[patch 9/24] s390: use normal switch statement for ioctls in dasd_ioctl.c.

From: Martin Schwidefsky
Date: Wed Mar 22 2006 - 10:15:01 EST


From: Christoph Hellwig <hch@xxxxxx>

[patch 9/24] s390: use normal switch statement for ioctls in dasd_ioctl.c.

Handle ioctls implemented in dasd_ioctl through the normal switch
statement that most drivers use instead of the awkward
dasd_ioctl_no_register routine. This avoids searching a linear list
on every call to dasd_ioctl(), and allows to give the various ioctl
implementation functions sane prototypes, aswell as moving the
check for bdev->bd_disk->private_data from the individual functions
to dasd_ioctl. (I think it can't actually every be NULL, but let's keep
that for later)

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---

drivers/s390/block/dasd.c | 4
drivers/s390/block/dasd_int.h | 2
drivers/s390/block/dasd_ioctl.c | 241 ++++++++++++++--------------------------
3 files changed, 86 insertions(+), 161 deletions(-)

diff -urpN linux-2.6/drivers/s390/block/dasd.c linux-2.6-patched/drivers/s390/block/dasd.c
--- linux-2.6/drivers/s390/block/dasd.c 2006-03-20 06:53:29.000000000 +0100
+++ linux-2.6-patched/drivers/s390/block/dasd.c 2006-03-22 14:36:18.000000000 +0100
@@ -1807,7 +1807,6 @@ dasd_exit(void)
#ifdef CONFIG_PROC_FS
dasd_proc_exit();
#endif
- dasd_ioctl_exit();
if (dasd_page_cache != NULL) {
kmem_cache_destroy(dasd_page_cache);
dasd_page_cache = NULL;
@@ -2093,9 +2092,6 @@ dasd_init(void)
rc = dasd_parse();
if (rc)
goto failed;
- rc = dasd_ioctl_init();
- if (rc)
- goto failed;
#ifdef CONFIG_PROC_FS
rc = dasd_proc_init();
if (rc)
diff -urpN linux-2.6/drivers/s390/block/dasd_int.h linux-2.6-patched/drivers/s390/block/dasd_int.h
--- linux-2.6/drivers/s390/block/dasd_int.h 2006-03-20 06:53:29.000000000 +0100
+++ linux-2.6-patched/drivers/s390/block/dasd_int.h 2006-03-22 14:36:18.000000000 +0100
@@ -523,8 +523,6 @@ int dasd_scan_partitions(struct dasd_dev
void dasd_destroy_partitions(struct dasd_device *);

/* externals in dasd_ioctl.c */
-int dasd_ioctl_init(void);
-void dasd_ioctl_exit(void);
int dasd_ioctl_no_register(struct module *, int, dasd_ioctl_fn_t);
int dasd_ioctl_no_unregister(struct module *, int, dasd_ioctl_fn_t);
int dasd_ioctl(struct inode *, struct file *, unsigned int, unsigned long);
diff -urpN linux-2.6/drivers/s390/block/dasd_ioctl.c linux-2.6-patched/drivers/s390/block/dasd_ioctl.c
--- linux-2.6/drivers/s390/block/dasd_ioctl.c 2006-03-20 06:53:29.000000000 +0100
+++ linux-2.6-patched/drivers/s390/block/dasd_ioctl.c 2006-03-22 14:36:18.000000000 +0100
@@ -77,62 +77,11 @@ dasd_ioctl_no_unregister(struct module *
return 0;
}

