Fred Isaman wrote: > On Tue, Feb 24, 2009 at 4:03 PM, Sam Ravnborg <sam@xxxxxxxxxxxx> wrote: >> On Tue, Feb 24, 2009 at 02:05:25PM -0500, Fred Isaman wrote: >>> The pnfs tree base of of 2.6.29-rc5 uses the new find_last_bit >>> function (defined in >>> lib/find_last_bit.c) in a file in the fs/nfs directory. Myself and >>> another developer (though no one else so far) get the following error >>> during compile: >>> >>> Kernel: arch/x86/boot/bzImage is ready (#5) >>> Building modules, stage 2. >>> MODPOST 515 modules >>> ERROR: "find_last_bit" [fs/nfs/nfs.ko] undefined! >>> make[2]: *** [__modpost] Error 1 >>> make[1]: *** [modules] Error 2 >>> make: *** [sub-make] Error 2 >>> >>> >>> Note that find_last_bit() is not used in any file in the fs directory. >>> If I add it to any function that is EXPORT_SYMBOL'ed >>> from the fs directory, suddenly the compile errors go away. (See the >>> below patch for a more concrete example.) >>> >>> I am not sure what is going on, and why it only affects some >>> developers, but it looks a lot like the kbuild system >>> is deciding that the library does not need to be included at the fs >>> directory level, so isn't including it in fs/nfs where >>> it is needed. >> kbuild only links in libaries if there is any users of siad library. >> And your normal config has no users of lib/find_last_bit.c so >> it is not linked into the kernel. >> > > I don't understand your comment. There *is* a user of the library in the > (modified) fs/nfs/nfs4proc.c. The problem is that it doesn't compile unless > there is also a user in some fs/*.c. If you build nfs (or pnfs) into the kernel image instead of as a loadable module, does the build succeed? I expect that it does (or would). >> The general rule is that if any in tree module uses a library >> then the library is always linked in. >> And to always link in a library you need to patch the Makefile >> as Randy suggest in his mail. >> >> Sam >> > > Again, I suspect I am misunderstanding. It seems you are suggesting > that to compile the nfs code I have to alter lib/Makefile. While that is a > useful workaround, that is certainly not a viable solution. Why not? We do that same change for other library options. -- ~Randy -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
