[PATCH 2/6] scsi: use container_of to get at device handler private data

From: Christoph Hellwig
Date: Sun Oct 19 2014 - 11:58:41 EST


Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/scsi/device_handler/scsi_dh_alua.c | 25 +++++++++----------------
drivers/scsi/device_handler/scsi_dh_emc.c | 24 ++++++++++--------------
drivers/scsi/device_handler/scsi_dh_hp_sw.c | 23 +++++++++--------------
drivers/scsi/device_handler/scsi_dh_rdac.c | 25 +++++++++----------------
include/scsi/scsi_device.h | 1 -
5 files changed, 37 insertions(+), 61 deletions(-)

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 45b1795..40a2b0e 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -62,6 +62,7 @@
#define ALUA_OPTIMIZE_STPG 1

struct alua_dh_data {
+ struct scsi_dh_data dh_data;
int group_id;
int rel_port;
int tpgs;
@@ -87,9 +88,7 @@ static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *);

static inline struct alua_dh_data *get_alua_data(struct scsi_device *sdev)
{
- struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
- BUG_ON(scsi_dh_data == NULL);
- return ((struct alua_dh_data *) scsi_dh_data->buf);
+ return container_of(sdev->scsi_dh_data, struct alua_dh_data, dh_data);
}

static int realloc_buffer(struct alua_dh_data *h, unsigned len)
@@ -839,21 +838,18 @@ static struct scsi_device_handler alua_dh = {
*/
static int alua_bus_attach(struct scsi_device *sdev)
{
- struct scsi_dh_data *scsi_dh_data;
struct alua_dh_data *h;
unsigned long flags;
int err = SCSI_DH_OK;

- scsi_dh_data = kzalloc(sizeof(*scsi_dh_data)
- + sizeof(*h) , GFP_KERNEL);
- if (!scsi_dh_data) {
+ h = kzalloc(sizeof(*h) , GFP_KERNEL);
+ if (!h) {
sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
ALUA_DH_NAME);
return -ENOMEM;
}

- scsi_dh_data->scsi_dh = &alua_dh;
- h = (struct alua_dh_data *) scsi_dh_data->buf;
+ h->dh_data.scsi_dh = &alua_dh;
h->tpgs = TPGS_MODE_UNINITIALIZED;
h->state = TPGS_STATE_OPTIMIZED;
h->group_id = -1;
@@ -867,14 +863,14 @@ static int alua_bus_attach(struct scsi_device *sdev)
goto failed;

spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
- sdev->scsi_dh_data = scsi_dh_data;
+ sdev->scsi_dh_data = &h->dh_data;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
sdev_printk(KERN_NOTICE, sdev, "%s: Attached\n", ALUA_DH_NAME);

return 0;

failed:
- kfree(scsi_dh_data);
+ kfree(h);
sdev_printk(KERN_ERR, sdev, "%s: not attached\n", ALUA_DH_NAME);
return -EINVAL;
}
@@ -885,19 +881,16 @@ failed:
*/
static void alua_bus_detach(struct scsi_device *sdev)
{
- struct scsi_dh_data *scsi_dh_data;
- struct alua_dh_data *h;
+ struct alua_dh_data *h = get_alua_data(sdev);
unsigned long flags;

spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
- scsi_dh_data = sdev->scsi_dh_data;
sdev->scsi_dh_data = NULL;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);

- h = (struct alua_dh_data *) scsi_dh_data->buf;
if (h->buff && h->inq != h->buff)
kfree(h->buff);
- kfree(scsi_dh_data);
+ kfree(h);
sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", ALUA_DH_NAME);
}

diff --git a/drivers/scsi/device_handler/scsi_dh_emc.c b/drivers/scsi/device_handler/scsi_dh_emc.c
index 153b4c3..c2e26cd 100644
--- a/drivers/scsi/device_handler/scsi_dh_emc.c
+++ b/drivers/scsi/device_handler/scsi_dh_emc.c
@@ -72,6 +72,7 @@ static const char * lun_state[] =
};

struct clariion_dh_data {
+ struct scsi_dh_data dh_data;
/*
* Flags:
* CLARIION_SHORT_TRESPASS
@@ -116,9 +117,8 @@ struct clariion_dh_data {
static inline struct clariion_dh_data
*get_clariion_data(struct scsi_device *sdev)
{
- struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
- BUG_ON(scsi_dh_data == NULL);
- return ((struct clariion_dh_data *) scsi_dh_data->buf);
+ return container_of(sdev->scsi_dh_data, struct clariion_dh_data,
+ dh_data);
}

