// SPDX-License-Identifier: GPL-2.0-or-later /* * Generic SCSI-3 ALUA SCSI Device Handler * * Copyright (C) 2007-2010 Hannes Reinecke, SUSE Linux Products GmbH. * All rights reserved. */ #include <linux/slab.h> #include <linux/delay.h> #include <linux/module.h> #include <linux/unaligned.h> #include <scsi/scsi.h> #include <scsi/scsi_proto.h> #include <scsi/scsi_dbg.h> #include <scsi/scsi_eh.h> #include <scsi/scsi_dh.h> #define ALUA_DH_NAME … #define ALUA_DH_VER … #define TPGS_SUPPORT_NONE … #define TPGS_SUPPORT_OPTIMIZED … #define TPGS_SUPPORT_NONOPTIMIZED … #define TPGS_SUPPORT_STANDBY … #define TPGS_SUPPORT_UNAVAILABLE … #define TPGS_SUPPORT_LBA_DEPENDENT … #define TPGS_SUPPORT_OFFLINE … #define TPGS_SUPPORT_TRANSITION … #define TPGS_SUPPORT_ALL … #define RTPG_FMT_MASK … #define RTPG_FMT_EXT_HDR … #define TPGS_MODE_UNINITIALIZED … #define TPGS_MODE_NONE … #define TPGS_MODE_IMPLICIT … #define TPGS_MODE_EXPLICIT … #define ALUA_RTPG_SIZE … #define ALUA_FAILOVER_TIMEOUT … #define ALUA_FAILOVER_RETRIES … #define ALUA_RTPG_DELAY_MSECS … #define ALUA_RTPG_RETRY_DELAY … /* device handler flags */ #define ALUA_OPTIMIZE_STPG … #define ALUA_RTPG_EXT_HDR_UNSUPP … /* State machine flags */ #define ALUA_PG_RUN_RTPG … #define ALUA_PG_RUN_STPG … #define ALUA_PG_RUNNING … static uint optimize_stpg; module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR); MODULE_PARM_DESC(…) …; static LIST_HEAD(port_group_list); static DEFINE_SPINLOCK(port_group_lock); static struct workqueue_struct *kaluad_wq; struct alua_port_group { … }; struct alua_dh_data { … }; struct alua_queue_data { … }; #define ALUA_POLICY_SWITCH_CURRENT … #define ALUA_POLICY_SWITCH_ALL … static void alua_rtpg_work(struct work_struct *work); static bool alua_rtpg_queue(struct alua_port_group *pg, struct scsi_device *sdev, struct alua_queue_data *qdata, bool force); static void alua_check(struct scsi_device *sdev, bool force); static void release_port_group(struct kref *kref) { … } /* * submit_rtpg - Issue a REPORT TARGET GROUP STATES command * @sdev: sdev the command should be sent to */ static int submit_rtpg(struct scsi_device *sdev, unsigned char *buff, int bufflen, struct scsi_sense_hdr *sshdr, int flags) { … } /* * submit_stpg - Issue a SET TARGET PORT GROUP command * * Currently we're only setting the current target port group state * to 'active/optimized' and let the array firmware figure out * the states of the remaining groups. */ static int submit_stpg(struct scsi_device *sdev, int group_id, struct scsi_sense_hdr *sshdr) { … } static struct alua_port_group *alua_find_get_pg(char *id_str, size_t id_size, int group_id) { … } /* * alua_alloc_pg - Allocate a new port_group structure * @sdev: scsi device * @group_id: port group id * @tpgs: target port group settings * * Allocate a new port_group structure for a given * device. */ static struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev, int group_id, int tpgs) { … } /* * alua_check_tpgs - Evaluate TPGS setting * @sdev: device to be checked * * Examine the TPGS setting of the sdev to find out if ALUA * is supported. */ static int alua_check_tpgs(struct scsi_device *sdev) { … } /* * alua_check_vpd - Evaluate INQUIRY vpd page 0x83 * @sdev: device to be checked * * Extract the relative target port and the target port group * descriptor from the list of identificators. */ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h, int tpgs) { … } static char print_alua_state(unsigned char state) { … } static void alua_handle_state_transition(struct scsi_device *sdev) { … } static enum scsi_disposition alua_check_sense(struct scsi_device *sdev, struct scsi_sense_hdr *sense_hdr) { … } /* * alua_tur - Send a TEST UNIT READY * @sdev: device to which the TEST UNIT READY command should be send * * Send a TEST UNIT READY to @sdev to figure out the device state * Returns