-int
-dasd_ioctl(struct inode *inp, struct file *filp,
- unsigned int no, unsigned long data)
-{
- struct block_device *bdev = inp->i_bdev;
- struct dasd_device *device = bdev->bd_disk->private_data;
- struct dasd_ioctl *ioctl;
- const char *dir;
- int rc;
-
- if ((_IOC_DIR(no) != _IOC_NONE) && (data == 0)) {
- PRINT_DEBUG("empty data ptr");
- return -EINVAL;
- }
- dir = _IOC_DIR (no) == _IOC_NONE ? "0" :
- _IOC_DIR (no) == _IOC_READ ? "r" :
- _IOC_DIR (no) == _IOC_WRITE ? "w" :
- _IOC_DIR (no) == (_IOC_READ | _IOC_WRITE) ? "rw" : "u";
- DBF_DEV_EVENT(DBF_DEBUG, device,
- "ioctl 0x%08x %s'0x%x'%d(%d) with data %8lx", no,
- dir, _IOC_TYPE(no), _IOC_NR(no), _IOC_SIZE(no), data);
- /* Search for ioctl no in the ioctl list. */
- list_for_each_entry(ioctl, &dasd_ioctl_list, list) {
- if (ioctl->no == no) {
- /* Found a matching ioctl. Call it. */
- if (!try_module_get(ioctl->owner))
- continue;
- rc = ioctl->handler(bdev, no, data);
- module_put(ioctl->owner);
- return rc;
- }
- }
- /* No ioctl with number no. */
- DBF_DEV_EVENT(DBF_INFO, device,
- "unknown ioctl 0x%08x=%s'0x%x'%d(%d) data %8lx", no,
- dir, _IOC_TYPE(no), _IOC_NR(no), _IOC_SIZE(no), data);
- return -EINVAL;
-}
-
-long
-dasd_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
-{
- int rval;
-
- lock_kernel();
- rval = dasd_ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
- unlock_kernel();
-
- return (rval == -EINVAL) ? -ENOIOCTLCMD : rval;
-}
-
static int
-dasd_ioctl_api_version(struct block_device *bdev, int no, long args)
+dasd_ioctl_api_version(void __user *argp)
{
int ver = DASD_API_VERSION;
- return put_user(ver, (int __user *) args);
+ return put_user(ver, (int *)argp);
}

/*
@@ -140,15 +89,13 @@ dasd_ioctl_api_version(struct block_devi
* used by dasdfmt after BIODASDDISABLE to retrigger blocksize detection
*/
static int
-dasd_ioctl_enable(struct block_device *bdev, int no, long args)
+dasd_ioctl_enable(struct block_device *bdev)
{
- struct dasd_device *device;
+ struct dasd_device *device = bdev->bd_disk->private_data;

if (!capable(CAP_SYS_ADMIN))
return -EACCES;
- device = bdev->bd_disk->private_data;
- if (device == NULL)
- return -ENODEV;
+
dasd_enable_device(device);
/* Formatting the dasd device can change the capacity. */
down(&bdev->bd_sem);
@@ -162,15 +109,13 @@ dasd_ioctl_enable(struct block_device *b
* Used by dasdfmt. Disable I/O operations but allow ioctls.
*/
static int
-dasd_ioctl_disable(struct block_device *bdev, int no, long args)
+dasd_ioctl_disable(struct block_device *bdev)
{
- struct dasd_device *device;
+ struct dasd_device *device = bdev->bd_disk->private_data;

if (!capable(CAP_SYS_ADMIN))
return -EACCES;
- device = bdev->bd_disk->private_data;
- if (device == NULL)
- return -ENODEV;
+
/*
* Man this is sick. We don't do a real disable but only downgrade
* the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
@@ -194,18 +139,13 @@ dasd_ioctl_disable(struct block_device *
* Quiesce device.
*/
static int
-dasd_ioctl_quiesce(struct block_device *bdev, int no, long args)
+dasd_ioctl_quiesce(struct dasd_device *device)
{
- struct dasd_device *device;
unsigned long flags;

if (!capable (CAP_SYS_ADMIN))
return -EACCES;

- device = bdev->bd_disk->private_data;
- if (device == NULL)
- return -ENODEV;
-
DEV_MESSAGE (KERN_DEBUG, device, "%s",
"Quiesce IO on device");
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
@@ -219,18 +159,13 @@ dasd_ioctl_quiesce(struct block_device *
* Quiesce device.
*/
static int
-dasd_ioctl_resume(struct block_device *bdev, int no, long args)
+dasd_ioctl_resume(struct dasd_device *device)
{
- struct dasd_device *device;
unsigned long flags;

if (!capable (CAP_SYS_ADMIN))
return -EACCES;

- device = bdev->bd_disk->private_data;
- if (device == NULL)
- return -ENODEV;
-
DEV_MESSAGE (KERN_DEBUG, device, "%s",
"resume IO on device");

