From d3301874083874f8a0ac88aa1bb7da6b62df34d2 Mon Sep 17 00:00:00 2001 From: Mike Anderson Date: Thu, 16 Jun 2005 11:12:38 -0700 Subject: [SCSI] host state model update: replace old host bitmap state Migrate the current SCSI host state model to a model like SCSI device is using. Signed-off-by: Mike Anderson Rejections fixed up and Signed-off-by: James Bottomley --- drivers/scsi/hosts.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 82 insertions(+), 6 deletions(-) (limited to 'drivers/scsi/hosts.c') diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 5feb886c339..6828ca305c2 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -51,6 +51,82 @@ static struct class shost_class = { .release = scsi_host_cls_release, }; +/** + * scsi_host_set_state - Take the given host through the host + * state model. + * @shost: scsi host to change the state of. + * @state: state to change to. + * + * Returns zero if unsuccessful or an error if the requested + * transition is illegal. + **/ +int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) +{ + enum scsi_host_state oldstate = shost->shost_state; + + if (state == oldstate) + return 0; + + switch (state) { + case SHOST_CREATED: + /* There are no legal states that come back to + * created. This is the manually initialised start + * state */ + goto illegal; + + case SHOST_RUNNING: + switch (oldstate) { + case SHOST_CREATED: + case SHOST_RECOVERY: + break; + default: + goto illegal; + } + break; + + case SHOST_RECOVERY: + switch (oldstate) { + case SHOST_RUNNING: + break; + default: + goto illegal; + } + break; + + case SHOST_CANCEL: + switch (oldstate) { + case SHOST_CREATED: + case SHOST_RUNNING: + break; + default: + goto illegal; + } + break; + + case SHOST_DEL: + switch (oldstate) { + case SHOST_CANCEL: + break; + default: + goto illegal; + } + break; + + } + shost->shost_state = state; + return 0; + + illegal: + SCSI_LOG_ERROR_RECOVERY(1, + dev_printk(KERN_ERR, &shost->shost_gendev, + "Illegal host state transition" + "%s->%s\n", + scsi_host_state_name(oldstate), + scsi_host_state_name(state))); + return -EINVAL; +} +EXPORT_SYMBOL(scsi_host_set_state); + /** * scsi_host_cancel - cancel outstanding IO to this host * @shost: pointer to struct Scsi_Host @@ -60,12 +136,11 @@ static void scsi_host_cancel(struct Scsi_Host *shost, int recovery) { struct scsi_device *sdev; - set_bit(SHOST_CANCEL, &shost->shost_state); + scsi_host_set_state(shost, SHOST_CANCEL); shost_for_each_device(sdev, shost) { scsi_device_cancel(sdev, recovery); } - wait_event(shost->host_wait, (!test_bit(SHOST_RECOVERY, - &shost->shost_state))); + wait_event(shost->host_wait, (shost->shost_state != SHOST_RECOVERY)); } /** @@ -78,7 +153,7 @@ void scsi_remove_host(struct Scsi_Host *shost) scsi_host_cancel(shost, 0); scsi_proc_host_rm(shost); - set_bit(SHOST_DEL, &shost->shost_state); + scsi_host_set_state(shost, SHOST_DEL); transport_unregister_device(&shost->shost_gendev); class_device_unregister(&shost->shost_classdev); @@ -115,7 +190,7 @@ int scsi_add_host(struct Scsi_Host *shost, struct device *dev) if (error) goto out; - set_bit(SHOST_ADD, &shost->shost_state); + scsi_host_set_state(shost, SHOST_RUNNING); get_device(shost->shost_gendev.parent); error = class_device_add(&shost->shost_classdev); @@ -226,6 +301,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) spin_lock_init(&shost->default_lock); scsi_assign_lock(shost, &shost->default_lock); + shost->shost_state = SHOST_CREATED; INIT_LIST_HEAD(&shost->__devices); INIT_LIST_HEAD(&shost->__targets); INIT_LIST_HEAD(&shost->eh_cmd_q); @@ -382,7 +458,7 @@ EXPORT_SYMBOL(scsi_host_lookup); **/ struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) { - if (test_bit(SHOST_DEL, &shost->shost_state) || + if ((shost->shost_state == SHOST_DEL) || !get_device(&shost->shost_gendev)) return NULL; return shost; -- cgit v1.2.3-70-g09d2 From d2c9d9eafa03dbd08a8a439e6c5addb8b1f03b9b Mon Sep 17 00:00:00 2001 From: Mike Anderson Date: Thu, 16 Jun 2005 11:13:42 -0700 Subject: [SCSI] host state model update: reimplement scsi_host_cancel Remove the old scsi_host_cancel function as it has not been working for sometime do to the device list possibly being empty when it is called and possible race issues. Add setting of SHOST_CANCEL at the state of beginning