On Thu, Jan 12, 2017 at 06:16:35PM +0900, Nakajima Akira wrote: > Bug: > Duplicate inode number when mount --bind some directories to same > mountpoint. (from Fedora18 to 4.10-rc3) > Fedora17 and earlier works correctly.
Explain, please. "Duplicate inode number" between what and what? > And, > Above kernel ver 3.6 (Fedora18 including 4.10-rc3) creates many structs of > mount than ver 3.3 (Fedora17). > Is this a correct specification? > Looks kernel creates same many structs of mount. alloc_vfsmnt() and clone_mnt() are internal functions, no promises of stability had ever been given... As for the differences between these setups... almost certainly an effect of changed shared-subtree settings. Userland, not kernel. > [root@fedora17 home]# mkdir a b > [root@fedora17 home]# ls -i > 655540 a 655542 b > > [root@fedora17 home]# /root/mnt.stp & > [root@fedora17 home]# mount --bind a /mnt > [root@fedora17 home]# alloc_vfsmnt() new_mnt:0xffff880136bdaf00 > clone_mnt() mnt:0xffff880136bdaf00 d_iname:a inode:0xffff88013081cb00 > ino:655540 > > [root@fedora17 home]# mount --bind b /mnt > [root@fedora17 home]# alloc_vfsmnt() new_mnt:0xffff8801355b4f00 > clone_mnt() mnt:0xffff8801355b4f00 d_iname:b inode:0xffff88013081c790 > ino:655542 > > [root@fedora17 home]# ls -i > 655540 a 655542 b > Systemtap script result on Fedora25 > Kernel create many structs of mount. > And, inode number of "a" changes to 547586 of "b". > > > [root@fedora25 home]# mkdir a b > [root@fedora25 home]# ls -i > 547584 a 547586 b > > [root@fedora25 home]# /root/mnt.stp & > [root@fedora25 home]# mount --bind a /mnt > [root@fedora25 home]# clone_mnt() new_mnt:0xffff99e4b7cdc900 > do_mount() mnt:0xffff99e4b7cdc900 d_iname:a inode:0xffff99e4b9dcc948 > ino:547584 > clone_mnt() new_mnt:0xffff99e4b7cdcc00 > copy_tree() mnt:0xffff99e4b7cdcc00 d_iname:a inode:0xffff99e4b9dcc948 > ino:547584 > clone_mnt() new_mnt:0xffff99e4b7cdc000 > copy_tree() mnt:0xffff99e4b7cdc000 d_iname:a inode:0xffff99e4b9dcc948 > ino:547584 > clone_mnt() new_mnt:0xffff99e4b7cdc480 > copy_tree() mnt:0xffff99e4b7cdc480 d_iname:a inode:0xffff99e4b9dcc948 > ino:547584 > clone_mnt() new_mnt:0xffff99e4b7cdc180 > copy_tree() mnt:0xffff99e4b7cdc180 d_iname:a inode:0xffff99e4b9dcc948 > ino:547584 > > [root@fedora25 home]# mount --bind b /mnt > clone_mnt() new_mnt:0xffff99e4b7cb1480 > do_mount() mnt:0xffff99e4b7cb1480 d_iname:b inode:0xffff99e4b9dceac8 > ino:547586 > clone_mnt() new_mnt:0xffff99e4b7cb1180 > copy_tree() mnt:0xffff99e4b7cb1180 d_iname:b inode:0xffff99e4b9dceac8 > ino:547586 > clone_mnt() new_mnt:0xffff99e4b7cb1000 > copy_tree() mnt:0xffff99e4b7cb1000 d_iname:b inode:0xffff99e4b9dceac8 > ino:547586 > clone_mnt() new_mnt:0xffff99e436df9d80 > copy_tree() mnt:0xffff99e436df9d80 d_iname:b inode:0xffff99e4b9dceac8 > ino:547586 > clone_mnt() new_mnt:0xffff99e436df9600 > copy_tree() mnt:0xffff99e436df9600 d_iname:b inode:0xffff99e4b9dceac8 > ino:547586 > clone_mnt() new_mnt:0xffff99e436df9780 > copy_tree() mnt:0xffff99e436df9780 d_iname:b inode:0xffff99e4b9dceac8 > ino:547586 > clone_mnt() new_mnt:0xffff99e436df9a80 > copy_tree() mnt:0xffff99e436df9a80 d_iname:b inode:0xffff99e4b9dceac8 > ino:547586 > clone_mnt() new_mnt:0xffff99e436df9900 > copy_tree() mnt:0xffff99e436df9900 d_iname:b inode:0xffff99e4b9dceac8 > ino:547586 > clone_mnt() new_mnt:0xffff99e436df9c00 > copy_tree() mnt:0xffff99e436df9c00 d_iname:b inode:0xffff99e4b9dceac8 > ino:547586 > clone_mnt() new_mnt:0xffff99e436df9180 > copy_tree() mnt:0xffff99e436df9180 d_iname:b inode:0xffff99e4b9dceac8 > ino:547586 > clone_mnt() new_mnt:0xffff99e436df9480 > copy_tree() mnt:0xffff99e436df9480 d_iname:b inode:0xffff99e4b9dceac8 > ino:547586 > > [root@fedora25 home]# ls -i > 547586 a 547586 b What I would like to see is the contents of /proc/self/mountinfo - systemtap be damned, there is a sane interface for getting the mount tree setup. BTW, what's in that /root/mnt.stp thing?
