[PATCH] s390: use normal switch statement for ioctls in dasd_ioctlc

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@lst.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 86 insertions, 155 deletions

diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index f9930552ab54..e3ad34686444 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -77,62 +77,11 @@ dasd_ioctl_no_unregister(struct module *owner, int no, dasd_ioctl_fn_t handler)
         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_device *bdev, int no, long args)
  * 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. */
         mutex_lock(&bdev->bd_mutex);
@@ -162,15 +109,13 @@ dasd_ioctl_enable(struct block_device *bdev, int no, long args)
  * 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 *bdev, int no, long args)
  * 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 *bdev, int no, long args)
  * 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, struct format_data_t * fdata)
  * 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 *bdev, int no, long args)
  * 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_device *bdev, int no, long args)
  * 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_device *bdev, int no, long args)
  * 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_device *bdev, int no, long args)
         }
 
         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_device *bdev, int no, long args)
  * 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);