>From the benchmark and the experimental inores patch on ext4, it can be found that inode reservation on ext4 is a good idea to be tried. One of the original idea of inode reservation is NOT modifying on-disk format. Current magic inode can make it, but use a magic inodes list to link each reserved inode block together is not a good idea. Indeed, this is a performance killer. 1, Therefor, group descriptor has to be modified to add a new member --- this new member records the lastest reserved inode in inode table of each block group. 2, Use rest room in magic inode (sizeof(ext4_inode) - sizeof(ext4_magic_inode)) to record other reserved inode blocks. This method can reduce number of magic inodes, which can minimize I/O for magic inodes. 3, Use magic inode cache. Most of the magic inode accessings are reading (not writing), therefore, caching can help to reduce most of the read I/O for magic inode. 4, Modify mke2fs to support new on-disk layout for inode reservation. Coly - 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
