linux_dsm_epyc7002/drivers/s390/scsi/zfcp_ext.h
Steffen Maier ef4021fe5f scsi: zfcp: fix to prevent port_remove with pure auto scan LUNs (only sdevs)
When the user tries to remove a zfcp port via sysfs, we only rejected it if
there are zfcp unit children under the port. With purely automatically
scanned LUNs there are no zfcp units but only SCSI devices. In such cases,
the port_remove erroneously continued. We close the port and this
implicitly closes all LUNs under the port. The SCSI devices survive with
their private zfcp_scsi_dev still holding a reference to the "removed"
zfcp_port (still allocated but invisible in sysfs) [zfcp_get_port_by_wwpn
in zfcp_scsi_slave_alloc]. This is not a problem as long as the fc_rport
stays blocked. Once (auto) port scan brings back the removed port, we
unblock its fc_rport again by design.  However, there is no mechanism that
would recover (open) the LUNs under the port (no "ersfs_3" without
zfcp_unit [zfcp_erp_strategy_followup_success]).  Any pending or new I/O to
such LUN leads to repeated:

  Done: NEEDS_RETRY Result: hostbyte=DID_IMM_RETRY driverbyte=DRIVER_OK

See also v4.10 commit 6f2ce1c6af ("scsi: zfcp: fix rport unblock race
with LUN recovery"). Even a manual LUN recovery
(echo 0 > /sys/bus/scsi/devices/H:C:T:L/zfcp_failed)
does not help, as the LUN links to the old "removed" port which remains
to lack ZFCP_STATUS_COMMON_RUNNING [zfcp_erp_required_act].
The only workaround is to first ensure that the fc_rport is blocked
(e.g. port_remove again in case it was re-discovered by (auto) port scan),
then delete the SCSI devices, and finally re-discover by (auto) port scan.
The port scan includes an fc_rport unblock, which in turn triggers
a new scan on the scsi target to freshly get new pure auto scan LUNs.

Fix this by rejecting port_remove also if there are SCSI devices
(even without any zfcp_unit) under this port. Re-use mechanics from v3.7
commit d99b601b63 ("[SCSI] zfcp: restore refcount check on port_remove").
However, we have to give up zfcp_sysfs_port_units_mutex earlier in unit_add
to prevent a deadlock with scsi_host scan taking shost->scan_mutex first
and then zfcp_sysfs_port_units_mutex now in our zfcp_scsi_slave_alloc().

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: b62a8d9b45 ("[SCSI] zfcp: Use SCSI device data zfcp scsi dev instead of zfcp unit")
Fixes: f8210e3488 ("[SCSI] zfcp: Allow midlayer to scan for LUNs when running in NPIV mode")
Cc: <stable@vger.kernel.org> #2.6.37+
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-05-29 21:52:31 -04:00

