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Message-ID: <4BC46C01.4070307@vlnb.net>
Date: Tue, 13 Apr 2010 17:05:05 +0400
From: Vladislav Bolkhovitin <vst@...b.net>
To: linux-scsi@...r.kernel.org
CC: linux-kernel@...r.kernel.org,
scst-devel <scst-devel@...ts.sourceforge.net>,
James Bottomley <James.Bottomley@...senPartnership.com>,
Andrew Morton <akpm@...ux-foundation.org>,
FUJITA Tomonori <fujita.tomonori@....ntt.co.jp>,
Mike Christie <michaelc@...wisc.edu>,
Jeff Garzik <jeff@...zik.org>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Vu Pham <vuhuong@...lanox.com>,
Bart Van Assche <bart.vanassche@...il.com>,
James Smart <James.Smart@...lex.Com>,
Joe Eykholt <jeykholt@...co.com>, Andy Yan <ayan@...vell.com>,
linux-driver@...gic.com
Subject: Re: [PATCH][RFC 4/12/1/5] SCST core's scst_targ.c
This patch contains file scst_targ.c.
Signed-off-by: Vladislav Bolkhovitin <vst@...b.net>
---
scst_targ.c | 5712 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 5712 insertions(+)
diff -uprN orig/linux-2.6.33/drivers/scst/scst_targ.c linux-2.6.33/drivers/scst/scst_targ.c
--- orig/linux-2.6.33/drivers/scst/scst_targ.c
+++ linux-2.6.33/drivers/scst/scst_targ.c
@@ -0,0 +1,5712 @@
+/*
+ * scst_targ.c
+ *
+ * Copyright (C) 2004 - 2010 Vladislav Bolkhovitin <vst@...b.net>
+ * Copyright (C) 2004 - 2005 Leonid Stoljar
+ * Copyright (C) 2007 - 2010 ID7 Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2
+ * of the License.
+ *
+ * This program is distributed in the hope that 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.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/smp_lock.h>
+#include <linux/unistd.h>
+#include <linux/string.h>
+#include <linux/kthread.h>
+#include <linux/delay.h>
+#include <linux/ktime.h>
+
+#include "scst.h"
+#include "scst_priv.h"
+
+#if 0 /* Temporary left for future performance investigations */
+/* Deleting it don't forget to delete write_cmd_count */
+#define CONFIG_SCST_ORDERED_READS
+#endif
+
+#if 0 /* Let's disable it for now to see if users will complain about it */
+/* Deleting it don't forget to delete write_cmd_count */
+#define CONFIG_SCST_PER_DEVICE_CMD_COUNT_LIMIT
+#endif
+
+static void scst_cmd_set_sn(struct scst_cmd *cmd);
+static int __scst_init_cmd(struct scst_cmd *cmd);
+static void scst_finish_cmd_mgmt(struct scst_cmd *cmd);
+static struct scst_cmd *__scst_find_cmd_by_tag(struct scst_session *sess,
+ uint64_t tag, bool to_abort);
+static void scst_process_redirect_cmd(struct scst_cmd *cmd,
+ enum scst_exec_context context, int check_retries);
+
+static inline void scst_schedule_tasklet(struct scst_cmd *cmd)
+{
+ struct scst_tasklet *t = &scst_tasklets[smp_processor_id()];
+ unsigned long flags;
+
+ spin_lock_irqsave(&t->tasklet_lock, flags);
+ TRACE_DBG("Adding cmd %p to tasklet %d cmd list", cmd,
+ smp_processor_id());
+ list_add_tail(&cmd->cmd_list_entry, &t->tasklet_cmd_list);
+ spin_unlock_irqrestore(&t->tasklet_lock, flags);
+
+ tasklet_schedule(&t->tasklet);
+}
+
+/**
+ * scst_rx_cmd() - create new command
+ * @sess: SCST session
+ * @lun: LUN for the command
+ * @lun_len: length of the LUN in bytes
+ * @cdb: CDB of the command
+ * @cdb_len: length of the CDB in bytes
+ * @atomic: true, if current context is atomic
+ *
+ * Description:
+ * Creates new SCST command. Returns new command on success or
+ * NULL otherwise.
+ *
+ * Must not be called in parallel with scst_unregister_session() for the
+ * same session.
+ */
+struct scst_cmd *scst_rx_cmd(struct scst_session *sess,
+ const uint8_t *lun, int lun_len,
+ const uint8_t *cdb, int cdb_len, int atomic)
+{
+ struct scst_cmd *cmd;
+
+#ifdef CONFIG_SCST_EXTRACHECKS
+ if (unlikely(sess->shut_phase != SCST_SESS_SPH_READY)) {
+ PRINT_CRIT_ERROR("%s",
+ "New cmd while shutting down the session");
+ BUG();
+ }
+#endif
+
+ cmd = scst_alloc_cmd(atomic ? GFP_ATOMIC : GFP_KERNEL);
+ if (cmd == NULL)
+ goto out;
+
+ cmd->sess = sess;
+ cmd->tgt = sess->tgt;
+ cmd->tgtt = sess->tgt->tgtt;
+
+ cmd->lun = scst_unpack_lun(lun, lun_len);
+ if (unlikely(cmd->lun == NO_SUCH_LUN)) {
+ PRINT_ERROR("Wrong LUN %d, finishing cmd", -1);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_lun_not_supported));
+ }
+
+ /*
+ * For cdb_len 0 defer the error reporting until scst_cmd_init_done(),
+ * scst_set_cmd_error() supports nested calls.
+ */
+ if (unlikely(cdb_len > SCST_MAX_CDB_SIZE)) {
+ PRINT_ERROR("Too big CDB len %d, finishing cmd", cdb_len);
+ cdb_len = SCST_MAX_CDB_SIZE;
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_message));
+ }
+
+ memcpy(cmd->cdb, cdb, cdb_len);
+ cmd->cdb_len = cdb_len;
+
+ TRACE_DBG("cmd %p, sess %p", cmd, sess);
+ scst_sess_get(sess);
+
+out:
+ return cmd;
+}
+EXPORT_SYMBOL(scst_rx_cmd);
+
+/*
+ * No locks, but might be on IRQ. Returns 0 on success, <0 if processing of
+ * this command should be stopped.
+ */
+static int scst_init_cmd(struct scst_cmd *cmd, enum scst_exec_context *context)
+{
+ int rc, res = 0;
+
+ /* See the comment in scst_do_job_init() */
+ if (unlikely(!list_empty(&scst_init_cmd_list))) {
+ TRACE_MGMT_DBG("%s", "init cmd list busy");
+ goto out_redirect;
+ }
+ /*
+ * Memory barrier isn't necessary here, because CPU appears to
+ * be self-consistent and we don't care about the race, described
+ * in comment in scst_do_job_init().
+ */
+
+ rc = __scst_init_cmd(cmd);
+ if (unlikely(rc > 0))
+ goto out_redirect;
+ else if (unlikely(rc != 0)) {
+ res = 1;
+ goto out;
+ }
+
+ EXTRACHECKS_BUG_ON(*context == SCST_CONTEXT_SAME);
+
+ /* Small context optimization */
+ if (((*context == SCST_CONTEXT_TASKLET) ||
+ (*context == SCST_CONTEXT_DIRECT_ATOMIC)) &&
+ scst_cmd_is_expected_set(cmd)) {
+ if (cmd->expected_data_direction & SCST_DATA_WRITE) {
+ if (!test_bit(SCST_TGT_DEV_AFTER_INIT_WR_ATOMIC,
+ &cmd->tgt_dev->tgt_dev_flags))
+ *context = SCST_CONTEXT_THREAD;
+ } else {
+ if (!test_bit(SCST_TGT_DEV_AFTER_INIT_OTH_ATOMIC,
+ &cmd->tgt_dev->tgt_dev_flags))
+ *context = SCST_CONTEXT_THREAD;
+ }
+ }
+
+out:
+ return res;
+
+out_redirect:
+ if (cmd->preprocessing_only) {
+ /*
+ * Poor man solution for single threaded targets, where
+ * blocking receiver at least sometimes means blocking all.
+ * For instance, iSCSI target won't be able to receive
+ * Data-Out PDUs.
+ */
+ BUG_ON(*context != SCST_CONTEXT_DIRECT);
+ scst_set_busy(cmd);
+ scst_set_cmd_abnormal_done_state(cmd);
+ res = 1;
+ /* Keep initiator away from too many BUSY commands */
+ msleep(50);
+ } else {
+ unsigned long flags;
+ spin_lock_irqsave(&scst_init_lock, flags);
+ TRACE_MGMT_DBG("Adding cmd %p to init cmd list (scst_cmd_count "
+ "%d)", cmd, atomic_read(&scst_cmd_count));
+ list_add_tail(&cmd->cmd_list_entry, &scst_init_cmd_list);
+ if (test_bit(SCST_CMD_ABORTED, &cmd->cmd_flags))
+ scst_init_poll_cnt++;
+ spin_unlock_irqrestore(&scst_init_lock, flags);
+ wake_up(&scst_init_cmd_list_waitQ);
+ res = -1;
+ }
+ goto out;
+}
+
+/**
+ * scst_cmd_init_done() - the command's initialization done
+ * @cmd: SCST command
+ * @pref_context: preferred command execution context
+ *
+ * Description:
+ * Notifies SCST that the driver finished its part of the command
+ * initialization, and the command is ready for execution.
+ * The second argument sets preferred command execition context.
+ * See SCST_CONTEXT_* constants for details.
+ *
+ * !!IMPORTANT!!
+ *
+ * If cmd->set_sn_on_restart_cmd not set, this function, as well as
+ * scst_cmd_init_stage1_done() and scst_restart_cmd(), must not be
+ * called simultaneously for the same session (more precisely,
+ * for the same session/LUN, i.e. tgt_dev), i.e. they must be
+ * somehow externally serialized. This is needed to have lock free fast
+ * path in scst_cmd_set_sn(). For majority of targets those functions are
+ * naturally serialized by the single source of commands. Only iSCSI
+ * immediate commands with multiple connections per session seems to be an
+ * exception. For it, some mutex/lock shall be used for the serialization.
+ */
+void scst_cmd_init_done(struct scst_cmd *cmd,
+ enum scst_exec_context pref_context)
+{
+ unsigned long flags;
+ struct scst_session *sess = cmd->sess;
+ int rc;
+
+ scst_set_start_time(cmd);
+
+ TRACE_DBG("Preferred context: %d (cmd %p)", pref_context, cmd);
+ TRACE(TRACE_SCSI, "tag=%llu, lun=%lld, CDB len=%d, queue_type=%x "
+ "(cmd %p)", (long long unsigned int)cmd->tag,
+ (long long unsigned int)cmd->lun, cmd->cdb_len,
+ cmd->queue_type, cmd);
+ PRINT_BUFF_FLAG(TRACE_SCSI|TRACE_RCV_BOT, "Recieving CDB",
+ cmd->cdb, cmd->cdb_len);
+
+#ifdef CONFIG_SCST_EXTRACHECKS
+ if (unlikely((in_irq() || irqs_disabled())) &&
+ ((pref_context == SCST_CONTEXT_DIRECT) ||
+ (pref_context == SCST_CONTEXT_DIRECT_ATOMIC))) {
+ PRINT_ERROR("Wrong context %d in IRQ from target %s, use "
+ "SCST_CONTEXT_THREAD instead", pref_context,
+ cmd->tgtt->name);
+ pref_context = SCST_CONTEXT_THREAD;
+ }
+#endif
+
+ atomic_inc(&sess->sess_cmd_count);
+
+ spin_lock_irqsave(&sess->sess_list_lock, flags);
+
+ if (unlikely(sess->init_phase != SCST_SESS_IPH_READY)) {
+ /*
+ * We must always keep commands in the sess list from the
+ * very beginning, because otherwise they can be missed during
+ * TM processing. This check is needed because there might be
+ * old, i.e. deferred, commands and new, i.e. just coming, ones.
+ */
+ if (cmd->sess_cmd_list_entry.next == NULL)
+ list_add_tail(&cmd->sess_cmd_list_entry,
+ &sess->sess_cmd_list);
+ switch (sess->init_phase) {
+ case SCST_SESS_IPH_SUCCESS:
+ break;
+ case SCST_SESS_IPH_INITING:
+ TRACE_DBG("Adding cmd %p to init deferred cmd list",
+ cmd);
+ list_add_tail(&cmd->cmd_list_entry,
+ &sess->init_deferred_cmd_list);
+ spin_unlock_irqrestore(&sess->sess_list_lock, flags);
+ goto out;
+ case SCST_SESS_IPH_FAILED:
+ spin_unlock_irqrestore(&sess->sess_list_lock, flags);
+ scst_set_busy(cmd);
+ scst_set_cmd_abnormal_done_state(cmd);
+ goto active;
+ default:
+ BUG();
+ }
+ } else
+ list_add_tail(&cmd->sess_cmd_list_entry,
+ &sess->sess_cmd_list);
+
+ spin_unlock_irqrestore(&sess->sess_list_lock, flags);
+
+ if (unlikely(cmd->cdb_len == 0)) {
+ PRINT_ERROR("%s", "Wrong CDB len 0, finishing cmd");
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_opcode));
+ scst_set_cmd_abnormal_done_state(cmd);
+ goto active;
+ }
+
+ if (unlikely(cmd->queue_type >= SCST_CMD_QUEUE_ACA)) {
+ PRINT_ERROR("Unsupported queue type %d", cmd->queue_type);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_message));
+ goto active;
+ }
+
+ /*
+ * Cmd must be inited here to preserve the order. In case if cmd
+ * already preliminary completed by target driver we need to init
+ * cmd anyway to find out in which format we should return sense.
+ */
+ cmd->state = SCST_CMD_STATE_INIT;
+ rc = scst_init_cmd(cmd, &pref_context);
+ if (unlikely(rc < 0))
+ goto out;
+
+active:
+ /* Here cmd must not be in any cmd list, no locks */
+ switch (pref_context) {
+ case SCST_CONTEXT_TASKLET:
+ scst_schedule_tasklet(cmd);
+ break;
+
+ case SCST_CONTEXT_DIRECT:
+ scst_process_active_cmd(cmd, false);
+ break;
+
+ case SCST_CONTEXT_DIRECT_ATOMIC:
+ scst_process_active_cmd(cmd, true);
+ break;
+
+ default:
+ PRINT_ERROR("Context %x is undefined, using the thread one",
+ pref_context);
+ /* go through */
+ case SCST_CONTEXT_THREAD:
+ spin_lock_irqsave(&cmd->cmd_threads->cmd_list_lock, flags);
+ TRACE_DBG("Adding cmd %p to active cmd list", cmd);
+ if (unlikely(cmd->queue_type == SCST_CMD_QUEUE_HEAD_OF_QUEUE))
+ list_add(&cmd->cmd_list_entry,
+ &cmd->cmd_threads->active_cmd_list);
+ else
+ list_add_tail(&cmd->cmd_list_entry,
+ &cmd->cmd_threads->active_cmd_list);
+ wake_up(&cmd->cmd_threads->cmd_list_waitQ);
+ spin_unlock_irqrestore(&cmd->cmd_threads->cmd_list_lock, flags);
+ break;
+ }
+
+out:
+ return;
+}
+EXPORT_SYMBOL(scst_cmd_init_done);
+
+static int scst_pre_parse(struct scst_cmd *cmd)
+{
+ int res = SCST_CMD_STATE_RES_CONT_SAME;
+ struct scst_device *dev = cmd->dev;
+ int rc;
+
+#ifdef CONFIG_SCST_STRICT_SERIALIZING
+ cmd->inc_expected_sn_on_done = 1;
+#else
+ cmd->inc_expected_sn_on_done = dev->handler->exec_sync ||
+ (!dev->has_own_order_mgmt &&
+ (dev->queue_alg == SCST_CONTR_MODE_QUEUE_ALG_RESTRICTED_REORDER ||
+ cmd->queue_type == SCST_CMD_QUEUE_ORDERED));
+#endif
+
+ /*
+ * Expected transfer data supplied by the SCSI transport via the
+ * target driver are untrusted, so we prefer to fetch them from CDB.
+ * Additionally, not all transports support supplying the expected
+ * transfer data.
+ */
+
+ rc = scst_get_cdb_info(cmd);
+ if (unlikely(rc != 0)) {
+ if (rc > 0) {
+ PRINT_BUFFER("Failed CDB", cmd->cdb, cmd->cdb_len);
+ goto out_err;
+ }
+
+ EXTRACHECKS_BUG_ON(cmd->op_flags & SCST_INFO_VALID);
+
+ cmd->cdb_len = scst_get_cdb_len(cmd->cdb);
+
+ TRACE(TRACE_MINOR, "Unknown opcode 0x%02x for %s. "
+ "Should you update scst_scsi_op_table?",
+ cmd->cdb[0], dev->handler->name);
+ PRINT_BUFF_FLAG(TRACE_MINOR, "Failed CDB", cmd->cdb,
+ cmd->cdb_len);
+ } else {
+ EXTRACHECKS_BUG_ON(!(cmd->op_flags & SCST_INFO_VALID));
+ }
+
+ cmd->state = SCST_CMD_STATE_DEV_PARSE;
+
+ TRACE_DBG("op_name <%s> (cmd %p), direction=%d "
+ "(expected %d, set %s), transfer_len=%d (expected "
+ "len %d), flags=%d", cmd->op_name, cmd,
+ cmd->data_direction, cmd->expected_data_direction,
+ scst_cmd_is_expected_set(cmd) ? "yes" : "no",
+ cmd->bufflen, cmd->expected_transfer_len,
+ cmd->op_flags);
+
+out:
+ return res;
+
+out_err:
+ scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_invalid_field_in_cdb));
+ scst_set_cmd_abnormal_done_state(cmd);
+ res = SCST_CMD_STATE_RES_CONT_SAME;
+ goto out;
+}
+
+#ifndef CONFIG_SCST_USE_EXPECTED_VALUES
+static bool scst_is_allowed_to_mismatch_cmd(struct scst_cmd *cmd)
+{
+ bool res = false;
+
+ /* VERIFY commands with BYTCHK unset shouldn't fail here */
+ if ((cmd->op_flags & SCST_VERIFY_BYTCHK_MISMATCH_ALLOWED) &&
+ (cmd->cdb[1] & BYTCHK) == 0) {
+ res = true;
+ goto out;
+ }
+
+ switch (cmd->cdb[0]) {
+ case TEST_UNIT_READY:
+ /* Crazy VMware people sometimes do TUR with READ direction */
+ res = true;
+ break;
+ }
+
+out:
+ return res;
+}
+#endif
+
+static int scst_parse_cmd(struct scst_cmd *cmd)
+{
+ int res = SCST_CMD_STATE_RES_CONT_SAME;
+ int state;
+ struct scst_device *dev = cmd->dev;
+ int orig_bufflen = cmd->bufflen;
+
+ if (likely(!scst_is_cmd_fully_local(cmd))) {
+ if (unlikely(!dev->handler->parse_atomic &&
+ scst_cmd_atomic(cmd))) {
+ /*
+ * It shouldn't be because of the SCST_TGT_DEV_AFTER_*
+ * optimization.
+ */
+ TRACE_DBG("Dev handler %s parse() needs thread "
+ "context, rescheduling", dev->handler->name);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ goto out;
+ }
+
+ TRACE_DBG("Calling dev handler %s parse(%p)",
+ dev->handler->name, cmd);
+ TRACE_BUFF_FLAG(TRACE_SND_BOT, "Parsing: ",
+ cmd->cdb, cmd->cdb_len);
+ scst_set_cur_start(cmd);
+ state = dev->handler->parse(cmd);
+ /* Caution: cmd can be already dead here */
+ TRACE_DBG("Dev handler %s parse() returned %d",
+ dev->handler->name, state);
+
+ switch (state) {
+ case SCST_CMD_STATE_NEED_THREAD_CTX:
+ scst_set_parse_time(cmd);
+ TRACE_DBG("Dev handler %s parse() requested thread "
+ "context, rescheduling", dev->handler->name);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ goto out;
+
+ case SCST_CMD_STATE_STOP:
+ TRACE_DBG("Dev handler %s parse() requested stop "
+ "processing", dev->handler->name);
+ res = SCST_CMD_STATE_RES_CONT_NEXT;
+ goto out;
+ }
+
+ scst_set_parse_time(cmd);
+
+ if (state == SCST_CMD_STATE_DEFAULT)
+ state = SCST_CMD_STATE_PREPARE_SPACE;
+ } else
+ state = SCST_CMD_STATE_PREPARE_SPACE;
+
+ if (unlikely(state == SCST_CMD_STATE_PRE_XMIT_RESP))
+ goto set_res;
+
+ if (unlikely(!(cmd->op_flags & SCST_INFO_VALID))) {
+#ifdef CONFIG_SCST_USE_EXPECTED_VALUES
+ if (scst_cmd_is_expected_set(cmd)) {
+ TRACE(TRACE_MINOR, "Using initiator supplied values: "
+ "direction %d, transfer_len %d",
+ cmd->expected_data_direction,
+ cmd->expected_transfer_len);
+ cmd->data_direction = cmd->expected_data_direction;
+ cmd->bufflen = cmd->expected_transfer_len;
+ } else {
+ PRINT_ERROR("Unknown opcode 0x%02x for %s and "
+ "target %s not supplied expected values",
+ cmd->cdb[0], dev->handler->name, cmd->tgtt->name);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_opcode));
+ goto out_done;
+ }
+#else
+ PRINT_ERROR("Unknown opcode %x", cmd->cdb[0]);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_opcode));
+ goto out_done;
+#endif
+ }
+
+ if (unlikely(cmd->cdb_len == -1)) {
+ PRINT_ERROR("Unable to get CDB length for "
+ "opcode 0x%02x. Returning INVALID "
+ "OPCODE", cmd->cdb[0]);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_opcode));
+ goto out_done;
+ }
+
+ EXTRACHECKS_BUG_ON(cmd->cdb_len == 0);
+
+ TRACE(TRACE_SCSI, "op_name <%s> (cmd %p), direction=%d "
+ "(expected %d, set %s), transfer_len=%d (expected "
+ "len %d), flags=%d", cmd->op_name, cmd,
+ cmd->data_direction, cmd->expected_data_direction,
+ scst_cmd_is_expected_set(cmd) ? "yes" : "no",
+ cmd->bufflen, cmd->expected_transfer_len,
+ cmd->op_flags);
+
+ if (unlikely((cmd->op_flags & SCST_UNKNOWN_LENGTH) != 0)) {
+ if (scst_cmd_is_expected_set(cmd)) {
+ /*
+ * Command data length can't be easily
+ * determined from the CDB. ToDo, all such
+ * commands processing should be fixed. Until
+ * it's done, get the length from the supplied
+ * expected value, but limit it to some
+ * reasonable value (15MB).
+ */
+ cmd->bufflen = min(cmd->expected_transfer_len,
+ 15*1024*1024);
+ cmd->op_flags &= ~SCST_UNKNOWN_LENGTH;
+ } else {
+ PRINT_ERROR("Unknown data transfer length for opcode "
+ "0x%x (handler %s, target %s)", cmd->cdb[0],
+ dev->handler->name, cmd->tgtt->name);
+ PRINT_BUFFER("Failed CDB", cmd->cdb, cmd->cdb_len);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_message));
+ goto out_done;
+ }
+ }
+
+ if (unlikely(cmd->cdb[cmd->cdb_len - 1] & CONTROL_BYTE_NACA_BIT)) {
+ PRINT_ERROR("NACA bit in control byte CDB is not supported "
+ "(opcode 0x%02x)", cmd->cdb[0]);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_field_in_cdb));
+ goto out_done;
+ }
+
+ if (unlikely(cmd->cdb[cmd->cdb_len - 1] & CONTROL_BYTE_LINK_BIT)) {
+ PRINT_ERROR("Linked commands are not supported "
+ "(opcode 0x%02x)", cmd->cdb[0]);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_field_in_cdb));
+ goto out_done;
+ }
+
+ if (cmd->dh_data_buf_alloced &&
+ unlikely((orig_bufflen > cmd->bufflen))) {
+ PRINT_ERROR("Dev handler supplied data buffer (size %d), "
+ "is less, than required (size %d)", cmd->bufflen,
+ orig_bufflen);
+ PRINT_BUFFER("Failed CDB", cmd->cdb, cmd->cdb_len);
+ goto out_hw_error;
+ }
+
+#ifdef CONFIG_SCST_EXTRACHECKS
+ if ((cmd->bufflen != 0) &&
+ ((cmd->data_direction == SCST_DATA_NONE) ||
+ ((cmd->sg == NULL) && (state > SCST_CMD_STATE_PREPARE_SPACE)))) {
+ PRINT_ERROR("Dev handler %s parse() returned "
+ "invalid cmd data_direction %d, bufflen %d, state %d "
+ "or sg %p (opcode 0x%x)", dev->handler->name,
+ cmd->data_direction, cmd->bufflen, state, cmd->sg,
+ cmd->cdb[0]);
+ PRINT_BUFFER("Failed CDB", cmd->cdb, cmd->cdb_len);
+ goto out_hw_error;
+ }
+#endif
+
+ if (scst_cmd_is_expected_set(cmd)) {
+#ifdef CONFIG_SCST_USE_EXPECTED_VALUES
+# ifdef CONFIG_SCST_EXTRACHECKS
+ if (unlikely((cmd->data_direction != cmd->expected_data_direction) ||
+ (cmd->bufflen != cmd->expected_transfer_len))) {
+ TRACE(TRACE_MINOR, "Expected values don't match "
+ "decoded ones: data_direction %d, "
+ "expected_data_direction %d, "
+ "bufflen %d, expected_transfer_len %d",
+ cmd->data_direction,
+ cmd->expected_data_direction,
+ cmd->bufflen, cmd->expected_transfer_len);
+ PRINT_BUFF_FLAG(TRACE_MINOR, "Suspicious CDB",
+ cmd->cdb, cmd->cdb_len);
+ }
+# endif
+ cmd->data_direction = cmd->expected_data_direction;
+ cmd->bufflen = cmd->expected_transfer_len;
+#else
+ if (unlikely(cmd->data_direction !=
+ cmd->expected_data_direction)) {
+ if (((cmd->expected_data_direction != SCST_DATA_NONE) ||
+ (cmd->bufflen != 0)) &&
+ !scst_is_allowed_to_mismatch_cmd(cmd)) {
+ PRINT_ERROR("Expected data direction %d for "
+ "opcode 0x%02x (handler %s, target %s) "
+ "doesn't match decoded value %d",
+ cmd->expected_data_direction,
+ cmd->cdb[0], dev->handler->name,
+ cmd->tgtt->name, cmd->data_direction);
+ PRINT_BUFFER("Failed CDB", cmd->cdb,
+ cmd->cdb_len);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_message));
+ goto out_done;
+ }
+ }
+ if (unlikely(cmd->bufflen != cmd->expected_transfer_len)) {
+ TRACE(TRACE_MINOR, "Warning: expected "
+ "transfer length %d for opcode 0x%02x "
+ "(handler %s, target %s) doesn't match "
+ "decoded value %d. Faulty initiator "
+ "(e.g. VMware is known to be such) or "
+ "scst_scsi_op_table should be updated?",
+ cmd->expected_transfer_len, cmd->cdb[0],
+ dev->handler->name, cmd->tgtt->name,
+ cmd->bufflen);
+ PRINT_BUFF_FLAG(TRACE_MINOR, "Suspicious CDB",
+ cmd->cdb, cmd->cdb_len);
+ /* Needed, e.g., to get immediate iSCSI data */
+ cmd->bufflen = max(cmd->bufflen,
+ cmd->expected_transfer_len);
+ }
+#endif
+ }
+
+ if (unlikely(cmd->data_direction == SCST_DATA_UNKNOWN)) {
+ PRINT_ERROR("Unknown data direction. Opcode 0x%x, handler %s, "
+ "target %s", cmd->cdb[0], dev->handler->name,
+ cmd->tgtt->name);
+ PRINT_BUFFER("Failed CDB", cmd->cdb, cmd->cdb_len);
+ goto out_hw_error;
+ }
+
+set_res:
+ if (cmd->data_len == -1)
+ cmd->data_len = cmd->bufflen;
+
+ if (cmd->bufflen == 0) {
+ /*
+ * According to SPC bufflen 0 for data transfer commands isn't
+ * an error, so we need to fix the transfer direction.
