* tongcd (tongcd@21cn.com) wrote: > Could anybody give me some hint about the following question? Thanks > 1. I use linux security module to alloc a security blob to each inode, but when > i want to cleanup the module ,i decide to free these alloced memory from inode struct,i want to travel through inode_in_use ,inode_unused,sb->s_dirty and sb->s_locked_inode ,but these are all static varieble,where is no way to use it in lsm module,could it be other ways to do it? lsm attempts to make the minimal changes to the kernel required to meet its requirements. so static lists like you've mentioned have not been exported just for lsm. the proper way to handle this is to maintain your own list in your module of the allocations you've made. during the module_exit code, you can traverse these lists, and clean up after yourself. see the SELinux module for a good example of how to handle this. honestly, many lsm modules are coded with the intention that they will not be removed until the machine is being rebooted, and since lsm can control module unloading, this is not necessarily a bogus assumption. > why dte not do it? i'm sure serge would accept patches ;-) > 2. iget4 call find_inode to find establishing inode linked in i_hash,(these inode all in inode_in_used and inode_unused links??)why iget call get_new_inode which use find_inode for a second time? If this question has post before,i am sorry. it is possible for an inode to not be in hash. so the first attempt at find_inode in iget4 could fail. notice find_inode must be called with lock, so get_new_inode (which is called after the search failed, and the lock is released) must re-obtain the lock and re-check the hash. -chris -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ IRC Channel: irc.openprojects.net / #kernelnewbies Web Page: http://www.kernelnewbies.org/
