On Thu, Mar 17, 2011 at 01:45:33PM +0800, Xiaotian Feng wrote: > I guess we need also switch pstore from ->get_sb() to ->mount() > > fs/pstore/inode.c:253: error: unknown field ???get_sb??? specified in initializer > fs/pstore/inode.c:253: warning: initialization makes integer from > pointer without a cast > fs/pstore/inode.c:253: error: initializer element is not computable at load time > fs/pstore/inode.c:253: error: (near initialization for > ???pstore_fs_type.fs_flags???) Yes. I've just looked at that thing and I see several, er, issues. a) What the hell would you expect to happen if userland mounts it twice and unmount the first one? pstore_sb = NULL, pstore_mnt = NULL, AFAICS. b) pstore_writefile() - struct file on stack? Really? Again, in the scenario above, what'll happen to you if pstore_mnt gets dropped and freed in the middle of all that? c) in the same function: + memset(&f, '0', sizeof f); Ahem... d) + if (pstore_is_mounted()) + pstore_mkfile(PSTORE_TYPE_DMESG, psinfo->name, id, + psinfo->buf, hsize + l1_cpy + l2_cpy, + CURRENT_TIME, psinfo->erase); And what happens if it's unmounted between the check and use? pstore_mkfile() pretty much starts with dereferencing pstore_sb... e) as the matter of fact, what happens if it's unmounted in the _middle_ of pstore_mkfile()? f) in general it's a lousy policy to tie that kind of difference in behaviour to "somebody has it mounted someplace at the moment", even without the races a-la (a)... -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