+ */
+ cmd->data_direction = SCST_DATA_NONE;
+ }
+
+#ifdef CONFIG_SCST_EXTRACHECKS
+ switch (state) {
+ case SCST_CMD_STATE_PREPARE_SPACE:
+ case SCST_CMD_STATE_PRE_PARSE:
+ case SCST_CMD_STATE_DEV_PARSE:
+ case SCST_CMD_STATE_RDY_TO_XFER:
+ case SCST_CMD_STATE_TGT_PRE_EXEC:
+ case SCST_CMD_STATE_SEND_FOR_EXEC:
+ case SCST_CMD_STATE_LOCAL_EXEC:
+ case SCST_CMD_STATE_REAL_EXEC:
+ case SCST_CMD_STATE_PRE_DEV_DONE:
+ case SCST_CMD_STATE_DEV_DONE:
+ case SCST_CMD_STATE_PRE_XMIT_RESP:
+ case SCST_CMD_STATE_XMIT_RESP:
+ case SCST_CMD_STATE_FINISHED:
+ case SCST_CMD_STATE_FINISHED_INTERNAL:
+#endif
+ cmd->state = state;
+ res = SCST_CMD_STATE_RES_CONT_SAME;
+#ifdef CONFIG_SCST_EXTRACHECKS
+ break;
+
+ default:
+ if (state >= 0) {
+ PRINT_ERROR("Dev handler %s parse() returned "
+ "invalid cmd state %d (opcode %d)",
+ dev->handler->name, state, cmd->cdb[0]);
+ } else {
+ PRINT_ERROR("Dev handler %s parse() returned "
+ "error %d (opcode %d)", dev->handler->name,
+ state, cmd->cdb[0]);
+ }
+ goto out_hw_error;
+ }
+#endif
+
+ if (cmd->resp_data_len == -1) {
+ if (cmd->data_direction & SCST_DATA_READ)
+ cmd->resp_data_len = cmd->bufflen;
+ else
+ cmd->resp_data_len = 0;
+ }
+
+ /* We already completed (with an error) */
+ if (unlikely(cmd->completed))
+ goto out_done;
+
+out:
+ return res;
+
+out_hw_error:
+ /* dev_done() will be called as part of the regular cmd's finish */
+ scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+
+out_done:
+ scst_set_cmd_abnormal_done_state(cmd);
+ res = SCST_CMD_STATE_RES_CONT_SAME;
+ goto out;
+}
+
+static int scst_prepare_space(struct scst_cmd *cmd)
+{
+ int r = 0, res = SCST_CMD_STATE_RES_CONT_SAME;
+
+ if (cmd->data_direction == SCST_DATA_NONE)
+ goto done;
+
+ if (cmd->tgt_need_alloc_data_buf) {
+ int orig_bufflen = cmd->bufflen;
+
+ TRACE_MEM("Custom tgt data buf allocation requested (cmd %p)",
+ cmd);
+
+ scst_set_cur_start(cmd);
+ r = cmd->tgtt->alloc_data_buf(cmd);
+ scst_set_alloc_buf_time(cmd);
+
+ if (r > 0)
+ goto alloc;
+ else if (r == 0) {
+ if (unlikely(cmd->bufflen == 0)) {
+ /* See comment in scst_alloc_space() */
+ if (cmd->sg == NULL)
+ goto alloc;
+ }
+
+ cmd->tgt_data_buf_alloced = 1;
+
+ if (unlikely(orig_bufflen < cmd->bufflen)) {
+ PRINT_ERROR("Target driver allocated data "
+ "buffer (size %d), is less, than "
+ "required (size %d)", orig_bufflen,
+ cmd->bufflen);
+ goto out_error;
+ }
+ TRACE_MEM("tgt_data_buf_alloced (cmd %p)", cmd);
+ } else
+ goto check;
+ }
+
+alloc:
+ if (!cmd->tgt_data_buf_alloced && !cmd->dh_data_buf_alloced) {
+ r = scst_alloc_space(cmd);
+ } else if (cmd->dh_data_buf_alloced && !cmd->tgt_data_buf_alloced) {
+ TRACE_MEM("dh_data_buf_alloced set (cmd %p)", cmd);
+ r = 0;
+ } else if (cmd->tgt_data_buf_alloced && !cmd->dh_data_buf_alloced) {
+ TRACE_MEM("tgt_data_buf_alloced set (cmd %p)", cmd);
+ cmd->sg = cmd->tgt_sg;
+ cmd->sg_cnt = cmd->tgt_sg_cnt;
+ cmd->in_sg = cmd->tgt_in_sg;
+ cmd->in_sg_cnt = cmd->tgt_in_sg_cnt;
+ r = 0;
+ } else {
+ TRACE_MEM("Both *_data_buf_alloced set (cmd %p, sg %p, "
+ "sg_cnt %d, tgt_sg %p, tgt_sg_cnt %d)", cmd, cmd->sg,
+ cmd->sg_cnt, cmd->tgt_sg, cmd->tgt_sg_cnt);
+ r = 0;
+ }
+
+check:
+ if (r != 0) {
+ if (scst_cmd_atomic(cmd)) {
+ TRACE_MEM("%s", "Atomic memory allocation failed, "
+ "rescheduling to the thread");
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ goto out;
+ } else
+ goto out_no_space;
+ }
+
+done:
+ if (cmd->preprocessing_only)
+ cmd->state = SCST_CMD_STATE_PREPROCESSING_DONE;
+ else if (cmd->data_direction & SCST_DATA_WRITE)
+ cmd->state = SCST_CMD_STATE_RDY_TO_XFER;
+ else
+ cmd->state = SCST_CMD_STATE_TGT_PRE_EXEC;
+
+out:
+ return res;
+
+out_no_space:
+ TRACE(TRACE_OUT_OF_MEM, "Unable to allocate or build requested buffer "
+ "(size %d), sending BUSY or QUEUE FULL status", cmd->bufflen);
+ scst_set_busy(cmd);
+ scst_set_cmd_abnormal_done_state(cmd);
+ res = SCST_CMD_STATE_RES_CONT_SAME;
+ goto out;
+
+out_error:
+ scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+ scst_set_cmd_abnormal_done_state(cmd);
+ res = SCST_CMD_STATE_RES_CONT_SAME;
+ goto out;
+}
+
+static int scst_preprocessing_done(struct scst_cmd *cmd)
+{
+ int res;
+
+ EXTRACHECKS_BUG_ON(!cmd->preprocessing_only);
+
+ cmd->preprocessing_only = 0;
+
+ res = SCST_CMD_STATE_RES_CONT_NEXT;
+ cmd->state = SCST_CMD_STATE_PREPROCESSING_DONE_CALLED;
+
+ TRACE_DBG("Calling preprocessing_done(cmd %p)", cmd);
+ scst_set_cur_start(cmd);
+ cmd->tgtt->preprocessing_done(cmd);
+ TRACE_DBG("%s", "preprocessing_done() returned");
+ return res;
+}
+
+/**
+ * scst_restart_cmd() - restart execution of the command
+ * @cmd: SCST commands
+ * @status: completion status
+ * @pref_context: preferred command execition context
+ *
+ * Description:
+ * Notifies SCST that the driver finished its part of the command's
+ * preprocessing and it is ready for further processing.
+ *
+ * The second argument sets completion status
+ * (see SCST_PREPROCESS_STATUS_* constants for details)
+ *
+ * See also comment for scst_cmd_init_done() for the serialization
+ * requirements.
+ */
+void scst_restart_cmd(struct scst_cmd *cmd, int status,
+ enum scst_exec_context pref_context)
+{
+
+ scst_set_restart_waiting_time(cmd);
+
+ TRACE_DBG("Preferred context: %d", pref_context);
+ TRACE_DBG("tag=%llu, status=%#x",
+ (long long unsigned int)scst_cmd_get_tag(cmd),
+ status);
+
+#ifdef CONFIG_SCST_EXTRACHECKS
+ if ((in_irq() || irqs_disabled()) &&
+ ((pref_context == SCST_CONTEXT_DIRECT) ||
+ (pref_context == SCST_CONTEXT_DIRECT_ATOMIC))) {
+ PRINT_ERROR("Wrong context %d in IRQ from target %s, use "
+ "SCST_CONTEXT_THREAD instead", pref_context,
+ cmd->tgtt->name);
+ pref_context = SCST_CONTEXT_THREAD;
+ }
+#endif
+
+ switch (status) {
+ case SCST_PREPROCESS_STATUS_SUCCESS:
+ if (cmd->data_direction & SCST_DATA_WRITE)
+ cmd->state = SCST_CMD_STATE_RDY_TO_XFER;
+ else
+ cmd->state = SCST_CMD_STATE_TGT_PRE_EXEC;
+ if (cmd->set_sn_on_restart_cmd)
+ scst_cmd_set_sn(cmd);
+ /* Small context optimization */
+ if ((pref_context == SCST_CONTEXT_TASKLET) ||
+ (pref_context == SCST_CONTEXT_DIRECT_ATOMIC) ||
+ ((pref_context == SCST_CONTEXT_SAME) &&
+ scst_cmd_atomic(cmd))) {
+ if (cmd->data_direction & SCST_DATA_WRITE) {
+ if (!test_bit(SCST_TGT_DEV_AFTER_RESTART_WR_ATOMIC,
+ &cmd->tgt_dev->tgt_dev_flags))
+ pref_context = SCST_CONTEXT_THREAD;
+ } else {
+ if (!test_bit(SCST_TGT_DEV_AFTER_RESTART_OTH_ATOMIC,
+ &cmd->tgt_dev->tgt_dev_flags))
+ pref_context = SCST_CONTEXT_THREAD;
+ }
+ }
+ break;
+
+ case SCST_PREPROCESS_STATUS_ERROR_SENSE_SET:
+ scst_set_cmd_abnormal_done_state(cmd);
+ break;
+
+ case SCST_PREPROCESS_STATUS_ERROR_FATAL:
+ set_bit(SCST_CMD_NO_RESP, &cmd->cmd_flags);
+ /* go through */
+ case SCST_PREPROCESS_STATUS_ERROR:
+ if (cmd->sense != NULL)
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_hardw_error));
+ scst_set_cmd_abnormal_done_state(cmd);
+ break;
+
+ default:
+ PRINT_ERROR("%s() received unknown status %x", __func__,
+ status);
+ scst_set_cmd_abnormal_done_state(cmd);
+ break;
+ }
+
+ scst_process_redirect_cmd(cmd, pref_context, 1);
+ return;
+}
+EXPORT_SYMBOL(scst_restart_cmd);
+
+static int scst_rdy_to_xfer(struct scst_cmd *cmd)
+{
+ int res, rc;
+ struct scst_tgt_template *tgtt = cmd->tgtt;
+
+ if (unlikely(test_bit(SCST_CMD_ABORTED, &cmd->cmd_flags))) {
+ TRACE_MGMT_DBG("ABORTED set, aborting cmd %p", cmd);
+ goto out_dev_done;
+ }
+
+ if ((tgtt->rdy_to_xfer == NULL) || unlikely(cmd->internal)) {
+ cmd->state = SCST_CMD_STATE_TGT_PRE_EXEC;
+ res = SCST_CMD_STATE_RES_CONT_SAME;
+ goto out;
+ }
+
+ if (unlikely(!tgtt->rdy_to_xfer_atomic && scst_cmd_atomic(cmd))) {
+ /*
+ * It shouldn't be because of the SCST_TGT_DEV_AFTER_*
+ * optimization.
+ */
+ TRACE_DBG("Target driver %s rdy_to_xfer() needs thread "
+ "context, rescheduling", tgtt->name);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ goto out;
+ }
+
+ while (1) {
+ int finished_cmds = atomic_read(&cmd->tgt->finished_cmds);
+
+ res = SCST_CMD_STATE_RES_CONT_NEXT;
+ cmd->state = SCST_CMD_STATE_DATA_WAIT;
+
+ if (tgtt->on_hw_pending_cmd_timeout != NULL) {
+ struct scst_session *sess = cmd->sess;
+ cmd->hw_pending_start = jiffies;
+ cmd->cmd_hw_pending = 1;
+ if (!test_bit(SCST_SESS_HW_PENDING_WORK_SCHEDULED, &sess->sess_aflags)) {
+ TRACE_DBG("Sched HW pending work for sess %p "
+ "(max time %d)", sess,
+ tgtt->max_hw_pending_time);
+ set_bit(SCST_SESS_HW_PENDING_WORK_SCHEDULED,
+ &sess->sess_aflags);
+ schedule_delayed_work(&sess->hw_pending_work,
+ tgtt->max_hw_pending_time * HZ);
+ }
+ }
+
+ scst_set_cur_start(cmd);
+
+ TRACE_DBG("Calling rdy_to_xfer(%p)", cmd);
+#ifdef CONFIG_SCST_DEBUG_RETRY
+ if (((scst_random() % 100) == 75))
+ rc = SCST_TGT_RES_QUEUE_FULL;
+ else
+#endif
+ rc = tgtt->rdy_to_xfer(cmd);
+ TRACE_DBG("rdy_to_xfer() returned %d", rc);
+
+ if (likely(rc == SCST_TGT_RES_SUCCESS))
+ goto out;
+
+ scst_set_rdy_to_xfer_time(cmd);
+
+ cmd->cmd_hw_pending = 0;
+
+ /* Restore the previous state */
+ cmd->state = SCST_CMD_STATE_RDY_TO_XFER;
+
+ switch (rc) {
+ case SCST_TGT_RES_QUEUE_FULL:
+ if (scst_queue_retry_cmd(cmd, finished_cmds) == 0)
+ break;
+ else
+ continue;
+
+ case SCST_TGT_RES_NEED_THREAD_CTX:
+ TRACE_DBG("Target driver %s "
+ "rdy_to_xfer() requested thread "
+ "context, rescheduling", tgtt->name);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ break;
+
+ default:
+ goto out_error_rc;
+ }
+ break;
+ }
+
+out:
+ return res;
+
+out_error_rc:
+ if (rc == SCST_TGT_RES_FATAL_ERROR) {
+ PRINT_ERROR("Target driver %s rdy_to_xfer() returned "
+ "fatal error", tgtt->name);
+ } else {
+ PRINT_ERROR("Target driver %s rdy_to_xfer() returned invalid "
+ "value %d", tgtt->name, rc);
+ }
+ scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+
+out_dev_done:
+ scst_set_cmd_abnormal_done_state(cmd);
+ res = SCST_CMD_STATE_RES_CONT_SAME;
+ goto out;
+}
+
+/* No locks, but might be in IRQ */
+static void scst_process_redirect_cmd(struct scst_cmd *cmd,
+ enum scst_exec_context context, int check_retries)
+{
+ struct scst_tgt *tgt = cmd->tgt;
+ unsigned long flags;
+
+ TRACE_DBG("Context: %x", context);
+
+ if (context == SCST_CONTEXT_SAME)
+ context = scst_cmd_atomic(cmd) ? SCST_CONTEXT_DIRECT_ATOMIC :
+ SCST_CONTEXT_DIRECT;
+
+ switch (context) {
+ case SCST_CONTEXT_DIRECT_ATOMIC:
+ scst_process_active_cmd(cmd, true);
+ break;
+
+ case SCST_CONTEXT_DIRECT:
+ if (check_retries)
+ scst_check_retries(tgt);
+ scst_process_active_cmd(cmd, false);
+ break;
+
+ default:
+ PRINT_ERROR("Context %x is unknown, using the thread one",
+ context);
+ /* go through */
+ case SCST_CONTEXT_THREAD:
+ if (check_retries)
+ scst_check_retries(tgt);
+ spin_lock_irqsave(&cmd->cmd_threads->cmd_list_lock, flags);
+ TRACE_DBG("Adding cmd %p to active cmd list", cmd);
+ if (unlikely(cmd->queue_type == SCST_CMD_QUEUE_HEAD_OF_QUEUE))
+ list_add(&cmd->cmd_list_entry,
+ &cmd->cmd_threads->active_cmd_list);
+ else
+ list_add_tail(&cmd->cmd_list_entry,
+ &cmd->cmd_threads->active_cmd_list);
+ wake_up(&cmd->cmd_threads->cmd_list_waitQ);
+ spin_unlock_irqrestore(&cmd->cmd_threads->cmd_list_lock, flags);
+ break;
+
+ case SCST_CONTEXT_TASKLET:
+ if (check_retries)
+ scst_check_retries(tgt);
+ scst_schedule_tasklet(cmd);
+ break;
+ }
+ return;
+}
+
+/**
+ * scst_rx_data() - the command's data received
+ * @cmd: SCST commands
+ * @status: data receiving completion status
+ * @pref_context: preferred command execition context
+ *
+ * Description:
+ * Notifies SCST that the driver received all the necessary data
+ * and the command is ready for further processing.
+ *
+ * The second argument sets data receiving completion status
+ * (see SCST_RX_STATUS_* constants for details)
+ */
+void scst_rx_data(struct scst_cmd *cmd, int status,
+ enum scst_exec_context pref_context)
+{
+
+ scst_set_rdy_to_xfer_time(cmd);
+
+ TRACE_DBG("Preferred context: %d", pref_context);
+ TRACE(TRACE_SCSI, "cmd %p, status %#x", cmd, status);
+
+ cmd->cmd_hw_pending = 0;
+
+#ifdef CONFIG_SCST_EXTRACHECKS
+ if ((in_irq() || irqs_disabled()) &&
+ ((pref_context == SCST_CONTEXT_DIRECT) ||
+ (pref_context == SCST_CONTEXT_DIRECT_ATOMIC))) {
+ PRINT_ERROR("Wrong context %d in IRQ from target %s, use "
+ "SCST_CONTEXT_THREAD instead", pref_context,
+ cmd->tgtt->name);
+ pref_context = SCST_CONTEXT_THREAD;
+ }
+#endif
+
+ switch (status) {
+ case SCST_RX_STATUS_SUCCESS:
+#if defined(CONFIG_SCST_DEBUG) || defined(CONFIG_SCST_TRACING)
+ if (trace_flag & TRACE_RCV_BOT) {
+ int i;
+ struct scatterlist *sg;
+ if (cmd->in_sg != NULL)
+ sg = cmd->in_sg;
+ else if (cmd->tgt_in_sg != NULL)
+ sg = cmd->tgt_in_sg;
+ else if (cmd->tgt_sg != NULL)
+ sg = cmd->tgt_sg;
+ else
+ sg = cmd->sg;
+ if (sg != NULL) {
+ TRACE_RECV_BOT("RX data for cmd %p "
+ "(sg_cnt %d, sg %p, sg[0].page %p)",
+ cmd, cmd->tgt_sg_cnt, sg,
+ (void *)sg_page(&sg[0]));
+ for (i = 0; i < cmd->tgt_sg_cnt; ++i) {
+ PRINT_BUFF_FLAG(TRACE_RCV_BOT, "RX sg",
+ sg_virt(&sg[i]), sg[i].length);
+ }
+ }
+ }
+#endif
+ cmd->state = SCST_CMD_STATE_TGT_PRE_EXEC;
+
+ /* Small context optimization */
+ if ((pref_context == SCST_CONTEXT_TASKLET) ||
+ (pref_context == SCST_CONTEXT_DIRECT_ATOMIC) ||
+ ((pref_context == SCST_CONTEXT_SAME) &&
+ scst_cmd_atomic(cmd))) {
+ if (!test_bit(SCST_TGT_DEV_AFTER_RX_DATA_ATOMIC,
+ &cmd->tgt_dev->tgt_dev_flags))
+ pref_context = SCST_CONTEXT_THREAD;
+ }
+ break;
+
+ case SCST_RX_STATUS_ERROR_SENSE_SET:
+ scst_set_cmd_abnormal_done_state(cmd);
+ break;
+
+ case SCST_RX_STATUS_ERROR_FATAL:
+ set_bit(SCST_CMD_NO_RESP, &cmd->cmd_flags);
+ /* go through */
+ case SCST_RX_STATUS_ERROR:
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_hardw_error));
+ scst_set_cmd_abnormal_done_state(cmd);
+ break;
+
+ default:
+ PRINT_ERROR("scst_rx_data() received unknown status %x",
+ status);
+ scst_set_cmd_abnormal_done_state(cmd);
+ break;
+ }
+
+ scst_process_redirect_cmd(cmd, pref_context, 1);
+ return;
+}
+EXPORT_SYMBOL(scst_rx_data);
+
+static int scst_tgt_pre_exec(struct scst_cmd *cmd)
+{
+ int res = SCST_CMD_STATE_RES_CONT_SAME, rc;
+
+ cmd->state = SCST_CMD_STATE_SEND_FOR_EXEC;
+
+ if ((cmd->tgtt->pre_exec == NULL) || unlikely(cmd->internal))
+ goto out;
+
+ TRACE_DBG("Calling pre_exec(%p)", cmd);
+ scst_set_cur_start(cmd);
+ rc = cmd->tgtt->pre_exec(cmd);
+ scst_set_pre_exec_time(cmd);
+ TRACE_DBG("pre_exec() returned %d", rc);
+
+ if (unlikely(rc != SCST_PREPROCESS_STATUS_SUCCESS)) {
+ switch (rc) {
+ case SCST_PREPROCESS_STATUS_ERROR_SENSE_SET:
+ scst_set_cmd_abnormal_done_state(cmd);
+ break;
+ case SCST_PREPROCESS_STATUS_ERROR_FATAL:
+ set_bit(SCST_CMD_NO_RESP, &cmd->cmd_flags);
+ /* go through */
+ case SCST_PREPROCESS_STATUS_ERROR:
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_hardw_error));
+ scst_set_cmd_abnormal_done_state(cmd);
+ break;
+ case SCST_PREPROCESS_STATUS_NEED_THREAD:
+ TRACE_DBG("Target driver's %s pre_exec() requested "
+ "thread context, rescheduling",
+ cmd->tgtt->name);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ cmd->state = SCST_CMD_STATE_TGT_PRE_EXEC;
+ break;
+ default:
+ BUG();
+ break;
+ }
+ }
+
+out:
+ return res;
+}
+
+static void scst_do_cmd_done(struct scst_cmd *cmd, int result,
+ const uint8_t *rq_sense, int rq_sense_len, int resid)
+{
+
+ scst_set_exec_time(cmd);
+
+ cmd->status = result & 0xff;
+ cmd->msg_status = msg_byte(result);
+ cmd->host_status = host_byte(result);
+ cmd->driver_status = driver_byte(result);
+ if (unlikely(resid != 0)) {
+#ifdef CONFIG_SCST_EXTRACHECKS
+ if ((resid < 0) || (resid > cmd->resp_data_len)) {
+ PRINT_ERROR("Wrong resid %d (cmd->resp_data_len=%d, "
+ "op %x)", resid, cmd->resp_data_len,
+ cmd->cdb[0]);
+ } else
+#endif
+ scst_set_resp_data_len(cmd, cmd->resp_data_len - resid);
+ }
+
+ if (unlikely(cmd->status == SAM_STAT_CHECK_CONDITION)) {
+ /* We might have double reset UA here */
+ cmd->dbl_ua_orig_resp_data_len = cmd->resp_data_len;
+ cmd->dbl_ua_orig_data_direction = cmd->data_direction;
+
+ scst_alloc_set_sense(cmd, 1, rq_sense, rq_sense_len);
+ }
+
+ TRACE(TRACE_SCSI, "cmd %p, result=%x, cmd->status=%x, resid=%d, "
+ "cmd->msg_status=%x, cmd->host_status=%x, "
+ "cmd->driver_status=%x (cmd %p)", cmd, result, cmd->status, resid,
+ cmd->msg_status, cmd->host_status, cmd->driver_status, cmd);
+
+ cmd->completed = 1;
+ return;
+}
+
+/* For small context optimization */
+static inline enum scst_exec_context scst_optimize_post_exec_context(
+ struct scst_cmd *cmd, enum scst_exec_context context)
+{
+ if (((context == SCST_CONTEXT_SAME) && scst_cmd_atomic(cmd)) ||
+ (context == SCST_CONTEXT_TASKLET) ||
+ (context == SCST_CONTEXT_DIRECT_ATOMIC)) {
+ if (!test_bit(SCST_TGT_DEV_AFTER_EXEC_ATOMIC,
+ &cmd->tgt_dev->tgt_dev_flags))
+ context = SCST_CONTEXT_THREAD;
+ }
+ return context;
+}
+
+static void scst_cmd_done(void *data, char *sense, int result, int resid)
+{
+ struct scst_cmd *cmd;
+
+ cmd = (struct scst_cmd *)data;
+ if (cmd == NULL)
+ goto out;
+
+ scst_do_cmd_done(cmd, result, sense, SCSI_SENSE_BUFFERSIZE, resid);
+
+ cmd->state = SCST_CMD_STATE_PRE_DEV_DONE;
+
+ scst_process_redirect_cmd(cmd,
+ scst_optimize_post_exec_context(cmd, scst_estimate_context()), 0);
+
+out:
+ return;
+}
+
+static void scst_cmd_done_local(struct scst_cmd *cmd, int next_state,
+ enum scst_exec_context pref_context)
+{
+
+ scst_set_exec_time(cmd);
+
+ if (next_state == SCST_CMD_STATE_DEFAULT)
+ next_state = SCST_CMD_STATE_PRE_DEV_DONE;
+
+#if defined(CONFIG_SCST_DEBUG)
+ if (next_state == SCST_CMD_STATE_PRE_DEV_DONE) {
+ if ((trace_flag & TRACE_RCV_TOP) && (cmd->sg != NULL)) {
+ int i;
+ struct scatterlist *sg = cmd->sg;
+ TRACE_RECV_TOP("Exec'd %d S/G(s) at %p sg[0].page at "
+ "%p", cmd->sg_cnt, sg, (void *)sg_page(&sg[0]));
+ for (i = 0; i < cmd->sg_cnt; ++i) {
+ TRACE_BUFF_FLAG(TRACE_RCV_TOP,
+ "Exec'd sg", sg_virt(&sg[i]),
+ sg[i].length);
+ }
+ }
+ }
+#endif
+
+ cmd->state = next_state;
+
+#ifdef CONFIG_SCST_EXTRACHECKS
+ if ((next_state != SCST_CMD_STATE_PRE_DEV_DONE) &&
+ (next_state != SCST_CMD_STATE_PRE_XMIT_RESP) &&
+ (next_state != SCST_CMD_STATE_FINISHED) &&
+ (next_state != SCST_CMD_STATE_FINISHED_INTERNAL)) {
+ PRINT_ERROR("%s() received invalid cmd state %d (opcode %d)",
+ __func__, next_state, cmd->cdb[0]);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_hardw_error));
+ scst_set_cmd_abnormal_done_state(cmd);
+ }
+#endif
+ pref_context = scst_optimize_post_exec_context(cmd, pref_context);
+ scst_process_redirect_cmd(cmd, pref_context, 0);
+ return;
+}
+
+static int scst_report_luns_local(struct scst_cmd *cmd)
+{
+ int res = SCST_EXEC_COMPLETED, rc;
+ int dev_cnt = 0;
+ int buffer_size;
+ int i;
+ struct scst_tgt_dev *tgt_dev = NULL;
+ uint8_t *buffer;
+ int offs, overflow = 0;
+
+ if (scst_cmd_atomic(cmd)) {
+ res = SCST_EXEC_NEED_THREAD;
+ goto out;
+ }
+
+ rc = scst_check_local_events(cmd);
+ if (unlikely(rc != 0))
+ goto out_done;
+
+ cmd->status = 0;
+ cmd->msg_status = 0;
+ cmd->host_status = DID_OK;
+ cmd->driver_status = 0;
+
+ if ((cmd->cdb[2] != 0) && (cmd->cdb[2] != 2)) {
+ PRINT_ERROR("Unsupported SELECT REPORT value %x in REPORT "
+ "LUNS command", cmd->cdb[2]);
+ goto out_err;
+ }
+
+ buffer_size = scst_get_buf_first(cmd, &buffer);
+ if (unlikely(buffer_size == 0))
+ goto out_compl;
+ else if (unlikely(buffer_size < 0))
+ goto out_hw_err;
+
+ if (buffer_size < 16)
+ goto out_put_err;
+
+ memset(buffer, 0, buffer_size);
+ offs = 8;
+
+ /*
+ * cmd won't allow to suspend activities, so we can access
+ * sess->sess_tgt_dev_list_hash without any additional protection.