SCSI_DH_RETRY if the sense code is NOT READY/ALUA TRANSITIONING, * SCSI_DH_OK if no error occurred, and SCSI_DH_IO otherwise. */ static int alua_tur(struct scsi_device *sdev) { … } /* * alua_rtpg - Evaluate REPORT TARGET GROUP STATES * @sdev: the device to be evaluated. * * Evaluate the Target Port Group State. * Returns SCSI_DH_DEV_OFFLINED if the path is * found to be unusable. */ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) { … } /* * alua_stpg - Issue a SET TARGET PORT GROUP command * * Issue a SET TARGET PORT GROUP command and evaluate the * response. Returns SCSI_DH_RETRY per default to trigger * a re-evaluation of the target group state or SCSI_DH_OK * if no further action needs to be taken. */ static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg) { … } /* * The caller must call scsi_device_put() on the returned pointer if it is not * NULL. */ static struct scsi_device * __must_check alua_rtpg_select_sdev(struct alua_port_group *pg) { … } static void alua_rtpg_work(struct work_struct *work) { … } /** * alua_rtpg_queue() - cause RTPG to be submitted asynchronously * @pg: ALUA port group associated with @sdev. * @sdev: SCSI device for which to submit an RTPG. * @qdata: Information about the callback to invoke after the RTPG. * @force: Whether or not to submit an RTPG if a work item that will submit an * RTPG already has been scheduled. * * Returns true if and only if alua_rtpg_work() will be called asynchronously. * That function is responsible for calling @qdata->fn(). * * Context: may be called from atomic context (alua_check()) only if the caller * holds an sdev reference. */ static bool alua_rtpg_queue(struct alua_port_group *pg, struct scsi_device *sdev, struct alua_queue_data *qdata, bool force) { … } /* * alua_initialize - Initialize ALUA state * @sdev: the device to be initialized * * For the prep_fn to work correctly we have * to initialize the ALUA state for the device. */ static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) { … } /* * alua_set_params - set/unset the optimize flag * @sdev: device on the path to be activated * params - parameters in the following format * "no_of_params\0param1\0param2\0param3\0...\0" * For example, to set the flag pass the following parameters * from multipath.conf * hardware_handler "2 alua 1" */ static int alua_set_params(struct scsi_device *sdev, const char *params) { … } /* * alua_activate - activate a path * @sdev: device on the path to be activated * * We're currently switching the port group to be activated only and * let the array figure out the rest. * There may be other arrays which require us to switch all port groups * based on a certain policy. But until we actually encounter them it * should be okay. */ static int alua_activate(struct scsi_device *sdev, activate_complete fn, void *data) { … } /* * alua_check - check path status * @sdev: device on the path to be checked * * Check the device status */ static void alua_check(struct scsi_device *sdev, bool force) { … } /* * alua_prep_fn - request callback * * Fail I/O to all paths not in state * active/optimized or active/non-optimized. */ static blk_status_t alua_prep_fn(struct scsi_device *sdev, struct request *req) { … } static void alua_rescan(struct scsi_device *sdev) { … } /* * alua_bus_attach - Attach device handler * @sdev: device to be attached to */ static int alua_bus_attach(struct scsi_device *sdev) { … } /* * alua_bus_detach - Detach device handler * @sdev: device to be detached from */ static void alua_bus_detach(struct scsi_device *sdev) { … } static struct scsi_device_handler alua_dh = …; static int __init alua_init(void) { … } static void __exit alua_exit(void) { … } module_init(…) …; module_exit(alua_exit); MODULE_DESCRIPTION(…) …; MODULE_AUTHOR(…) …; MODULE_LICENSE(…) …; MODULE_VERSION(…);
Codebase Browser
linux