dm ioctl: prepare for crypt key wiping

Prepare code for implementing buffer wipe flag.
No functional change in this patch.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 6d12775a1061059e483fdbeab3bf7b6ccbe53011..3a8f6a0e6eb5b7d58a64ea650775e481a774963a 100644 (file)
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1501,11 +1501,6 @@ static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
        return r;
 }
 
-static void free_params(struct dm_ioctl *param)
-{
-       vfree(param);
-}
-
 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
 {
        struct dm_ioctl tmp, *dmi;
@@ -1520,13 +1515,15 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
        if (!dmi)
                return -ENOMEM;
 
-       if (copy_from_user(dmi, user, tmp.data_size)) {
-               vfree(dmi);
-               return -EFAULT;
-       }
+       if (copy_from_user(dmi, user, tmp.data_size))
+               goto bad;
 
        *param = dmi;
        return 0;
+
+bad:
+       vfree(dmi);
+       return -EFAULT;
 }
 
 static int validate_params(uint cmd, struct dm_ioctl *param)
@@ -1564,7 +1561,7 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
        unsigned int cmd;
        struct dm_ioctl *uninitialized_var(param);
        ioctl_fn fn = NULL;
-       size_t param_size;
+       size_t input_param_size;
 
        /* only root can play with this */
        if (!capable(CAP_SYS_ADMIN))
@@ -1605,6 +1602,7 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
         * Copy the parameters into kernel space.
         */
        r = copy_params(user, &param);
+       input_param_size = param->data_size;
 
        current->flags &= ~PF_MEMALLOC;
 
@@ -1615,9 +1613,8 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
        if (r)
                goto out;
 
-       param_size = param->data_size;
        param->data_size = sizeof(*param);
-       r = fn(param, param_size);
+       r = fn(param, input_param_size);
 
        /*
         * Copy the results back to userland.
@@ -1625,8 +1622,8 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
        if (!r && copy_to_user(user, param, param->data_size))
                r = -EFAULT;
 
- out:
-       free_params(param);
+out:
+       vfree(param);
        return r;
 }