Use xarray for device lookup by target. LUNs below 256 are linear,
and can be used directly as the index into the xarray.
LUNs above 256 have a distinct LUN format, and are not necessarily
linear. They'll be stored in indices above 256 in the xarray, with
the next free index in the xarray.
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
---
drivers/scsi/scsi.c | 35 +++++++++++++++++++++--------------
drivers/scsi/scsi_lib.c | 9 ++++-----
drivers/scsi/scsi_scan.c | 4 ++--
drivers/scsi/scsi_sysfs.c | 29 +++++++++++++++++++++++++++--
include/scsi/scsi_device.h | 4 ++--
5 files changed, 56 insertions(+), 25 deletions(-)
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index d601424e32b2..a3e01708744f 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -601,13 +601,14 @@ static struct scsi_target *__scsi_target_lookup(struct Scsi_Host *shost,
void starget_for_each_device(struct scsi_target *starget, void *data,
void (*fn)(struct scsi_device *, void *))
{
- struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
struct scsi_device *sdev;
+ unsigned long lun_idx = 0;
- shost_for_each_device(sdev, shost) {
- if ((sdev->channel == starget->channel) &&
- (sdev->id == starget->id))
- fn(sdev, data);
+ xa_for_each(&starget->__devices, lun_idx, sdev) {
+ if (scsi_device_get(sdev))
+ continue;
+ fn(sdev, data);
+ scsi_device_put(sdev);
}
}
EXPORT_SYMBOL(starget_for_each_device);
@@ -629,14 +630,11 @@ EXPORT_SYMBOL(starget_for_each_device);
void __starget_for_each_device(struct scsi_target *starget, void *data,
void (*fn)(struct scsi_device *, void *))
{
- struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
struct scsi_device *sdev;
+ unsigned long lun_idx = 0;
- __shost_for_each_device(sdev, shost) {
- if ((sdev->channel == starget->channel) &&
- (sdev->id == starget->id))
- fn(sdev, data);
- }
+ xa_for_each(&starget->__devices, lun_idx, sdev)
+ fn(sdev, data);
}
EXPORT_SYMBOL(__starget_for_each_device);
@@ -658,12 +656,21 @@ EXPORT_SYMBOL(__starget_for_each_device);
struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
u64 lun)
{
- struct scsi_device *sdev;
+ struct scsi_device *sdev = NULL;
+ unsigned long lun_idx = 0;
+
+ if (lun < UINT_MAX)
+ sdev = xa_load(&starget->__devices, lun);
+ if (sdev && sdev->lun == lun) {
+ if (sdev->sdev_state == SDEV_DEL)
+ sdev = NULL;
+ return sdev;
+ }
- list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
+ xa_for_each(&starget->__devices, lun_idx, sdev) {
if (sdev->sdev_state == SDEV_DEL)
continue;
- if (sdev->lun ==lun)
+ if (sdev->lun == lun)
return sdev;
}
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 06c260f6cdae..fc01591d32a8 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -372,9 +372,9 @@ static void scsi_kick_queue(struct request_queue *q)
static void scsi_single_lun_run(struct scsi_device *current_sdev)
{
struct Scsi_Host *shost = current_sdev->host;
- struct scsi_device *sdev, *tmp;
+ struct scsi_device *sdev;
struct scsi_target *starget = scsi_target(current_sdev);
- unsigned long flags;
+ unsigned long flags, lun_idx = 0;
spin_lock_irqsave(shost->host_lock, flags);
starget->starget_sdev_user = NULL;
@@ -391,8 +391,7 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev)
spin_lock_irqsave(shost->host_lock, flags);
if (starget->starget_sdev_user)
goto out;
- list_for_each_entry_safe(sdev, tmp, &starget->devices,
- same_target_siblings) {
+ xa_for_each(&starget->__devices, lun_idx, sdev) {
if (sdev == current_sdev)
continue;
if (scsi_device_get(sdev))
@@ -401,7 +400,7 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev)
spin_unlock_irqrestore(shost->host_lock, flags);
scsi_kick_queue(sdev->request_queue);
spin_lock_irqsave(shost->host_lock, flags);
-
+
scsi_device_put(sdev);
}
out:
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index b72265614a9b..e88ee895ab2a 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -235,7 +235,6 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
mutex_init(&sdev->state_mutex);
sdev->sdev_state = SDEV_CREATED;
INIT_LIST_HEAD(&sdev->siblings);