of scsi_remove_host. Signed-off-by: Mike Anderson Signed-off-by: James Bottomley --- drivers/scsi/hosts.c | 18 +----------------- drivers/scsi/scsi.c | 2 +- 2 files changed, 2 insertions(+), 18 deletions(-) (limited to 'drivers/scsi/hosts.c') diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 6828ca305c2..67c4c0c3aa5 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -127,30 +127,14 @@ int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) } EXPORT_SYMBOL(scsi_host_set_state); -/** - * scsi_host_cancel - cancel outstanding IO to this host - * @shost: pointer to struct Scsi_Host - * recovery: recovery requested to run. - **/ -static void scsi_host_cancel(struct Scsi_Host *shost, int recovery) -{ - struct scsi_device *sdev; - - scsi_host_set_state(shost, SHOST_CANCEL); - shost_for_each_device(sdev, shost) { - scsi_device_cancel(sdev, recovery); - } - wait_event(shost->host_wait, (shost->shost_state != SHOST_RECOVERY)); -} - /** * scsi_remove_host - remove a scsi host * @shost: a pointer to a scsi host to remove **/ void scsi_remove_host(struct Scsi_Host *shost) { + scsi_host_set_state(shost, SHOST_CANCEL); scsi_forget_host(shost); - scsi_host_cancel(shost, 0); scsi_proc_host_rm(shost); scsi_host_set_state(shost, SHOST_DEL); diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index fb85b3ced7b..d1aa95d45a7 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -627,7 +627,7 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd) spin_lock_irqsave(host->host_lock, flags); scsi_cmd_get_serial(host, cmd); - if (unlikely(host->shost_state == SHOST_CANCEL)) { + if (unlikely(host->shost_state == SHOST_DEL)) { cmd->result = (DID_NO_CONNECT << 16); scsi_done(cmd); } else { -- cgit v1.2.3-70-g09d2 From 82f29467a025f6a2192d281e97fca0be46e905cc Mon Sep 17 00:00:00 2001 From: Mike Anderson Date: Thu, 16 Jun 2005 11:14:33 -0700 Subject: [SCSI] host state model update: mediate host add/remove race Add support to not allow additions to a host when it is being removed. Signed-off-by: Mike Anderson Signed-off-by: James Bottomley --- drivers/scsi/hosts.c | 2 ++ drivers/scsi/scsi_scan.c | 21 ++++++++++++++------- include/scsi/scsi_host.h | 9 +++++++++ 3 files changed, 25 insertions(+), 7 deletions(-) (limited to 'drivers/scsi/hosts.c') diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 67c4c0c3aa5..8640ad1c17e 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -133,7 +133,9 @@ EXPORT_SYMBOL(scsi_host_set_state); **/ void scsi_remove_host(struct Scsi_Host *shost) { + down(&shost->scan_mutex); scsi_host_set_state(shost, SHOST_CANCEL); + up(&shost->scan_mutex); scsi_forget_host(shost); scsi_proc_host_rm(shost); diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 2d3c4ac475f..076cbe3b5a0 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -1251,9 +1251,12 @@ struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, get_device(&starget->dev); down(&shost->scan_mutex); - res = scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata); - if (res != SCSI_SCAN_LUN_PRESENT) - sdev = ERR_PTR(-ENODEV); + if (scsi_host_scan_allowed(shost)) { + res = scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, + hostdata); + if (res != SCSI_SCAN_LUN_PRESENT) + sdev = ERR_PTR(-ENODEV); + } up(&shost->scan_mutex); scsi_target_reap(starget); put_device(&starget->dev); @@ -1403,11 +1406,15 @@ int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, return -EINVAL; down(&shost->scan_mutex); - if (channel == SCAN_WILD_CARD) - for (channel = 0; channel <= shost->max_channel; channel++) + if (scsi_host_scan_allowed(shost)) { + if (channel == SCAN_WILD_CARD) + for (channel = 0; channel <= shost->max_channel; + channel++) + scsi_scan_channel(shost, channel, id, lun, + rescan); + else scsi_scan_channel(shost, channel, id, lun, rescan); - else - scsi_scan_channel(shost, channel, id, lun, rescan); + } up(&shost->scan_mutex); return 0; diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 0b1e275b269..1ea5b51d174 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -650,6 +650,15 @@ static inline struct device *scsi_get_device(struct Scsi_Host *shost) return shost->shost_gendev.parent; } +/** + * scsi_host_scan_allowed - Is scanning of this host allowed + * @shost: Pointer to Scsi_Host. + **/ +static inline int scsi_host_scan_allowed(struct