On Wed, Nov 25, 2009 at 08:20:02PM +0100, J?r?my Cochoy wrote: > Hello, > > There is something strange in iunique : what will happend if all inode > between max_reserved+1 and (unsinged in)(0-1) ? Will it make an > infinite loop or an interruption can happen and make an inode become > free? Another process can free an inode while this loop is executing. > In that case, it will be better to stop search when counter overflow, no? If you have all four billion inodes allocated, you have significantly bigger problems than this loop. For a start, at 600 bytes per inode, I'd like to see your machine with 2.4TB of memory. Then there's the size of your inode hash, and the depth of the chains within it. > Will it not be better to use a field max_ino_used (in superblock, for > exemple) where we store the last inode allocated with iunique and make > a search only if max_ino_used become to (unsigned)(-1) ? > > But, if iunique is here to provide a solution in order to generate > unused inode in filesystem which have various inode number, it's > better to use a list of used ino, in a short hash table which use the > first 8 bits of the inode, always use the same function to create a > new inode and look at the head if we can add a new inode with bigger > ino and still in the range. (But i think filesystems developper prefer > to write ther own functions in order to do that, no?) > > Well, if we want to stop in case of full inode filesystem, we can put > the first condition in the head and add change return as : > return inode->i_ino > max_reserved ? res : 0; // 0 might "i can't find > an inode after max_reserved" Gloves. http://thedailywtf.com/Articles/The_Complicator_0x27_s_Gloves.aspx -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- 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