+ */
+ for (i = 0; i < TGT_DEV_HASH_SIZE; i++) {
+ struct list_head *sess_tgt_dev_list_head =
+ &cmd->sess->sess_tgt_dev_list_hash[i];
+ list_for_each_entry(tgt_dev, sess_tgt_dev_list_head,
+ sess_tgt_dev_list_entry) {
+ if (!overflow) {
+ if (offs >= buffer_size) {
+ scst_put_buf(cmd, buffer);
+ buffer_size = scst_get_buf_next(cmd,
+ &buffer);
+ if (buffer_size > 0) {
+ memset(buffer, 0, buffer_size);
+ offs = 0;
+ } else {
+ overflow = 1;
+ goto inc_dev_cnt;
+ }
+ }
+ if ((buffer_size - offs) < 8) {
+ PRINT_ERROR("Buffer allocated for "
+ "REPORT LUNS command doesn't "
+ "allow to fit 8 byte entry "
+ "(buffer_size=%d)",
+ buffer_size);
+ goto out_put_hw_err;
+ }
+ if ((cmd->sess->acg->addr_method == SCST_LUN_ADDR_METHOD_FLAT) &&
+ (tgt_dev->lun != 0)) {
+ buffer[offs] = (tgt_dev->lun >> 8) & 0x3f;
+ buffer[offs] = buffer[offs] | 0x40;
+ buffer[offs+1] = tgt_dev->lun & 0xff;
+ } else {
+ buffer[offs] = (tgt_dev->lun >> 8) & 0xff;
+ buffer[offs+1] = tgt_dev->lun & 0xff;
+ }
+ offs += 8;
+ }
+inc_dev_cnt:
+ dev_cnt++;
+ }
+ }
+ if (!overflow)
+ scst_put_buf(cmd, buffer);
+
+ /* Set the response header */
+ buffer_size = scst_get_buf_first(cmd, &buffer);
+ if (unlikely(buffer_size == 0))
+ goto out_compl;
+ else if (unlikely(buffer_size < 0))
+ goto out_hw_err;
+
+ dev_cnt *= 8;
+ buffer[0] = (dev_cnt >> 24) & 0xff;
+ buffer[1] = (dev_cnt >> 16) & 0xff;
+ buffer[2] = (dev_cnt >> 8) & 0xff;
+ buffer[3] = dev_cnt & 0xff;
+
+ scst_put_buf(cmd, buffer);
+
+ dev_cnt += 8;
+ if (dev_cnt < cmd->resp_data_len)
+ scst_set_resp_data_len(cmd, dev_cnt);
+
+out_compl:
+ cmd->completed = 1;
+
+ /* Clear left sense_reported_luns_data_changed UA, if any. */
+
+ /*
+ * cmd won't allow to suspend activities, so we can access
+ * sess->sess_tgt_dev_list_hash without any additional protection.
+ */
+ for (i = 0; i < TGT_DEV_HASH_SIZE; i++) {
+ struct list_head *sess_tgt_dev_list_head =
+ &cmd->sess->sess_tgt_dev_list_hash[i];
+
+ list_for_each_entry(tgt_dev, sess_tgt_dev_list_head,
+ sess_tgt_dev_list_entry) {
+ struct scst_tgt_dev_UA *ua;
+
+ spin_lock_bh(&tgt_dev->tgt_dev_lock);
+ list_for_each_entry(ua, &tgt_dev->UA_list,
+ UA_list_entry) {
+ if (scst_analyze_sense(ua->UA_sense_buffer,
+ ua->UA_valid_sense_len,
+ SCST_SENSE_ALL_VALID,
+ SCST_LOAD_SENSE(scst_sense_reported_luns_data_changed))) {
+ TRACE_MGMT_DBG("Freeing not needed "
+ "REPORTED LUNS DATA CHANGED UA "
+ "%p", ua);
+ list_del(&ua->UA_list_entry);
+ mempool_free(ua, scst_ua_mempool);
+ break;
+ }
+ }
+ spin_unlock_bh(&tgt_dev->tgt_dev_lock);
+ }
+ }
+
+out_done:
+ /* Report the result */
+ cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT, SCST_CONTEXT_SAME);
+
+out:
+ return res;
+
+out_put_err:
+ scst_put_buf(cmd, buffer);
+
+out_err:
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_field_in_cdb));
+ goto out_compl;
+
+out_put_hw_err:
+ scst_put_buf(cmd, buffer);
+
+out_hw_err:
+ scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+ goto out_compl;
+}
+
+static int scst_request_sense_local(struct scst_cmd *cmd)
+{
+ int res = SCST_EXEC_COMPLETED, rc;
+ struct scst_tgt_dev *tgt_dev = cmd->tgt_dev;
+ uint8_t *buffer;
+ int buffer_size = 0, sl = 0;
+
+ rc = scst_check_local_events(cmd);
+ if (unlikely(rc != 0))
+ goto out_done;
+
+ cmd->status = 0;
+ cmd->msg_status = 0;
+ cmd->host_status = DID_OK;
+ cmd->driver_status = 0;
+
+ spin_lock_bh(&tgt_dev->tgt_dev_lock);
+
+ if (tgt_dev->tgt_dev_valid_sense_len == 0)
+ goto out_not_completed;
+
+ TRACE(TRACE_SCSI, "%s: Returning stored sense", cmd->op_name);
+
+ buffer_size = scst_get_buf_first(cmd, &buffer);
+ if (unlikely(buffer_size == 0))
+ goto out_compl;
+ else if (unlikely(buffer_size < 0))
+ goto out_hw_err;
+
+ memset(buffer, 0, buffer_size);
+
+ if (((tgt_dev->tgt_dev_sense[0] == 0x70) ||
+ (tgt_dev->tgt_dev_sense[0] == 0x71)) && (cmd->cdb[1] & 1)) {
+ PRINT_WARNING("%s: Fixed format of the saved sense, but "
+ "descriptor format requested. Convertion will "
+ "truncated data", cmd->op_name);
+ PRINT_BUFFER("Original sense", tgt_dev->tgt_dev_sense,
+ tgt_dev->tgt_dev_valid_sense_len);
+
+ buffer_size = min(SCST_STANDARD_SENSE_LEN, buffer_size);
+ sl = scst_set_sense(buffer, buffer_size, true,
+ tgt_dev->tgt_dev_sense[2], tgt_dev->tgt_dev_sense[12],
+ tgt_dev->tgt_dev_sense[13]);
+ } else if (((tgt_dev->tgt_dev_sense[0] == 0x72) ||
+ (tgt_dev->tgt_dev_sense[0] == 0x73)) && !(cmd->cdb[1] & 1)) {
+ PRINT_WARNING("%s: Descriptor format of the "
+ "saved sense, but fixed format requested. Convertion "
+ "will truncated data", cmd->op_name);
+ PRINT_BUFFER("Original sense", tgt_dev->tgt_dev_sense,
+ tgt_dev->tgt_dev_valid_sense_len);
+
+ buffer_size = min(SCST_STANDARD_SENSE_LEN, buffer_size);
+ sl = scst_set_sense(buffer, buffer_size, false,
+ tgt_dev->tgt_dev_sense[1], tgt_dev->tgt_dev_sense[2],
+ tgt_dev->tgt_dev_sense[3]);
+ } else {
+ if (buffer_size >= tgt_dev->tgt_dev_valid_sense_len)
+ sl = tgt_dev->tgt_dev_valid_sense_len;
+ else {
+ sl = buffer_size;
+ PRINT_WARNING("%s: Being returned sense truncated to "
+ "size %d (needed %d)", cmd->op_name,
+ buffer_size, tgt_dev->tgt_dev_valid_sense_len);
+ }
+ memcpy(buffer, tgt_dev->tgt_dev_sense, sl);
+ }
+
+ scst_put_buf(cmd, buffer);
+
+ tgt_dev->tgt_dev_valid_sense_len = 0;
+
+ spin_unlock_bh(&tgt_dev->tgt_dev_lock);
+
+ scst_set_resp_data_len(cmd, sl);
+
+out_compl:
+ cmd->completed = 1;
+
+out_done:
+ /* Report the result */
+ cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT, SCST_CONTEXT_SAME);
+
+out:
+ return res;
+
+out_hw_err:
+ spin_unlock_bh(&tgt_dev->tgt_dev_lock);
+ scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+ goto out_compl;
+
+out_not_completed:
+ spin_unlock_bh(&tgt_dev->tgt_dev_lock);
+ res = SCST_EXEC_NOT_COMPLETED;
+ goto out;
+}
+
+static int scst_pre_select(struct scst_cmd *cmd)
+{
+ int res = SCST_EXEC_NOT_COMPLETED;
+
+ if (scst_cmd_atomic(cmd)) {
+ res = SCST_EXEC_NEED_THREAD;
+ goto out;
+ }
+
+ scst_block_dev_cmd(cmd, 1);
+
+ /* Check for local events will be done when cmd will be executed */
+
+out:
+ return res;
+}
+
+static int scst_reserve_local(struct scst_cmd *cmd)
+{
+ int res = SCST_EXEC_NOT_COMPLETED, rc;
+ struct scst_device *dev;
+ struct scst_tgt_dev *tgt_dev_tmp;
+
+ if (scst_cmd_atomic(cmd)) {
+ res = SCST_EXEC_NEED_THREAD;
+ goto out;
+ }
+
+ if ((cmd->cdb[0] == RESERVE_10) && (cmd->cdb[2] & SCST_RES_3RDPTY)) {
+ PRINT_ERROR("RESERVE_10: 3rdPty RESERVE not implemented "
+ "(lun=%lld)", (long long unsigned int)cmd->lun);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_invalid_field_in_cdb));
+ goto out_done;
+ }
+
+ dev = cmd->dev;
+
+ if (dev->tst == SCST_CONTR_MODE_ONE_TASK_SET)
+ scst_block_dev_cmd(cmd, 1);
+
+ rc = scst_check_local_events(cmd);
+ if (unlikely(rc != 0))
+ goto out_done;
+
+ spin_lock_bh(&dev->dev_lock);
+
+ if (test_bit(SCST_TGT_DEV_RESERVED, &cmd->tgt_dev->tgt_dev_flags)) {
+ spin_unlock_bh(&dev->dev_lock);
+ scst_set_cmd_error_status(cmd, SAM_STAT_RESERVATION_CONFLICT);
+ goto out_done;
+ }
+
+ list_for_each_entry(tgt_dev_tmp, &dev->dev_tgt_dev_list,
+ dev_tgt_dev_list_entry) {
+ if (cmd->tgt_dev != tgt_dev_tmp)
+ set_bit(SCST_TGT_DEV_RESERVED,
+ &tgt_dev_tmp->tgt_dev_flags);
+ }
+ dev->dev_reserved = 1;
+
+ spin_unlock_bh(&dev->dev_lock);
+
+out:
+ return res;
+
+out_done:
+ /* Report the result */
+ cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT, SCST_CONTEXT_SAME);
+ res = SCST_EXEC_COMPLETED;
+ goto out;
+}
+
+static int scst_release_local(struct scst_cmd *cmd)
+{
+ int res = SCST_EXEC_NOT_COMPLETED, rc;
+ struct scst_tgt_dev *tgt_dev_tmp;
+ struct scst_device *dev;
+
+ if (scst_cmd_atomic(cmd)) {
+ res = SCST_EXEC_NEED_THREAD;
+ goto out;
+ }
+
+ dev = cmd->dev;
+
+ if (dev->tst == SCST_CONTR_MODE_ONE_TASK_SET)
+ scst_block_dev_cmd(cmd, 1);
+
+ rc = scst_check_local_events(cmd);
+ if (unlikely(rc != 0))
+ goto out_done;
+
+ spin_lock_bh(&dev->dev_lock);
+
+ /*
+ * The device could be RELEASED behind us, if RESERVING session
+ * is closed (see scst_free_tgt_dev()), but this actually doesn't
+ * matter, so use lock and no retest for DEV_RESERVED bits again
+ */
+ if (test_bit(SCST_TGT_DEV_RESERVED, &cmd->tgt_dev->tgt_dev_flags)) {
+ res = SCST_EXEC_COMPLETED;
+ cmd->status = 0;
+ cmd->msg_status = 0;
+ cmd->host_status = DID_OK;
+ cmd->driver_status = 0;
+ cmd->completed = 1;
+ } else {
+ list_for_each_entry(tgt_dev_tmp,
+ &dev->dev_tgt_dev_list,
+ dev_tgt_dev_list_entry) {
+ clear_bit(SCST_TGT_DEV_RESERVED,
+ &tgt_dev_tmp->tgt_dev_flags);
+ }
+ dev->dev_reserved = 0;
+ }
+
+ spin_unlock_bh(&dev->dev_lock);
+
+ if (res == SCST_EXEC_COMPLETED)
+ goto out_done;
+
+out:
+ return res;
+
+out_done:
+ res = SCST_EXEC_COMPLETED;
+ /* Report the result */
+ cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT, SCST_CONTEXT_SAME);
+ goto out;
+}
+
+/**
+ * scst_check_local_events() - check if there are any local SCSI events
+ *
+ * Description:
+ * Checks if the command can be executed or there are local events,
+ * like reservatons, pending UAs, etc. Returns < 0 if command must be
+ * aborted, > 0 if there is an event and command should be immediately
+ * completed, or 0 otherwise.
+ *
+ * !! Dev handlers implementing exec() callback must call this function there
+ * !! just before the actual command's execution!
+ *
+ * On call no locks, no IRQ or IRQ-disabled context allowed.
+ */
+int scst_check_local_events(struct scst_cmd *cmd)
+{
+ int res, rc;
+ struct scst_tgt_dev *tgt_dev = cmd->tgt_dev;
+ struct scst_device *dev = cmd->dev;
+
+ /*
+ * There's no race here, because we need to trace commands sent
+ * *after* dev_double_ua_possible flag was set.
+ */
+ if (unlikely(dev->dev_double_ua_possible))
+ cmd->double_ua_possible = 1;
+
+ if (unlikely(test_bit(SCST_CMD_ABORTED, &cmd->cmd_flags))) {
+ TRACE_MGMT_DBG("ABORTED set, aborting cmd %p", cmd);
+ goto out_uncomplete;
+ }
+
+ /* Reserve check before Unit Attention */
+ if (unlikely(test_bit(SCST_TGT_DEV_RESERVED,
+ &tgt_dev->tgt_dev_flags))) {
+ if ((cmd->op_flags & SCST_REG_RESERVE_ALLOWED) == 0) {
+ scst_set_cmd_error_status(cmd,
+ SAM_STAT_RESERVATION_CONFLICT);
+ goto out_complete;
+ }
+ }
+
+ /* If we had internal bus reset, set the command error unit attention */
+ if ((dev->scsi_dev != NULL) &&
+ unlikely(dev->scsi_dev->was_reset)) {
+ if (scst_is_ua_command(cmd)) {
+ int done = 0;
+ /*
+ * Prevent more than 1 cmd to be triggered by
+ * was_reset.
+ */
+ spin_lock_bh(&dev->dev_lock);
+ if (dev->scsi_dev->was_reset) {
+ TRACE(TRACE_MGMT, "was_reset is %d", 1);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_reset_UA));
+ /*
+ * It looks like it is safe to clear was_reset
+ * here.
+ */
+ dev->scsi_dev->was_reset = 0;
+ done = 1;
+ }
+ spin_unlock_bh(&dev->dev_lock);
+
+ if (done)
+ goto out_complete;
+ }
+ }
+
+ if (unlikely(test_bit(SCST_TGT_DEV_UA_PENDING,
+ &cmd->tgt_dev->tgt_dev_flags))) {
+ if (scst_is_ua_command(cmd)) {
+ rc = scst_set_pending_UA(cmd);
+ if (rc == 0)
+ goto out_complete;
+ }
+ }
+
+ res = 0;
+
+out:
+ return res;
+
+out_complete:
+ res = 1;
+ BUG_ON(!cmd->completed);
+ goto out;
+
+out_uncomplete:
+ res = -1;
+ goto out;
+}
+EXPORT_SYMBOL_GPL(scst_check_local_events);
+
+/* No locks */
+void scst_inc_expected_sn(struct scst_tgt_dev *tgt_dev, atomic_t *slot)
+{
+ if (slot == NULL)
+ goto inc;
+
+ /* Optimized for lockless fast path */
+
+ TRACE_SN("Slot %zd, *cur_sn_slot %d", slot - tgt_dev->sn_slots,
+ atomic_read(slot));
+
+ if (!atomic_dec_and_test(slot))
+ goto out;
+
+ TRACE_SN("Slot is 0 (num_free_sn_slots=%d)",
+ tgt_dev->num_free_sn_slots);
+ if (tgt_dev->num_free_sn_slots < (int)ARRAY_SIZE(tgt_dev->sn_slots)-1) {
+ spin_lock_irq(&tgt_dev->sn_lock);
+ if (likely(tgt_dev->num_free_sn_slots < (int)ARRAY_SIZE(tgt_dev->sn_slots)-1)) {
+ if (tgt_dev->num_free_sn_slots < 0)
+ tgt_dev->cur_sn_slot = slot;
+ /*
+ * To be in-sync with SIMPLE case in scst_cmd_set_sn()
+ */
+ smp_mb();
+ tgt_dev->num_free_sn_slots++;
+ TRACE_SN("Incremented num_free_sn_slots (%d)",
+ tgt_dev->num_free_sn_slots);
+
+ }
+ spin_unlock_irq(&tgt_dev->sn_lock);
+ }
+
+inc:
+ /*
+ * No protection of expected_sn is needed, because only one thread
+ * at time can be here (serialized by sn). Also it is supposed that
+ * there could not be half-incremented halves.
+ */
+ tgt_dev->expected_sn++;
+ /*
+ * Write must be before def_cmd_count read to be in sync. with
+ * scst_post_exec_sn(). See comment in scst_send_for_exec().
+ */
+ smp_mb();
+ TRACE_SN("Next expected_sn: %d", tgt_dev->expected_sn);
+
+out:
+ return;
+}
+
+/* No locks */
+static struct scst_cmd *scst_post_exec_sn(struct scst_cmd *cmd,
+ bool make_active)
+{
+ /* For HQ commands SN is not set */
+ bool inc_expected_sn = !cmd->inc_expected_sn_on_done &&
+ cmd->sn_set && !cmd->retry;
+ struct scst_tgt_dev *tgt_dev = cmd->tgt_dev;
+ struct scst_cmd *res;
+
+ if (inc_expected_sn)
+ scst_inc_expected_sn(tgt_dev, cmd->sn_slot);
+
+ if (make_active) {
+ scst_make_deferred_commands_active(tgt_dev);
+ res = NULL;
+ } else
+ res = scst_check_deferred_commands(tgt_dev);
+ return res;
+}
+
+/* cmd must be additionally referenced to not die inside */
+static int scst_do_real_exec(struct scst_cmd *cmd)
+{
+ int res = SCST_EXEC_NOT_COMPLETED;
+ int rc;
+ bool atomic = scst_cmd_atomic(cmd);
+ struct scst_device *dev = cmd->dev;
+ struct scst_dev_type *handler = dev->handler;
+ struct io_context *old_ctx = NULL;
+ bool ctx_changed = false;
+
+ if (!atomic)
+ ctx_changed = scst_set_io_context(cmd, &old_ctx);
+
+ cmd->state = SCST_CMD_STATE_REAL_EXECUTING;
+
+ if (handler->exec) {
+ if (unlikely(!dev->handler->exec_atomic && atomic)) {
+ /*
+ * It shouldn't be because of the SCST_TGT_DEV_AFTER_*
+ * optimization.
+ */
+ TRACE_DBG("Dev handler %s exec() needs thread "
+ "context, rescheduling", dev->handler->name);
+ res = SCST_EXEC_NEED_THREAD;
+ goto out_restore;
+ }
+
+ TRACE_DBG("Calling dev handler %s exec(%p)",
+ handler->name, cmd);
+ TRACE_BUFF_FLAG(TRACE_SND_TOP, "Execing: ", cmd->cdb,
+ cmd->cdb_len);
+ scst_set_cur_start(cmd);
+ res = handler->exec(cmd);
+ TRACE_DBG("Dev handler %s exec() returned %d",
+ handler->name, res);
+
+ if (res == SCST_EXEC_COMPLETED)
+ goto out_complete;
+ else if (res == SCST_EXEC_NEED_THREAD)
+ goto out_restore;
+
+ scst_set_exec_time(cmd);
+
+ BUG_ON(res != SCST_EXEC_NOT_COMPLETED);
+ }
+
+ TRACE_DBG("Sending cmd %p to SCSI mid-level", cmd);
+
+ if (unlikely(dev->scsi_dev == NULL)) {
+ PRINT_ERROR("Command for virtual device must be "
+ "processed by device handler (LUN %lld)!",
+ (long long unsigned int)cmd->lun);
+ goto out_error;
+ }
+
+ res = scst_check_local_events(cmd);
+ if (unlikely(res != 0))
+ goto out_done;
+
+#ifndef CONFIG_SCST_ALLOW_PASSTHROUGH_IO_SUBMIT_IN_SIRQ
+ if (unlikely(atomic)) {
+ TRACE_DBG("Pass-through exec() can not be called in atomic "
+ "context, rescheduling to the thread (handler %s)",
+ handler->name);
+ res = SCST_EXEC_NEED_THREAD;
+ goto out_restore;
+ }
+#endif
+
+ scst_set_cur_start(cmd);
+
+ rc = scst_scsi_exec_async(cmd, scst_cmd_done);
+ if (unlikely(rc != 0)) {
+ if (atomic) {
+ res = SCST_EXEC_NEED_THREAD;
+ goto out_restore;
+ } else {
+ PRINT_ERROR("scst pass-through exec failed: %x", rc);
+ goto out_error;
+ }
+ }
+
+out_complete:
+ res = SCST_EXEC_COMPLETED;
+
+out_reset_ctx:
+ if (ctx_changed)
+ scst_reset_io_context(cmd->tgt_dev, old_ctx);
+ return res;
+
+out_restore:
+ scst_set_exec_time(cmd);
+ /* Restore the state */
+ cmd->state = SCST_CMD_STATE_REAL_EXEC;
+ goto out_reset_ctx;
+
+out_error:
+ scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+ goto out_done;
+
+out_done:
+ res = SCST_EXEC_COMPLETED;
+ /* Report the result */
+ cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT, SCST_CONTEXT_SAME);
+ goto out_complete;
+}
+
+static inline int scst_real_exec(struct scst_cmd *cmd)
+{
+ int res;
+
+ BUILD_BUG_ON(SCST_CMD_STATE_RES_CONT_SAME != SCST_EXEC_NOT_COMPLETED);
+ BUILD_BUG_ON(SCST_CMD_STATE_RES_CONT_NEXT != SCST_EXEC_COMPLETED);
+ BUILD_BUG_ON(SCST_CMD_STATE_RES_NEED_THREAD != SCST_EXEC_NEED_THREAD);
+
+ __scst_cmd_get(cmd);
+
+ res = scst_do_real_exec(cmd);
+
+ if (likely(res == SCST_EXEC_COMPLETED)) {
+ scst_post_exec_sn(cmd, true);
+ if (cmd->dev->scsi_dev != NULL)
+ generic_unplug_device(
+ cmd->dev->scsi_dev->request_queue);
+ } else
+ BUG_ON(res != SCST_EXEC_NEED_THREAD);
+
+ __scst_cmd_put(cmd);
+
+ /* SCST_EXEC_* match SCST_CMD_STATE_RES_* */
+ return res;
+}
+
+static int scst_do_local_exec(struct scst_cmd *cmd)
+{
+ int res;
+ struct scst_tgt_dev *tgt_dev = cmd->tgt_dev;
+
+ /* Check READ_ONLY device status */
+ if ((cmd->op_flags & SCST_WRITE_MEDIUM) &&
+ (tgt_dev->acg_dev->rd_only || cmd->dev->swp ||
+ cmd->dev->rd_only)) {
+ PRINT_WARNING("Attempt of write access to read-only device: "
+ "initiator %s, LUN %lld, op %x",
+ cmd->sess->initiator_name, cmd->lun, cmd->cdb[0]);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_data_protect));
+ goto out_done;
+ }
+
+ if (!scst_is_cmd_local(cmd)) {
+ res = SCST_EXEC_NOT_COMPLETED;
+ goto out;
+ }
+
+ switch (cmd->cdb[0]) {
+ case MODE_SELECT:
+ case MODE_SELECT_10:
+ case LOG_SELECT:
+ res = scst_pre_select(cmd);
+ break;
+ case RESERVE:
+ case RESERVE_10:
+ res = scst_reserve_local(cmd);
+ break;
+ case RELEASE:
+ case RELEASE_10:
+ res = scst_release_local(cmd);
+ break;
+ case REPORT_LUNS:
+ res = scst_report_luns_local(cmd);
+ break;
+ case REQUEST_SENSE:
+ res = scst_request_sense_local(cmd);
+ break;
+ default:
+ res = SCST_EXEC_NOT_COMPLETED;
+ break;
+ }
+
+out:
+ return res;
+
+out_done:
+ /* Report the result */
+ cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT, SCST_CONTEXT_SAME);
+ res = SCST_EXEC_COMPLETED;
+ goto out;
+}
+
+static int scst_local_exec(struct scst_cmd *cmd)
+{
+ int res;
+
+ BUILD_BUG_ON(SCST_CMD_STATE_RES_CONT_SAME != SCST_EXEC_NOT_COMPLETED);
+ BUILD_BUG_ON(SCST_CMD_STATE_RES_CONT_NEXT != SCST_EXEC_COMPLETED);
+ BUILD_BUG_ON(SCST_CMD_STATE_RES_NEED_THREAD != SCST_EXEC_NEED_THREAD);
+
+ __scst_cmd_get(cmd);
+
+ res = scst_do_local_exec(cmd);
+ if (likely(res == SCST_EXEC_NOT_COMPLETED))
+ cmd->state = SCST_CMD_STATE_REAL_EXEC;
+ else if (res == SCST_EXEC_COMPLETED)
+ scst_post_exec_sn(cmd, true);
+ else
+ BUG_ON(res != SCST_EXEC_NEED_THREAD);
+
+ __scst_cmd_put(cmd);
+
+ /* SCST_EXEC_* match SCST_CMD_STATE_RES_* */
+ return res;
+}
+
+static int scst_exec(struct scst_cmd **active_cmd)
+{
+ struct scst_cmd *cmd = *active_cmd;
+ struct scst_cmd *ref_cmd;
+ struct scst_device *dev = cmd->dev;
+ int res = SCST_CMD_STATE_RES_CONT_NEXT, count;
+
+ if (unlikely(scst_inc_on_dev_cmd(cmd) != 0))
+ goto out;
+
+ /* To protect tgt_dev */
+ ref_cmd = cmd;
+ __scst_cmd_get(ref_cmd);
+
+ count = 0;
+ while (1) {
+ int rc;
+
+ cmd->sent_for_exec = 1;
+ /*
+ * To sync with scst_abort_cmd(). The above assignment must
+ * be before SCST_CMD_ABORTED test, done later in
+ * scst_check_local_events(). It's far from here, so the order
+ * is virtually guaranteed, but let's have it just in case.
