On Wed, Apr 13, 2016 at 09:41:10AM -0700, Christoph Hellwig wrote: > Al has been very unhappy about our destroy_inode abuse, and I'd > reluctant to make it worse. I don't have any problems with it at all. The VFS doesn't care how we manage inode allocation or destruction, so I don't see any problem with what we do outside the visibility of the VFS inode life cycle. > Why do we need to play games with i_mode when freeing? Because the inode cache lookup XFS code uses i_mode == 0 to detect a freed inode. i.e. in xfs_iget_cache_miss/xfs_iget_cache_hit this is used to allow XFS_IGET_CREATE to return a freed inodes still in the cache during inode allocation. This is the only case where we are allowed to find a freed inode in the cache lookup, so we have to be able to detect it somehow. Similarly, I'm pretty sure there are assumptions all through the XFS code (both kernel and userspace) that i_mode = 0 means the inode is free/unallocated. xfs_repair, for example, makes this assumption, and so we have to zero the mode when freeing the inode... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