- INIT_LIST_HEAD(&sdev->same_target_siblings);
INIT_LIST_HEAD(&sdev->starved_entry);
INIT_LIST_HEAD(&sdev->event_list);
spin_lock_init(&sdev->list_lock);
@@ -327,6 +326,7 @@ static void scsi_target_dev_release(struct device *dev)
struct device *parent = dev->parent;
struct scsi_target *starget = to_scsi_target(dev);
+ xa_destroy(&starget->__devices);
kfree(starget);
put_device(parent);
}
@@ -414,7 +414,7 @@ static struct scsi_target *scsi_alloc_target(struct device *parent,
starget->id = id;
starget->channel = channel;
starget->can_queue = 0;
- INIT_LIST_HEAD(&starget->devices);
+ xa_init_flags(&starget->__devices, XA_FLAGS_ALLOC);
starget->state = STARGET_CREATED;
starget->scsi_level = SCSI_2;
starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index a694b25be5da..05a0111d4a6d 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -434,6 +434,7 @@ static void scsi_device_cls_release(struct device *class_dev)
static void scsi_device_dev_release_usercontext(struct work_struct *work)
{
struct scsi_device *sdev;
+ struct scsi_target *starget;
struct device *parent;
struct list_head *this, *tmp;
struct scsi_vpd *vpd_pg80 = NULL, *vpd_pg83 = NULL;
@@ -441,6 +442,7 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work)
unsigned long flags;
sdev = container_of(work, struct scsi_device, ew.work);
+ starget = sdev->sdev_target;
scsi_dh_release_device(sdev);
@@ -448,7 +450,7 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work)
spin_lock_irqsave(sdev->host->host_lock, flags);
list_del(&sdev->siblings);
- list_del(&sdev->same_target_siblings);
+ xa_erase(&starget->__devices, sdev->lun_idx);
list_del(&sdev->starved_entry);
spin_unlock_irqrestore(sdev->host->host_lock, flags);
@@ -1590,6 +1592,7 @@ void scsi_sysfs_device_initialize(struct scsi_device *sdev)
unsigned long flags;
struct Scsi_Host *shost = sdev->host;
struct scsi_target *starget = sdev->sdev_target;
+ int ret = -ERANGE;
device_initialize(&sdev->sdev_gendev);
sdev->sdev_gendev.bus = &scsi_bus_type;
@@ -1617,7 +1620,29 @@ void scsi_sysfs_device_initialize(struct scsi_device *sdev)
transport_setup_device(&sdev->sdev_gendev);
spin_lock_irqsave(shost->host_lock, flags);
- list_add_tail(&sdev->same_target_siblings, &starget->devices);
+ if (sdev->lun < 256) {
+ sdev->lun_idx = sdev->lun;
+ ret = xa_insert(&starget->__devices, (unsigned int)sdev->lun,
+ sdev, GFP_ATOMIC);
+ }
+ /*
+ * Use a free index if the LUN is larger than 32 bit or
+ * if the index is already taken. Leave the lower 256
+ * entries free to avoid collisions.
+ */
+ if (ret) {
+ struct xa_limit scsi_lun_limit = {
+ .min = 256,
+ .max = UINT_MAX,
+ };
+ ret = xa_alloc(&starget->__devices, &sdev->lun_idx,
+ sdev, scsi_lun_limit, GFP_ATOMIC);
+ }
+ if (ret) {
+ shost_printk(KERN_ERR, shost,
+ "LUN index %u:%u:%llu allocation error %d\n",
+ sdev_channel(sdev), sdev_id(sdev), sdev->lun, ret);
+ }
list_add_tail(&sdev->siblings, &shost->__devices);
spin_unlock_irqrestore(shost->host_lock, flags);
/*
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 8cb31bbd8a82..56801661f481 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -104,7 +104,6 @@ struct scsi_device {
/* the next two are protected by the host->host_lock */
struct list_head siblings; /* list of all devices on this host */
- struct list_head same_target_siblings; /* just the devices sharing same target id */
atomic_t device_busy; /* commands actually active on LLDD */
atomic_t device_blocked; /* Device returned QUEUE_FULL. */
@@ -123,6 +122,7 @@ struct scsi_device {
u16 id, channel;
u64 lun;
+ unsigned int lun_idx; /* Index into target device xarray */
unsigned int manufacturer; /* Manufacturer of device, for using
* vendor-specific cmd's */
unsigned sector_size; /* size in bytes */
@@ -285,7 +285,7 @@ enum scsi_target_state {
struct scsi_target {
struct scsi_device *starget_sdev_user;
struct list_head siblings;
- struct list_head devices;
+ struct xarray __devices;
struct device dev;
struct kref reap_ref; /* last put renders target invisible */
u16 channel;
--
2.16.4