182 lines
8.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* zfcp device driver
*
* External function declarations.
*
* Copyright IBM Corp. 2002, 2018
*/
#ifndef ZFCP_EXT_H
#define ZFCP_EXT_H
#include <linux/types.h>
#include <scsi/fc/fc_els.h>
#include "zfcp_def.h"
#include "zfcp_fc.h"
/* zfcp_aux.c */
extern struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *, u64);
extern struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *);
extern struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *, u64, u32,
u32);
extern void zfcp_sg_free_table(struct scatterlist *, int);
extern int zfcp_sg_setup_table(struct scatterlist *, int);
extern void zfcp_adapter_release(struct kref *);
extern void zfcp_adapter_unregister(struct zfcp_adapter *);
/* zfcp_ccw.c */
extern struct ccw_driver zfcp_ccw_driver;
extern struct zfcp_adapter *zfcp_ccw_adapter_by_cdev(struct ccw_device *);
extern void zfcp_ccw_adapter_put(struct zfcp_adapter *);
/* zfcp_dbf.c */
extern int zfcp_dbf_adapter_register(struct zfcp_adapter *);
extern void zfcp_dbf_adapter_unregister(struct zfcp_adapter *);
extern void zfcp_dbf_rec_trig(char *, struct zfcp_adapter *,
struct zfcp_port *, struct scsi_device *, u8, u8);
extern void zfcp_dbf_rec_trig_lock(char *tag, struct zfcp_adapter *adapter,
struct zfcp_port *port,
struct scsi_device *sdev, u8 want, u8 need);
extern void zfcp_dbf_rec_run(char *, struct zfcp_erp_action *);
extern void zfcp_dbf_rec_run_lvl(int level, char *tag,
struct zfcp_erp_action *erp);
extern void zfcp_dbf_rec_run_wka(char *, struct zfcp_fc_wka_port *, u64);
extern void zfcp_dbf_hba_fsf_uss(char *, struct zfcp_fsf_req *);
extern void zfcp_dbf_hba_fsf_res(char *, int, struct zfcp_fsf_req *);
extern void zfcp_dbf_hba_bit_err(char *, struct zfcp_fsf_req *);
extern void zfcp_dbf_hba_def_err(struct zfcp_adapter *, u64, u16, void **);
extern void zfcp_dbf_hba_basic(char *, struct zfcp_adapter *);
extern void zfcp_dbf_san_req(char *, struct zfcp_fsf_req *, u32);
extern void zfcp_dbf_san_res(char *, struct zfcp_fsf_req *);
extern void zfcp_dbf_san_in_els(char *, struct zfcp_fsf_req *);
extern void zfcp_dbf_scsi_common(char *tag, int level, struct scsi_device *sdev,
struct scsi_cmnd *sc,
struct zfcp_fsf_req *fsf);
extern void zfcp_dbf_scsi_eh(char *tag, struct zfcp_adapter *adapter,
unsigned int scsi_id, int ret);
/* zfcp_erp.c */
extern void zfcp_erp_set_adapter_status(struct zfcp_adapter *, u32);
extern void zfcp_erp_clear_adapter_status(struct zfcp_adapter *, u32);
extern void zfcp_erp_port_forced_no_port_dbf(char *dbftag,
struct zfcp_adapter *adapter,
u64 port_name, u32 port_id);
extern void zfcp_erp_adapter_reopen(struct zfcp_adapter *, int, char *);
extern void zfcp_erp_adapter_shutdown(struct zfcp_adapter *, int, char *);
extern void zfcp_erp_set_port_status(struct zfcp_port *, u32);
extern void zfcp_erp_clear_port_status(struct zfcp_port *, u32);
extern void zfcp_erp_port_reopen(struct zfcp_port *port, int clear,
char *dbftag);
extern void zfcp_erp_port_shutdown(struct zfcp_port *, int, char *);
extern void zfcp_erp_port_forced_reopen(struct zfcp_port *, int, char *);
extern void zfcp_erp_port_forced_reopen_all(struct zfcp_adapter *adapter,
int clear, char *dbftag);
extern void zfcp_erp_set_lun_status(struct scsi_device *, u32);
extern void zfcp_erp_clear_lun_status(struct scsi_device *, u32);
extern void zfcp_erp_lun_reopen(struct scsi_device *, int, char *);
extern void zfcp_erp_lun_shutdown(struct scsi_device *, int, char *);
extern void zfcp_erp_lun_shutdown_wait(struct scsi_device *, char *);
extern int zfcp_erp_thread_setup(struct zfcp_adapter *);
extern void zfcp_erp_thread_kill(struct zfcp_adapter *);
extern void zfcp_erp_wait(struct zfcp_adapter *);
extern void zfcp_erp_notify(struct zfcp_erp_action *, unsigned long);
extern void zfcp_erp_timeout_handler(struct timer_list *t);
extern void zfcp_erp_adapter_reset_sync(struct zfcp_adapter *adapter,
char *dbftag);
/* zfcp_fc.c */
extern struct kmem_cache *zfcp_fc_req_cache;
extern void zfcp_fc_enqueue_event(struct zfcp_adapter *,
enum fc_host_event_code event_code, u32);
extern void zfcp_fc_post_event(struct work_struct *);
extern void zfcp_fc_scan_ports(struct work_struct *);
extern void zfcp_fc_incoming_els(struct zfcp_fsf_req *);
extern void zfcp_fc_port_did_lookup(struct work_struct *);
extern void zfcp_fc_trigger_did_lookup(struct zfcp_port *);
