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-rw-r--r--extras/multipath-tools/multipathd/sg_include.h43
1 files changed, 43 insertions, 0 deletions
diff --git a/extras/multipath-tools/multipathd/sg_include.h b/extras/multipath-tools/multipathd/sg_include.h
new file mode 100644
index 0000000000..460506826e
--- /dev/null
+++ b/extras/multipath-tools/multipathd/sg_include.h
@@ -0,0 +1,43 @@
+#ifdef SG_KERNEL_INCLUDES
+ #define __user
+ typedef unsigned char u8;
+ #include "/usr/src/linux/include/scsi/sg.h"
+ #include "/usr/src/linux/include/scsi/scsi.h"
+#else
+ #ifdef SG_TRICK_GNU_INCLUDES
+ #include <linux/../scsi/sg.h>
+ #include <linux/../scsi/scsi.h>
+ #else
+ #include <scsi/sg.h>
+ #endif
+#endif
+
+/*
+ Getting the correct include files for the sg interface can be an ordeal.
+ In a perfect world, one would just write:
+ #include <scsi/sg.h>
+ #include <scsi/scsi.h>
+ This would include the files found in the /usr/include/scsi directory.
+ Those files are maintained with the GNU library which may or may not
+ agree with the kernel and version of sg driver that is running. Any
+ many cases this will not matter. However in some it might, for example
+ glibc 2.1's include files match the sg driver found in the lk 2.2
+ series. Hence if glibc 2.1 is used with lk 2.4 then the additional
+ sg v3 interface will not be visible.
+ If this is a problem then defining SG_KERNEL_INCLUDES will access the
+ kernel supplied header files (assuming they are in the normal place).
+ The GNU library maintainers and various kernel people don't like
+ this approach (but it does work).
+ The technique selected by defining SG_TRICK_GNU_INCLUDES worked (and
+ was used) prior to glibc 2.2 . Prior to that version /usr/include/linux
+ was a symbolic link to /usr/src/linux/include/linux .
+
+ There are other approaches if this include "mixup" causes pain. These
+ would involve include files being copied or symbolic links being
+ introduced.
+
+ Sorry about the inconvenience. Typically neither SG_KERNEL_INCLUDES
+ nor SG_TRICK_GNU_INCLUDES is defined.
+
+ dpg 20010415, 20030522
+*/