/*
@@ -665,21 +665,18 @@ static struct scsi_device_handler clariion_dh = {

static int clariion_bus_attach(struct scsi_device *sdev)
{
- struct scsi_dh_data *scsi_dh_data;
struct clariion_dh_data *h;
unsigned long flags;
int err;

- scsi_dh_data = kzalloc(sizeof(*scsi_dh_data)
- + sizeof(*h) , GFP_KERNEL);
- if (!scsi_dh_data) {
+ h = kzalloc(sizeof(*h) , GFP_KERNEL);
+ if (!h) {
sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
CLARIION_NAME);
return -ENOMEM;
}

- scsi_dh_data->scsi_dh = &clariion_dh;
- h = (struct clariion_dh_data *) scsi_dh_data->buf;
+ h->dh_data.scsi_dh = &clariion_dh;
h->lun_state = CLARIION_LUN_UNINITIALIZED;
h->default_sp = CLARIION_UNBOUND_LU;
h->current_sp = CLARIION_UNBOUND_LU;
@@ -693,7 +690,7 @@ static int clariion_bus_attach(struct scsi_device *sdev)
goto failed;

spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
- sdev->scsi_dh_data = scsi_dh_data;
+ sdev->scsi_dh_data = &h->dh_data;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);

sdev_printk(KERN_INFO, sdev,
@@ -705,7 +702,7 @@ static int clariion_bus_attach(struct scsi_device *sdev)
return 0;

failed:
- kfree(scsi_dh_data);
+ kfree(h);
sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
CLARIION_NAME);
return -EINVAL;
@@ -713,18 +710,17 @@ failed:

static void clariion_bus_detach(struct scsi_device *sdev)
{
- struct scsi_dh_data *scsi_dh_data;
+ struct clariion_dh_data *h = get_clariion_data(sdev);
unsigned long flags;

spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
- scsi_dh_data = sdev->scsi_dh_data;
sdev->scsi_dh_data = NULL;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);

sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n",
CLARIION_NAME);

- kfree(scsi_dh_data);
+ kfree(h);
}

static int __init clariion_init(void)
diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
index 367e6f5..040998c 100644
--- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c
+++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
@@ -38,6 +38,7 @@
#define HP_SW_PATH_PASSIVE 1

struct hp_sw_dh_data {
+ struct scsi_dh_data dh_data;
unsigned char sense[SCSI_SENSE_BUFFERSIZE];
int path_state;
int retries;
@@ -51,9 +52,7 @@ static int hp_sw_start_stop(struct hp_sw_dh_data *);

static inline struct hp_sw_dh_data *get_hp_sw_data(struct scsi_device *sdev)
{
- struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
- BUG_ON(scsi_dh_data == NULL);
- return ((struct hp_sw_dh_data *) scsi_dh_data->buf);
+ return container_of(sdev->scsi_dh_data, struct hp_sw_dh_data, dh_data);
}

/*
@@ -354,21 +353,18 @@ static struct scsi_device_handler hp_sw_dh = {

static int hp_sw_bus_attach(struct scsi_device *sdev)
{
- struct scsi_dh_data *scsi_dh_data;
struct hp_sw_dh_data *h;
unsigned long flags;
int ret;

- scsi_dh_data = kzalloc(sizeof(*scsi_dh_data)
- + sizeof(*h) , GFP_KERNEL);
- if (!scsi_dh_data) {
+ h = kzalloc(sizeof(*h), GFP_KERNEL);
+ if (!h) {
sdev_printk(KERN_ERR, sdev, "%s: Attach Failed\n",
HP_SW_NAME);
return 0;
}