+ */
+ smp_mb();
+
+ cmd->scst_cmd_done = scst_cmd_done_local;
+ cmd->state = SCST_CMD_STATE_LOCAL_EXEC;
+
+ rc = scst_do_local_exec(cmd);
+ if (likely(rc == SCST_EXEC_NOT_COMPLETED))
+ /* Nothing to do */;
+ else if (rc == SCST_EXEC_NEED_THREAD) {
+ TRACE_DBG("%s", "scst_do_local_exec() requested "
+ "thread context, rescheduling");
+ scst_dec_on_dev_cmd(cmd);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ break;
+ } else {
+ BUG_ON(rc != SCST_EXEC_COMPLETED);
+ goto done;
+ }
+
+ cmd->state = SCST_CMD_STATE_REAL_EXEC;
+
+ rc = scst_do_real_exec(cmd);
+ if (likely(rc == SCST_EXEC_COMPLETED))
+ /* Nothing to do */;
+ else if (rc == SCST_EXEC_NEED_THREAD) {
+ TRACE_DBG("scst_real_exec() requested thread "
+ "context, rescheduling (cmd %p)", cmd);
+ scst_dec_on_dev_cmd(cmd);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ break;
+ } else
+ BUG();
+
+done:
+ count++;
+
+ cmd = scst_post_exec_sn(cmd, false);
+ if (cmd == NULL)
+ break;
+
+ if (unlikely(scst_inc_on_dev_cmd(cmd) != 0))
+ break;
+
+ __scst_cmd_put(ref_cmd);
+ ref_cmd = cmd;
+ __scst_cmd_get(ref_cmd);
+ }
+
+ *active_cmd = cmd;
+
+ if (count == 0)
+ goto out_put;
+
+ if (dev->scsi_dev != NULL)
+ generic_unplug_device(dev->scsi_dev->request_queue);
+
+out_put:
+ __scst_cmd_put(ref_cmd);
+ /* !! At this point sess, dev and tgt_dev can be already freed !! */
+
+out:
+ return res;
+}
+
+static int scst_send_for_exec(struct scst_cmd **active_cmd)
+{
+ int res;
+ struct scst_cmd *cmd = *active_cmd;
+ struct scst_tgt_dev *tgt_dev = cmd->tgt_dev;
+ typeof(tgt_dev->expected_sn) expected_sn;
+
+ if (unlikely(cmd->internal))
+ goto exec;
+
+ if (unlikely(cmd->queue_type == SCST_CMD_QUEUE_HEAD_OF_QUEUE))
+ goto exec;
+
+ BUG_ON(!cmd->sn_set);
+
+ expected_sn = tgt_dev->expected_sn;
+ /* Optimized for lockless fast path */
+ if ((cmd->sn != expected_sn) || (tgt_dev->hq_cmd_count > 0)) {
+ spin_lock_irq(&tgt_dev->sn_lock);
+
+ tgt_dev->def_cmd_count++;
+ /*
+ * Memory barrier is needed here to implement lockless fast
+ * path. We need the exact order of read and write between
+ * def_cmd_count and expected_sn. Otherwise, we can miss case,
+ * when expected_sn was changed to be equal to cmd->sn while
+ * we are queuing cmd the deferred list after the expected_sn
+ * below. It will lead to a forever stuck command. But with
+ * the barrier in such case __scst_check_deferred_commands()
+ * will be called and it will take sn_lock, so we will be
+ * synchronized.
+ */
+ smp_mb();
+
+ expected_sn = tgt_dev->expected_sn;
+ if ((cmd->sn != expected_sn) || (tgt_dev->hq_cmd_count > 0)) {
+ if (unlikely(test_bit(SCST_CMD_ABORTED,
+ &cmd->cmd_flags))) {
+ /* Necessary to allow aborting out of sn cmds */
+ TRACE_MGMT_DBG("Aborting out of sn cmd %p "
+ "(tag %llu, sn %u)", cmd,
+ (long long unsigned)cmd->tag, cmd->sn);
+ tgt_dev->def_cmd_count--;
+ scst_set_cmd_abnormal_done_state(cmd);
+ res = SCST_CMD_STATE_RES_CONT_SAME;
+ } else {
+ TRACE_SN("Deferring cmd %p (sn=%d, set %d, "
+ "expected_sn=%d)", cmd, cmd->sn,
+ cmd->sn_set, expected_sn);
+ list_add_tail(&cmd->sn_cmd_list_entry,
+ &tgt_dev->deferred_cmd_list);
+ res = SCST_CMD_STATE_RES_CONT_NEXT;
+ }
+ spin_unlock_irq(&tgt_dev->sn_lock);
+ goto out;
+ } else {
+ TRACE_SN("Somebody incremented expected_sn %d, "
+ "continuing", expected_sn);
+ tgt_dev->def_cmd_count--;
+ spin_unlock_irq(&tgt_dev->sn_lock);
+ }
+ }
+
+exec:
+ res = scst_exec(active_cmd);
+
+out:
+ return res;
+}
+
+/* No locks supposed to be held */
+static int scst_check_sense(struct scst_cmd *cmd)
+{
+ int res = 0;
+ struct scst_device *dev = cmd->dev;
+
+ if (unlikely(cmd->ua_ignore))
+ goto out;
+
+ /* If we had internal bus reset behind us, set the command error UA */
+ if ((dev->scsi_dev != NULL) &&
+ unlikely(cmd->host_status == DID_RESET) &&
+ scst_is_ua_command(cmd)) {
+ TRACE(TRACE_MGMT, "DID_RESET: was_reset=%d host_status=%x",
+ dev->scsi_dev->was_reset, cmd->host_status);
+ scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_reset_UA));
+ /* It looks like it is safe to clear was_reset here */
+ dev->scsi_dev->was_reset = 0;
+ }
+
+ if (unlikely(cmd->status == SAM_STAT_CHECK_CONDITION) &&
+ SCST_SENSE_VALID(cmd->sense)) {
+ PRINT_BUFF_FLAG(TRACE_SCSI, "Sense", cmd->sense,
+ cmd->sense_valid_len);
+
+ /* Check Unit Attention Sense Key */
+ if (scst_is_ua_sense(cmd->sense, cmd->sense_valid_len)) {
+ if (scst_analyze_sense(cmd->sense, cmd->sense_valid_len,
+ SCST_SENSE_ASC_VALID,
+ 0, SCST_SENSE_ASC_UA_RESET, 0)) {
+ if (cmd->double_ua_possible) {
+ TRACE_MGMT_DBG("Double UA "
+ "detected for device %p", dev);
+ TRACE_MGMT_DBG("Retrying cmd"
+ " %p (tag %llu)", cmd,
+ (long long unsigned)cmd->tag);
+
+ cmd->status = 0;
+ cmd->msg_status = 0;
+ cmd->host_status = DID_OK;
+ cmd->driver_status = 0;
+ cmd->completed = 0;
+
+ mempool_free(cmd->sense,
+ scst_sense_mempool);
+ cmd->sense = NULL;
+
+ scst_check_restore_sg_buff(cmd);
+
+ BUG_ON(cmd->dbl_ua_orig_resp_data_len < 0);
+ cmd->data_direction =
+ cmd->dbl_ua_orig_data_direction;
+ cmd->resp_data_len =
+ cmd->dbl_ua_orig_resp_data_len;
+
+ cmd->state = SCST_CMD_STATE_REAL_EXEC;
+ cmd->retry = 1;
+ res = 1;
+ goto out;
+ }
+ }
+ scst_dev_check_set_UA(dev, cmd, cmd->sense,
+ cmd->sense_valid_len);
+ }
+ }
+
+ if (unlikely(cmd->double_ua_possible)) {
+ if (scst_is_ua_command(cmd)) {
+ TRACE_MGMT_DBG("Clearing dbl_ua_possible flag (dev %p, "
+ "cmd %p)", dev, cmd);
+ /*
+ * Lock used to protect other flags in the bitfield
+ * (just in case, actually). Those flags can't be
+ * changed in parallel, because the device is
+ * serialized.
+ */
+ spin_lock_bh(&dev->dev_lock);
+ dev->dev_double_ua_possible = 0;
+ spin_unlock_bh(&dev->dev_lock);
+ }
+ }
+
+out:
+ return res;
+}
+
+static int scst_check_auto_sense(struct scst_cmd *cmd)
+{
+ int res = 0;
+
+ if (unlikely(cmd->status == SAM_STAT_CHECK_CONDITION) &&
+ (!SCST_SENSE_VALID(cmd->sense) ||
+ SCST_NO_SENSE(cmd->sense))) {
+ TRACE(TRACE_SCSI|TRACE_MINOR_AND_MGMT_DBG, "CHECK_CONDITION, "
+ "but no sense: cmd->status=%x, cmd->msg_status=%x, "
+ "cmd->host_status=%x, cmd->driver_status=%x (cmd %p)",
+ cmd->status, cmd->msg_status, cmd->host_status,
+ cmd->driver_status, cmd);
+ res = 1;
+ } else if (unlikely(cmd->host_status)) {
+ if ((cmd->host_status == DID_REQUEUE) ||
+ (cmd->host_status == DID_IMM_RETRY) ||
+ (cmd->host_status == DID_SOFT_ERROR) ||
+ (cmd->host_status == DID_ABORT)) {
+ scst_set_busy(cmd);
+ } else {
+ TRACE(TRACE_SCSI|TRACE_MINOR_AND_MGMT_DBG, "Host "
+ "status %x received, returning HARDWARE ERROR "
+ "instead (cmd %p)", cmd->host_status, cmd);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_hardw_error));
+ }
+ }
+ return res;
+}
+
+static int scst_pre_dev_done(struct scst_cmd *cmd)
+{
+ int res = SCST_CMD_STATE_RES_CONT_SAME, rc;
+
+ if (unlikely(scst_check_auto_sense(cmd))) {
+ PRINT_INFO("Command finished with CHECK CONDITION, but "
+ "without sense data (opcode 0x%x), issuing "
+ "REQUEST SENSE", cmd->cdb[0]);
+ rc = scst_prepare_request_sense(cmd);
+ if (rc == 0)
+ res = SCST_CMD_STATE_RES_CONT_NEXT;
+ else {
+ PRINT_ERROR("%s", "Unable to issue REQUEST SENSE, "
+ "returning HARDWARE ERROR");
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_hardw_error));
+ }
+ goto out;
+ } else if (unlikely(scst_check_sense(cmd)))
+ goto out;
+
+ if (likely(scsi_status_is_good(cmd->status))) {
+ unsigned char type = cmd->dev->type;
+ if (unlikely((cmd->cdb[0] == MODE_SENSE ||
+ cmd->cdb[0] == MODE_SENSE_10)) &&
+ (cmd->tgt_dev->acg_dev->rd_only || cmd->dev->swp ||
+ cmd->dev->rd_only) &&
+ (type == TYPE_DISK ||
+ type == TYPE_WORM ||
+ type == TYPE_MOD ||
+ type == TYPE_TAPE)) {
+ int32_t length;
+ uint8_t *address;
+ bool err = false;
+
+ length = scst_get_buf_first(cmd, &address);
+ if (length < 0) {
+ PRINT_ERROR("%s", "Unable to get "
+ "MODE_SENSE buffer");
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(
+ scst_sense_hardw_error));
+ err = true;
+ } else if (length > 2 && cmd->cdb[0] == MODE_SENSE)
+ address[2] |= 0x80; /* Write Protect*/
+ else if (length > 3 && cmd->cdb[0] == MODE_SENSE_10)
+ address[3] |= 0x80; /* Write Protect*/
+ scst_put_buf(cmd, address);
+
+ if (err)
+ goto out;
+ }
+
+ /*
+ * Check and clear NormACA option for the device, if necessary,
+ * since we don't support ACA
+ */
+ if (unlikely((cmd->cdb[0] == INQUIRY)) &&
+ /* Std INQUIRY data (no EVPD) */
+ !(cmd->cdb[1] & SCST_INQ_EVPD) &&
+ (cmd->resp_data_len > SCST_INQ_BYTE3)) {
+ uint8_t *buffer;
+ int buflen;
+ bool err = false;
+
+ /* ToDo: all pages ?? */
+ buflen = scst_get_buf_first(cmd, &buffer);
+ if (buflen > SCST_INQ_BYTE3) {
+#ifdef CONFIG_SCST_EXTRACHECKS
+ if (buffer[SCST_INQ_BYTE3] & SCST_INQ_NORMACA_BIT) {
+ PRINT_INFO("NormACA set for device: "
+ "lun=%lld, type 0x%02x. Clear it, "
+ "since it's unsupported.",
+ (long long unsigned int)cmd->lun,
+ buffer[0]);
+ }
+#endif
+ buffer[SCST_INQ_BYTE3] &= ~SCST_INQ_NORMACA_BIT;
+ } else if (buflen != 0) {
+ PRINT_ERROR("%s", "Unable to get INQUIRY "
+ "buffer");
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_hardw_error));
+ err = true;
+ }
+ if (buflen > 0)
+ scst_put_buf(cmd, buffer);
+
+ if (err)
+ goto out;
+ }
+
+ if (unlikely((cmd->cdb[0] == MODE_SELECT) ||
+ (cmd->cdb[0] == MODE_SELECT_10) ||
+ (cmd->cdb[0] == LOG_SELECT))) {
+ TRACE(TRACE_SCSI,
+ "MODE/LOG SELECT succeeded (LUN %lld)",
+ (long long unsigned int)cmd->lun);
+ cmd->state = SCST_CMD_STATE_MODE_SELECT_CHECKS;
+ goto out;
+ }
+ } else {
+ TRACE(TRACE_SCSI, "cmd %p not succeeded with status %x",
+ cmd, cmd->status);
+
+ if ((cmd->cdb[0] == RESERVE) || (cmd->cdb[0] == RESERVE_10)) {
+ if (!test_bit(SCST_TGT_DEV_RESERVED,
+ &cmd->tgt_dev->tgt_dev_flags)) {
+ struct scst_tgt_dev *tgt_dev_tmp;
+ struct scst_device *dev = cmd->dev;
+
+ TRACE(TRACE_SCSI, "RESERVE failed lun=%lld, "
+ "status=%x",
+ (long long unsigned int)cmd->lun,
+ cmd->status);
+ PRINT_BUFF_FLAG(TRACE_SCSI, "Sense", cmd->sense,
+ cmd->sense_valid_len);
+
+ /* Clearing the reservation */
+ spin_lock_bh(&dev->dev_lock);
+ list_for_each_entry(tgt_dev_tmp,
+ &dev->dev_tgt_dev_list,
+ dev_tgt_dev_list_entry) {
+ clear_bit(SCST_TGT_DEV_RESERVED,
+ &tgt_dev_tmp->tgt_dev_flags);
+ }
+ dev->dev_reserved = 0;
+ spin_unlock_bh(&dev->dev_lock);
+ }
+ }
+
+ /* Check for MODE PARAMETERS CHANGED UA */
+ if ((cmd->dev->scsi_dev != NULL) &&
+ (cmd->status == SAM_STAT_CHECK_CONDITION) &&
+ scst_is_ua_sense(cmd->sense, cmd->sense_valid_len) &&
+ scst_analyze_sense(cmd->sense, cmd->sense_valid_len,
+ SCST_SENSE_ASCx_VALID,
+ 0, 0x2a, 0x01)) {
+ TRACE(TRACE_SCSI, "MODE PARAMETERS CHANGED UA (lun "
+ "%lld)", (long long unsigned int)cmd->lun);
+ cmd->state = SCST_CMD_STATE_MODE_SELECT_CHECKS;
+ goto out;
+ }
+ }
+
+ cmd->state = SCST_CMD_STATE_DEV_DONE;
+
+out:
+ return res;
+}
+
+static int scst_mode_select_checks(struct scst_cmd *cmd)
+{
+ int res = SCST_CMD_STATE_RES_CONT_SAME;
+ int atomic = scst_cmd_atomic(cmd);
+
+ if (likely(scsi_status_is_good(cmd->status))) {
+ if (unlikely((cmd->cdb[0] == MODE_SELECT) ||
+ (cmd->cdb[0] == MODE_SELECT_10) ||
+ (cmd->cdb[0] == LOG_SELECT))) {
+ struct scst_device *dev = cmd->dev;
+ int sl;
+ uint8_t sense_buffer[SCST_STANDARD_SENSE_LEN];
+
+ if (atomic && (dev->scsi_dev != NULL)) {
+ TRACE_DBG("%s", "MODE/LOG SELECT: thread "
+ "context required");
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ goto out;
+ }
+
+ TRACE(TRACE_SCSI, "MODE/LOG SELECT succeeded, "
+ "setting the SELECT UA (lun=%lld)",
+ (long long unsigned int)cmd->lun);
+
+ spin_lock_bh(&dev->dev_lock);
+ if (cmd->cdb[0] == LOG_SELECT) {
+ sl = scst_set_sense(sense_buffer,
+ sizeof(sense_buffer),
+ dev->d_sense,
+ UNIT_ATTENTION, 0x2a, 0x02);
+ } else {
+ sl = scst_set_sense(sense_buffer,
+ sizeof(sense_buffer),
+ dev->d_sense,
+ UNIT_ATTENTION, 0x2a, 0x01);
+ }
+ scst_dev_check_set_local_UA(dev, cmd, sense_buffer, sl);
+ spin_unlock_bh(&dev->dev_lock);
+
+ if (dev->scsi_dev != NULL)
+ scst_obtain_device_parameters(dev);
+ }
+ } else if ((cmd->status == SAM_STAT_CHECK_CONDITION) &&
+ scst_is_ua_sense(cmd->sense, cmd->sense_valid_len) &&
+ /* mode parameters changed */
+ (scst_analyze_sense(cmd->sense, cmd->sense_valid_len,
+ SCST_SENSE_ASCx_VALID,
+ 0, 0x2a, 0x01) ||
+ scst_analyze_sense(cmd->sense, cmd->sense_valid_len,
+ SCST_SENSE_ASC_VALID,
+ 0, 0x29, 0) /* reset */ ||
+ scst_analyze_sense(cmd->sense, cmd->sense_valid_len,
+ SCST_SENSE_ASC_VALID,
+ 0, 0x28, 0) /* medium changed */ ||
+ /* cleared by another ini (just in case) */
+ scst_analyze_sense(cmd->sense, cmd->sense_valid_len,
+ SCST_SENSE_ASC_VALID,
+ 0, 0x2F, 0))) {
+ if (atomic) {
+ TRACE_DBG("Possible parameters changed UA %x: "
+ "thread context required", cmd->sense[12]);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ goto out;
+ }
+
+ TRACE(TRACE_SCSI, "Possible parameters changed UA %x "
+ "(LUN %lld): getting new parameters", cmd->sense[12],
+ (long long unsigned int)cmd->lun);
+
+ scst_obtain_device_parameters(cmd->dev);
+ } else
+ BUG();
+
+ cmd->state = SCST_CMD_STATE_DEV_DONE;
+
+out:
+ return res;
+}
+
+static void scst_inc_check_expected_sn(struct scst_cmd *cmd)
+{
+ if (likely(cmd->sn_set))
+ scst_inc_expected_sn(cmd->tgt_dev, cmd->sn_slot);
+
+ scst_make_deferred_commands_active(cmd->tgt_dev);
+}
+
+static int scst_dev_done(struct scst_cmd *cmd)
+{
+ int res = SCST_CMD_STATE_RES_CONT_SAME;
+ int state;
+ struct scst_device *dev = cmd->dev;
+
+ state = SCST_CMD_STATE_PRE_XMIT_RESP;
+
+ if (likely(!scst_is_cmd_fully_local(cmd)) &&
+ likely(dev->handler->dev_done != NULL)) {
+ int rc;
+
+ if (unlikely(!dev->handler->dev_done_atomic &&
+ scst_cmd_atomic(cmd))) {
+ /*
+ * It shouldn't be because of the SCST_TGT_DEV_AFTER_*
+ * optimization.
+ */
+ TRACE_DBG("Dev handler %s dev_done() needs thread "
+ "context, rescheduling", dev->handler->name);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ goto out;
+ }
+
+ TRACE_DBG("Calling dev handler %s dev_done(%p)",
+ dev->handler->name, cmd);
+ scst_set_cur_start(cmd);
+ rc = dev->handler->dev_done(cmd);
+ scst_set_dev_done_time(cmd);
+ TRACE_DBG("Dev handler %s dev_done() returned %d",
+ dev->handler->name, rc);
+ if (rc != SCST_CMD_STATE_DEFAULT)
+ state = rc;
+ }
+
+ switch (state) {
+#ifdef CONFIG_SCST_EXTRACHECKS
+ case SCST_CMD_STATE_PRE_XMIT_RESP:
+ case SCST_CMD_STATE_DEV_PARSE:
+ case SCST_CMD_STATE_PRE_PARSE:
+ case SCST_CMD_STATE_PREPARE_SPACE:
+ case SCST_CMD_STATE_RDY_TO_XFER:
+ case SCST_CMD_STATE_TGT_PRE_EXEC:
+ case SCST_CMD_STATE_SEND_FOR_EXEC:
+ case SCST_CMD_STATE_LOCAL_EXEC:
+ case SCST_CMD_STATE_REAL_EXEC:
+ case SCST_CMD_STATE_PRE_DEV_DONE:
+ case SCST_CMD_STATE_MODE_SELECT_CHECKS:
+ case SCST_CMD_STATE_DEV_DONE:
+ case SCST_CMD_STATE_XMIT_RESP:
+ case SCST_CMD_STATE_FINISHED:
+ case SCST_CMD_STATE_FINISHED_INTERNAL:
+#else
+ default:
+#endif
+ cmd->state = state;
+ break;
+ case SCST_CMD_STATE_NEED_THREAD_CTX:
+ TRACE_DBG("Dev handler %s dev_done() requested "
+ "thread context, rescheduling",
+ dev->handler->name);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ break;
+#ifdef CONFIG_SCST_EXTRACHECKS
+ default:
+ if (state >= 0) {
+ PRINT_ERROR("Dev handler %s dev_done() returned "
+ "invalid cmd state %d",
+ dev->handler->name, state);
+ } else {
+ PRINT_ERROR("Dev handler %s dev_done() returned "
+ "error %d", dev->handler->name,
+ state);
+ }
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_hardw_error));
+ scst_set_cmd_abnormal_done_state(cmd);
+ break;
+#endif
+ }
+
+ if (cmd->needs_unblocking)
+ scst_unblock_dev_cmd(cmd);
+
+ if (likely(cmd->dec_on_dev_needed))
+ scst_dec_on_dev_cmd(cmd);
+
+ if (cmd->inc_expected_sn_on_done && cmd->sent_for_exec)
+ scst_inc_check_expected_sn(cmd);
+
+ if (unlikely(cmd->internal))
+ cmd->state = SCST_CMD_STATE_FINISHED_INTERNAL;
+
+out:
+ return res;
+}
+
+static int scst_pre_xmit_response(struct scst_cmd *cmd)
+{
+ int res;
+
+ EXTRACHECKS_BUG_ON(cmd->internal);
+
+#ifdef CONFIG_SCST_DEBUG_TM
+ if (cmd->tm_dbg_delayed &&
+ !test_bit(SCST_CMD_ABORTED, &cmd->cmd_flags)) {
+ if (scst_cmd_atomic(cmd)) {
+ TRACE_MGMT_DBG("%s",
+ "DEBUG_TM delayed cmd needs a thread");
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ return res;
+ }
+ TRACE_MGMT_DBG("Delaying cmd %p (tag %llu) for 1 second",
+ cmd, cmd->tag);
+ schedule_timeout_uninterruptible(HZ);
+ }
+#endif
+
+ if (likely(cmd->tgt_dev != NULL)) {
+ /*
+ * Those counters protect from not getting too long processing
+ * latency, so we should decrement them after cmd completed.
