Hiya, please consider this:
~# truncate -s1G ./a ~# mkfs.btrfs ./a ~# sudo mount -o loop ./a /mnt/1 ~# cd /mnt/1 /mnt/1# ls /mnt/1# btrfs sub c A Create subvolume './A' /mnt/1# btrfs sub c A/B Create subvolume 'A/B' /mnt/1# touch A/inA A/B/inB /mnt/1# btrfs sub snap A A.snap Create a snapshot of 'A' in './A.snap' /mnt/1# zmodload zsh/stat /mnt/1# zstat +device ./**/* . 25 A 26 A/B 27 A/B/inB 27 A/inA 26 A.snap 28 A.snap/B 23 A.snap/inA 28 Why does A.snap/B have a different st_dev from A.snap's? Also: /mnt/1# touch A.snap/B/foo touch: cannot touch `A.snap/B/foo': Permission denied I can rmdir that directory OK though. Also note that the permissions are different: /mnt/1# ll A total 0 drwx------ 1 root root 6 Jun 2 00:54 B/ -rw-r--r-- 1 root root 0 Jun 2 00:54 inA /mnt/1# ll A.snap total 0 drwxr-xr-x 1 root root 0 Jun 2 01:29 B/ -rw-r--r-- 1 root root 0 Jun 2 00:54 inA If I create another snap of A or A.snap, the "B" in there gets the same st_dev (23). /mnt/1# btrfs sub create A.snap/B/C Create subvolume 'A.snap/B/C' ERROR: cannot create subvolume # btrfs sub snap A.snap/B B.snap ERROR: 'A.snap/B' is not a subvolume -- Stephane -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html