On Mon, Jul 17, 2017 at 03:51:50PM -0500, Eric Sandeen wrote: > > > On 06/28/2017 11:01 PM, Eric Sandeen wrote: > >> I guess there's also the problem that if inodesize != 512 then what are > >> we targeting, anyway? If inodesize = 256 then we can only hit > >> even-numbered inodes (not so bad) but if inodesize > 512 then do we jump > >> back to wherever the inode starts? Or just give the user what they > >> asked for, even if it's garbage? > > Oh, hum. Right, big inodes.... > > > > So I'm trying to go from disk location to inode number, but the current > > disk location may not even be the start of an inode. Hell. Well, I'm > > sure I could craft a test to disallow "type inode" if the current location > > cannot be on an inode boundary. But is that too clever? Should the > > debug tool just do what the user asks? > > > >> (FWIW I was fine with xfs_db being dumb and giving you exactly what you > >> point it at, even if that makes no sense. :P) > > yeah, if you do "daddr 0" "type agf" it'll squawk, too, so it's fine to > > do the dumb user's bidding... > > So as I have it today, issuing "type inode" will actually re-align you > to an inode offset even if you're not on one: > > xfs_db> sb 0 > xfs_db> addr rootino > xfs_db> daddr > current daddr is 128 > xfs_db> daddr 129 > xfs_db> type inode > xfs_db> daddr > current daddr is 128 > xfs_db> > > good? bad? indifferent? I'm thinking "bad" but we have no mechanism to > read a batch of inodes in xfs_db other than by passing in a legit inode number. > > And we have no mechanism to read only a /single/ inode... > > Maybe print a warning about the re-alignment and carry on? xfs_db is meant to be a developer tool, not idiot-proof. :P i.e. some knowledge of the layout of the metadata you are trying to examine is expected. I would not like xfs_db to change the daddr I've specified simply because I tried to parse it as the wrong object type.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