+ */
+ atomic_dec(&cmd->tgt_dev->tgt_dev_cmd_count);
+#ifdef CONFIG_SCST_PER_DEVICE_CMD_COUNT_LIMIT
+ atomic_dec(&cmd->dev->dev_cmd_count);
+#endif
+#ifdef CONFIG_SCST_ORDERED_READS
+ /* If expected values not set, expected direction is UNKNOWN */
+ if (cmd->expected_data_direction & SCST_DATA_WRITE)
+ atomic_dec(&cmd->dev->write_cmd_count);
+#endif
+ if (unlikely(cmd->queue_type == SCST_CMD_QUEUE_HEAD_OF_QUEUE))
+ scst_on_hq_cmd_response(cmd);
+
+ if (unlikely(!cmd->sent_for_exec)) {
+ TRACE_SN("cmd %p was not sent to mid-lev"
+ " (sn %d, set %d)",
+ cmd, cmd->sn, cmd->sn_set);
+ scst_unblock_deferred(cmd->tgt_dev, cmd);
+ cmd->sent_for_exec = 1;
+ }
+ }
+
+ cmd->done = 1;
+ smp_mb(); /* to sync with scst_abort_cmd() */
+
+ if (unlikely(test_bit(SCST_CMD_ABORTED, &cmd->cmd_flags)))
+ scst_xmit_process_aborted_cmd(cmd);
+ else if (unlikely(cmd->status == SAM_STAT_CHECK_CONDITION))
+ scst_store_sense(cmd);
+
+ if (unlikely(test_bit(SCST_CMD_NO_RESP, &cmd->cmd_flags))) {
+ TRACE_MGMT_DBG("Flag NO_RESP set for cmd %p (tag %llu),"
+ " skipping",
+ cmd, (long long unsigned int)cmd->tag);
+ cmd->state = SCST_CMD_STATE_FINISHED;
+ res = SCST_CMD_STATE_RES_CONT_SAME;
+ goto out;
+ }
+
+ cmd->state = SCST_CMD_STATE_XMIT_RESP;
+ res = SCST_CMD_STATE_RES_CONT_SAME;
+
+out:
+ return res;
+}
+
+static int scst_xmit_response(struct scst_cmd *cmd)
+{
+ struct scst_tgt_template *tgtt = cmd->tgtt;
+ int res, rc;
+
+ EXTRACHECKS_BUG_ON(cmd->internal);
+
+ if (unlikely(!tgtt->xmit_response_atomic &&
+ scst_cmd_atomic(cmd))) {
+ /*
+ * It shouldn't be because of the SCST_TGT_DEV_AFTER_*
+ * optimization.
+ */
+ TRACE_DBG("Target driver %s xmit_response() needs thread "
+ "context, rescheduling", tgtt->name);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ goto out;
+ }
+
+ while (1) {
+ int finished_cmds = atomic_read(&cmd->tgt->finished_cmds);
+
+ res = SCST_CMD_STATE_RES_CONT_NEXT;
+ cmd->state = SCST_CMD_STATE_XMIT_WAIT;
+
+ TRACE_DBG("Calling xmit_response(%p)", cmd);
+
+#if defined(CONFIG_SCST_DEBUG) || defined(CONFIG_SCST_TRACING)
+ if (trace_flag & TRACE_SND_BOT) {
+ int i;
+ struct scatterlist *sg;
+ if (cmd->tgt_sg != NULL)
+ sg = cmd->tgt_sg;
+ else
+ sg = cmd->sg;
+ if (sg != NULL) {
+ TRACE(TRACE_SND_BOT, "Xmitting data for cmd %p "
+ "(sg_cnt %d, sg %p, sg[0].page %p)",
+ cmd, cmd->tgt_sg_cnt, sg,
+ (void *)sg_page(&sg[0]));
+ for (i = 0; i < cmd->tgt_sg_cnt; ++i) {
+ PRINT_BUFF_FLAG(TRACE_SND_BOT,
+ "Xmitting sg", sg_virt(&sg[i]),
+ sg[i].length);
+ }
+ }
+ }
+#endif
+
+ if (tgtt->on_hw_pending_cmd_timeout != NULL) {
+ struct scst_session *sess = cmd->sess;
+ cmd->hw_pending_start = jiffies;
+ cmd->cmd_hw_pending = 1;
+ if (!test_bit(SCST_SESS_HW_PENDING_WORK_SCHEDULED, &sess->sess_aflags)) {
+ TRACE_DBG("Sched HW pending work for sess %p "
+ "(max time %d)", sess,
+ tgtt->max_hw_pending_time);
+ set_bit(SCST_SESS_HW_PENDING_WORK_SCHEDULED,
+ &sess->sess_aflags);
+ schedule_delayed_work(&sess->hw_pending_work,
+ tgtt->max_hw_pending_time * HZ);
+ }
+ }
+
+ scst_set_cur_start(cmd);
+
+#ifdef CONFIG_SCST_DEBUG_RETRY
+ if (((scst_random() % 100) == 77))
+ rc = SCST_TGT_RES_QUEUE_FULL;
+ else
+#endif
+ rc = tgtt->xmit_response(cmd);
+ TRACE_DBG("xmit_response() returned %d", rc);
+
+ if (likely(rc == SCST_TGT_RES_SUCCESS))
+ goto out;
+
+ scst_set_xmit_time(cmd);
+
+ cmd->cmd_hw_pending = 0;
+
+ /* Restore the previous state */
+ cmd->state = SCST_CMD_STATE_XMIT_RESP;
+
+ switch (rc) {
+ case SCST_TGT_RES_QUEUE_FULL:
+ if (scst_queue_retry_cmd(cmd, finished_cmds) == 0)
+ break;
+ else
+ continue;
+
+ case SCST_TGT_RES_NEED_THREAD_CTX:
+ TRACE_DBG("Target driver %s xmit_response() "
+ "requested thread context, rescheduling",
+ tgtt->name);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ break;
+
+ default:
+ goto out_error;
+ }
+ break;
+ }
+
+out:
+ /* Caution: cmd can be already dead here */
+ return res;
+
+out_error:
+ if (rc == SCST_TGT_RES_FATAL_ERROR) {
+ PRINT_ERROR("Target driver %s xmit_response() returned "
+ "fatal error", tgtt->name);
+ } else {
+ PRINT_ERROR("Target driver %s xmit_response() returned "
+ "invalid value %d", tgtt->name, rc);
+ }
+ scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+ cmd->state = SCST_CMD_STATE_FINISHED;
+ res = SCST_CMD_STATE_RES_CONT_SAME;
+ goto out;
+}
+
+/**
+ * scst_tgt_cmd_done() - the command's processing done
+ * @cmd: SCST command
+ * @pref_context: preferred command execution context
+ *
+ * Description:
+ * Notifies SCST that the driver sent the response and the command
+ * can be freed now. Don't forget to set the delivery status, if it
+ * isn't success, using scst_set_delivery_status() before calling
+ * this function. The third argument sets preferred command execition
+ * context (see SCST_CONTEXT_* constants for details)
+ */
+void scst_tgt_cmd_done(struct scst_cmd *cmd,
+ enum scst_exec_context pref_context)
+{
+
+ BUG_ON(cmd->state != SCST_CMD_STATE_XMIT_WAIT);
+
+ scst_set_xmit_time(cmd);
+
+ cmd->cmd_hw_pending = 0;
+
+ cmd->state = SCST_CMD_STATE_FINISHED;
+ scst_process_redirect_cmd(cmd, pref_context, 1);
+ return;
+}
+EXPORT_SYMBOL(scst_tgt_cmd_done);
+
+static int scst_finish_cmd(struct scst_cmd *cmd)
+{
+ int res;
+ struct scst_session *sess = cmd->sess;
+
+ scst_update_lat_stats(cmd);
+
+ if (unlikely(cmd->delivery_status != SCST_CMD_DELIVERY_SUCCESS)) {
+ if ((cmd->tgt_dev != NULL) &&
+ scst_is_ua_sense(cmd->sense, cmd->sense_valid_len)) {
+ /* This UA delivery failed, so we need to requeue it */
+ if (scst_cmd_atomic(cmd) &&
+ scst_is_ua_global(cmd->sense, cmd->sense_valid_len)) {
+ TRACE_MGMT_DBG("Requeuing of global UA for "
+ "failed cmd %p needs a thread", cmd);
+ res = SCST_CMD_STATE_RES_NEED_THREAD;
+ goto out;
+ }
+ scst_requeue_ua(cmd);
+ }
+ }
+
+ atomic_dec(&sess->sess_cmd_count);
+
+ spin_lock_irq(&sess->sess_list_lock);
+ list_del(&cmd->sess_cmd_list_entry);
+ spin_unlock_irq(&sess->sess_list_lock);
+
+ cmd->finished = 1;
+ smp_mb(); /* to sync with scst_abort_cmd() */
+
+ if (unlikely(test_bit(SCST_CMD_ABORTED, &cmd->cmd_flags))) {
+ TRACE_MGMT_DBG("Aborted cmd %p finished (cmd_ref %d, "
+ "scst_cmd_count %d)", cmd, atomic_read(&cmd->cmd_ref),
+ atomic_read(&scst_cmd_count));
+
+ scst_finish_cmd_mgmt(cmd);
+ }
+
+ __scst_cmd_put(cmd);
+
+ res = SCST_CMD_STATE_RES_CONT_NEXT;
+
+out:
+ return res;
+}
+
+/*
+ * No locks, but it must be externally serialized (see comment for
+ * scst_cmd_init_done() in scst.h)
+ */
+static void scst_cmd_set_sn(struct scst_cmd *cmd)
+{
+ struct scst_tgt_dev *tgt_dev = cmd->tgt_dev;
+ unsigned long flags;
+
+ if (scst_is_implicit_hq(cmd)) {
+ TRACE_SN("Implicit HQ cmd %p", cmd);
+ cmd->queue_type = SCST_CMD_QUEUE_HEAD_OF_QUEUE;
+ }
+
+ EXTRACHECKS_BUG_ON(cmd->sn_set || cmd->hq_cmd_inced);
+
+ /* Optimized for lockless fast path */
+
+ scst_check_debug_sn(cmd);
+
+#ifdef CONFIG_SCST_STRICT_SERIALIZING
+ cmd->queue_type = SCST_CMD_QUEUE_ORDERED;
+#endif
+
+ if (cmd->dev->queue_alg == SCST_CONTR_MODE_QUEUE_ALG_RESTRICTED_REORDER) {
+ /*
+ * Not the best way, but good enough until there is a
+ * possibility to specify queue type during pass-through
+ * commands submission.
+ */
+ cmd->queue_type = SCST_CMD_QUEUE_ORDERED;
+ }
+
+ switch (cmd->queue_type) {
+ case SCST_CMD_QUEUE_SIMPLE:
+ case SCST_CMD_QUEUE_UNTAGGED:
+#ifdef CONFIG_SCST_ORDERED_READS
+ if (scst_cmd_is_expected_set(cmd)) {
+ if ((cmd->expected_data_direction == SCST_DATA_READ) &&
+ (atomic_read(&cmd->dev->write_cmd_count) == 0))
+ goto ordered;
+ } else
+ goto ordered;
+#endif
+ if (likely(tgt_dev->num_free_sn_slots >= 0)) {
+ /*
+ * atomic_inc_return() implies memory barrier to sync
+ * with scst_inc_expected_sn()
+ */
+ if (atomic_inc_return(tgt_dev->cur_sn_slot) == 1) {
+ tgt_dev->curr_sn++;
+ TRACE_SN("Incremented curr_sn %d",
+ tgt_dev->curr_sn);
+ }
+ cmd->sn_slot = tgt_dev->cur_sn_slot;
+ cmd->sn = tgt_dev->curr_sn;
+
+ tgt_dev->prev_cmd_ordered = 0;
+ } else {
+ TRACE(TRACE_MINOR, "***WARNING*** Not enough SN slots "
+ "%zd", ARRAY_SIZE(tgt_dev->sn_slots));
+ goto ordered;
+ }
+ break;
+
+ case SCST_CMD_QUEUE_ORDERED:
+ TRACE_SN("ORDERED cmd %p (op %x)", cmd, cmd->cdb[0]);
+ordered:
+ if (!tgt_dev->prev_cmd_ordered) {
+ spin_lock_irqsave(&tgt_dev->sn_lock, flags);
+ if (tgt_dev->num_free_sn_slots >= 0) {
+ tgt_dev->num_free_sn_slots--;
+ if (tgt_dev->num_free_sn_slots >= 0) {
+ int i = 0;
+ /* Commands can finish in any order, so
+ * we don't know which slot is empty.
+ */
+ while (1) {
+ tgt_dev->cur_sn_slot++;
+ if (tgt_dev->cur_sn_slot ==
+ tgt_dev->sn_slots + ARRAY_SIZE(tgt_dev->sn_slots))
+ tgt_dev->cur_sn_slot = tgt_dev->sn_slots;
+
+ if (atomic_read(tgt_dev->cur_sn_slot) == 0)
+ break;
+
+ i++;
+ BUG_ON(i == ARRAY_SIZE(tgt_dev->sn_slots));
+ }
+ TRACE_SN("New cur SN slot %zd",
+ tgt_dev->cur_sn_slot -
+ tgt_dev->sn_slots);
+ }
+ }
+ spin_unlock_irqrestore(&tgt_dev->sn_lock, flags);
+ }
+ tgt_dev->prev_cmd_ordered = 1;
+ tgt_dev->curr_sn++;
+ cmd->sn = tgt_dev->curr_sn;
+ break;
+
+ case SCST_CMD_QUEUE_HEAD_OF_QUEUE:
+ TRACE_SN("HQ cmd %p (op %x)", cmd, cmd->cdb[0]);
+ spin_lock_irqsave(&tgt_dev->sn_lock, flags);
+ tgt_dev->hq_cmd_count++;
+ spin_unlock_irqrestore(&tgt_dev->sn_lock, flags);
+ cmd->hq_cmd_inced = 1;
+ goto out;
+
+ default:
+ BUG();
+ }
+
+ TRACE_SN("cmd(%p)->sn: %d (tgt_dev %p, *cur_sn_slot %d, "
+ "num_free_sn_slots %d, prev_cmd_ordered %ld, "
+ "cur_sn_slot %zd)", cmd, cmd->sn, tgt_dev,
+ atomic_read(tgt_dev->cur_sn_slot),
+ tgt_dev->num_free_sn_slots, tgt_dev->prev_cmd_ordered,
+ tgt_dev->cur_sn_slot-tgt_dev->sn_slots);
+
+ cmd->sn_set = 1;
+
+out:
+ return;
+}
+
+/*
+ * Returns 0 on success, > 0 when we need to wait for unblock,
+ * < 0 if there is no device (lun) or device type handler.
+ *
+ * No locks, but might be on IRQ, protection is done by the
+ * suspended activity.
+ */
+static int scst_translate_lun(struct scst_cmd *cmd)
+{
+ struct scst_tgt_dev *tgt_dev = NULL;
+ int res;
+
+ /* See comment about smp_mb() in scst_suspend_activity() */
+ __scst_get(1);
+
+ if (likely(!test_bit(SCST_FLAG_SUSPENDED, &scst_flags))) {
+ struct list_head *sess_tgt_dev_list_head =
+ &cmd->sess->sess_tgt_dev_list_hash[HASH_VAL(cmd->lun)];
+ TRACE_DBG("Finding tgt_dev for cmd %p (lun %lld)", cmd,
+ (long long unsigned int)cmd->lun);
+ res = -1;
+ list_for_each_entry(tgt_dev, sess_tgt_dev_list_head,
+ sess_tgt_dev_list_entry) {
+ if (tgt_dev->lun == cmd->lun) {
+ TRACE_DBG("tgt_dev %p found", tgt_dev);
+
+ if (unlikely(tgt_dev->dev->handler ==
+ &scst_null_devtype)) {
+ PRINT_INFO("Dev handler for device "
+ "%lld is NULL, the device will not "
+ "be visible remotely",
+ (long long unsigned int)cmd->lun);
+ break;
+ }
+
+ cmd->cmd_threads = tgt_dev->active_cmd_threads;
+ cmd->tgt_dev = tgt_dev;
+ cmd->dev = tgt_dev->dev;
+
+ res = 0;
+ break;
+ }
+ }
+ if (res != 0) {
+ TRACE(TRACE_MINOR,
+ "tgt_dev for LUN %lld not found, command to "
+ "unexisting LU?",
+ (long long unsigned int)cmd->lun);
+ __scst_put();
+ }
+ } else {
+ TRACE_MGMT_DBG("%s", "FLAG SUSPENDED set, skipping");
+ __scst_put();
+ res = 1;
+ }
+ return res;
+}
+
+/*
+ * No locks, but might be on IRQ.
+ *
+ * Returns 0 on success, > 0 when we need to wait for unblock,
+ * < 0 if there is no device (lun) or device type handler.
+ */
+static int __scst_init_cmd(struct scst_cmd *cmd)
+{
+ int res = 0;
+
+ res = scst_translate_lun(cmd);
+ if (likely(res == 0)) {
+ int cnt;
+ bool failure = false;
+
+ cmd->state = SCST_CMD_STATE_PRE_PARSE;
+
+ cnt = atomic_inc_return(&cmd->tgt_dev->tgt_dev_cmd_count);
+ if (unlikely(cnt > SCST_MAX_TGT_DEV_COMMANDS)) {
+ TRACE(TRACE_FLOW_CONTROL,
+ "Too many pending commands (%d) in "
+ "session, returning BUSY to initiator \"%s\"",
+ cnt, (cmd->sess->initiator_name[0] == '\0') ?
+ "Anonymous" : cmd->sess->initiator_name);
+ failure = true;
+ }
+
+#ifdef CONFIG_SCST_PER_DEVICE_CMD_COUNT_LIMIT
+ cnt = atomic_inc_return(&cmd->dev->dev_cmd_count);
+ if (unlikely(cnt > SCST_MAX_DEV_COMMANDS)) {
+ if (!failure) {
+ TRACE(TRACE_FLOW_CONTROL,
+ "Too many pending device "
+ "commands (%d), returning BUSY to "
+ "initiator \"%s\"", cnt,
+ (cmd->sess->initiator_name[0] == '\0') ?
+ "Anonymous" :
+ cmd->sess->initiator_name);
+ failure = true;
+ }
+ }
+#endif
+
+#ifdef CONFIG_SCST_ORDERED_READS
+ /* If expected values not set, expected direction is UNKNOWN */
+ if (cmd->expected_data_direction & SCST_DATA_WRITE)
+ atomic_inc(&cmd->dev->write_cmd_count);
+#endif
+
+ if (unlikely(failure))
+ goto out_busy;
+
+ if (!cmd->set_sn_on_restart_cmd)
+ scst_cmd_set_sn(cmd);
+ } else if (res < 0) {
+ TRACE_DBG("Finishing cmd %p", cmd);
+ scst_set_cmd_error(cmd,
+ SCST_LOAD_SENSE(scst_sense_lun_not_supported));
+ scst_set_cmd_abnormal_done_state(cmd);
+ } else
+ goto out;
+
+out:
+ return res;
+
+out_busy:
+ scst_set_busy(cmd);
+ scst_set_cmd_abnormal_done_state(cmd);
+ goto out;
+}
+
+/* Called under scst_init_lock and IRQs disabled */
+static void scst_do_job_init(void)
+ __releases(&scst_init_lock)
+ __acquires(&scst_init_lock)
+{
+ struct scst_cmd *cmd;
+ int susp;
+
+restart:
+ /*
+ * There is no need for read barrier here, because we don't care where
+ * this check will be done.
+ */
+ susp = test_bit(SCST_FLAG_SUSPENDED, &scst_flags);
+ if (scst_init_poll_cnt > 0)
+ scst_init_poll_cnt--;
+
+ list_for_each_entry(cmd, &scst_init_cmd_list, cmd_list_entry) {
+ int rc;
+ if (susp && !test_bit(SCST_CMD_ABORTED, &cmd->cmd_flags))
+ continue;
+ if (!test_bit(SCST_CMD_ABORTED, &cmd->cmd_flags)) {
+ spin_unlock_irq(&scst_init_lock);
+ rc = __scst_init_cmd(cmd);
+ spin_lock_irq(&scst_init_lock);
+ if (rc > 0) {
+ TRACE_MGMT_DBG("%s",
+ "FLAG SUSPENDED set, restarting");
+ goto restart;
+ }
+ } else {
+ TRACE_MGMT_DBG("Aborting not inited cmd %p (tag %llu)",
+ cmd, (long long unsigned int)cmd->tag);
+ scst_set_cmd_abnormal_done_state(cmd);
+ }
+
+ /*
+ * Deleting cmd from init cmd list after __scst_init_cmd()
+ * is necessary to keep the check in scst_init_cmd() correct
+ * to preserve the commands order.
+ *
+ * We don't care about the race, when init cmd list is empty
+ * and one command detected that it just was not empty, so
+ * it's inserting to it, but another command at the same time
+ * seeing init cmd list empty and goes directly, because it
+ * could affect only commands from the same initiator to the
+ * same tgt_dev, but scst_cmd_init_done*() doesn't guarantee
+ * the order in case of simultaneous such calls anyway.
+ */
+ TRACE_MGMT_DBG("Deleting cmd %p from init cmd list", cmd);
+ smp_wmb(); /* enforce the required order */
+ list_del(&cmd->cmd_list_entry);
+ spin_unlock(&scst_init_lock);
+
+ spin_lock(&cmd->cmd_threads->cmd_list_lock);
+ TRACE_MGMT_DBG("Adding cmd %p to active cmd list", cmd);
+ if (unlikely(cmd->queue_type == SCST_CMD_QUEUE_HEAD_OF_QUEUE))
+ list_add(&cmd->cmd_list_entry,
+ &cmd->cmd_threads->active_cmd_list);
+ else
+ list_add_tail(&cmd->cmd_list_entry,
+ &cmd->cmd_threads->active_cmd_list);
+ wake_up(&cmd->cmd_threads->cmd_list_waitQ);
+ spin_unlock(&cmd->cmd_threads->cmd_list_lock);
+
+ spin_lock(&scst_init_lock);
+ goto restart;
+ }
+
+ /* It isn't really needed, but let's keep it */
+ if (susp != test_bit(SCST_FLAG_SUSPENDED, &scst_flags))
+ goto restart;
+ return;
+}
+
+static inline int test_init_cmd_list(void)
+{
+ int res = (!list_empty(&scst_init_cmd_list) &&
+ !test_bit(SCST_FLAG_SUSPENDED, &scst_flags)) ||
+ unlikely(kthread_should_stop()) ||
+ (scst_init_poll_cnt > 0);
+ return res;
+}
+
+int scst_init_thread(void *arg)
+{
+
+ PRINT_INFO("Init thread started, PID %d", current->pid);
+
+ current->flags |= PF_NOFREEZE;
+
+ set_user_nice(current, -10);
+
+ spin_lock_irq(&scst_init_lock);
+ while (!kthread_should_stop()) {
+ wait_queue_t wait;
+ init_waitqueue_entry(&wait, current);
+
+ if (!test_init_cmd_list()) {
+ add_wait_queue_exclusive(&scst_init_cmd_list_waitQ,
+ &wait);
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (test_init_cmd_list())
+ break;
+ spin_unlock_irq(&scst_init_lock);
+ schedule();
+ spin_lock_irq(&scst_init_lock);
+ }
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&scst_init_cmd_list_waitQ, &wait);
+ }
+ scst_do_job_init();
+ }
+ spin_unlock_irq(&scst_init_lock);
+
+ /*
+ * If kthread_should_stop() is true, we are guaranteed to be
+ * on the module unload, so scst_init_cmd_list must be empty.
+ */
+ BUG_ON(!list_empty(&scst_init_cmd_list));
+
+ PRINT_INFO("Init thread PID %d finished", current->pid);
+ return 0;
+}
+
+/**
+ * scst_process_active_cmd() - process active command
+ *
+ * Description:
+ * Main SCST commands processing routing. Must be used only by dev handlers.
+ *
+ * Argument atomic is true, if function called in atomic context.
+ *
+ * Must be called with no locks held.
+ */
+void scst_process_active_cmd(struct scst_cmd *cmd, bool atomic)
+{
+ int res;
+
+ /*
+ * Checkpatch will complain on the use of in_atomic() below. You
+ * can safely ignore this warning since in_atomic() is used here only
+ * for debugging purposes.
+ */
+ EXTRACHECKS_BUG_ON(in_irq() || irqs_disabled());
+ EXTRACHECKS_WARN_ON((in_atomic() || in_interrupt() || irqs_disabled()) &&
+ !atomic);
+
+ cmd->atomic = atomic;
+
+ TRACE_DBG("cmd %p, atomic %d", cmd, atomic);
+
+ do {
+ switch (cmd->state) {
+ case SCST_CMD_STATE_PRE_PARSE:
+ res = scst_pre_parse(cmd);
+ EXTRACHECKS_BUG_ON(res ==
+ SCST_CMD_STATE_RES_NEED_THREAD);
+ break;
+
+ case SCST_CMD_STATE_DEV_PARSE:
+ res = scst_parse_cmd(cmd);
+ break;
+
+ case SCST_CMD_STATE_PREPARE_SPACE:
+ res = scst_prepare_space(cmd);
+ break;
+
+ case SCST_CMD_STATE_PREPROCESSING_DONE:
+ res = scst_preprocessing_done(cmd);
+ break;
+
+ case SCST_CMD_STATE_RDY_TO_XFER:
+ res = scst_rdy_to_xfer(cmd);
+ break;
+
+ case SCST_CMD_STATE_TGT_PRE_EXEC:
+ res = scst_tgt_pre_exec(cmd);
+ break;
+
+ case SCST_CMD_STATE_SEND_FOR_EXEC:
+ if (tm_dbg_check_cmd(cmd) != 0) {
+ res = SCST_CMD_STATE_RES_CONT_NEXT;
+ TRACE_MGMT_DBG("Skipping cmd %p (tag %llu), "
+ "because of TM DBG delay", cmd,
+ (long long unsigned int)cmd->tag);
+ break;
+ }
+ res = scst_send_for_exec(&cmd);
+ /*
+ * !! At this point cmd, sess & tgt_dev can already be
+ * freed !!
+ */
+ break;
+
+ case SCST_CMD_STATE_LOCAL_EXEC:
+ res = scst_local_exec(cmd);
+ /*
+ * !! At this point cmd, sess & tgt_dev can already be
+ * freed !!
+ */
+ break;
+
+ case SCST_CMD_STATE_REAL_EXEC:
+ res = scst_real_exec(cmd);
+ /*
+ * !! At this point cmd, sess & tgt_dev can already be
+ * freed !!
