compat_sys_ioctl(): make parallel to do_vfs_ioctl()

Handle ioctls that might be handled without reaching ->ioctl() in
native case on the top level there.  The counterpart of vfs_ioctl()
(i.e. calling ->unlock_ioctl(), etc.) left as-is; eventually
that would turn simply into the call of ->compat_ioctl(), but
that'll take more work.  Once that is done, we can move the
remains of compat_sys_ioctl() into fs/ioctl.c and finally bury
fs/compat_ioctl.c.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index ce995d4..cec3ec0 100644 (file)
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -487,19 +487,7 @@ static unsigned int ioctl_pointer[] = {
 /* compatible ioctls first */
 /* Little t */
 COMPATIBLE_IOCTL(TIOCOUTQ)
-/* Little f */
-COMPATIBLE_IOCTL(FIOCLEX)
-COMPATIBLE_IOCTL(FIONCLEX)
-COMPATIBLE_IOCTL(FIOASYNC)
-COMPATIBLE_IOCTL(FIONBIO)
-COMPATIBLE_IOCTL(FIONREAD)  /* This is also TIOCINQ */
-COMPATIBLE_IOCTL(FS_IOC_FIEMAP)
-/* 0x00 */
-COMPATIBLE_IOCTL(FIBMAP)
-COMPATIBLE_IOCTL(FIGETBSZ)
 /* 'X' - originally XFS but some now in the VFS */
-COMPATIBLE_IOCTL(FIFREEZE)
-COMPATIBLE_IOCTL(FITHAW)
 COMPATIBLE_IOCTL(FITRIM)
 #ifdef CONFIG_BLOCK
 /* Big S */
@@ -540,8 +528,6 @@ COMPATIBLE_IOCTL(_IOR('p', 20, int[7])) /* RTCGET */
 COMPATIBLE_IOCTL(_IOW('p', 21, int[7])) /* RTCSET */
 /* Little m */
 COMPATIBLE_IOCTL(MTIOCTOP)
-/* Socket level stuff */
-COMPATIBLE_IOCTL(FIOQSIZE)
 #ifdef CONFIG_BLOCK
 /* md calls this on random blockdevs */
 IGNORE_IOCTL(RAID_VERSION)
@@ -971,19 +957,39 @@ COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
        if (error)
                goto out_fput;
 
-       /*
-        * To allow the compat_ioctl handlers to be self contained
-        * we need to check the common ioctls here first.
-        * Just handle them with the standard handlers below.
-        */
        switch (cmd) {
+       /* these are never seen by ->ioctl(), no argument or int argument */
        case FIOCLEX:
        case FIONCLEX:
+       case FIFREEZE:
+       case FITHAW:
+       case FICLONE:
+               goto do_ioctl;
+       /* these are never seen by ->ioctl(), pointer argument */
        case FIONBIO:
        case FIOASYNC:
        case FIOQSIZE:
-               break;
-
+       case FS_IOC_FIEMAP:
+       case FIGETBSZ:
+       case FICLONERANGE:
+       case FIDEDUPERANGE:
+               goto found_handler;
+       /*
+        * The next group is the stuff handled inside file_ioctl().
+        * For regular files these never reach ->ioctl(); for
+        * devices, sockets, etc. they do and one (FIONREAD) is
+        * even accepted in some cases.  In all those cases
+        * argument has the same type, so we can handle these
+        * here, shunting them towards do_vfs_ioctl().
+        * ->compat_ioctl() will never see any of those.
+        */
+       /* pointer argument, never actually handled by ->ioctl() */
+       case FIBMAP:
+               goto found_handler;
+       /* handled by some ->ioctl(); always a pointer to int */
+       case FIONREAD:
+               goto found_handler;
+       /* these two get messy on amd64 due to alignment differences */
 #if defined(CONFIG_X86_64)
        case FS_IOC_RESVSP_32:
        case FS_IOC_RESVSP64_32:
@@ -992,23 +998,8 @@ COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
 #else
        case FS_IOC_RESVSP:
        case FS_IOC_RESVSP64:
-               error = ioctl_preallocate(f.file, compat_ptr(arg));
-               goto out_fput;
-#endif
-
-       case FICLONE:
-               goto do_ioctl;
-       case FICLONERANGE:
-       case FIDEDUPERANGE:
-       case FS_IOC_FIEMAP:
-       case FIGETBSZ:
                goto found_handler;
-
-       case FIBMAP:
-       case FIONREAD:
-               if (S_ISREG(file_inode(f.file)->i_mode))
-                       break;
-               /*FALL THROUGH*/
+#endif
 
        default:
                if (f.file->f_op->compat_ioctl) {