Introduce target_lock and device_lock to untangle the __devices and __targets
lists from the host_lock.
Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
---
drivers/scsi/53c700.c | 3 +++
drivers/scsi/hosts.c | 2 ++
drivers/scsi/scsi.c | 8 ++++----
drivers/scsi/scsi_scan.c | 10 +++++-----
drivers/scsi/scsi_sysfs.c | 18 ++++++++----------
include/scsi/scsi_host.h | 2 ++
6 files changed, 24 insertions(+), 19 deletions(-)
diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c
index a209c34..e2b4d04 100644
--- a/drivers/scsi/53c700.c
+++ b/drivers/scsi/53c700.c
@@ -1093,6 +1093,7 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp,
struct NCR_700_command_slot *slot;
__u8 reselection_id = hostdata->reselection_id;
struct scsi_device *SDp;
+ unsigned long flags;
lun = hostdata->msgin[0] & 0x1f;
@@ -1100,7 +1101,9 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp,
DEBUG(("scsi%d: (%d:%d) RESELECTED!\n",
host->host_no, reselection_id, lun));
/* clear the reselection indicator */
+ spin_lock_irqsave(host->device_lock, flags);
SDp = __scsi_device_lookup(host, 0, reselection_id, lun);
+ spin_unlock_irqrestore(host->device_lock, flags);
if(unlikely(SDp == NULL)) {
printk(KERN_ERR "scsi%d: (%d:%d) HAS NO device\n",
host->host_no, reselection_id, lun);
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 8bb173e..6855434 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -380,6 +380,8 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
shost->host_lock = &shost->default_lock;
spin_lock_init(shost->host_lock);
+ spin_lock_init(&shost->device_lock);
+ spin_lock_init(&shost->target_lock);
shost->shost_state = SHOST_CREATED;
INIT_LIST_HEAD(&shost->__devices);
INIT_LIST_HEAD(&shost->__targets);
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 207d6a7..0e1046a 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -970,7 +970,7 @@ struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
struct scsi_device *next = NULL;
unsigned long flags;
- spin_lock_irqsave(shost->host_lock, flags);
+ spin_lock_irqsave(&shost->device_lock, flags);
while (list->next != &shost->__devices) {
next = list_entry(list->next, struct scsi_device, siblings);
/* skip devices that we can't get a reference to */
@@ -979,7 +979,7 @@ struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
next = NULL;
list = list->next;
}
- spin_unlock_irqrestore(shost->host_lock, flags);
+ spin_unlock_irqrestore(&shost->device_lock, flags);
if (prev)
scsi_device_put(prev);
@@ -1144,11 +1144,11 @@ struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
struct scsi_device *sdev;
unsigned long flags;
- spin_lock_irqsave(shost->host_lock, flags);
+ spin_lock_irqsave(&shost->device_lock, flags);
sdev = __scsi_device_lookup(shost, channel, id, lun);
if (sdev && scsi_device_get(sdev))
sdev = NULL;
- spin_unlock_irqrestore(shost->host_lock, flags);
+ spin_unlock_irqrestore(&shost->device_lock, flags);
return sdev;
}
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index f9f3f82..ac68531 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -441,14 +441,14 @@ static struct scsi_target *scsi_alloc_target(struct device *parent,
starget->scsi_level = SCSI_2;
starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
retry:
- spin_lock_irqsave(shost->host_lock, flags);
+ spin_lock_irqsave(&shost->target_lock, flags);
found_target = __scsi_find_target(parent, channel, id);
if (found_target)
goto found;
list_add_tail(&starget->siblings, &shost->__targets);
- spin_unlock_irqrestore(shost->host_lock, flags);
+ spin_unlock_irqrestore(&shost->target_lock, flags);
/* allocate and add */
transport_setup_device(dev);
if (shost->hostt->target_alloc) {
@@ -1854,15 +1854,15 @@ void scsi_forget_host(struct Scsi_Host *shost)
unsigned long flags;
restart:
- spin_lock_irqsave(shost->host_lock, flags);
+ spin_lock_irqsave(&shost->device_lock, flags);
list_for_each_entry(sdev, &shost->__devices, siblings) {
if (sdev->sdev_state == SDEV_DEL)
continue;
- spin_unlock_irqrestore(shost->host_lock, flags);
+ spin_unlock_irqrestore(&shost->device_lock, flags);
__scsi_remove_device(sdev);
goto restart;
}
- spin_unlock_irqrestore(shost->host_lock, flags);
+ spin_unlock_irqrestore(&shost->device_lock, flags);
}
/**
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index b333389..d7afea9 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1131,20 +1131,18 @@ static void __scsi_remove_target(struct scsi_target *starget)
unsigned long flags;
struct scsi_device *sdev;
- spin_lock_irqsave(shost->host_lock, flags);
+ spin_lock_irqsave(&shost->device_lock, flags);
restart:
list_for_each_entry(sdev, &shost->__devices, siblings) {
if (sdev->channel != starget->channel ||
sdev->id != starget->id ||
scsi_device_get(sdev))
continue;
- spin_unlock_irqrestore(shost->host_lock, flags);
scsi_remove_device(sdev);
scsi_device_put(sdev);
- spin_lock_irqsave(shost->host_lock, flags);
goto restart;
}
- spin_unlock_irqrestore(shost->host_lock, flags);
+ spin_unlock_irqrestore(&shost->device_lock, flags);
}
/**
@@ -1164,22 +1162,22 @@ void scsi_remove_target(struct device *dev)
/* remove targets being careful to lookup next entry before
* deleting the last
*/
- spin_lock_irqsave(shost->host_lock, flags);
+ spin_lock_irqsave(&shost->target_lock, flags);
list_for_each_entry(starget, &shost->__targets, siblings) {
if (starget->state == STARGET_DEL)
continue;
if (starget->dev.parent == dev || &starget->dev == dev) {
/* assuming new targets arrive at the end */
kref_get(&starget->reap_ref);
- spin_unlock_irqrestore(shost->host_lock, flags);
+ spin_unlock_irqrestore(&shost->target_lock, flags);
if (last)
scsi_target_reap(last);
last = starget;
__scsi_remove_target(starget);
- spin_lock_irqsave(shost->host_lock, flags);
+ spin_lock_irqsave(&shost->target_lock, flags);
}
}
- spin_unlock_irqrestore(shost->host_lock, flags);
+ spin_unlock_irqrestore(&shost->target_lock, flags);
if (last)
scsi_target_reap(last);
@@ -1262,10 +1260,10 @@ void scsi_sysfs_device_initialize(struct scsi_device *sdev)
sdev->lun_in_cdb = 1;
transport_setup_device(&sdev->sdev_gendev);
- spin_lock_irqsave(shost->host_lock, flags);
+ spin_lock_irqsave(&shost->device_lock, flags);
list_add_tail(&sdev->same_target_siblings, &starget->devices);
list_add_tail(&sdev->siblings, &shost->__devices);
- spin_unlock_irqrestore(shost->host_lock, flags);
+ spin_unlock_irqrestore(&shost->device_lock, flags);
/*
* device can now only be removed via __scsi_remove_device() so hold
* the target. Target will be held in CREATED state until something
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index e113c75..764020a 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -558,6 +558,8 @@ struct Scsi_Host {
spinlock_t default_lock;
spinlock_t *host_lock;
+ spinlock_t device_lock; /* protects the __devices list */
+ spinlock_t target_lock; /* protects the __targets list */
struct mutex scan_mutex;/* serialize scanning activity */
--
1.8.5.6
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