+ */
+ break;
+
+ case SCST_CMD_STATE_PRE_DEV_DONE:
+ res = scst_pre_dev_done(cmd);
+ EXTRACHECKS_BUG_ON(res ==
+ SCST_CMD_STATE_RES_NEED_THREAD);
+ break;
+
+ case SCST_CMD_STATE_MODE_SELECT_CHECKS:
+ res = scst_mode_select_checks(cmd);
+ break;
+
+ case SCST_CMD_STATE_DEV_DONE:
+ res = scst_dev_done(cmd);
+ break;
+
+ case SCST_CMD_STATE_PRE_XMIT_RESP:
+ res = scst_pre_xmit_response(cmd);
+ EXTRACHECKS_BUG_ON(res ==
+ SCST_CMD_STATE_RES_NEED_THREAD);
+ break;
+
+ case SCST_CMD_STATE_XMIT_RESP:
+ res = scst_xmit_response(cmd);
+ break;
+
+ case SCST_CMD_STATE_FINISHED:
+ res = scst_finish_cmd(cmd);
+ break;
+
+ case SCST_CMD_STATE_FINISHED_INTERNAL:
+ res = scst_finish_internal_cmd(cmd);
+ EXTRACHECKS_BUG_ON(res ==
+ SCST_CMD_STATE_RES_NEED_THREAD);
+ break;
+
+ default:
+ PRINT_CRIT_ERROR("cmd (%p) in state %d, but shouldn't "
+ "be", cmd, cmd->state);
+ BUG();
+ res = SCST_CMD_STATE_RES_CONT_NEXT;
+ break;
+ }
+ } while (res == SCST_CMD_STATE_RES_CONT_SAME);
+
+ if (res == SCST_CMD_STATE_RES_CONT_NEXT) {
+ /* None */
+ } else if (res == SCST_CMD_STATE_RES_NEED_THREAD) {
+ spin_lock_irq(&cmd->cmd_threads->cmd_list_lock);
+#ifdef CONFIG_SCST_EXTRACHECKS
+ switch (cmd->state) {
+ case SCST_CMD_STATE_DEV_PARSE:
+ case SCST_CMD_STATE_PREPARE_SPACE:
+ case SCST_CMD_STATE_RDY_TO_XFER:
+ case SCST_CMD_STATE_TGT_PRE_EXEC:
+ case SCST_CMD_STATE_SEND_FOR_EXEC:
+ case SCST_CMD_STATE_LOCAL_EXEC:
+ case SCST_CMD_STATE_REAL_EXEC:
+ case SCST_CMD_STATE_DEV_DONE:
+ case SCST_CMD_STATE_XMIT_RESP:
+#endif
+ TRACE_DBG("Adding cmd %p to head of active cmd list",
+ cmd);
+ list_add(&cmd->cmd_list_entry,
+ &cmd->cmd_threads->active_cmd_list);
+#ifdef CONFIG_SCST_EXTRACHECKS
+ break;
+ default:
+ PRINT_CRIT_ERROR("cmd %p is in invalid state %d)", cmd,
+ cmd->state);
+ spin_unlock_irq(&cmd->cmd_threads->cmd_list_lock);
+ BUG();
+ spin_lock_irq(&cmd->cmd_threads->cmd_list_lock);
+ break;
+ }
+#endif
+ wake_up(&cmd->cmd_threads->cmd_list_waitQ);
+ spin_unlock_irq(&cmd->cmd_threads->cmd_list_lock);
+ } else
+ BUG();
+ return;
+}
+EXPORT_SYMBOL_GPL(scst_process_active_cmd);
+
+/**
+ * scst_post_parse_process_active_cmd() - process command after parse
+ *
+ * SCST commands processing routine, which should be called by dev handler
+ * after its parse() callback returned SCST_CMD_STATE_STOP. Arguments are
+ * the same as for scst_process_active_cmd().
+ */
+void scst_post_parse_process_active_cmd(struct scst_cmd *cmd, bool atomic)
+{
+ scst_set_parse_time(cmd);
+ scst_process_active_cmd(cmd, atomic);
+}
+EXPORT_SYMBOL_GPL(scst_post_parse_process_active_cmd);
+
+/* Called under cmd_list_lock and IRQs disabled */
+static void scst_do_job_active(struct list_head *cmd_list,
+ spinlock_t *cmd_list_lock, bool atomic)
+ __releases(cmd_list_lock)
+ __acquires(cmd_list_lock)
+{
+
+ while (!list_empty(cmd_list)) {
+ struct scst_cmd *cmd = list_entry(cmd_list->next, typeof(*cmd),
+ cmd_list_entry);
+ TRACE_DBG("Deleting cmd %p from active cmd list", cmd);
+ list_del(&cmd->cmd_list_entry);
+ spin_unlock_irq(cmd_list_lock);
+ scst_process_active_cmd(cmd, atomic);
+ spin_lock_irq(cmd_list_lock);
+ }
+ return;
+}
+
+static inline int test_cmd_threads(struct scst_cmd_threads *p_cmd_threads)
+{
+ int res = !list_empty(&p_cmd_threads->active_cmd_list) ||
+ unlikely(kthread_should_stop()) ||
+ tm_dbg_is_release();
+ return res;
+}
+
+int scst_cmd_thread(void *arg)
+{
+ struct scst_cmd_threads *p_cmd_threads = (struct scst_cmd_threads *)arg;
+ static DEFINE_MUTEX(io_context_mutex);
+
+ PRINT_INFO("Processing thread %s (PID %d) started", current->comm,
+ current->pid);
+
+#if 0
+ set_user_nice(current, 10);
+#endif
+ current->flags |= PF_NOFREEZE;
+
+ mutex_lock(&io_context_mutex);
+
+ WARN_ON(current->io_context);
+
+ if (p_cmd_threads != &scst_main_cmd_threads) {
+ if (p_cmd_threads->io_context == NULL) {
+ p_cmd_threads->io_context = get_io_context(GFP_KERNEL, -1);
+ TRACE_MGMT_DBG("Alloced new IO context %p "
+ "(p_cmd_threads %p)",
+ p_cmd_threads->io_context,
+ p_cmd_threads);
+ /* It's ref counted via threads */
+ put_io_context(p_cmd_threads->io_context);
+ } else {
+ put_io_context(current->io_context);
+ current->io_context = ioc_task_link(p_cmd_threads->io_context);
+ TRACE_MGMT_DBG("Linked IO context %p "
+ "(p_cmd_threads %p)", p_cmd_threads->io_context,
+ p_cmd_threads);
+ }
+ }
+
+ mutex_unlock(&io_context_mutex);
+
+ spin_lock_irq(&p_cmd_threads->cmd_list_lock);
+ while (!kthread_should_stop()) {
+ wait_queue_t wait;
+ init_waitqueue_entry(&wait, current);
+
+ if (!test_cmd_threads(p_cmd_threads)) {
+ add_wait_queue_exclusive_head(
+ &p_cmd_threads->cmd_list_waitQ,
+ &wait);
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (test_cmd_threads(p_cmd_threads))
+ break;
+ spin_unlock_irq(&p_cmd_threads->cmd_list_lock);
+ schedule();
+ spin_lock_irq(&p_cmd_threads->cmd_list_lock);
+ }
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&p_cmd_threads->cmd_list_waitQ, &wait);
+ }
+
+ if (tm_dbg_is_release()) {
+ spin_unlock_irq(&p_cmd_threads->cmd_list_lock);
+ tm_dbg_check_released_cmds();
+ spin_lock_irq(&p_cmd_threads->cmd_list_lock);
+ }
+
+ scst_do_job_active(&p_cmd_threads->active_cmd_list,
+ &p_cmd_threads->cmd_list_lock, false);
+ }
+ spin_unlock_irq(&p_cmd_threads->cmd_list_lock);
+
+ EXTRACHECKS_BUG_ON((p_cmd_threads->nr_threads == 1) &&
+ !list_empty(&p_cmd_threads->active_cmd_list));
+
+ if ((p_cmd_threads->nr_threads == 1) &&
+ (p_cmd_threads != &scst_main_cmd_threads))
+ p_cmd_threads->io_context = NULL;
+
+ PRINT_INFO("Processing thread %s (PID %d) finished", current->comm,
+ current->pid);
+ return 0;
+}
+
+void scst_cmd_tasklet(long p)
+{
+ struct scst_tasklet *t = (struct scst_tasklet *)p;
+
+ spin_lock_irq(&t->tasklet_lock);
+ scst_do_job_active(&t->tasklet_cmd_list, &t->tasklet_lock, true);
+ spin_unlock_irq(&t->tasklet_lock);
+ return;
+}
+
+/*
+ * Returns 0 on success, < 0 if there is no device handler or
+ * > 0 if SCST_FLAG_SUSPENDED set and SCST_FLAG_SUSPENDING - not.
+ * No locks, protection is done by the suspended activity.
+ */
+static int scst_mgmt_translate_lun(struct scst_mgmt_cmd *mcmd)
+{
+ struct scst_tgt_dev *tgt_dev = NULL;
+ struct list_head *sess_tgt_dev_list_head;
+ int res = -1;
+
+ TRACE_DBG("Finding tgt_dev for mgmt cmd %p (lun %lld)", mcmd,
+ (long long unsigned int)mcmd->lun);
+
+ /* See comment about smp_mb() in scst_suspend_activity() */
+ __scst_get(1);
+
+ if (unlikely(test_bit(SCST_FLAG_SUSPENDED, &scst_flags) &&
+ !test_bit(SCST_FLAG_SUSPENDING, &scst_flags))) {
+ TRACE_MGMT_DBG("%s", "FLAG SUSPENDED set, skipping");
+ __scst_put();
+ res = 1;
+ goto out;
+ }
+
+ sess_tgt_dev_list_head =
+ &mcmd->sess->sess_tgt_dev_list_hash[HASH_VAL(mcmd->lun)];
+ list_for_each_entry(tgt_dev, sess_tgt_dev_list_head,
+ sess_tgt_dev_list_entry) {
+ if (tgt_dev->lun == mcmd->lun) {
+ TRACE_DBG("tgt_dev %p found", tgt_dev);
+ mcmd->mcmd_tgt_dev = tgt_dev;
+ res = 0;
+ break;
+ }
+ }
+ if (mcmd->mcmd_tgt_dev == NULL)
+ __scst_put();
+
+out:
+ return res;
+}
+
+/* No locks */
+void scst_done_cmd_mgmt(struct scst_cmd *cmd)
+{
+ struct scst_mgmt_cmd_stub *mstb;
+ bool wake = 0;
+ unsigned long flags;
+
+ TRACE_MGMT_DBG("cmd %p done (tag %llu)",
+ cmd, (long long unsigned int)cmd->tag);
+
+ spin_lock_irqsave(&scst_mcmd_lock, flags);
+
+ list_for_each_entry(mstb, &cmd->mgmt_cmd_list,
+ cmd_mgmt_cmd_list_entry) {
+ struct scst_mgmt_cmd *mcmd;
+
+ if (!mstb->done_counted)
+ continue;
+
+ mcmd = mstb->mcmd;
+ TRACE_MGMT_DBG("mcmd %p, mcmd->cmd_done_wait_count %d",
+ mcmd, mcmd->cmd_done_wait_count);
+
+ mcmd->cmd_done_wait_count--;
+ if (mcmd->cmd_done_wait_count > 0) {
+ TRACE_MGMT_DBG("cmd_done_wait_count(%d) not 0, "
+ "skipping", mcmd->cmd_done_wait_count);
+ continue;
+ }
+
+ if (mcmd->completed) {
+ BUG_ON(mcmd->affected_cmds_done_called);
+ mcmd->completed = 0;
+ mcmd->state = SCST_MCMD_STATE_POST_AFFECTED_CMDS_DONE;
+ TRACE_MGMT_DBG("Adding mgmt cmd %p to active mgmt cmd "
+ "list", mcmd);
+ list_add_tail(&mcmd->mgmt_cmd_list_entry,
+ &scst_active_mgmt_cmd_list);
+ wake = 1;
+ }
+ }
+
+ spin_unlock_irqrestore(&scst_mcmd_lock, flags);
+
+ if (wake)
+ wake_up(&scst_mgmt_cmd_list_waitQ);
+ return;
+}
+
+/* Called under scst_mcmd_lock and IRQs disabled */
+static int __scst_dec_finish_wait_count(struct scst_mgmt_cmd *mcmd, bool *wake)
+{
+
+ mcmd->cmd_finish_wait_count--;
+ if (mcmd->cmd_finish_wait_count > 0) {
+ TRACE_MGMT_DBG("cmd_finish_wait_count(%d) not 0, "
+ "skipping", mcmd->cmd_finish_wait_count);
+ goto out;
+ }
+
+ if (mcmd->completed) {
+ mcmd->state = SCST_MCMD_STATE_DONE;
+ TRACE_MGMT_DBG("Adding mgmt cmd %p to active mgmt cmd "
+ "list", mcmd);
+ list_add_tail(&mcmd->mgmt_cmd_list_entry,
+ &scst_active_mgmt_cmd_list);
+ *wake = true;
+ }
+
+out:
+ return mcmd->cmd_finish_wait_count;
+}
+
+/**
+ * scst_prepare_async_mcmd() - prepare async management command
+ *
+ * Notifies SCST that management command is going to be async, i.e.
+ * will be completed in another context.
+ *
+ * No SCST locks supposed to be held on entrance.
+ */
+void scst_prepare_async_mcmd(struct scst_mgmt_cmd *mcmd)
+{
+ unsigned long flags;
+
+ TRACE_MGMT_DBG("Preparing mcmd %p for async execution "
+ "(cmd_finish_wait_count %d)", mcmd,
+ mcmd->cmd_finish_wait_count);
+
+ spin_lock_irqsave(&scst_mcmd_lock, flags);
+ mcmd->cmd_finish_wait_count++;
+ spin_unlock_irqrestore(&scst_mcmd_lock, flags);
+ return;
+}
+EXPORT_SYMBOL_GPL(scst_prepare_async_mcmd);
+
+/**
+ * scst_async_mcmd_completed() - async management command completed
+ *
+ * Notifies SCST that async management command, prepared by
+ * scst_prepare_async_mcmd(), completed.
+ *
+ * No SCST locks supposed to be held on entrance.
+ */
+void scst_async_mcmd_completed(struct scst_mgmt_cmd *mcmd, int status)
+{
+ unsigned long flags;
+ bool wake = false;
+
+ TRACE_MGMT_DBG("Async mcmd %p completed (status %d)", mcmd, status);
+
+ spin_lock_irqsave(&scst_mcmd_lock, flags);
+
+ if (status != SCST_MGMT_STATUS_SUCCESS)
+ mcmd->status = status;
+
+ __scst_dec_finish_wait_count(mcmd, &wake);
+
+ spin_unlock_irqrestore(&scst_mcmd_lock, flags);
+
+ if (wake)
+ wake_up(&scst_mgmt_cmd_list_waitQ);
+ return;
+}
+EXPORT_SYMBOL_GPL(scst_async_mcmd_completed);
+
+/* No locks */
+static void scst_finish_cmd_mgmt(struct scst_cmd *cmd)
+{
+ struct scst_mgmt_cmd_stub *mstb, *t;
+ bool wake = false;
+ unsigned long flags;
+
+ TRACE_MGMT_DBG("cmd %p finished (tag %llu)",
+ cmd, (long long unsigned int)cmd->tag);
+
+ spin_lock_irqsave(&scst_mcmd_lock, flags);
+
+ list_for_each_entry_safe(mstb, t, &cmd->mgmt_cmd_list,
+ cmd_mgmt_cmd_list_entry) {
+ struct scst_mgmt_cmd *mcmd = mstb->mcmd;
+
+ TRACE_MGMT_DBG("mcmd %p, mcmd->cmd_finish_wait_count %d",
+ mcmd, mcmd->cmd_finish_wait_count);
+
+ list_del(&mstb->cmd_mgmt_cmd_list_entry);
+ mempool_free(mstb, scst_mgmt_stub_mempool);
+
+ if (cmd->completed)
+ mcmd->completed_cmd_count++;
+
+ if (__scst_dec_finish_wait_count(mcmd, &wake) > 0) {
+ TRACE_MGMT_DBG("cmd_finish_wait_count(%d) not 0, "
+ "skipping", mcmd->cmd_finish_wait_count);
+ continue;
+ }
+ }
+
+ spin_unlock_irqrestore(&scst_mcmd_lock, flags);
+
+ if (wake)
+ wake_up(&scst_mgmt_cmd_list_waitQ);
+ return;
+}
+
+static int scst_call_dev_task_mgmt_fn(struct scst_mgmt_cmd *mcmd,
+ struct scst_tgt_dev *tgt_dev, int set_status)
+{
+ int res = SCST_DEV_TM_NOT_COMPLETED;
+ struct scst_dev_type *h = tgt_dev->dev->handler;
+
+ if (h->task_mgmt_fn) {
+ TRACE_MGMT_DBG("Calling dev handler %s task_mgmt_fn(fn=%d)",
+ h->name, mcmd->fn);
+ EXTRACHECKS_BUG_ON(in_irq() || irqs_disabled());
+ res = h->task_mgmt_fn(mcmd, tgt_dev);
+ TRACE_MGMT_DBG("Dev handler %s task_mgmt_fn() returned %d",
+ h->name, res);
+ if (set_status && (res != SCST_DEV_TM_NOT_COMPLETED))
+ mcmd->status = res;
+ }
+ return res;
+}
+
+static inline int scst_is_strict_mgmt_fn(int mgmt_fn)
+{
+ switch (mgmt_fn) {
+#ifdef CONFIG_SCST_ABORT_CONSIDER_FINISHED_TASKS_AS_NOT_EXISTING
+ case SCST_ABORT_TASK:
+#endif
+#if 0
+ case SCST_ABORT_TASK_SET:
+ case SCST_CLEAR_TASK_SET:
+#endif
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+/* Might be called under sess_list_lock and IRQ off + BHs also off */
+void scst_abort_cmd(struct scst_cmd *cmd, struct scst_mgmt_cmd *mcmd,
+ int other_ini, int call_dev_task_mgmt_fn)
+{
+ unsigned long flags;
+ static DEFINE_SPINLOCK(other_ini_lock);
+
+ TRACE(TRACE_MGMT, "Aborting cmd %p (tag %llu, op %x)",
+ cmd, (long long unsigned int)cmd->tag, cmd->cdb[0]);
+
+ /* To protect from concurrent aborts */
+ spin_lock_irqsave(&other_ini_lock, flags);
+
+ if (other_ini) {
+ struct scst_device *dev = NULL;
+
+ /* Might be necessary if command aborted several times */
+ if (!test_bit(SCST_CMD_ABORTED, &cmd->cmd_flags))
+ set_bit(SCST_CMD_ABORTED_OTHER, &cmd->cmd_flags);
+
+ /* Necessary for scst_xmit_process_aborted_cmd */
+ if (cmd->dev != NULL)
+ dev = cmd->dev;
+ else if ((mcmd != NULL) && (mcmd->mcmd_tgt_dev != NULL))
+ dev = mcmd->mcmd_tgt_dev->dev;
+
+ if (dev != NULL) {
+ if (dev->tas)
+ set_bit(SCST_CMD_DEVICE_TAS, &cmd->cmd_flags);
+ } else
+ PRINT_WARNING("Abort cmd %p from other initiator, but "
+ "neither cmd, nor mcmd %p have tgt_dev set, so "
+ "TAS information can be lost", cmd, mcmd);
+ } else {
+ /* Might be necessary if command aborted several times */
+ clear_bit(SCST_CMD_ABORTED_OTHER, &cmd->cmd_flags);
+ }
+
+ set_bit(SCST_CMD_ABORTED, &cmd->cmd_flags);
+
+ spin_unlock_irqrestore(&other_ini_lock, flags);
+
+ /*
+ * To sync with cmd->finished/done set in
+ * scst_finish_cmd()/scst_pre_xmit_response()
+ */
+ smp_mb__after_set_bit();
+
+ if (cmd->tgt_dev == NULL) {
+ spin_lock_irqsave(&scst_init_lock, flags);
+ scst_init_poll_cnt++;
+ spin_unlock_irqrestore(&scst_init_lock, flags);
+ wake_up(&scst_init_cmd_list_waitQ);
+ }
+
+ if (call_dev_task_mgmt_fn && (cmd->tgt_dev != NULL)) {
+ EXTRACHECKS_BUG_ON(irqs_disabled());
+ scst_call_dev_task_mgmt_fn(mcmd, cmd->tgt_dev, 1);
+ }
+
+ spin_lock_irqsave(&scst_mcmd_lock, flags);
+ if ((mcmd != NULL) && !cmd->finished) {
+ struct scst_mgmt_cmd_stub *mstb;
+
+ mstb = mempool_alloc(scst_mgmt_stub_mempool, GFP_ATOMIC);
+ if (mstb == NULL) {
+ PRINT_CRIT_ERROR("Allocation of management command "
+ "stub failed (mcmd %p, cmd %p)", mcmd, cmd);
+ goto unlock;
+ }
+ memset(mstb, 0, sizeof(*mstb));
+
+ mstb->mcmd = mcmd;
+
+ /*
+ * cmd can't die here or sess_list_lock already taken and
+ * cmd is in the sess list
+ */
+ list_add_tail(&mstb->cmd_mgmt_cmd_list_entry,
+ &cmd->mgmt_cmd_list);
+
+ /*
+ * Delay the response until the command's finish in order to
+ * guarantee that "no further responses from the task are sent
+ * to the SCSI initiator port" after response from the TM
+ * function is sent (SAM). Plus, we must wait here to be sure
+ * that we won't receive double commands with the same tag.
+ * Moreover, if we don't wait here, we might have a possibility
+ * for data corruption, when aborted and reported as completed
+ * command actually gets executed *after* new commands sent
+ * after this TM command completed.