@@ -302,25 +237,19 @@ dasd_format(struct dasd_device * device,
* Format device.
*/
static int
-dasd_ioctl_format(struct block_device *bdev, int no, long args)
+dasd_ioctl_format(struct block_device *bdev, void __user *argp)
{
- struct dasd_device *device;
+ struct dasd_device *device = bdev->bd_disk->private_data;
struct format_data_t fdata;

if (!capable(CAP_SYS_ADMIN))
return -EACCES;
- if (!args)
+ if (!argp)
return -EINVAL;
- /* fdata == NULL is no longer a valid arg to dasd_format ! */
- device = bdev->bd_disk->private_data;
-
- if (device == NULL)
- return -ENODEV;

if (device->features & DASD_FEATURE_READONLY)
return -EROFS;
- if (copy_from_user(&fdata, (void __user *) args,
- sizeof (struct format_data_t)))
+ if (copy_from_user(&fdata, argp, sizeof(struct format_data_t)))
return -EFAULT;
if (bdev != bdev->bd_contains) {
DEV_MESSAGE(KERN_WARNING, device, "%s",
@@ -335,17 +264,8 @@ dasd_ioctl_format(struct block_device *b
* Reset device profile information
*/
static int
-dasd_ioctl_reset_profile(struct block_device *bdev, int no, long args)
+dasd_ioctl_reset_profile(struct dasd_device *device)
{
- struct dasd_device *device;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EACCES;
-
- device = bdev->bd_disk->private_data;
- if (device == NULL)
- return -ENODEV;
-
memset(&device->profile, 0, sizeof (struct dasd_profile_info_t));
return 0;
}
@@ -354,31 +274,24 @@ dasd_ioctl_reset_profile(struct block_de
* Return device profile information
*/
static int
-dasd_ioctl_read_profile(struct block_device *bdev, int no, long args)
+dasd_ioctl_read_profile(struct dasd_device *device, void __user *argp)
{
- struct dasd_device *device;
-
- device = bdev->bd_disk->private_data;
- if (device == NULL)
- return -ENODEV;
-
if (dasd_profile_level == DASD_PROFILE_OFF)
return -EIO;
-
- if (copy_to_user((long __user *) args, (long *) &device->profile,
+ if (copy_to_user(argp, &device->profile,
sizeof (struct dasd_profile_info_t)))
return -EFAULT;
return 0;
}
#else
static int
-dasd_ioctl_reset_profile(struct block_device *bdev, int no, long args)
+dasd_ioctl_reset_profile(struct dasd_device *device)
{
return -ENOSYS;
}

static int
-dasd_ioctl_read_profile(struct block_device *bdev, int no, long args)
+dasd_ioctl_read_profile(struct dasd_device *device, void __user *argp)
{
return -ENOSYS;
}
@@ -388,18 +301,14 @@ dasd_ioctl_read_profile(struct block_dev
* Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
*/
static int
-dasd_ioctl_information(struct block_device *bdev, int no, long args)
+dasd_ioctl_information(struct dasd_device *device,
+ unsigned int cmd, void __user *argp)
{
- struct dasd_device *device;
struct dasd_information2_t *dasd_info;
unsigned long flags;
int rc;
struct ccw_device *cdev;

- device = bdev->bd_disk->private_data;
- if (device == NULL)
- return -ENODEV;
-
if (!device->discipline->fill_info)
return -EINVAL;

@@ -467,8 +376,8 @@ dasd_ioctl_information(struct block_devi
}

rc = 0;
- if (copy_to_user((long __user *) args, (long *) dasd_info,
- ((no == (unsigned int) BIODASDINFO2) ?
+ if (copy_to_user(argp, dasd_info,
+ ((cmd == (unsigned int) BIODASDINFO2) ?
sizeof (struct dasd_information2_t) :
sizeof (struct dasd_information_t))))
rc = -EFAULT;
@@ -480,68 +389,90 @@ dasd_ioctl_information(struct block_devi
* Set read only
*/
static int
-dasd_ioctl_set_ro(struct block_device *bdev, int no, long args)
+dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
{
- struct dasd_device *device;
- int intval, rc;
+ struct dasd_device *device = bdev->bd_disk->private_data;
+ int intval;

if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (bdev != bdev->bd_contains)
// ro setting is not allowed for partitions
return -EINVAL;
- if (get_user(intval, (int __user *) args))
+ if (get_user(intval, (int *)argp))
return -EFAULT;
- device = bdev->bd_disk->private_data;
- if (device == NULL)
- return -ENODEV;

set_disk_ro(bdev->bd_disk, intval);
- rc = dasd_set_feature(device->cdev, DASD_FEATURE_READONLY, intval);
-
- return rc;
+ return dasd_set_feature(device->cdev, DASD_FEATURE_READONLY, intval);
}