extern void zfcp_fc_plogi_evaluate(struct zfcp_port *, struct fc_els_flogi *);
extern void zfcp_fc_test_link(struct zfcp_port *);
extern void zfcp_fc_link_test_work(struct work_struct *);
extern void zfcp_fc_wka_ports_force_offline(struct zfcp_fc_wka_ports *);
extern int zfcp_fc_gs_setup(struct zfcp_adapter *);
extern void zfcp_fc_gs_destroy(struct zfcp_adapter *);
extern int zfcp_fc_exec_bsg_job(struct bsg_job *);
extern int zfcp_fc_timeout_bsg_job(struct bsg_job *);
extern void zfcp_fc_sym_name_update(struct work_struct *);
extern unsigned int zfcp_fc_port_scan_backoff(void);
extern void zfcp_fc_conditional_port_scan(struct zfcp_adapter *);
extern void zfcp_fc_inverse_conditional_port_scan(struct zfcp_adapter *);
/* zfcp_fsf.c */
extern struct kmem_cache *zfcp_fsf_qtcb_cache;
extern int zfcp_fsf_open_port(struct zfcp_erp_action *);
extern int zfcp_fsf_open_wka_port(struct zfcp_fc_wka_port *);
extern int zfcp_fsf_close_wka_port(struct zfcp_fc_wka_port *);
extern int zfcp_fsf_close_port(struct zfcp_erp_action *);
extern int zfcp_fsf_close_physical_port(struct zfcp_erp_action *);
extern int zfcp_fsf_open_lun(struct zfcp_erp_action *);
extern int zfcp_fsf_close_lun(struct zfcp_erp_action *);
extern int zfcp_fsf_exchange_config_data(struct zfcp_erp_action *);
extern int zfcp_fsf_exchange_config_data_sync(struct zfcp_qdio *,
struct fsf_qtcb_bottom_config *);
extern int zfcp_fsf_exchange_port_data(struct zfcp_erp_action *);
extern int zfcp_fsf_exchange_port_data_sync(struct zfcp_qdio *,
struct fsf_qtcb_bottom_port *);
extern void zfcp_fsf_req_dismiss_all(struct zfcp_adapter *);
extern int zfcp_fsf_status_read(struct zfcp_qdio *);
extern int zfcp_status_read_refill(struct zfcp_adapter *adapter);
extern int zfcp_fsf_send_ct(struct zfcp_fc_wka_port *, struct zfcp_fsf_ct_els *,
mempool_t *, unsigned int);
extern int zfcp_fsf_send_els(struct zfcp_adapter *, u32,
struct zfcp_fsf_ct_els *, unsigned int);
extern int zfcp_fsf_fcp_cmnd(struct scsi_cmnd *);
extern void zfcp_fsf_req_free(struct zfcp_fsf_req *);
extern struct zfcp_fsf_req *zfcp_fsf_fcp_task_mgmt(struct scsi_device *sdev,
u8 tm_flags);
extern struct zfcp_fsf_req *zfcp_fsf_abort_fcp_cmnd(struct scsi_cmnd *);
extern void zfcp_fsf_reqid_check(struct zfcp_qdio *, int);
/* zfcp_qdio.c */
extern int zfcp_qdio_setup(struct zfcp_adapter *);
extern void zfcp_qdio_destroy(struct zfcp_qdio *);
extern int zfcp_qdio_sbal_get(struct zfcp_qdio *);
extern int zfcp_qdio_send(struct zfcp_qdio *, struct zfcp_qdio_req *);
extern int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *, struct zfcp_qdio_req *,
struct scatterlist *);
extern int zfcp_qdio_open(struct zfcp_qdio *);
extern void zfcp_qdio_close(struct zfcp_qdio *);
extern void zfcp_qdio_siosl(struct zfcp_adapter *);
/* zfcp_scsi.c */
extern bool zfcp_experimental_dix;
extern struct scsi_transport_template *zfcp_scsi_transport_template;
extern int zfcp_scsi_adapter_register(struct zfcp_adapter *);
extern void zfcp_scsi_adapter_unregister(struct zfcp_adapter *);
extern struct fc_function_template zfcp_transport_functions;
extern void zfcp_scsi_rport_work(struct work_struct *);
extern void zfcp_scsi_schedule_rport_register(struct zfcp_port *);
extern void zfcp_scsi_schedule_rport_block(struct zfcp_port *);
extern void zfcp_scsi_schedule_rports_block(struct zfcp_adapter *);
extern void zfcp_scsi_set_prot(struct zfcp_adapter *);
extern void zfcp_scsi_dif_sense_error(struct scsi_cmnd *, int);
/* zfcp_sysfs.c */
extern const struct attribute_group *zfcp_unit_attr_groups[];
extern struct attribute_group zfcp_sysfs_adapter_attrs;
extern const struct attribute_group *zfcp_port_attr_groups[];
extern struct mutex zfcp_sysfs_port_units_mutex;
extern struct device_attribute *zfcp_sysfs_sdev_attrs[];
extern struct device_attribute *zfcp_sysfs_shost_attrs[];
bool zfcp_sysfs_port_is_removing(const struct zfcp_port *const port);
/* zfcp_unit.c */
extern int zfcp_unit_add(struct zfcp_port *, u64);
extern int zfcp_unit_remove(struct zfcp_port *, u64);
extern struct zfcp_unit *zfcp_unit_find(struct zfcp_port *, u64);
extern struct scsi_device *zfcp_unit_sdev(struct zfcp_unit *unit);
extern void zfcp_unit_scsi_scan(struct zfcp_unit *);
extern void zfcp_unit_queue_scsi_scan(struct zfcp_port *);
extern unsigned int zfcp_unit_sdev_status(struct zfcp_unit *);
#endif /* ZFCP_EXT_H */