- scsi_dh_data->scsi_dh = &hp_sw_dh;
- h = (struct hp_sw_dh_data *) scsi_dh_data->buf;
+ h->dh_data.scsi_dh = &hp_sw_dh;
h->path_state = HP_SW_PATH_UNINITIALIZED;
h->retries = HP_SW_RETRIES;
h->sdev = sdev;
@@ -378,7 +374,7 @@ static int hp_sw_bus_attach(struct scsi_device *sdev)
goto failed;

spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
- sdev->scsi_dh_data = scsi_dh_data;
+ sdev->scsi_dh_data = &h->dh_data;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);

sdev_printk(KERN_INFO, sdev, "%s: attached to %s path\n",
@@ -388,7 +384,7 @@ static int hp_sw_bus_attach(struct scsi_device *sdev)
return 0;

failed:
- kfree(scsi_dh_data);
+ kfree(h);
sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
HP_SW_NAME);
return -EINVAL;
@@ -396,17 +392,16 @@ failed:

static void hp_sw_bus_detach( struct scsi_device *sdev )
{
- struct scsi_dh_data *scsi_dh_data;
+ struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
unsigned long flags;

spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
- scsi_dh_data = sdev->scsi_dh_data;
sdev->scsi_dh_data = NULL;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);

sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", HP_SW_NAME);

- kfree(scsi_dh_data);
+ kfree(h);
}

static int __init hp_sw_init(void)
diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
index b850954..ef8caaa 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -181,6 +181,7 @@ struct c2_inquiry {
};

struct rdac_dh_data {
+ struct scsi_dh_data dh_data;
struct rdac_controller *ctlr;
#define UNINITIALIZED_LUN (1 << 8)
unsigned lun;
@@ -261,9 +262,7 @@ do { \

static inline struct rdac_dh_data *get_rdac_data(struct scsi_device *sdev)
{
- struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
- BUG_ON(scsi_dh_data == NULL);
- return ((struct rdac_dh_data *) scsi_dh_data->buf);
+ return container_of(sdev->scsi_dh_data, struct rdac_dh_data, dh_data);
}

static struct request *get_rdac_req(struct scsi_device *sdev,
@@ -842,23 +841,20 @@ static struct scsi_device_handler rdac_dh = {

static int rdac_bus_attach(struct scsi_device *sdev)
{
- struct scsi_dh_data *scsi_dh_data;
struct rdac_dh_data *h;
unsigned long flags;
int err;
char array_name[ARRAY_LABEL_LEN];
char array_id[UNIQUE_ID_LEN];

- scsi_dh_data = kzalloc(sizeof(*scsi_dh_data)
- + sizeof(*h) , GFP_KERNEL);
- if (!scsi_dh_data) {
+ h = kzalloc(sizeof(*h) , GFP_KERNEL);
+ if (!h) {
sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
RDAC_NAME);
return -ENOMEM;
}

- scsi_dh_data->scsi_dh = &rdac_dh;
- h = (struct rdac_dh_data *) scsi_dh_data->buf;
+ h->dh_data.scsi_dh = &rdac_dh;
h->lun = UNINITIALIZED_LUN;
h->state = RDAC_STATE_ACTIVE;

@@ -879,7 +875,7 @@ static int rdac_bus_attach(struct scsi_device *sdev)
goto clean_ctlr;

spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
- sdev->scsi_dh_data = scsi_dh_data;
+ sdev->scsi_dh_data = &h->dh_data;
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);

sdev_printk(KERN_NOTICE, sdev,
@@ -895,7 +891,7 @@ clean_ctlr:
spin_unlock(&list_lock);

failed:
- kfree(scsi_dh_data);
+ kfree(h);
sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
RDAC_NAME);
return -EINVAL;
@@ -903,12 +899,9 @@ failed:

static void rdac_bus_detach( struct scsi_device *sdev )
{
- struct scsi_dh_data *scsi_dh_data;
- struct rdac_dh_data *h;
+ struct rdac_dh_data *h = get_rdac_data(sdev);
unsigned long flags;

- scsi_dh_data = sdev->scsi_dh_data;
- h = (struct rdac_dh_data *) scsi_dh_data->buf;
if (h->ctlr && h->ctlr->ms_queued)
flush_workqueue(kmpath_rdacd);

@@ -920,7 +913,7 @@ static void rdac_bus_detach( struct scsi_device *sdev )
if (h->ctlr)
kref_put(&h->ctlr->kref, release_controller);
spin_unlock(&list_lock);
- kfree(scsi_dh_data);
+ kfree(h);
sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME);
}

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 27ecee7..fb46864 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -228,7 +228,6 @@ struct scsi_dh_data {
struct scsi_device_handler *scsi_dh;
struct scsi_device *sdev;
struct kref kref;
- char buf[0];
};

#define to_scsi_device(d) \
--
1.9.1

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