Make the loop support stuff be much less evil, and make it cope

with 2.6.x asm/posix_types.h, which has done singularly evil thing
by yanking __kernel_dev_t and renaming it.  The loop interface was
really poorly designed in the first place.  The new 64 bit loop
interface looks to be somewhat less horrible, too bad it is only
present in 2.6.x kernels.
 -Erik


git-svn-id: svn://busybox.net/trunk/busybox@8418 69ca8d6d-28ef-0310-b511-8ec308f3f277

4 files changed, 34 insertions, 81 deletions

diff --git a/libbb/Makefile.in b/libbb/Makefile.in
index 979419b62..a656a5a53 100644
--- a/libbb/Makefile.in
+++ b/libbb/Makefile.in
@@ -96,9 +96,3 @@ $(LIBBB_MOBJS2): $(LIBBB_MSRC2)
 $(LIBBB_MOBJS3): $(LIBBB_MSRC3)
         $(CC) $(CFLAGS) $(EXTRA_CFLAGS) -DL_$(notdir $*) -c $< -o $@
 
-$(LIBBB_DIR)loop.o: $(LIBBB_DIR)loop.h
-
-$(LIBBB_DIR)loop.h: $(LIBBB_DIR)mk_loop_h.sh
-        @ $(SHELL) $< > $@
-
-
diff --git a/libbb/loop.c b/libbb/loop.c
index 7dba3e274..4d73dc4cc 100644
--- a/libbb/loop.c
+++ b/libbb/loop.c
@@ -26,7 +26,40 @@
 #include <unistd.h>
 #include <sys/ioctl.h>
 #include "libbb.h"
-#include "loop.h" /* Pull in loop device support */
+
+/* Grumble...  The 2.6.x kernel breaks asm/posix_types.h
+ * so we get to try and cope as best we can... */
+#include <linux/version.h>
+#include <asm/posix_types.h>
+#if LINUX_VERSION_CODE >= 132608
+#define __bb_kernel_dev_t   __kernel_old_dev_t
+#elif LINUX_VERSION_CODE >= 0x20600
+#define __bb_kernel_dev_t   __kernel_dev_t
+#else
+#define __bb_kernel_dev_t   unsigned short
+#endif
+
+/* Stuff stolen from linux/loop.h */
+#define LO_NAME_SIZE        64
+#define LO_KEY_SIZE         32
+#define LOOP_SET_FD         0x4C00
+#define LOOP_CLR_FD         0x4C01
+#define LOOP_SET_STATUS     0x4C02
+#define LOOP_GET_STATUS     0x4C03
+struct loop_info {
+        int                lo_number;
+        __bb_kernel_dev_t  lo_device;
+        unsigned long      lo_inode;
+        __bb_kernel_dev_t  lo_rdevice;
+        int                lo_offset;
+        int                lo_encrypt_type;
+        int                lo_encrypt_key_size;
+        int                lo_flags;
+        char               lo_name[LO_NAME_SIZE];
+        unsigned char      lo_encrypt_key[LO_KEY_SIZE];
+        unsigned long      lo_init[2];
+        char               reserved[4];
+};
 
 extern int del_loop(const char *device)
 {
diff --git a/libbb/mk_loop_h.sh b/libbb/mk_loop_h.sh
deleted file mode 100755
index 71c987376..000000000
--- a/libbb/mk_loop_h.sh
+++ /dev/null
@@ -1,37 +0,0 @@
-#!/bin/sh
-#
-# Figure out (i) the type of dev_t (ii) the defines for loop stuff
-#
-# Output of this script is normally redirected to "loop.h".
-
-# Since 1.3.79 there is an include file <asm/posix_types.h>
-# that defines __kernel_dev_t.
-# (The file itself appeared in 1.3.78, but there it defined __dev_t.)
-# If it exists, we use it, or, rather, <linux/posix_types.h> which
-# avoids namespace pollution.  Otherwise we guess that __kernel_dev_t
-# is an unsigned short (which is true on i386, but false on alpha).
-
-# BUG: This test is actually broken if your gcc is not configured to
-# search /usr/include, as may well happen with cross-compilers.
-# It would be better to ask $(CC) if these files can be found.
-
-if [ -f /usr/include/linux/posix_types.h ]; then
-   echo '#include <linux/posix_types.h>'
-   echo '#undef dev_t'
-   echo '#define dev_t __kernel_dev_t'
-else
-   echo '#undef dev_t'
-   echo '#define dev_t unsigned short'
-fi
-
-# Next we have to find the loop stuff itself.
-# First try kernel source, then a private version.
-
-if [ -f /usr/include/linux/loop.h ]; then
-   echo '#include <linux/loop.h>'
-else
-   echo '#include "real_loop.h"'
-fi
-
-echo '#undef dev_t'
-
diff --git a/libbb/real_loop.h b/libbb/real_loop.h
deleted file mode 100644
index 1bd7fa87a..000000000
--- a/libbb/real_loop.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- * include/linux/loop.h
- *
- * Written by Theodore Ts'o, 3/29/93.
- *
- * Copyright 1993 by Theodore Ts'o.  Redistribution of this file is
- * permitted under the GNU Public License.
- */
-
-#define LO_NAME_SIZE    64
-#define LO_KEY_SIZE     32
-       
-struct loop_info {
-        int             lo_number;      /* ioctl r/o */
-        dev_t           lo_device;      /* ioctl r/o */
-        unsigned long   lo_inode;       /* ioctl r/o */
-        dev_t           lo_rdevice;     /* ioctl r/o */
-        int             lo_offset;
-        int             lo_encrypt_type;
-        int             lo_encrypt_key_size;    /* ioctl w/o */
-        int             lo_flags;       /* ioctl r/o */
-        char            lo_name[LO_NAME_SIZE];
-        unsigned char   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
-        unsigned long   lo_init[2];
-        char            reserved[4];
-};
-
-#define LO_CRYPT_NONE   0
-#define LO_CRYPT_XOR    1
-#define LO_CRYPT_DES    2
-#define LO_CRYPT_IDEA   3
-#define MAX_LO_CRYPT    4
-
-#define LOOP_SET_FD     0x4C00
-#define LOOP_CLR_FD     0x4C01
-#define LOOP_SET_STATUS 0x4C02
-#define LOOP_GET_STATUS 0x4C03