+ */
+ TRACE_MGMT_DBG("cmd %p (tag %llu, sn %u) being "
+ "executed/xmitted (state %d, op %x, proc time %ld "
+ "sec., timeout %d sec.), deferring ABORT...", cmd,
+ (long long unsigned int)cmd->tag, cmd->sn, cmd->state,
+ cmd->cdb[0], (long)(jiffies - cmd->start_time) / HZ,
+ cmd->timeout / HZ);
+
+ mcmd->cmd_finish_wait_count++;
+
+ if (cmd->sent_for_exec && !cmd->done) {
+ TRACE_MGMT_DBG("cmd %p (tag %llu) is being executed "
+ "and not done yet", cmd,
+ (long long unsigned int)cmd->tag);
+ mstb->done_counted = 1;
+ mcmd->cmd_done_wait_count++;
+ }
+ }
+unlock:
+ spin_unlock_irqrestore(&scst_mcmd_lock, flags);
+
+ tm_dbg_release_cmd(cmd);
+ return;
+}
+
+/* No locks */
+static int scst_set_mcmd_next_state(struct scst_mgmt_cmd *mcmd)
+{
+ int res;
+
+ spin_lock_irq(&scst_mcmd_lock);
+
+ if (mcmd->cmd_finish_wait_count == 0) {
+ if (!mcmd->affected_cmds_done_called)
+ mcmd->state = SCST_MCMD_STATE_POST_AFFECTED_CMDS_DONE;
+ else
+ mcmd->state = SCST_MCMD_STATE_DONE;
+ res = 0;
+ } else if ((mcmd->cmd_done_wait_count == 0) &&
+ (!mcmd->affected_cmds_done_called)) {
+ mcmd->state = SCST_MCMD_STATE_POST_AFFECTED_CMDS_DONE;
+ res = 0;
+ goto out_unlock;
+ } else {
+ TRACE_MGMT_DBG("cmd_finish_wait_count(%d) not 0, preparing to "
+ "wait", mcmd->cmd_finish_wait_count);
+ mcmd->state = SCST_MCMD_STATE_EXECUTING;
+ res = -1;
+ }
+
+ mcmd->completed = 1;
+
+out_unlock:
+ spin_unlock_irq(&scst_mcmd_lock);
+ return res;
+}
+
+static bool __scst_check_unblock_aborted_cmd(struct scst_cmd *cmd,
+ struct list_head *list_entry)
+{
+ bool res;
+ if (test_bit(SCST_CMD_ABORTED, &cmd->cmd_flags)) {
+ list_del(list_entry);
+ spin_lock(&cmd->cmd_threads->cmd_list_lock);
+ list_add_tail(&cmd->cmd_list_entry,
+ &cmd->cmd_threads->active_cmd_list);
+ wake_up(&cmd->cmd_threads->cmd_list_waitQ);
+ spin_unlock(&cmd->cmd_threads->cmd_list_lock);
+ res = 1;
+ } else
+ res = 0;
+ return res;
+}
+
+static void scst_unblock_aborted_cmds(int scst_mutex_held)
+{
+ struct scst_device *dev;
+
+ if (!scst_mutex_held)
+ mutex_lock(&scst_mutex);
+
+ list_for_each_entry(dev, &scst_dev_list, dev_list_entry) {
+ struct scst_cmd *cmd, *tcmd;
+ struct scst_tgt_dev *tgt_dev;
+ spin_lock_bh(&dev->dev_lock);
+ local_irq_disable();
+ list_for_each_entry_safe(cmd, tcmd, &dev->blocked_cmd_list,
+ blocked_cmd_list_entry) {
+ if (__scst_check_unblock_aborted_cmd(cmd,
+ &cmd->blocked_cmd_list_entry)) {
+ TRACE_MGMT_DBG("Unblock aborted blocked cmd %p",
+ cmd);
+ }
+ }
+ local_irq_enable();
+ spin_unlock_bh(&dev->dev_lock);
+
+ local_irq_disable();
+ list_for_each_entry(tgt_dev, &dev->dev_tgt_dev_list,
+ dev_tgt_dev_list_entry) {
+ spin_lock(&tgt_dev->sn_lock);
+ list_for_each_entry_safe(cmd, tcmd,
+ &tgt_dev->deferred_cmd_list,
+ sn_cmd_list_entry) {
+ if (__scst_check_unblock_aborted_cmd(cmd,
+ &cmd->sn_cmd_list_entry)) {
+ TRACE_MGMT_DBG("Unblocked aborted SN "
+ "cmd %p (sn %u)",
+ cmd, cmd->sn);
+ tgt_dev->def_cmd_count--;
+ }
+ }
+ spin_unlock(&tgt_dev->sn_lock);
+ }
+ local_irq_enable();
+ }
+
+ if (!scst_mutex_held)
+ mutex_unlock(&scst_mutex);
+ return;
+}
+
+static void __scst_abort_task_set(struct scst_mgmt_cmd *mcmd,
+ struct scst_tgt_dev *tgt_dev)
+{
+ struct scst_cmd *cmd;
+ struct scst_session *sess = tgt_dev->sess;
+
+ spin_lock_irq(&sess->sess_list_lock);
+
+ TRACE_DBG("Searching in sess cmd list (sess=%p)", sess);
+ list_for_each_entry(cmd, &sess->sess_cmd_list,
+ sess_cmd_list_entry) {
+ if ((cmd->tgt_dev == tgt_dev) ||
+ ((cmd->tgt_dev == NULL) &&
+ (cmd->lun == tgt_dev->lun))) {
+ if (mcmd->cmd_sn_set) {
+ BUG_ON(!cmd->tgt_sn_set);
+ if (scst_sn_before(mcmd->cmd_sn, cmd->tgt_sn) ||
+ (mcmd->cmd_sn == cmd->tgt_sn))
+ continue;
+ }
+ scst_abort_cmd(cmd, mcmd, 0, 0);
+ }
+ }
+ spin_unlock_irq(&sess->sess_list_lock);
+ return;
+}
+
+/* Returns 0 if the command processing should be continued, <0 otherwise */
+static int scst_abort_task_set(struct scst_mgmt_cmd *mcmd)
+{
+ int res;
+ struct scst_tgt_dev *tgt_dev = mcmd->mcmd_tgt_dev;
+
+ TRACE(TRACE_MGMT, "Aborting task set (lun=%lld, mcmd=%p)",
+ (long long unsigned int)tgt_dev->lun, mcmd);
+
+ __scst_abort_task_set(mcmd, tgt_dev);
+
+ tm_dbg_task_mgmt(mcmd->mcmd_tgt_dev->dev, "ABORT TASK SET", 0);
+
+ scst_unblock_aborted_cmds(0);
+
+ scst_call_dev_task_mgmt_fn(mcmd, tgt_dev, 0);
+
+ res = scst_set_mcmd_next_state(mcmd);
+ return res;
+}
+
+static int scst_is_cmd_belongs_to_dev(struct scst_cmd *cmd,
+ struct scst_device *dev)
+{
+ struct scst_tgt_dev *tgt_dev = NULL;
+ struct list_head *sess_tgt_dev_list_head;
+ int res = 0;
+
+ TRACE_DBG("Finding match for dev %p and cmd %p (lun %lld)", dev, cmd,
+ (long long unsigned int)cmd->lun);
+
+ sess_tgt_dev_list_head =
+ &cmd->sess->sess_tgt_dev_list_hash[HASH_VAL(cmd->lun)];
+ list_for_each_entry(tgt_dev, sess_tgt_dev_list_head,
+ sess_tgt_dev_list_entry) {
+ if (tgt_dev->lun == cmd->lun) {
+ TRACE_DBG("dev %p found", tgt_dev->dev);
+ res = (tgt_dev->dev == dev);
+ goto out;
+ }
+ }
+
+out:
+ return res;
+}
+
+/* Returns 0 if the command processing should be continued, <0 otherwise */
+static int scst_clear_task_set(struct scst_mgmt_cmd *mcmd)
+{
+ int res;
+ struct scst_device *dev = mcmd->mcmd_tgt_dev->dev;
+ struct scst_tgt_dev *tgt_dev;
+ LIST_HEAD(UA_tgt_devs);
+
+ TRACE(TRACE_MGMT, "Clearing task set (lun=%lld, mcmd=%p)",
+ (long long unsigned int)mcmd->lun, mcmd);
+
+#if 0 /* we are SAM-3 */
+ /*
+ * When a logical unit is aborting one or more tasks from a SCSI
+ * initiator port with the TASK ABORTED status it should complete all
+ * of those tasks before entering additional tasks from that SCSI
+ * initiator port into the task set - SAM2
+ */
+ mcmd->needs_unblocking = 1;
+ spin_lock_bh(&dev->dev_lock);
+ __scst_block_dev(dev);
+ spin_unlock_bh(&dev->dev_lock);
+#endif
+
+ __scst_abort_task_set(mcmd, mcmd->mcmd_tgt_dev);
+
+ mutex_lock(&scst_mutex);
+
+ list_for_each_entry(tgt_dev, &dev->dev_tgt_dev_list,
+ dev_tgt_dev_list_entry) {
+ struct scst_session *sess = tgt_dev->sess;
+ struct scst_cmd *cmd;
+ int aborted = 0;
+
+ if (tgt_dev == mcmd->mcmd_tgt_dev)
+ continue;
+
+ spin_lock_irq(&sess->sess_list_lock);
+
+ TRACE_DBG("Searching in sess cmd list (sess=%p)", sess);
+ list_for_each_entry(cmd, &sess->sess_cmd_list,
+ sess_cmd_list_entry) {
+ if ((cmd->dev == dev) ||
+ ((cmd->dev == NULL) &&
+ scst_is_cmd_belongs_to_dev(cmd, dev))) {
+ scst_abort_cmd(cmd, mcmd, 1, 0);
+ aborted = 1;
+ }
+ }
+ spin_unlock_irq(&sess->sess_list_lock);
+
+ if (aborted)
+ list_add_tail(&tgt_dev->extra_tgt_dev_list_entry,
+ &UA_tgt_devs);
+ }
+
+ tm_dbg_task_mgmt(mcmd->mcmd_tgt_dev->dev, "CLEAR TASK SET", 0);
+
+ scst_unblock_aborted_cmds(1);
+
+ mutex_unlock(&scst_mutex);
+
+ if (!dev->tas) {
+ uint8_t sense_buffer[SCST_STANDARD_SENSE_LEN];
+ int sl;
+
+ sl = scst_set_sense(sense_buffer, sizeof(sense_buffer),
+ dev->d_sense,
+ SCST_LOAD_SENSE(scst_sense_cleared_by_another_ini_UA));
+
+ list_for_each_entry(tgt_dev, &UA_tgt_devs,
+ extra_tgt_dev_list_entry) {
+ scst_check_set_UA(tgt_dev, sense_buffer, sl, 0);
+ }
+ }
+
+ scst_call_dev_task_mgmt_fn(mcmd, mcmd->mcmd_tgt_dev, 0);
+
+ res = scst_set_mcmd_next_state(mcmd);
+ return res;
+}
+
+/* Returns 0 if the command processing should be continued,
+ * >0, if it should be requeued, <0 otherwise */
+static int scst_mgmt_cmd_init(struct scst_mgmt_cmd *mcmd)
+{
+ int res = 0, rc;
+
+ switch (mcmd->fn) {
+ case SCST_ABORT_TASK:
+ {
+ struct scst_session *sess = mcmd->sess;
+ struct scst_cmd *cmd;
+
+ spin_lock_irq(&sess->sess_list_lock);
+ cmd = __scst_find_cmd_by_tag(sess, mcmd->tag, true);
+ if (cmd == NULL) {
+ TRACE_MGMT_DBG("ABORT TASK: command "
+ "for tag %llu not found",
+ (long long unsigned int)mcmd->tag);
+ mcmd->status = SCST_MGMT_STATUS_TASK_NOT_EXIST;
+ mcmd->state = SCST_MCMD_STATE_DONE;
+ spin_unlock_irq(&sess->sess_list_lock);
+ goto out;
+ }
+ __scst_cmd_get(cmd);
+ spin_unlock_irq(&sess->sess_list_lock);
+ TRACE_MGMT_DBG("Cmd %p for tag %llu (sn %d, set %d, "
+ "queue_type %x) found, aborting it",
+ cmd, (long long unsigned int)mcmd->tag,
+ cmd->sn, cmd->sn_set, cmd->queue_type);
+ mcmd->cmd_to_abort = cmd;
+ if (mcmd->lun_set && (mcmd->lun != cmd->lun)) {
+ PRINT_ERROR("ABORT TASK: LUN mismatch: mcmd LUN %llx, "
+ "cmd LUN %llx, cmd tag %llu",
+ (long long unsigned int)mcmd->lun,
+ (long long unsigned int)cmd->lun,
+ (long long unsigned int)mcmd->tag);
+ mcmd->status = SCST_MGMT_STATUS_REJECTED;
+ } else if (mcmd->cmd_sn_set &&
+ (scst_sn_before(mcmd->cmd_sn, cmd->tgt_sn) ||
+ (mcmd->cmd_sn == cmd->tgt_sn))) {
+ PRINT_ERROR("ABORT TASK: SN mismatch: mcmd SN %x, "
+ "cmd SN %x, cmd tag %llu", mcmd->cmd_sn,
+ cmd->tgt_sn, (long long unsigned int)mcmd->tag);
+ mcmd->status = SCST_MGMT_STATUS_REJECTED;
+ } else {
+ scst_abort_cmd(cmd, mcmd, 0, 1);
+ scst_unblock_aborted_cmds(0);
+ }
+ res = scst_set_mcmd_next_state(mcmd);
+ mcmd->cmd_to_abort = NULL; /* just in case */
+ __scst_cmd_put(cmd);
+ break;
+ }
+
+ case SCST_TARGET_RESET:
+ case SCST_NEXUS_LOSS_SESS:
+ case SCST_ABORT_ALL_TASKS_SESS:
+ case SCST_NEXUS_LOSS:
+ case SCST_ABORT_ALL_TASKS:
+ case SCST_UNREG_SESS_TM:
+ mcmd->state = SCST_MCMD_STATE_READY;
+ break;
+
+ case SCST_ABORT_TASK_SET:
+ case SCST_CLEAR_ACA:
+ case SCST_CLEAR_TASK_SET:
+ case SCST_LUN_RESET:
+ rc = scst_mgmt_translate_lun(mcmd);
+ if (rc == 0)
+ mcmd->state = SCST_MCMD_STATE_READY;
+ else if (rc < 0) {
+ PRINT_ERROR("Corresponding device for LUN %lld not "
+ "found", (long long unsigned int)mcmd->lun);
+ mcmd->status = SCST_MGMT_STATUS_LUN_NOT_EXIST;
+ mcmd->state = SCST_MCMD_STATE_DONE;
+ } else
+ res = rc;
+ break;
+
+ default:
+ BUG();
+ }
+
+out:
+ return res;
+}
+
+/* Returns 0 if the command processing should be continued, <0 otherwise */
+static int scst_target_reset(struct scst_mgmt_cmd *mcmd)
+{
+ int res, rc;
+ struct scst_device *dev;
+ struct scst_acg *acg = mcmd->sess->acg;
+ struct scst_acg_dev *acg_dev;
+ int cont, c;
+ LIST_HEAD(host_devs);
+
+ TRACE(TRACE_MGMT, "Target reset (mcmd %p, cmd count %d)",
+ mcmd, atomic_read(&mcmd->sess->sess_cmd_count));
+
+ mcmd->needs_unblocking = 1;
+
+ mutex_lock(&scst_mutex);
+
+ list_for_each_entry(acg_dev, &acg->acg_dev_list, acg_dev_list_entry) {
+ struct scst_device *d;
+ struct scst_tgt_dev *tgt_dev;
+ int found = 0;
+
+ dev = acg_dev->dev;
+
+ spin_lock_bh(&dev->dev_lock);
+ __scst_block_dev(dev);
+ scst_process_reset(dev, mcmd->sess, NULL, mcmd, true);
+ spin_unlock_bh(&dev->dev_lock);
+
+ cont = 0;
+ c = 0;
+ list_for_each_entry(tgt_dev, &dev->dev_tgt_dev_list,
+ dev_tgt_dev_list_entry) {
+ cont = 1;
+ if (mcmd->sess == tgt_dev->sess) {
+ rc = scst_call_dev_task_mgmt_fn(mcmd,
+ tgt_dev, 0);
+ if (rc == SCST_DEV_TM_NOT_COMPLETED)
+ c = 1;
+ else if ((rc < 0) &&
+ (mcmd->status == SCST_MGMT_STATUS_SUCCESS))
+ mcmd->status = rc;
+ break;
+ }
+ }
+ if (cont && !c)
+ continue;
+
+ if (dev->scsi_dev == NULL)
+ continue;
+
+ list_for_each_entry(d, &host_devs, tm_dev_list_entry) {
+ if (dev->scsi_dev->host->host_no ==
+ d->scsi_dev->host->host_no) {
+ found = 1;
+ break;
+ }
+ }
+ if (!found)
+ list_add_tail(&dev->tm_dev_list_entry, &host_devs);
+
+ tm_dbg_task_mgmt(dev, "TARGET RESET", 0);
+ }
+
+ scst_unblock_aborted_cmds(1);
+
+ /*
+ * We suppose here that for all commands that already on devices
+ * on/after scsi_reset_provider() completion callbacks will be called.
+ */
+
+ list_for_each_entry(dev, &host_devs, tm_dev_list_entry) {
+ /* dev->scsi_dev must be non-NULL here */
+ TRACE(TRACE_MGMT, "Resetting host %d bus ",
+ dev->scsi_dev->host->host_no);
+ rc = scsi_reset_provider(dev->scsi_dev, SCSI_TRY_RESET_TARGET);
+ TRACE(TRACE_MGMT, "Result of host %d target reset: %s",
+ dev->scsi_dev->host->host_no,
+ (rc == SUCCESS) ? "SUCCESS" : "FAILED");
+#if 0
+ if ((rc != SUCCESS) &&
+ (mcmd->status == SCST_MGMT_STATUS_SUCCESS)) {
+ /*
+ * SCSI_TRY_RESET_BUS is also done by
+ * scsi_reset_provider()
+ */
+ mcmd->status = SCST_MGMT_STATUS_FAILED;
+ }
+#else
+ /*
+ * scsi_reset_provider() returns very weird status, so let's
+ * always succeed
+ */
+#endif
+ }
+
+ list_for_each_entry(acg_dev, &acg->acg_dev_list, acg_dev_list_entry) {
+ dev = acg_dev->dev;
+ if (dev->scsi_dev != NULL)
+ dev->scsi_dev->was_reset = 0;
+ }
+
+ mutex_unlock(&scst_mutex);
+
+ res = scst_set_mcmd_next_state(mcmd);
+ return res;
+}
+
+/* Returns 0 if the command processing should be continued, <0 otherwise */
+static int scst_lun_reset(struct scst_mgmt_cmd *mcmd)
+{
+ int res, rc;
+ struct scst_tgt_dev *tgt_dev = mcmd->mcmd_tgt_dev;
+ struct scst_device *dev = tgt_dev->dev;
+
+ TRACE(TRACE_MGMT, "Resetting LUN %lld (mcmd %p)",
+ (long long unsigned int)tgt_dev->lun, mcmd);
+
+ mcmd->needs_unblocking = 1;
+
+ spin_lock_bh(&dev->dev_lock);
+ __scst_block_dev(dev);
+ scst_process_reset(dev, mcmd->sess, NULL, mcmd, true);
+ spin_unlock_bh(&dev->dev_lock);
+
+ rc = scst_call_dev_task_mgmt_fn(mcmd, tgt_dev, 1);
+ if (rc != SCST_DEV_TM_NOT_COMPLETED)
+ goto out_tm_dbg;
+
+ if (dev->scsi_dev != NULL) {
+ TRACE(TRACE_MGMT, "Resetting host %d bus ",
+ dev->scsi_dev->host->host_no);
+ rc = scsi_reset_provider(dev->scsi_dev, SCSI_TRY_RESET_DEVICE);
+#if 0
+ if (rc != SUCCESS && mcmd->status == SCST_MGMT_STATUS_SUCCESS)
+ mcmd->status = SCST_MGMT_STATUS_FAILED;
+#else
+ /*
+ * scsi_reset_provider() returns very weird status, so let's
+ * always succeed
+ */
+#endif
+ dev->scsi_dev->was_reset = 0;
+ }
+
+ scst_unblock_aborted_cmds(0);
+
+out_tm_dbg:
+ tm_dbg_task_mgmt(mcmd->mcmd_tgt_dev->dev, "LUN RESET", 0);
+
+ res = scst_set_mcmd_next_state(mcmd);
+ return res;
+}
+
+/* scst_mutex supposed to be held */
+static void scst_do_nexus_loss_sess(struct scst_mgmt_cmd *mcmd)
+{
+ int i;
+ struct scst_session *sess = mcmd->sess;
+ struct scst_tgt_dev *tgt_dev;
+
+ for (i = 0; i < TGT_DEV_HASH_SIZE; i++) {
+ struct list_head *sess_tgt_dev_list_head =
+ &sess->sess_tgt_dev_list_hash[i];
+ list_for_each_entry(tgt_dev, sess_tgt_dev_list_head,
+ sess_tgt_dev_list_entry) {
+ scst_nexus_loss(tgt_dev,
+ (mcmd->fn != SCST_UNREG_SESS_TM));
+ }
+ }
+ return;
+}
+
+/* Returns 0 if the command processing should be continued, <0 otherwise */
+static int scst_abort_all_nexus_loss_sess(struct scst_mgmt_cmd *mcmd,
+ int nexus_loss)
+{
+ int res;
+ int i;
+ struct scst_session *sess = mcmd->sess;
+ struct scst_tgt_dev *tgt_dev;
+
+ if (nexus_loss) {
+ TRACE_MGMT_DBG("Nexus loss for sess %p (mcmd %p)",
+ sess, mcmd);
+ } else {
+ TRACE_MGMT_DBG("Aborting all from sess %p (mcmd %p)",
+ sess, mcmd);
+ }
+
+ mutex_lock(&scst_mutex);
+
+ for (i = 0; i < TGT_DEV_HASH_SIZE; i++) {
+ struct list_head *sess_tgt_dev_list_head =
+ &sess->sess_tgt_dev_list_hash[i];
+ list_for_each_entry(tgt_dev, sess_tgt_dev_list_head,
+ sess_tgt_dev_list_entry) {
+ int rc;
+
+ __scst_abort_task_set(mcmd, tgt_dev);
+
+ rc = scst_call_dev_task_mgmt_fn(mcmd, tgt_dev, 0);
+ if (rc < 0 && mcmd->status == SCST_MGMT_STATUS_SUCCESS)
+ mcmd->status = rc;
+
+ tm_dbg_task_mgmt(tgt_dev->dev, "NEXUS LOSS SESS or "
+ "ABORT ALL SESS or UNREG SESS",
+ (mcmd->fn == SCST_UNREG_SESS_TM));
+ }
+ }
+
+ scst_unblock_aborted_cmds(1);
+
+ mutex_unlock(&scst_mutex);
+
+ res = scst_set_mcmd_next_state(mcmd);
+ return res;
+}
+
+/* scst_mutex supposed to be held */
+static void scst_do_nexus_loss_tgt(struct scst_mgmt_cmd *mcmd)
+{
+ int i;
+ struct scst_tgt *tgt = mcmd->sess->tgt;
+ struct scst_session *sess;
+
+ list_for_each_entry(sess, &tgt->sess_list, sess_list_entry) {
+ for (i = 0; i < TGT_DEV_HASH_SIZE; i++) {
+ struct list_head *sess_tgt_dev_list_head =
+ &sess->sess_tgt_dev_list_hash[i];
+ struct scst_tgt_dev *tgt_dev;
+ list_for_each_entry(tgt_dev, sess_tgt_dev_list_head,
+ sess_tgt_dev_list_entry) {
+ scst_nexus_loss(tgt_dev, true);
+ }
+ }
+ }
+ return;
+}
+
+static int scst_abort_all_nexus_loss_tgt(struct scst_mgmt_cmd *mcmd,
+ int nexus_loss)
+{
+ int res;
+ int i;
+ struct scst_tgt *tgt = mcmd->sess->tgt;
+ struct scst_session *sess;
+
+ if (nexus_loss) {
+ TRACE_MGMT_DBG("I_T Nexus loss (tgt %p, mcmd %p)",
+ tgt, mcmd);
+ } else {
+ TRACE_MGMT_DBG("Aborting all from tgt %p (mcmd %p)",
+ tgt, mcmd);
+ }
+
+ mutex_lock(&scst_mutex);
+
+ list_for_each_entry(sess, &tgt->sess_list, sess_list_entry) {
+ for (i = 0; i < TGT_DEV_HASH_SIZE; i++) {
+ struct list_head *sess_tgt_dev_list_head =
+ &sess->sess_tgt_dev_list_hash[i];
+ struct scst_tgt_dev *tgt_dev;
+ list_for_each_entry(tgt_dev, sess_tgt_dev_list_head,
+ sess_tgt_dev_list_entry) {
+ int rc;
+
+ __scst_abort_task_set(mcmd, tgt_dev);
+
+ if (nexus_loss)
+ scst_nexus_loss(tgt_dev, true);
+
+ if (mcmd->sess == tgt_dev->sess) {
+ rc = scst_call_dev_task_mgmt_fn(
+ mcmd, tgt_dev, 0);
+ if ((rc < 0) &&
+ (mcmd->status == SCST_MGMT_STATUS_SUCCESS))
+ mcmd->status = rc;
+ }
+
+ tm_dbg_task_mgmt(tgt_dev->dev, "NEXUS LOSS or "
+ "ABORT ALL", 0);
+ }
+ }
+ }
+
+ scst_unblock_aborted_cmds(1);
+
+ mutex_unlock(&scst_mutex);
+
+ res = scst_set_mcmd_next_state(mcmd);
+ return res;
+}
+
+/* Returns 0 if the command processing should be continued, <0 otherwise */
+static int scst_mgmt_cmd_exec(struct scst_mgmt_cmd *mcmd)
+{
+ int res = 0;
+
+ mcmd->status = SCST_MGMT_STATUS_SUCCESS;
+
+ switch (mcmd->fn) {
+ case SCST_ABORT_TASK_SET:
+ res = scst_abort_task_set(mcmd);
+ break;
+
+ case SCST_CLEAR_TASK_SET:
+ if (mcmd->mcmd_tgt_dev->dev->tst ==
+ SCST_CONTR_MODE_SEP_TASK_SETS)
+ res = scst_abort_task_set(mcmd);
+ else
+ res = scst_clear_task_set(mcmd);
+ break;
+
+ case SCST_LUN_RESET:
+ res = scst_lun_reset(mcmd);
+ break;
+
+ case SCST_TARGET_RESET:
+ res = scst_target_reset(mcmd);
+ break;
+
+ case SCST_ABORT_ALL_TASKS_SESS:
+ res = scst_abort_all_nexus_loss_sess(mcmd, 0);
+ break;
+
+ case SCST_NEXUS_LOSS_SESS:
+ case SCST_UNREG_SESS_TM:
+ res = scst_abort_all_nexus_loss_sess(mcmd, 1);
+ break;
+
+ case SCST_ABORT_ALL_TASKS:
+ res = scst_abort_all_nexus_loss_tgt(mcmd, 0);
+ break;
+
+ case SCST_NEXUS_LOSS:
+ res = scst_abort_all_nexus_loss_tgt(mcmd, 1);
+ break;
+
+ case SCST_CLEAR_ACA:
+ if (scst_call_dev_task_mgmt_fn(mcmd, mcmd->mcmd_tgt_dev, 1) ==
+ SCST_DEV_TM_NOT_COMPLETED) {
+ mcmd->status = SCST_MGMT_STATUS_FN_NOT_SUPPORTED;
+ /* Nothing to do (yet) */
+ }
+ goto out_done;
+
+ default:
+ PRINT_ERROR("Unknown task management function %d", mcmd->fn);
+ mcmd->status = SCST_MGMT_STATUS_REJECTED;
+ goto out_done;
+ }
+
+out:
+ return res;
+
+out_done:
+ mcmd->state = SCST_MCMD_STATE_DONE;
+ goto out;
+}
+
+static void scst_call_task_mgmt_affected_cmds_done(struct scst_mgmt_cmd *mcmd)
+{
+ struct scst_session *sess = mcmd->sess;
+
+ if ((sess->tgt->tgtt->task_mgmt_affected_cmds_done != NULL) &&
+ (mcmd->fn != SCST_UNREG_SESS_TM)) {
+ TRACE_DBG("Calling target %s task_mgmt_affected_cmds_done(%p)",
+ sess->tgt->tgtt->name, sess);
+ sess->tgt->tgtt->task_mgmt_affected_cmds_done(mcmd);
+ TRACE_MGMT_DBG("Target's %s task_mgmt_affected_cmds_done() "
+ "returned", sess->tgt->tgtt->name);
+ }
+ return;
+}
+
+static int scst_mgmt_affected_cmds_done(struct scst_mgmt_cmd *mcmd)
+{
+ int res;
+
+ mutex_lock(&scst_mutex);
+
+ switch (mcmd->fn) {
+ case SCST_NEXUS_LOSS_SESS:
+ case SCST_UNREG_SESS_TM:
+ scst_do_nexus_loss_sess(mcmd);
+ break;
+
+ case SCST_NEXUS_LOSS:
+ scst_do_nexus_loss_tgt(mcmd);
+ break;
+ }
+
+ mutex_unlock(&scst_mutex);
+
+ scst_call_task_mgmt_affected_cmds_done(mcmd);
+
+ mcmd->affected_cmds_done_called = 1;
+
+ res = scst_set_mcmd_next_state(mcmd);
+ return res;
+}
+
+static void scst_mgmt_cmd_send_done(struct scst_mgmt_cmd *mcmd)
+{
+ struct scst_device *dev;
+ struct scst_session *sess = mcmd->sess;
+
+ mcmd->state = SCST_MCMD_STATE_FINISHED;
+ if (scst_is_strict_mgmt_fn(mcmd->fn) && (mcmd->completed_cmd_count > 0))
+ mcmd->status = SCST_MGMT_STATUS_TASK_NOT_EXIST;
+
+ TRACE(TRACE_MINOR_AND_MGMT_DBG, "TM command fn %d finished, "
+ "status %x", mcmd->fn, mcmd->status);
+
+ if (!mcmd->affected_cmds_done_called) {
+ /* It might happen in case of errors */
+ scst_call_task_mgmt_affected_cmds_done(mcmd);
+ }
+
+ if ((sess->tgt->tgtt->task_mgmt_fn_done != NULL) &&
+ (mcmd->fn != SCST_UNREG_SESS_TM)) {
+ TRACE_DBG("Calling target %s task_mgmt_fn_done(%p)",
+ sess->tgt->tgtt->name, sess);
+ sess->tgt->tgtt->task_mgmt_fn_done(mcmd);
+ TRACE_MGMT_DBG("Target's %s task_mgmt_fn_done() "
+ "returned", sess->tgt->tgtt->name);
+ }
+
+ if (mcmd->needs_unblocking) {
+ switch (mcmd->fn) {
+ case SCST_LUN_RESET:
+ case SCST_CLEAR_TASK_SET:
+ scst_unblock_dev(mcmd->mcmd_tgt_dev->dev);
+ break;
+
+ case SCST_TARGET_RESET:
+ {
+ struct scst_acg *acg = mcmd->sess->acg;
+ struct scst_acg_dev *acg_dev;
+
+ mutex_lock(&scst_mutex);
+ list_for_each_entry(acg_dev, &acg->acg_dev_list,
+ acg_dev_list_entry) {
+ dev = acg_dev->dev;
+ scst_unblock_dev(dev);
+ }
+ mutex_unlock(&scst_mutex);
+ break;
+ }
+
+ default:
+ BUG();
+ break;
+ }
+ }
+
+ mcmd->tgt_priv = NULL;
+ return;
+}
+
+/* Returns >0, if cmd should be requeued */
+static int scst_process_mgmt_cmd(struct scst_mgmt_cmd *mcmd)
+{
+ int res = 0;
+
+ TRACE_DBG("mcmd %p, state %d", mcmd, mcmd->state);
+
+ while (1) {
+ switch (mcmd->state) {
+ case SCST_MCMD_STATE_INIT:
+ res = scst_mgmt_cmd_init(mcmd);
+ if (res)
+ goto out;
+ break;
+
+ case SCST_MCMD_STATE_READY:
+ if (scst_mgmt_cmd_exec(mcmd))
+ goto out;
+ break;
+
+ case SCST_MCMD_STATE_POST_AFFECTED_CMDS_DONE:
+ if (scst_mgmt_affected_cmds_done(mcmd))
+ goto out;
+ break;
+
+ case SCST_MCMD_STATE_DONE:
+ scst_mgmt_cmd_send_done(mcmd);
+ break;
+
+ default:
+ PRINT_ERROR("Unknown state %d of management command",
+ mcmd->state);
+ res = -1;
+ /* go through */
+ case SCST_MCMD_STATE_FINISHED:
+ scst_free_mgmt_cmd(mcmd);
+ goto out;
+
+#ifdef CONFIG_SCST_EXTRACHECKS
+ case SCST_MCMD_STATE_EXECUTING:
+ BUG();
+#endif
+ }
+ }
+
+out:
+ return res;
+}
+
+static inline int test_mgmt_cmd_list(void)
+{
+ int res = !list_empty(&scst_active_mgmt_cmd_list) ||
+ unlikely(kthread_should_stop());
+ return res;
+}
+
+int scst_tm_thread(void *arg)
+{
+
+ PRINT_INFO("Task management thread started, PID %d", current->pid);
+
+ current->flags |= PF_NOFREEZE;
+
+ set_user_nice(current, -10);
+
+ spin_lock_irq(&scst_mcmd_lock);
+ while (!kthread_should_stop()) {
+ wait_queue_t wait;
+ init_waitqueue_entry(&wait, current);
+
+ if (!test_mgmt_cmd_list()) {
+ add_wait_queue_exclusive(&scst_mgmt_cmd_list_waitQ,
+ &wait);
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (test_mgmt_cmd_list())
+ break;
+ spin_unlock_irq(&scst_mcmd_lock);
+ schedule();
+ spin_lock_irq(&scst_mcmd_lock);
+ }
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&scst_mgmt_cmd_list_waitQ, &wait);
+ }
+
+ while (!list_empty(&scst_active_mgmt_cmd_list)) {
+ int rc;
+ struct scst_mgmt_cmd *mcmd;
+ mcmd = list_entry(scst_active_mgmt_cmd_list.next,
+ typeof(*mcmd), mgmt_cmd_list_entry);
+ TRACE_MGMT_DBG("Deleting mgmt cmd %p from active cmd "
+ "list", mcmd);
+ list_del(&mcmd->mgmt_cmd_list_entry);
+ spin_unlock_irq(&scst_mcmd_lock);
+ rc = scst_process_mgmt_cmd(mcmd);
+ spin_lock_irq(&scst_mcmd_lock);
+ if (rc > 0) {
+ if (test_bit(SCST_FLAG_SUSPENDED, &scst_flags) &&
+ !test_bit(SCST_FLAG_SUSPENDING,
+ &scst_flags)) {
+ TRACE_MGMT_DBG("Adding mgmt cmd %p to "
+ "head of delayed mgmt cmd list",
+ mcmd);
+ list_add(&mcmd->mgmt_cmd_list_entry,
+ &scst_delayed_mgmt_cmd_list);
+ } else {
+ TRACE_MGMT_DBG("Adding mgmt cmd %p to "
+ "head of active mgmt cmd list",
+ mcmd);
+ list_add(&mcmd->mgmt_cmd_list_entry,
+ &scst_active_mgmt_cmd_list);
+ }
+ }
+ }
+ }
+ spin_unlock_irq(&scst_mcmd_lock);
+
+ /*
+ * If kthread_should_stop() is true, we are guaranteed to be
+ * on the module unload, so scst_active_mgmt_cmd_list must be empty.
