On 02/05/2017 10:54 PM, Hans van Kranenburg wrote: > I was playing around with logical_to_ino and also implemented calling > ino_lookup today to create a program that will print all data extents in > a block group, and their related inodes and at least one filename per inode. > > https://github.com/knorrie/python-btrfs/commits/develop > See "examples: show filenames for data extents" > > I ran into the following behaviour of logical_to_ino: > > If the offset value in a backreference of an extent_item does not match > the offset value of the extent_data object in the fs tree, > logical_to_ino will skip the inode that uses data from the extent, and > not report it.
Ah, wait... To answer my own question... The reason is probably because the data at that exact place is not actually in use. -# btrfs inspect-internal logical-resolve 336064511 . (+ 16KiB - 1) -# btrfs inspect-internal logical-resolve 336064512 . (+ 16KiB) ./vmlinuz-4.9.0-1-amd64 -# btrfs inspect-internal logical-resolve 336064513 . ./vmlinuz-4.9.0-1-amd64 Jups... Makes sense. But, it also means that I cannot use logical_to_ino as a helper to expand shared backrefs to actual inode info... Meh. -- Hans van Kranenburg -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