-/*
- * List of static ioctls.
- */
-static struct { int no; dasd_ioctl_fn_t fn; } dasd_ioctls[] =
-{
- { BIODASDDISABLE, dasd_ioctl_disable },
- { BIODASDENABLE, dasd_ioctl_enable },
- { BIODASDQUIESCE, dasd_ioctl_quiesce },
- { BIODASDRESUME, dasd_ioctl_resume },
- { BIODASDFMT, dasd_ioctl_format },
- { BIODASDINFO, dasd_ioctl_information },
- { BIODASDINFO2, dasd_ioctl_information },
- { BIODASDPRRD, dasd_ioctl_read_profile },
- { BIODASDPRRST, dasd_ioctl_reset_profile },
- { BLKROSET, dasd_ioctl_set_ro },
- { DASDAPIVER, dasd_ioctl_api_version },
- { -1, NULL }
-};
-
int
-dasd_ioctl_init(void)
+dasd_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
{
- int i;
+ struct block_device *bdev = inode->i_bdev;
+ struct dasd_device *device = bdev->bd_disk->private_data;
+ void __user *argp = (void __user *)arg;
+ struct dasd_ioctl *ioctl;
+ int rc;

- for (i = 0; dasd_ioctls[i].no != -1; i++)
- dasd_ioctl_no_register(NULL, dasd_ioctls[i].no,
- dasd_ioctls[i].fn);
- return 0;
+ if (!device)
+ return -ENODEV;
+
+ if ((_IOC_DIR(cmd) != _IOC_NONE) && !arg) {
+ PRINT_DEBUG("empty data ptr");
+ return -EINVAL;
+ }

+ switch (cmd) {
+ case BIODASDDISABLE:
+ return dasd_ioctl_disable(bdev);
+ case BIODASDENABLE:
+ return dasd_ioctl_enable(bdev);
+ case BIODASDQUIESCE:
+ return dasd_ioctl_quiesce(device);
+ case BIODASDRESUME:
+ return dasd_ioctl_resume(device);
+ case BIODASDFMT:
+ return dasd_ioctl_format(bdev, argp);
+ case BIODASDINFO:
+ return dasd_ioctl_information(device, cmd, argp);
+ case BIODASDINFO2:
+ return dasd_ioctl_information(device, cmd, argp);
+ case BIODASDPRRD:
+ return dasd_ioctl_read_profile(device, argp);
+ case BIODASDPRRST:
+ return dasd_ioctl_reset_profile(device);
+ case BLKROSET:
+ return dasd_ioctl_set_ro(bdev, argp);
+ case DASDAPIVER:
+ return dasd_ioctl_api_version(argp);
+ default:
+ /* resort to the deprecated dynamic ioctl list */
+ list_for_each_entry(ioctl, &dasd_ioctl_list, list) {
+ if (ioctl->no == cmd) {
+ /* Found a matching ioctl. Call it. */
+ if (!try_module_get(ioctl->owner))
+ continue;
+ rc = ioctl->handler(bdev, cmd, arg);
+ module_put(ioctl->owner);
+ return rc;
+ }
+ }
+ return -EINVAL;
+ }
}

-void
-dasd_ioctl_exit(void)
+long
+dasd_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
- int i;
+ int rval;

- for (i = 0; dasd_ioctls[i].no != -1; i++)
- dasd_ioctl_no_unregister(NULL, dasd_ioctls[i].no,
- dasd_ioctls[i].fn);
+ lock_kernel();
+ rval = dasd_ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
+ unlock_kernel();

+ return (rval == -EINVAL) ? -ENOIOCTLCMD : rval;
}

EXPORT_SYMBOL(dasd_ioctl_no_register);
-
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