_queue_lock, flags);
     fsp = libfc_priv(sc_cmd)->fsp;
     if (!fsp) {
         /* command completed while scsi eh was setting up */
         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
         return SUCCESS;
     }
     /* grab a ref so the fsp and sc_cmd cannot be released from under us */
     fc_fcp_pkt_hold(fsp);
     spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
 
     if (fc_fcp_lock_pkt(fsp)) {
         /* completed while we were waiting for timer to be deleted */
         rc = SUCCESS;
         goto release_pkt;
     }
 
     rc = fc_fcp_pkt_abort(fsp);
     fc_fcp_unlock_pkt(fsp);
 
 release_pkt:
     fc_fcp_pkt_release(fsp);
     return rc;
 }
 EXPORT_SYMBOL(fc_eh_abort);
 
 /**
  * fc_eh_device_reset() - Reset a single LUN
  * @sc_cmd: The SCSI command which identifies the device whose
  *      LUN is to be reset
  *
  * Set from SCSI host template.
  */
 int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
 {
     struct fc_lport *lport;
     struct fc_fcp_pkt *fsp;
     struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
     int rc = FAILED;
     int rval;
 
     rval = fc_block_scsi_eh(sc_cmd);
     if (rval)
         return rval;
 
     lport = shost_priv(sc_cmd->device->host);
 
     if (lport->state != LPORT_ST_READY)
         return rc;
 
     FC_SCSI_DBG(lport, "Resetting rport (%6.6x)\n", rport->port_id);
 
     fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
     if (fsp == NULL) {
         printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
         goto out;
     }
 
     /*
      * Build the libfc request pkt. Do not set the scsi cmnd, because
      * the sc passed in is not setup for execution like when sent
      * through the queuecommand callout.
      */
     fsp->rport = rport; /* set the remote port ptr */
 
     /*
      * flush outstanding commands
      */
     rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
     fsp->state = FC_SRB_FREE;
     fc_fcp_pkt_release(fsp);
 
 out:
     return rc;
 }
 EXPORT_SYMBOL(fc_eh_device_reset);
 
 /**
  * fc_eh_host_reset() - Reset a Scsi_Host.
  * @sc_cmd: The SCSI command that identifies the SCSI host to be reset
  */
 int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
 {
     struct Scsi_Host *shost = sc_cmd->device->host;
     struct fc_lport *lport = shost_priv(shost);
     unsigned long wait_tmo;
 
     FC_SCSI_DBG(lport, "Resetting host\n");
 
     fc_lport_reset(lport);
     wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
     while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
                                    wait_tmo))
         msleep(1000);
 
     if (fc_fcp_lport_queue_ready(lport)) {
         shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
                  "on port (%6.6x)\n", lport->port_id);
         return SUCCESS;
     } else {
         shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
                  "port (%6.6x) is not ready.\n",
                  lport->port_id);
         return FAILED;
     }
 }
 EXPORT_SYMBOL(fc_eh_host_reset);
 
 /**
  * fc_slave_alloc() - Configure the queue depth of a Scsi_Host
  * @sdev: The SCSI device that identifies the SCSI host
  *
  * Configures queue depth based on host's cmd_per_len. If not set
  * then we use the libfc default.
  */
 int fc_slave_alloc(struct scsi_device *sdev)
 {
     struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
 
     if (!rport || fc_remote_port_chkready(rport))
         return -ENXIO;
 
     scsi_change_queue_depth(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
     return 0;
 }
 EXPORT_SYMBOL(fc_slave_alloc);
 
 /**
  * fc_fcp_destroy() - Tear down the FCP layer for a given local port
  * @lport: The local port that no longer needs the FCP layer
  */
 void fc_fcp_destroy(struct fc_lport *lport)
 {
     struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
 
     if (!list_empty(&si->scsi_pkt_queue))
         printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
                "port (%6.6x)\n", lport->port_id);
 
     mempool_destroy(si->scsi_pkt_pool);
     kfree(si);
     lport->scsi_priv = NULL;
 }
 EXPORT_SYMBOL(fc_fcp_destroy);
 
 int fc_setup_fcp(void)
 {
     int rc = 0;
 
     scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
                         sizeof(struct fc_fcp_pkt),
                         0, SLAB_HWCACHE_ALIGN, NULL);
     if (!scsi_pkt_cachep) {
         printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
                "module load failed!");
         rc = -ENOMEM;
     }
 
     return rc;
 }
 
 void fc_destroy_fcp(void)
 {
     kmem_cache_destroy(scsi_pkt_cachep);
 }
 
 /**
  * fc_fcp_init() - Initialize the FCP layer for a local port
  * @lport: The local port to initialize the exchange layer for
  */
 int fc_fcp_init(struct fc_lport *lport)
 {
     int rc;
     struct fc_fcp_internal *si;
 
     if (!lport->tt.fcp_cmd_send)
         lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
 
     if (!lport->tt.fcp_cleanup)
         lport->tt.fcp_cleanup = fc_fcp_cleanup;
 
     if (!lport->tt.fcp_abort_io)
         lport->tt.fcp_abort_io = fc_fcp_abort_io;
 
     si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
     if (!si)
         return -ENOMEM;
     lport->scsi_priv = si;
     si->max_can_queue = lport->host->can_queue;
     INIT_LIST_HEAD(&si->scsi_pkt_queue);
     spin_lock_init(&si->scsi_queue_lock);
 
     si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
     if (!si->scsi_pkt_pool) {
         rc = -ENOMEM;
         goto free_internal;
     }
     return 0;
 
 free_internal:
     kfree(si);
     return rc;
 }
 EXPORT_SYMBOL(fc_fcp_init);

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