+ */
+ BUG_ON(!list_empty(&scst_active_mgmt_cmd_list));
+
+ PRINT_INFO("Task management thread PID %d finished", current->pid);
+ return 0;
+}
+
+static struct scst_mgmt_cmd *scst_pre_rx_mgmt_cmd(struct scst_session
+ *sess, int fn, int atomic, void *tgt_priv)
+{
+ struct scst_mgmt_cmd *mcmd = NULL;
+
+ if (unlikely(sess->tgt->tgtt->task_mgmt_fn_done == NULL)) {
+ PRINT_ERROR("New mgmt cmd, but task_mgmt_fn_done() is NULL "
+ "(target %s)", sess->tgt->tgtt->name);
+ goto out;
+ }
+
+ mcmd = scst_alloc_mgmt_cmd(atomic ? GFP_ATOMIC : GFP_KERNEL);
+ if (mcmd == NULL) {
+ PRINT_CRIT_ERROR("Lost TM fn %d, initiator %s", fn,
+ sess->initiator_name);
+ goto out;
+ }
+
+ mcmd->sess = sess;
+ mcmd->fn = fn;
+ mcmd->state = SCST_MCMD_STATE_INIT;
+ mcmd->tgt_priv = tgt_priv;
+
+out:
+ return mcmd;
+}
+
+static int scst_post_rx_mgmt_cmd(struct scst_session *sess,
+ struct scst_mgmt_cmd *mcmd)
+{
+ unsigned long flags;
+ int res = 0;
+
+ scst_sess_get(sess);
+
+ if (unlikely(sess->shut_phase != SCST_SESS_SPH_READY)) {
+ PRINT_CRIT_ERROR("New mgmt cmd while shutting down the "
+ "session %p shut_phase %ld", sess, sess->shut_phase);
+ BUG();
+ }
+
+ local_irq_save(flags);
+
+ spin_lock(&sess->sess_list_lock);
+ atomic_inc(&sess->sess_cmd_count);
+
+ if (unlikely(sess->init_phase != SCST_SESS_IPH_READY)) {
+ switch (sess->init_phase) {
+ case SCST_SESS_IPH_INITING:
+ TRACE_DBG("Adding mcmd %p to init deferred mcmd list",
+ mcmd);
+ list_add_tail(&mcmd->mgmt_cmd_list_entry,
+ &sess->init_deferred_mcmd_list);
+ goto out_unlock;
+ case SCST_SESS_IPH_SUCCESS:
+ break;
+ case SCST_SESS_IPH_FAILED:
+ res = -1;
+ goto out_unlock;
+ default:
+ BUG();
+ }
+ }
+
+ spin_unlock(&sess->sess_list_lock);
+
+ TRACE_MGMT_DBG("Adding mgmt cmd %p to active mgmt cmd list", mcmd);
+ spin_lock(&scst_mcmd_lock);
+ list_add_tail(&mcmd->mgmt_cmd_list_entry, &scst_active_mgmt_cmd_list);
+ spin_unlock(&scst_mcmd_lock);
+
+ local_irq_restore(flags);
+
+ wake_up(&scst_mgmt_cmd_list_waitQ);
+
+out:
+ return res;
+
+out_unlock:
+ spin_unlock(&sess->sess_list_lock);
+ local_irq_restore(flags);
+ goto out;
+}
+
+/**
+ * scst_rx_mgmt_fn() - create new management command and send it for execution
+ *
+ * Description:
+ * Creates new management command and sends it for execution.
+ *
+ * Returns 0 for success, error code otherwise.
+ *
+ * Must not be called in parallel with scst_unregister_session() for the
+ * same sess.
+ */
+int scst_rx_mgmt_fn(struct scst_session *sess,
+ const struct scst_rx_mgmt_params *params)
+{
+ int res = -EFAULT;
+ struct scst_mgmt_cmd *mcmd = NULL;
+
+ switch (params->fn) {
+ case SCST_ABORT_TASK:
+ BUG_ON(!params->tag_set);
+ break;
+ case SCST_TARGET_RESET:
+ case SCST_ABORT_ALL_TASKS:
+ case SCST_NEXUS_LOSS:
+ break;
+ default:
+ BUG_ON(!params->lun_set);
+ }
+
+ mcmd = scst_pre_rx_mgmt_cmd(sess, params->fn, params->atomic,
+ params->tgt_priv);
+ if (mcmd == NULL)
+ goto out;
+
+ if (params->lun_set) {
+ mcmd->lun = scst_unpack_lun(params->lun, params->lun_len);
+ if (mcmd->lun == NO_SUCH_LUN)
+ goto out_free;
+ mcmd->lun_set = 1;
+ }
+
+ if (params->tag_set)
+ mcmd->tag = params->tag;
+
+ mcmd->cmd_sn_set = params->cmd_sn_set;
+ mcmd->cmd_sn = params->cmd_sn;
+
+ TRACE(TRACE_MGMT, "TM fn %d", params->fn);
+
+ TRACE_MGMT_DBG("sess=%p, tag_set %d, tag %lld, lun_set %d, "
+ "lun=%lld, cmd_sn_set %d, cmd_sn %d, priv %p", sess,
+ params->tag_set,
+ (long long unsigned int)params->tag,
+ params->lun_set,
+ (long long unsigned int)mcmd->lun,
+ params->cmd_sn_set,
+ params->cmd_sn,
+ params->tgt_priv);
+
+ if (scst_post_rx_mgmt_cmd(sess, mcmd) != 0)
+ goto out_free;
+
+ res = 0;
+
+out:
+ return res;
+
+out_free:
+ scst_free_mgmt_cmd(mcmd);
+ mcmd = NULL;
+ goto out;
+}
+EXPORT_SYMBOL(scst_rx_mgmt_fn);
+
+/*
+ * Returns true if string "string" matches pattern "wild", false otherwise.
+ * Pattern is a regular DOS-type pattern, containing '*' and '?' symbols.
+ * '*' means match all any symbols, '?' means match only any single symbol.
+ *
+ * For instance:
+ * if (wildcmp("bl?h.*", "blah.jpg")) {
+ * // match
+ * } else {
+ * // no match
+ * }
+ *
+ * Written by Jack Handy - jakkhandy@...mail.com
+ * Taken by Gennadiy Nerubayev <parakie@...il.com> from
+ * http://www.codeproject.com/KB/string/wildcmp.aspx. No license attached
+ * to it, and it's posted on a free site; assumed to be free for use.
+ */
+static bool wildcmp(const char *wild, const char *string)
+{
+ const char *cp = NULL, *mp = NULL;
+
+ while ((*string) && (*wild != '*')) {
+ if ((*wild != *string) && (*wild != '?'))
+ return false;
+
+ wild++;
+ string++;
+ }
+
+ while (*string) {
+ if (*wild == '*') {
+ if (!*++wild)
+ return true;
+
+ mp = wild;
+ cp = string+1;
+ } else if ((*wild == *string) || (*wild == '?')) {
+ wild++;
+ string++;
+ } else {
+ wild = mp;
+ string = cp++;
+ }
+ }
+
+ while (*wild == '*')
+ wild++;
+
+ return !*wild;
+}
+
+/* scst_mutex supposed to be held */
+static struct scst_acg *scst_find_tgt_acg_by_name_wild(struct scst_tgt *tgt,
+ const char *initiator_name)
+{
+ struct scst_acg *acg, *res = NULL;
+ struct scst_acn *n;
+
+ if (initiator_name == NULL)
+ goto out;
+
+ list_for_each_entry(acg, &tgt->tgt_acg_list, acg_list_entry) {
+ list_for_each_entry(n, &acg->acn_list, acn_list_entry) {
+ if (wildcmp(n->name, initiator_name)) {
+ TRACE_DBG("Access control group %s found",
+ acg->acg_name);
+ res = acg;
+ goto out;
+ }
+ }
+ }
+
+out:
+ return res;
+}
+
+/* Must be called under scst_mutex */
+struct scst_acg *scst_find_acg(const struct scst_session *sess)
+{
+ struct scst_acg *acg = NULL;
+
+ acg = scst_find_tgt_acg_by_name_wild(sess->tgt, sess->initiator_name);
+ if (acg == NULL)
+ acg = sess->tgt->default_acg;
+ return acg;
+}
+
+static int scst_init_session(struct scst_session *sess)
+{
+ int res = 0, rc;
+ struct scst_cmd *cmd;
+ struct scst_mgmt_cmd *mcmd, *tm;
+ int mwake = 0;
+
+ mutex_lock(&scst_mutex);
+
+ sess->acg = scst_find_acg(sess);
+
+ PRINT_INFO("Using security group \"%s\" for initiator \"%s\"",
+ sess->acg->acg_name, sess->initiator_name);
+
+ list_add_tail(&sess->acg_sess_list_entry, &sess->acg->acg_sess_list);
+
+ TRACE_DBG("Adding sess %p to tgt->sess_list", sess);
+ list_add_tail(&sess->sess_list_entry, &sess->tgt->sess_list);
+
+ res = scst_sess_alloc_tgt_devs(sess);
+
+ /* Let's always create session's sysfs to simplify error recovery */
+ rc = scst_create_sess_sysfs(sess);
+ if (res == 0)
+ res = rc;
+
+ mutex_unlock(&scst_mutex);
+
+ if (sess->init_result_fn) {
+ TRACE_DBG("Calling init_result_fn(%p)", sess);
+ sess->init_result_fn(sess, sess->reg_sess_data, res);
+ TRACE_DBG("%s", "init_result_fn() returned");
+ }
+
+ spin_lock_irq(&sess->sess_list_lock);
+
+ if (res == 0)
+ sess->init_phase = SCST_SESS_IPH_SUCCESS;
+ else
+ sess->init_phase = SCST_SESS_IPH_FAILED;
+
+restart:
+ list_for_each_entry(cmd, &sess->init_deferred_cmd_list,
+ cmd_list_entry) {
+ TRACE_DBG("Deleting cmd %p from init deferred cmd list", cmd);
+ list_del(&cmd->cmd_list_entry);
+ atomic_dec(&sess->sess_cmd_count);
+ spin_unlock_irq(&sess->sess_list_lock);
+ scst_cmd_init_done(cmd, SCST_CONTEXT_THREAD);
+ spin_lock_irq(&sess->sess_list_lock);
+ goto restart;
+ }
+
+ spin_lock(&scst_mcmd_lock);
+ list_for_each_entry_safe(mcmd, tm, &sess->init_deferred_mcmd_list,
+ mgmt_cmd_list_entry) {
+ TRACE_DBG("Moving mgmt command %p from init deferred mcmd list",
+ mcmd);
+ list_move_tail(&mcmd->mgmt_cmd_list_entry,
+ &scst_active_mgmt_cmd_list);
+ mwake = 1;
+ }
+
+ spin_unlock(&scst_mcmd_lock);
+ /*
+ * In case of an error at this point the caller target driver supposed
+ * to already call this sess's unregistration.
+ */
+ sess->init_phase = SCST_SESS_IPH_READY;
+ spin_unlock_irq(&sess->sess_list_lock);
+
+ if (mwake)
+ wake_up(&scst_mgmt_cmd_list_waitQ);
+
+ scst_sess_put(sess);
+ return res;
+}
+
+/**
+ * scst_register_session() - register session
+ * @tgt: target
+ * @atomic: true, if the function called in the atomic context. If false,
+ * this function will block until the session registration is
+ * completed.
+ * @initiator_name: remote initiator's name, any NULL-terminated string,
+ * e.g. iSCSI name, which used as the key to found appropriate
+ * access control group. Could be NULL, then the default
+ * target's LUNs are used.
+ * @data: any target driver supplied data
+ * @result_fn: pointer to the function that will be asynchronously called
+ * when session initialization finishes.
+ * Can be NULL. Parameters:
+ * - sess - session
+ * - data - target driver supplied to scst_register_session()
+ * data
+ * - result - session initialization result, 0 on success or
+ * appropriate error code otherwise
+ *
+ * Description:
+ * Registers new session. Returns new session on success or NULL otherwise.
+ *
+ * Note: A session creation and initialization is a complex task,
+ * which requires sleeping state, so it can't be fully done
+ * in interrupt context. Therefore the "bottom half" of it, if
+ * scst_register_session() is called from atomic context, will be
+ * done in SCST thread context. In this case scst_register_session()
+ * will return not completely initialized session, but the target
+ * driver can supply commands to this session via scst_rx_cmd().
+ * Those commands processing will be delayed inside SCST until
+ * the session initialization is finished, then their processing
+ * will be restarted. The target driver will be notified about
+ * finish of the session initialization by function result_fn().
+ * On success the target driver could do nothing, but if the
+ * initialization fails, the target driver must ensure that
+ * no more new commands being sent or will be sent to SCST after
+ * result_fn() returns. All already sent to SCST commands for
+ * failed session will be returned in xmit_response() with BUSY status.
+ * In case of failure the driver shall call scst_unregister_session()
+ * inside result_fn(), it will NOT be called automatically.
+ */
+struct scst_session *scst_register_session(struct scst_tgt *tgt, int atomic,
+ const char *initiator_name, void *data,
+ void (*result_fn) (struct scst_session *sess, void *data, int result))
+{
+ struct scst_session *sess;
+ int res;
+ unsigned long flags;
+
+ sess = scst_alloc_session(tgt, atomic ? GFP_ATOMIC : GFP_KERNEL,
+ initiator_name);
+ if (sess == NULL)
+ goto out;
+
+ scst_sess_get(sess); /* one for registered session */
+ scst_sess_get(sess); /* one held until sess is inited */
+
+ if (atomic) {
+ sess->reg_sess_data = data;
+ sess->init_result_fn = result_fn;
+ spin_lock_irqsave(&scst_mgmt_lock, flags);
+ TRACE_DBG("Adding sess %p to scst_sess_init_list", sess);
+ list_add_tail(&sess->sess_init_list_entry,
+ &scst_sess_init_list);
+ spin_unlock_irqrestore(&scst_mgmt_lock, flags);
+ wake_up(&scst_mgmt_waitQ);
+ } else {
+ res = scst_init_session(sess);
+ if (res != 0)
+ goto out_free;
+ }
+
+out:
+ return sess;
+
+out_free:
+ scst_free_session(sess);
+ sess = NULL;
+ goto out;
+}
+EXPORT_SYMBOL_GPL(scst_register_session);
+
+/**
+ * scst_register_session_simple() - register session (simple version)
+ * @tgt: target
+ * @initiator_name: remote initiator's name, any NULL-terminated string,
+ * e.g. iSCSI name, which used as the key to found appropriate
+ * access control group. Could be NULL, then the default
+ * target's LUNs are used.
+ *
+ * Description:
+ * Registers new session. Returns new session on success or NULL otherwise.
+ */
+struct scst_session *scst_register_session_simple(struct scst_tgt *tgt,
+ const char *initiator_name)
+{
+ return scst_register_session(tgt, 0, initiator_name, NULL, NULL);
+}
+EXPORT_SYMBOL(scst_register_session_simple);
+
+/**
+ * scst_unregister_session() - unregister session
+ * @sess: session to be unregistered
+ * @wait: if true, instructs to wait until all commands, which
+ * currently is being executed and belonged to the session,
+ * finished. Otherwise, target driver should be prepared to
+ * receive xmit_response() for the session's command after
+ * scst_unregister_session() returns.
+ * @unreg_done_fn: pointer to the function that will be asynchronously called
+ * when the last session's command finishes and
+ * the session is about to be completely freed. Can be NULL.
+ * Parameter:
+ * - sess - session
+ *
+ * Unregisters session.
+ *
+ * Notes:
+ * - All outstanding commands will be finished regularly. After
+ * scst_unregister_session() returned, no new commands must be sent to
+ * SCST via scst_rx_cmd().
+ *
+ * - The caller must ensure that no scst_rx_cmd() or scst_rx_mgmt_fn_*() is
+ * called in paralell with scst_unregister_session().
+ *
+ * - Can be called before result_fn() of scst_register_session() called,
+ * i.e. during the session registration/initialization.
+ *
+ * - It is highly recommended to call scst_unregister_session() as soon as it
+ * gets clear that session will be unregistered and not to wait until all
+ * related commands finished. This function provides the wait functionality,
+ * but it also starts recovering stuck commands, if there are any.
+ * Otherwise, your target driver could wait for those commands forever.
+ */
+void scst_unregister_session(struct scst_session *sess, int wait,
+ void (*unreg_done_fn) (struct scst_session *sess))
+{
+ unsigned long flags;
+ DECLARE_COMPLETION_ONSTACK(c);
+ int rc, lun;
+
+ TRACE_MGMT_DBG("Unregistering session %p (wait %d)", sess, wait);
+
+ sess->unreg_done_fn = unreg_done_fn;
+
+ /* Abort all outstanding commands and clear reservation, if necessary */
+ lun = 0;
+ rc = scst_rx_mgmt_fn_lun(sess, SCST_UNREG_SESS_TM,
+ (uint8_t *)&lun, sizeof(lun), SCST_ATOMIC, NULL);
+ if (rc != 0) {
+ PRINT_ERROR("SCST_UNREG_SESS_TM failed %d (sess %p)",
+ rc, sess);
+ }
+
+ sess->shut_phase = SCST_SESS_SPH_SHUTDOWN;
+
+ spin_lock_irqsave(&scst_mgmt_lock, flags);
+
+ if (wait)
+ sess->shutdown_compl = &c;
+
+ spin_unlock_irqrestore(&scst_mgmt_lock, flags);
+
+ scst_sess_put(sess);
+
+ if (wait) {
+ TRACE_DBG("Waiting for session %p to complete", sess);
+ wait_for_completion(&c);
+ }
+ return;
+}
+EXPORT_SYMBOL_GPL(scst_unregister_session);
+
+/**
+ * scst_unregister_session_simple() - unregister session, simple version
+ * @sess: session to be unregistered
+ *
+ * Unregisters session.
+ *
+ * See notes for scst_unregister_session() above.
+ */
+void scst_unregister_session_simple(struct scst_session *sess)
+{
+
+ scst_unregister_session(sess, 1, NULL);
+ return;
+}
+EXPORT_SYMBOL(scst_unregister_session_simple);
+
+static inline int test_mgmt_list(void)
+{
+ int res = !list_empty(&scst_sess_init_list) ||
+ !list_empty(&scst_sess_shut_list) ||
+ unlikely(kthread_should_stop());
+ return res;
+}
+
+int scst_global_mgmt_thread(void *arg)
+{
+ struct scst_session *sess;
+
+ PRINT_INFO("Management thread started, PID %d", current->pid);
+
+ current->flags |= PF_NOFREEZE;
+
+ set_user_nice(current, -10);
+
+ spin_lock_irq(&scst_mgmt_lock);
+ while (!kthread_should_stop()) {
+ wait_queue_t wait;
+ init_waitqueue_entry(&wait, current);
+
+ if (!test_mgmt_list()) {
+ add_wait_queue_exclusive(&scst_mgmt_waitQ, &wait);
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (test_mgmt_list())
+ break;
+ spin_unlock_irq(&scst_mgmt_lock);
+ schedule();
+ spin_lock_irq(&scst_mgmt_lock);
+ }
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&scst_mgmt_waitQ, &wait);
+ }
+
+ while (!list_empty(&scst_sess_init_list)) {
+ sess = list_entry(scst_sess_init_list.next,
+ typeof(*sess), sess_init_list_entry);
+ TRACE_DBG("Removing sess %p from scst_sess_init_list",
+ sess);
+ list_del(&sess->sess_init_list_entry);
+ spin_unlock_irq(&scst_mgmt_lock);
+
+ if (sess->init_phase == SCST_SESS_IPH_INITING)
+ scst_init_session(sess);
+ else {
+ PRINT_CRIT_ERROR("session %p is in "
+ "scst_sess_init_list, but in unknown "
+ "init phase %x", sess,
+ sess->init_phase);
+ BUG();
+ }
+
+ spin_lock_irq(&scst_mgmt_lock);
+ }
+
+ while (!list_empty(&scst_sess_shut_list)) {
+ sess = list_entry(scst_sess_shut_list.next,
+ typeof(*sess), sess_shut_list_entry);
+ TRACE_DBG("Removing sess %p from scst_sess_shut_list",
+ sess);
+ list_del(&sess->sess_shut_list_entry);
+ spin_unlock_irq(&scst_mgmt_lock);
+
+ switch (sess->shut_phase) {
+ case SCST_SESS_SPH_SHUTDOWN:
+ BUG_ON(atomic_read(&sess->refcnt) != 0);
+ scst_free_session_callback(sess);
+ break;
+ default:
+ PRINT_CRIT_ERROR("session %p is in "
+ "scst_sess_shut_list, but in unknown "
+ "shut phase %lx", sess,
+ sess->shut_phase);
+ BUG();
+ break;
+ }
+
+ spin_lock_irq(&scst_mgmt_lock);
+ }
+ }
+ spin_unlock_irq(&scst_mgmt_lock);
+
+ /*
+ * If kthread_should_stop() is true, we are guaranteed to be
+ * on the module unload, so both lists must be empty.
+ */
+ BUG_ON(!list_empty(&scst_sess_init_list));
+ BUG_ON(!list_empty(&scst_sess_shut_list));
+
+ PRINT_INFO("Management thread PID %d finished", current->pid);
+ return 0;
+}
+
+/* Called under sess->sess_list_lock */
+static struct scst_cmd *__scst_find_cmd_by_tag(struct scst_session *sess,
+ uint64_t tag, bool to_abort)
+{
+ struct scst_cmd *cmd, *res = NULL;
+
+ /* ToDo: hash list */
+
+ TRACE_DBG("%s (sess=%p, tag=%llu)", "Searching in sess cmd list",
+ sess, (long long unsigned int)tag);
+
+ list_for_each_entry(cmd, &sess->sess_cmd_list,
+ sess_cmd_list_entry) {
+ if (cmd->tag == tag) {
+ /*
+ * We must not count done commands, because
+ * they were submitted for transmittion.
+ * Otherwise we can have a race, when for
+ * some reason cmd's release delayed
+ * after transmittion and initiator sends
+ * cmd with the same tag => it can be possible
+ * that a wrong cmd will be returned.
+ */
+ if (cmd->done) {
+ if (to_abort) {
+ /*
+ * We should return the latest not
+ * aborted cmd with this tag.
+ */
+ if (res == NULL)
+ res = cmd;
+ else {
+ if (test_bit(SCST_CMD_ABORTED,
+ &res->cmd_flags)) {
+ res = cmd;
+ } else if (!test_bit(SCST_CMD_ABORTED,
+ &cmd->cmd_flags))
+ res = cmd;
+ }
+ }
+ continue;
+ } else {
+ res = cmd;
+ break;
+ }
+ }
+ }
+ return res;
+}
+
+/**
+ * scst_find_cmd() - find command by custom comparison function
+ *
+ * Finds a command based on user supplied data and comparision
+ * callback function, that should return true, if the command is found.
+ * Returns the command on success or NULL otherwise
+ */
+struct scst_cmd *scst_find_cmd(struct scst_session *sess, void *data,
+ int (*cmp_fn) (struct scst_cmd *cmd,
+ void *data))
+{
+ struct scst_cmd *cmd = NULL;
+ unsigned long flags = 0;
+
+ if (cmp_fn == NULL)
+ goto out;
+
+ spin_lock_irqsave(&sess->sess_list_lock, flags);
+
+ TRACE_DBG("Searching in sess cmd list (sess=%p)", sess);
+ list_for_each_entry(cmd, &sess->sess_cmd_list, sess_cmd_list_entry) {
+ /*
+ * We must not count done commands, because they were
+ * submitted for transmittion. Otherwise we can have a race,
+ * when for some reason cmd's release delayed after
+ * transmittion and initiator sends cmd with the same tag =>
+ * it can be possible that a wrong cmd will be returned.
+ */
+ if (cmd->done)
+ continue;
+ if (cmp_fn(cmd, data))
+ goto out_unlock;
+ }
+
+ cmd = NULL;
+
+out_unlock:
+ spin_unlock_irqrestore(&sess->sess_list_lock, flags);
+
+out:
+ return cmd;
+}
+EXPORT_SYMBOL(scst_find_cmd);
+
+/**
+ * scst_find_cmd_by_tag() - find command by tag
+ *
+ * Finds a command based on the supplied tag comparing it with one
+ * that previously set by scst_cmd_set_tag(). Returns the found command on
+ * success or NULL otherwise
+ */
+struct scst_cmd *scst_find_cmd_by_tag(struct scst_session *sess,
+ uint64_t tag)
+{
+ unsigned long flags;
+ struct scst_cmd *cmd;
+ spin_lock_irqsave(&sess->sess_list_lock, flags);
+ cmd = __scst_find_cmd_by_tag(sess, tag, false);
+ spin_unlock_irqrestore(&sess->sess_list_lock, flags);
+ return cmd;
+}
+EXPORT_SYMBOL(scst_find_cmd_by_tag);
--
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