compat_ioctl: simplify the implementation

Now that both native and compat ioctl syscalls are
in the same file, a couple of simplifications can
be made, bringing the implementation closer together:

- do_vfs_ioctl(), ioctl_preallocate(), and compat_ioctl_preallocate()
  can become static, allowing the compiler to optimize better

- slightly update the coding style for consistency between
  the functions.

- rather than listing each command in two switch statements
  for the compat case, just call a single function that has
  all the common commands.

As a side-effect, FS_IOC_RESVSP/FS_IOC_RESVSP64 are now available
to x86 compat tasks, along with FS_IOC_RESVSP_32/FS_IOC_RESVSP64_32.
This is harmless for i386 emulation, and can be considered a bugfix
for x32 emulation, which never supported these in the past.

Reviewed-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 0 insertions, 6 deletions

diff --git a/fs/internal.h b/fs/internal.h
index 4a7da1df573d..d46247850ad7 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -180,11 +180,5 @@ extern void mnt_pin_kill(struct mount *m);
  */
 extern const struct dentry_operations ns_dentry_operations;
 
-/*
- * fs/ioctl.c
- */
-extern int do_vfs_ioctl(struct file *file, unsigned int fd, unsigned int cmd,
-		    unsigned long arg);
-
 /* direct-io.c: */
 int sb_init_dio_done_wq(struct super_block *sb);