kernfs: Add API to generate relative kernfs path
The new function kernfs_path_from_node() generates and returns kernfs
path of a given kernfs_node relative to a given parent kernfs_node.
Signed-off-by: Aditya Kali <adityakali@google.com>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Changelog 20151125:
- Fully-wing multilinecomments
- Rework kernfs_path_from_node_locked() logic
- Replace BUG_ONs with returning NULL
- Use a const char* for /.. and precalculate its size
Changelog 20151130:
- Update kernfs_path_from_node_locked comment
Changelog 20151208:
- kernfs_node_distance:
* Remove BUG_ON(NULL)s
* Rename kernfs_node_distance to kernfs_depth
- kernfs_common-ancestor:
* Remove useless checks for depth == 0
* Add check to ensure nodes are from same root
- kernfs_path_from_node_locked:
* Remove needless __must_check
* Put p;len on its own decl line.
* Fix wrong WARN_ONCE usage
Changelog 20151209:
- kernfs_path_from_node: change arguments to 'to' and 'from', and
change their order.
Changelog 20151222:
- kernfs_path_from_node{,_locked}: return the string length.
kernfs_path is gpl-exported, so changing their return value seemed
ill-advised, but if noone minds I can update it too.
Changelog 20151223:
- don't allocate memory pr_cont_kernfs_path() under spinlock
2 files changed