Scsi_Host *shost) +{ + return shost->shost_state == SHOST_RUNNING; +} + extern void scsi_unblock_requests(struct Scsi_Host *); extern void scsi_block_requests(struct Scsi_Host *); -- cgit v1.2.3-70-g09d2 From c5478def7a3a2dba9ceda452c2aa3539514d30a9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 6 Sep 2005 14:04:26 +0200 Subject: [SCSI] switch EH thread startup to the kthread API Signed-off-by: James Bottomley --- drivers/scsi/hosts.c | 23 ++++++++--------------- drivers/scsi/scsi_error.c | 29 ++--------------------------- include/scsi/scsi_host.h | 2 -- 3 files changed, 10 insertions(+), 44 deletions(-) (limited to 'drivers/scsi/hosts.c') diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 8640ad1c17e..85503fad789 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -225,15 +226,8 @@ static void scsi_host_dev_release(struct device *dev) struct Scsi_Host *shost = dev_to_shost(dev); struct device *parent = dev->parent; - if (shost->ehandler) { - DECLARE_COMPLETION(sem); - shost->eh_notify = &sem; - shost->eh_kill = 1; - up(shost->eh_wait); - wait_for_completion(&sem); - shost->eh_notify = NULL; - } - + if (shost->ehandler) + kthread_stop(shost->ehandler); if (shost->work_q) destroy_workqueue(shost->work_q); @@ -263,7 +257,6 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) { struct Scsi_Host *shost; int gfp_mask = GFP_KERNEL, rval; - DECLARE_COMPLETION(complete); if (sht->unchecked_isa_dma && privsize) gfp_mask |= __GFP_DMA; @@ -369,12 +362,12 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d", shost->host_no); - shost->eh_notify = &complete; - rval = kernel_thread(scsi_error_handler, shost, 0); - if (rval < 0) + shost->ehandler = kthread_run(scsi_error_handler, shost, + "scsi_eh_%d", shost->host_no); + if (IS_ERR(shost->ehandler)) { + rval = PTR_ERR(shost->ehandler); goto fail_destroy_freelist; - wait_for_completion(&complete); - shost->eh_notify = NULL; + } scsi_proc_hostdir_add(shost->hostt); return shost; diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 688bce74078..ebe74ccb518 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -1585,16 +1586,8 @@ int scsi_error_handler(void *data) int rtn; DECLARE_MUTEX_LOCKED(sem); - /* - * Flush resources - */ - - daemonize("scsi_eh_%d", shost->host_no); - current->flags |= PF_NOFREEZE; - shost->eh_wait = &sem; - shost->ehandler = current; /* * Wake up the thread that created us. @@ -1602,8 +1595,6 @@ int scsi_error_handler(void *data) SCSI_LOG_ERROR_RECOVERY(3, printk("Wake up parent of" " scsi_eh_%d\n",shost->host_no)); - complete(shost->eh_notify); - while (1) { /* * If we get a signal, it means we are supposed to go @@ -1624,7 +1615,7 @@ int scsi_error_handler(void *data) * semaphores isn't unreasonable. */ down_interruptible(&sem); - if (shost->eh_kill) + if (kthread_should_stop()) break; SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler" @@ -1663,22 +1654,6 @@ int scsi_error_handler(void *data) * Make sure that nobody tries to wake us up again. */ shost->eh_wait = NULL; - - /* - * Knock this down too. From this point on, the host is flying - * without a pilot. If this is because the module is being unloaded, - * that's fine. If the user sent a signal to this thing, we are - * potentially in real danger. - */ - shost->eh_active = 0; - shost->ehandler = NULL; - - /* - * If anyone is waiting for us to exit (i.e. someone trying to unload - * a driver), then wake up that process to let them know we are on - * the way out the door. - */ - complete_and_exit(shost->eh_notify, 0); return 0; } diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index ac1b6125e3a..916144be208 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -467,12 +467,10 @@ struct Scsi_Host { struct task_struct * ehandler; /* Error recovery thread. */ struct semaphore * eh_wait; /* The error recovery thread waits on this. */ - struct completion * eh_notify; /* wait for eh to begin or end */ struct semaphore * eh_action; /* Wait for specific actions on the host. */ unsigned int eh_active:1; /* Indicates the eh thread is awake and active if this is true. */ - unsigned int eh_kill:1; /* set when killing the eh thread */ wait_queue_head_t host_wait; struct scsi_host_template *hostt; struct scsi_transport_template *transportt; -- cgit v1.2.3-70-g09d2