On Wed, 19 November 2008 21:32:42 +0100, Jan Kara wrote: > > I have a problem in UDF so I thought I'll post it here if someone has a > good idea how to solve it. > UDF does preallocation on directories (on files a well, but that is not a > problem). Now this helps against directory fragmentation but there is an > issue with it: When to drop this preallocation? Currently it is done in > udf_clear_inode() which has two problems: > 1) udf_clear_inode() is really called to late to do anything like freeing > space from inode and UDF has to play some nasty tricks (like > explicitely syncing inode, calling invalidate_inode_buffers() once > more) to make everything work. Using udf_drop_inode() would be much > better but that is called under i_lock so it's not really usable > (unless I'd drop i_lock in it but then it would even nastier). > 2) When you create lots of directories, they use quite some additional > space for preallocation and there's not really a got way how to get rid > of preallocated blocks than dropping dcache or umount + mount the > filesystem. > > So after all I'm thinking whether directory preallocation is really worth > the trouble. But before I go and rip it I'd like to check whether someone > does not have some clever idea :). Problem 2 has lru written all over, don't you think? Problem 1 is similar to something I'm debugging this very moment. With some luck my solution might work for you as well. However, I don't see a big difference between files and directories yet. Maybe because there shouldn't be, or maybe because I've been missing something critical. Could you elaborate on that? Jörn -- It's just what we asked for, but not what we want! -- anonymous -- 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
