* Theodore Tso <tytso@xxxxxxx> wrote: > On Wed, Nov 11, 2009 at 08:45:42AM +0100, Ingo Molnar wrote: > > Without an inode->vfs-name lookup/matching service it's of limited > > utility though to developers and users. So inode numbers are fine (as > > nicely unique physical identifiers)- as long as corresponding vfs name > > string is available too. > > Inode numbers are quite usable for me; but I'm not afraid to do > > debugfs /dev/sdb -R "ncheck 12345" > > :-) > > If you really want to avoid that, one relatively lightweight thing we > could do, which would avoid needing to dump the entire pathname out, > would be to print out the triple (devno, dir_ino, file_ino), and then > provide a privileged syscall which translates this to a user-visible > pathname. It won't be necessarily the pathname which the user used to > open the file (since there might be links, and bind mounts, et. al), > but if the goal is to give one of the user-friendly names of the inode > (as opposed to _the_ pathname used to open the file), it's quite > sufficient. Hm, why add a new syscall to retrieve the name we already had when the event happened? Also, why add a new syscall to retrieve something that might not exist anymore? (the VFS namespace is quite dynamic - post-processing to retrieve names is fundamentally racy) What matters most for analysis is the 'name of the moment' - the thing that the app used at that point. Arjan isnt doing this just randomly, he's one of the few people trying to speed up Linux booting - and this is the info he finds useful. We should give that information in a reasonable way, and the tracepoint he proposed looks pretty reasonable. Ingo -- 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
